JP3189463B2 - Ultrasonic flaw detector and its probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detector,
In particular, the present invention relates to an ultrasonic flaw detector for detecting a defect of a sample by an ultrasonic beam.

[0002]

2. Description of the Related Art An ultrasonic flaw detector is used for detecting damages and defects inside a metal material or a welded portion. In general, the ultrasonic flaw detector includes a probe having a built-in piezoelectric vibrator for transmitting and receiving an ultrasonic beam on a surface to be detected of a sample, and transmitting and receiving signals for transmitting and receiving signals connected to the probe. It is composed of a search device main body for wave, a monitor for displaying a search result, and the like. This ultrasonic flaw detector transmits ultrasonic waves from the probe to the sample, obtains ultrasonic echo signals reflected from the inside of the sample, and performs arithmetic processing on the signals to search for defects in the sample. is there.

[0003]

Generally, in an ultrasonic flaw detector, a probe from a probe is applied to a probe surface of a sample so that ultrasonic waves can be efficiently transmitted and received between the probe and the sample. The ultrasonic beam needs to be irradiated vertically. As a result, the search accuracy can be increased while maintaining good sensitivity at a constant level.

Therefore, when the surface shape of the search surface of the sample is not flat, the probe is probed in accordance with the surface shape of the sample so that the ultrasonic beam always hits the search surface perpendicularly with the scanning of the probe. It is necessary to teach child angle control data in advance. However, the teaching operation is troublesome and time-consuming, and if the position of the sample changes between teaching and actual measurement, accurate exploration cannot be performed.

An object of the present invention is to enable easy and high-accuracy flaw detection.

[0006]

SUMMARY OF THE INVENTION An ultrasonic flaw detector according to a first aspect of the present invention is for detecting a defect in a sample by an ultrasonic beam. Angle control means. The transmitting and receiving means has a variable transmitting and receiving angle, a main transmitting and receiving unit for transmitting and receiving an ultrasonic beam for searching for a sample, and an ultrasonic wave, which is disposed in close contact with the main transmitting and receiving unit and is uniformly arranged. Means for transmitting and receiving an ultrasonic beam for measuring a beam transmission / reception angle. The transmitting / receiving means is a means for supplying a driving signal for transmitting an ultrasonic beam to the transmitting / receiving means and for processing a reflected signal from the transmitting / receiving means. The display means is means for displaying a processing result of the transmission / reception means. The judging means is means for judging whether or not the angle of the ultrasonic beam transmitted from the transmitting and receiving means is perpendicular to the search surface of the sample based on the processing result of the transmitting and receiving means. The angle control unit is a unit that controls a transmission / reception angle of the ultrasonic beam transmitted from the transmission / reception unit with respect to the sample based on a result of the determination unit.

A probe for an ultrasonic flaw detector according to a second aspect of the present invention is a probe used for an ultrasonic flaw detector for detecting a defect of a sample by an ultrasonic beam. A main transmitting / receiving section for transmitting and receiving a beam, and an ultrasonic beam for measuring the transmitting / receiving angle of the ultrasonic beam while the sample is being explored, which is arranged evenly in close contact with the main transmitting / receiving section. And four sub transmitting / receiving sections.

[0008]

In the ultrasonic flaw detector according to the first aspect of the present invention, the transmitting and receiving means is driven by the driving signal from the transmitting and receiving means during the search of the sample, and the ultrasonic transmitting and receiving means of the transmitting and receiving means transmits the ultrasonic wave to the sample. A sound beam is transmitted. The reflected ultrasonic beam from the sample is received by the main transmitting / receiving section of the transmitting / receiving means and processed by the transmitting / receiving means. The search information as the processing result is displayed on a monitor such as a CRT by the display means.

Here, when the search surface of the sample is not flat, it is necessary to control the angle of transmission and reception of the ultrasonic beam from the wave transmitting and receiving means according to the angle of the search surface. Therefore, first, the angle of the ultrasonic beam with respect to the search surface of the sample is determined by the determination unit based on the processing result of the transmission / reception unit. At this time, if it is determined that the angle is not vertical, the angle control unit controls the transmission and reception angle of the ultrasonic beam with respect to the sample to be vertical. In this angle control operation,
The angle control means controls the transmission / reception angle based on the ultrasonic beams from the four sub-transmission / reception units of the transmission / reception means.

As described above, since the transmission and reception angle of the ultrasonic beam is automatically controlled while the sample is being searched, the angle of the ultrasonic beam can always be determined without any troublesome work such as teaching. , And it is possible to easily perform accurate exploration. In the probe for an ultrasonic flaw detector according to the second invention, an ultrasonic beam is transmitted from the main transmitting / receiving section, and the specimen is searched. During the exploration of the sample,
An ultrasonic beam is transmitted and received from the two sub-transmission / reception units, and a transmission / reception angle of the ultrasonic beam with respect to the sample is measured.

