JPS6130762A - Ultrasonic flaw detection method and apparatus - Google Patents

Abstract

PURPOSE:To enable to detect the presence of a surface defect at the joint part, by transmitting an ultrasonic wave to and receiving it from the joint part of a central flange from various angles on both sides tops of a base section of an object to be inspected to obtain echo information while positional information is found at transmitting and receiving points. CONSTITUTION:An ultrasonic beam BA1 is radiated to a groove 4 from an ultrasonic vibrator of an ultrasonic probe 13 at the axial position PA1 and the circumferential position QA1 at a distance lA1 from the center of a web 2 at a key groove section (corresponding to the flange joint part at the base section) 4 and the reflected beam BB1 received from a defect 5 with an ultrasonic vibrator of an ultrasonic probe 18 located at the position PB1 and QB1 to obtain peak values and beam course data while position data (lA1+lB1)/2 is obtained from a probe position detector. The probes 13 and 18 are also moved to the positions PA1, PAn, PB1 and PBn and QA1, QAn, QB1 and QBn respectively to obtain similar data while circumferential and axial sectional images are displayed on a CRT.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention provides an object to be examined, which is, for example, a turbine disk having a flange protruding from the upper surface of the base portion approximately at the center thereof, and an opening in the turbine disk. - Detection of defects occurring on the surface along the axial direction of the rotor shaft in the key groove portion of the fitting surface with the rotor shaft (corresponding to the base portion of the flange in the base portion), and the rotor at the tip of this planar defect. The present invention relates to an ultrasonic flaw detection method and apparatus for measuring positional changes along the axial direction, that is, the shape of planar defects.

[Technical background of the invention and its problems]

Conventionally, when testing the key groove part of the fitting surface of the turbine disk with the rotor shaft using the test object as shown in FIG. 8, as shown in the figure, wear was removed from the outside of the turbine disk 1. Probe drive device 7A extending on both sides of the sandwich,
Oblique angle probes 6A and 6B are attached to the tip of 7B, and the ultrasonic beam 8A is made incident on the key groove part 4 of the turbine disk 1, and the reflected echo 8B from the defect 5 is detected, and the defect tip foul echo and the key groove are detected. The depth of the defect 5 is measured from the beam path of the echo reflected from the ceiling.

However, in the above-described method, the total beam path length of the incident beam 8A and reflected echo 8B to the defect 5 becomes long, so noise echoes etc. due to the material of the targon disk 1 increase, and the keyway web It was difficult to detect shallow defects in the area.

Furthermore, the range in which the depth of defects under the web 2 can be measured depends on the thickness of the web 2 or the inner and outer diameter dimensions of the hub 3.
Therefore, it was difficult to measure the change in the defect position of the web 2, that is, the defect shape.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object thereof is to apply the flange to the root portion of the flange on the base of a subject having a flange protruding from the approximate center of the upper surface of the base. It is an object of the present invention to provide an ultrasonic flaw detection method and an apparatus therefor that enable easy and highly accurate flaw detection to determine the presence or absence of existing planar defects and to measure their shape.

[Summary of the invention]

The ultrasonic flaw detection device according to the present invention is arranged on both sides of the upper surface of the base part of the test object, which has a collar protruding from the approximate center of the upper surface of the base part, and the ultrasonic wave transmission and reception directions are left and right. A transmitting and receiving ultrasonic probe is provided with a pair of ultrasonic transducers that are symmetrical and have the same refraction angle; a probe moving section that moves in an extending direction along the flange and a direction perpendicular to this extending direction; a probe position detecting section that detects the respective positions of the transmitting and receiving ultrasonic probes; , transmitting and receiving ultrasonic waves from the right (or left) in the extension direction to the root portion of the flange in the base using one of the ultrasonic transducers of the transmitting and receiving ultrasonic probes. At the same time, using the other ultrasonic transducer of the transmitting and receiving ultrasonic probes, ultrasonic waves are transmitted and received from the left (or right) of the extension direction to the base of the flange to obtain ultrasonic echo information. Based on the obtained ultrasonic echo information and the probe position information from the probe position detection section, find the position information and shape information of the defect existing at the root of the flange in the base part, and calculate this information. and a main body for displaying, the ultrasonic echo information is obtained by transmitting and receiving ultrasonic waves from multiple directions on both upper surfaces of the base to the base of the flange, and the ultrasonic echo information is displayed. The present invention is characterized in that the base portion of the flange portion is subjected to ultrasonic flaw detection by knowing the positional information of the transmitting and receiving points when transmitting and receiving ultrasonic waves from multiple directions.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the ultrasonic flaw detection apparatus of this embodiment. FIG. 2 (a>(b) is the ultrasonic probe of this example,
FIG. 2 is an axial cross-sectional view and a view from above when a probe moving section, a probe position detecting section, etc. are arranged on the same axis on a hub 3 sandwiching a web 2 of a turbine disk 1. FIG.

