JP2010175519A - Ultrasonic inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire an accurate ultrasonic inspection result by removing a noise caused by multi-echoes generated inside a rotator of an ultrasonic probe from a received ultrasonic signal, and to attain efficient continuous measurements. <P>SOLUTION: This ultrasonic inspection device includes the ultrasonic probe 10 for allowing an ultrasonic wave to enter a measuring object, and receiving the ultrasonic wave from the measuring object; and a signal processing part 24 for processing an ultrasonic signal received by the ultrasonic probe 10. The ultrasonic probe 10 includes an ultrasonic vibrator, and the rotator arranged rotatably between the ultrasonic vibrator and the measuring object, and having a circular cross section passed by the ultrasonic wave. The signal processing part 24 includes a filter for removing at least either of frequency components higher than the upper limit frequency set beforehand and a lower frequency component than the lower-limit frequency, set beforehand from the ultrasonic signal received by the ultrasonic probe. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic inspection apparatus that can be preferably used for, for example, an ultrasonic flaw detection test and a plate thickness measurement.

  Conventionally, in various fields, in order to measure the thickness of metal parts or the like, or to examine the occurrence or size of cracks on the surface or inside, inspection using ultrasonic waves has been performed (for example, (See Patent Literature 1, Non-Patent Literature 1, Non-Patent Literature 2, and Non-Patent Literature 3). The measurement of the thickness by the ultrasonic wave can be performed by making the ultrasonic wave incident on the measurement object and receiving the ultrasonic wave reflected by the bottom surface of the measurement object.

  Moreover, the measurement of the crack depth by an ultrasonic wave can be performed as follows. First, the transmitting probe and the receiving probe are arranged on the surface of the measurement object with a predetermined distance therebetween. Next, an ultrasonic wave enters the measurement object from the transmission probe. Of the incident ultrasonic waves, the ultrasonic waves that are diffracted at the bottom of the crack in the measurement object and go to the opposite side of the transmitting probe are received by the receiving probe and received from the transmission of the ultrasonic waves. Time until is measured. The distance traveled by the ultrasonic wave is calculated from this measurement time. Thereafter, the crack depth is calculated from the calculated distance and the distance from the transmitting probe to the receiving probe.

Further, Patent Document 2 discloses an ultrasonic flaw detector in which a transmission probe and a reception probe are respectively built in a pair of wheels. Patent Document 3 discloses an ultrasonic probe including a sphere rotatably held between an ultrasonic transducer and a measurement object. According to such an ultrasonic flaw detection apparatus, the transmitting probe and the receiving probe, or the position of the ultrasonic probe can be moved without being separated from the object to be measured. Can be measured.
JP 54-150188 A JP 2005-315800 A JP 2008-51557 A "BRITISH STANDARD", 1993, BS 7706 Joseph Krautkramer, by Herbert Krautkramer, "Ultrasonic Testing of Materials", Springer Verlag, 1990, p. . 323 "Ultrasonic flaw detection test III", Japan Nondestructive Inspection Association, February 1, 1989, p133-134

  However, when the ultrasonic wave passes through a rotating body having a circular cross section such as a wheel or a sphere as in the above-described prior art, multiple echoes of ultrasonic waves are likely to be generated inside the rotating body. This multiple echo becomes noise that lowers the accuracy of the ultrasonic inspection result.

  Therefore, according to the present invention, noise due to multiple echoes generated inside the rotating body of the ultrasonic probe is removed from the received ultrasonic signal, and an accurate ultrasonic inspection result can be obtained, and efficient continuous measurement is possible. An object is to provide an ultrasonic inspection apparatus.