By using such a probe, it is possible to measure the angle of the ultrasonic beam with respect to the search surface of the sample with a simple configuration.

[0012]

1 is a schematic block diagram of an ultrasonic flaw detector according to one embodiment of the present invention. This ultrasonic flaw detector has a flaw detector main body 1 and a scanner 3 including a probe device 2 and a holder 6 thereof. The scanner 3 is attached to an upper part of a water tank 5 in which a sample 4 is stored.

The probe device 2 is held by a probe holder 6. The probe holder 6 includes a cylindrical frame 6a,
An upper frame 6b is attached to the lower end of the cylindrical frame 6a so as to be rotatable in the A-axis direction, and a lower frame 6c is attached to the lower end of the upper frame 6b so as to be rotatable in the B-axis direction. The cylindrical frame 6a is, as shown in FIG.
It has an outer cylinder member 7 and an inner cylinder member 8 penetrating inside the outer cylinder member 7. The probe device 2 is moved in each direction by an X-axis drive mechanism 10, a Y-axis drive mechanism 11, a Z-axis drive mechanism 12, an R-axis drive mechanism 13, an A-axis drive mechanism 14, and a B-axis drive mechanism 15. The transmission and reception angles of the ultrasonic beam can be controlled. Here, the X-axis drive mechanism 10 is a mechanism for moving the probe device 2 in the X-axis direction (see FIG. 2), and the Y-axis drive mechanism 11 is for moving the probe device 2 in the Y direction orthogonal to the X axis. This is a mechanism for moving in the axial direction. Also,
The Z-axis drive mechanism 12 is a mechanism for moving the probe device 2 in the vertical direction, and the R-axis drive mechanism 13 is a mechanism for moving the probe device 2.
Is a mechanism for rotating about the Z axis. Further, the A-axis drive mechanism 14 and the B-axis drive mechanism 15 are mechanisms for rotating the upper frame 6b and the lower frame 6c in the A-axis and B-axis directions, respectively.

In FIG. 2 to FIG.
Are arranged at both ends in the X-axis direction in the upper part of the water tank 5.
A pair of frames 20a and 20b and a pair of frames 20
a pair of guide rods 21a and 21b arranged at both ends of the a and 20b along the X-axis direction, and an X-direction screw shaft 22 arranged close to and parallel to one of the guide rods 21a. , And an X-axis motor 23 for rotating the X-direction screw shaft 22. The pair of guide rods 21a and 21b are respectively provided with retainers 24a and 24a.
b is movably mounted. One retainer 24a
, A nut 25 is fixed, and the nut 25 is screwed to the X-direction screw shaft 22.

The Y-axis drive mechanism 11 includes a pair of retainers 24.
a, 24b along a Y-axis direction, and a Y-direction screw shaft 27 similarly provided between a pair of retainers 24a, 24b in parallel with the guide rod 26.
And a Y-axis motor 28 for rotating the Y-direction screw shaft 27
And A retainer 29 is attached to the guide rod 26 so as to be movable in the Y-axis direction, and a nut portion 29 a screwed to the Y-direction screw shaft 27 is formed in a part of the retainer 29.

The Z-axis drive mechanism 12 includes a Z-axis motor 30 mounted on a retainer 29, a worm 31 and a worm wheel 32 rotated by the motor 30.
(See FIG. 6). A rack 7a is formed in a vertical direction on the outer periphery of the outer cylinder member 7 constituting the cylindrical frame 6a, and the worm wheel 32 meshes with the rack 7a. The outer cylinder member 7 is supported by a retainer 29 so as to be able to move up and down.

The R-axis drive mechanism 13 comprises an R-axis motor 35 fixed on the upper part of the cylindrical frame 6a, and a first gear 37 rotated by the R-axis motor 35 via a bevel gear train 36.
And The first gear 37 meshes with a second gear 38 fixed to the upper end of the inner cylinder member 8. A bearing 9 is arranged between the outer cylinder member 7 and the inner cylinder member 8 so as to be rotatable with each other.

Further, the A-axis drive mechanism 14 includes an A-axis motor 40 fixed to the upper end of the cylindrical frame 6a,
And a rotating shaft 41 penetrating through the center of the rotating shaft. The rotating shaft 41 is rotated by a motor 40. A third gear 42 is fixed to a lower end of the rotating shaft 41, and the third gear 42 is meshed with a fourth gear 43,
The fourth gear 43 and the worm 44 are connected so as to rotate integrally. The fourth gear 43 is rotatably supported by a support plate 46 supporting the lower plate 45 and the upper frame 6b fixed to the lower end of the inner cylinder member 8. The lower end of the rotating shaft 41 holds a support plate 46. The rotation shaft 41 and the support plate 46 are rotatable. The upper frame 6b is supported below the support plate 46 via a shaft 47. A worm wheel 48 meshing with the worm 44 is fixed to the shaft 47. When the worm wheel 48 rotates, the upper frame 6b
Rotate in the A-axis direction.