In FIG. 1 and FIGS. 2(a) and (b), 10 is a first motor consisting of a motor, etc. Second driving means 11A.

11B and is disposed on the hub 3, and is moved in the circumferential direction S on the hub 3 by the first driving means 11A.
It is configured to be movable. 12A and 12B are the first. This is a second encoder, and detects the position of the probe moving unit 10 by the first encoder 12A. 13 is the probe moving part 1
0 and is a transmitting ultrasonic probe that is movable in the axial direction A of the hub 3 on the probe moving unit 10 by a second driving means 11B. The position of this ultrasonic probe 13 is detected by a second encoder 12B. 14A and 14B are respectively provided in the probe moving section 10,
This is a limit switch that sets the origin when the ultrasonic probe 13 moves.

Here, the ultrasonic probe 13 includes a pair of ultrasonic transducers 13A.
, 13B, and these pair of ultrasonic transducers 13A, 1
3B is configured so that the swing angle θ and the refraction angle β are constant values. Further, in order to perform highly accurate flaw detection, the ultrasonic probe 13 is movable while being held with a constant pressing force against the hub 3 by the probe moving section 10.

Reference numeral 15 denotes a first motor including a motor and the like. second driving means 16A;
16B and is arranged on the same axis as the probe moving section 10 on the hub 3, and is moved in the circumferential direction S on the hub 3 by the first driving means 16-A. configured to be possible. 17A.

17B are the first and second parts provided in the probe moving section 15, respectively.
The position of the probe moving unit 15 is detected by the first encoder 17A. Reference numeral 18 denotes a transmitting ultrasonic probe provided in the probe moving section 15 and movable in the axial direction of the hub 3 on the probe moving section 15 by a second driving means 16B. The position of this ultrasonic probe 18 is detected by a second encoder 17B. Reference numerals 19A and 19B are limit switches provided in the probe moving section 15, respectively, for setting the origin when the ultrasonic probe 18 is moved. Here, ultrasonic probe 1
8 is a pair of ultrasonic transducers 18A.

18B, and a pair of ultrasonic transducers 18A.

18B is configured such that the swing angle θ and the refraction angle β are constant values. Further, in order to perform high-precision flaw detection, the ultrasonic probe 18 is movable while being held with a constant pressing force against the hub 3 by a probe moving section 15.

20 each ultrasonic transducer 13A, 13 of the ultrasonic probe 13
This is a transmitter that selectively applies high voltage pulses to B for transmission. 21 each ultrasonic transducer 18A of the ultrasonic probe 18;
This is a receiver that receives reflected echo signals selectively obtained from 1'8B and amplifies them to a predetermined signal level. 22 is a signal processor that calculates the peak value and beam path length of the reflected echo signal from the receiver 21 and converts it into a digital signal.

23 is a microcomputer that provides the transmitter 20 with a signal for controlling the ultrasonic excitation timing.

Reference numeral 24 receives a signal for controlling the ultrasonic excitation timing from the microcomputer 23 via the controller 25, and inputs a movement pattern in the circumferential direction $1 and the axial direction A of the probe moving section 10.15 that is stored in advance. (scanning method) and sends a command indicating the selected movement pattern (scanning method) to each first . Second driving means 11A.

11B, 16A, and 16B. This scanning method storage circuit 24 stores bits X1 and X in the axial direction A shown in FIG.
2, a command indicating a movement pattern (scanning method) of Y1.2, a pitch Y1.2 in the circumferential direction S shown in FIG. 3(b). A command indicating the movement pattern (scanning method) of Y2 is stored.

26 is each first .26 of the probe moving section 10.15. A probe position detection section that receives signals from the second encoders 12A, 12B, 17A, 17B and limit switches 14A, 14B, 19A, 1'9B and detects the position signal of the ultrasonic probe 13.1.8. be.

27 is a probe position detection unit 26 based on a signal from the microcomputer 23 that controls the ultrasonic excitation timing.
This is a memory that stores the position data from , and the peak value data and beam path data from the signal processor 22 corresponding to this position data as a measurement data group. Reference numeral 28 denotes a CRT (cathode ray tube) that displays images of the defect 5 in a B scope image and a C scope image based on the measurement data group from the memory 27. 29 is a display that numerically displays the measurement data group from the memory 27. 30 is a hard copy for recording on paper or the like the video display and numerical display displayed on the CRT 28 and two display devices.

Next, the operation of this embodiment configured as described above will be explained. That is, as shown in FIGS. 2(a) and 2(b), the ultrasonic probes 13 and 18 are located at axial positions PA1 and P at distances λAt and j2e from the center of the web 2 of the keyway 4, respectively.
The transmitter 20 sends a high voltage pulse to the ultrasonic transducer 13A of the ultrasonic probe 13 based on a signal from the microcomputer 23 that controls the ultrasonic excitation timing. and radiates the ultrasonic beam BAI to the keyway 4. As a result, the reflected beam BBI from the defect 5 is received by the ultrasonic transducer 18A of the ultrasonic probe 18 and taken into the signal processor 22 via the receiver 21. In this way the axial positions PAI, PB
When ultrasonic waves are transmitted and received at I, the flaw detection measurement position of the web 2 at this position becomes (2A1+2B1)/2, and as a result of this flaw detection, the position data (βA IB1)/2, peak value data and beam path data from the signal processor 22 are stored as a measurement data group.

Next, the microcomputer 23 operates the operating method storage circuit 24 via the controller 25 based on the signal for controlling the ultrasonic excitation timing, and the probe moving unit 10.1
5 second driving means 11B.

16B in the axial direction A by a predetermined pitch, and the ultrasonic probes 13 and 18 are moved to axial positions PAz and Pa at distances tliQA2 and λB2 from the center of the web 2 of the keyway 4, respectively.
Move to 2. Then, in the same manner as described above, a high voltage pulse is applied to the ultrasonic transducer 13A of the ultrasonic probe 13 by the transmitter 20, and the ultrasonic beam BA2 is emitted to the keyway 4.

As a result, the reflected beam BB2 from the defect 5 is received by the ultrasonic transducer 18A of the ultrasonic probe 18, is taken into the signal processor 22 via the receiver 21, and is sent to the probe position detection unit 26. Position data from (βA2+282)/2
, the peak value data and beam path data from the signal processor 22 are stored in the memory 27 as a measurement data group.

Repeating the above-mentioned operation, ie, ultrasonic probe 13.
18 each at a distance PAI from the center of the web 2 of the keyway 4
→PAa, Pat → PBrL (move to make ultrasound beam BAI, 8A2, ~, BAn, and reflect echo B
Position data (J2
A + +j2e + )/2, (+ = 1.2.~.
The microcomputer 23 stores the measurement data together with the peak value data and beam path data in the memory 27 as a group of measurement data, and then the microcomputer 23 controls the operation method storage circuit 24 via the controller 25 based on the signal that controls the ultrasonic excitation timing. to drive the first driving means 11A, 16A of the probe moving section 15 in the circumferential direction S by a predetermined pitch, and move the ultrasonic probe 13.1 in the axial direction A in the same manner as above.
Transmission and reception of ultrasonic waves is performed while moving 8. Then, the probe moving unit 10.15 (ultrasonic probe 13.18) is moved in the circumferential direction from QAI to QA n %QBI to QBn to perform so-called zigzag scanning and transmit and receive ultrasound. . Here, once the ultrasonic probe "13.18" passes through the center of the keyway 4, the direction of the ultrasonic beam is reversed instead of the ultrasonic transducers 13A and 18A in order to improve the resolution of flaw detection. Ultrasonic waves are transmitted and received using the ultrasonic transducers 13B and 18B.

By transmitting and receiving ultrasonic waves while performing the above-mentioned zigzag scanning and turning red, the CRT 28 displays the peak value of the reflected echo and the beam path corresponding to the probe position, as shown in Figure 4, for example. will be done. Also, CR
At T28, as shown in FIG. 5(a), a B scope image is displayed in the circumferential cross section of the keyway 2, and FIG.
As shown in b), it is possible to display a B-scope image in an axial section of the keyway 2. Furthermore, C
In RT2B, as shown in FIG. 6, it is possible to display a C-scope image of the keyway 2. Further, on the display 29, numerical data of the defect 5 obtained by signal processing is displayed.

As described above, according to this embodiment, the ultrasonic probes 13 and 18 perform zigzag scanning with respect to the keyway 2 under the control of the microcomputer 23 while transmitting and receiving ultrasonic waves. Since the scope image, C-scope image, and numerical data are displayed, it is possible to inspect the presence or absence of the defect 5 existing in the keyway 2, the dimensions of the defect 5, its shape, etc. in a short time and with high precision. becomes.

The present invention is not limited to the above embodiments, but for example, as shown in FIG.
By performing zigzag scanning G with the ultrasonic probes 13.18 synchronized with each other on 15A, the movement of the probe moving part 10.15 on the web 3 as shown in FIG. 2 is eliminated. In this way, flaw detection errors caused by movement on the web 3 may be reduced.

In addition, in this example, the object to be inspected is a turbine disk, and the key groove portion of the fitting surface of the turbine disk with the rotor shaft has been described, but the object to be examined is not limited to this, and the A flange is provided in a protruding manner at approximately the center of the upper surface, and is applied when performing ultrasonic flaw detection on the root portion of the flange in the base. In addition to the above, various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, according to the present invention, the flange is disposed on each of the upper surfaces of both sides of the base part of the subject, which has a flange protruding from the approximate center of the upper surface of the base part, and is arranged in the ultrasound transmission and reception direction. transmitting and receiving ultrasonic probes each having a pair of ultrasonic transducers that are bilaterally symmetrical and have the same refraction angle; a probe moving section that moves the transmitting and receiving ultrasonic probes in an extending direction along the flange of the section and in a direction perpendicular to the extending direction; and a probe position that detects the respective positions of the transmitting and receiving ultrasonic probes. Using the detection unit and one of the ultrasonic transducers of the transmitting and receiving ultrasonic probes, the base portion is located to the right (or left) of the base portion of the flange portion in the direction of extension. Ultrasonic waves are transmitted and received from the left (or right) of the extension direction to the base of the flange using the other ultrasonic transducer of the transmitting and receiving ultrasonic probes. Based on this ultrasonic echo information and the probe position information from the probe position detection unit, the position information and shape of the defect existing at the base portion of the flange portion in the base portion are obtained. It consists of a main body that obtains and displays information, and obtains ultrasonic echo information by transmitting and receiving ultrasonic waves from multiple directions on both upper surfaces of the base to the base of the flange. Since the base portion of the flange is ultrasonically detected by knowing the transmitting/receiving point position information when transmitting and receiving ultrasonic waves from multiple directions, the flange protrudes approximately at the center of the upper surface of the base. It is possible to provide an ultrasonic flaw detection method and an apparatus therefor that enable easy and highly accurate flaw detection to determine the presence or absence of a planar defect existing at the root of the flange in the base of the test object and to measure the shape with ease. .

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing main parts of the embodiment, FIG. 3 is a pattern diagram for explaining a scanning method storage circuit in the embodiment, and FIG. 4 to 6 are diagrams for explaining the operation of the same embodiment, FIG. 7 is a diagram for explaining another embodiment of the present invention, and FIG. 8 is a diagram for explaining the conventional ultrasonic flaw detection method. FIG. 10.15.10A, 15A... Probe moving part, 11
A, 11B, 16A, 16B...driving means, 12A,
12B, I 7A, 17B...Encoder, 13.1
8... Ultrasonic probe, 13A, 13B, 18A, 18
B... Ultrasonic vibrator, 14A, 148.19A, 19
B... Limit switch, 2o... Transmitter, 21.
...Receiver, 22...Signal processor, 23...Microcomputer, 24...Scanning method storage circuit, 25.
...Controller, 26...Probe position detection section, 27...
Memory, 28...CAR block, 29...Display unit, 3o
···hard copy. Applicant's agent Patent attorney Takehiko Suzue Figure 6 Figure 7 Figure 8

Claims (2)

[Claims] (1) In an ultrasonic flaw detection method for ultrasonic flaw detection of the root portion of the flange in the base of a specimen having a flange protruding from the approximate center of the upper surface of the base, Ultrasonic echo information is obtained by transmitting and receiving ultrasonic waves to and from the base of the flange from various directions, and by knowing this ultrasound echo information and the transmitting and receiving point position information when transmitting and receiving ultrasonic waves from multiple directions, An ultrasonic flaw detection method that detects ultrasonic flaws at the root of a part. (2) A flange is disposed on each side of the upper surface of the base of the subject having a flange protruding from the approximate center of the upper surface of the base, and the ultrasonic wave transmission and reception directions are symmetrical and have the same refraction angle. a transmitting and receiving ultrasonic probe equipped with a pair of ultrasonic transducers having a transmitting and receiving ultrasonic probe, each of which is extended along the flange of the base of the subject. a probe moving section that moves the ultrasonic probe in a direction perpendicular to the direction and the extension direction; a probe position detecting section that detects the respective positions of the transmitting and receiving ultrasonic probes; Ultrasonic waves are transmitted and received from the right (or left) in the extension direction to the base portion of the flange using one ultrasonic transducer of each of the ultrasonic probes. Using the other ultrasonic transducer of each ultrasonic probe, ultrasonic waves are transmitted and received from the left (or right) in the extension direction to the base of the flange to obtain ultrasonic echo information. a main body section that determines and displays position information and shape information of a defect existing at the base of the flange portion in the base section based on the information and the probe position information from the probe position detection section; An ultrasonic flaw detection device characterized by: