JP2002333437A - Impact inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact inspection device capable of performing automatically homogeneous impact inspection even in a wide-range inspection. SOLUTION: This impact inspection device 1 is characterized by having a truck 2 for running along the surface of an inspection object T, a striking means 6 mounted on the truck, for striking the inspection object, a measuring means 8 mounted on the truck, for measuring a sound wave or a vibration excited by striking, a characteristic extraction means 20 for extracting the characteristic value of a prescribed vibration waveform from the vibration waveform measured by the measuring means, a comparison means 22 for comparing the characteristic value extracted by the characteristic extraction means with a prescribed threshold, and a determination means 24 for performing determination on the inspection object based on the comparison result acquired by the comparison means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a tunnel, a bridge,
The present invention relates to an impact inspection device for detecting an inspection object defect or the like by hitting an inspection object such as a building or various machines.

[0002]

2. Description of the Related Art In recent years, the existence of defects such as cold joints in concrete structures such as tunnels has become a social problem. In a conventional impact inspection, a defect inspector hits the wall or ceiling of the tunnel with a hammer and hears the impact sound to determine the presence or absence of the defect. At this time,
The inspector needs to inspect a high place of a wall surface or a wide range of wall surfaces while moving in a tunnel or the like and sequentially moving in a tunnel.

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, passed through a band-pass filter, and output data from the band-pass filter is output. There is described an automatic responsiveness inspection apparatus that determines a good / defective rank of a sample based on the result. 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 described.

[0004]

In a conventional impact test in which an inspector hits a wall or the like, a large burden is imposed on the inspector in a wide range of inspections. Since the presence or absence of a defect is determined on the basis of the above, there is a problem that the inspection result tends to vary.

In the inspection apparatus described in JP-A-61-23966 and JP-A-6-34430, it is possible to avoid the variation in the inspection result due to the judgment by the inspector. There is a problem that the accuracy of the determination result is reduced due to the influence of ambient noise such as background noise.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an impact inspection apparatus capable of performing a uniform impact inspection even in a wide range of inspections. It is a second object of the present invention to provide an impact inspection device that is less susceptible to ambient noise such as background noise.

[0007]

In order to solve the above-mentioned problems, a hit inspection apparatus according to the present invention includes a cart for traveling along the surface of an object to be inspected, and a bogie mounted on the cart and provided with the object to be inspected. Impact means for hitting, a measuring means attached to the bogie, for measuring sound waves or vibrations excited by the hitting, and a characteristic value of a predetermined vibration waveform from the vibration waveform measured by the measuring means. A characteristic extracting means for extracting, a comparing means for comparing the characteristic value extracted by the characteristic extracting means with a predetermined threshold value, and a judgment on the inspection object based on a comparison result by the comparing means. And determination means for performing the determination.

According to this configuration, the truck of the impact inspection device according to the present invention is moved on the surface of the inspection object to be inspected. The striking means attached to the cart strikes the inspection object while traveling on the inspection object. The sound wave excited by the impact or the vibration of the inspection object is measured by measuring means attached to the cart. The characteristic extracting means extracts a predetermined characteristic value from the vibration waveform measured by the measuring means. The comparing means compares the characteristic value extracted by the characteristic extracting means with a predetermined threshold. The determining means makes a determination on the inspection object based on a comparison result by the comparing means. With this configuration, a uniform impact inspection can be performed even in a wide range of inspections.

The characteristic value of the vibration waveform extracted by the characteristic extracting means is calculated based on the amplitude of the time history vibration waveform, the amplitude of the frequency spectrum of the vibration waveform, or the dominant frequency of the frequency spectrum of the vibration waveform. Is good. Further, the measuring means may be a directional microphone arranged to detect a sound near the hitting point by the hitting means. With this configuration, it is less likely to be affected by background noise around the impact inspection device.

[0010] Alternatively, the measuring means includes a roller for traveling along the surface of the inspection object, an arm for pressing the roller against the surface of the inspection object at a predetermined pressure, and is attached to the arm. And an accelerometer. With this configuration, the vibration of the inspection object can be measured by the accelerometer. Also, the measuring means is:
It may be a laser displacement meter or a laser vibrometer. Further, the characteristic extracting means may be configured to extract the characteristic value based on the vibration waveform after a predetermined time has elapsed from the impact of the inspection target. With this configuration, the determination can be performed with high accuracy.

The characteristic extracting means performs a Fourier transform on the vibration waveform measured by the measuring means, removes a frequency spectrum corresponding to a noise component from the frequency spectrum obtained by the Fourier transform, and removes the noise component. A noise component may be removed from the vibration waveform by performing an inverse Fourier transform on the frequency spectrum. With this configuration, noise due to the configuration of the impact inspection device can be removed.

Further, the present invention provides a striking means for striking an object to be inspected, a measuring means for measuring a sound wave excited by the striking, and a predetermined vibration from a vibration waveform measured by the measuring means. A characteristic extracting means for extracting characteristic values of the waveform, a comparing means for comparing the characteristic value extracted by the characteristic extracting means with a predetermined threshold value, and an inspection based on a comparison result by the comparing means. A hit inspection device having a judgment means for making a judgment on an object, wherein the measuring means is a directional microphone arranged to detect a sound near the hit point by the hitting means. With this configuration, even in a wide range of inspections, a uniform impact inspection can be performed, and it is hardly affected by ambient noise such as background noise.

[0013]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the impact inspection device 1 according to the first embodiment includes a bogie 2 for traveling on the surface of the inspection target T, and a bogie 4 of the bogie 2.
A tire 4 attached to a corner and rolling on the surface of the inspection target T; a hitting unit 6 attached to the carriage 2 for hitting the inspection target T; and a measuring unit for measuring a sound generated by the hitting. It has a directional microphone 8 and a data processing device 10 for processing data measured by the directional microphone 8.

The striking means 6 has a striking ball 12 for striking the test object T, and an actuator 14 having a spring or the like for driving the striking ball 12. The directional microphone 8 has a sound collecting plate 16 for collecting sound near the hit point of the inspection target T, and a microphone 18 for collecting sound reflected by the sound collecting plate 16. . The microphone 18 is arranged at a focal position of the sound collecting plate 16 so that sound waves reflected by the sound collecting plate 16 can be collected. The data processing device 10 includes the microphone 1
A characteristic extracting means 20 connected to a microphone 18 for processing the signal detected by the signal extracting means 8 for extracting characteristic values of the detected signal;
A comparison unit 22 for comparing the characteristic value extracted by the comparison with a predetermined threshold value, and a determination unit 24 for determining the presence or absence of a defect of the inspection target T based on the comparison result by the comparison unit 22.

Next, the operation of the impact inspection device 1 according to the first embodiment will be described with reference to FIGS. FIG. 2 is a diagram illustrating a use state in a case where the impact inspection device 1 according to the first embodiment of the present invention is used for inspection of a defect on an inner wall of a tunnel. FIG.
As shown in (1), when inspecting a high place on a wall surface, a lifter L capable of supporting the impact inspection device 1 at an arbitrary height and an arbitrary angle is loaded on an inspection vehicle C such as a truck. . The height and angle of the lifter L are adjusted so that the tires 4 at the four corners of the truck 2 of the impact inspection device 1 come into contact with the wall surface T to be inspected. Next, while the inspection vehicle C is running at a predetermined speed, the wall means T is continuously hit by the hitting means 6, and the sound generated by the hit is detected by the directional microphone 8. By repeating this operation, the impact inspection of the entire inner wall of the tunnel is performed. In this embodiment, 1
The impact inspection apparatus 1 is run at a speed of about 50 to 60 cm per second, and impacts are performed at a time interval of about 5 times per second. The traveling speed and the impact interval of the impact inspection device 1 can be arbitrarily changed according to the application. Further, depending on the application, for example, when performing a floor impact inspection, the inspection vehicle C and / or the lifter L may not be used. In addition, depending on the application, the inspection vehicle C
May be stopped to acquire data.

Next, data processing performed by the data processing device 10 will be described with reference to FIGS. First, before performing the impact inspection, an impact test is performed on a sound-free portion of the wall surface T, which is the inspection object, to obtain determination reference data for determining the presence or absence of a defect. FIG. 3 is a flowchart illustrating a procedure for acquiring the determination reference data. First, a healthy portion of the wall surface T to be inspected is selected by a conventional impact inspection method. Next, the impact inspection device 1 is set in a healthy part as shown in FIG. 2, and the inspection vehicle C is run at a predetermined speed. In step S1, the striking means 6 is operated to strike the wall surface T continuously with the striking ball 12. In step S2, sound near the hit point generated by the hit is detected by the directional microphone 8 and recorded. Generally, a single blow of an inspection object generates a sound wave having a damped vibration wave shape as shown in FIG. In the present embodiment, the time interval of the impact by the impact ball 12 is set such that the next impact is performed after the attenuation vibration waveform by one impact converges to zero. If you have recorded N times of damped vibration waveform data,
Proceed to step S3. The number N can be arbitrarily determined according to the application. In the present embodiment, the number of times N is 5 to 1
Although it is set to 0 times, this number can be set arbitrarily according to the application.

Next, in step S3, the characteristic extracting means 20 of the data processing device 10
From damped oscillation waveform data by each time striking, extracting a signal waveform of the interval time t ₂ from time t ₁ of the detected signal waveform. This is because the initial part of the detected time history data includes many characteristics of the surface of the impact point of the inspection target T, and the latter part of the time history data includes many defects. In the present embodiment, the times t ₁ and t ₂ are both set to 10
msec. The times t ₁ and t ₂ can be arbitrarily determined according to the application, and the time t ₁ may be set to 0. In step S4, characteristics extraction unit 20 calculates the effective level (RMS value) _{x 0} each time the striking by the signal waveform taken at the step S3. Moreover, the characteristic extraction unit 20, a frequency spectrum calculated each time of the time history signal waveform by Fourier transform, the frequency spectrum seek dominant frequency f ₀ is a frequency at which a peak value.

In step S5, the characteristic extracting means 20
N effective levels x calculated in step S4₀Calculation
Operative mean x_0AVAnd the dominant frequency f₀Arithmetic mean of
f_{0 AV}Is calculated. Furthermore, the effective level x₀Standard deviation of
x_0RAnd the dominant frequency f ₀Standard deviation f_0RCalculate
I do. In step S6, the calculated x_0AV,
f_0AV, X_0R, F_0RThe judgment criteria data of the healthy part
And the process ends.

Depending on the application, the reference data may be obtained by hitting the same location N times without running the inspection vehicle C. Furthermore, the acquisition of the reference data may be performed at any number of locations on the wall surface where it is known that there is no defect. In the present embodiment, the judgment reference data is obtained by hitting a part of the healthy wall surface of the tunnel to be subjected to the impact inspection. However, depending on the application, an object different from the inspection object T for which the impact inspection is performed may be obtained. It is also possible to obtain judgment reference data by hitting an object, and perform a hit inspection of the inspection target T using the data.

Next, referring to FIG. 5, the procedure of the impact inspection will be described. First, as shown in FIG. 2, the impact inspection device 1 is set on a wall surface T where a defect is to be found by an impact inspection, and the inspection vehicle C is run. Next, in steps S11 to S14, the wall T is hit, and the latter half of the detected time history data is taken out.
Is calculated. These procedures are the same as the procedures of steps S1 to S4 in FIG. In the present embodiment, the number of times n is set to 5 to 10, but the predetermined number of times n can be set to an arbitrary number according to the application. Further, the traveling speed of the inspection vehicle C and the time interval of each impact can also be arbitrarily set.

In step S15, the reference data x of the effective level x and the average value of the effective level acquired by the n-time impact
From _0AV, the effective level variation amount _{x R} (Equation 1)
Calculate by _{x R = {(1 / n} ) Σ (x-x 0AV) 2} (1/2) ( Equation 1) Similarly, calculate the variation amount _{f R} of the dominant frequency f by (Equation 2). In _{f R = {(1 / n} ) Σ (f-f 0AV) 2} (1/2) ( Equation 2) Step S16, at the determined effective levels variation amount _{x R} and the effective level of the standard deviation step S15 the ratio α of the reference data x _0R, and the ratio β of the reference data f _0R of the standard deviation of the variation amount f _R and dominant frequency of the dominant frequency, the (equation 3) is calculated by (equation 4). α = x _R / x _0R (Formula 3) β = f _R / f _0R (Formula 4)

In step S17, the data processing device 10
The comparing means 22 compares the values of α and β obtained in step S16 with predetermined reference values α ₀ and β ₀ . In the present embodiment, the values of α ₀ and β ₀ are 2.
The values of the reference values α ₀ and β ₀ can be set to arbitrary values according to the application. Further, the determination means 24 of the data processing device 10 determines that the values of α and β are both predetermined reference values α ₀ and β ₀
If smaller, it is determined that there is no defect, and a display to that effect is displayed. alpha, the reference value alpha ₀ at least one of a predetermined value of _beta, when beta is smaller than _0, it is determined that there is a defect in the range obtained the n data of the inspection object T, display its effect Is done. When the impact inspection device 1 is moved and one location is hit to obtain n data, it is determined that there is a defect near the point where the impact was performed. When n pieces of data are acquired in a predetermined range of the inspection object T and the presence or absence of a defect is determined, the procedure from step S11 is repeated to inspect another portion.

In the present embodiment, the inspection vehicle C is run.
While hitting continuously, obtain a predetermined number of data
However, depending on the application, for each impact
The vehicle C may be stopped, and a plurality of times may be performed at the same location.
You may hit. Also, in the present embodiment, n data
After acquiring data, data processing such as calculation of variation
But data acquisition and data processing are performed in parallel.
You may do it. Further, in the present embodiment, the impact
Effective level to evaluate the amplitude of the obtained data
, But instead of the effective level, the power spectrum
Or the maximum amplitude may be used. In this embodiment,
Uses the standard deviation to assess data variability
However, instead of standard deviation, statistics such as mean deviation and variance
An amount may be used. Further, in the present embodiment, α, β
Value, both are predetermined reference values α₀, Β ₀If less than
It is determined that there is no defect, but even if another determination method is adopted
Good, and not only the presence / absence of defects but also the type of defects
It can also be configured to be able to do so.

According to the first embodiment of the present invention, the object to be inspected is continuously hit by the hitting means without using the inspector of the hitting inspection, so that a uniform hitting inspection can be quickly performed over a wide range. Can be. Further, the impact inspection according to the present embodiment uses a directional microphone as a measuring means and collects the sound near the impact point of the inspection object, so that it is less affected by background noise. Further, in the present embodiment, since the signal waveform after a lapse of a predetermined time from the impact is used for the defect determination, the characteristics of the defective portion can be detected with high accuracy.

Next, with reference to FIGS. 6 and 7, a description will be given of an impact inspection device 30 according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and the description of the same components, operations, and effects as those in the first embodiment will be omitted. As shown in FIG. 6, the impact inspection device 30 of the second embodiment differs from the first embodiment in that an arm to which an accelerometer is attached is used as measurement means 32 for measuring vibration. The measuring means 32 includes a roller 34 for rolling on the surface of the inspection object T,
, A pressing spring 38 mounted on the base end of the arm 36 for pressing the roller 34 against the test object T, an accelerometer 40 for measuring the vibration of the test object T, And Further, a data processing device 42 for processing data measured by the measuring means 32 is connected to the accelerometer 40.

Next, the operation of the second embodiment will be described with reference to FIG. First, similarly to the first embodiment, the inspection object T is hit by the hitting means 6 while the inspection vehicle C is running. The vibration excited on the inspection object T by the impact is applied to the accelerometer 40 via the roller 34 and the arm 36.
Is measured by The time history acceleration waveform data measured by the accelerometer 40 is processed by the data processing device 42. The data processing performed in the data processing device 42 is the same as that of the first embodiment except for the second half data extraction processing performed in step S3 in FIG. 3 and step S13 in FIG. Below, the second
A process of extracting the latter half data in the embodiment will be described.

When the test object T is hit, the accelerometer 40
As a result, a time history acceleration waveform as shown in FIG. 7A is detected. However, this waveform includes a vibration component corresponding to the natural frequency formed by the elasticity of the roller 34 and the mass of the roller 34 and the arm 36 and the like, the elasticity of the pressing spring 38, and the elasticity of the roller 34 and the arm 36 and the like. A vibration component corresponding to the natural frequency formed by the mass is included. Therefore, the time history acceleration waveform shown in FIG. 7A is Fourier-transformed to obtain a frequency spectrum waveform shown in FIG. 7B, and the above-mentioned frequency spectrum of the natural frequency is removed from this frequency spectrum (FIG. 7). (C)). In this way, by inverse Fourier transforming the frequency spectrum waveform from which unnecessary frequency components have been removed,
As shown in FIG. 7D, a time history acceleration waveform from which noise due to the influence of the roller 34, the arm 36 and the like has been removed is obtained. By extracting the latter half of the time history acceleration waveform from which noise is removed shown in FIG. 7D, a necessary time history acceleration waveform can be obtained (see FIG. 7E). The above-described noise removal processing may be omitted depending on the application.

The impact inspection device 30 according to the second embodiment of the present invention
According to, because the vibration of the surface of the inspection object is directly measured,
Defect detection can be performed with high accuracy even when the background noise is large. Further, by removing unnecessary frequency components from the time history acceleration waveform measured by the accelerometer, a defect can be detected with higher accuracy.

Next, with reference to FIG. 8, an impact inspection device 50 according to a third embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals.
A description of the same configuration, operation, and effects as those of the first embodiment or the second embodiment will be omitted. As shown in FIG. 8, the impact inspection device 50 according to the third embodiment differs from the first embodiment in that a laser displacement meter 52 is used as a measurement unit for measuring vibration. A data processing device 54 for processing the measured data includes a laser displacement meter 5.
2 are connected.

Next, the operation of the third embodiment will be described with reference to FIG. First, similarly to the first embodiment, the inspection object T is hit by the hitting means 6 while the inspection vehicle C is running. The vibration excited on the inspection object T by the impact is measured by the laser displacement meter 52. The time history displacement waveform data measured by the laser displacement meter 52 is processed by the data processing device 54. In the second embodiment, the roller 34 and the pressing spring 38 are obtained from the time history acceleration waveform data measured by the accelerometer 40.
Although the vibration component due to the influence of is removed, in the present embodiment,
Data processing for removing a vibration component or the like corresponding to the natural frequency formed by the elasticity of the tire 4 and the mass of the bogie 2 and the like is performed. The data processing according to the present embodiment is the same as the data processing according to the second embodiment except that the frequency band to be removed as noise is different, and a description thereof will be omitted.

According to the third embodiment of the present invention, the vibration of the object to be inspected can be directly measured in a non-contact manner by the laser displacement meter, and the handling of the apparatus becomes easy because of the non-contact type. As a modification, a vibration speed or vibration acceleration of the inspection object T may be measured by using a laser vibrometer instead of the laser displacement meter 52.

While the preferred embodiments of the present invention have been described above, 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 changed. In particular, although the impact inspection device according to the above-described embodiment of the present invention is a device for detecting a defect of an inspection object, an object to be discovered by the impact inspection device is not limited to a defect. Further, depending on the application, the tire provided on the cart and / or the cart may be omitted. Furthermore, in the present embodiment, the ratio of the reference data x _0R run level variation amount x _R and execution level alpha, and, based on the ratio between the reference data f _0R variation amount f _R and dominant frequency of the dominant frequency β Although the determination is made based on the data, it is also possible to adopt a configuration in which the determination is made based on the data of one impact instead of the variation of the data.

[0033]

According to the impact inspection apparatus of the present invention, a uniform impact inspection can be performed even in a wide range of inspections.
In addition, the impact inspection device of the present invention can perform an impact inspection that is not easily affected by ambient noise such as background noise.

[Brief description of the drawings]

FIG. 1 is a side view of an impact inspection device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a use state of the impact inspection device according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a procedure for acquiring reference data in the first embodiment of the present invention.

FIG. 4 is a graph showing a waveform measured by a directional microphone in the first embodiment of the present invention.

FIG. 5 is a flowchart showing a procedure for performing a hit test in the first embodiment of the present invention.

FIG. 6 is a side view of an impact inspection device according to a second embodiment of the present invention.

FIG. 7 is a graph showing data processing in a second embodiment of the present invention.

FIG. 8 is a side view of a hit inspection device according to a third embodiment of the present invention.

[Explanation of symbols]

 C Inspection vehicle L Lifter T Object to be inspected 1 Impact inspection device according to the first embodiment 2 Bogie 4 Tire 6 Impact device 8 Directional microphone 10 Data processing device 12 Impact ball 14 Actuator 16 Sound collector 18 Microphone 20 Characteristic extraction device 22 Comparison means 24 Judgment means 30 Impact inspection device according to the second embodiment 32 Measuring means 34 Roller 36 Arm 38 Pressing spring 40 Accelerometer 50 Impact inspection device according to the third embodiment 52 Laser displacement meter

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigemitsu Kikuchi 12 Nishiki-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. F-term in Yokohama Works (reference) 2G047 AA10 BC03 BC04 CA03 GA05 GA18 GD00 GG12 GG33 GJ02 2G064 AA05 AA11 AB01 AB02 AB11 AB13 AB24 BA02 BC32 BD02 CC43 CC45 CC58

Claims (8)

[Claims] 1. A striking means for striking an inspection object, a measuring means for measuring a sound wave or a vibration excited by the striking, and a predetermined vibration waveform from a vibration waveform measured by the measuring means. A characteristic extracting means for extracting characteristic values; a comparing means for comparing the characteristic values extracted by the characteristic extracting means with a predetermined threshold; and an inspection object based on a comparison result by the comparing means. And a determining means for determining the impact on the test object, comprising: a bogie loaded with the hitting means and the measuring means for running along the surface of the inspection object. Inspection equipment. 2. The method according to claim 1, wherein the characteristic value of the vibration waveform is an amplitude of a time history vibration waveform, an amplitude of a frequency spectrum of the vibration waveform, or
The impact inspection apparatus according to claim 1, wherein the impact inspection apparatus is calculated based on a dominant frequency of a frequency spectrum of the vibration waveform. 3. The directional microphone according to claim 1, wherein the measuring means is a directional microphone arranged to detect a sound near a hit point by the hitting means.
The impact inspection device according to 1. 4. The measuring means comprises: a roller for traveling along the surface of the test object; an arm for pressing the roller against the surface of the test object at a predetermined pressure; and an arm attached to the arm. The impact inspection device according to claim 1, comprising: an accelerometer; 5. The method according to claim 1, wherein the measuring means is a laser displacement meter or
The impact inspection device according to claim 1 or 2, wherein the impact inspection device is a laser vibrometer. 6. The characteristic extracting unit according to claim 1, wherein the characteristic extracting unit extracts the characteristic value based on a vibration waveform after a predetermined time has elapsed from the impact of the inspection target. The impact inspection device according to 1. 7. The characteristic extracting means performs a Fourier transform on the vibration waveform measured by the measuring means, and removes a frequency spectrum corresponding to a noise component from a frequency spectrum obtained by the Fourier transform. The impact inspection apparatus according to any one of claims 1 to 6, wherein a noise component is removed from the vibration waveform by performing a Fourier inverse transform on the removed frequency spectrum. 8. A striking means for striking an inspection object, a measuring means for measuring a sound wave excited by striking, and a characteristic value of a predetermined vibration waveform from a vibration waveform measured by the measuring means. A characteristic extracting means for extracting the characteristic value; a comparing means for comparing the characteristic value extracted by the characteristic extracting means with a predetermined threshold value; and a judgment on the inspection object based on a comparison result by the comparing means. And a determination means for performing the following. The impact inspection apparatus, wherein the measurement means is a directional microphone arranged to detect a sound near the impact point by the impact means. .