JP2004037287A - Impact inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact inspection device capable of performing high-precision impact inspection homogeneously without relying on inspector's experience or sense and not affected by sorrounding noises, etc. <P>SOLUTION: By loading acceleration meters 45 on the upper surface of a supporting plate 44 for elastically supporting with spring members 43a, 43b, 43c and arranging two or more on the surface of a base member 42, and meanwhile hitting to vibrate a fuel cell T with a hammer H in that state, the soundness of the fuel cell as the inspected object is decided based on the correlation between two of them by comparing the vibration frequency, the phase with respect to a reference and the vibration mode, etc. at that time with the data of the good fuel cell T. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an impact inspection device, and is particularly useful when applied to inspect a defect of a fuel cell, a concrete test piece, or the like based on a vibration when these are hit.
[0002]
[Prior art]
A fuel cell is a multilayer structure in which a copper plate and a rimple material are laminated by bonding, and it is necessary to inspect each layer for defects such as poor bonding. For this reason, hit inspection has been conventionally performed to inspect an inspection object such as a fuel cell. Specifically, a fuel cell to be inspected is placed on a workbench, and the inspector hits the fuel cell with a hammer and listens to the sound of the hit to determine pass / fail.
[0003]
On the other hand, Japanese Patent Application Laid-Open No. Sho 61-23966 discloses that a test sample such as a casting is hit, a sound generated by the hit is collected by a microphone, passed through a band-pass filter, and based on output data from the band-pass filter. There is disclosed an automatic sensitivity inspection apparatus for determining the good / defective rank of a sample. Japanese Patent Application Laid-Open No. Hei 6-34430 discloses a sound quality in which a sound to be evaluated generated from an automobile part or the like is detected by a microphone, and the detected sound is evaluated based on a membership function obtained in advance by a sensitivity test. An evaluation device is disclosed.
[0004]
[Problems to be solved by the invention]
In the impact inspection in which the inspector strikes the fuel cell etc. and judges the impact sound, the judgment of the defect depends on the experience, sensitivity, etc. of the individual, so the evaluation is not quantitative and the results may vary. There's a problem.
[0005]
On the other hand, in the inspection apparatus described in JP-A-61-23966 and JP-A-6-34430, since a striking sound is detected by a microphone, the judgment result is affected by the influence of ambient noise such as background noise. There is a problem that accuracy is reduced.
[0006]
The present invention has been made in consideration of the above-described problems of the related art, and can perform a high-precision inspection that is uniform without being influenced by ambient noise and the like without relying on the experience and sensibility of the inspector. An object is to provide an excellent impact inspection device.
[0007]
[Means for Solving the Problems]
The configuration of the present invention that achieves the above object has the following features.
[0008]
1) It has a plurality of elastic members disposed on the surface of a flat base member, a support plate elastically supported by each elastic member, and an accelerometer mounted on the upper surface of each support plate. A sensor unit configured to place an inspection object,
The test object is vibrated by hitting it with a hammer or the like in a state where the test object is supported by being brought into contact with each accelerometer of the sensor unit. Signal processing means for detecting characteristics, phase characteristics, and optionally detecting a vibration mode at a specific frequency,
The frequency characteristics and the phase characteristics when the reference inspection object whose soundness is guaranteed as described above are vibrated as described above, or the frequency characteristics, the reference data based on the phase characteristics and the vibration mode, and the inspection object to be measured in the same manner. Comparing the frequency characteristics and the phase characteristics when the vibration is applied, or the frequency characteristics, the phase characteristics, and the actually measured data based on the vibration mode, and determining whether the inspection object is good or bad based on the correlation between the two data. thing.
[0009]
2) It has a plurality of elastic members disposed on the surface of a base member which is a flat plate, a support plate elastically supported by each elastic member, and a load meter mounted on the upper surface of each support plate. A sensor unit configured to place an inspection object,
The test object is vibrated by hitting it with a hammer or the like in a state where the test object is supported by being brought into contact with each load cell of the sensor unit, and the output signal of each load cell obtained by this is processed to process the frequency. Signal processing means for detecting the characteristic, the phase characteristic and the weight of the inspection object, and further optionally detecting a vibration mode at a specific frequency,
When the reference test object whose soundness is guaranteed is vibrated as described above, the frequency characteristics, the phase characteristics, and the weight, or the reference data based on the frequency characteristics, the phase characteristics, the weight, and the vibration mode, and the test to be measured. The frequency characteristics, the phase characteristics and the weight when the target object is similarly vibrated, or the frequency characteristics, the phase characteristics, the measured data based on the weight and the vibration mode are compared, and based on the correlation between the two data, the inspection target is determined. Determining means for determining the quality of the product.
[0010]
3) In the impact inspection device described in 1) or 2) above,
A base member having a concave portion at each position where an accelerometer or a load meter is provided,
A base piece that is a small piece formed to fit into the recess, an elastic member disposed on the surface of the base piece, a support plate elastically supported by the elastic member, and an acceleration placed on the upper surface of the support plate A sensor unit having a load meter or a load cell.
[0011]
4) In the impact inspection device according to any one of 1) to 3) above,
The tip of the accelerometer or the load meter is a cone, and the tip of the cone is configured to support the inspection object in point contact from below the inspection object.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
<First embodiment>
FIG. 1 is a perspective view showing the impact inspection device according to the first embodiment of the present invention. The impact inspection device 1 includes a base member 2, an elastic portion 4 provided on the base member 2, and five accelerometers 6a, 6b, 6c, 6d, which are sensors attached to the four corners and the center of the elastic portion 4. 6e, and a signal processing device 8 for processing signals detected by the accelerometers 6a to 6e. The elastic portion 4 provided on the base member 2 is formed of any appropriate elastic member such as a rubber plate, a sponge, or the like. The material, thickness and the like of the elastic member 4 are appropriately selected according to the inspection object. The five accelerometers 6a to 6e are mounted on the elastic part 4 so that the test object can be supported on them. The arrangement and number of the accelerometers 6a to 6e can be arbitrarily changed according to the application. Further, parts other than the elastic portion 4 of the base member 2 may be omitted, and the entire base member 2 may be formed of an elastic member.
[0014]
The outputs of the accelerometers 6a to 6e are connected to a signal processing device 8. The signal processing device 8 includes a frequency analysis unit 12 for frequency-analyzing the output signals of the accelerometers 6a to 6e, and a determination unit 14 for determining the presence or absence of a defect in the inspection target based on the analysis result of the frequency analysis unit 12. And a display unit 10 for displaying the determination result of the determination unit 14.
[0015]
Here, the operation of the impact inspection device 1 according to the first embodiment will be described with reference to FIGS.
[0016]
FIG. 2 is an explanatory view conceptually showing a mode of a hit test using the hit inspection device 1. First, the impact inspection device 1 is installed on the work desk D, and the fuel cell T to be inspected is placed on each accelerometer 6 attached to the elastic portion 4 of the impact inspection device 1. When the test object is supported on each accelerometer 6, the elastic portion 4 to which the accelerometer 6 is attached is deformed by a certain amount due to the weight of the test object, and the test object is supported at that position. Next, the inspector strikes a predetermined position of the fuel cell T with the hammer H to vibrate the fuel cell T. The position at which the inspection target is hit is set at an appropriate position such as a corner or a center of the inspection target according to the application so that a dominant frequency described later can be clearly detected.
[0017]
The fuel cell T whose vibration is excited by the vibration deforms and vibrates on each accelerometer 6. For example, when a portion of the fuel cell T supported by the accelerometer 6a vibrates downward, the accelerometer 6a is pressed downward by the fuel cell T, and the elastic part 4 is deformed by the force, and the accelerometer 6a moves downward. Moved. Conversely, when the fuel cell T vibrates upward, the elastic portion 4 that has been deformed downward due to its own weight is restored to its original shape, and the accelerometer 6a is pressed against the fuel cell T by the elastic portion 4. Can be Preferably, the material and thickness of the elastic portion 4 are selected such that the accelerometer 6 is in contact with the inspection object over the entire cycle of the vibration of the inspection object. Thus, each accelerometer 6 vibrates up and down according to the deformation and vibration of the fuel cell T while being in contact with the fuel cell T. The output signal of each accelerometer 6 is sent to a signal processing device 8.
[0018]
FIG. 3A is a flowchart of signal processing at the time of a reference data collection operation performed to obtain reference data of a sound inspection target before an actual impact test is performed, and FIG. 6 is a flowchart of signal processing when performing a hit test.
[0019]
When acquiring the reference data, the fuel cell T, which has been confirmed to be free from defects by a conventional impact inspection method or the like, is mounted on an impact inspection device and impact is performed. Otherwise, the procedure is the same as that of the actual impact test. That is, vibration is generated by striking a sound fuel cell T, and the resulting time-dependent waveform of the vibration is detected by the five accelerometers 6a to 6e.
[0020]
In step S1, the frequency analysis unit 12 built in the signal processing device 8 acquires those time history waveforms.
[0021]
Next, in step S2, the frequency analysis unit 12 calculates the frequency spectrum of each time history waveform. For the calculation of the frequency spectrum, an FET operation (fast Fourier operation) well known to those skilled in the art can be used.
[0022]
In step S3, a dominant frequency at which each frequency spectrum indicates a peak is extracted. FIGS. 4A to 4E show frequency spectra of time history waveforms obtained by the accelerometers 6a to 6e, respectively. Here, the characteristics of FIG. 4A correspond to the accelerometer 6a, and similarly, the characteristics of FIG. 4B correspond to the accelerometer 6b, the characteristics of FIG. 4D correspond to the characteristics shown in FIG. The frequency spectrum at the four corners of the fuel cell T shown in FIGS. 4A to 4D has a dominant frequency at about 1750 Hz, and the frequency spectrum at the center of the fuel cell T shown in FIG. Has a dominant frequency.
[0023]
In step S4, these dominant frequencies are stored as reference data in the discriminating unit 14 built in the signal processing device 8. Thus, the reference data acquisition process ends.
[0024]
At this time, preferably, the natural frequency (the natural frequency of the rigid body mode) defined by the mass of the inspection object and the spring characteristics of the elastic portion 4 is sufficiently lower than the dominant frequency to be measured. By selecting the material and thickness of the elastic portion 4, the impact inspection device is configured.
[0025]
Next, a data processing procedure in an actual impact test will be described with reference to FIG. In the actual impact test, first, the fuel cell T to be inspected is mounted on the impact inspection device 1 and is impacted with the hammer H. The processing from the acquisition of the striking waveform data in step S11 in FIG. 3B to the determination of the dominant frequency in step S13 is the same as steps S1 to S3 in FIG.
[0026]
Next, in step S14, the dominant frequency of the reference data stored in the determining unit 14 in step S4 of FIG. 3A and the dominant frequency of the fuel cell T to be inspected extracted in step S13 are determined by the determining unit. 14 are compared. If the dominant frequencies of the respective frequency spectra match, the process proceeds to step S15, and the display unit 10 displays that the fuel cell T has no defect.
[0027]
On the other hand, if any one of the dominant frequencies does not match the reference data, the process proceeds to step S16, and a message indicating that the fuel cell T is defective is displayed. As an example, in the fuel cell T having a defect such as poor adhesion, the dominant frequency existing at 1750 Hz is reduced to about 1500 Hz, and the dominant frequency existing at 3000 Hz is reduced to about 2300 Hz. In this embodiment, when the dominant frequency of 1750 Hz falls to 1550 Hz or less, or the dominant frequency of 3000 Hz falls to 2350 Hz or less, it is determined that there is a defect. However, the determination method and the frequency used as the threshold can be appropriately determined according to the inspection target or the like.
[0028]
According to the impact inspection apparatus of the present embodiment, it is possible to obtain a uniform inspection result without depending on the experience and sensitivity of the inspector, and to perform the inspection with high accuracy even in an environment where ambient noise is large. Can be. Further, since the vibration of the inspection object is measured by a plurality of accelerometers, a local defect of the inspection object can be detected. In addition, according to the present embodiment, it is not necessary to attach an accelerometer to an inspection target, as in a vibration test generally performed using an accelerometer, and the inspection can be performed quickly.
[0029]
<Second embodiment>
Next, with reference to FIG. 5, an impact inspection device according to a second embodiment of the present invention will be described. As shown in the drawing, the impact inspection device 20 according to the present embodiment uses a load meter as a sensor instead of the accelerometers 6a to 6e shown in FIG. 1 and has a first point in that the base member has no elastic portion. Although the third embodiment is different from the first embodiment, most other configurations are the same as those of the first embodiment. Therefore, the same portions as those in FIG. 1 are denoted by the same reference numerals, and overlapping descriptions including operations and effects are omitted.
[0030]
As shown in FIG. 5, the impact inspection device 20 according to the present embodiment includes a base member 22, five load cells 24 attached to the four corners and the center of the base member 22, and a signal processing connected to each load cell 24. Device 8.
[0031]
Next, the operation of the second embodiment will be described. First, similarly to the first embodiment, the fuel cell T to be inspected is placed on each load cell 24, and a predetermined position is hit with a hammer. Vibration is excited in the inspection object by the impact, and when a part of the fuel cell T vibrates and deforms downward, the force acting on the load cell supporting the part increases. Conversely, when a part of the fuel cell T vibrates or deforms upward, the force acting on the load cell supporting that part decreases, and may become zero at the minimum. In this manner, the time history waveform corresponding to the vibration of the inspection object is detected by the load meter.
[0032]
At this time, since the position at which each load cell 24 supports the inspection object moves only by the amount of deformation of the load cell 24 and the base member 22, the amount of movement is very small. Therefore, the vibration amplitude of the inspection object is generally smaller than that in the first embodiment. The processing of the signal detected by each load cell 24 is the same as in the first embodiment.
[0033]
In this embodiment, since the dominant frequency is grasped by a change in load, the test object does not need to be floated by an elastic body such as rubber or sponge, and can be applied to a heavy test object.
[0034]
<Third embodiment>
Next, an impact inspection device 30 according to a third embodiment of the present invention will be described with reference to FIGS. The impact inspection device 30 according to the third embodiment supports an inspection target on an elastic portion 34 provided on a base member 32, and the vibration of the inspection target is detected by a non-contact sensor. This is different from the first embodiment. However, since many parts are the same as those of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals, and overlapping descriptions including operations and effects are omitted.
[0035]
FIG. 6A is a perspective view illustrating the impact inspection device 30 according to the third embodiment, and FIG. 6B is a cross-sectional view taken along line bb of FIG. 6A. As shown in the figure, the impact inspection device 30 includes a base member 32 provided with five concave portions 38 for mounting sensors, an elastic portion 34 provided in the base member 32, and a mounting member in each of the concave portions 38. And a signal processing device 8 connected to each of the non-contact sensors.
[0036]
Here, as the non-contact sensor 36, a laser displacement meter, a laser vibrometer, a capacitance type displacement meter, an eddy current type displacement meter, or the like can be used depending on the application. The elastic portion 34 provided on the upper portion of the base member 32 is made of sponge, flexible rubber, or the like. The entire surface of the fuel cell T to be inspected except for the portion that is hollowed out to form the concave portion 38 is provided with the elastic portion 34. It is configured to support. The thickness and material of the elastic portion 34 are determined so that a predetermined gap is formed between the non-contact sensor and the test object when the test object is placed on the elastic portion.
[0037]
Next, the operation of the present embodiment will be described. First, the fuel cell T to be inspected is placed on the elastic portion 34 of the base member 32. At this time, the fuel cell T is supported with the elastic portion 34 deformed by a predetermined amount due to the weight of the fuel cell T. Next, when the fuel cell T is hit, the fuel cell T deforms and vibrates on the elastic portion 34. Due to this vibration, the distance between the fuel cell T and the non-contact type sensor 36 is deformed, and a signal corresponding to this change is detected by each non-contact type sensor 36. Since the signal processing procedure by the signal processing device 8 is the same as that of the first embodiment, the description is omitted.
[0038]
In the present embodiment, since the sensor and the inspection object are not in contact with each other, the influence of the weight of the sensor and the influence of the contact of the sensor can be eliminated, and the determination can be performed with high accuracy. Further, in this embodiment, since almost the entire surface of the inspection target is supported by the elastic portion, the pressure acting on the inspection target is small, and the inspection target is not damaged.
[0039]
<Fourth embodiment>
FIGS. 7A and 7B are views showing a hit inspection apparatus according to a fourth embodiment of the present invention, in which FIG. 7A is a perspective view of a sensor unit in which a detection target is placed, and FIG. FIG. 2C is a perspective view illustrating the extracted sensor, and FIG. 2C is a front view illustrating the extracted sensor. As shown in the drawing, the impact inspection device 41 according to the present embodiment has a plurality of (in the present embodiment, nine) sensor units I distributed on the surface of a base member 42 which is a flat plate. The sensor unit I has spring members 43a, 43b, and 43c, which are elastic members disposed upright on the surface of the base member. The spring members 43a, 43b, and 43c form a set of three, and the upper end thereof elastically supports the disk-shaped support plate 44 from below. The accelerometer 45, which is a sensor in the case of the present embodiment, is mounted on the upper surface of each support plate 44, and its tip is a cone (cone). The fuel cell T is configured to be supported in point contact with the fuel cell T from below. Here, the cone can be easily formed, for example, by fixing a conical cap 45a to the main body of the accelerometer 45, which is a cylindrical body 45b.
