JP2001050854A - Drift correction factor calculating method for leak inspection, drift correcting method, leak inspection method, drift correction factor learnion method and leak inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a leak inspection apparatus easy to handle. SOLUTION: A gas pressure is applied to both a sample 20 and a reference tank 21, the change of the difference pressure therebetween is measured at fixed time intervals to obtain pressure difference change values ΔP1, ΔP2, a drift correction factor K=ΔP2/(ΔP1-ΔP2) is obtained from these pressure difference change values, a drift value J is obtained according to J=(ΔP1'-ΔP2')K, and a corrected drift value S is obtained according to S=ΔP2-J. The drift correction factor is stored in a memory means and read out in use at an inspection mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drift correction coefficient calculating method, a drift correction method, a drift correction coefficient learning method, a leakage inspection method, and a leakage inspection method used for a leakage inspection for inspecting the presence or absence of leakage of various containers and the like. The present invention relates to a leak inspection device that operates by using.

[0002]

2. Description of the Related Art Conventionally, products or parts which need to be free from leaks in use are sequentially inspected on their production process lines to judge the quality of the products or parts. FIG. 30 is a block diagram showing a general configuration of this type of leakage inspection apparatus. A flow tube 10 connected to an output side of a pneumatic source 11 is connected to a three-way solenoid valve 14 via a pressure regulating valve 12 and a three-way solenoid valve 14.
The outlet of the one-way solenoid valve 14 branches into branch pipes 15A and 15B. A pressure gauge 13 for setting an inspection pressure is connected between an outlet side of the pressure regulating valve 12 and an inlet side of the three-way solenoid valve 14.

A branch pipe 15A is connected to a conduit 1 via an electromagnetic valve 16.
At the other end of the conduit 18 is provided a connection jig 24 to which an object 20 to be inspected for leakage can be connected. The inspection objects 20 are sequentially connected by the connection jig 24 so that the inspection can be performed. On the other hand, the branch pipe 15B is connected to one end of a conduit 19 via an electromagnetic valve 17, and the other end of the conduit 19 is connected to a reference tank 21. At the outlet side of the solenoid valves 16 and 17, conduits 18A and 19A are respectively branched off and taken out, and a differential pressure detector 22 is mounted between the respective ends.

The output signal of the differential pressure detector 22 is supplied to a comparator 32 via an auto-zero reset type amplifier 31 so that the comparator 32 can compare with a reference value of a reference signal setter 33. The test object 20 is attached to the end of the conduit 18, the reference tank 21 having no leakage is attached to the conduit 19, the space between a and b of the three-way solenoid valve 14 is closed, the pressure regulating valve 12 is opened, and the pressure gauge 13 is opened. Is adjusted so that a predetermined air pressure from the air pressure source 11 is obtained. Solenoid valves 16 and 1
7 is opened, the space between a and b of the three-way solenoid valve 14 is opened, and a set constant air pressure is applied to the branch pipes 15A, 15B,
These are supplied to a test object 20 and a reference tank 21 through conduits 18 and 19, respectively.

After a predetermined time has passed and the pressures in the test object 20 and the reference tank 21 have stabilized, the solenoid valves 16 and 17
Is closed. Further, after a predetermined stabilization time (equilibrium time), the output signal of the auto-zero reset type amplifier 31 connected to the differential pressure detector 22 is read. Inspection object 20
In a state where the airtightness is complete and no leak exists, the amplifier 31
Is ideally zero after a certain detection time. When the test object 20 has a leak, an output signal that gradually decreases when the internal pressure is positive pressure and gradually increases when the internal pressure is negative pressure is obtained, and the output signal within a certain detection time is negative or positive. The value is almost proportional to the leakage amount.

[0006] The reference differential pressure value provided from the reference signal setting device 33 and the output value of the amplifier 31 are compared by a comparator 32, and depending on whether or not the output signal exceeds the reference differential pressure value, a pass / fail indicating a good or defective product. The judgment output 35 is obtained. In this general leak tester, even if the reference tank 21 has exactly the same shape as the test object 20 and does not leak, the differential pressure is detected mainly by the temperature difference between the test object 20 and the reference tank 21. Of the pressure difference generated in the vessel 22. If the shapes of the test object 20 and the reference tank 21 are different, when the gas is pressurized, a temperature difference occurs in the gas in a process in which the gas temperature rise due to adiabatic change becomes equal to the temperature of the test object 20 and the reference tank 21. However, the output signal does not ideally become zero. That is, even if there is no leakage of the test object 20, the output signal during a certain detection time does not become an ideal zero state and usually shows a differential pressure value comparable to a positive or negative leakage amount. It is. The differential pressure value equivalent to this leakage amount is generally called a drift amount.

This situation will be described with reference to FIG. FIG.
Curve A shown in FIG. 1 is the amount of drift, curve B is the amount of leakage, and curve C
Is a differential pressure detector 22 substantially obtained by adding a leak amount to a drift amount.
5 shows a differential pressure value detected by the above method. As can be seen from the drawing, most of the differential pressure value indicated by the curve C is the drift amount, and the differential pressure value corresponding to the leakage amount is small. As a method of extracting only the amount of leakage from this differential pressure value (curve C), the amount of increase in the differential pressure value generated due to the drift approaches zero over time, whereas the amount of the differential pressure generated due to the leakage amount increases. The value exhibits a phenomenon of increasing at a constant increasing rate forever, even when time elapses.

Focusing on this point, in the leakage inspection apparatus having the configuration shown in FIG. 30, the output of the auto-zero reset type amplifier 31 is set to a certain time (timing after the rate of increase of the drift amount approaches 0) TIM1 (FIG. 31) The reset signal is forcibly reset to zero. After the zero reset, the gain is increased to amplify the detection signal of the differential pressure detector 22 to obtain an output signal SD (curve D). Supply,
The output signal SD generated after a predetermined time is compared with the reference value by the comparator 32. If the output signal SD exceeds the reference value at the time when the predetermined time has elapsed, it is determined that the output signal SD is defective.

According to this detection method, the inspection is started after the rate of increase of the drift amount approaches zero, so that the influence of the drift can be eliminated. However, on the other hand, there is a disadvantage that the inspection time required for one inspection object is increased to about several tens of seconds. In order to solve this drawback, a leak inspection method as shown in FIG. 32 has been proposed. In this inspection method, in the calibration mode, the differential pressure generation value generated in the differential pressure detector 22 is reset to zero at a constant unit time by, for example, the auto-zero reset type amplifier 31 described with reference to FIG. This is repeated until the change value converges to a constant value. When the differential pressure change value per unit time converges to a constant value, the converged differential pressure change value Db is obtained. This differential pressure change value Db indicates a differential pressure value per unit time that occurs with a true leak amount.

Therefore, by obtaining Da-Db = D1 by subtracting Db from the initial differential pressure change value Da, the difference value D1 can be regarded as a drift value due to disturbance such as temperature. Therefore, by storing the value D1 as a drift correction value, in the subsequent inspection mode, a pressurized gas is applied to the test object 20, and the drift correction value D1 is calculated from the first differential pressure generation value immediately after the pressurization equilibrium. By subtracting
The differential pressure value Db corresponding to the true leak amount of each test object 20 can be obtained.

[0011]

In the calibration method shown in FIG. 32, correct leakage inspection can be performed only in a temperature environment (air temperature, temperature of the inspection object 20) in which the calibration mode is executed. However, when the air temperature or the temperature of the device under test 20 deviates from the condition of the calibration mode in which the drift correction value D1 is obtained, the calibration mode must be executed each time and the drift correction value D1 must be obtained again.

In the above description, the example of the differential pressure detection type leakage inspection device shown in FIG. 30 has been described. However, as shown in FIG. Drift similarly occurs in a leak inspection device of the type that measures by the measuring device 23 and determines whether or not there is a leak based on whether the gas pressure sealed in the inspection object 20 changes by a predetermined value or more. The same drawbacks as the leak inspection apparatus occur.

An object of the present invention is to provide a drift correction coefficient calculating method capable of continuing to execute an accurate leak test in a short time irrespective of a temperature change, and a drift correction coefficient calculated by the drift correction coefficient calculating method. The present invention proposes a drift correction method for correcting a drift amount using the method, a drift correction coefficient learning method, a leakage inspection method and a leakage inspection device using each of these methods.

[0014]

According to a first aspect of the present invention, a positive or negative gas pressure is applied to an object to be inspected and a reference tank,
At the time when a predetermined time has elapsed, it is determined whether or not a differential pressure equal to or more than a predetermined value is generated between the two components. A positive or negative gas pressure is applied to the leak-free test object and the reference tank, and the time T1 and (α-1) T1 from the end of pressurization equilibrium.
Each time (α is a positive integer of 2 or more) elapses, the differential pressure change values ΔP1 and ΔP2 generated between the test object and the reference tank are measured, and the drift correction coefficient K is calculated from the differential pressure change values ΔP1 and ΔP2. A method of calculating a drift correction coefficient used for a leak inspection calculated by K = ΔP2 / {ΔP1 (α−1) −ΔP2} is proposed. Note that the reference tank does not have to have the same shape as the object to be inspected, and a tank having better temperature stability when a positive or negative gas pressure is applied than the object to be inspected can be used.

According to a second aspect of the present invention, a positive or negative gas pressure is applied to the test object and the reference tank, and when a predetermined time has elapsed, whether or not a differential pressure equal to or more than a predetermined value is generated between the two. In the calibration mode of the leak inspection device which determines whether there is a leak in the inspected object, a leaked inspected object is attached to a mounting portion of the inspected object, and the leaked inspected object and the reference tank are mounted on the inspection tank. A positive or negative gas pressure is applied, and every time the time T1 and (α-1) T1 elapse from the end of the pressurization equilibrium, the differential pressure change value ΔP generated between the test object and the reference tank
1 and ΔP2 are measured, and when the change in the differential pressure generated between the test object and the reference tank stabilizes within a predetermined value range, it corresponds to the leak of the test object obtained at time (α-1) T1. The differential pressure change value ΔC is measured, and these differential pressure change values ΔP1 are measured.
And ΔP2 and ΔC, the drift correction coefficient K is calculated as K = (Δ
A method of calculating a drift correction coefficient used for a leak inspection calculated by (P2-ΔC) / {ΔP1 (α-1) -ΔP2} is proposed.

According to the drift correction coefficient calculation method proposed in claim 2, there is an advantage that the drift correction coefficient can be obtained without preparing a leak-free test object. According to a third aspect of the present invention, in the inspection mode, the test object and the reference tank are connected to the reference object every time the time T1 and the time (α-1) T1 elapse from the end of the positive or negative gas pressure equilibrium. Differential pressure change value ΔP generated between tank and tank
1 ′ and ΔP2 ′ are actually measured, and the actually measured differential pressure change value Δ
The drift amount J included in the differential pressure change value ΔP2 ′ is calculated by J = ｛ΔP1 ′ (α−1) −ΔP2 with respect to P1 ′ and ΔP2 ′ using the drift correction coefficient K calculated in claim 1 or 2.
A method of calculating the amount of drift calculated by 'に よ り K is proposed.

According to a fourth aspect of the present invention, a positive or negative gas pressure is applied to the object to be inspected and the reference tank, and when a predetermined time has elapsed, it is determined whether a differential pressure equal to or more than a predetermined value is generated between the two. In the leak inspection method for determining whether or not the inspection object has a leak, the drift amount J calculated in claim 3 is subtracted from a differential pressure change value ΔP2 ′ obtained by actually measuring S = ΔP2′−
J and proposes a drift correction method for obtaining a differential pressure change value S corresponding to the drift corrected leak.

According to a fifth aspect of the present invention, the differential pressure change value S calculated in the fourth aspect is compared with a set value, and depending on whether the differential pressure change value S is larger or smaller than the set value, leakage of the test object is determined. We propose a leak inspection method to determine the presence or absence. According to a sixth aspect of the present invention, a pneumatic source for applying a positive or negative gas pressure to the test object and the reference tank, and a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank are applied. A differential pressure measuring means for measuring a differential pressure change value generated between the test object and the reference tank after the pressure equilibration is completed, and a test object having no leakage connected to a connection portion of the test object in the calibration mode, The gas pressure is applied to the test object and the reference tank without the pressure, and after the pressure equilibration of the gas pressure is completed, the differential pressure change values ΔP1 and ΔP2 measured by the differential pressure measuring means each time the time T1 and (α-1) T1 elapse. Capture
Drift correction coefficient calculating means for calculating a drift correction coefficient K by K = ΔP2 / {ΔP1 (α-1) -ΔP2} based on the differential pressure change values ΔP1 and ΔP2, and a drift correction coefficient calculated by the drift correction coefficient calculating means A drift correction coefficient storing means for storing gas pressure from the pneumatic source to the test object and the reference tank in the test mode, and measuring the differential pressure at time intervals T1 and (α-1) T1 after the application is completed. The differential pressure change values ΔP1 ′ and ΔP2 ′ are measured by the means, and the drift amount J included in the differential pressure change value ΔP2 ′ is calculated from the differential pressure change values ΔP1 ′ and ΔP2 ′ by J = ｛ΔP1 ′ (α
−1) −ΔP2 ′｝ K, and the drift amount J
Is calculated from the differential pressure change value S = ΔP2′−J obtained by dividing the differential pressure value from the differential pressure change value ΔP2 ′, and the differential pressure change value S drift-corrected by the drift correction means is compared with a set value. Then, there is proposed a leakage inspection device configured by: a determination unit that determines that the inspection object has leakage when the differential pressure change value S exceeds a set value.

According to a seventh aspect of the present invention, a pneumatic pressure source for applying a positive or negative gas pressure to the test object and the reference tank, and a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank. A differential pressure measuring means for measuring a differential pressure change value generated between the test object and the reference tank after the pressurization equilibrium is completed, and a test object having a leak at a connection portion of the test object in the calibration mode. The gas pressure is applied to the leaked test object and the reference tank, and after the pressurization equilibrium of the gas pressure is completed, the time T1 and (α−
1) When the differential pressure changes ΔP1 and ΔP2 measured by the differential pressure measuring means every time T1 elapses and when the differential pressure generated between the test object and the reference tank stabilizes from the end of the application of the gas pressure ( α-1) The differential pressure change value ΔC generated at the time T1 is taken in, and the drift correction coefficient K is calculated as K = (ΔP2−ΔC) / ｛ΔP1 using the differential pressure change values ΔP1, ΔP2, and ΔC.
(Α-1) -ΔP2｝, a drift correction coefficient calculating means, a drift correction coefficient storing means for storing the drift correction coefficient calculated by the drift correction coefficient calculating means, The gas pressure is applied to the tank from the pneumatic source, and after the pressurization equilibrium, the differential pressure change values ΔP1 ′ and ΔP2 ′ are measured by the differential pressure measuring means at a time interval equal to the time T1 and (α-1) T1. From the differential pressure change values ΔP1 ′ and ΔP2 ′, the differential pressure change value ΔP2
Is the drift amount J included in J ′ = J = ｛ΔP1 ′ (α−1)
Drift correction means which calculates by the differential pressure change value S = ΔP2′−J, which is calculated by −ΔP2 ′｝ K, and the drift amount J is divided from the differential pressure change value ΔP2 ′, and the drift correction means. Determining means for comparing the drift-corrected differential pressure change value S with a set value, and determining that there is a leak in the test object when the differential pressure change value S exceeds the set value;
The differential pressure change value S drift-corrected by the drift correction means.
Is compared with a set value, and when the differential pressure change value S exceeds the set value, a judging means for judging that the object to be inspected has a leak is proposed.

According to an eighth aspect of the present invention, a positive or negative gas pressure is applied to the object to be inspected, and the gas pressure applied to the object to be inspected changes when the equilibrium time of pressurization elapses. In the calibration mode of the leak inspection device that determines whether or not the inspection object has a leak, a leak-free inspection object is mounted on the mounting portion of the inspection object, and a positive or negative gas is applied to the leak-free inspection object. A pressure is applied, and a time T1 and (α
-1) Every time T1 elapses, the pressure change values ΔQ1 and ΔQ2 of the gas pressure applied to the test object are measured, and the drift correction coefficient K is calculated from the pressure change values ΔQ1 and ΔQ2 as K = ΔQ2 /
The present invention proposes a drift correction coefficient calculation method used for a leak test, which is calculated by {ΔQ1 (α-1) -ΔQ2} and stores a drift correction coefficient K.

According to the drift correction coefficient calculation method proposed in claim 8, there is an advantage that correct drift correction can be performed even with a leak inspection apparatus having a simple configuration in which gas pressure is applied only to the test object. According to a ninth aspect of the present invention, a positive or negative gas pressure is applied to the object to be inspected, and the gas leaks to the object to be inspected depending on whether or not the gas pressure applied to the object to be inspected changes when a predetermined time has elapsed. In the calibration mode of the leak inspection device to determine whether there is a leak test device, it is unknown whether there is a leak in the mounting portion of the test object is mounted, the gas pressure is applied to this test object, Time T from the end of pressurization equilibrium
Every time 1 and (α-1) T1 elapse, the pressure change values ΔQ1 and ΔQ2 of the gas pressure applied to the test object are measured, and the test is performed when the change in the gas pressure applied to the test object is stabilized. The pressure change value ΔC generated at time (α-1) T1 due to body leakage is measured, and these pressure change values ΔQ1,
The drift correction coefficient K is calculated from K = (Δ
Q2-ΔC) / {ΔQ1 (α-1) -ΔQ2}, and proposes a drift correction coefficient calculation method used for a leak inspection that stores the drift correction coefficient K.

According to the drift correction coefficient calculating method proposed in the ninth aspect, there is an advantage that the drift correction coefficient can be obtained without preparing a leak-free inspection object. According to a tenth aspect of the present invention, in the inspection mode, a positive or negative gas pressure is applied to the object to be inspected, and the inspection is performed every time the time T1 and (α-1) T1 elapse from the end of the pressurization equilibrium of the gas pressure. The pressure change values ΔQ1 ′ and ΔQ2 ′ of the gas pressure applied to the body are actually measured, and the actually measured pressure change values ΔQ1 ′
And ΔQ2 ′ and the drift correction coefficient K calculated in claim 8 or 9, the drift amount J included in the pressure change value ΔQ2 ′ is calculated as J = {ΔQ1 ′ (α−1) −ΔQ2 ′}.
A drift amount calculation method calculated by K is proposed.

According to an eleventh aspect of the present invention, a positive or negative gas pressure is applied to the test object, and when a predetermined time has elapsed, a differential pressure is generated in which the gas pressure applied to the test object exceeds a predetermined value. In the leak inspection method for determining whether there is a leak in the inspection object based on whether or not the drift amount J calculated in claim 10 is subtracted from the actually measured pressure change value ΔQ2 ′, S = ΔQ2′− J, a drift correction method for obtaining a drift corrected pressure change value S is proposed.

In a twelfth aspect of the present invention, the pressure change value S calculated in the eleventh aspect is compared with a set value, and the pressure change value S is calculated.
A leak inspection method for determining whether or not the inspected object is leaked depending on whether is larger or smaller than a set value is proposed. According to a thirteenth aspect of the present invention, an air pressure source for applying a positive or negative gas pressure to an object to be inspected, a pressure measuring means for measuring a change in the gas pressure applied to the object to be inspected, A leak-free test object is connected to the connection part of the body, a gas pressure is applied to the leak-free test object, and each time the time T1 and (α-1) T1 elapse after the pressurization equilibrium of the gas pressure is completed. Drift correction coefficient calculating means for taking in the pressure change values ΔQ1 and ΔQ2 measured by the pressure measuring means, and calculating the drift correction coefficient K from these pressure change values ΔQ1 and ΔQ2 by K = ΔQ2 / {ΔQ1 (α-1) -ΔQ2}. And a drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means, and applying a gas pressure from the pneumatic source to the object to be inspected in the inspection mode, and setting a time after completion of the pressurization equilibrium. T1 (Α-1) The pressure change values ΔQ1 ′, ΔQ2 ′ are actually measured by the pressure measuring means at a time interval equal to T1, and the drift amount J included in the pressure change value ΔQ2 ′ is calculated from the pressure change values ΔQ1 ′, ΔQ2 ′. J = ｛ΔQ1 '
(Α-1) -ΔQ2 ′｝ K, a drift correction means for calculating the drift-corrected pressure change value S by dividing the drift amount J from the pressure change value ΔQ2 ′ by S = ΔQ2′-J, A pressure change value that has been drift-corrected by the drift correction means is compared with a set value, and when the pressure change value S exceeds the set value, the determination means determines that there is a leak in the test object. Suggest.

According to a fourteenth aspect of the present invention, a pneumatic pressure source for applying a positive or negative gas pressure to an object to be inspected, a pressure measuring means for measuring a change in the gas pressure applied to the object to be inspected, A leaking test object is connected to a connection portion of the test object, a gas pressure is applied to the leaking test object, and after time T1 and (α-1) T1 elapse after the application of the gas pressure is completed. , The pressure change value ΔQ1 ′ measured by the pressure measuring means,
ΔQ2 ′ and the time (α−) when the pressure change of the gas pressure applied to the test object from the end of the application of the gas pressure is stabilized.
1) The pressure change value ΔC due to the leak generated at T1 is taken in, and the drift correction coefficient K is calculated as K = (ΔQ2−ΔC) / ｛ΔQ1 using these pressure change values ΔQ1, ΔQ2 and ΔC.
(Α-1) -ΔQ2}, a drift correction coefficient calculating means, a drift correction coefficient storing means for storing the drift correction coefficient calculated by the drift correction coefficient calculating means, and A gas pressure is applied from an air pressure source, and after the pressurization equilibrium, the pressure change values ΔQ1 ′ and ΔQ2 ′ are actually measured by the pressure measurement means at a time interval equal to the time T1 and (α-1) T1. From the values ΔQ1 ′ and ΔQ2 ′, the drift amount J included in the pressure change value ΔQ2 ′ is calculated by J = ｛ΔQ1 ′ (α−1) −ΔQ
2 ′｝ K, and calculate the drift amount J as the pressure change value Δ
The pressure change value S that has been drift-corrected by dividing from Q2 '
= ΔQ2′−J, and the pressure change value S drift-corrected by the drift correction means is compared with a set value. If the pressure change value S exceeds the set value, the pressure leaks to the test object. There is proposed a leakage inspection device configured by a determination unit that determines that there is the leakage inspection device.

According to a fifteenth aspect of the present invention, a positive or negative gas pressure is applied to the test object and the reference tank, and when a predetermined time has elapsed, it is determined whether or not a differential pressure equal to or more than a predetermined value is generated between the two. In the calibration mode of the leakage inspection device for determining whether the inspection object has a leak, a leak-free inspection object is mounted on a mounting portion of the inspection object, and the leak-free inspection object and the reference tank are mounted. Is applied, and the differential values a1, a2 of the differential pressure change at each timing are measured at each timing when the predetermined time TM1, TM2 elapses from the end of the pressurization equilibrium, and this differential value a1, A drift correction coefficient calculation method used for a leak inspection for calculating a drift correction coefficient K from a2 by K = a2 / (a1−a2) is proposed.

According to a sixteenth aspect of the present invention, a positive or negative gas pressure is applied to the test object and the reference tank, and when a predetermined time has elapsed, whether a differential pressure equal to or more than a predetermined value is generated between the two is determined. In the calibration mode of the leakage inspection device for determining whether or not the inspection object has a leak, the inspection object having the leakage is mounted on the mounting portion of the inspection object, and the inspection object having the leakage and the reference tank are mounted. And a differential value a1, a2 of the differential pressure change and the differential pressure change at each timing at predetermined timings TM1, TM2 from the end of the pressurization equilibrium at each timing. The differential value C1 at the time of convergence to the range is measured, and these differential values a1, a2,
The drift correction coefficient K is calculated by K = (a2-C1) /
A drift correction coefficient calculation method used for the leak inspection calculated by (a1-a2) is proposed.

According to a seventeenth aspect of the present invention, a positive or negative gas pressure is applied to the object to be inspected and the reference tank, and the object to be inspected is set every time a predetermined time TM1, TM2 elapses from the end of pressurization equilibrium of the gas pressure. 17. The differential value a1 ', a2' of the differential pressure change occurring between the test object and the reference tank is actually measured, and the actually measured differential value a1 ', a2' of the differential pressure change and the drift calculated in claim 15 or 16. Using the correction coefficient K, the drift amount J included in the differential values a1 ′ and a2 ′ is calculated by J = (a
1′-a2 ′) A drift amount calculation method calculated by K is proposed.

According to an eighteenth aspect of the present invention, a positive or negative gas pressure is applied to the test object and the reference tank, and when a predetermined time has elapsed, whether or not a differential pressure equal to or more than a predetermined value is generated between the two. In the leak inspection method for determining whether or not there is a leak in the test object, the drift amount J calculated in claim 17 is subtracted from the differential value a2 ′ of the differential pressure change obtained by actually measuring to correct the drift. A drift correction method for obtaining a differential value R of a differential pressure change is proposed.

According to a nineteenth aspect of the present invention, the differential value R of the differential pressure change calculated in the eighteenth aspect is compared with a set value, and an inspection is performed based on whether the differential value R of the differential pressure change is larger or smaller than the set value. We propose a leak inspection method for determining the presence or absence of body leaks. According to a twentieth aspect of the present invention, an air pressure source for applying a positive or negative gas pressure to the test object and the reference tank, and a gas having a predetermined pressure from the air pressure source to the test object and the reference tank, Differential pressure differentiating means for measuring differential values a1, a2 of a differential pressure change generated between the test object and the reference tank after the application is completed; Are connected to each other, gas pressure is applied to the leak-free test object and the reference tank, and the differential pressure differential means measures each time the predetermined time TM1, TM2 elapses from the end of pressurization equilibrium of the gas pressure. Drift correction coefficient calculating means for taking the values a1 and a2 and calculating the drift correction coefficient K from the differential values a1 and a2 of the differential pressure change by K = a2 / (a1-a2), and the drift correction coefficient calculating means Drift A drift correction coefficient storage means for storing a correction coefficient, and in the inspection mode, gas pressure is applied from the air pressure source to the test object and the reference tank, and the predetermined times TM1 and TM2 elapse after the pressurization equilibrium is completed. The differential values a1 'and a2' of the change in the differential pressure are actually measured by the differential pressure differentiating means at each timing when the differential values a1 'and a2 are obtained.
2 ′, the drift amount J included in the differential value a2 ′ of the differential pressure change is obtained by J = (a1′−a2 ′) K, and the drift amount J is divided by the differential value Δa2 ′ of the differential pressure change to correct the drift. A differential correction value R for calculating the differential value R of the differential pressure change by R = a2'-J, and a differential value R of the differential pressure change drift-corrected by the drift corrector is compared with a set value to differentiate the differential pressure change. And a determination unit that determines that the inspection object has leakage when the value R exceeds a set value.

According to a twenty-first aspect of the present invention, a pneumatic pressure source for applying a positive or negative gas pressure to a test object and a reference tank, and a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank. A differential pressure differentiating means for measuring differential values a1 and a2 of a differential pressure change generated between the test object and the reference tank after the application is completed, and a test device having a leak at a connection portion of the test object in the calibration mode. A test object is connected, gas pressure is applied to the leaked test object and the reference tank, and the differential pressure differential means measures at each time when a predetermined time TM1, TM2 elapses from the end of the gas pressure application. Differential values a1, a of pressure change
2 and the differential value C1 of the differential pressure change generated when the change in the differential pressure generated between the test object and the reference tank is stabilized from the end of the application of the gas pressure, and the differential value a1, a2, C1 is used to calculate the drift correction coefficient K as K =
Drift correction coefficient calculating means calculated by (a2-C1) / (a1-a2); drift correction coefficient storing means for storing the drift correction coefficient calculated by the drift correction coefficient calculating means; A gas pressure is applied to the body and the reference tank from the pneumatic source, and the differential pressure differentiating means a1 ′, a2 'is actually measured, and from the differential values a1' and a2 ', the drift amount J included in the differential value a2'
= (A1'-a2 ') K, this drift amount J
Is calculated from the differential value a2 'of the differential pressure change by the drift correction means R = a2'-J, and the differential value of the differential pressure change drift-corrected by the drift correction means is calculated. The present invention proposes a leak inspection device configured by comparing a differential value R with a set value and determining that the object to be inspected has leak when the differential value R of the differential pressure change exceeds the set value.

According to a twenty-second aspect of the present invention, a positive or negative gas pressure is applied to an object to be inspected, and the gas pressure applied to the object to be inspected changes at a point in time when a predetermined time has elapsed. In the calibration mode of the leak inspection device that determines whether or not the inspection object has a leak, a leak-free inspection object is mounted on the mounting portion of the inspection object, and a positive or negative gas is applied to the leak-free inspection object. The pressure is applied, and the differential values b1 and b2 of the pressure change of the gas pressure applied to the test object are measured at each timing when the predetermined time TM1 and TM2 elapse from the end of the pressurization equilibrium. From b2, the drift correction coefficient K
Is calculated by K = b2 / (b1−b2).

According to a twenty-third aspect of the present invention, a positive or negative gas pressure is applied to the object to be inspected, and whether or not the gas pressure applied to the object to be inspected changes after a predetermined time has elapsed is determined. In the calibration mode of the leakage inspection device for determining whether or not the inspection object has a leak, the leaking inspection object is mounted on a mounting portion of the inspection object, and gas pressure is applied to the leaking inspection object. A predetermined time TM1, T
The derivative values b1 and b2 of the pressure change of the gas pressure applied to the test object and the derivative value C1 are measured at the timing at which the pressure change converges within a predetermined numerical value at every timing when M2 elapses. The present invention proposes a drift correction coefficient calculation method used in a leak inspection for calculating a drift correction coefficient K = (b2-C1) / (b1-b2) using b1, b2, and C1.

According to a twenty-fourth aspect of the present invention, a positive or negative gas pressure is applied to the test object, and the positive or negative gas pressure is applied to the test object every time a predetermined time TM1, TM2 elapses from the end of the application of the gas pressure. Differential value b1 'of the change in gas pressure
A drift amount calculation method is proposed in which b2 'is measured, and the drift amount J is calculated from these differential values b1' and b2 'by J = (b1'-b2') K.

According to a twenty-fifth aspect of the present invention, a positive or negative gas pressure is applied to the test object, and when a predetermined time has elapsed, the gas pressure applied to the test object generates a differential pressure equal to or higher than a predetermined value. 25. A leak inspection method for determining whether or not there is a leak in an object to be inspected based on whether or not there is a leak, the drift amount J calculated in claim 24 being subtracted from a differential value b2 ′ of a pressure change obtained by actual measurement. A drift correction method for obtaining the differential value R of the corrected pressure change is proposed.

According to a twenty-sixth aspect of the present invention, the differential value R of the pressure change calculated in the twenty-fifth aspect is compared with a set value, and the differential value R of the pressure change is determined to be larger or smaller than the set value. We propose a leak inspection method for determining the presence or absence of leaks. According to a twenty-seventh aspect of the present invention, a pneumatic pressure source for applying a positive or negative gas pressure to a test object and a pressure differentiating means for measuring a differential value of a pressure change obtained by differentiating a change in the gas pressure applied to the test object. In the calibration mode, a leak-free test object is connected to the connection portion of the test object, a gas pressure is applied to the leak-free test object, and a predetermined time TM1 from the end of pressurization equilibrium of the gas pressure. And a drift correction coefficient calculating means for calculating and storing a drift correction coefficient K by K = b2 / (b1-b2) based on differential values b1 and b2 of the pressure change measured by the pressure differentiating means at each timing when the pressure TM2 elapses. A drift correction coefficient storage means for calculating and storing the drift correction coefficient by the drift correction coefficient calculation means; and applying a gas pressure from the pneumatic source to the object to be inspected in the inspection mode, and completing the pressurization equilibrium. The pressure differential means b1 'and b2' are actually measured by the pressure differentiating means at each timing when predetermined times TM1 and TM2 elapse, and the differential value b2 'of the pressure change is calculated from the differential values b1' and b2 'of the pressure change. ′ Is obtained from J = (b1′−b2 ′) K, and the drift amount J is divided by the differential value b2 ′ of the pressure change to obtain the differential value R of the drift-corrected R = b.
2′-J, and the differential value R of the pressure change drift-corrected by the drift correcting unit is compared with a set value. If the differential value R of the pressure change exceeds the set value, The present invention proposes a leakage inspection apparatus configured by: a determination unit that determines that the inspection object has leakage.

According to a twenty-eighth aspect of the present invention, a pneumatic pressure source for applying a positive or negative gas pressure to an object to be inspected, a pressure differentiating means for measuring a differential value of a change in the gas pressure applied to the object to be inspected,
In the calibration mode, a leaking test object is connected to the connection portion of the test object, a gas pressure is applied to the leaking test object, and a predetermined time TM1 from the end of pressurization equilibrium of the gas pressure. The differential values b1, b2 of the pressure change measured by the pressure differentiating means at each timing when TM2 elapses and the pressure change of the gas pressure applied to the test object from the end of the application of the gas pressure are within a predetermined numerical range. The differential value C1 of the pressure change at the time of convergence is taken in, and the drift correction coefficient K is calculated based on the differential values b1, b2, and C1 of these pressure changes.
Is calculated by K = (b2-C1) / (b1-b2),
Drift correction coefficient calculating means for storing, drift correction coefficient storing means for calculating and storing the drift correction coefficient by the drift correction coefficient calculating means, and applying a gas pressure from the pneumatic source to the object to be inspected in the inspection mode. The pressure differentiating means b1 calculates the differential value b1 of the pressure change by the pressure differentiating means at each timing when the predetermined times TM1 and TM2 elapse from the end of the application.
', B2' are actually measured, and the differential values b1 ', b
2 ′, the drift amount J included in the differential value b2 ′ of the pressure change is determined by J = (b1′−b2 ′) K, and the drift amount J is divided from the differential value b2 ′ of the pressure change to obtain a drift corrected pressure. A drift correction means for calculating a differential value R of the change by R = b2'-J, and a differential value R of the pressure change drift-corrected by the drift correction means being compared with a set value;
The present invention proposes a leakage inspection device including: a determination unit that determines that the inspection object has leakage when the differential value R of the pressure change exceeds a set value.

According to a twenty-ninth aspect of the present invention, in any one of the leak inspection apparatuses according to the sixth and seventh aspects, the temperature of the inner wall surface of the inspection object is obtained from the differential pressure change values ΔP1 and ΔP2 measured by the differential pressure measuring means.し た ΔP1 (α-1) −ΔP proportional to the difference between the temperature of the gas applied to the test object under pressure
2｝ is calculated, the calculated value is converted into an address signal by the address signal conversion processing means, and the drift correction coefficient means is accessed by the address signal, and the drift correction coefficient K obtained from the differential pressure change values ΔP1 and ΔP2 is used as the address. There is proposed a leakage inspection device configured to store an address accessed by a signal.

According to a thirtieth aspect of the present invention, in any one of the leak inspection apparatuses according to the thirteenth and fourteenth aspects, the temperature of the inner wall surface of the object to be inspected and the temperature of the object are measured based on the pressure change values Q1 and Q2 measured by the pressure measuring means. A value ｛ΔQ1 (α-1) -ΔQ proportional to the difference between the temperature of the gas pressurized and applied to the test object.
2｝ is calculated, the calculated value is converted into an address signal by the address signal processing means, and the drift correction coefficient storage means is accessed by the address signal, and the pressure change value ΔQ
There is proposed a leakage inspection apparatus configured to store the drift correction coefficient K obtained from 1 and ΔQ2 at an address accessed by an address signal.

According to a thirty-first aspect of the present invention, in any one of the leak inspection apparatuses according to the twentieth and twenty-first aspects, the differential value a1, a2 of the differential pressure change measured by the differential pressure differentiating means is used to determine the inner wall surface of the inspection object. And a value (a1-a2) proportional to the difference between the temperature of the test object and the temperature of the gas pressurized and applied to the test object, and the calculated value is converted into an address signal by an address signal processing means. The drift correction coefficient storage means is accessed by the address signal, and the differential value a1,
A leak inspection device configured to store the drift correction coefficient K obtained from a2 at an address accessed by an address signal.

According to a thirty-second aspect of the present invention, in any one of the leak inspection apparatuses according to the twenty-seventh and twenty-eighth aspects, the temperature of the inner wall surface of the inspection object is calculated from the differential values b1 and b2 of the pressure change measured by the pressure differentiating means. And a value (b1-b2) proportional to the difference between the temperature and the temperature of the gas pressurized and applied to the test object, and the calculated value is converted into an address signal by an address signal processing means. The drift correction coefficient storage means is accessed to obtain the differential value b of the pressure change.
A leak inspection device configured to store the drift correction coefficient K obtained from the first and b2 at an address accessed by an address signal.

According to a thirty-third aspect of the present invention, in any one of the leak inspection apparatuses according to the twenty-seventh to thirty-second modes, the temperature of the test object mounted on the mounting portion of the test object is varied by changing the temperature of the test object. Calculated value ｛ΔP corresponding to the difference in body temperature
1 (α-1) -ΔP2｝ or ｛ΔQ1 (α-1) -Δ
Q2｝, (a1-a2) and (b1-b2) are dispersed,
Leakage inspection in which an address signal having a multi-valued value is generated based on the scattered calculated value, and the drift correction coefficient is stored in as many addresses as possible prepared in the drift correction coefficient storage means using the multi-valued address signal. A method for learning the drift correction coefficient of the device is proposed.

According to a thirty-fourth aspect of the present invention, in the drift correction coefficient learning method according to the thirty-third aspect, in the leak inspection apparatus in which the drift correction coefficient is stored at a plurality of addresses of the drift correction coefficient storage means, the drift correction coefficient is stored at a plurality of addresses. A drift correction coefficient learning method, comprising interpolating means for interpolating and storing the drift correction coefficient by linear approximation even at an address where the storage of the drift correction coefficient does not exist based on the drift correction coefficient.

According to a thirty-fifth aspect of the present invention, in the leak inspection apparatus storing the drift correction coefficient by the drift correction coefficient learning method according to the thirty-third or thirty-fourth aspect, a plurality of storage areas are provided in the drift correction coefficient storage means. The present invention proposes a leakage inspection apparatus that selects one of a plurality of storage areas and writes and reads a drift correction coefficient.

According to a thirty-sixth aspect of the present invention, in the drift correction coefficient learning method according to the thirty-third aspect, the temperature of the test object is set to a normal temperature, and the address signal generated by the measured value obtained from the test object at the normal temperature. A leak inspection apparatus is proposed in which the address to be assigned to the drift correction coefficient storage means is determined based on the value of (1). According to a thirty-seventh aspect of the present invention, in the leak inspection apparatus storing the drift correction coefficient by any of the drift correction coefficient learning methods according to the thirty-third or thirty-fourth aspect, the calibration mode is executed, and the drift obtained in the calibration mode is executed. If the relationship between the value of the correction coefficient and the value of the drift correction coefficient stored in the address obtained in the calibration mode has a deviation within a predetermined range, each drift stored in each address of the drift correction coefficient storage means A leak inspection device is proposed which corrects the value of the correction coefficient by the same amount as the deviation.

According to a thirty-eighth aspect of the present invention, in the leak inspection apparatus for storing a drift correction coefficient in the drift correction storage means by the drift correction coefficient learning method according to the thirty-third aspect, a plurality of addresses are provided for each address of the drift correction coefficient storage means. There is proposed a leakage inspection apparatus provided with a storage unit and configured to be able to store the drift correction coefficient calculated with the same address value in the plurality of storage units.

According to a thirty-ninth aspect of the present invention, in the leak inspection apparatus according to the thirty-eighth aspect, averaging means for calculating an average value of a plurality of drift correction coefficients read from the same address is provided. We propose a leak inspection device that performs a leak inspection using the drift correction coefficient.

[0048]

The drift correction coefficient K calculated by the drift correction coefficient calculation method according to the present invention described above does not significantly change even if the inspection conditions greatly change. As a result, without depending on inspection conditions,
A stable drift correction coefficient K can be obtained.

As a result, the drift amount J calculated by the drift amount calculation method proposed in claims 3, 10, 17, and 24 is calculated.
Follows the change in the inspection condition, so that the correct drift amount can always be calculated. As a result, claims 4 and 1
According to the drift correction method proposed in 1, 18, and 25, correct drift correction can be performed even for a change in inspection conditions. Moreover, according to the leak inspection method proposed in claims 5, 12, 19, and 26, it is possible to realize a leak inspection without making an erroneous determination.

Further, according to the leak inspection apparatus proposed in claims 29 to 32 and the drift correction coefficient learning method proposed in claims 33 and 34, the drift correction coefficient is automatically stored and learned. Thus, it is possible to obtain a leak inspection device which is easy to handle.

[0051]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a leak inspection apparatus which operates by calculating a drift correction coefficient by a drift correction coefficient calculation method proposed in claim 1 of the present invention. In this embodiment, an air pressure (gas pressure) is applied from the air pressure source 11 to the test object 20 and the reference tank 21, and whether a differential pressure is generated in the differential pressure detector 22 when a predetermined time has elapsed after the application of the air pressure. An embodiment in which the present invention is applied to a differential pressure type leak inspection device that determines whether or not the test object 20 has a leak based on whether the test object 20 is leaked or not will be described.

In this embodiment shown in FIG. 1, the differential pressure detector 22
Is read at predetermined times T1 and (α-1) T1, and the differential pressure change values ΔP1 and ΔP2 generated each time the predetermined time T1 and (α-1) T1 (see FIG. 2) elapse are measured. The pressure change values ΔP1 and ΔP2 measured by the differential pressure change measurement means 40A.
, The drift correction coefficient K is calculated as K = ΔP2 / ｛ΔP1 (α−
1) A point provided with a drift correction coefficient calculating unit 53-3 calculated by -ΔP2}, a point provided with a drift correction coefficient storing unit 53-4, and a drift amount calculating and storing unit 53-5 calculating a drift amount J. , A leak amount calculating means 53-6 for subtracting the drift amount J from the differential pressure change value ΔP2 'actually measured in the inspection mode to calculate a differential pressure value S corresponding to the leak amount, and a determining means 53- 7 is provided.

Α can be set to any positive integer of 2 or more, and the value of α defines the time (α−1) T1 for measuring ΔP2. In the embodiment described below, a case where α is set to α = 2 will be described. When α = 2, the measurement times of the differential pressure change values ΔP1 and ΔP2 are both T1, as shown in FIG. 2, and are the same time. When α = 3, the time for measuring the differential pressure change value ΔP2 is 2T1, as shown in FIG.

The differential pressure change measuring means 40A includes an auto-zero reset type amplifier 41 which can be reset to a reset state by a reset signal, a reset signal generator 42 for inputting a reset signal to the auto-zero reset type amplifier 41, and an auto-zero reset type. It comprises a sample-and-hold circuit 43 for sampling the differential pressure signal output from the amplifier 41, and an AD converter 44 for AD-converting the differential pressure signal sampled and held by the sample-and-hold circuit 43.

In the calibration mode, the differential pressure change values ΔP1 and ΔP1
In order to measure P2, first, the test object 20, which has been confirmed to have no leakage, is mounted on the mounting portion of the test object 20, and air pressure is applied to the test object 20 and the reference tank 21 from the air pressure source 11, The valves 16 and 17 are controlled to be closed to allow a certain period of time (several seconds) for stabilization, and when the pressurization equilibrium period has elapsed, a gain is given to the auto-zero reset type amplifier 41, and the differential pressure change value ΔP1, The measurement of ΔP2 is started. A curve A shown in FIG. 2 shows the amplified output of the auto-zero reset type amplifier 41.

The reset signal generator 42 supplies a zero reset signal to the auto-zero reset type amplifier 41 every time the time T1 elapses from the measurement start timing, and resets the gain of the auto-zero reset type amplifier 41 to a state of instantaneous zero. The differential pressure change values ΔP1 and ΔP2 represent the differential pressure change values immediately before the auto-zero reset type amplifier 41 is reset every time the time T1 elapses.

The differential pressure change values ΔP 1 and ΔP 2 sampled and held by the sample and hold circuit 43 are AD-converted by an AD converter 44 and input to the arithmetic and control unit 50. The arithmetic and control unit 50 can be configured by a computer system. As is well known, the computer system includes a central processing unit 51, a read-only memory 52 storing a program and the like, a rewritable memory 53 storing input data and the like, an input port 54,
And an output port 55.

In this embodiment, the rewritable memory 53 is used.
And a reset signal generator 42 and a sample and hold circuit 4 in other storage areas.
3, control means 53-2 for controlling valves 14, 16, 17 and the like
And a drift correction coefficient calculating means 5
3-3, a storage area of a drift correction coefficient storage unit 53-4, a storage area of a drift amount calculation storage unit 53-5, and a leakage amount calculation unit 53-3. 6 shows a case where a storage area for storing a program constituting -6 and a storage area for storing a program constituting a determination means 53-7 are provided.

The first aspect of the present invention proposes a method for obtaining the drift correction coefficient K from the measured values of the differential pressure change values ΔP1 and ΔP2 in the calibration mode. Claim 1
According to the drift correction coefficient calculation method proposed in the above, the drift correction coefficient K is calculated from the differential pressure change values ΔP1 and ΔP2, and K = ΔP2 / ２ΔP1 (α-1) -ΔP2} (A) We propose the calculation method to be found.

Here, α is an integer of 2 or more for setting the time for measuring the differential pressure change value ΔP2 as described above. The method of deriving this equation will be described later.
The calculation is performed in 3-3, and the calculation result is stored in the drift correction coefficient storage unit 53-4 as a calibration value. When this storage is completed, the calibration mode ends. In this calibration mode, as long as the drift correction coefficient K is stored, the calibration mode only needs to be re-calibrated when the test object changes or when the environmental condition changes greatly.

In the inspection mode, gas pressure (air pressure) is applied to the test object 20 and the reference tank 21 as in the calibration mode.
The valves 16 and 17 are controlled to be closed, a gain is applied to the auto-zero reset type amplifier 41 after the elapse of the stable period, and the differential pressure change values ΔP1 ′ and ΔP2 ′ (see FIG. 3) are measured. When the differential pressure change values ΔP1 ′ and ΔP2 ′ are obtained, the drift amount calculation storage unit 53-5 is activated, and calculates the drift amount J included in the differential pressure change value ΔP2 ′.

A third aspect of the present invention proposes a method for calculating the drift amount J. The drift amount J is obtained by reading the drift correction coefficient K stored in the drift correction coefficient storage means 53-4, and using the drift correction coefficient K and the differential pressure change values ΔP1 ′ and ΔP2 ′ measured in the inspection mode to calculate the drift amount. In −5, J = ｛ΔP1 ′ (α−1) −ΔP2 ′｝ K (B) This drift amount J is shown in FIG. This drift amount J is ΔP2 according to the value of the drift correction coefficient K.
Can be regarded as a drift amount included in the differential pressure change value ΔP2 ′ in a state where the change in the differential pressure value converges to a constant value over a long period of time.

Accordingly, by subtracting the drift amount J from the differential pressure change value ΔP2 ′ as proposed in claim 4, the differential pressure change value S corresponding to the leakage amount is obtained as S = ΔP2′-J. (C) can be calculated. This calculation is executed by the leak amount calculating means 53-6.

By calculating the differential pressure change value (drift-corrected value) S corresponding to the leakage amount, the determination means 53
-7 compares the differential pressure change value S corresponding to the leak amount with the set value SET, and sets the differential pressure change value S corresponding to the leak amount to the set value SE.
If it is larger than T, it is determined that "leakage exists". This determination result is output from the output port 55 to the outside. The example shown in FIG. 3 shows a case where it is determined that “there is leakage”. This determination method is proposed in claim 5.

In the calibration mode, the inspection object 20
This is an embodiment of the leak inspection apparatus proposed in claim 6, which uses an inspected object that has been confirmed to be free of leakage. FIG. 4 shows an embodiment of the drift correction coefficient calculation method proposed in claim 2 in which the drift correction coefficient K can be obtained even if the test object 20 has a leak. In this embodiment, in the calibration mode, the solenoid valves 16 and 17 shown in FIG. 1 are closed after gas pressure is applied to the test object 20 and the reference tank 21, and in this state, the calibration mode shown in FIG. Similarly, time T
1. While measuring the differential pressure change values ΔP1 and ΔP2 for each (α-1) T1, the state is maintained for a long time TL, and zero reset is applied again when the actual TL has elapsed for a long time ( α-1) A differential pressure change value ΔC actually generated due to leakage during T1 is measured.

By measuring the differential pressure change value ΔC generated by the leakage, in this case, the drift correction coefficient calculating means 53-3 calculates the drift correction constant K as K = (ΔP2- ΔC) / {ΔP1 (α-1) −ΔP2} (D) According to this drift correction coefficient calculation method, the component of the differential pressure change value ΔC generated by leakage is removed from the differential pressure change value ΔP2 which is a numerator in the above equation (D), so the component due to leakage is removed from the differential pressure change value ΔP2. Can be removed. Therefore, a correct drift correction coefficient K can be obtained. In the denominator, ｛ΔP1
(Α-1) -ΔP2}, the differential pressure change value ΔC due to leakage
Has been removed.

By using the drift correction coefficient calculation method proposed in claim 2, the drift correction coefficient K can be determined regardless of whether or not the test object 20 leaks in the calibration mode.
Can be requested. In the leak inspection apparatus proposed in claim 7, the drift correction coefficient calculating means 53- shown in FIG.
Reference numeral 3 denotes a configuration for calculating the drift correction constant K by the above equation (D), and the control means 53-2 includes ΔP1 and ΔP1.
In the configuration for measuring P2, a reset signal is generated when a sufficiently long time TL (generally about several tens of seconds) elapses in which a change value of the differential pressure generation of the differential pressure detector 22 is estimated to reach a constant value. , A predetermined time (α-
1) A configuration (program) for executing an operation of reading ΔC after the lapse of T1 may be added.

Time for reading differential pressure change value ΔC due to leakage
As a method of defining the TL, for example, when α = 2,
Pressure change values ΔP1, ΔP2 obtained by actual measurement of
Difference measured after the change values ΔP1 and ΔP2 were measured
Pressure change value ΔP1_n, ΔP2_n(ΔP1_n−
ΔP2_n) / (ΔP1−ΔP2) is a preset value X /
Detected that it was smaller than 100, and obtained at that time
Differential pressure change value ΔP2 _nThe differential pressure change caused by leakage
It is defined as the chemical value ΔC. X is, for example, about 3 to 5
And the ratio of the differential pressure change (ΔP1_n−ΔP
2_n) / (ΔP1−ΔP2) falls to about several%
To read ΔC or (ΔP1_n-ΔP2_n)of
The value drops below the set value (for example, about 0.03-0.05).
Configured to detect that the time TL has ended by detecting that
May be.

FIGS. 6 to 8 show claims 8 to 14 of the present invention.
Examples of a drift correction coefficient calculation method, a drift amount calculation method, a pressure change value calculation method corresponding to a leak amount, a method of determining the presence or absence of a leak, and a leak inspection apparatus to which each of these methods is applied will be described. FIG. 6 shows an embodiment of the leakage inspection apparatus proposed in claims 13 and 14 of the present invention. In this embodiment, a gas pressure is applied to the test object 20 and the test object 20
A case is shown in which the present invention is applied to a leak inspection apparatus of a type that determines whether or not there is a leak in the inspection object 20 based on a change in the gas pressure applied to the sample.

Therefore, in this embodiment, the pressure of the gas applied to the device under test 20 is measured by the pressure gauge 23, and the measured pressure value is input to the pressure change measuring means 40B. After preparing a device under test that has been confirmed to have no leakage, connect the device under test 20 to the conduit 18 and apply gas pressure as shown in FIG. Give
Each time the time T1 elapses, the pressure change values ΔQ1 and ΔQ2 are measured.

The measured values ΔQ1 and ΔQ2 are stored in the actually measured value storage 53-1 of the arithmetic and control unit 50, and the drift correction coefficient K is calculated by the drift correction coefficient calculation means 53-3 as K = ΔQ2 / ｛ΔQ1 (α− 1) -ΔQ2｝ (E) 9. A method for calculating the drift correction coefficient according to claim 8.
Propose in. According to a ninth aspect of the present invention, in the drift correction coefficient calculation method proposed in the eighth aspect, in the calibration mode, the leaky test object 20 is connected to the conduit 18 and the leaky test object 20 is connected. A method for calculating the drift correction coefficient K is proposed.

In this case, as shown in FIG. 8, when a sufficiently long time TL at which the pressure change converges to a constant value has elapsed, a reset signal is supplied to the auto-zero reset type amplifier 41. The pressure change value ΔC generated by the leakage is measured, and the drift correction coefficient K is calculated as follows: K = (ΔQ2−ΔC) / {ΔQ1 (α−1) −ΔQ2} even when the test object 20 having the leakage is used. ··· (F) The following shows an embodiment.

When the drift correction coefficient K is obtained by the drift correction coefficient calculation method proposed in claims 8 and 9, the inspection mode can be entered. FIG. 9 shows an embodiment of the inspection mode. In the inspection mode, as proposed in claim 10, the pressure change values ΔQ1 ′ and ΔQ2 ′ are measured for each of the test objects 20, and the drift amount J included in the pressure change value ΔQ2 ′ is calculated. The drift amount J is calculated by J = (ΔQ1′−ΔQ2 ′) K (G).

As shown in FIG. 9, this drift amount J takes a sufficiently long time TL (a time until the pressure of the pressure gauge 23 reaches a state in which the change converges to a constant value with the passage of time) and is stable. This corresponds to the obtained drift amount. Accordingly, as proposed in claim 11, by subtracting the drift amount J from the pressure change value ΔQ2 ′, a pressure change value S equivalent to that caused by leakage can be obtained.

By obtaining a pressure change value S equivalent to the pressure change value generated by leakage, the pressure change value S
Is compared with the set value SET, and the pressure change value S is set to the set value SE.
If it is smaller than T, it is determined that there is no leakage. This determination method is proposed in claim 12. The embodiment shown in FIG. 6 shows an embodiment of the leak inspection device proposed in claim 13, but the leak inspection device proposed in claim 14 calibrates the pressure change value ΔC corresponding to the leak proposed in claim 9. Pressure change values ΔC, ΔQ1 and Δ
The same configuration can also be realized as an embodiment of the leakage inspection device configured to obtain the drift correction coefficient K using Q2. However, a control signal generating program for obtaining ΔC and a program for obtaining ΔC are added to the control means 53-2, and K = (ΔQ2-ΔC) / ｛ΔQ1 ( α
-1) A program for calculating the drift correction coefficient K from -ΔQ2｝ may be added.

FIG. 10 shows an embodiment of a leakage inspection apparatus proposed in claim 20 of the present invention. This leak inspection device measures the differential values a1 and a2 at predetermined timings of the differential pressure value generated in the differential pressure detector 22, and calculates the drift correction coefficient K using the differential values a1 and a2. A calculation method (Claim 15), a drift amount calculation method for obtaining the drift amount J using the drift correction coefficient K obtained by the drift correction coefficient calculation method (Claim 17), and a drift amount calculation method. A leak amount calculating method for obtaining a differential value R corresponding to a leak using the drift amount J (claim 18), and a measurement comparing the differential value R corresponding to the leak calculated by the leak amount calculating method with a set value SET. A method (claim 19) is proposed.

For this reason, in the embodiment shown in FIG. 10, in the calibration mode, a leak-free test object is connected as the test object 20, and as shown in FIG. Giving a gain to the amplifier 41,
An output signal corresponding to the differential pressure detection value of the differential pressure detector 22 is output. A curve A shown in FIG. 11 shows the output of the auto zero reset type amplifier 41.

As shown in FIG. 11, the sample-and-hold circuit 43 outputs a sample-and-hold pulse every time the times TM1 and TM2 elapse from the timing 0 after the end of the pressurization equilibrium period, for example, at a time interval of about 10 ms. Given by As a result, points M1 and M2 on the curve A
In each case, the differential pressure value is taken into the sample and hold circuit 43 at a time interval of 10 ms, and the change in the differential pressure value at the time difference of 10 ms is taken into the arithmetic and control unit 50 through the AD converter 44.

The arithmetic and control unit 50 has an actual measured value storage 53-
1, control means 53-2, drift correction coefficient calculation means 53
-3, a drift correction coefficient storage unit 53-4, a drift amount calculation storage unit 53-5, a leak amount calculation unit 53-6, a determination unit 53-7, and a differential calculation unit 53-8. Means 53-8 calculate differential values a1 and a2 at points M1 and M2 on the differential pressure change curve A. The differential values a1 and a2 correspond to the values at the respective time points TM1 and TM2 on the attenuation curve B of the differential pressure change (see FIG. 11).

Therefore, assuming that there is no leakage in the test object 20, the drift correction coefficient K in this case is K = a2 / (a1-a2) (H) The derivation process of equation (H) given by will be described later. When calculating the drift correction coefficient K by calculating the differential values a1 and a2 as in this embodiment, the differential pressure change value that changes in a very short time is measured.
Any timing may be selected for M1 and TM2, as long as the measurement timings TM1 and TM2 in the inspection mode and the measurement timings TM1 and TM2 in the calibration mode are the same. Therefore, in the case of the differentiation method, the constant α for setting the measurement time is unnecessary.

When the differential calculation means 53-8 calculates the differential values a1 and a2, the drift correction coefficient calculating means 53-3 calculates the drift correction value K using the differential values a1 and a2. calculate. The calculation result is stored in the drift correction coefficient storage means 53-4. When the drift correction coefficient K is calculated and stored, the inspection mode can be executed.

In the inspection mode, as shown in FIG. 12, at the time points TM1 and TM2, the differential values a1 'and a2' at the points M1 and M2 on the differential pressure change curve A are obtained as in the calibration mode. This differential value is corrected by the drift correction coefficient K, and the drift amount J is obtained by J = (a1'-a2 ') K (I). This calculation is performed by using the drift amount calculation storage means 53-5.
Runs.

When the drift amount J is obtained, a differential value R corresponding to the leak is obtained by the leak amount calculating means 53-6.
When the differential value R is obtained, the determination means 53-7 compares the set value SET with R, and determines whether or not the test object 20 has leaked based on the magnitude relationship. In FIG. 12, R is SE
The case where SET smaller than T> R is shown. Therefore, in this case, it is determined that there is no leakage.

In the calibration mode, when it is necessary to perform the calibration using the leaked test object 20, FIG.
As shown in FIG. 3, a differential value C1 of the change in the differential pressure corresponding to the leakage is obtained by multiplying TL for a sufficiently long time, and the drift correction coefficient K is calculated using the differential value C1 as follows: K = (a2−C1) / (a1) -A2) Calculate by (J). This point is proposed in claim 16. A leak inspection apparatus having this function is proposed in claim 21.

FIG. 14 shows a method of calculating the drift correction coefficient K, a method of calculating the drift amount J proposed in claims 22 to 28,
A method for calculating a differential value R corresponding to the amount of leakage, a method for determining the presence or absence of leakage, and an example of a leakage inspection apparatus using these methods will be described. In this embodiment, a configuration is shown in which the present invention is applied to a leak inspection apparatus of a type that inspects a leak by applying a gas pressure to a single test object 20. Here, since the configuration is almost the same as that of the embodiment shown in FIG. 10, further detailed description is omitted.

FIG. 15 shows a drift correction coefficient K which varies with a temperature change in the leakage inspection device proposed in the sixth and seventh aspects.
In accordance with a temperature change.
In this embodiment, a configuration is added in which the optimum drift correction coefficient K is read out in the inspection mode and drift correction can be performed in the inspection mode. That is, the value of {ΔP1 (α-1) −ΔP2} is a value proportional to the difference between the inner wall temperature of the test object 20 and the temperature of the applied gas (air), as will be apparent from the description below. .
Therefore, the test object 20 at various temperatures in the calibration mode
Is prepared, the value of {ΔP1 (α-1) -ΔP2} is changed, and an address corresponding to the value is changed to the addressing means 5
3-9, the calculated drift correction coefficient K is stored in the generated address, and 検 査 ΔP
The configuration is such that the drift correction coefficient K is read from the address corresponding to the value of 1 '(α-1) -ΔP2'}, and the optimum drift correction coefficient K can be used.

The addressing means 53-9 outputs the measured value ΔP
1, ΔP2 or ΔQ1, ΔQ2, a1, a2, b
1, b2 {ΔP1 (α−1) −ΔP2},
{ΔQ1 (α-1) -ΔQ2}, (a1-a2), (b
1-b2) For example, means for rounding off the first decimal place and converting to an integer, or after the conversion to integers, add, subtract, multiply and divide a predetermined numerical value to be adapted to the address arrangement of the drift correction coefficient storage means 53-4. It can be constituted by means or the like.

FIG. 16 shows an example of calculation data of the drift correction coefficient K. 17 shows the drift correction coefficient calculated by each dot DOT shown in FIG. The horizontal axis X represents the differential pressure difference ｛ΔP1 (α
-1) -ΔP2｝ (α is a positive integer of 2 or more),
The vertical axis Y indicates the calculated drift correction coefficient K. A on the horizontal axis X indicates that the temperature of the test object 20 is high (for example, 80 ° C.).
, B is the value of the differential pressure difference obtained when the temperature of the device under test 20 is at room temperature (environmental temperature), and C is the value obtained when the temperature of the device under test 20 is lower than room temperature. Shows the value of the differential pressure difference.

This differential pressure difference {ΔP1 (α-1) -ΔP2}
As is clear from the change in the value with respect to the temperature, as the temperature of the test object 20 increases due to the adiabatic change of the pressurized gas, the value of the differential pressure difference {ΔP1 (α-1) −ΔP2} decreases. That is, it can be seen that the value of the differential pressure difference {ΔP1 (α-1) −ΔP2} increases as the temperature of the test object 20 approaches the normal temperature.

This phenomenon is also consistent with the differential pressure generation characteristics shown in FIG. The horizontal axis X shown in FIG. 17 represents time, and the vertical axis Y represents the differential pressure ΔP generated between the test object 20 and the reference tank 21 shown in FIG. A curve A shown in FIG. 17 indicates a differential pressure generation characteristic when the temperature of the test object 20 is normal temperature, and a curve B indicates a differential pressure generation characteristic when the temperature of the test object 20 is high (for example, 80 ° C.). . That is, the lower the temperature of the test object 20 is, the larger the difference between the temperature of the gas pressurized and sealed and the temperature of the inner wall surface of the test object 20 is. In order to stabilize the temperature, it is considered that the temperature change largely occurs, and this temperature change occurs as a large drift. This is also proved by the fact that the value of the differential pressure generated when the temperature of the test object 20 is high is small. However, in the above description, the heat capacity of the test object 20 and the reference tank 21 is relatively large, and the heat of the gas which has been pressurized and has a high temperature is transmitted to the test object 20 and the reference tank 21 over a certain period of time. Is the case.

In the case where the heat capacity of the test object 20 and the reference tank 21 is small and the heat of the gas is immediately absorbed, it is conceivable that characteristics different from those shown in FIGS. 16 and 17 are exhibited. . FIG. 16 shows that the calibration mode is executed while changing the temperature of the test object 20 having a certain heat capacity (the temperature of the reference tank 21 is kept at room temperature), and the drift correction coefficient K
The following is an example of the data obtained for. As shown in FIG. 16, if the drift correction coefficient K is obtained evenly over the entire temperature range, the difference value {ΔP1 (α-1) −ΔP2} or ｛ΔQ1 (α −
1) If -ΔQ2}, (a1-a2), and (b1-b2) are converted to integers, an address to be stored in the drift correction coefficient storage unit 53-4 can be determined. Claims 29 to 32 of the present invention propose a leak inspection apparatus equipped with an addressing means 53-9 (FIG. 15) constituted by this integer processing means.

In the thirty-third aspect, as shown in FIG. 16, the temperature of the test object 20 is changed over the entire temperature range expected to be put into practical use, and the drift correction coefficient K and the difference ｛ΔP1 (α− 1) -ΔP2｝, ｛ΔQ1 (α-1)-
ΔQ2}, (a1-a2), (b1-b2) are calculated,
The present invention proposes a drift correction coefficient learning method for determining an address from the calculated difference value and storing a drift correction coefficient K corresponding to each address.

According to the drift correction coefficient learning method proposed in claim 33, the drift correction coefficient K can be stored over a wide temperature range, and a highly practical leak inspection apparatus can be configured. By the way, in order to obtain the drift correction coefficient K over the entire practical temperature range as shown in FIG. 16, it is necessary to change the temperature of the device under test 20 to a number of temperatures. In addition, the inspection object 20
In other words, if the heat capacity or shape is different for each product type, the drift correction coefficient K must be obtained again. Therefore, it takes time and labor to obtain the data shown in FIG. 16 for each type of the test object 20.

Therefore, according to the present invention, at least two or more drift correction coefficients K1 and K2 (FIG. 18) at two or more points using test objects having different temperatures.
, K1 is the drift correction coefficient obtained for the test object at 80 ° C., K2 is the drift correction coefficient obtained for the test object at room temperature), and a drift correction coefficient exists using the plurality of drift correction coefficients. Interpolation means 5 for interpolating the drift correction coefficient by linear approximation for addresses not to be used (for example, A2 to A8 and A10 to A13 in FIG. 18)
The present invention proposes a leak inspection device provided with 3-10 (FIG. 19).

For example, when the address is A1 when the drift correction coefficient is K1 and the address is A9 when the address is K2, the drift correction coefficient K of the address A5 is K = (K1−K2) · (A9−A5) / (A9−A1)
+ K2. Therefore, according to the leakage inspection apparatus proposed in claim 34, the number of times of obtaining the drift correction coefficient K can be reduced, and a leakage inspection apparatus that is easy to handle can be provided.

FIG. 19 shows an embodiment in which the input port 54 is provided with a product type switching means 56. This kind switching means 5
When the drift correction coefficient K is taken into the drift correction coefficient storage means 53-4, the storage area is designated, and the drift correction coefficient is stored at each address of the designated storage area. Therefore, when the type of the test object 20 is predetermined, if the drift correction coefficient is stored and prepared for each type, even if the type of the test object 20 changes,
By designating and reading the storage area in which the drift correction coefficient of the type is stored, a leak test can be performed using the drift correction coefficient. A leak inspection device having a configuration to which the type switching means 56 is added is proposed in claim 35.

According to a thirty-sixth aspect of the present invention, when the drift correction coefficient K is calculated by using the test object 20 at room temperature in the calibration mode, the difference value ｛used for calculating the drift correction coefficient. ΔP1 (α-1) -ΔP
2}, {ΔQ1 (α-1) -ΔQ2}, (a1-a
2), an address determined from the values of (b1-b2) (FIG. 1)
8 corresponding to the address A9).
To zero address A0 (see FIG. 18) is equally divided to determine leak addresses A1-A9 and A9-A13.

The test object 20 in the normal temperature state
Since the address interval is defined by the address relatively far from the zero address determined by the above equation, the address can be determined by dividing the number of addresses in the drift correction coefficient storage means 53-4 by the optimal number of addresses. Is obtained.
According to a thirty-seventh aspect of the present invention, when a deviation occurs between the past drift correction coefficient stored in the drift correction coefficient storage means 53-4 and the drift correction coefficient calculated at the present time, the deviation is, for example, about 5%. In the case of the deviation in the range, the drift correction coefficients of all the addresses stored in the drift correction coefficient storage means 53-4 are corrected by the deviation, and the shift of the zero point caused by the aging of the apparatus or the like is corrected. The present invention proposes a leak inspection device to which a function of correcting the leak is added.

FIG. 20 shows this state. A curve M1 shown in FIG. 20 indicates the value of the drift correction coefficient stored in the past.
K1 (or K2) indicates the drift correction coefficient at the address B (an address generally corresponding to normal temperature) calculated by executing the calibration mode at the time when the time has elapsed (for example, about one week, one month to several months). If the correction coefficient K1 (or K2) is within the range of ± A% (for example, about 5%) from the drift correction coefficient stored at the address B of the curve M1, the curve M1 is rewritten to the curve M2 or M3. Then, it can be updated to the latest drift correction coefficient. For this purpose, as shown in FIG. 19, the arithmetic and control unit 50 may be provided with the data rewriting means 53-11 and the input port 54 may be provided with the rewriting command button 57.

However, if a large deviation of ± A% or more occurs between the past drift correction coefficient and the latest drift correction coefficient K1, K2, learning of the drift correction coefficient is performed again, and the slope of the curve M1 is reduced. It is desirable to learn and capture changes and the like. According to a thirty-eighth aspect of the present invention, in the leakage inspection apparatus including the drift correction coefficient storage means 53-4, a plurality of storage units (higher-order arrays) are provided at each address of the drift correction coefficient storage means 53-4. There is proposed a leak inspection device configured to store a drift correction coefficient value calculated in a calibration mode executed a plurality of times in a plurality of storage units.

FIG. 21 shows the drift correction coefficient storage means 5.
The inside of 3-4 is shown. Primary storage units D (1-1), D (1-2), D
(1-3)... D (1-N) is provided, and the secondary storage units D (2-1), D (2-2), D (2-3), D
(2-4)... D (2-N) are provided, and the drift correction coefficient data calculated in the calibration mode executed a plurality of times is stored in the storage unit of each array.

In the inspection mode, a plurality of drift correction coefficient values are read out by accessing each of the addresses A1 to AN.
The averaging means 53-12 shown in FIG. 2 averages the values and uses them as drift correction coefficient values when calculating the drift amount J. A leak inspection apparatus to which the averaging means 53-12 is added is claimed in claim 39.

FIG. 23 is a block diagram of the single type leak inspection apparatus shown in FIG.
0, data rewriting means 53-11, and averaging means 53-
12, a type switching means 56, and a rewrite command button 57 are added. With this configuration, the function of learning the drift correction coefficient can be added to a single type of leakage inspection device, and a leakage inspection device that is easy to handle can be provided.

FIG. 24 shows an addressing means 53-9 in a leak inspection apparatus of the type for differentiating the differential pressure change shown in FIG. 10 and obtaining the drift correction coefficient K from the differential values a1 and a2.
, Interpolation means 53-10, data rewriting means 53-11
The configuration of a leakage inspection apparatus to which an averaging unit 53-12, a type switching unit 56, and a rewrite command button 57 are added is shown.
FIG. 25 shows the single type leak inspection apparatus shown in FIG. 14 with the addressing processing means 53-9, the interpolation means 53-10, the data rewriting means 53-11, the averaging means 53-12, and the kind switching means 56. And an embodiment in which a rewrite command button 57 is provided.

It can be easily understood from the above description that the leak inspection devices shown in FIGS. 23 to 25 also provide the same operation and effects as those of the leak inspection devices shown in FIGS. 19 and 22. Also, in the above description, FIGS.
As shown in FIGS. 5, 7, 8, and 9, the differential pressure change value Δ
P1, ΔP2 and the pressure change values ΔQ1, ΔQ2 have been described at intervals of time T1, but as shown in FIG.
An arbitrary length of time TX between the period of measuring 1 and ΔP2
May be present. The reason will be described later.

From the above description, the embodiments corresponding to each claim of the present invention can be understood. In the following, whether the drift correction coefficient K is obtained by K = ΔP2 / (ΔP1−ΔP2) when α = 2 in the leakage inspection apparatus shown in FIG. 1 and the differential values a1 and
a2 will be described, and it will be described whether the drift correction coefficient K can be obtained by K = a2 / (a1−a2) based on these differential values a1 and a2.

First, will be described. State change of pressurized gas In a differential pressure type leak tester, when performing a leak test at a certain gas pressure, a change in differential pressure may occur at the time of detection, even if there is no leakage or deformation of the test object. is there.

As the pressure difference and the stabilization time become shorter, the change in the differential pressure and the variation in the data tend to increase. This phenomenon is related to the inspection pressure, the material and the shape of the test object, and essentially depends on the physical properties of the gas, that is, the process by which the change in the gas temperature due to the so-called Joule-Thomson effect stabilizes with time. According to Newton's law of cooling, "if there is a gas having a temperature θ ° (average temperature) in the surface temperature Θ ° of the body to be inspected, the amount of heat dq that the gas obtains in the short time dt is the minute time dt and the temperature difference. (Θ-θ) ”(Newton's law of cooling).

Assuming that the calorific value dq is obtained and the gas temperature rises by dθ, Cdθ = dq (C: heat capacity of gas) dq
Is proportional to dt and the temperature difference (Θ−θ). · · (1) h: It is related to the proportionality constant, the surface area inside the work, the shape and the dimensions.

K: It is a proportionality constant but related to the shape, material, and dimensions including the heat capacity of gas. Since the same gas transmits energy from the equation (1), the k value changes when the gas temperature changes.
However, here, for simplicity, k is a constant (since k can be regarded as constant at normal temperature).

Here, assuming that the temperature difference is approximately small, k
Is not dependent on the temperature, dθ / (Θ−θ) = kdt (2) When the expression (2) is integrated, 1n (Θ−θ) = − kt + C1 When t = 0, θ = θ ₀ Since the integration constant C1 is C1 = 1n (Θ-θ ₀ ), よ り −θ = (Θ−θ ₀ ) e− ^kt (3) Since PV / θ = R according to Boyle-Charles' law, P = (R / V) [Θ- (Θ-θ ₀ ) e ^-kt ] (4) Since the change in the body pressure to be inspected can be expressed by the differential of equation (4), dP / dt = ｛Rk (Θ-θ) ₀ ) / V｝ e- ^kt (5) Equation (5) is an equation that expresses the pressure in the body to be inspected by differentiation. When there is a leak in the body to be inspected, the pressure change dP /
If dt = C ₀ and Rk (Θ−θ ₀ ) / V = A, equation (5) becomes dP / dt = Ae− ^kt + C ₀ (6) where A =） Rk (Θ−θ ₀ )｝ / V Drift correction method when differential pressure change is detected by differential change When gas pressure is applied to the test object, the gas temperature rises (Joule-Thomson effect), and the differential formula of the internal pressure is It is expressed by an expression including an attenuation term.

Next, let us consider what kind of drift correction should be performed on the difference between the differential pressures (the differential pressure change value at the detection time T1). If equation (6) is expressed in the form of integral, T
The change in differential pressure after one hour is ΔP _T1 = (A / k) (1−e− ^kT1 ) + C ₀ T1 (7) After ^2T1 hour, ΔP _2T1 = (A / k) (1−e− ^2kT1 ) ) + 2C ₀ T1 (8) If equation (7) is the differential pressure change ΔP1 in detection 1,
Equation (8) is the sum of the differential pressure change ΔP1 of detection 1 and the differential pressure change ΔP2 of detection 2. If A / k = B, (7),
(8) is ^{B (1-e -kT1) +} C 0 T1 = ΔP1 ··· (9) B (1-e -2kT1) + 2C 0 T1 = ΔP1 + ΔP2 ··· (10) 2 × (9) - ( From (10), B (1-2e− ^kT1 + e− ^2kT1 ) = ΔP1−ΔP2 (11) The parentheses in the equation (11) are constants, and when this is α1, the equation (11) is Bα1 = ΔP1 −ΔP2 (12) If C ₀ = 0 and equation (9) is substituted into equation (10), B (e ^−kT1 −e ^−2kT1 ) = ΔP2 (13) (13) The parentheses in the parentheses are also constants, and if this is set to α2, the expression (13) becomes Bα2 = ΔP2 (14) From the expressions (12) and (14), ΔP2 / (ΔP1-ΔP2) = α2 / α1 = E ^-kT1 (1-e ^-kT1 ) / (1-2e ^-kT1 + e ^-2kT1 ) = K (15)

As can be seen from the equation (12), the coefficient B is a function proportional to the difference between the inner surface temperature of the test object and the gas temperature, and therefore ΔP1−ΔP2 includes a term proportional to the temperature difference. ing. Further, as can be understood from the above calculation example, under the condition that the pressure change due to leakage per unit time (T1) is constant, the differential pressures ΔP1 and ΔP2 at the respective unit times (T1) are different from each other at different time intervals. Can also define the drift correction coefficient K.

The following is a description. Consider two points where the measurement time of the differential pressure change is different (FIGS. 11 to 13).
1, the differential value of the pressure change after TM2 hours from (6) ^{_{dP TM1 / dt = Ae -kTM1 +}} Co = a1 ··· (16) dP TM2 / dt = Ae -kTM2 + Co = a2 ··· (17 From (16)-(17), A (e ^−kTM1 −e ^−kTM2 ) = a1−a2 (18) The parentheses in the expression (18) are constants, and if this is ^replaced by β1, (18) The equation is Aβ1 = a1−a2 (19) When Co = 0, from equation (17), Ae− ^kTM2 = a2 (20) e− ^kTM2 is also a constant. Okeba (2
Equation (0) is Aβ2 = a2 (21) From equations (19) and (21), a2 / (a1-a2) = β2 / β1 = e− ^kTM2 / (e− ^kTM1− e− ^kTM2 ) = K · ··· (22) If the measured values a1 ′ and a2 ′ are obtained from equation (22), the correction amount J is J = K (a1′−a2 ′) (23) Therefore, the drift correction result R is R = a2 '-J (24) As is clear from the above description, the differential pressure change values ΔP1 and ΔP2 described with reference to FIGS. 1 to 3 are measured, the drift correction coefficient K is set to α = 2, and K = ΔP2 / (ΔP1-ΔP2)
And the differential value a described in FIGS.
1, a2 is measured and the drift correction coefficient K is calculated as K = a2 /
It can be understood that drift correction can be appropriately performed also in the case of (a1-a2). In addition, when the drift correction coefficient K is obtained for a leaky test object, K = (ΔP2−
ΔC) / (ΔP1-ΔP2), K = (a2-C1) /
It can also be easily understood that (a1-a2) can be expressed.

Next, the case where α is a general formula of 2 or more will be described. Time T1 in detection 1 (measurement of ΔP1)
Then, when the time of the detection 2 (measurement of ΔP2) is αT1, what kind of drift correction should be performed is examined (here, α is an integer of 2 or more). ΔP _T1 = A / k (1−e− ^kT1 ) + C ₀ T1 (25) After α × T1 hour

[0116]

(Equation 1) If the equation (25) is the differential pressure change ΔP1 in the detection 1,
Equation (26) is the sum of the differential pressure change ΔP1 of detection 1 and the differential pressure change ΔP2 of detection 2. If A / k = B, (2
Equations (5) and (26) are as follows: B (1−e ^−kT1 ) + C ₀ T1 = ΔP1 (27)

[0117]

(Equation 2) From α × (27)-(28)

[0118]

(Equation 3) When there is no leakage, equations (27) and (28) are

[0119]

(Equation 4) From equations (29) and (30)

[0120]

(Equation 5) K in equation (31) can be regarded as a constant as long as k, T1, and α do not change. K is called a drift correction coefficient. Equation (31) can be written as the following equation.

ΔP2 = K [ΔP1 (α-1) -ΔP2] (32) Expression (32) is an expression for obtaining the lift component in detection 2. Generally, when the differential pressure change of the detection 1 is ΔPa and the differential pressure change of the detection 2 is ΔPb, the drift component Pc of the detection 2
Is given by equation (31): ΔPc = K [ΔPa (α−1) −ΔPb] (33) Equation (33) is the drift component ΔPc in each detection 2
Therefore, if the differential pressure in the detection 2 is ΔPx, the differential pressure change ΔP due to leakage is ΔP = ΔPx−ΔPc (34) Expressions (33) and (34) using the drift correction coefficient K In the method of correcting the drift by using the data, the correction amount is directly obtained because the drift amount is obtained by using the data of the detection 1 and the detection 2 each time. Further, since the correction coefficient K is not so affected by the work temperature, it is possible to perform room temperature drift correction (within a change range of room temperature).

Next, an arbitrary time TX between the detection 1 and the detection 2
Analyze the case where is inserted. The differential pressure ΔP _T1 generated in the detection 1 and the differential pressure value ΔP generated after T1 + TX time
ΔP _{TK +} α _T1 can express the differential pressure value generated after _{T1 + TX} and time T1 + TX + (α−1) T1 as follows. ΔP _T1 = A / k (1−e− ^kT1 ) + C ₀ T1 (35) ΔP _{T1 + TX} = A / k (1−e− ^{k (T1 + TX)} ) + C ₀ (T1 + TX) (36)

[0123]

(Equation 6) Let A / k = B From equations (36) and (37)

[0124]

(Equation 7) From equation (35), B (1−e− ^kT1 ) × (α−1) + C ₀ T1 (α−1) = ΔP1 × (α−1) (39) From (39) − (38)

[0125]

(Equation 8) When there is no leakage from equations (38) and (40)

[0126]

(Equation 9) Equation (41) is a constant as long as k, T1, TX, and α (an integer of 2 or more) do not change. As described above, the drift correction coefficient can be obtained even when the time interval between the detection 1 and the detection 2 is set to an arbitrary time TX.

FIG. 27 shows an experimental result for verifying the effect of the present invention. In the experimental results shown in FIG. 27, the drift correction coefficient was obtained when air was applied by changing the pressurization equilibrium time to 5 seconds, 6 seconds, 7 seconds, and 8 seconds in a state where the leak-free test object was connected to the reference tank. Investigating how the value of K shows a tendency to change, and measuring at other pressurization times using the drift correction coefficient K obtained at a specific pressurization time (6 seconds in the figure) When drift correction is performed on the actually measured values ΔP1 and ΔP2, the drift correction value S becomes the true value (pressurization time 6
2 shows an error from the drift correction value S obtained in seconds.

That is, in this example, ΔP1 and ΔP2 are actually measured a plurality of times (five times) at each pressurization time as α = 2, (ΔP1−ΔP2) is calculated from the measured values, and ΔP1 is calculated for each measured value. -ΔP2 and the drift correction coefficient K are obtained, and ΔP
The drift correction value S was calculated from 1, ΔP2 and (ΔP1−ΔP2) K. In FIG. 27, ΔP2 and (ΔP1−Δ
P2) and the average value of the drift correction value K is calculated, and drift correction is performed using the average value of the correction coefficient K obtained in the reference pressurization time (6 seconds) of 1.21 using these average values. Is shown.

The drift correction result S = -0.4 calculated with the pressurization time of 5 seconds is ΔP2 = 5.3, ΔP1-ΔP2 = 4.7, and the drift correction coefficient K = 1.21, S = 5.3-4. .7 × 1.21
= −0.4. Also, S = 0.3 for 7 seconds is S = 3.
It was calculated according to 2-2.5 × 1.21 = 0.3. S = 0 for 8 seconds.
3 was calculated according to S = 2.7−2.0 × 1.21 = 0.3. 1.1 calculated in the column of the prior art is an actually measured value ΔP2 = 4 obtained when a pressurization time of 6 seconds defined as a reference is taken from ΔP2 = 5.3 actually measured at a pressurization time of 5 seconds. 5.3 minus 2
Calculated as 5.2 = 1.1. -0.9 of the prior art calculated when the pressurization time was 7 seconds was determined by 3.3-4.2 = -0.9.
-1.5 calculated with a pressurization time of 8 seconds was determined as 2.7-4.2 = -1.5.

It can be understood from this experimental result that the drift correction result S is +1.1 to −1.
5 and the error is large. On the other hand, when the drift correction coefficient K proposed by the present invention is used, the drift correction value S changes between -0.4 and 0.3, and the amount of change is small. As a result, it is understood that a large error does not occur even if the inspection mode is executed using the drift correction coefficient K obtained under the condition that the pressurization time is different.

FIG. 28 shows an experiment in which the tendency of the change of the value of the drift correction coefficient K and the tendency of the change of the drift correction result S obtained when a temperature difference is provided between the test object and the reference tank are obtained. Here is an example. In FIG. 28, M indicates the temperature of the reference tank, and W indicates the temperature of the test object. In this experiment, ΔP when both the temperature of the reference tank and the temperature of the test object were 10 ° C.
When the average value of Δ2, the average value of ΔP1−ΔP2, and the average value K of the drift correction coefficient K = 1.21 are defined as the reference, the actually measured values ΔP1 and ΔP2 measured under other temperature conditions are used as the drift correction coefficient. It shows an error value of the drift correction result S when drift correction is performed using K = 1.21. When the drift correction coefficient K according to the present invention is used, the drift correction value S becomes S
= 0 to 0.5 (mmH ₂ O), and it can be seen that the error is small.

On the other hand, in the conventional technique, S is S = 0 to-
It can be seen that it varies between 2.5 (mmH ₂ O) and is larger than the error of the present invention. FIG. 29 shows the results of an experiment on how the value of the drift correction coefficient K changes when the gas pressure (test pressure) applied to the test object and the reference tank changes.
In this case, the drift correction coefficient K = 1.
32, the drift correction coefficient S is used to calculate the error of the drift correction result S generated when the ΔP1 and ΔP2 measured at other test pressures are drift corrected. When the drift correction coefficient K = 1.32 is used, S = −
It can be seen that the value varies between 0.4 and 0.3 (mmH ₂ O), and the error is small even if the test pressure is changed.

S = −1.4 obtained by the prior art is ΔP1 =
This is a value obtained by subtracting ΔP1 = 4.8 from 3.4. Also, S =
0.8 is a value obtained by subtracting ΔP1 = 4.8 from ΔP1 = 5.6.

[0134]

As described above, according to the present invention, even if the drift correction coefficient K obtained in the calibration mode under a certain condition is used for a leak test under another condition, the drift correction coefficient K can be accurately calculated without causing a large error. Drift correction (drift amount can be removed). In addition, the drift correction coefficient is calculated based on the differential pressure difference corresponding to the temperature difference between the temperature of the test object and the gas, and the calculated drift correction coefficient is stored. In the inspection mode, the drift correction coefficient is calculated based on the differential pressure difference corresponding to the temperature difference. Since the coefficient is read and the inspection is performed using the optimum drift correction coefficient, a correct inspection can always be performed.

As a result, there is obtained an advantage that it is possible to provide a leak inspection apparatus which is practically easy to handle.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a drift correction coefficient calculation method and a leakage inspection device proposed in claims 1 to 7 of the present invention.

FIG. 2 is a graph for explaining an operation in a calibration mode of FIG. 1;

FIG. 3 is a graph for explaining the operation in the inspection mode in FIG. 1;

FIG. 4 is a graph for explaining another calibration mode in FIG. 1;

FIG. 5 is a graph for explaining another example of the calibration mode.

FIG. 6 is a block diagram for explaining an embodiment of a drift correction coefficient calculation method and a leak inspection apparatus proposed in claims 8 to 14 of the present invention.

FIG. 7 is a graph for explaining an operation in a calibration mode of the embodiment shown in FIG. 6;

FIG. 8 is a graph for explaining an operation in another calibration mode in FIG. 6;

FIG. 9 is a graph for explaining the operation in the inspection mode in FIG. 6;

FIG. 10 is a block diagram for explaining an embodiment of a drift correction coefficient calculating means and a leakage inspection device proposed in claims 15 to 21 of the present invention.

FIG. 11 is a graph for explaining the operation in the calibration mode of the embodiment shown in FIG. 10;

FIG. 12 is a graph for explaining an operation in the inspection mode of the embodiment shown in FIG. 10;

13 is a graph for explaining another operation of the calibration mode of the embodiment shown in FIG.

FIG. 14 is a block diagram for explaining an embodiment of a drift correction coefficient calculation method and a leakage inspection device proposed in claims 22 to 28 of the present invention.

FIG. 15 is a block diagram for explaining an embodiment of a leakage inspection device proposed in claim 29 of the present invention.

FIG. 16 is a graph for explaining a drift correction coefficient learning method according to the present invention.

FIG. 17 is a graph for explaining the tendency of the arrangement of the drift correction coefficients shown in FIG. 16;

FIG. 18 is a graph for explaining another example of the drift correction coefficient learning method of the present invention.

FIG. 19 is a block diagram for explaining another embodiment of the leakage inspection device proposed in claims 34 and 37 of the present invention.

FIG. 20 is a graph for explaining the operation of the leakage inspection device proposed in claim 37 of the present invention.

FIG. 21 is a view for explaining a configuration of a main part of the leakage inspection apparatus claimed in claim 38;

FIG. 22 is a block diagram for explaining an embodiment of a leakage inspection device proposed in claim 29 of the present invention.

FIG. 23 is a block diagram for explaining an embodiment of a leakage inspection device proposed in claim 30 of the present invention.

FIG. 24 is a block diagram for explaining an embodiment of a leakage inspection device proposed in claim 31 of the present invention.

FIG. 25 is a block diagram for explaining an embodiment of a leakage inspection device proposed in claim 32 of the present invention.

FIG. 26 is a graph showing another example of the measurement timing of the leakage inspection device of the present invention.

FIG. 27 is a diagram showing experimental results for explaining the operation and effect of the present invention.

FIG. 28 is a view similar to FIG. 27;

FIG. 29 is a view similar to FIG. 27;

FIG. 30 is a block diagram for explaining a conventional leak inspection device.

FIG. 31 is a graph for explaining the operation of the leakage inspection device shown in FIG. 30;

FIG. 32 is a graph for explaining an operation in a conventional calibration mode.

FIG. 33 is a block diagram for explaining another structure of a conventional leakage inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pneumatic pressure source 12 Pressure regulator 13 Pressure gauge 14 Three-way solenoid valve 15A, 15B Branch pipe 16, 17 Solenoid valve 18, 19 Conduit 20 Inspection object 21 Reference tank 22 Differential pressure detector 23 Pressure gauge 40A Differential pressure change measurement Means 40B Pressure change measuring means 40C Differential pressure differentiating means 40D Pressure differentiating means 41 Auto zero reset type amplifier 42 Reset signal generator 43 Sample hold circuit 44 A / D converter 50 Arithmetic controller 51 Central processing unit 52 Read only memory 53 Rewritable Memory 54 Input port 55 Output port 53-1 Measured value storage 53-2 Control means 53-3 Drift correction coefficient calculation means 53-4 Drift correction coefficient storage means 53-5 Drift amount calculation storage means 53-6 Leakage amount calculation means 53-7 Judgment means K Drift correction coefficient J Drift amount S Drift corrected value R Drift corrected value 53-8 Differential operation means 53-9 Addressing processing means 53-10 Interpolation means 53-11 Data rewriting means 53-12 Averaging means 56 Type switching means 57 Rewriting command button

Claims (39)

[Claims] 1. A method according to claim 1, wherein a positive or negative gas pressure is applied to an object to be inspected and a reference tank, and when a predetermined time has elapsed, a difference in pressure between the two is greater than or equal to a predetermined value. In the calibration mode of the leak inspection device for determining whether or not there is a leak, a leak-free inspection object is mounted on the mounting portion of the inspection object, and positive or negative is applied to the leak-free inspection object and the reference tank. Pressure difference between the test object and the reference tank every time the time T1 and (α-1) T1 (α is a positive integer of 2 or more) elapse from the end of pressurization equilibrium. The change values ΔP1 and ΔP2 are actually measured, and the differential pressure change values ΔP1 and ΔP2 are measured.
2, the drift correction coefficient K is calculated as K = ΔP2 / ｛ΔP1 (α
-1) A drift correction coefficient calculation method used for a leak inspection calculated by -ΔP2}. 2. The method according to claim 1, wherein a positive or negative gas pressure is applied to the test object and the reference tank, and a predetermined pressure or more is generated between the test object and the reference tank. In the calibration mode of the leak inspection apparatus for determining whether or not there is a leak, the leaked test object is mounted on the mounting portion of the test object, and the leaked test object and the reference tank are positively or negatively mounted. The pressure difference ΔP1 and ΔP2 generated between the test object and the reference tank each time the time T1 and (α-1) T1 elapse from the end of the pressurization equilibrium are measured, When the change in the differential pressure generated between the test object and the reference tank is stabilized, a differential pressure change value ΔC corresponding to the leakage of the test object obtained in (α-1) T1 time is measured,
The drift correction coefficient K is calculated from these differential pressure change values ΔP1, ΔP2, and ΔC as K = (ΔP2-ΔC) / ｛ΔP1 (α
-1) A drift correction coefficient calculation method used for a leak inspection calculated by -ΔP2}. 3. A positive or negative gas pressure is applied to the test object and the reference tank, and a time T1 from the end of pressurization equilibrium of the gas pressure.
And (α-1) T1, the differential pressure change values ΔP1 ′ and ΔP2 ′ generated between the test object and the reference tank every time T1 elapses.
And the actually measured differential pressure change values ΔP1 ′ and ΔP2
'And the drift correction coefficient K calculated in claim 1 or 2
Wherein the drift amount J included in the differential pressure change value ΔP2 ′ is calculated by J = ｛ΔP1 ′ (α−1) −ΔP2 ′｝ K. 4. A method in which a positive or negative gas pressure is applied to an object to be inspected and a reference tank, and when a predetermined time elapses, whether or not a differential pressure equal to or more than a predetermined value is generated between the two is determined. In the leak inspection method for determining whether or not there is a leak, the drift amount J calculated in claim 3 is subtracted from the actually measured differential pressure change value ΔP2 ′ by S = ΔP2′−J to deal with the leak. A drift correction method for obtaining a differential pressure change value S after drift correction. 5. The method according to claim 4, wherein the differential pressure change value S calculated in claim 4 is compared with a set value to determine whether or not the test object is leaked based on whether the differential pressure change value S is larger or smaller than the set value. Characteristic leak inspection method. 6. A. A. a pneumatic source for applying a positive or negative gas pressure to the test object and the reference tank; B. differential pressure measuring means for applying a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank and measuring a differential pressure change value generated between the test object and the reference tank after the application is completed; In the calibration mode, a leak-free test object is connected to the connection portion of the test object, a gas pressure is applied to the leak-free test object and the reference tank, and a time T1 and ( α-1) Each time T1 elapses, the differential pressure change values ΔP1 and ΔP2 measured by the differential pressure measuring means are fetched,
D. a drift correction coefficient calculating means for calculating a drift correction coefficient K from the differential pressure change values ΔP1 and ΔP2 by K = ΔP2 / {ΔP1 (α-1) -ΔP2}; D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied to the object to be inspected and the reference tank from the air pressure source, and after the pressurization equilibrium, the differential pressure change value ΔP1 ′, ΔP2 ′ is measured, and a drift amount J included in the differential pressure change value ΔP2 ′ is calculated from the differential pressure change values ΔP1 ′ and ΔP2 ′ by J = (ΔP1′−ΔP2 ′) K. Differential pressure change value S = ΔP2′−J obtained by dividing from pressure change value ΔP2 ′ and drift corrected.
D. drift correction means calculated by A differential pressure change value S drift-corrected by the drift correction means is compared with a set value, and when the differential pressure change value S exceeds the set value, the determination means determines that the test object is leaking. A leak inspection device characterized by the following. 7. A. A. a pneumatic source for applying a positive or negative gas pressure to the test object and the reference tank; A differential pressure measuring means for applying a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank, and measuring a differential pressure change value generated between the test object and the reference tank after the pressurization equilibrium, C. In the calibration mode, a leaking test object is connected to the connection portion of the test object, a gas pressure is applied to the leaking test object and the reference tank, and a time T1 and ( α-1) Changes in differential pressure generated between the test object and the reference tank from the end of application of the differential pressure change values ΔP1 and ΔP2 and the gas pressure measured by the differential pressure measuring means each time T1 elapses. At the time when the pressure becomes stable, the differential pressure change value ΔC generated at the time (α-1) T1 is taken, and the drift correction coefficient K is calculated by the differential pressure change values ΔP1, ΔP2, and ΔC.
D. a drift correction coefficient calculating means calculated by: = (ΔP2-ΔC) / {ΔP1 (α-1) -ΔP2}; D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation and storage means; In the inspection mode, a gas pressure is applied to the object to be inspected and the reference tank from an air pressure source, and after the completion of the pressurization equilibrium, each time the time T1 and (α-1) T1 elapse, the pressure difference is measured by the pressure difference measuring means. The change values ΔP1 ′ and ΔP2 ′ are actually measured, and the differential pressure change values ΔP2 ′ are calculated from the differential pressure change values ΔP1 ′ and ΔP2 ′.
Is the drift amount J included in the equation: J = ｛ΔP1 ′ (α−1) −
ΔP2 ′｝ K, the drift amount J is divided by the differential pressure change value ΔP2 ′, and the drift-corrected differential pressure change value S is calculated.
D. a drift correction means that calculates S = ΔP2′-J. A differential pressure change value S drift-corrected by the drift correction means is compared with a set value, and when the differential pressure change value S exceeds the set value, it is determined that the test object is leaking. A leak inspection device characterized by the following. 8. A device according to claim 7, wherein a positive or negative gas pressure is applied to the device under test, and a leak to the device under test depends on whether the gas pressure applied to the device under test changes at a predetermined time. In the calibration mode of the leak inspection device for determining whether or not there is a leak test device, a leak-free test object is mounted on the mounting portion of the test object, and a positive or negative gas pressure is applied to the leak-free test object. , Time T1 from the end of pressurization equilibrium and (α-1) T1
Each time the pressure change values ΔQ1 and ΔQ2 of the gas pressure applied to the test object are measured, the pressure change values ΔQ1
From ΔQ2 and the drift correction coefficient K, K = ΔQ2 / ｛ΔQ
1 (α-1) -ΔQ2} A drift correction coefficient calculation method used for a leak inspection calculated by: 9. The test object is leaked depending on whether a positive or negative gas pressure is applied to the test object and the gas pressure applied to the test object changes after a predetermined time has elapsed. In the calibration mode of the leakage inspection device for determining whether or not the leakage inspection device is mounted on the leakage inspection device, the gas pressure is applied to the leakage inspection device, and the pressurization equilibrium is completed. Every time the time T1 and (α-1) T1 elapse from the time point, the pressure change value ΔQ1 of the gas pressure applied to the test object.
And ΔQ2, and when the pressure change of the gas pressure applied to the test object becomes stable, the pressure change value ΔC generated at time (α-1) T1 due to leakage of the test object is measured. The drift correction coefficient K is calculated from the pressure change values ΔQ1, ΔQ2, and ΔC as follows: K = (ΔQ2−ΔC) /
A drift correction coefficient calculation method used for leakage inspection calculated by {ΔQ1 (α-1) -ΔQ2}. 10. A positive or negative gas pressure is applied to the test object, and a time T1 and (α−
1) Each time T1 elapses, the pressure change values ΔQ1 ′ and ΔQ2 ′ of the gas pressure applied to the test object are actually measured, and the actually measured pressure change values ΔQ1 ′ and ΔQ2 ′ and calculated by claim 8 or 9 The drift amount J included in the pressure change value ΔQ2 ′ is calculated by the following drift correction coefficient K as J = ｛ΔQ1 ′.
(Α-1) -ΔQ2 ′｝ K, wherein the drift amount is calculated. 11. A positive or negative gas pressure is applied to a test object, and when a predetermined time has elapsed, the gas pressure applied to the test object generates a differential pressure equal to or more than a predetermined value, and In the leak inspection method for determining whether or not the inspection object has a leak, the drift amount J calculated in claim 10 is subtracted from the actually measured pressure change value ΔQ2 ′ to obtain a drift corrected pressure change value. A drift correction method, wherein S is obtained by S = ΔQ2′-J. 12. The pressure change value S calculated in claim 11 is compared with a set value, and the pressure change value S is larger than the set value.
A leak inspection method characterized in that it is determined whether or not the inspection object has leaked depending on whether the leak is small. 13. A. B. a pneumatic source for applying a positive or negative gas pressure to the test object; B. pressure measuring means for measuring a change in gas pressure applied to the test object; In the calibration mode, a leak-free test object is connected to the connection portion of the test object, a gas pressure is applied to the leak-free test object, and a time T1 and (α
-1) The pressure change values ΔQ1 and ΔQ2 measured by the pressure measuring means are fetched every time T1 elapses, and the drift correction coefficient K is calculated by the pressure change values ΔQ1 and ΔQ2 as K = ΔQ
D / Drift correction coefficient calculation means calculated by {ΔQ1 (α-1) -ΔQ2}; D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied from the pneumatic source to the object to be inspected, and after the pressurization equilibrium, the pressure change value ΔQ1 ′ is obtained by the pressure measuring means at a time interval equal to the time T1 and (α-1) T1. , ΔQ2 ′, and from the pressure change values ΔQ1 ′, ΔQ2 ′, the drift amount J included in the pressure change value ΔQ2 ′ is calculated as J = ｛ΔQ1 ′ (α−1) −ΔQ
2 ′｝ K, and calculate the drift amount J as the pressure change value Δ
The pressure change value S that has been drift-corrected by dividing from Q2 '
D. a drift correction means calculated by ΔQ2′-J; The pressure change value S drift-corrected by the drift correction means is compared with a set value, and when the pressure change value S exceeds the set value, the determination means determines that the test object is leaking. A leak inspection device characterized by the above-mentioned. 14. A. B. a pneumatic source for applying a positive or negative gas pressure to the test object; B. pressure measuring means for measuring a change in gas pressure applied to the test object; In the calibration mode, a leaking test object is connected to the connection portion of the test object, a gas pressure is applied to the leaking test object, and the time T1 and (α− 1) The pressure change values ΔQ1 ′, ΔQ2 ′ measured by the pressure measuring means each time T1 elapses and the time when the pressure change of the gas pressure applied to the test object after the application of the gas pressure is stabilized. The pressure change value ΔC due to the leak generated at the time (α-1) T1 is taken in, and the drift correction coefficient K is calculated by these pressure change values ΔQ1, ΔQ2 and ΔC as K = (ΔQ2-ΔC) / ｛ΔQ1 (α-1) −ΔQ
D. a drift correction coefficient calculating means for calculating by 2｝; D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied from the pneumatic source to the object to be inspected, and after the pressurization equilibrium, the pressure change value ΔQ1 ′ is obtained by the pressure measuring means at a time interval equal to the time T1 and (α-1) T1. , ΔQ2 ′, and from the pressure change values ΔQ1 ′, ΔQ2 ′, the drift amount J included in the pressure change value ΔQ2 ′ is calculated as J = ｛ΔQ1 ′ (α−1) −ΔQ
2 ′｝ K, and calculate the drift amount J as the pressure change value Δ
The pressure change value S that has been drift-corrected by dividing from Q2 '
D. a drift correction means calculated by ΔQ2′-J; The pressure change value S drift-corrected by the drift correction means is compared with a set value, and when the pressure change value S exceeds the set value, the determination means determines that the test object is leaking. A leak inspection device characterized by the above-mentioned. 15. Applying a positive or negative gas pressure to an object to be inspected and a reference tank, and determining whether a differential pressure equal to or more than a predetermined value is generated between the two after a predetermined time has elapsed. In the calibration mode of the leak inspection device for determining whether or not there is a leak, a leak-free inspection object is mounted on the mounting portion of the inspection object, and positive or negative is applied to the leak-free inspection object and the reference tank. Is applied for a predetermined time T from the end of pressurization equilibrium.
The differential values a1 and a2 of the differential pressure change at each timing when M1 and TM2 elapse are measured, and the drift correction coefficient K is calculated from the differential values a1 and a2 as K = a2 /
A drift correction coefficient calculation method used for a leak inspection calculated by (a1-a2). 16. A method for applying a positive or negative gas pressure to an object to be inspected and a reference tank, and determining whether or not a differential pressure equal to or more than a predetermined value is generated between the two after a lapse of a predetermined time. In the calibration mode of the leak inspection apparatus for determining whether or not there is a leak, the leaked test object is mounted on the mounting portion of the test object, and the leaked test object and the reference tank are positive or negative. The differential pressures a1 and a2 of the differential pressure change at each timing when the predetermined time TM1 and TM2 elapse from the end of pressurization and the differential pressure change converges within a predetermined numerical value range at each time when the predetermined time TM1 and TM2 elapse Differential value C at the time
1, and the drift correction coefficient K is calculated as K = (a2−C1) / (a1−a) using the differential values a1, a2, and C1.
A drift correction coefficient calculation method used in the leak inspection calculated in 2). 17. A positive or negative gas pressure is applied to the test object and the reference tank, and the test object and the reference tank are connected each time a predetermined time TM1, TM2 elapses from the end of the application of the gas pressure. Differential value a1 of differential pressure change occurring between
', A2', and the differential value a of the actually measured differential pressure change.
The drift amount J included in the differential value a2 ′ is calculated by J = (a1′−a2 ′) K using 1 ′, a2 ′ and the drift correction coefficient K calculated in claim 15 or 16. Drift amount calculation method. 18. A method in which a positive or negative gas pressure is applied to an object to be inspected and a reference tank, and when a predetermined time elapses, whether or not a differential pressure equal to or more than a predetermined value is generated between the two, determines whether the object is to be inspected. 18. A leak inspection method for determining whether or not there is a leak in a differential pressure change obtained by subtracting from a differential value a2 'of a differential pressure change obtained by actually measuring the drift amount J calculated in claim 17 to obtain a drift-corrected differential pressure change. A drift correction method, wherein the value R is obtained by R = a2'-J. 19. A differential value R of the differential pressure change calculated in claim 18 is compared with a set value, and it is determined whether or not the inspection object has leaked based on whether the differential value R of the differential pressure change is larger or smaller than the set value. Leak inspection method characterized by performing. 20. A. A. a pneumatic source for applying a positive or negative gas pressure to the test object and the reference tank; A differential pressure differential for applying a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank and measuring differential values a1 and a2 of a differential pressure change generated between the test object and the reference tank after the application is completed. Means; In the calibration mode, a leak-free test object is connected to the connection portion of the test object, gas pressure is applied to the leak-free test object and the reference tank, and a predetermined time is elapsed from the end of pressurization equilibrium of the gas pressure. The differential values a1 and a2 measured by the differential pressure differentiating means are taken in at each timing when TM1 and TM2 elapse, and the drift correction coefficient K is calculated as K = a2 / (a1-a2) by the differential values a1 and a2 of the differential pressure change. D. a drift correction coefficient calculating means for calculating D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied to the object to be inspected and the reference tank from the pneumatic source, and the differential pressure differentiating means is used by the differential pressure differentiating means every time the predetermined times TM1 and TM2 elapse after the pressurization equilibrium is completed. Differential value of change a1 ', a
2 ′ is actually measured, and from the differential values a1 ′ and a2 ′, the drift amount J included in the differential value a2 ′ of the differential pressure change is calculated as J = (a1 ′).
-A2 ') drift correction means for calculating the differential value R of the differential pressure change obtained by dividing the drift amount J from the differential value Δa2' of the differential pressure change by R = a2'-J. F. The differential value R of the differential pressure change drift-corrected by the drift correction means is compared with a set value, and when the differential value R of the differential pressure change exceeds the set value, a determining means for determining that there is a leak in the test object. And a leak inspection device. 21. A. A. a pneumatic source for applying a positive or negative gas pressure to the test object and the reference tank; A differential pressure differential for applying a gas of a predetermined pressure from the pneumatic source to the test object and the reference tank and measuring differential values a1 and a2 of a differential pressure change generated between the test object and the reference tank after the application is completed. Means; In the calibration mode, a leaking test object is connected to the connection portion of the test object, a gas pressure is applied to the leaking test object and the reference tank, and a predetermined time from the end of pressurization equilibrium of the gas pressure. Differential value a1, of the differential pressure change measured by the differential pressure differentiating means at each timing when TM1 and TM2 elapse.
a2 and the differential value C1 of the differential pressure change generated when the change in the differential pressure generated between the test object and the reference tank is stabilized after the application of the gas pressure is completed, and the differential value a1 of the differential pressure change is obtained. D. a, a2, C1 to calculate a drift correction coefficient K by K = (a2-C1) / (a1-a2); D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied to the object to be inspected and the reference tank from the pneumatic source, and the differential pressure differentiating means is used by the differential pressure differentiating means every time the predetermined times TM1 and TM2 elapse after the completion of the pressurization equilibrium. Differential value of change a1 ', a
2 ′ is actually measured, and from the differential values a1 ′ and a2 ′, the drift amount J included in the differential value a2 ′ of the differential pressure change is calculated as J = (a1 ′).
-A2 ') drift correction means for calculating the differential value R of the differential pressure change obtained by dividing the drift amount J from the differential value Δa2' of the differential pressure change by R = a2'-J. F. The differential value R of the differential pressure change drift-corrected by the drift correction means is compared with a set value, and when the differential value R of the differential pressure change exceeds the set value, it is determined that the test object is leaked. Means for inspecting leakage. 22. A positive or negative gas pressure is applied to the test object, and leakage of the test object depends on whether or not the gas pressure applied to the test object changes after a predetermined time has elapsed. In the calibration mode of the leak inspection device for determining whether or not there is a leak-proof device, a leak-free test object is mounted on the mounting portion of the test object, and a leak is detected on the leak-free test object on the mount portion of the test object. The test object without leak is attached, and a positive or negative gas pressure is applied to the test object without leak, and the test object is applied to the test object every time when a predetermined time TM1, TM2 elapses from the end of pressurization equilibrium. Differential value b of pressure change of applied gas pressure
1 and b2, a drift correction coefficient K is calculated from the differential values b1 and b2 of the pressure change by K = b2 / (b1-b2) and stored. 23. A positive or negative gas pressure is applied to the test object, and leakage of the test object depends on whether or not the gas pressure applied to the test object changes after a predetermined time has elapsed. In the calibration mode of the leak inspection device for determining whether or not there is a leak test device, the leak test device is mounted on the mounting portion of the test device, gas pressure is applied to the leak test device, and the pressurizing equilibrium is applied. At each time when predetermined times TM1 and TM2 elapse from the end point, differential values b1 and b2 of the pressure change of the gas pressure applied to the test object and differential values at the timing when the pressure change converges within a predetermined numerical value range. C1 is measured, and the drift correction coefficient K is calculated based on these differential values b1, b2, and C1.
= (B2−C1) / (b1−b2) is calculated and stored. 24. A positive or negative gas pressure is applied to the test object, and a predetermined time TM1,
Each time the TM2 elapses, the differential values b1 'and b2' of the change in the gas pressure applied to the test object are measured, and the drift amount J is determined by the differential values b1 'and b2'.
= (B1′−b2 ′) K, wherein the drift amount is calculated. 25. A method in which a positive or negative gas pressure is applied to an object to be inspected, and the gas pressure applied to the object to be inspected at a point in time when a predetermined time elapses is determined by whether or not a differential pressure equal to or more than a predetermined value is generated. A leak inspection method for determining whether a leak exists in an object to be inspected, wherein the drift amount J calculated in claim 24 is subtracted from a differential value b2 'of the pressure change obtained by actual measurement to obtain a drift corrected pressure change. Wherein the differential value R is obtained by R = b2'-J. 26. A differential value R of the pressure change calculated in claim 25 is compared with a set value, and it is determined whether or not the inspection object has leaked based on whether the differential value R of the pressure change is larger or smaller than the set value. A leak inspection method, characterized in that: 27. A. B. a pneumatic source for applying a positive or negative gas pressure to the test object; B. pressure differentiating means for measuring a differential value of a change in pressure obtained by differentiating a change in gas pressure applied to the test object; In the calibration mode, a leak-free test object is connected to the connection portion of the test object, a gas pressure is applied to the leak-free test object, and predetermined times TM1 and TM2 are set from the end of pressurization equilibrium of the gas pressure. D. a drift correction coefficient calculating means for calculating a drift correction coefficient K by K = b2 / (b1−b2) based on differential values b1 and b2 of the pressure change measured by the pressure differentiating means at each time when the pressure elapses. D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied to the inspection object from the pneumatic source, and a predetermined time T
At each timing when M1 and TM2 elapse, the differential values b1 'and b2' of the pressure change are actually measured by the pressure differentiating means,
From the differential values b1 'and b2' of the pressure change, the drift amount J included in the differential value b2 'of the pressure change is calculated as J = (b1'-b
D ′) a drift correction means for calculating the differential value R of the pressure change obtained by dividing the drift amount J from the differential value b2 ′ of the pressure change and calculating the differential value R of the pressure change by R = b2′−J. Comparing the differential value R of the pressure change drift-corrected by the drift correction means with a set value, and determining that the object to be inspected is leaked when the differential value R of the pressure change exceeds the set value; And a leakage inspection device. 28. A. B. a pneumatic source for applying a positive or negative gas pressure to the test object; B. pressure differentiating means for measuring a differential value of a change in gas pressure applied to the test object; In the calibration mode, a leaking test object is connected to the connection portion of the test object, a gas pressure is applied to the leak-free test object, and predetermined times TM1 and TM2 are set from the end of pressurization equilibrium of the gas pressure. The differential value b1, b2 of the pressure change measured by the pressure differentiating means at each timing when the pressure elapses and the pressure change of the gas pressure applied to the test object from the end of the application of the gas pressure are within a predetermined numerical range. The differential value C1 of the pressure change at the time of the convergence is taken in, and the drift correction coefficient K is calculated by K = (b2-C1) / (b1-b2) using the differential values b1, b2, and C1 of the pressure change, and stored. D. a drift correction coefficient calculating means; D. drift correction coefficient storage means for storing the drift correction coefficient calculated by the drift correction coefficient calculation means; In the inspection mode, a gas pressure is applied to the inspection object from the pneumatic source, and a predetermined time T
At each timing when M1 and TM2 elapse, the differential values b1 'and b2' of the pressure change are actually measured by the pressure differentiating means,
From the differential values b1 'and b2' of the pressure change, the drift amount J included in the differential value b2 'of the pressure change is calculated as J = (b1'-b
D ′) a drift correction means for calculating the differential value R of the pressure change obtained by dividing the drift amount J from the differential value b2 ′ of the pressure change and calculating the differential value R of the pressure change by R = b2′−J. Comparing the differential value R of the pressure change drift-corrected by the drift correction means with a set value, and determining that the object to be inspected is leaked when the differential value R of the pressure change exceeds the set value; And a leakage inspection device. 29. The leak inspection apparatus according to claim 6, wherein the temperature of the inner wall surface of the test object and the test object are determined from the differential pressure change values ΔP1 and ΔP2 measured by the differential pressure measuring means. A value {ΔP1 (α-1) −ΔP2} proportional to the difference between the temperature of the gas pressurized and applied and
The calculated value is converted into an address signal by the address signal processing means, and the drift correction coefficient storage means is accessed by the address signal to obtain the differential pressure change values ΔP1 and ΔP2.
A drift correction coefficient K obtained from the data stored in the memory at an address accessed by the address signal. 30. The leak inspection device according to claim 13, wherein the temperature change on the inner wall surface of the inspection object and the temperature change on the inspection object are obtained from the pressure change values Q1 and Q2 measured by the pressure measuring means. Calculate a value {ΔQ1 (α-1) −ΔQ2} proportional to the difference between the temperature of the pressurized and applied gas,
The calculated value is converted into an address signal by the address signal processing means, and the drift correction coefficient storage means is accessed by the address signal, and the pressure change values ΔQ1 and ΔQ2
A drift correction coefficient K obtained from the data stored in the memory at an address accessed by the address signal. 31. The leak inspection apparatus according to claim 20, wherein the temperature of the inner wall surface of the object to be inspected and the temperature of the inner wall surface of the object to be inspected are obtained from the differential values a1, a2 of the differential pressure change measured by the differential pressure differentiating means. A value (a1-a2) proportional to the difference between the temperature of the gas pressurized and applied to the test object is calculated, and the calculated value is converted into an address signal by an address signal processing means, and the drift is performed by the address signal. A leak inspection apparatus comprising accessing a correction coefficient storage means and storing a drift correction coefficient K obtained from the differential values a1 and a2 of the differential pressure change at an address accessed by the address signal. 32. The leak inspection apparatus according to claim 27, wherein the temperature of the inner wall surface of the test object and the differential value b1, b2 of the pressure change measured by the pressure differentiating means are used. A value (b1-b2) proportional to the difference between the temperature of the pressurized gas and the applied gas is calculated, and the calculated value is converted into an address signal by an address signal processing unit.
A leak inspection apparatus, wherein the drift correction coefficient storage means is accessed by the address signal, and the drift correction coefficient K obtained from the differential values b1 and b2 of the pressure change is stored at the address accessed by the address signal. 33. In any one of the calibration modes of the leak inspection apparatus according to claim 29, a plurality of test objects having different surface temperatures are prepared, and the test objects having different surface temperatures are sequentially mounted on the mounting portion. And the value {ΔP1 (α-1) −ΔP2} or｝ ΔQ1 for each test object having a different temperature.
(Α-1) -ΔQ2｝, (a1-a2), (b1-b
2) A method of learning a drift correction coefficient of a leakage inspection apparatus, wherein the method of (2) is dispersed and the drift correction coefficient is stored in a plurality of addresses prepared in the drift correction coefficient storage means. 34. A leak inspection apparatus in which a drift correction coefficient is stored at a plurality of addresses of the drift correction coefficient storage means by the drift correction coefficient learning method according to claim 33, wherein the drift correction coefficient is stored at the plurality of addresses. A method for interpolating and storing the drift coefficient by linear approximation even at an address where the storage of the drift correction coefficient does not exist. 35. A leak inspection apparatus in which a drift correction coefficient is stored by the drift correction coefficient learning method according to claim 33, wherein the drift correction coefficient storage means stores a plurality of storage areas corresponding to the type of the device to be inspected. A leak inspection apparatus that selects one of the plurality of storage areas according to the type of the object to be inspected and writes and reads a drift correction coefficient. 36. The drift correction coefficient learning method according to claim 33, wherein the temperature of the test object is a normal temperature, and a value of an address signal generated by a measurement value obtained from the test object at the normal temperature is used as a reference. And an address to be assigned to the drift correction coefficient storage means. 37. A leakage inspection apparatus in which a drift correction coefficient is stored by any one of the drift correction coefficient learning methods according to claim 33, wherein a calibration mode is executed, and a drift correction coefficient obtained in the calibration mode is obtained. If the deviation between the value and the value of the drift correction coefficient stored at the address obtained in the calibration mode deviates within a predetermined range, the drift correction coefficient stored in each address of the drift correction coefficient storage means is adjusted. A leak inspection device wherein the value of a coefficient is corrected by the same amount as the deviation. 38. A leakage inspection apparatus in which a drift correction coefficient is stored in a drift correction storage unit by the drift correction coefficient learning method according to claim 33, wherein a plurality of storage units are provided at each address of the drift correction coefficient storage unit. A leak inspection apparatus characterized in that a drift correction coefficient calculated with the same address value can be stored in a plurality of storage units. 39. The leakage inspection apparatus according to claim 38, further comprising averaging means for calculating an average value of the plurality of drift correction coefficients read from the same address, and calculating the average of the drift correction coefficients averaged by the averaging means. A leak inspection device that performs a leak inspection using.