JP2010066168A - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

An ultrasonic inspection apparatus and an ultrasonic inspection method capable of accurately determining whether or not a contact medium is supplied to a position between an ultrasonic sensor and an object to be inspected are provided.
A contact medium supply mechanism for supplying a contact medium to a surface to be inspected of an object to be inspected in an ultrasonic inspection apparatus and an ultrasonic wave directed toward the object to be inspected through the contact medium. An ultrasonic sensor 141 for detecting the intensity of the transmitted and received ultrasonic wave, and an ultrasonic sensor 141 based on the value of the higher-order coefficient of the third-order or higher order function approximating the ultrasonic intensity-reception time graph; A contact medium determination unit 151d for determining whether or not the contact medium 5 is supplied to a position sandwiched between the inspection object 1 and the inspection object 1;
[Selection] Figure 1

Description

The present invention relates to a technique for inspecting the internal quality of an inspection object using ultrasonic waves.
More specifically, the present invention relates to a technique for determining whether or not a contact medium is supplied to a position sandwiched between an ultrasonic sensor that generates ultrasonic waves and an object to be inspected.

Conventionally, an ultrasonic inspection apparatus that uses ultrasonic waves to inspect the internal quality of an inspection object, for example, whether there is a crack inside the inspection object, whether there is a foreign object inside the inspection object, etc. It is publicly known.
Such an ultrasonic inspection apparatus generally transmits an ultrasonic wave toward an object to be inspected and outputs an ultrasonic signal that outputs an intensity signal corresponding to the received intensity of the ultrasonic wave reflected by the object to be inspected. And a determination device for determining whether or not there is a foreign substance inside the inspection object based on a signal output from the ultrasonic sensor.

In addition, such an ultrasonic inspection apparatus interposes an ultrasonic wave transmitted from the ultrasonic sensor to the inspection object by interposing a contact medium such as water or glycerin at a position sandwiched between the ultrasonic sensor and the inspection object. Make it incident efficiently (without much attenuation).
The following methods (1) and (2) are known as a method of interposing a contact medium at a position between the ultrasonic sensor and the object to be inspected.

The method (1) is a method in which a contact medium and a test object are accommodated in a container (water tank or the like), and the test is performed in a state where the test object is immersed in the contact medium.
The method (1) is excellent in that the contact medium can be reliably interposed (supplied) at a position between the ultrasonic sensor and the inspection object.
However, the method (1) requires an operation of immersing the inspection object in a container in which the contact medium is accommodated (stored) and an operation of taking out the inspection object after the inspection. If the product is an article that has a weight that is difficult to carry in, it is necessary to have a device for mechanizing these operations, which increases the size and complexity of the device as a whole. Have.

The method (2) is a method of performing inspection while supplying the contact medium continuously to a position sandwiched between the ultrasonic sensor and the object to be inspected, for example, by discharging the contact medium from the tip of the nozzle.
As an apparatus to which the method (2) is applied, for example, an ultrasonic flaw detection apparatus described in Patent Document 1 is known.
The method (2) has an advantage that the apparatus can be easily simplified and miniaturized because the work for immersing the test object in the container containing the contact medium and the work for taking out the test object after the test are not required.
However, since the method (2) supplies a contact medium as a fluid to a position sandwiched between the ultrasonic sensor and the object to be inspected, the ultrasonic sensor and the object to be inspected depend on the shape, orientation, and other apparatus configurations of the object to be inspected. In some cases, the contact medium cannot be supplied well to the position sandwiched between the inspection objects.
In general, the intensity (reception intensity) of the ultrasonic wave received by the ultrasonic sensor varies depending on whether or not the contact medium is interposed between the ultrasonic sensor and the object to be inspected (no contact medium is interposed). In this case, the reception strength is reduced).
Therefore, the method (2) has a problem that the reliability of the inspection result is low unless it is confirmed that the contact medium is present at the position between the ultrasonic sensor and the inspection object.

  As apparatuses for solving the problem of the method (2), apparatuses described in Patent Document 2 and Patent Document 3 are known.

In the automatic ultrasonic flaw detector described in Patent Document 2, the rise time of the ultrasonic wave (boundary echo) reflected from the boundary surface between the inspection object and the contact medium (the ultrasonic wave transmitted from the ultrasonic sensor is incident on the contact medium) The thickness of the contact medium is reflected by the property that the time taken for the light to be reflected by the interface between the object to be inspected and the contact medium and received by the ultrasonic sensor is approximately proportional to the thickness of the contact medium. presume.
Further, the automatic ultrasonic flaw detector described in Patent Document 2 experimentally obtains a relationship between the thickness of the contact medium and the reception sensitivity of the ultrasonic sensor in advance, and calculates the relationship and the estimated thickness of the contact medium. The received intensity of the ultrasonic wave received by the ultrasonic sensor is corrected.
However, the automatic ultrasonic flaw detector described in Patent Document 2 will eventually end up if the relationship between the thickness of the contact medium experimentally obtained and the reception sensitivity of the ultrasonic sensor is not highly reliable (reproducibility). There is a problem that it is difficult to increase the reliability of the inspection result.

The ultrasonic test apparatus described in Patent Document 3 is a position that is sandwiched between an ultrasonic sensor and an object to be inspected when the intensity (sound pressure) of the ultrasonic wave received by the ultrasonic sensor is equal to or greater than a preset threshold value. Is located between the ultrasonic sensor and the object to be inspected when it is determined that a contact medium is present in the sensor and the intensity (sound pressure) of the ultrasonic wave received by the ultrasonic sensor is less than a preset threshold value. It is determined that no contact medium is present in
However, it is difficult for the ultrasonic testing apparatus described in Patent Document 3 to set an ultrasonic threshold value for determining whether or not a contact medium is interposed at a position between the ultrasonic sensor and the inspection object. Have the problem of being.

Of the ultrasonic waves detected by the ultrasonic sensor, the ultrasonic wave reflected by the contact medium is considered to have a short time (reception time) from when the ultrasonic sensor transmits the ultrasonic wave to when it is received.
Qualitatively, when the intensity of the ultrasonic wave with a short reception time is relatively large, it is considered that the contact medium is interposed between the ultrasonic sensor and the inspection object, and the reception time is short. When the intensity of the ultrasonic wave is relatively small, it is considered that the contact medium is not interposed at the position between the ultrasonic sensor and the inspection object.
Therefore, when the influence of noise from the outside is not taken into consideration, as shown in FIGS. 4A and 4B, the maximum value of the intensity of the ultrasonic wave in a predetermined determination section having a short reception time is equal to or greater than a predetermined threshold. The ultrasonic test apparatus can determine whether or not a contact medium is present at a position between the ultrasonic sensor and the object to be inspected.

However, as shown in FIG. 4C, in actual inspection, external noise is superimposed on the ultrasonic wave detected by the ultrasonic sensor, and among the ultrasonic waves detected by the ultrasonic sensor, the reception time is short. The strength may increase temporarily. In such a case, the peak value of the intensity (voltage) of the ultrasonic wave due to noise may be greater than or equal to a preset threshold value.
In the case shown in (c) of FIG. 4, the ultrasonic sensor is actually used even though the inspection is performed in a state where the contact medium is not interposed at the position between the ultrasonic sensor and the inspection object. It is erroneously determined that the inspection is performed in a state where the contact medium is interposed at the position between the inspection object.
If the inspection is performed in the state where the contact medium is not interposed between the ultrasonic sensor and the object to be inspected, the intensity of the ultrasonic wave that seems to be reflected from the inside of the object to be inspected from the reception time Therefore, it may cause a situation in which it is erroneously determined that there is no defect in spite of the fact that there is a defect, or that the size of the defect is erroneously determined to be smaller than the actual size.
In this way, it is determined whether or not a contact medium is present at a position between the ultrasonic sensor and the object to be inspected based only on the intensity of the ultrasonic wave detected by the ultrasonic sensor but having a short reception time. In this method, it is difficult to improve the reliability of the inspection result, and as a result, it becomes an obstacle to automating the inspection (for example, a contact medium is interposed between the ultrasonic sensor and the inspection object). A large number of inspection objects are inspected in the absence of any of these inspection objects. May cause a situation such as judgment).
JP 2000-298120 A JP 63-198885 A JP 2006-234770 A

  The present invention has been made in view of the above situation, and an ultrasonic inspection capable of accurately determining whether a contact medium is supplied to a position sandwiched between an ultrasonic sensor and an object to be inspected. An apparatus and an ultrasonic inspection method are provided.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in claim 1,
A contact medium supply unit for supplying a contact medium to the surface to be inspected of the object to be inspected;
An ultrasonic sensor that transmits ultrasonic waves to the inspection object through the contact medium, receives ultrasonic waves reflected by the inspection object and the contact medium, and detects the intensity of the received ultrasonic waves; ,
Third order or higher order approximation of a graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor and the time from when the ultrasonic sensor transmits the ultrasonic wave until it receives the reflected ultrasonic wave. A contact medium that generates a function and determines whether or not the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the object to be inspected based on a value of a second or higher order coefficient of the higher-order function A determination unit;
It comprises.

In claim 2,
The contact medium determination unit includes:
When the absolute value of the quadratic or higher coefficient of the higher order function is equal to or greater than a preset value, it is determined that the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object. And
When the absolute value of the second or higher order coefficient of the higher order function is less than a preset value, it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object To do.

In claim 3,
When the contact medium determination unit determines that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object, an alarm generation unit that issues an alarm is provided.

In claim 4,
A moving unit configured to relatively move the ultrasonic sensor along a surface to be inspected of the inspection object;

In claim 5,
The moving unit is
While maintaining the relative positions of the contact medium discharge port and the ultrasonic sensor in the contact medium supply unit, the contact medium discharge port and the ultrasonic sensor in the contact medium supply unit are placed on the object to be inspected. The relative movement is made along the inspection surface.

In claim 6,
The moving unit is
When the contact medium determination unit determines that the contact medium is not supplied at a position between the ultrasonic sensor and the inspection object, the relative movement of the ultrasonic sensor is stopped.

In claim 7,
In a state where the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object, the ultrasonic sensor transmits an ultrasonic wave toward the inspection object through the contact medium, and the inspection object An ultrasonic transmission / reception step of receiving an ultrasonic wave reflected by an object and the contact medium, and detecting an intensity of the received ultrasonic wave;
Ultrasound that generates a graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor and the time from the transmission of the ultrasonic wave to the reception of the reflected ultrasonic wave in the ultrasonic wave transmission / reception step Strength-reception time graph generation process;
A third order or higher order function approximating the graph generated in the ultrasonic intensity-reception time graph generation step is generated, and the ultrasonic sensor and the object to be measured are generated based on the value of the second order or higher coefficient of the higher order function. A contact medium determination step of determining whether or not the contact medium is supplied to a position sandwiched between the inspection object;
It comprises.

In claim 8,
In the contact medium determination step,
When the absolute value of the quadratic or higher coefficient of the higher order function is equal to or greater than a preset value, it is determined that the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object. And
When the absolute value of the second or higher order coefficient of the higher order function is less than a preset value, it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object To do.

In claim 9,
In the contact medium determination step, an alarm generation step for generating an alarm when it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object is provided.

In claim 10,
A moving step of relatively moving the ultrasonic sensor along the inspection surface of the inspection object;

In claim 11,
In the contact medium determination step, when it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the object to be inspected, relative movement of the ultrasonic sensor and the ultrasonic sensor and the object to be inspected An emergency stop step of stopping the supply of the contact medium to a position sandwiched between objects.

  The present invention has an effect that it is possible to accurately determine whether or not the contact medium is supplied to a position between the ultrasonic sensor and the inspection object.

  Below, the ultrasonic inspection apparatus 100 which is one Embodiment of the ultrasonic inspection apparatus which concerns on this invention using FIG. 1 is demonstrated.

The ultrasonic inspection apparatus 100 is an apparatus that inspects the quality of the inspection object 1.
“Inspection object” refers to an article to be inspected by an ultrasonic inspection apparatus. Specific examples of the inspection object include die-cast products, welded parts of articles in which a plurality of parts are joined by welding, semiconductor ingots, and the like.
“Inspecting the quality of an object to be inspected” includes determining whether or not there is a defect (such as a crack, a foreign object, or a cavity) inside the object to be inspected.
The shape of the inspection object 1 of this embodiment is a rectangular parallelepiped shape, and the upper surface thereof becomes the inspection surface 1a.
The “inspected surface of the inspection object” refers to the surface of the surface of the inspection object on which the ultrasonic wave transmitted from the ultrasonic sensor is incident.
The shape of the object to be inspected according to the present invention is not limited to the rectangular parallelepiped shape as in this embodiment, but from the viewpoint of improving the reliability of the inspection result by the ultrasonic inspection apparatus according to the present invention, The inspection surface is desirably smooth, and it is desirable that the inspection be performed in a state where the distance from the ultrasonic sensor to the inspection surface of the inspection object is kept constant.

  As shown in FIG. 1, the ultrasonic inspection apparatus 100 mainly includes an inspection table 110, a moving mechanism 120, a contact medium supply mechanism 130, an ultrasonic sensor unit 140, and an inspection unit 150.

The inspection table 110 is a table on which the inspection object 1 is placed at a predetermined position in a predetermined posture.
The inspection table 110 according to the present embodiment is a rectangular plate-like member, and is placed on the ground or floor. The upper surface of the inspection table 110 (the surface on which the inspection object 1 is mounted) placed on the ground or floor is parallel to the horizontal plane (the surface perpendicular to the direction in which gravity acts).

The moving mechanism 120 is an embodiment of a moving unit according to the present invention, and relatively moves an ultrasonic sensor 141 (to be described later) along the surface to be inspected 1.
The moving mechanism 120 includes a frame 121, a rail 122, a ball screw 123, a slide block 124, a motor 125, and a movement control device 126.

  The frame 121 is a member constituting the main structure of the moving mechanism 120. The frame 121 includes columns 121a and 121a and beams 121b that connect the upper ends of the columns 121a and 121a that are erected from two corners of the inspection table 110, respectively.

  The rail 122 is a long bar-like member and is disposed above the inspection table 110. Both ends of the rail 122 are fixed to the frame 121.

The ball screw 123 is a round bar-like member having a male screw formed on the outer peripheral surface over its entire length.
The ball screw 123 is arranged such that its axial direction is parallel to the longitudinal direction of the rail 122. Both ends of the ball screw 123 are rotatably supported by the frame 122.

  The slide block 124 is a member that slides in the longitudinal direction of the rail 122 while engaging with the rail 122. The slide block 124 is screwed into the ball screw 123.

The motor 125 is a drive source that rotationally drives the ball screw 123. The motor 125 of the present embodiment is an electric motor (for example, a servo motor, a stepping motor, etc.) that can control the rotation amount (rotation angle).
When the motor 125 is energized, the ball screw 123 is rotationally driven, and the slide block 124 screwed with the ball screw 123 slides along the rail 122.

  The movement control device 126 is a device that controls the operation of the motor 125 and thus the operation of the moving mechanism 120. The movement control device 126 stores a program related to the operation of the movement mechanism 120. The movement control device 126 according to the present embodiment includes a programmable logic controller (PLC).

The contact medium supply mechanism 130 is an embodiment of the contact medium supply unit according to the present invention, and supplies the contact medium 5 to the upper surface of the inspection object 1.
A “contact medium” is a medium (a substance or object that is a field through which waves propagate) that transmits ultrasonic waves transmitted from an ultrasonic sensor to an object to be inspected, and usually has a fluidity (liquid or gel). Material). Specific examples of the contact medium include water, oil, glycerin, water glass (sodium silicate aqueous solution), and the like.
The contact medium supply mechanism 130 mainly includes a tank 131, a first transfer pipe 132, a pump 133, a second transfer pipe 134, and a nozzle 135.

The tank 131 is a container that accommodates the contact medium 5.
The first transport pipe 132 is a pipe for taking out and transporting the contact medium 5 accommodated in the tank 131, and one end thereof is inserted into the tank 131.
The pump 133 sucks the contact medium 5 accommodated in the tank 131 and discharges it by applying pressure. The pump 133 has two ports, a suction port and a discharge port, sucks the contact medium 5 from the suction port, and discharges the sucked contact medium 5 from the discharge port. The suction port of the pump 133 is connected to the other end of the first transfer pipe 132.
The second transfer pipe 134 is a pipe for transferring the contact medium 5 discharged from the pump 133, and one end thereof is connected to the discharge port of the pump 133. The second transfer pipe 134 of the present embodiment is made of a bendable material (for example, rubber, resin, etc.).
The nozzle 135 is a cylindrical member that forms a discharge port for the contact medium 5 in the contact medium supply mechanism 130, and is connected to the other end of the second transport pipe 134. The nozzle 135 is fixed to the slide block 124 of the moving mechanism 120 and moves integrally with the slide block 124.

  By operating the pump 133 of the contact medium supply mechanism 130, the contact medium 5 accommodated in the tank 131 is pumped to the nozzle 135 through the first transport pipe 132, the pump 133 and the second transport pipe 134, and discharged from the nozzle 135. Is done. The contact medium 5 discharged from the nozzle 135 is poured onto the inspection surface 1 a of the inspection object 1.

  The ultrasonic sensor unit 140 includes an ultrasonic sensor 141, an ultrasonic transmitter 142, and an ultrasonic receiver 143.

The ultrasonic sensor 141 is an embodiment of the ultrasonic sensor according to the present invention. The ultrasonic sensor 141 transmits an ultrasonic wave toward the inspection object 1 through the contact medium 5 and is reflected by the inspection object 1 and the contact medium 5. The ultrasonic wave is received and the intensity of the received ultrasonic wave is detected.
The ultrasonic sensor 141 according to the present embodiment includes a vibrator having a unimorph structure, that is, a vibrator in which a metal plate is bonded to piezoelectric ceramic and a pair of electrodes is provided.

The ultrasonic transmitter 142 is a device that applies a voltage having a predetermined frequency to the vibrator of the ultrasonic sensor 141. The ultrasonic transmitter 142 is connected to a pair of electrodes provided on the vibrator of the ultrasonic sensor 141.
When the ultrasonic transmitter 142 applies a voltage having a predetermined frequency to the transducer of the ultrasonic sensor 141, the transducer is bent at the same frequency as the voltage applied by the ultrasonic transmitter 142, and the transducer is ultrasonic. An ultrasonic wave having the same frequency as the frequency of the voltage applied by the transmitter 142 is transmitted.

  When the transducer of the ultrasonic sensor 141 receives an ultrasonic wave from the outside, it has the same frequency as the frequency of the received ultrasonic wave, and the intensity (sound pressure) of the ultrasonic wave received by the transducer of the ultrasonic sensor 141. An electrical signal having a voltage proportional to is generated. The electric signal corresponds to information related to the intensity of the ultrasonic wave detected by the ultrasonic sensor 141.

  The ultrasonic receiver 143 is an apparatus that receives an electrical signal generated by the transducer of the ultrasonic sensor 141 and converts the received signal into an electrical signal that can be received by the unit main body 151 described later. The ultrasonic receiver 143 is connected to a pair of electrodes provided on the transducer of the ultrasonic sensor 141. The electric signal converted by the ultrasonic receiver 143 also corresponds to information related to the intensity of the ultrasonic wave detected by the ultrasonic sensor 141.

The ultrasonic sensor 141 is fixed to the slide block 124 and transmits an ultrasonic wave toward the inspection object 1 placed on the inspection table 110 (in the present embodiment, obliquely downward).
The longitudinal direction of the inspection surface 1a of the inspection object 1 placed on the inspection table 110 and the rail 122 are both parallel to the horizontal plane, so that the ultrasonic sensor 141 even if the slide block 124 moves along the rail 122. The distance from the lower end portion of the inspection object 1 to the inspection surface 1a of the inspection object 1 is kept constant.

The contact medium 5 poured onto the inspection surface 1a of the inspection object 1 by the contact medium supply mechanism 130 is supplied between the ultrasonic sensor 141 and the inspection surface 1a of the inspection object 1, and the ultrasonic sensor 141. And the surface 1a to be inspected 1 are filled with the contact medium 5.
Therefore, the ultrasonic wave transmitted from the ultrasonic sensor 141 is incident on the inspection object 1 through the contact medium 5.
In addition, an ultrasonic wave (reflected wave) reflected by a defect inside the inspection object 1 or the contact medium 5 is transmitted to the ultrasonic sensor 141 via the contact medium 5 and received by the ultrasonic sensor 141.

In this embodiment, since the nozzle 135 (the discharge port of the contact medium 5 in the contact medium supply mechanism 130) and the ultrasonic sensor 141 are both fixed to the slide block 124, the relative positions of the nozzle 135 and the ultrasonic sensor 141 are relative to each other. The slide block 124 moves in a state where is held.
Further, the nozzle 135 is fixed to the slide block 124 with its tip (discharge port of the contact medium 5) being directed to a position sandwiched between the ultrasonic sensor 141 and the surface to be inspected 1a of the object 1 to be inspected. Even if the slide block 124 moves (even if the relative position of the ultrasonic sensor 141 with respect to the inspection object 1 changes), the contact medium 5 is sandwiched between the ultrasonic sensor 141 and the inspection surface 1a of the inspection object 1. Stable supply to the position.

  The inspection unit 150 includes a unit main body 151, an input device 152, and a display device 153.

  The unit main body 151 can store various programs and the like, can develop these programs and the like, can perform predetermined calculations according to these programs and the like, and can store the results of the calculations and the like. The result of the calculation can be output to the outside.

The unit main body 151 has a configuration in which a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and the like are connected to each other via a bus. Alternatively, a configuration including a one-chip LSI (Large Scale Integration) or the like may be used.
The unit main body 151 in this embodiment is a dedicated product, but it can also be achieved by appropriately storing a program or the like in a commercially available personal computer or workstation.

  The unit main body 151 is connected to the movement control device 126. The unit main body 151 can transmit a signal for instructing the operation of the moving mechanism 120 (movement of the slide block 124) and its stop to the movement control device 126.

  The unit main body 151 is connected to the pump 133. The unit main body 151 can transmit a signal for instructing the operation of the pump 133 (pressure feeding of the contact medium 5) and the stop thereof to the pump 133.

  The unit main body 151 is connected to the ultrasonic transmitter 142. The unit main body 151 can transmit a signal for instructing the operation of the ultrasonic transmitter 142 (application of a voltage of a predetermined frequency to the transducer of the ultrasonic sensor 141) and the stop thereof to the ultrasonic transmitter 142. is there.

  The unit main body 151 is connected to the ultrasonic receiver 143. The unit main body 151 can acquire the electrical signal converted by the ultrasonic receiver 143.

The input device 152 inputs various information / instructions related to the inspection of the inspection object 1 by the ultrasonic inspection apparatus 100 to the unit main body 151 and is connected to the unit main body 151.
Although the input device 152 of this embodiment is a dedicated product, for example, a commercially available keyboard, mouse, pointing device, button, switch, or the like may be used.

The display device 153 displays the input content from the input device 152 to the unit main body 151, the operation status of the ultrasonic inspection apparatus 100, and the like, and is connected to the unit main body 151.
Although the display device 153 of the present embodiment is a dedicated product, for example, a commercially available liquid crystal display (LCD; Liquid Crystal Display), a CRT display (Cathode Ray Tube Display), or the like may be used.

Below, the detail of a structure of the unit main body 151 is demonstrated.
The unit main body 151 functionally includes a storage unit 151a, an operation control unit 151b, a defect determination unit 151c, and a contact medium determination unit 151d.

The storage unit 151a includes various parameters (numerical values) used for operations performed by the operation control unit 151b, the defect determination unit 151c, and the contact medium determination unit 151d, the history of the operation status of the ultrasonic inspection apparatus 100, and the inspection performed by the ultrasonic inspection apparatus 100. The result is stored.
The storage unit 151a is essentially a storage medium such as an HDD, RAM, ROM, CD-ROM, or DVD-ROM.

The operation control unit 151b controls a series of operations performed by the ultrasonic inspection apparatus 100.
Substantially, the unit main body 151 performs a predetermined calculation or the like according to the operation control program stored in the unit main body 151, thereby serving as the operation control unit 151b.

  The operation control unit 151b transmits a signal indicating that the pump 133 operates. The pump 133 that has received the signal pumps the contact medium 5. As a result, the contact medium 5 is discharged from the nozzle 135 and poured onto the inspection surface 1 a of the inspection object 1.

  The operation control unit 151 b transmits a signal indicating that the operation has been performed to the movement control device 126. The operation control unit 151b that has received the signal moves the slide block 124, and thus the ultrasonic sensor 141, in a predetermined direction by a predetermined distance (for example, several mm).

  The operation control unit 151b transmits a signal indicating that the operation is performed to the ultrasonic transmitter 142. The ultrasonic transmitter 142 that has received the signal applies a voltage having a predetermined frequency to the transducer of the ultrasonic sensor 141 for a predetermined time. As a result, the ultrasonic sensor 141 (the vibrator) transmits ultrasonic waves having a predetermined frequency for a predetermined time.

The timing at which the operation control unit 151b transmits a signal indicating that the operation control unit 151b operates to the movement control device 126 is synchronized with the timing at which the operation control unit 151b transmits a signal indicating that the operation control unit 151b operates on the ultrasonic transmitter 142.
That is, by alternately transmitting these signals, movement of the slide block 124 (ultrasonic sensor 141) by a predetermined distance and transmission of ultrasonic waves by the ultrasonic sensor 141 (vibrator thereof) are alternately performed.

The defect determination unit 151 c determines whether or not there is a defect inside the inspection object 1.
Substantially, the unit main body 151 performs a predetermined calculation or the like according to the defect determination program stored in the unit main body 151, thereby serving as the defect determination unit 151c.
Based on the electrical signal converted by the ultrasonic receiver 143 and the timing at which the operation control unit 151b transmits a signal indicating that the ultrasonic transmitter 142 operates, the defect determination unit 151c or (a) in FIG. As shown in (b), “the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 (in this embodiment, it is expressed in the form of“ voltage ”) and the ultrasonic sensor 141 is reflected after transmitting the ultrasonic wave. A graph indicating the relationship with the time (reception time) until receiving the ultrasonic wave (hereinafter referred to as “ultrasonic wave intensity-reception time graph”) ”is generated.
The “ultrasonic wave intensity-reception time graph” generated by the defect determination unit 151c is appropriately stored by the storage unit 151a.

The defect determination unit 151c determines whether or not there is a defect inside the inspection object 1 based on the generated “ultrasonic wave intensity-reception time graph”.
There is a correlation between the horizontal axis (reception time) of the “ultrasonic wave intensity-reception time graph” as shown in FIGS. 2A and 2B and the depth of the inspection object 1 from the inspection surface 1a. There is a correlation between the vertical axis (peak value of voltage) and the size of the defect that reflects ultrasonic waves.
The defect determination unit 151c uses the correlation between the reception time and the depth of the inspection object 1 from the inspection surface 1a and the correlation between the peak value of the voltage and the size of the defect (the inspection object position). 1) and the size of the defect.
Determination results regarding the presence / absence of a defect, the position of the defect, and the size of the defect by the defect determination unit 151c are appropriately stored in the storage unit 151a.

The contact medium determination unit 151d is an embodiment of the contact medium determination unit according to the present invention, and determines whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. Is.
Substantially, the unit main body 151 performs a predetermined calculation or the like according to the contact medium determination program stored in the unit main body 151, thereby functioning as the contact medium determination unit 151d.

  Hereinafter, the procedure of determination by the contact medium determination unit 151d (determination of whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1) will be described.

First, the contact medium determination unit 151d generates a quartic function (Y = aX ⁴ + bX ³ + cX ² + dX + e) that approximates the graph based on the “ultrasonic wave intensity-reception time graph” generated by the defect determination unit 151c. To do.
The generated quartic function is appropriately stored in the storage unit 151a.

As shown in FIG. 2A, when the contact medium 5 is supplied at a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected, it is relatively received in the “ultrasonic wave intensity-reception time graph”. A high voltage peak group can be seen in a region where the time is short (in this embodiment, a region where the reception time is t0 or more and t1 or less).
On the other hand, as shown in FIG. 2B, when the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected, “ultrasonic intensity-reception time graph”. In the region where the reception time is relatively short (in this embodiment, the region where the reception time is t0 or more and t1 or less), no high voltage peak group is seen.
In the present embodiment, the voltage peak group corresponding to the region where the reception time is t0 or more and t1 or less corresponds to the ultrasonic wave reflected by the contact medium 5.

When generating a quartic function, it is necessary to set in advance the lower limit value t0 and the upper limit value t1 of the reception time.
The contact medium determination unit 151d substantially actually detects the ultrasonic sensor based on the intensity of the ultrasonic wave reflected by the contact medium 5 and received by the ultrasonic sensor 141 if there is no abnormality in the ultrasonic inspection apparatus 100. It is determined whether or not the contact medium 5 is supplied to a position between 141 and the object 1 to be inspected.
Accordingly, the lower limit value t0 and the upper limit value t1 of the reception time are the distance L from the ultrasonic sensor 141 to the surface 1a to be inspected 1 and the velocity (sound speed) V of the ultrasonic wave propagating through the contact medium 5. Calculated based on “the ultrasonic wave is transmitted from the ultrasonic sensor 141 and then reflected by the boundary between the contact medium 5 and the inspection object 1 (inspected surface 1a in this embodiment) and is reflected on the ultrasonic sensor 141. It is desirable that the time required for reception (= 2 L / V) is satisfied (0 ≦ t0 <t1 ≦ 2 L / V is satisfied).
Further, from the viewpoint of maximally reflecting the ultrasonic wave reflected by the contact medium 5 in the determination as to whether or not the contact medium 5 is supplied to the position between the ultrasonic sensor 141 and the object 1 to be inspected, t0 It is desirable to set the value as close to 0 (zero) as possible and t1 as close to 2 L / V as possible.

In the case of the present embodiment, a quartic function (represented by a thick solid line in FIG. 2A) generated corresponding to the “ultrasonic wave intensity-reception time graph” shown in FIG. It is generated for a region (t0 ≦ X ≦ t1) in which the reception time is t0 or more and t1 or less, and is expressed by Y = a ₁ X ⁴ + b ₁ X ³ + c ₁ X ² + d ₁ X + e ₁ .
In addition, the quartic function (represented by a thick solid line in FIG. 2B) generated corresponding to the “ultrasonic wave intensity-reception time graph” shown in FIG. This is generated for a region (t0 ≦ X ≦ t1) that is t1 or less, and is represented by Y = a ₂ X ⁴ + b ₂ X ³ + c ₂ X ² + d ₂ X + e ₂ .

When the “ultrasonic wave intensity-reception time graph” shown in FIG. 2A is approximated by a higher-order function of the third order or higher (in this embodiment, a quartic function), the “ultrasonic wave” shown in FIG. There is a tendency that the absolute value of the second-order or higher coefficient becomes larger than when the “strength-reception time graph” is approximated by a third-order or higher-order function.
In the case of the “ultrasonic wave intensity-reception time graph” shown in FIG. 2A, a peak group of ultrasonic waves reflected by the contact medium 5 appears in a region where the horizontal axis (reception time) is close to zero. Because.
Further, in the “ultrasonic wave intensity-reception time graph” shown in FIG. 2A and the “ultrasonic wave intensity-reception time graph” shown in FIG. 2B, a voltage peak due to a disturbance element such as noise is present. When superposed, the absolute values of the higher-order function quadratic coefficients approximating these “ultrasonic wave intensity-reception time graphs” do not change significantly.

Next, the contact medium determination unit 151d is supplied with the contact medium 5 at a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected based on the calculated quadratic or higher-order coefficient value. It is determined whether or not.
More specifically, the contact medium determination unit 151d determines the absolute value | a | of the fourth-order coefficient a of the fourth-order function corresponding to the “ultrasonic wave intensity-reception time graph” generated by the defect determination unit 151c, and the third-order coefficient. the absolute value | b | of the b and the absolute value | c | of the second-order coefficient c, the absolute value | a ₀ | of the reference value a ₀ of the fourth-order coefficient stored in advance by the storage unit 151a, and the third-order coefficient the absolute value of the reference value _{b 0 | b 0 |,} and secondary absolute value of the reference value _{c 0} of the coefficient | _{c 0} | a, compare.
As a result, the contact medium determination unit 151d determines that if (A) | a | ≧ | a ₀ | and | b | ≧ | b ₀ | and | c | ≧ | c ₀ | The contact medium 5 is supplied to a position sandwiched between 141 and the inspection object 1 (more precisely, the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. "Ultrasonic intensity-reception time graph" is generated on the basis of the ultrasonic wave transmitted and received in (1).
The contact medium determining unit 151d _{includes, (B) | a | <} | a 0 |, | b | <| b 0 |, | c | <| c 0 | if at least one is satisfied out of the " The contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 (more precisely, the contact medium 5 is supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1. The “ultrasonic wave intensity-reception time graph” is generated based on the ultrasonic waves transmitted and received in the state of not being) ”.
The determination result by the contact medium determination unit 151d is appropriately stored in the storage unit 151a.

  In this embodiment, as a specific example in the case where it is determined that “the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”, the contact medium 5 is accommodated in the tank 131. If not (when the tank 131 is empty), if the pump 133 fails and the contact medium 5 cannot be pumped (or if the amount of pumping the contact medium 5 is small), the second transfer For example, when the middle part of the pipe 134 is broken and the contact medium 5 leaks, the direction of the nozzle 135 fixed to the slide block 124 is changed.

In the case of the present embodiment, the absolute value | a ₁ | of the quartic coefficient a ₁ of the quartic function generated corresponding to the “ultrasound intensity-reception time graph” shown in FIG. the absolute value of the coefficient _{b 1} | _{b 1} | and secondary absolute values of the coefficients _{c 1} | _{c 1} | is the absolute value of the reference values _{a 0} for each quartic coefficients _{| a} 0 |, the reference value of the third-order coefficient b absolute value of _{0 | b} 0 |, and the absolute value of the reference value _{c 0} of the secondary coefficients | _{c 0} | to be greater than _the value of a 0, _{b 0} and _{c 0} are set (| a ₁ | ≧ | a ₀ | and | b ₁ | ≧ | b ₀ | and | c ₁ | ≧ | c ₀ |).
Also, it is shown in FIG. 2 (b) - the absolute value of the fourth order coefficient a2 quartic functions generated in response to the "ultrasonic intensity received time graph" | a 2 _|, tertiary absolute coefficient b ₂ The value | b ₂ | and the absolute value | c ₂ | of the second order coefficient c ₂ are the absolute value | a ₀ | of the reference value a ₀ of the fourth order coefficient and the absolute value of the reference value b ₀ of the third order coefficient | The values of a ₀ , b ₀ and c ₀ are set to be smaller than b ₀ | and the absolute value | c ₀ | of the reference value c ₀ of the secondary coefficient (| a ₂ | <| a ₀ | and _{| b 2 | <| b 0} | and _{| c 2 | <| c 0} | is satisfied).
Accordingly, the contact medium determination unit 151d determines that the “ultrasonic intensity-reception time graph” as shown in FIG. 2A is “positioned between the ultrasonic sensor 141 and the inspection object 1”. When it is determined that the contact medium 5 is being supplied, and an “ultrasonic wave intensity-reception time graph” as illustrated in FIG. 2B is generated, the “ultrasonic sensor 141 and the object 1 to be inspected” It is determined that the contact medium 5 has not been supplied to the sandwiched position.

Reference value a ₀ quartic coefficients previously stored in the storage unit _151a, the reference value c ₀ of the reference value b ₀ and the secondary coefficient of the third order coefficient is determined in advance by experiments or the like.
Reference value a ₀ of fourth order _coefficient, tertiary Specific examples of experiments for obtaining a reference value b ₀ and a secondary reference value c ₀ of the coefficient of the coefficient, the inspection couplant supply mechanism 130 and the ultrasonic sensor 141 The ultrasonic sensor 141 receives ultrasonic waves (reflected waves) while appropriately changing the amount of the contact medium 5 supplied to the position sandwiched between the objects 1 (volume of the contact medium 5 per unit time pumped by the pump 133). An experiment that compares the coefficients of the quadratic function or higher that are generated based on a plurality of “ultrasonic wave intensity-reception time graphs” performed and the like is performed.

When the contact medium determination unit 151 d determines that “the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”, the contact medium determination unit 151 d transmits an alarm signal to the display device 153.
When the display device 153 receives an alarm signal from the contact medium determination unit 151d, the display device 153 displays the word “no contact medium is supplied”.
As described above, the display device 153 is an embodiment of the alarm generation unit according to the present invention, and the contact medium 5 is supplied to a position where the contact medium determination unit 151d is sandwiched between the ultrasonic sensor 141 and the inspection object 1. If it is determined that it is not, an alarm is issued.

When the contact medium determination unit 151d determines that “the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”, the movement control device 126 performs the operation of the movement mechanism 120. A signal for instructing stop (moving unit stop signal) is transmitted.
The movement mechanism 120 (the movement control device 126) that has received the movement unit stop signal from the contact medium determination unit 151d stops the driving of the motor 125 and the movement of the slide block 124.

When the contact medium determination unit 151d determines that “the contact medium 5 is not supplied to a position between the ultrasonic sensor 141 and the inspection object 1”, the contact medium determination unit 151d instructs the pump 133 to stop the operation of the pump 133. A signal (pumping stop signal) for transmitting is transmitted.
The contact medium supply mechanism 130 (the pump 133) that has received the pressure stop signal from the contact medium determination unit 151d stops the pumping of the contact medium 5 by the pump 133.

As above,
The ultrasonic inspection apparatus 100
A contact medium supply mechanism 130 for supplying the contact medium 5 to the surface 1a to be inspected 1;
An ultrasonic sensor 141 that transmits ultrasonic waves toward the inspection object 1 via the contact medium 5, receives ultrasonic waves reflected by the inspection object 1 and the contact medium 5, and detects the intensity of the received ultrasonic waves. When,
“Graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time from when the ultrasonic sensor 141 transmits the ultrasonic wave until the reflected ultrasonic wave is received (ultrasonic wave intensity−reception time A quadratic function (Y = aX ⁴ + bX ³ + cX ² + dX + e) that approximates the graph), and the values of the quadratic function and higher coefficients (quartic coefficient a, cubic coefficient b, and quadratic function) A contact medium determination unit 151d that determines whether or not the contact medium 5 is supplied to a position between the ultrasonic sensor 141 and the inspection object 1 based on the coefficient c) of
It comprises.
This configuration has the following advantages.
That is, the contact medium determination unit 151d indicates the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time from when the ultrasonic sensor 141 transmits the ultrasonic wave until reception of the reflected ultrasonic wave. In order to determine whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1 on the basis of the value of the quadratic function or more of the quadratic function that approximates the graph, Compared with the case where the determination is based only on the intensity (voltage) of the ultrasonic wave in the graph, it is less susceptible to disturbances such as noise, and the determination result is highly stable (highly robust).
Therefore, the ultrasonic inspection apparatus 100 can accurately determine whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.

In the present embodiment, the contact medium determination unit 151d has a relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time from when the ultrasonic sensor 141 transmits the ultrasonic wave until reception of the reflected ultrasonic wave. Although a quartic function approximating the graph shown (ultrasonic wave intensity-reception time graph) is generated, the present invention is not limited to this.
For example, the contact medium determination unit may generate a cubic function approximating the “ultrasonic wave intensity-reception time graph” or a higher-order function of the fifth or higher order.

The contact medium determination unit 151d of the ultrasonic inspection apparatus 100 is
A graph (ultrasound intensity-reception time graph) showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time from when the ultrasonic sensor 141 transmits the ultrasonic wave until receiving the reflected ultrasonic wave ) Is equal to or greater than a preset value (in the present embodiment, | a | ≧ | a ₀ | and | b | ≧ | b ₀ |). And when | c | ≧ | c ₀ | is satisfied), it is determined that the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected.
If the absolute value of the secondary or higher order coefficient of the quartic function is less than a preset value (in this embodiment, | a | <| a 0 |, | b | <| b 0 |, | c When at least one of | <| c ₀ | is satisfied), it is determined that the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1.
With this configuration, it is possible to accurately determine whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.

In the present embodiment, a graph (ultrasonic wave) showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time from when the ultrasonic sensor 141 transmits the ultrasonic wave until the reflected ultrasonic wave is received. The ultrasonic sensor 141 and the inspection object 1 using all the absolute values (| a |, | b |, and | c |) of the quadratic function quadratic function approximating (intensity-reception time graph). Although the presence or absence of the contact medium 5 supplied to the sandwiched position is determined, the present invention is not limited to this.
For example, using any one of the absolute values of the quadratic function quadratic function approximating the “ultrasonic wave intensity-reception time graph”, it is supplied to the position sandwiched between the ultrasonic sensor and the object to be inspected. The presence or absence of a contact medium may be determined.

In addition, the ultrasonic inspection apparatus 100 includes:
When the contact medium determination unit 151d determines that the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected, a word “contact medium is not supplied” is displayed. A display device 153 that issues an alarm is provided.
With this configuration, the operator can easily recognize that the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.

In the present embodiment, the display device 153 issues a warning by displaying the phrase “no contact medium is supplied”, but the present invention is not limited to this.
As other embodiment of the alarm generation part which concerns on this invention, the alarm device (buzzer) which generate | occur | produces a sound, the lamp which lights or blinks, etc. are mentioned.

In addition, the ultrasonic inspection apparatus 100 includes:
A moving mechanism 120 for moving the ultrasonic sensor 141 relative to the inspection surface 1a of the inspection object 1 is provided.
By comprising in this way, it is possible to test | inspect about several position of the to-be-inspected object 1. FIG.

The moving mechanism 120 of the present embodiment moves the ultrasonic sensor 141 only in a uniaxial direction parallel to the surface 1a to be inspected 1 (direction parallel to the longitudinal direction of the rail 122). Is not limited to this.
For example, the ultrasonic sensor may be moved in two axial directions that are parallel to the surface to be inspected and not parallel to each other.

Although the moving mechanism 120 of this embodiment moves the slide block 124 to which the ultrasonic sensor 141 is fixed by the rotation of the ball screw 123, the moving unit according to the present invention is not limited to this.
For example, an ultrasonic sensor may be fixed to the tip of the robot arm, and the ultrasonic sensor may move along the surface to be inspected by operating the robot arm.

In the present embodiment, the inspection object 1 is placed (stationary) on the inspection table 110, and the slide block 124 and the ultrasonic sensor 141 are moved. However, the present invention is not limited to this.
For example, the ultrasonic sensor 141 is fixed (stationary) at a predetermined position, and the ultrasonic sensor 141 moves (relatively moves) relative to the inspection object 1 when the inspection object 1 moves. Also good.

The moving mechanism 120 of the ultrasonic inspection apparatus 100 is
By fixing the nozzle 135 and the ultrasonic sensor 141, which are the discharge ports of the contact medium 5 in the contact medium supply mechanism 130, to the slide block 124, while maintaining the relative positions of the nozzle 135 and the ultrasonic sensor 141, Relative movement is performed along the inspection surface 1a of the inspection object 1.
With this configuration, even when the ultrasonic sensor 141 moves relative to the inspection object 1, the contact medium 5 is stably supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. As a result, the reliability of the inspection result of the inspection object 1 by the ultrasonic inspection apparatus 100 is improved.

The moving mechanism 120 of the ultrasonic inspection apparatus 100 is
When the contact medium determination unit 151d determines that the contact medium 5 is not supplied at a position between the ultrasonic sensor 141 and the inspection object 1, the slide block 124, and thus the ultrasonic sensor 141 (and the nozzle 135) moves. To stop.
By configuring in this way, it is possible to prevent the inspection from being continued in a state where the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 and to improve the reliability of the inspection result. It is possible.
In addition, by preventing the inspection from continuing in a state where the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1, the inspection object 1 that has been previously inspected. It is possible to eliminate waste in the inspection work such as performing the inspection again (in order to ensure the inspection), thereby contributing to the improvement of the work efficiency.

In the present embodiment, one ultrasonic sensor 141 transmits an ultrasonic wave toward the inspection object 1 via the contact medium 5 and receives and receives the ultrasonic wave reflected by the inspection object 1 and the contact medium 5. The intensity of ultrasonic waves is detected, but the present invention is not limited to this.
For example, the first ultrasonic sensor that transmits ultrasonic waves toward the inspection object via the contact medium, and the ultrasonic wave reflected by the inspection object and the contact medium are received and received via the contact medium. You may use two ultrasonic sensors of the 2nd ultrasonic sensor which detects the intensity | strength of an ultrasonic wave.

Hereinafter, an embodiment of the ultrasonic inspection method according to the present invention will be described with reference to FIG.
One embodiment of the ultrasonic inspection method according to the present invention is a method for inspecting the inspection object 1 using the ultrasonic inspection apparatus 100.
As shown in FIG. 3, one embodiment of the ultrasonic inspection method according to the present invention mainly includes a setting step S1100, an inspecting object placing step S1200, a contact medium supply starting step S1300, a moving step S1400, and an ultrasonic transmission / reception step. S1500, ultrasonic intensity-reception time graph generation step S1600, contact medium determination step S1700, movement determination step S1800, normal stop step S1900, alarm generation step S2000, and emergency stop step S2100.

The setting step S1100 is a step of performing settings for properly operating the ultrasonic inspection apparatus 100. The setting in the setting step S1100 includes (1) input of an identification number (lot number, etc.) of the inspection object 1 and conditions of incidence of ultrasonic waves from the ultrasonic sensor 141 to the inspection object 1 (ultrasonic frequency, incidence angle). input etc.), (3) input of reference values _{a 0, b 0, c 0} , the input of the moving speed and the moving pitch of the ultrasonic sensor 141, and the like.
In the setting step S1100, the operator performs input operations such as (1) to (3) above.
When the setting process S1100 is completed, the process proceeds to the inspection object placing process S1200.

  In the case where the ultrasonic inspection apparatus 100 sequentially inspects a plurality of inspection objects 1, 1..., The setting step S 1100 is performed only when inspecting the first inspection object 1 and thereafter the setting step S 1100 is performed. Can be omitted.

The inspection object placing step S1200 is a process of placing the inspection object 1 on a predetermined inspection position (in this embodiment, the upper surface of the inspection table 110).
In the inspection object placement step S1200, the operator holds the inspection object 1 by hand and places it on the upper surface of the inspection table 110, and places the ultrasonic sensor 141 on the inspection surface 1a of the inspection object 1 at a predetermined distance. Opposite each other with a gap.
When the inspection object placement step S1200 is completed, the process proceeds to the contact medium supply start step S1300.

In the present embodiment, the operator holds the inspection object 1 by hand and places it on the upper surface of the inspection table 110, but the present invention is not limited to this.
For example, the inspection object may be placed at a predetermined inspection position by using a transport device such as a belt conveyor that can sequentially transport a plurality of inspection objects.

The contact medium supply start step S1300 is a step of starting supply of the contact medium 5 to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.
In the contact medium supply start step S1300, the operation control unit 151b transmits a signal indicating that the pump 133 operates. The pump 133 that has received the signal pumps the contact medium 5.
As a result, the contact medium 5 is discharged from the nozzle 135, and the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1 (hereinafter, the ultrasonic sensor 141 and the inspection object 1). The supply of the contact medium 5 to the sandwiched position is continued until a transition is made to a normal stop step S1900 or an emergency stop step S2100 described later).
When the contact medium supply start step S1300 ends, the process proceeds to the movement step S1400.

The moving step S1400 is an embodiment of the moving step according to the present invention, and is a step of relatively moving the ultrasonic sensor 141 along the inspection surface 1a of the inspection object 1.
In the movement step S1400, the operation control unit 151b transmits a signal indicating that the operation has been performed to the movement control device 126. The operation control unit 151b that has received the signal moves the slide block 124, and thus the ultrasonic sensor 141, by a predetermined distance in a predetermined direction.
When the moving step S1400 is completed, the process proceeds to the ultrasonic wave transmitting / receiving step S1500.

The ultrasonic transmission / reception step S1500 is an embodiment of the ultrasonic transmission / reception step according to the present invention, and the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. Then, the ultrasonic sensor 141 transmits an ultrasonic wave toward the inspection object 1 through the contact medium 5, receives the ultrasonic wave reflected by the inspection object 1 and the contact medium 5, and the intensity of the received ultrasonic wave It is the process of detecting.
In the ultrasonic transmission / reception step S1500, the operation control unit 151b transmits a signal indicating that the ultrasonic transmission unit 142 operates. The ultrasonic transmitter 142 that has received the signal applies a voltage to the transducer of the ultrasonic sensor 141. As a result, the ultrasonic sensor 141 transmits an ultrasonic wave having a predetermined frequency.
The ultrasonic wave transmitted by the ultrasonic sensor 141 is incident on the inspection object 1 through the contact medium 5. The ultrasonic wave reflected by the contact medium 5 and the inspection object 1 is received by the ultrasonic sensor 141, and an electric signal indicating the intensity and frequency of the received ultrasonic wave is generated. The ultrasonic receiver 143 that has received the electric signal generated by the ultrasonic sensor 141 converts the electric signal into an electric signal that can be received by the defect determination unit 151c (unit main body 151), and transmits the electric signal to the defect determination unit 151c.
When the ultrasonic transmission / reception step S1500 ends, the process proceeds to the ultrasonic intensity-reception time graph generation step S1600.

The ultrasonic intensity-reception time graph generation step S1600 is an embodiment of the ultrasonic intensity-reception time graph generation step according to the present invention. The ultrasonic intensity detected by the ultrasonic sensor 141 and the ultrasonic transmission / reception are received. This is a step of generating a graph showing a relationship with a time (reception time) from when an ultrasonic wave is transmitted to when a reflected ultrasonic wave is received in step S1500, that is, an “ultrasonic wave intensity-reception time graph”.
In the ultrasonic intensity-reception time graph generation step S1600, the defect determination unit 151c, based on the electrical signal received from the ultrasonic receiver 143, “ultrasonic intensity-reception” as shown in FIG. Time graph "is generated.
When the ultrasonic intensity-reception time graph generation step S1600 ends, the process proceeds to the contact medium determination step S1700.
After the ultrasonic intensity-reception time graph generation step S1600 is completed, the defect determination unit 151c is the original purpose of the ultrasonic inspection apparatus 100 based on the generated “ultrasonic intensity-reception time graph”. “Determining whether or not there is a defect inside the inspection object 1”.

The contact medium determination step S1700 is an embodiment of the contact medium determination step according to the present invention. The contact medium determination step S1700 approximates the graph (ultrasonic intensity-reception time graph) generated in the ultrasonic intensity-reception time graph generation step S1600. A quadratic function (Y = aX ⁴ + bX ³ + cX ² + dX + e) is generated, and the value of the quadratic function or higher-order coefficient (in this embodiment, the absolute value | a | of the fourth-order coefficient a, the third-order coefficient Based on the absolute value | b | of b and the absolute value | c | of the secondary coefficient c, it is determined whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected. It is a process to do.
In the contact medium determination step S1700, the contact medium determination unit 151d determines that (A) | a | ≧ | a ₀ | and | b | ≧ | b ₀ | and | c | ≧ | c ₀ | It is determined that the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1, and (B) | a | <| a ₀ |, | b | <| b ₀ |, | When at least one of c | <| c ₀ | holds, it is determined that “the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”.

When the contact medium determination unit 151d determines that “the contact medium 5 is supplied at a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”, the process proceeds to the movement determination step S1800.
When the contact medium determination unit 151d determines that “the contact medium 5 is not supplied at a position sandwiched between the ultrasonic sensor 141 and the inspection object 1”, the contact medium determination unit 151d proceeds to the alarm generation step S2000.

The movement determination step S1800 is a step of determining whether or not the ultrasonic sensor 141 needs to move.
In the movement determination step S1800, the operation control unit 151b determines whether or not the ultrasonic sensor 141 needs to move based on the relative position of the ultrasonic sensor 141 (slide block 124) with respect to the inspection object 1. .
Specifically, the operation control unit 151b determines the relative position of the ultrasonic sensor 141 with respect to the inspection object 1 and the “final position (inspection of the inspection object 1 by the ultrasonic inspection apparatus 100 performed by the storage unit 151a in advance). The final position of the ultrasonic sensor 141 when it is performed without delay) is compared.
As a result, the operation control unit 151b determines that “the ultrasonic sensor 141 needs to move” when the relative position of the ultrasonic sensor 141 with respect to the inspection object 1 has not reached the final position. When the relative position of the ultrasonic sensor 141 with respect to the inspection object 1 has reached the final position, it is determined that “the ultrasonic sensor 141 does not need to move”.

When the operation control unit 151b determines that “the ultrasonic sensor 141 needs to move”, the process proceeds to the moving step S1400.
That is, when the state in which the contact medium 5 is properly supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 continues, the moving process S1400 → until the ultrasonic sensor 141 reaches the final position. A series of cycles of ultrasonic transmission / reception step S1500 → ultrasonic wave intensity-reception time graph generation step S1600 → contact medium determination step S1700 → movement determination step S1800 → movement step S1400 →...

  When the operation control unit 151b determines that “the ultrasonic sensor 141 does not need to move”, the process proceeds to the normal stop step S1900.

The normal stop step S1900 is a step of stopping the supply of the contact medium 5 to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.
In the normal stop step S1900, the operation control unit 151b transmits a signal to stop the operation to the pump 133, and the pump 133 that has received the signal stops the pumping of the contact medium 5.
As a result, the supply of the contact medium 5 to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 is stopped.
When the normal stop step S1900 is finished, one embodiment of the ultrasonic inspection method according to the present invention (inspection of the inspection object 1 by the ultrasonic inspection apparatus 100) is finished.

  The completion of one embodiment of the ultrasonic inspection method according to the present invention through the normal stop step S1900 means that the contact medium 5 is properly supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. This means that the inspection object 1 has been inspected by the ultrasonic inspection apparatus 100, and the reliability of the obtained inspection result of the inspection object 1 is high.

The alarm generation step S2000 is an embodiment of the alarm generation step according to the present invention, and the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 in the contact medium determination step S1700. This is a step of issuing an alarm when it is determined.
In the alarm generation step S2000, the display device 153 displays the word “no contact medium is supplied”.
When the alarm generation step S2000 ends, the process proceeds to the emergency stop step S2100.

The emergency stop step S2100 is an embodiment of the emergency stop step according to the present invention, and the relative movement of the ultrasonic sensor 141 and the supply of the contact medium 5 to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 are performed. It is a process of stopping.
In the emergency stop step S2100, the operation control unit 151b transmits a signal indicating that the operation is stopped to the pump 133, and the pump 133 that has received the signal stops the pumping of the contact medium 5.
As a result, the supply of the contact medium 5 to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 is stopped.
In addition, after moving to the emergency stop step S2100, the operation control unit 151b does not transmit a signal indicating that the operation has been performed to the movement control device 126, so that the movement of the ultrasonic sensor 141 is stopped.
When the emergency stop step S2100 is completed, one embodiment of the ultrasonic inspection method according to the present invention (inspection of the inspection object 1 by the ultrasonic inspection apparatus 100) is ended.

  The fact that one embodiment of the ultrasonic inspection method according to the present invention ends through the emergency stop step S2100 means that the ultrasonic sensor 141 and the inspection object 1 are in the middle of the inspection of the inspection object 1 by the ultrasonic inspection apparatus 100. This means that the contact medium 5 is not properly supplied to the position sandwiched between the two.

As described above, one embodiment of the ultrasonic inspection method according to the present invention is as follows.
In a state where the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1, the ultrasonic sensor 141 transmits an ultrasonic wave toward the inspection object 1 via the contact medium 5, An ultrasonic transmission / reception step S1500 for receiving ultrasonic waves reflected by the inspection object 1 and the contact medium 5 and detecting the intensity of the received ultrasonic waves;
A graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor 141 and the time (reception time) from when the ultrasonic wave is transmitted until the reflected ultrasonic wave is received in the ultrasonic wave transmitting / receiving step S1500 ( Ultrasonic intensity-reception time graph generation step S1600 for generating (ultrasonic intensity-reception time graph),
A quadratic function that approximates the ultrasonic intensity-reception time graph generated in the ultrasonic intensity-reception time graph generation step S1600 is generated, and the values of the quadratic function and higher coefficients (in the case of the present embodiment, The absolute value | a | of the fourth-order coefficient a, the absolute value | b | of the third-order coefficient b, and the absolute value | c | A contact medium determination step S1700 for determining whether or not the contact medium 5 is supplied to the position to be
It comprises.
This configuration has the following advantages.
That is, it is less affected by disturbances such as noise than the case where the determination is based solely on the ultrasonic intensity (voltage) in the ultrasonic intensity-reception time graph, and the determination result is highly stable (highly robust). .
Therefore, one embodiment of the ultrasonic inspection method according to the present invention can accurately determine whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1. It is.

One embodiment of the ultrasonic inspection method according to the present invention is as follows.
In the contact medium determination step S1700,
When the absolute value of the quadratic or higher coefficient of the generated quaternary function is greater than or equal to a preset value (in this embodiment, | a | ≧ | a ₀ | and | b | ≧ | b ₀ | and When | c | ≧ | c ₀ | is satisfied), it is determined that the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the object 1 to be inspected.
When the absolute value of the quadratic or higher-order coefficient of the quartic function is less than a preset value (in this embodiment, | a | <| a ₀ |, | b | <| b ₀ |, | c When at least one of | <| c ₀ | is satisfied), it is determined that the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1.
With this configuration, it is possible to accurately determine whether or not the contact medium 5 is supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.

One embodiment of the ultrasonic inspection method according to the present invention is as follows.
In the contact medium determination step S1700, there is provided an alarm generation step S2000 that issues an alarm when it is determined that the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1.
With this configuration, the operator can easily recognize that the contact medium 5 is not supplied to a position sandwiched between the ultrasonic sensor 141 and the inspection object 1.

One embodiment of the ultrasonic inspection method according to the present invention is as follows.
A moving step S1400 for moving the ultrasonic sensor 141 relative to the inspection surface 1a of the inspection object 1 is provided.
By comprising in this way, it is possible to test | inspect about several position of the to-be-inspected object 1. FIG.

One embodiment of the ultrasonic inspection method according to the present invention is as follows.
In the contact medium determination step S1700, when it is determined that the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1, the relative movement of the ultrasonic sensor 141 and the ultrasonic sensor 141 and the inspection object are determined. The emergency stop process S2100 which stops supply of the contact medium 5 to the position pinched | interposed with 1 is comprised.
By configuring in this way, it is possible to prevent the inspection from being continued in a state where the contact medium 5 is not supplied to the position sandwiched between the ultrasonic sensor 141 and the inspection object 1 and to improve the reliability of the inspection result. It is possible.

In the present embodiment, when the alarm generation step S2000 is completed, the process proceeds to the emergency stop step S2100. However, the present invention is not limited to this.
For example, a configuration in which an alarm generation step and an emergency stop step are performed in parallel may be performed, or a configuration in which the operation proceeds to the alarm generation step when the emergency stop step is completed.

The figure which shows one Embodiment of the ultrasonic inspection apparatus which concerns on this invention. The figure which shows the "graph which shows the relationship between the intensity | strength of an ultrasonic wave, and reception time" which the one embodiment of the ultrasonic inspection apparatus which concerns on this invention and the quaternary function which approximates the said graph. The flowchart which shows one Embodiment of the ultrasonic inspection method which concerns on this invention. The figure which shows the "graph which shows the relationship between the intensity | strength of an ultrasonic wave, and reception time" which the conventional ultrasonic inspection apparatus produces.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspected object 1a Inspected surface 5 Contact medium 120 Moving mechanism (moving part)
130 Contact medium supply mechanism (contact medium supply unit)
141 Ultrasonic sensor 151d Contact medium determining unit 153 Display device (alarm generating unit)

Claims (11)

A contact medium supply unit for supplying a contact medium to the surface to be inspected of the object to be inspected;
An ultrasonic sensor that transmits ultrasonic waves to the inspection object through the contact medium, receives ultrasonic waves reflected by the inspection object and the contact medium, and detects the intensity of the received ultrasonic waves; ,
Third order or higher order approximation of a graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor and the time from when the ultrasonic sensor transmits the ultrasonic wave until it receives the reflected ultrasonic wave. A contact medium that generates a function and determines whether or not the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the object to be inspected based on a value of a second or higher order coefficient of the higher-order function A determination unit;
An ultrasonic inspection apparatus comprising: The contact medium determination unit includes:
When the absolute value of the quadratic or higher coefficient of the higher order function is equal to or greater than a preset value, it is determined that the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object. And
When the absolute value of the second or higher order coefficient of the higher order function is less than a preset value, it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object The ultrasonic inspection apparatus according to claim 1.   3. The alarm generation unit that issues an alarm when the contact medium determination unit determines that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object. The ultrasonic inspection apparatus described in 1.   The ultrasonic inspection apparatus according to any one of claims 1 to 3, further comprising a moving unit that relatively moves the ultrasonic sensor along an inspection surface of the inspection object. The moving unit is
While maintaining the relative positions of the contact medium discharge port and the ultrasonic sensor in the contact medium supply unit, the contact medium discharge port and the ultrasonic sensor in the contact medium supply unit are placed on the object to be inspected. The ultrasonic inspection apparatus according to claim 4, wherein the ultrasonic inspection apparatus is relatively moved along the inspection surface. The moving unit is
The relative movement of the ultrasonic sensor is stopped when the contact medium determination unit determines that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object. 5. The ultrasonic inspection apparatus according to 5. In a state where the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object, the ultrasonic sensor transmits an ultrasonic wave toward the inspection object through the contact medium, and the inspection object An ultrasonic transmission / reception step of receiving an ultrasonic wave reflected by an object and the contact medium, and detecting an intensity of the received ultrasonic wave;
Ultrasound that generates a graph showing the relationship between the intensity of the ultrasonic wave detected by the ultrasonic sensor and the time from the transmission of the ultrasonic wave to the reception of the reflected ultrasonic wave in the ultrasonic wave transmission / reception step Strength-reception time graph generation process;
A third order or higher order function approximating the graph generated in the ultrasonic intensity-reception time graph generation step is generated, and the ultrasonic sensor and the object to be measured are generated based on the value of the second order or higher coefficient of the higher order function. A contact medium determination step of determining whether or not the contact medium is supplied to a position sandwiched between the inspection object;
An ultrasonic inspection method comprising: In the contact medium determination step,
When the absolute value of the quadratic or higher coefficient of the higher order function is equal to or greater than a preset value, it is determined that the contact medium is supplied to a position sandwiched between the ultrasonic sensor and the inspection object. And
When the absolute value of the second or higher order coefficient of the higher order function is less than a preset value, it is determined that the contact medium is not supplied to a position sandwiched between the ultrasonic sensor and the inspection object The ultrasonic inspection method according to claim 7.   The alarm generation process which issues an alarm when it determines with the said contact medium not being supplied to the position pinched | interposed by the said ultrasonic sensor and the said to-be-inspected object in the said contact medium determination process is provided. The ultrasonic inspection method described in 1.   The ultrasonic inspection method according to any one of claims 7 to 9, further comprising a moving step of relatively moving the ultrasonic sensor along an inspection surface of the inspection object.   In the contact medium determination step, when it is determined that the contact medium is not supplied to a position between the ultrasonic sensor and the object to be inspected, relative movement of the ultrasonic sensor and the ultrasonic sensor and the object to be inspected The ultrasonic inspection method according to claim 10, further comprising an emergency stop step of stopping the supply of the contact medium to a position sandwiched between objects.

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