  The ultrasonic inspection apparatus disclosed in the present specification includes an ultrasonic probe that makes an ultrasonic wave incident on a measurement object and receives ultrasonic waves from the measurement object, and the ultrasonic probe receives the ultrasonic probe. A signal processing unit for processing an ultrasonic signal, and the ultrasonic probe is disposed between an ultrasonic transducer and the ultrasonic transducer and the measurement object so as to be rotatable. The signal processing unit has a frequency component higher than a preset upper limit frequency and a preset lower limit from the ultrasonic signal received by the ultrasonic probe. A filter that removes at least one of frequency components lower than the frequency;

  The rotating probe placed between the ultrasonic probe and the measurement object keeps the ultrasonic probe in close contact with the measurement object and allows the ultrasonic probe to enter the ultrasonic wave on the surface of the measurement object. Can be moved. Therefore, the measurement can be performed efficiently and continuously without separating the ultrasonic probe from the measurement object. Furthermore, the filter of the signal processing unit removes at least one of a frequency component higher than the upper limit frequency and a frequency component lower than the lower limit frequency from the ultrasonic wave received by the ultrasonic probe. Therefore, noise due to multiple echoes generated inside the rotating body of the ultrasonic probe can be removed from the received ultrasonic signal. As a result, efficient continuous measurement is possible, and an accurate inspection result can be obtained.

  According to the ultrasonic inspection apparatus disclosed in the specification of the present application, an accurate ultrasonic inspection result can be obtained by removing noise caused by multiple echoes generated inside the rotating body of the ultrasonic probe from the received ultrasonic signal, and Efficient continuous measurement is possible but possible.

  In an embodiment of the present invention, the ultrasonic inspection apparatus is configured to receive at least one of the upper limit frequency and the lower limit frequency from a user and record the input as the upper limit frequency and the lower limit frequency of the filter of the signal processing unit. A part may be further provided.

(First embodiment)
[Configuration of ultrasonic inspection equipment]
FIG. 1 is a functional block diagram showing an example of the configuration of the ultrasonic inspection apparatus according to the present embodiment. The ultrasonic inspection apparatus shown in FIG. 1 includes an ultrasonic probe 10 and a computer 2. The ultrasonic probe 10 and the computer 2 are connected by a wiring cable 14. An input device 51 and a display device 52 are connected to the computer 2.

  The ultrasonic probe 10 comes into contact with the measurement object, enters the ultrasonic wave, and receives the ultrasonic wave reflected from the measurement object. The detailed configuration of the ultrasonic probe 10 will be described later. The number of ultrasonic probes 10 connected to the computer 2 is not limited to one, and a configuration in which a plurality of ultrasonic probes 10 are connected to the computer 2 may be used.

  The computer 2 controls the ultrasonic probe 10 in accordance with an instruction from the user via the input device. Further, the computer 2 executes signal processing and analysis processing of the ultrasonic waves received by the ultrasonic probe 10, and outputs the results to the display device. The computer 2 may be configured by a general-purpose computer such as a personal computer including a CPU and a memory, or may be configured by an integrated circuit dedicated to the ultrasonic inspection apparatus. In the present embodiment, the ultrasonic probe 10 and the computer 2 are formed in separate casings and connected by the wiring cable 14. However, the ultrasonic probe 10 and the computer 2 are in one casing. May be formed.

  The input device 51 includes, for example, a mouse, a keyboard, a tablet, or a button. The display device 52 includes, for example, a liquid crystal panel, SED, organic EL, and the like.

  The computer 2 includes a signal processing unit 24, a recording unit 25, a control unit 26, a setting unit 27, a calculation unit 28, and a user interface unit (UI unit) 29. The functional units of the signal processing unit 24, the control unit 26, the setting unit 27, the calculation unit 28, and the user interface unit (UI unit) 29 can be realized by a processor included in the computer 2 executing a predetermined program. . The recording unit 25 can be realized by, for example, an internal recording device such as a memory or a hard disk built in the computer 2 or an external recording device accessible by the computer 2. Note that a program that causes the computer 2 to execute the processing of each functional unit described above and a recording medium that records such a program are also included in the embodiments of the present invention.

[Description of each functional unit of the computer 2]
The UI unit 29 is an interface that enables information exchange between the user and the computer 2. For example, the UI unit 29 receives an input from the user via the input device 51 and passes the input to the control unit 26 or the setting unit 27. The UI unit 29 receives the calculation result of the calculation unit 28 and displays it on the display device 52.

  The control unit 26 controls the operation of the ultrasound probe 10 according to the input from the user. For example, the control unit 26 can control the timing of ultrasonic incidence by sending a signal instructing the ultrasonic probe 10 to transmit and stop the ultrasonic wave. In this embodiment, the case where the user directly operates the ultrasonic probe 10 to determine the measurement position will be described. However, the position of the ultrasonic probe 10, the angle at which the ultrasonic wave is incident on the measurement object, and the like are described. The control unit 26 may automatically control.

  The signal processing unit 24 receives the ultrasonic signal received by the ultrasonic probe 10, processes it into a state suitable for analysis, and records it in the recording unit 25. In the present embodiment, the signal processing unit 24 removes at least one of a frequency component higher than a preset upper limit frequency and a frequency component lower than a preset lower limit frequency from the ultrasonic signal. That is, the signal processing unit 24 functions as a band-pass filter that passes only signals in a band between the upper limit frequency and the lower limit frequency. The values of the upper limit frequency and the lower limit frequency can be recorded in the recording unit 25 in advance.

  The setting unit 27 accepts input of the values of the upper limit frequency and the lower limit frequency from the user via the input device 51 and the UI unit 29 and records them in the recording unit 25. The signal processing unit 24 can operate as a filter that passes a signal in a band between the upper limit frequency and the lower limit frequency recorded in the recording unit 25.

  Here, the upper limit frequency and the lower limit frequency are preferably set so that noise included in the ultrasonic signal is removed. In particular, as will be described later, it is preferable to set an upper limit frequency and a lower limit frequency so that multiple echoes generated in the sphere included in the ultrasound probe 10 can be efficiently removed.

  For example, when performing an inspection using an ultrasonic inspection apparatus, the user can calibrate the ultrasonic inspection apparatus using a test piece made of the same material as the object to be inspected in advance. In the case of the ultrasonic inspection apparatus of the present embodiment, the user can determine the upper limit frequency and the lower limit frequency during calibration using the test piece. For example, the setting unit 27 transmits the ultrasonic signal waveform received by the ultrasonic probe 10 from the test piece and the ultrasonic signal waveform passed through the signal processing unit 24 through the UI unit 29 during calibration. You may display on the display apparatus 52. FIG. The user can adjust the values of the upper limit frequency and the lower limit frequency of the filter of the signal processing unit 24 so as to minimize noise while viewing these signal waveforms.

  That is, the setting unit 27 causes the display device 52 to display the ultrasonic signal waveform received by the ultrasonic probe 10 and the ultrasonic signal waveform processed by the signal processing unit 24, and from the user, A function of accepting input of values of the upper limit frequency and the lower limit frequency of the processing unit 24 can be provided. Thereby, the user can set the value of the limiting frequency of the filter while observing the signal waveform at the time of calibration, for example. At the time of calibration, parameters for measurement such as the material, size, and sensitivity of a sphere (described later) in the ultrasonic probe 10 may be set.

  In the present embodiment, the case where the signal processing unit 24 functions as a bandpass filter whose pass band is a band between the upper limit frequency and the lower limit frequency has been described. However, the function of the signal processing unit 24 is limited to this. Absent. For example, it may function as a low-pass filter that cuts a signal in a band higher than the upper limit frequency, or may function as a high-pass filter that cuts a signal in a band lower than the lower limit frequency. The signal processing unit 24 may perform signal processing other than the filter function.

  The calculation unit 28 calculates a value indicating the structure of the measurement object based on the signal processed by the signal processing unit 24 and recorded in the recording unit 25. The calculated value can be displayed on the display device 52 through the UI unit 29. For example, the calculation unit 28 calculates a time from when the ultrasonic wave is incident on the measurement object from the ultrasonic probe 10 until it is received by the ultrasonic probe 10, and the ultrasonic wave advances from this time. The distance can be calculated. Thereby, for example, the plate thickness of the measurement object, the depth of the crack, and the like can be obtained.

[Configuration of Ultrasonic Probe 10]
FIG. 2 is a cross-sectional view showing an example of a schematic configuration of the ultrasonic probe 10, FIG. 3 is an external perspective view thereof, and FIG. 4 is an exploded perspective view thereof.

  The ultrasonic probe 10 includes an ultrasonic transducer 11 that emits ultrasonic waves and / or receives ultrasonic waves, and a sphere 12 disposed between the ultrasonic transducer 11 and the measurement object 100. . The spherical body 12 is an example of a rotating body.

  The ultrasonic transducer 11 is fixed to the lower end of the transducer holder 13 including a sound absorbing material. An electrical signal is transferred to the ultrasonic transducer 11 through the wiring cable 14 led out from the transducer holder 13. The vibrator holder 13 is inserted into a through hole 21 a formed substantially along the central axis of the substantially cylindrical first support member 21, and is fixed to the first support member 21 using a fixing screw 15.

  From the opening on one side of the hollow cylindrical second support member 22, the sphere 12 and the plurality of support balls 16 are sequentially inserted, and the first support member 21 is further inserted. On the inner wall surface near the opening on the other side of the second support member 22, a seal 23 protrudes in an annular shape. The seal 23 prevents the spherical body 12 from dropping out from the opening on the other side. The sphere 12 is held by the plurality of support balls 16 and the seal 23 so as to be freely rotatable in an arbitrary direction within a cup-shaped space formed by the first support member 21 and the second support member 22.

  As shown in FIG. 2, the ultrasonic transducer 11 and the sphere 12 are arranged close to each other and facing each other. A liquid medium 17 is filled in a cup-shaped space in which the sphere 12 is accommodated, including a gap between the ultrasonic transducer 11 and the sphere 12. The liquid medium 17 is injected through an injection pipe 18 inserted into a through hole formed in the side wall of the second support member 22. The seal 23 prevents the liquid medium 17 from leaking out.

  The material of the sphere 12 is not particularly limited, but is preferably a rubber material. As the rubber material, for example, silicon rubber, NBR rubber, urethane rubber, viton rubber, or the like can be used. By using a rubber-based material, when the sphere 12 is pressed against the surface of the measurement object 100 during measurement, the sphere 12 is deformed and a contact region 110 having an area in close contact with the surface of the measurement object 100 is formed. The This facilitates the propagation of ultrasonic waves between the measurement object 100 and the sphere 12 via the contact region 110, and between the ultrasonic probe and the measurement object, which is normally required in ultrasonic flaw detection. The contact medium applied to is not necessary.

  The ultrasonic wave emitted from the ultrasonic transducer 11 is preferably focused in a beam shape in or near the contact region 110 between the sphere 12 and the surface of the measurement object 100. Thereby, a stronger ultrasonic wave can be made incident into the measurement object 100. In addition, it is possible to suppress noise that is generated when the ultrasonic wave does not enter the measurement object 100 and is reflected by the surface of the sphere 12.

A method for focusing the ultrasonic wave is not particularly limited. For example, as shown in FIG. 2, a composite vibrator may be used as the ultrasonic vibrator 11, and the composite vibrator may be deformed so that the surface facing the sphere 12 is a concave curved surface. The composite vibrator is a composite vibrator in which a large number of minute piezoelectric ceramics are embedded in lattice points in a sheet-like material such as a polymer. The composite vibrator has flexibility and can be easily formed into an arbitrary three-dimensional curved surface. In particular, the 1-3 composite vibrator is preferable because it has high energy conversion efficiency and high sensitivity. By deforming the composite vibrator so that the surface of the composite vibrator facing the sphere 12 is a concave curved surface, the incident angle of the ultrasonic wave with respect to the sphere 12 is reduced.
It is also possible to reduce the number of ultrasonic waves that are reflected by the surface and do not enter the sphere 12.

  The curvature radius of the surface of the composite vibrator facing the sphere 12 is preferably slightly larger than the curvature radius of the outer surface of the sphere 12. Thereby, the focal position of the focused ultrasonic beam can be made to substantially coincide with the contact region 110 between the sphere 12 and the surface of the measurement object 100. In addition, the method for focusing an ultrasonic wave is not limited to the above.

  The liquid medium 17 facilitates the propagation of ultrasonic waves between the ultrasonic transducer 11 and the sphere 12. The material of the liquid medium 17 is not particularly limited, but for example, grease, glycerin, or the like can be used. The material of the liquid medium 17 is set so that the propagation speed of the ultrasonic wave propagating in the liquid medium 17 is the same as the propagation speed of the ultrasonic wave propagating in the sphere 12 and / or the propagation speed of the ultrasonic wave propagating in the support member. If selected, noise caused by reflection of ultrasonic waves at each part of the ultrasonic probe 10 can be reduced.

  The support ball 16 is a sphere having a smaller diameter than the sphere 12. The material of the support balls 16 is not particularly limited, but for example, stainless steel can be used. The number of support balls 16 is not particularly limited. Note that the sphere 12 may be supported by a method other than the plurality of support balls 16 as long as the sphere 12 can be freely rotated.

[Example of thickness measurement method]
Next, an example of a method for measuring the thickness of the measurement object 100 using the ultrasonic probe 10 will be described. FIG. 5 is a diagram for explaining the arrangement of the ultrasound probe 10 when the thickness of the measurement object 100 is measured. In the example of thickness measurement shown in FIG. 5, one ultrasonic probe 10 is used. First, as shown in FIG. 2, the user moves the ultrasonic probe 10 to the measurement object 100 so that the ultrasonic transducer 11 is substantially located on the normal line to the surface of the measurement object 100 in the contact region 110. Press on. Next, the ultrasonic transducer 11 is vibrated according to an instruction from the control unit 26 of the computer 2. The ultrasonic wave emitted from the ultrasonic vibrator 11 passes through the liquid medium 17 and the sphere 12 in this order, and enters the measurement object 100 through the contact region 110. The incident ultrasonic wave reaches the surface opposite to the incident surface of the measuring object 100, is reflected here, and enters the ultrasonic transducer 11 through the path opposite to the above to vibrate it. The ultrasonic transducer 11 converts this vibration into an electric signal and outputs it to the computer 2. In the computer 2, the thickness of the measurement object 100 can be calculated by measuring the time from the transmission of the electrical signal through the signal processing unit 24 to the reception of the ultrasonic wave by the ultrasonic transducer 11. Can do.

  In order to change the measurement position on the measurement object 100, the ultrasonic probe 10 may be moved in an arbitrary direction while the ultrasonic probe 10 is pressed against the measurement object 100. During movement, the sphere 12 rolls on the measurement object 100 while maintaining a close contact state with the surface of the measurement object 100. Therefore, if the transmission and reception of ultrasonic waves are repeated during movement, the thickness measurement can be performed continuously one after another. For example, the position of the ultrasonic probe 10 on the measurement object 100 and the ultrasonic signal received at the position are recorded in the recording unit 25 in association with each other.

[Example of method for measuring crack depth of measurement object]
Next, an example of a method for measuring the crack depth formed on the measurement object 100 using the ultrasonic probe 10 will be described. In the crack depth measurement, an ultrasonic inspection apparatus including two ultrasonic probes 10 is used. One of the two ultrasonic probes 10 is a transmitting probe (transmitter) that transmits ultrasonic waves, and the other is a receiving probe (receiver) that receives ultrasonic waves. FIG. 6 is a diagram illustrating an arrangement example of the ultrasonic probe 10 when the crack depth is measured. In the example shown in FIG. 6, the transmission probe 10-1 and the reception probe 10-2 are arranged on the surface of the measurement object 100 with a predetermined distance therebetween. At this time, the two ultrasonic probes 10 are arranged so that the crack 101 formed on the surface of the measuring object 100 crosses between the transmitting probe 10-1 and the receiving probe 10-2. Adjust the positions of -1, 10-2.

  The user simultaneously presses the two ultrasonic probes 10-1 and 10-2 against the measurement object 100. At this time, the angles of the ultrasonic probes 10-1 and 10-2 with respect to the measurement object 100 are perpendicular, that is, exceed the normal to the surface of the measurement object 100 in the contact region 110 as shown in FIG. The angle at which the acoustic transducer 11 is positioned may be used. However, as shown in FIG. 7, so that ultrasonic waves are transmitted toward and received from the crack between the two ultrasonic probes 10-1 and 10-2, It is preferable to incline the two ultrasonic probes 10 in opposite directions with respect to the surface of the measurement object 100. The two ultrasonic probes 10 are holders (see FIG. 2) so that the relative positional relationship (interval, inclination angle, etc.) of the two ultrasonic probes 10-1 and 10-2 is kept constant during measurement. (Not shown) are preferably held together.

  FIG. 8 shows the relative positional relationship among the measurement object 100, the sphere 12, and the ultrasonic transducer 11 for one ultrasonic probe 10-1. Unlike FIG. 2, when the ultrasonic probe 10-1 is tilted as shown in FIG. 8, the ultrasonic transducer 11 is arranged at a position shifted from the normal to the surface of the measurement object 100 in the contact region 110. Is done. At this time, if the distances d1 and d2 between the ultrasonic transducer 11 and the sphere 12 shown in FIG. 8 satisfy d1 <d2, the ultrasonic waves emitted from the ultrasonic transducer 11 are focused in the contact region 110. It is preferable because it is easy to be made. When the depth of the crack is relatively deep, attenuation of the ultrasonic wave becomes large. Therefore, the ultrasonic probes 10-1 and 10-2 are inclined as shown in FIG. Focusing the ultrasonic waves emitted from the contact region 110 is effective in accurately measuring the crack depth.

  The user moves the two ultrasonic probes 10-1 and 10-2 while simultaneously pressing the ultrasonic probes 10-1 and 10-2 against the measurement object 100 while emitting ultrasonic waves from the transmitter. If there is no crack between the two ultrasonic probes 10-1 and 10-2, the wave receiver (reception probe 10-2) receives ultrasonic waves that travel straight along the surface of the measurement object 100. If there is a crack between the two ultrasonic probes 10-1 and 10-2, the receiver receives the ultrasonic wave diffracted at the bottom of the crack (see the bottom 101 a in FIG. 6). The deeper the crack, the smaller the energy of the ultrasonic wave received by the receiver, and the computer 2 can measure the depth of the crack from the amplitude of the received ultrasonic wave. Further, if the crack is deep, it takes a long time until the ultrasonic wave is transmitted from the transmitter (transmitting probe 10-1) and then diffracted at the bottom of the crack and received by the receiver. Similarly to the thickness measurement, the computer 2 can also calculate the depth of the crack by measuring the time from transmission to reception of the ultrasonic wave.

  In addition, the ultrasonic wave reflected by the back surface of the measurement object 100 is received by the wave receiver, and the measurement object 100 is measured using the two ultrasonic probes 10 by measuring the time from transmission to reception of the ultrasonic wave. Can also be measured.

[Example of measurement results]
FIG. 9 is a diagram illustrating an example of an output signal from the ultrasonic probe 10 when the plate thickness measurement is performed by the ultrasonic inspection apparatus according to the present embodiment. In the graph shown in FIG. 9, the vertical axis indicates the signal magnitude and the horizontal axis indicates time. FIG. 10 is an example of a screen displayed on the display device 52 when the setting unit 27 receives an input of the lower limit frequency and the upper limit frequency from the user. The screen shown in FIG. 10 includes input areas N1 and N2 for a lower limit frequency (low cutoff frequency) and an upper limit frequency (high cutoff frequency). A line indicating the lower limit frequency L1 and the upper limit frequency H1 input by the user is displayed on the graph indicating the frequency characteristic S1 of the output signal from the ultrasound probe 10.

  FIG. 11 is a graph showing a signal after the output signal shown in FIG. 9 is processed by the filter of the signal processing unit 24. The filter of the signal processing unit 24 removes multiple echoes inside the sphere 12 from the output signal of the ultrasonic probe 10. As a result, a signal with reduced noise as shown in FIG. 11 is obtained and recorded in the recording unit 25. Since the calculation unit 28 calculates the plate thickness of the measurement object based on the signal with reduced noise, more accurate calculation is possible.

  The user sees the received waveform of FIG. 9 (output signal from the ultrasound probe 10), the frequency characteristic S1 shown in FIG. 10, and the signal waveform of FIG. As described above, appropriate values of the lower limit frequency and the upper limit frequency can be determined. The user can input the determined lower limit frequency and upper limit frequency values on the screen shown in FIG. FIG. 12 is a diagram illustrating an example of an output signal from the ultrasonic probe 10-2 when crack depth measurement is performed by the ultrasonic inspection apparatus according to the present embodiment. FIG. 13 is an example of a screen displayed on the display device 52 when the setting unit 27 receives an input of the lower limit frequency and the upper limit frequency from the user. The screen shown in FIG. 13 includes input areas N1 and N2 for the lower limit frequency and the upper limit frequency. In addition, a line indicating the lower limit frequency L2 input by the user is displayed on the graph indicating the frequency characteristic S2 of the output signal from the ultrasonic probe 10-2.

  FIG. 14 is a graph showing a signal after the output signal shown in FIG. 12 is processed by the filter of the signal processing unit 24. The filter of the signal processing unit 24 removes multiple echoes inside the sphere 12 from the output signal of the ultrasonic probe 10-2. As a result, a signal with reduced noise as shown in FIG. 14 is obtained. As a result, more accurate calculation of crack depth is possible.

  For example, the user may output the signal from the ultrasound probe 10-2 shown in FIG. 12, the frequency characteristic S2 shown in FIG. 13, and the signal after being processed by the filter of the signal processing unit 24 shown in FIG. The appropriate lower limit frequency and upper limit frequency can be determined and input on the screen shown in FIG. 13 so that the low frequency noise is removed.

  As described above, according to the present embodiment, the noise of the output signal from the ultrasonic probe is reduced by the filter of the signal processing unit 24, so that the gate measurement can be performed more precisely.

  In addition, although the said embodiment demonstrated plate | board thickness and crack depth measurement, the use of the ultrasonic inspection apparatus concerning this invention is not restricted to these measurements. For example, measurement of material roughness, discrimination of material or material, or estimation of internal defects (lamination, void, etc.) can be performed.

1 is a functional block diagram showing an example of the configuration of an ultrasonic inspection apparatus according to the first embodiment. Sectional drawing which showed an example of schematic structure of the ultrasound probe 10 External perspective view of the ultrasonic probe shown in FIG. 2 is an exploded perspective view of the ultrasonic probe shown in FIG. Diagram for explaining the arrangement of ultrasonic probes when measuring the thickness of the measurement object The figure which shows the example of arrangement | positioning of the ultrasonic probe 10 at the time of measurement of crack depth The figure which shows the structure which inclined the two ultrasonic probes in the mutually opposite direction Indicates the relative positional relationship between the measurement object, sphere, and ultrasonic transducer The figure which shows the example of the output signal from an ultrasonic probe at the time of carrying out thickness measurement The figure which shows the example of a screen displayed on a display apparatus, when a setting part receives the input of the lower limit frequency and upper limit frequency from a user. The graph showing the signal after the output signal shown in FIG. 9 is processed by the filter of the signal processing unit The figure which shows the example of the output signal from an ultrasonic probe at the time of carrying out crack depth measurement The figure which shows the example of a screen displayed on a display apparatus, when a setting part receives the input of the lower limit frequency and upper limit frequency from a user. The graph showing the signal after the output signal shown in FIG. 12 is processed by the filter of the signal processing unit

2 Computer 10 Ultrasonic probe 11 Ultrasonic transducer 12 Sphere 13 Transducer holder 14 Wiring cable 15 Fixing screw 16 Support ball 17 Liquid medium 18 Injection pipe 21 Support member 21a Through hole 22 Support member 23 Seal 24 Signal processor 25 Recording unit 25 Calculation unit 26 Control unit 27 Setting unit 28 Calculation unit 28a Calculation unit 29 UI unit 51 Input device 52 Display device 100 Measurement object

Claims (2)

An ultrasonic probe that makes ultrasonic waves incident on a measurement object and receives ultrasonic waves from the measurement object; and
A signal processing unit for processing the ultrasonic signal received by the ultrasonic probe;
The ultrasonic probe is
An ultrasonic transducer,
A rotating body having a circular cross section through which the ultrasonic wave is disposed, rotatably disposed between the ultrasonic transducer and the measurement object;
The signal processing unit removes at least one of a frequency component higher than a preset upper limit frequency and a frequency component lower than a preset lower limit frequency from the ultrasonic signal received by the ultrasound probe. An ultrasonic inspection apparatus having a filter.   The ultrasonic inspection apparatus further includes a setting unit that receives an input of at least one of the upper limit frequency and the lower limit frequency from a user and records the input as the upper limit frequency and the lower limit frequency of the filter of the signal processing unit.

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