JP2005114439A - Hitting test method and apparatus - Google Patents

Abstract

An object of the present invention is to prevent the vibration of a portion other than the head of a hammer from being transmitted as a reflected wave to the object to be measured when the object to be measured is struck, and mixing an unnecessary noise impact waveform into the initial waveform immediately after the impact. When performing pass / fail judgment, it is possible to use an initial waveform having a large amplitude and a high value from about 20 ms immediately after striking so that the pass / fail of the object to be measured can be judged with higher accuracy and in a shorter time.
A hammer that strikes an object to be measured with a head, an acceleration sensor that detects an impact waveform generated by the impact, and a signal from the acceleration sensor is analyzed to determine whether the object to be measured is good or bad. In the impact test apparatus including the analysis and determination devices 15 and 16 for determining, the vibration of the portion other than the head 20 of the hammer 11 is not transmitted to the measured object 19 as a reflected wave when the measured object 19 is hit. The head 20 includes a hammer 11 that is vibration-insulated.
[Selection] Figure 2

Description

  The present invention relates to a laminated steel body having different physical properties (for example, a special heat-resistant material made of metal and ceramic, a heat-resistant tile made of metal and casting, etc.), a special heat-resistant material having impurities different from the essence in a single substance, etc. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a striking test method and apparatus for non-destructively determining the quality of an object to be measured. In particular, vibration insulation is provided between a hammer head and a portion other than the head, and an acceleration sensor is attached to the object to be measured. Therefore, at the time of striking, the vibration of the part other than the head is transmitted as a reflected wave to the object to be measured, and an unnecessary noise shock waveform is prevented from being mixed into the initial vibration waveform immediately after the striking, and it is hit when determining the quality of the object to be measured. Immediately after that, it is possible to use a high-value initial vibration waveform with a large amplitude up to about 20 ms, and it is possible to judge the quality of the object to be measured with high accuracy and in a short time, and 100% inspection is sufficiently possible. Such on hitting test method and apparatus.

  In the impact test, an object to be measured is impulse-excited, a vibration waveform detected by a vibration pickup (for example, an accelerometer) attached to the object to be measured is recorded, and the vibration waveform is subjected to FFT (Fast Fourier Transform). ) And the vibration characteristics of the object to be measured are clarified by reading the frequency component of the vibration waveform, the natural frequency component of the object to be measured, etc., and the natural frequency and natural vibration of the object to be measured. It is widely used to measure the mode, etc., and to determine the quality of the object to be measured.

However, the hammer 1 (impulse hammer) for exciting the object to be measured in FIG. 19 has a hammer head 2 fixedly attached to the tip of the handle 3 in the same manner as an ordinary hammer other than the conventional impulse hammer. Therefore, for example, when the object 4 is hit in the direction of arrow A, the head 2 cannot escape, and the moment of hitting becomes longer. In the case of hitting with a hammer, the vibration of the body of the worker holding the hammer 1 is also transmitted as a reflected wave to the object 4 to be measured, and the horizontal axis is time (sec), vertical As shown in the axis of acceleration of the object to be measured (m / sec ² ) generated by the impact, the reflected wave becomes a noise impact waveform 5 which is a distorted waveform and is mixed into the original initial vibration waveform, and these waveforms are The synthesized interference wave 6 is the initial vibration wave. It would be detected by the accelerometer as. For this reason, there is a problem that the initial vibration waveform from about 20 ms immediately after the impact cannot be used as analysis data.

  Such inconvenience is apparent from the description of Patent Document 1. That is, this document discloses a non-destructive inspection method, a non-destructive inspection device, and a quality control method for a sound-inspected object. In paragraph 0028 of the specification of this document, “Reception for 100 ms immediately after impact” is disclosed. The fact is that the initial vibration waveform is mixed with a noise shock waveform and is not suitable for analysis, as described in the statement “Exclude vibration from the object of analysis”. In addition, since the analysis is performed by expanding a vibration waveform with a small amplitude whose attenuation has been considerably advanced after 100 ms has passed from the impact by the amplifier, the determination is made when trying to determine the quality of the object to be measured. It is inevitable that the accuracy becomes low.

  The vibration waveform having the highest value because it contains the most important information for determining the vibration characteristics of the object to be measured and its quality is also an initial vibration waveform having a large amplitude within 100 ms, preferably within approximately 20 ms, immediately after impact. Therefore, if this initial vibration waveform can be used for analysis, it is possible to judge the quality of the object to be measured with higher accuracy, but in the conventional impact test, this initial vibration waveform can be used. could not.

JP 2002-340869 A

  The present invention has been made in order to eliminate the above-described drawbacks of the prior art. The object of the present invention is to detect a vibration waveform generated by hitting a hammer head with an acceleration sensor and analyze the vibration waveform. In the impact test method for determining whether the object to be measured is good or bad, the object to be measured is struck and excited by the head of the hammer whose head is vibration-insulated to generate a noise impact waveform and apply the noise impact waveform to the vibration waveform. By preventing mixing, it is possible to use an initial vibration waveform having a large amplitude and a high value from about 20 ms immediately after hitting to determine the quality of the object to be measured without generating an interference wave. It is to be able to determine the quality of an object with higher accuracy and in an extremely short time.

  Another object is to effectively use a lot of important information contained in the initial vibration waveform immediately after the impact by analyzing the initial wave vibration shape immediately after the impact and judging the quality of the measured object in the above method. In this way, it is possible to obtain extremely accurate judgment results that do not miss defective products, and this makes it possible to improve the reliability of parts that directly affect the performance of equipment and results in human lives like special heat-resistant materials. It is to prevent accidents caused by defective parts.

  Still another object of the present invention is to determine the quality of the measured object in a short time and with high accuracy by analyzing the initial vibration waveform from about immediately after hitting to about 20 ms and determining the quality of the measured object. In other words, it is possible to inspect all the objects to be measured such as special heat-resistant materials.

  Another object is to analyze a hammer that strikes the object to be measured by the head, an acceleration sensor that detects a vibration waveform generated by the impact, and a signal from the acceleration sensor to determine whether the object to be measured is good or bad. And a hammer test apparatus comprising a judgment device, comprising a hammer whose head is vibration-insulated so that vibration of a portion other than the head of the hammer is not transmitted to the workpiece as a reflected wave when the workpiece is hit, By analyzing the initial vibration waveform immediately after the impact from the signal from the acceleration sensor to determine the quality of the measurement object, the quality of the measurement object such as a special heat-resistant material can be determined with higher accuracy and shorter. In addition to being able to do it in time, it is also possible to detect and remove even one defective product having a defect or poor adhesion inside without overlooking by 100% inspection.

  Still another object of the present invention is to provide a hammer drive mechanism configured to swing the hammer to strike the object to be measured, an acceleration sensor attached to the object to be measured, and the acceleration sensor connected to the acceleration sensor. An acceleration amplifier that amplifies a signal from the sensor, an analysis device that is connected to the acceleration amplifier and analyzes using an initial vibration waveform immediately after hitting among signals from the acceleration amplifier, and analysis data obtained by the analysis device By using a determination device for determining pass / fail of the object to be measured and a display device for displaying a determination result by the determination device, detection, analysis and analysis of the initial vibration waveform from the object to be measured It is possible to automatically determine whether the product is good or not based on this, and it is determined that a defective product is a good product or a good product is determined to be a defective product. Without causing such a determination misses, yet efficiently it is to allow the inspection of the object to be measured.

  Another object of the present invention is to provide a hammer for hammering which is used for a hammering test and strikes a measured object with a head. By configuring so that the vibration of other parts is not transmitted as a reflected wave to the object to be measured, the vibration of the part other than the head is transmitted as a reflected wave to the object to be measured at the time of impact and is unnecessary noise in the initial vibration waveform immediately after the impact It is to be able to completely prevent the impact waveform from being mixed.

  Still another object is to arrange an elastic body between the head of the hammer and the handle in the above configuration, to fix the head and one end of the elastic body, and to connect the other end of the elastic body and the handle. By fixing and freeing the middle part of the elastic body, the head and the handle are vibrationally insulated so that the head escapes at the moment of striking, which is unnecessary for the initial vibration waveform immediately after striking. The noise shock waveform should not be mixed at all.

  Another object is to arrange a coil spring between the head and the handle, to fix the head to one end of the coil spring, and to fix the other end to the handle and the handle, By making the middle part of the coil spring free, the head and handle are vibrated and insulated, so the head escapes due to the deformation of the coil spring at the moment of striking, and unwanted noise is added to the initial vibration waveform immediately after striking It is an object of the present invention to provide a hammer for hammering tests that can completely prevent the damage.

  In short, the method of the present invention (Claim 1) is a striking test method in which a vibration waveform generated by striking a hammer head is detected by an acceleration sensor, and the vibration waveform is analyzed to determine the quality of the object to be measured. The object to be measured is struck and excited by the hammer-insulated hammer to prevent generation of a noise impact waveform and mixing of the noise impact waveform into the vibration waveform.

  Further, the method according to the present invention (Claim 2) is an impact test method in which a vibration waveform generated by hitting a hammer head is detected by an acceleration sensor, and the vibration waveform is analyzed to determine whether the object to be measured is good or bad. Analyzing the initial vibration waveform immediately after impact by striking and vibrating the object to be measured with the hammer-insulated hammer, preventing the generation of the noise impact waveform and mixing the noise impact waveform into the vibration waveform The quality of the object to be measured is determined.

  Further, the method of the present invention (Claim 3) is a striking test method in which a vibration waveform generated by striking a hammer head is detected by an acceleration sensor, and the vibration waveform is analyzed to judge the quality of the object to be measured. The vibration-insulated hammer head vibrates and vibrates the object to be measured to prevent generation of a noise shock waveform and mixing of the noise shock waveform into the vibration waveform, so that an initial vibration of about 20 ms immediately after the impact is obtained. It is characterized in that the quality of the object to be measured is determined by analyzing the waveform.

  The device of the present invention (Claim 4) includes a hammer that strikes the object to be measured by a head, an acceleration sensor that detects a vibration waveform generated by the impact, and a signal from the acceleration sensor to analyze the object to be measured. In the impact test apparatus comprising an analysis and determination device for determining the quality of the test object, the vibration of the portion other than the hammer head is not transmitted as a reflected wave to the object to be measured when the object to be measured is hit. Is provided with a vibration-insulated hammer, and an initial vibration waveform immediately after striking is analyzed among the signals from the acceleration sensor to determine whether the object to be measured is good or bad.

  The apparatus of the present invention (Claim 5) includes a hammer in which the head is vibration-insulated so that vibration of a portion other than the head is not transmitted as a reflected wave to the object to be measured when the object to be measured is struck. A hammer drive mechanism configured to strike the object to be measured by swinging the object, an acceleration sensor attached to the object to be measured, and an acceleration amplifier connected to the acceleration sensor and amplifying a signal from the acceleration sensor And an analysis device connected to the acceleration amplifier for analysis using an initial vibration waveform immediately after hitting among signals from the acceleration amplifier, and using the analysis data obtained by the analysis device, The apparatus includes a determination device that determines pass / fail and a display device that displays a determination result of the determination device.

  Further, the hammer for hammering test according to the present invention (Claim 6) is a hammer for hammering test which is used in the hammering test and hits the object to be measured with the head, and vibrationally insulates between the head and the part other than the head. The present invention is characterized in that the vibration of the part other than the head is not transmitted as a reflected wave to the object to be measured when hitting the object to be measured.

  Further, the hammer for hammering test of the present invention (Claim 7) is an hammer for hammering test used for hitting a measurement object with a head used in a hammering test, wherein an elastic body is disposed between the head and a handle, While fixing the head and one end of the elastic body, the other end of the elastic body and the handle are fixed, and an intermediate portion of the elastic body is set in a free state between the head and the handle. Is configured so that vibration on the handle side is not transmitted as a reflected wave to the object to be measured when hitting the object to be measured.

  Further, the hammer for hammering test of the present invention (Claim 8) is a hammer for hammering test which is used in a hammering test and hits an object to be measured with a head, and a coil spring is disposed between the head and a handle, The head and one end of the coil spring are fixed together, the other end of the coil spring and the handle are fixed, and an intermediate portion of the coil spring is set in a free state between the head and the handle. Is configured so that vibration on the handle side is not transmitted as a reflected wave to the object to be measured when hitting the object to be measured.

  The present invention provides an impact test method in which a vibration waveform generated by hitting a hammer head as described above is detected by an acceleration sensor, and the vibration waveform is analyzed to determine whether the object to be measured is good. The object to be measured is struck and vibrated by the head of the hammer, and the generation of the noise shock waveform and the mixing of the noise shock waveform into the vibration waveform are prevented, so that no interference wave is generated. In determining the quality of an object, it is possible to use an initial waveform having a large amplitude and a high value from about immediately after hitting to about 20 ms, and it is possible to determine the quality of an object to be measured with higher accuracy.

  Also, in the above method, since the initial waveform immediately after hitting is analyzed to determine the quality of the object to be measured, a lot of important information contained in the initial vibration waveform immediately after hitting is effectively used to obtain a defective product. It has the effect of obtaining highly accurate judgment results that do not overlook, and this also increases the reliability of parts that directly affect the performance of equipment and results in human lives, such as special heat-resistant materials, and accidents caused by defective parts. The effect of preventing the above is obtained.

  Further, in the above method, the quality of the object to be measured is determined by analyzing the initial vibration waveform from about 20 ms immediately after the impact, so that the quality of the object to be measured can be determined with high accuracy in a short time. As a result, there is an effect that all the objects to be measured such as special heat-resistant materials can be inspected.

  Further, a hammer that strikes the object to be measured by the head, an acceleration sensor that detects a vibration waveform generated by the impact, and an analysis and determination device that analyzes the signal from the acceleration sensor and determines the quality of the object to be measured. The hammer test device is equipped with a hammer whose head is vibration-insulated so that the vibration of the part other than the hammer head is not transmitted to the object as a reflected wave when the object is hit. Because it is configured to analyze the initial vibration waveform immediately after hitting and judge the quality of the object to be measured, the quality of the object to be measured such as special heat-resistant material can be judged with high accuracy and in a short time, and the total number There is an effect that the inspection can find and remove any defective product having an internal defect or adhesion failure without overlooking it.

  Further, in the above configuration, a hammer driving mechanism configured to swing the hammer to strike the object to be measured, an acceleration sensor attached to the object to be measured, and a signal from the acceleration sensor connected to the acceleration sensor. An acceleration amplifier for amplification, an analysis device connected to the acceleration amplifier for analysis using an initial vibration waveform immediately after striking among signals from the acceleration amplifier, and an object to be measured using analysis data obtained by the analysis device Since a determination device for determining the quality of an object and a display device for displaying a determination result by the determination device are provided, detection and analysis of the initial vibration waveform from the hit of the measurement object and determination of the quality based on the analysis Can be automatically performed, and as a result, it is not possible to make a judgment mistake such as judging a defective product as a non-defective product, or judging a non-defective product as a defective product. , Yet the effect which can efficiently inspect the object to be measured is obtained.

  Further, in a hammer for hammering test, which is used for the hammering test and hits the object to be measured with the head, vibration is insulated between the head and the part other than the head so that the part other than the head is vibrated when hitting the object to be measured. Since it is configured not to be transmitted to the object to be measured as a reflected wave, it is possible to prevent the vibration of the part other than the head from being transmitted to the object to be measured as a reflected wave at the time of hitting and mixing unnecessary noise in the initial waveform immediately after hitting. effective.

  Further, in the above configuration, an elastic body is disposed between the head and the handle of the hammer, the head and one end of the elastic body are fixed, and the other end and the handle of the elastic body are fixed, Since the middle part of the elastic body is in a free state, the head and the handle are vibration-insulated, so the head escapes at the moment of striking, and no significant impact noise is mixed into the initial waveform immediately after striking. Is obtained.

  In addition, a coil spring is disposed between the head and the handle, and the head and one end of the coil spring are fixed, and the other end of the coil spring and the handle are fixed to each other. Since the head and the handle are vibration-insulated by leaving the head in a free state, the head escapes due to the deformation of the coil spring at the moment of striking, and it is possible to completely prevent unnecessary noise from being mixed into the initial waveform immediately after striking There is an effect of providing a test hammer.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings. The hammer test device 10 according to the present invention includes a hammer 11, a hammer drive mechanism 12, an acceleration sensor 13, an acceleration amplifier 14, an analysis device 15, and a determination device 16 in FIGS. 1 to 3 and 15. The display device 18 is provided.

  As shown in FIGS. 1 to 6, the hammer 11 prevents the vibration on the handle 21 side, which is an example of a portion other than the head 20, from being transmitted to the object 19 as a reflected wave when the object 19 is hit. The head 20 is vibration-insulated. For example, a coil spring 22 as an example of an elastic body is disposed between the head 20 and the handle 21, and the head 20 and one end 22 a of the coil spring 22 are fixed using, for example, an adhesive 23, and the coil spring 22 is fixed. The other end 22b and the handle 21 are fixed, and the intermediate portion 22c of the coil spring 22 is set in a free state so that the head 20 and the handle 21 are vibration-insulated.

  As shown in FIGS. 4 to 6, the adhesive is fixed by applying an adhesive to the fitting portion between the coil spring 22, the head 20 and the handle 21, and the intermediate portion 22 c of the coil spring 22 is fixed. It is not free.

  In the illustrated embodiment, the coil spring 22 is a cylindrical coil spring made of, for example, metal (spring steel, stainless steel, etc.), and has a free length of 20 mm, a coil outer diameter of 6 mmφ, a coil center diameter of 5.3 mmφ, and a wire diameter of 0. 0.7 mmφ, effective number of turns 15, spring constant 0.0488 N / cm (0.00498 kgf / cm), pitch is equal pitch.

  Although the mass of the head 20 is about 10 g, the coil spring 22 can support the head 20 even when the hammer 11 is in a horizontal state, and is easily deformed at the time of hitting and repelled the head. 20 can escape instantly. The specification of the coil spring 22 is not limited to the above, and may be a conical shape, a sag shape, a pinch shape, or an unequal pitch.

  The elastic body disposed between the head 20 and the handle 21 is not limited to the coil spring 22, but may be rubber such as silicon rubber, vulcanized rubber, nitrile rubber, natural rubber, in addition to an air spring and a thin plate spring. As long as the head 20 and the handle 21 can be vibration-insulated, any shape and material may be used.

  The handle 21 of the hammer 11 is formed with through holes 21 a, 21 b, 21 c for attaching the hammer 11 to the hammer drive mechanism 12.

  As shown in FIGS. 2 and 3, the hammer drive mechanism 12 is configured to swing the hammer 11 and hit the object 19 to be measured. The hammer drive mechanism 12 has an upper end of a column 25 upright on the base 24. The hammer 11 is swingably supported via a bracket 26. The head 20 of the hammer 11 is mounted upward and strikes the object 19 to be measured from the bottom to the top. The hammer 11 and the bracket 26 are attached through the pin 31 through the through hole 21 b of the hammer 11.

  In the middle of the column 25, a spring locking member 28 is fastened and fixed using a screw 29. For example, there is a tension between the spring locking member 28 and the through hole 21c of the handle 21 of the hammer 11. A spring 30 is attached to urge the hammer 11 in the striking direction.

  On the base 24, for example, a solenoid 33 is attached in an upright state, and a bracket 36 is attached to the upper end of the movable iron core 34 via an adjustment screw 35. The bracket 36 is attached to the handle 21 of the hammer 11. The through hole 21a is connected via a pin 32. The adjustment screw 35 is for adjusting the striking force so that the swing range of the hammer 11 can be finely adjusted.

  A power source 60 and a switch 61 are connected to the solenoid 33 as shown in FIGS. In the drawing, the power source 60 is shown as alternating current, but if the solenoid 33 is for direct current, it becomes direct current.

  One column 38 is attached to each of the four corners of the base 24, and an upper plate 39 is attached to the upper end thereof. The upper plate 39 is formed with a window 39a that allows the head 20 of the hammer 11 to enter and exit. A cover 40 is covered between the upper plate 39 and the base 24, and a wiring connector 50 is attached to the cover 40.

  As shown in FIGS. 1 to 3 and 8, for example, a pair of pedestals 41 for attaching the DUT 19 is attached to the upper plate 39. The pedestal 41 can be fixed to an arbitrary portion of a long hole 39 b formed in the upper plate 39.

  In FIG. 7, since the object to be measured 19 (for example, a special heat-resistant material) has various sizes, it is necessary to be able to change the position of the pedestal 41, and the hit is vibration in the object to be measured 19. Therefore, the mounting position of the DUT 19 can be adjusted. Thereby, it is possible to always hit an appropriate place regardless of the type of the object to be measured 19.

  The pedestal 41 has an elastic body 44 passed through a screw shaft at the center thereof, the elastic body 44 is sandwiched between the lower plate 43 and the upper plate 45, and a magnet plate 48 is overlapped on the upper plate 45. An engaging plate 46 formed with a notch 46 a that engages with the shape is overlapped with a magnet plate 48 and the whole is tightened with a nut 47.

The magnet plate 48 is used in the case where the measured object 19 is a special heat-resistant material made of a magnetic material, and the end 19a of the measured object 19 engaged with the engaging plate 46 is attracted by a magnetic force. For this reason, the object to be measured 19 can be easily attached and detached, and can be fixed with an appropriate restraining force.
When the object to be measured 19 is a non-magnetic material or does not contain any magnetic material and is not attracted to the magnet, an air suction port (not shown) is provided in the engagement plate 46 or the magnet plate 48, and the air The object to be measured 19 may be sucked from the outside by using negative pressure, or the object to be measured 19 may be lightly biased and pressed by a spring or the like.

  A cover 49 in which a window 49a having an appropriate size is formed is attached to the upper plate 39.

  As shown in FIG. 9, the acceleration sensor 13 is attached to the measured object 19, and generates a voltage proportional to the acceleration generated at the attachment position by the hammer 11 and outputs it through the lead wire 13a. It is configured. Note that the acceleration sensor preferably has a filter function for cutting off the low-frequency and high-frequency frequencies.

  In FIG. 15, the acceleration amplifier 14 is connected to the acceleration sensor 13 and amplifies a signal from the acceleration sensor 13. Since the acceleration sensor 13 generally has high impedance and is easily affected by noise, it is necessary to amplify the signal from the acceleration sensor 13 by the acceleration amplifier 14 having very high input impedance.

  The analysis device 15 is connected to the acceleration amplifier 14 and is an FFT frequency analyzer, for example, for analysis using the initial waveform 51a immediately after hitting among the signals (vibration waveform 51) from the acceleration amplifier 14. As shown in FIG. 16, the analysis device 15 is configured such that, for example, a frequency component included in the waveform can be obtained from the initial waveform 51 a and the power spectrum 52 at each frequency arranged in an arithmetic progression can be obtained. Yes.

  The determination device 16 is for determining the quality of the DUT 19 using the power spectrum 52 as an example of the analysis data obtained by the analysis device 15. The determination device 16 is an RMS (Root Mean Square) square of the power spectrum 52. The average square root) is obtained and the quality is determined by comparing with the value in the case of a non-defective product.

  The display device 18 is, for example, a display device for displaying the determination result by the determination device 16. For example, the display device 18 displays an “OK” character 53 when the determination is good, and an “NG” character 54 when the determination is bad. The display is configured so that an operator (not shown) can identify the quality of the object to be measured 19 at a glance.

  The method of the present invention (Claim 1) is a batting test method in which a vibration waveform generated by striking the head 20 of the hammer 11 is detected by the acceleration sensor 13 and the vibration waveform is analyzed to determine whether the object to be measured 19 is good or bad. In this method, the measurement object 19 is struck and vibrated by the head 20 of the hammer 11 in which the head 20 is vibration-insulated to prevent generation and mixing of noise impact waveforms.

  Further, the method of the present invention (Claim 2) is a batting test method in which a waveform generated by striking the head 20 of the hammer 11 is detected by the acceleration sensor 13, and the vibration waveform is analyzed to judge the quality of the object 19 to be measured. The head 20 of the hammer 11 with the vibration-insulated head 20 is oscillated and struck by the head 20, the generation and mixing of noise impact waveforms are prevented, and the initial vibration waveform 51 a immediately after the impact is analyzed to measure the object. 19 is a method for judging pass / fail.

  The method of the present invention (Claim 3) is a batting test method in which a vibration waveform generated by striking the head 11 of the hammer is detected by the acceleration sensor 13 and the vibration waveform is analyzed to judge the quality of the object 19 to be measured. In FIG. 2, the head 20 of the hammer 11 with vibration isolation is used to strike and vibrate the object to be measured 19 to prevent the generation and mixing of noise impact waveforms, and the initial vibration waveform 51a from about immediately after impact to about 20 ms. In this method, the quality of the DUT 19 is determined by analysis.

The present invention is configured as described above, and the operation thereof will be described below. When performing the impact test using the impact device 1, the position of the pedestal 41 in FIG. 3 and FIG. 9 is adjusted according to the measured object 19, and the measured object 19 is placed on the engagement plate 46 of the pedestal 41. It attaches horizontally so that the edge part 19a may engage. In the embodiment shown in the drawings, the object to be measured 19 is a special heat-resistant material in which ceramic is bonded to a metal made of a magnetic material, for example, and the hammer 11 strikes from the bottom to the top. The metal side 19c is attached with the metal side 19c facing down and the ceramic side 19b facing up. At this time, the object to be measured 19 is attracted by the magnetic force of the magnet plate 48 and attracted to the magnet plate 48, and is fixed with an appropriate restraining force.
It is of course possible to hit the ceramic side 19c with the object to be measured 19 turned upside down, with the ceramic side 19c facing down. Since the metal side 19b is adsorbed to the magnet plate 48 through the ceramic with the following thickness, such a test is also possible.

  As shown in FIGS. 9 and 10, the hammer 11 is struck at a distance X with respect to the full length L and at a distance Y with respect to the width W. The distances X and Y are measured objects. 19 The node of its own vibration is obtained in advance and is determined by removing the node. For example, X = 0.3L.

  The vibration node is a position where the amplitude is 0 in the vibration mode of the DUT 19, and removing the vibration node is, for example, a node in any of the first to fifth vibration modes. It means selecting a place that does not become.

  Similarly, the acceleration sensor 13 is attached at a position where the vibration node is removed, and in this embodiment, the acceleration sensor 13 is attached to the plate side 19b of the object 19 to be measured.

  At the time of hitting, as shown in FIG. 11, first, the switch 61 is turned on, the solenoid 33 is activated, and the movable iron core 34 is attracted in the direction of arrow D. As a result, the hammer 11 swings in the direction of arrow C against the tension spring 30 and the tension spring 30 is stretched in the direction of arrow U.

  Subsequently, the switch 61 is turned off, and the attraction is released by the solenoid 33. Then, the tension spring 30 is contracted in the arrow D direction by the spring force, the movable iron core 34 is pulled out in the arrow U direction, the hammer 11 swings in the arrow A direction, and the head 20 moves the pad side 19c of the object 19 to be measured. Blow.

  As shown in FIG. 13, at the moment of impact, the head 20 repels according to the coefficient of restitution between the head 20 and the object 19 to be measured. At this time, the head 20 escapes due to deformation of the coil spring 22, that is, the head Since 20 is vibration-insulated, the vibration on the handle 21 side is not transmitted to the DUT 19 as a reflected wave. Even if the head 20 is swung back and hits the measured object 19 twice, those waveforms are far behind the waveform for about 20 ms immediately after the hit used for analysis in the apparatus of the present invention. There is no effect on pass / fail judgment.

  Further, since the head 20 escapes, the object to be measured 19 is not hit more than necessary, and unnecessary waveform components are not included in the vibration waveform. Even on the side of the object to be measured 19, the elastic body 44 of the pedestal 41 is less susceptible to noise from the upper plate 39 and the like.

The shock wave due to the impact is detected by the acceleration sensor 13 and output to the acceleration amplifier 14 as a voltage signal. The acceleration amplifier 14 appropriately amplifies the signal and then outputs it to the analysis device 15. The analysis device 15 records the signal, and as shown in FIG. 14 (the horizontal axis indicates time (sec) and the vertical axis indicates acceleration (m / sec ² ) due to the hit of the object to be measured), In particular, an initial waveform 51a is obtained for approximately 20 ms immediately after the impact.

The initial waveform contains the most important information for determining the vibration characteristics of the object to be measured 19 and its quality, and is highly valuable. The initial waveform 51a obtained by the present invention is not an interference wave but an original initial vibration wave, and since there is no noise impact waveform, that is, no noise component is mixed in, the ideal waveform gradually attenuates from a large amplitude at the time of impact. Appears as That is, it is possible to use the initial waveform for the analysis for about 20 ms immediately after the impact, which could not be used due to noise mixing in the past.

The analysis device 15 further performs frequency analysis by FFT on the initial waveform 51a, and shows the frequency (Hz) on the horizontal axis and the power spectral density ((m / sec ² ) ² / Hz) on the vertical axis. ), A power spectrum 52 at each frequency arranged in an arithmetic progression is obtained.

As shown in FIG. 18 (the horizontal axis indicates frequency (Hz) and the vertical axis indicates power spectral density ((m / sec ² ) ² / Hz)), a defect 19d exists inside the metal side 19c, If peeling 19e or the like is present on the bonding surface between the metal side 19c and the ceramic side 19b, the peak 52a in the power spectrum 52 becomes dull, the band is widened, the disturbance 52b is generated, or an illegal frequency component 52c appears. Changes also appear in the natural frequency.

As a determination method in the determination device 16, first, a natural frequency of a good product is obtained in advance, and a pass / fail judgment is made based on a change in the natural frequency, and an RMS of the power spectrum 52 is obtained to obtain a standard good product RMS. There is a method for determining the quality of the DUT 19 as compared with the above.

If it is determined that the DUT 19 is a non-defective product, the determination result is shown in FIG. 17 (the horizontal axis indicates frequency (Hz) and the vertical axis indicates power spectral density ((m / sec ² ) ² / Hz)). As shown in FIG. 18, a character 53 of “OK” is displayed on the display device 18, and if it is determined as a defective product, a character 54 of “NG” is displayed on the display device 18 as shown in FIG. 18.

  By using the present invention, it is possible to determine and quantify the hardness of the DUT 19 with high accuracy.

1 to 18 relate to an embodiment of the present invention, and FIG. 1 is a perspective view of an impact test apparatus. It is a longitudinal cross-sectional view of a hit | damage test apparatus. It is a top view of an impact test device. It is a perspective view of a hammer. It is a front view of a hammer. It is a fragmentary longitudinal cross-section which shows the attachment state of the head of a hammer, a coil spring, and a handle. It is a perspective view of a to-be-measured object (special heat-resistant material). It is a perspective view of a base. It is a top view which shows the attachment state of the to-be-measured object to a pedestal, hammering, and the attachment position of an acceleration sensor. It is a longitudinal cross-sectional view which shows the attachment state of the to-be-measured object to a base, hammering, and the attachment position of an acceleration sensor. It is a longitudinal cross-sectional view which shows the state which attached the to-be-measured object to the hit | damage test apparatus, actuated the solenoid, pulled down the head side of the hammer against the tension spring, and was in preparation for hit | damage. FIG. It is a longitudinal cross-sectional view which shows the state which the hammer rock | fluctuated by the spring force of the tension | pulling spring, and the head struck the to-be-measured object by canceling | releasing a solenoid. FIG. 6 is a front view showing a state in which when the head collides with the object to be measured by striking and is repelled, the coil spring is momentarily deformed so that the head escapes and vibration on the handle side is not transmitted to the head side as a reflected wave. . FIG. 6 is a diagram showing that no noise impact waveform is mixed in the initial waveform immediately after hitting from the acceleration sensor on the object to be measured because the hammer head is vibration-insulated. It is a block diagram which shows the connection state of the acceleration amplifier, analysis apparatus, determination apparatus, and display apparatus after an acceleration sensor in a hit | damage test apparatus. It is a diagram which shows the power spectrum obtained by frequency-analyzing an initial waveform with an analyzer. Since the power spectrum obtained by hitting the object to be measured has a sharp peak and less disturbance, the determination device determines that the object to be measured is a non-defective product and indicates that the display device is a good product. It is the longitudinal cross-sectional view of the hit | damage site | part which shows the state by which the character of "OK" was displayed, the diagram of the power spectrum, and the front view of a display apparatus. Since the power spectrum obtained by hitting the object to be measured has a dull peak and many disturbances, the determination device determines that the object to be measured is defective and the display device is defective. FIG. 3 is a longitudinal sectional view of a hitting portion, a power spectrum diagram, and a front view of a display device showing a state in which the letters “NG” indicating “” are displayed. 19 and 20 relate to a conventional example, and FIG. 19 shows a state in which the hammer head is fixed integrally with the handle portion, and when the object to be measured is struck, the hammer cannot escape and the vibration on the handle side is reflected. It is a front view which shows the state currently transmitted to the to-be-measured object as a wave. It is a diagram which shows that a reflected wave becomes a noise shock wave, is mixed in an initial vibration waveform, and becomes an interference wave.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Impact test apparatus 11 Hammer 12 Hammer drive mechanism 13 Acceleration sensor 14 Acceleration amplifier 15 Analysis apparatus 16 Judgment apparatus 18 Display apparatus 19 Measured object 20 Head 21 Handle 22 Coil spring 51 as an example of elastic body 51 Vibration waveform 51 as an example of signal 51a Initial Waveform

Claims (8)

  In a striking test method in which a vibration waveform generated by striking a hammer head is detected by an acceleration sensor, and the vibration waveform is analyzed to judge whether the object to be measured is good or bad, the hammer is subjected to vibration-insulated hammer head. A hammering test method characterized by striking and vibrating a measurement object to prevent generation of a noise shock waveform and mixing of the noise shock waveform into the vibration waveform.   In a striking test method in which a vibration waveform generated by striking a hammer head is detected by an acceleration sensor, and the vibration waveform is analyzed to judge whether the object to be measured is good or bad, the hammer is subjected to vibration-insulated hammer head. Strike and vibrate the measurement object, prevent generation of a noise shock waveform and mixing of the noise shock waveform into the vibration waveform, and analyze the initial vibration waveform immediately after hitting to determine the quality of the measurement object Characteristic impact test method.   In a striking test method in which a vibration waveform generated by striking a hammer head is detected by an acceleration sensor and the vibration waveform is analyzed to determine whether the object to be measured is good or bad, the hammer is subjected to vibration-insulated hammer head. The object to be measured is subjected to impact excitation, the generation of a noise impact waveform and the mixing of the noise impact waveform into the vibration waveform are analyzed, and the initial vibration waveform from about immediately after the impact to about 20 ms is analyzed to analyze the quality of the object to be measured. A hitting test method, characterized in that   A hammer that strikes the object to be measured by the head, an acceleration sensor that detects a vibration waveform generated by the impact, and an analysis and determination device that analyzes the signal from the acceleration sensor and determines the quality of the object to be measured. A hammer test apparatus comprising: a hammer in which the head is vibration-insulated so that vibration of a portion other than the head of the hammer is not transmitted to the workpiece as a reflected wave when the workpiece is hit. A striking test apparatus configured to analyze an initial vibration waveform immediately after striking among signals from a sensor to determine whether the object to be measured is good or bad.   The hammer is vibration-insulated so that the vibration of the part other than the head is not transmitted as a reflected wave to the measurement object when the measurement object is struck, and the measurement object is struck by swinging the hammer. A hammer driving mechanism configured to perform the above operation, an acceleration sensor attached to the object to be measured, an acceleration amplifier connected to the acceleration sensor and amplifying a signal from the acceleration sensor, and the acceleration amplifier connected to the acceleration amplifier An analysis device that analyzes using an initial vibration waveform immediately after hitting among signals from the signal, a determination device that determines the quality of the object to be measured using analysis data obtained by the analysis device, and the determination device A striking test apparatus comprising: a display device for displaying a determination result obtained by the step.   In a hammer for hammering test used for hitting an object to be measured with a head, a part other than the head when the object to be measured is hit by vibrating and insulating between the head and the part other than the head. A hammer for impact test, wherein the vibration is not transmitted as a reflected wave to the object to be measured.   In an impact test hammer used for impact test to strike an object to be measured with a head, an elastic body is disposed between the head and a handle, the head and one end of the elastic body are fixed, The other end of the elastic body and the handle are fixed, and the middle portion of the elastic body is set in a free state to insulate the head and the handle from vibrations. A hammer for impact test, wherein the handle side vibration is configured not to be transmitted as a reflected wave to the object to be measured.   In a hammer for hammering test, which is used for a hammering test and strikes a measured object with a head, a coil spring is disposed between the head and a handle, the head and one end of the coil spring are fixed, The other end of the coil spring and the handle are fixed, and the middle portion of the coil spring is freed to vibrate and insulate the head and the handle. A hammer for impact test, wherein the handle side vibration is configured not to be transmitted as a reflected wave to the object to be measured.

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