[0040]
In the present embodiment, the fuel cell T is placed in contact with the cap 45a of the accelerometer 45 of the sensor unit I shown in FIG. FIG. 7A shows a state where the fuel cell T is mounted. In this state, the predetermined position of the fuel cell T is hit with the hammer H to vibrate. As a result, the fuel cell T swings not only in the vertical direction but also in the horizontal direction, but the three-point supported spring members 43a to 43c absorb the swing and move the fuel cell T parallel to the surface of the base plate 42. . As a result, the accelerometer 45 can detect the acceleration due to the vibration generated in the fuel cell T with high accuracy in combination with the effect of the point contact support by the cap 45a.
[0041]
The output signal of each accelerometer 45 is sent to a signal processing system and processed according to a predetermined procedure. FIG. 8 is a block diagram showing a signal processing system according to this embodiment. As shown in FIG. ₁ Are input to the signal processing / judgment unit 48 via the amplifiers 46 and the filters 47 provided correspondingly. At the same time, the output signal S of the hammer H load cell ₂ Is also input to the signal processing / determination unit 48 via the amplifier 46 and the filter 47. Here, the filter 47 is a band pass for extracting a component of a predetermined frequency band from the output signal of the accelerometer 45. The signal processing / judgment unit 48 processes each input signal to judge the quality of the fuel cell T to be inspected. The signal processing / judgment unit 48 can be suitably constituted by a personal computer, for example. The specific procedure of the signal processing and the specific procedure of the pass / fail determination processing in the signal processing / determination section 48 are as follows.
[0042]
FIG. 9 is a flowchart showing a data processing procedure in the signal processing / determination section 48. As shown in the drawing, also in this embodiment, first, a reference fuel cell T, which is an inspection object whose soundness is guaranteed, is hit with a hammer H to vibrate, and the output signal of each accelerometer 45 at this time is excited. To analyze. That is, the fuel cell T whose soundness is guaranteed is hit (see step S21), and the hitting waveform data generated thereby is obtained (see step S22). Next, the frequency analysis of the impact waveform data is performed. In the present embodiment, not only the calculation of the frequency but also the calculation of the phase is performed (see step S23). This phase relationship is also to improve the determination accuracy as an element for determining the quality of the fuel cell T to be inspected. Incidentally, in this embodiment, since the output signal of the load meter built in the hammer H for detecting the impact acting on the hammer H is also inputted and processed at the same time, the output signal of each accelerometer 45 based on this is used. Can be detected. Note that such a phase relationship does not necessarily need to be based on an impact waveform acting on the hammer H. For example, one of the accelerometers 45 may be used as a reference sensor to calculate the phase relationship with respect to the output signal. In this case, it is not necessary to detect the impact acting on the hammer H.
[0043]
Further, in the present embodiment, a vibration mode indicating the state of vibration of each part of the fuel cell T due to the vibration is also calculated (see step S24). The data calculated in the processing of steps S23 and S24 is stored in a database as reference data (see step S25).
[0044]
After converting the reference data into a database as described above, the same excitation is performed on the fuel cell T to be actually inspected, and actual measurement data is created by the same processing as steps S21 to S24 (see step S26). Through (see step S29).
[0045]
Thereafter, the reference data in the database and the actually measured data are compared (see step S30). If they match, it is determined that they are sound (see step S31), and if they do not match, it is determined that there is a defect. (See step S32).
[0046]
FIGS. 10 to 12 show frequency characteristics, phase characteristics, and vibrations obtained based on the output signals of the accelerometers 45 when different impact points of the fuel cell T, which is the inspection object, are struck with the hammer H and vibrated. It is a characteristic view showing a mode. In each figure, nine frequency characteristics and phase characteristics arranged in order from the upper left correspond to the analysis results of the output signals of the accelerometer 45 arranged in order from the upper left shown in FIG. 7B. These are reference data based on the fuel cell T whose soundness is guaranteed. The vibration mode shown in the upper part of FIG. 10 is a vibration mode related to the vibration frequency E (Hz) when the strike point indicated by the arrow in the figure is hit, and the vibration mode of the fuel cell T corresponding to the position of each accelerometer 45 is shown. This indicates that each point vibrates between the points indicated by white circles and black circles in the figure. The vibration mode based on data obtained by hitting the same hitting point and collecting the vibration frequency E (Hz) matches that of FIG. 10 if the fuel cell T is sound. As described above, the accuracy of the quality determination is remarkably improved by using the vibration mode as an element of the quality determination together with the phase. 11 and 12 also show characteristics according to FIG. 10, but the case of FIG. 11 is a vibration mode related to the frequency F (Hz) when the hit point indicated by the arrow in FIG. 11 is hit. The case of 12 is a vibration mode relating to the vibration frequency G (Hz) when the hit point indicated by the arrow in the figure is hit.
[0047]
<Fifth embodiment>
FIGS. 13A and 13B are views showing a hit inspection device according to a fifth embodiment of the present invention, wherein FIG. 13A is a perspective view of a sensor unit in which a detection target is mounted, and FIG. It is a perspective view which extracts and shows. As shown in the drawing, the impact inspection device 51 according to the present embodiment includes the spring members 43a, 43b, 43c, the support plate 44, and the accelerometer 45 of the sensor unit I according to the fourth embodiment shown in FIG. It is integrated and unitized on a base piece 52 which is a small piece on a disk. At the same time, the base member 50 is formed with a concave portion 50a at each position where the accelerometer 45 is disposed, and the base piece 52 of the unit is fitted into each concave portion 50a. A plurality of such units and the base member 50 constitute the sensor section II.
[0048]
Therefore, in the present embodiment, by appropriately selecting the number of units fitted into the concave portion 50a, it is possible to configure the impact inspection device II according to the size of the inspection object. That is, it is possible to use the same type of impact inspection apparatus for a plurality of types of fuel cells T having different sizes. The other components such as a signal processing system are exactly the same as those of the fourth embodiment. Therefore, duplicate description will be omitted.
[0049]
<Sixth Embodiment>
FIGS. 14A and 14B are views showing a strike inspection device according to a sixth embodiment of the present invention, wherein FIG. 14A is a perspective view of a sensor portion showing a state where a detection target is placed, and FIG. FIG. 2C is a perspective view illustrating the extracted sensor, and FIG. 2C is a front view illustrating the extracted sensor. The impact inspection device 61 according to the present embodiment is different from the fourth and fifth embodiments only in that the sensor of the sensor unit III is constituted by the load meter 65. Therefore, the same portions as those of the fourth and fifth embodiments are denoted by the same reference numerals, and duplicate description will be omitted.
[0050]
According to the present embodiment, since the load meter 65 is used as a sensor, it is possible to measure not only the frequency, phase, and vibration mode of the vibration waveform obtained by hitting the inspection target, but also the weight of the inspection target. Therefore, this weight can also be used as an element of the quality judgment.
[0051]
FIG. 15 is a flowchart showing a data processing procedure in the impact inspection device 61 according to this embodiment. As shown in the figure, in the present embodiment, the weight of the inspection object is also used as an element of the pass / fail judgment, so that the processing of calculating the weight of the inspection object is added at the time of collecting the sound data and the inspection data, respectively. (See steps S33 and S34.) Therefore, the reference data and the measured data are compared with the frequency, phase, and vibration mode, as well as the weight of the fuel cell T as an element (see step S35). Are exactly the same as those of the fourth and fifth embodiments, so that the same parts as those in FIG.
[0052]
In the fourth to sixth embodiments, the vibration mode as well as the frequency characteristic and the phase characteristic are taken into consideration as the data for judging the quality, but this is not always necessary. When sufficient judgment accuracy can be obtained, the vibration mode can be omitted from the judgment element. However, it is clear that better judgment accuracy is guaranteed when the vibration mode is also considered.
[0053]
The preferred embodiments of the present invention have been described above. However, various modifications may be made to the disclosed embodiments without departing from the scope or spirit of the present invention within the scope of the technical matters described in the claims. Can be. In particular, the impact inspection device of the present invention can inspect any portable inspection object other than the fuel cells exemplified in the above embodiments. Further, the purpose of the inspection need not always be to find a defect, and the impact inspection apparatus of the present invention can be used for ranking or sorting products. Further, the vibration need not necessarily be impact vibration by a hammer, and any vibration method such as impact vibration by an electric vibration machine or random vibration can be adopted.
[0054]
【The invention's effect】
As specifically described with the above embodiments, the invention described in [Claim 1] is directed to an elastic member provided on a surface of a base member which is a flat plate, and a support plate elastically supported by each elastic member. And a sensor unit having an accelerometer mounted on the upper surface of each support plate and configured to mount an inspection object on each accelerometer, and contacting the inspection object with each accelerometer of the sensor unit. The test object is vibrated by hitting it with a hammer or the like in a state of being supported and processed, and the output signal of each accelerometer obtained thereby is processed to detect its frequency characteristic and phase characteristic, and further, in some cases, a specific Signal processing means for detecting a vibration mode at a frequency, and the frequency characteristic and the phase characteristic, or the frequency characteristic, the phase characteristic and the vibration when the reference test object whose soundness is guaranteed is vibrated as described above. The reference data based on the data and the frequency characteristics and the phase characteristics when the test object to be measured is similarly vibrated, or the measured data based on the frequency characteristics, the phase characteristics, and the vibration mode are compared, and a correlation between the two data is obtained. A determination unit that determines the quality of the inspection target based on the relationship,
Not only can a uniform inspection result be obtained without relying on the experience and sensibility of the inspector, but also the inspection can be performed with high accuracy even in an environment with large ambient noise.
Further, since the vibration of the inspection object is measured by a plurality of accelerometers, a local defect of the inspection object can be detected. Further, since each accelerometer is individually elastically supported, it is possible to detect a vibration waveform that faithfully follows the vibration of the inspection object, thereby improving the accuracy of the quality determination of the inspection object. be able to.
Further, according to the present invention, not only the vibration frequency of the inspection object but also the phase characteristics are used as elements in the quality judgment, so that the accuracy of the quality judgment can be more reliably improved. In addition, when the vibration mode is also used as an element of the quality judgment, the accuracy of the quality judgment is dramatically improved.
[0055]
The invention described in [Claim 2] is characterized in that a plurality of elastic members are provided on the surface of a base member which is a flat plate, a support plate elastically supported by each elastic member, and a load placed on the upper surface of each support plate. And a sensor unit configured to place the test object on each load cell, and hammering the test object with the test object in contact with and supported by each load meter of the sensor unit. Vibration by hitting with etc., and processing the output signal of each load cell obtained thereby to detect its frequency characteristics, phase characteristics and the weight of the inspection object, and furthermore, in some cases, the vibration mode at a specific frequency A signal processing means for detecting, based on the frequency characteristics, phase characteristics and weight, or the frequency characteristics, phase characteristics, weight and vibration mode when the reference test object whose soundness is guaranteed is vibrated as described above. Zu The reference data and the frequency characteristics, the phase characteristics and the weight when the test object to be measured is similarly vibrated, or the frequency characteristics, the phase characteristics, the measured data based on the weight and the vibration mode are compared, and both data are compared. A determination unit for determining the quality of the inspection target based on the correlation,
In addition to the functions and effects of the invention described in [Claim 1], the weight of the inspection object can also be used as an element of the quality determination, so that the determination accuracy can be further improved.
[0056]
The invention described in [Claim 3] is characterized in that, in the impact inspection device according to [Claim 1] or [Claim 2], a base member having a concave portion formed at each position where an accelerometer or a load meter is provided; A base piece that is a small piece formed to fit into the recess, an elastic member disposed on the surface of the base piece, a support plate elastically supported by the elastic member, and an acceleration placed on the upper surface of the support plate And a sensor unit equipped with a load cell
In addition to the functions and effects of the inventions described in [Claim 1] and [Claim 2], by appropriately selecting the number of units to be fitted into the concave portions, it is possible to provide a hitting inspection device according to the size of the inspection object. Can be configured. In other words, it is possible to achieve a common impact inspection apparatus for a plurality of types of inspection objects having different sizes.
[0057]
According to the invention described in [Claim 4], in the impact testing device according to any one of [Claim 1] to [Claim 3], the tip of the accelerometer or the load meter is a cone. Since the tip of the cone is configured to support the test object in point contact from below the test object,
In addition to the functions and effects of the invention described in [Claim 1] to [Claim 3], the object to be inspected can be supported at a point from below, so that the inspection can be performed with high accuracy by following the vibration exactly. The vibration waveform of the object can be detected.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an impact inspection device according to a first embodiment of the present invention.
FIG. 2 is an explanatory view conceptually showing a mode of a blow test by the blow test apparatus shown in FIG. 1;
FIG. 3 is a flowchart showing a data processing procedure in the impact inspection device shown in FIG. 1;
4 is a characteristic diagram showing an example of a frequency spectrum measured by the impact inspection device shown in FIG.
FIG. 5 is a perspective view showing a strike inspection device according to a second embodiment of the present invention.
FIGS. 6A and 6B are views showing a hit inspection apparatus according to a third embodiment of the present invention, wherein FIG. 6A is a perspective view thereof, and FIG. 6B is a sectional view taken along line bb.
FIGS. 7A and 7B are views showing a hitting inspection device according to a fourth embodiment of the present invention, wherein FIG. 7A is a perspective view of a sensor unit in a state where a detection target is placed, and FIG. FIG. 3C is a perspective view showing only one of the sensors, and FIG. 4C is a front view showing only one of the sensors.
8 is a block diagram showing a signal processing system of the impact inspection device shown in FIG.
9 is a flowchart showing a data processing procedure in the impact inspection device shown in FIG.
FIG. 10 is a characteristic diagram showing a frequency characteristic, a phase characteristic, and a vibration mode obtained based on an output signal of each accelerometer when a first excitation point of the inspection object is excited.
FIG. 11 is a characteristic diagram showing a frequency characteristic, a phase characteristic, and a vibration mode obtained based on an output signal of each accelerometer when a second excitation point of the inspection object is excited.
FIG. 12 is a characteristic diagram showing a frequency characteristic, a phase characteristic, and a vibration mode obtained based on an output signal of each accelerometer when a third excitation point of the inspection object is excited.
FIGS. 13A and 13B are views showing a hitting inspection device according to a fifth embodiment of the present invention, wherein FIG. 13A is a perspective view of a sensor portion of the impact detection device mounted thereon, and FIG. FIG. 4 is a perspective view showing only units extracted.
FIGS. 14A and 14B are views showing a hitting inspection device according to a sixth embodiment of the present invention, wherein FIG. 14A is a perspective view of a sensor unit in a state where a detection target is placed, and FIG. FIG. 3C is a perspective view showing only one of the sensors, and FIG. 4C is a front view showing only one of the sensors.
FIG. 15 is a flowchart showing a data processing procedure in the impact inspection device shown in FIG.
[Explanation of symbols]
I, II, III sensor unit
H hammer
T fuel cell
41, 51, 61 Impact inspection device
42, 50 Base member
43a, 43b, 43c spring member, 44 support plate
45 accelerometer
45a cap
52 Base piece
65 load cell

Claims (4)

It has a plurality of elastic members arranged on the surface of a flat base member, a support plate elastically supported by each elastic member, and an accelerometer mounted on the upper surface of each support plate. A sensor unit configured to place an object,
The test object is vibrated by hitting it with a hammer or the like in a state where the test object is supported by being brought into contact with each accelerometer of the sensor unit. Signal processing means for detecting characteristics, phase characteristics, and optionally detecting a vibration mode at a specific frequency,
The frequency characteristics and the phase characteristics when the reference inspection object whose soundness is guaranteed as described above are vibrated as described above, or the frequency characteristics, the reference data based on the phase characteristics and the vibration mode, and the inspection object to be measured in the same manner. Comparing the frequency characteristics and the phase characteristics when the vibration is applied, or the frequency characteristics, the phase characteristics, and the actually measured data based on the vibration mode, and determining whether the inspection object is good or bad based on the correlation between the two data. An impact inspection device characterized by the above-mentioned. It has a plurality of elastic members arranged on the surface of a base member that is a flat plate, a support plate elastically supported by each elastic member, and a load meter placed on the upper surface of each support plate, and an inspection object is placed on each load meter. A sensor unit configured to place an object,
The test object is vibrated by hitting it with a hammer or the like in a state where the test object is supported by being brought into contact with each load cell of the sensor unit, and the output signal of each load cell obtained by this is processed to process the frequency. Signal processing means for detecting the characteristic, the phase characteristic and the weight of the inspection object, and further optionally detecting a vibration mode at a specific frequency,
When the reference test object whose soundness is guaranteed is vibrated as described above, the frequency characteristics, the phase characteristics, and the weight, or the reference data based on the frequency characteristics, the phase characteristics, the weight, and the vibration mode, and the test to be measured. The frequency characteristics, the phase characteristics and the weight when the target object is similarly vibrated, or the frequency characteristics, the phase characteristics, the measured data based on the weight and the vibration mode are compared, and based on the correlation between the two data, the inspection target is determined. And a judging means for judging pass / fail of the hitting inspection device. In the impact inspection device according to [claim 1] or [claim 2],
A base member having a concave portion at each position where an accelerometer or a load meter is provided,
A base piece that is a small piece formed to fit into the recess, an elastic member disposed on the surface of the base piece, a support plate elastically supported by the elastic member, and an acceleration placed on the upper surface of the support plate And a sensor unit having a load meter. In the impact inspection apparatus according to any one of [Claim 1] to [Claim 3],
A tip test of an accelerometer or a load meter is a cone, and the tip of the cone is configured to support the test object in point contact with the test object from below the test object. apparatus.

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