As shown in FIGS. 3 and 4, the B-axis driving mechanism 15 includes a B-axis motor 50 fixed to the lower frame 6c.
And a fifth gear 5 rotated by the B-axis motor 50
It has a first and sixth gear 52, a worm 53 that rotates with the sixth gear 52, and a worm wheel 54. The worm wheel 54 is fixed to a shaft 55,
Further, the shaft 55 is fixed to the lower frame 6c. Therefore, the rotation of the worm wheel 54 causes the lower frame 6c to rotate in the B-axis direction. The lower frame 6c and the upper frame 6b are rotatable by a shaft 55. Further, the sixth gear 52 and the worm 53 are
6, and is rotatably supported by a part of the lower frame 6c.

The probe device 2 is fixed to the lower end of the lower frame 6c via a mounting member 60, and includes a centrally located measurement probe 61 and a measurement probe 4 disposed around the measurement probe 61. And the correction probes 62a to 62d. The measurement probe 61 is used as a normal flaw detection probe. Further, the correction probes 62a to 62d are closely arranged around the measurement probe 61 in a uniform manner.
It is used to control the transmission / reception angle of the ultrasonic beam based on the processing result of the reflected echo signal received by each of the probes 62a to 62d, that is, the time (distance) from transmission to reception of each probe. Can be

The flaw detector main unit 1 includes a CPU, a ROM, and a RAM.
And a control unit 65 including a microcomputer having the same. The control unit 65 includes a transmission unit 66, a reception unit 67,
The transmission / reception switching unit 68 and the probe switching unit 69 are connected. The control unit 65 drives a key input unit 70 in which keys and the like for inputting measurement conditions and the like are arranged, a display unit 71 including a CRT and the like for displaying a flaw detection result, and each of the driving mechanisms 10 to 15. A drive circuit unit 72 for control is connected. The transmission unit 66 includes a delay circuit, a pulsar, and the like. The receiving section 67 includes a detection circuit and the like. The transmission / reception switching unit 68 is for connecting the probe device 2 to one of the transmission unit 66 and the reception unit 67. The probe switching unit 69 includes a transmitting unit 66.
And one of the receiving unit 67 and one of the measurement probe 61 and the correction probes 62a to 62d.

The ultrasonic flaw detector 1 of the present embodiment includes a controller 65
And operates as described below. FIGS. 7 and 8 are control flowcharts. When the start switch is turned on, first, in step S1, initialization is performed. In this initial setting, each driving mechanism 1
Processing such as setting 0 to 15 as the initial position is performed. next,
In step S2, it is determined whether or not the start key has been pressed by the operator. If the start key has not been pressed, the flow shifts to step S3 to determine whether a key input for setting a condition has been performed. If a key for setting conditions has been input, the process proceeds to step S4, and a condition setting process for measurement is executed according to the key input. If no key input has been made, the flow shifts to step S5 to judge whether or not an instruction for performing another process has been issued. If an instruction has been issued, the flow shifts to step S6 to execute a process corresponding to the instruction. Execute

If the start key for measurement has been pressed, the flow shifts to step S7 in FIG. In step S7, an origin movement command is output to the drive circuit unit 72. As a result, the driving of each of the driving mechanisms 10 to 15 is controlled, and the probe device 2 moves to the preset origin. Next, in step S8, a pulse (main pulse and correction pulse) is output to each probe in order to emit an ultrasonic beam from the measurement probe 61 and the correction probes 62a to 62d. Here, in this case, the transmission / reception switching unit 68 is switched to the transmission unit side, and the probe switching unit 69 is switched in a time division manner. After each pulse is output, the transmission / reception switching unit 68 receives the reflected echo.
Is switched to the receiving unit side. In step S9, the focus distance is calculated from the reflected echo signal for the ultrasonic beam in step S8. In step S10, it is determined whether or not the focus distance is a preset distance. If the focus distance is not within the allowable range, the process shifts to step S11 to control the Z axis drive mechanism 12. Thereby, the rotation of the Z-axis motor 30 is controlled, and the probe device 2
Goes up and down. Steps S8 to S11 are repeatedly executed until the focus distance falls within the allowable range.

If it is determined that the focus distance is within the allowable range, the process proceeds from step S10 to step S12.
Move to In step S12, first, in order to measure the inclination of the probe device 2, a correction pulse is output, and the correction ultrasonic beams are sequentially transmitted and received from the correction probes 62a to 62d. Next, in step S13, each correction probe 6
From the processing results of the reflected echo signals obtained by 2a to 62d, the time from transmission to reception in each probe is obtained, and the inclination of the probe device 2 is calculated. Step S14
Then, based on the result of the calculation in step S13, it is determined whether or not the ultrasonic beam is irradiated perpendicularly to the search surface of the sample. If the inclination is out of the allowable range, step S15
Then, the A-axis drive mechanism 14 and the B-axis drive mechanism 15 are controlled. Thereby, the A-axis motor 40 and the B-axis motor 5
The rotation of 0 is controlled, and the inclination of the probe device 2 is controlled.
Step S until the inclination of the probe device 2 falls within the allowable range.
The processing from step 12 to step S15 is repeatedly executed.

If it is determined that the inclination of the probe device 2 is within the allowable range, the process proceeds from step S14 to step S1.
Move to 6. In step S16, a main pulse is output, and an ultrasonic beam is emitted from the measurement probe 61 to the sample 4. In step S17, measurement for normal flaw detection is performed based on the reflected echo signal from the sample 4. Next, in step S18, the X and Y drive mechanisms 10 and 11 are driven and controlled to scan at different positions, and the probe device 2 is moved to a new search surface of the sample 4. In step S19, it is determined whether or not the measurement has been completed. If the measurement has not been completed, the process returns to step S8 to repeat the above-described processing. If it is determined that the process has been completed, the process returns to step S3.

In such an embodiment, the correction probe 62
Since a to 62d are provided to automatically correct the inclination of the probe device 2 during measurement, it is not necessary to perform a troublesome operation such as teaching in advance. In addition, highly accurate measurement can be performed. Further, the correction probes 62a-
Since 62d is provided integrally with the measurement probe 61, it becomes compact.

[Other Embodiments] (a) In the above embodiment, four correction probes are provided, but the number of correction probes is not limited to the above embodiment.
For example, one correction probe may be arranged adjacent to the measurement probe, and a plurality of correction ultrasonic beams may be emitted while rotating the probe to perform the tilt calculation.

(B) The drive mechanism for each axis is not limited to the configuration of the above-described embodiment, but can be variously modified.

[0029]

As described above, in the first invention, the work such as teaching is not necessary in advance, and the measurement can be performed accurately while automatically correcting the inclination during the measurement. In the second aspect, the inclination of the probe can be measured with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an ultrasonic flaw detector according to one embodiment of the present invention.

FIG. 2 is a perspective view of a scanner of the ultrasonic flaw detector.

FIG. 3 is a front view of a flaw detector holding unit of the ultrasonic flaw detector.

FIG. 4 is a side view of the flaw detector holding unit.

FIG. 5 is a bottom view of the probe device.

FIG. 6 is a schematic diagram of a driving mechanism of each axis of the scanner.

FIG. 7 is a control flowchart of the flaw detector.

FIG. 8 is a control flowchart of the flaw detector.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 flaw detector main body 2 probe device 3 scanner 4 sample 61 measurement probe 62 a to 62 d correction probe 65 control unit 66 transmission unit 67 reception unit 71 display unit

Claims (2)

(57) [Claims] An ultrasonic flaw detector for detecting a defect of a sample by an ultrasonic beam, wherein a transmitting and receiving angle is variable, and a main transmitting and receiving unit for transmitting and receiving an ultrasonic beam for detecting the sample. And transmitting and receiving an ultrasonic beam for measuring an angle of transmission and reception of the ultrasonic beam, which is arranged uniformly in close contact with the periphery of the main transmitting and receiving unit.
Transmitting / receiving means having two sub-transmitting / receiving sections; a transmitting / receiving means for providing a drive signal for transmitting an ultrasonic beam to the transmitting / receiving means, and processing a reflected signal from the transmitting / receiving means; and Display means for displaying the processing result of the sample, based on the processing result in the transmitting and receiving means, whether the angle of the ultrasonic beam transmitted from the transmitting and receiving means with respect to the search surface of the sample is perpendicular or not, Judgment means for judging during the exploration, Angle control means for controlling the transmission and reception angle of the ultrasonic beam transmitted from the transmission and reception means with respect to the sample based on the result of the judgment means during the exploration of the sample, Ultrasonic flaw detector equipped with. 2. An ultrasonic probe used for an ultrasonic flaw detector for detecting a defect of a sample by an ultrasonic beam, wherein the main transmitting / receiving section transmits and receives the ultrasonic beam for detecting the sample. And four sub-transmitting and receiving sections for transmitting and receiving an ultrasonic beam for measuring the transmitting and receiving angle of the ultrasonic beam during the exploration of the sample, wherein the four sub-transmitting and receiving sections are arranged uniformly in close contact with the periphery of the main transmitting and receiving section. A probe for an ultrasonic flaw detector, comprising: