JPH01223343A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To enable proper detection of a defect even when an object to be detected is that having numerous steps or the like, by providing a time shaft section composed of a plurality of sweeping circuits, a selector switch and a sweep computation circuit. CONSTITUTION:An apparatus body 1 is composed of a transmitting section 11 for generating a pulse-like high voltage, a receiving section 12 which receives a voltage received with an ultrasonic probe 2 to perform an amplification, detection or the like, a Braun tube display section 16 and a time shaft section 20 for adjusting the time axis of the Braun tube display. Then, an expanded display of the overall length of an object 4 to be detected is made possible with a continuity with the action of a time shaft section 20, namely, a plurality of sweep delay circuits 21a, 21b... and 21g, a selector switch 22, a sweep computation circuit 23, a sweep generation circuit 24 and a sweep amplification circuit 25 thereby facilitating discrimination for the presence of a defect echo while achieving a higher accuracy of reading a position of generating an echo. This enables accurate detection of a defect even when an object to be detected is that having numerous steps.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an ultrasonic flaw detection method for non-destructively testing long shafts or long bolts in high-speed rotating equipment such as pumps and engines. Regarding equipment.

[Conventional technology]

FIG. 4 is a diagram showing a conventional ultrasonic flaw detection device 1. As shown in FIG. Fourth
As shown in the figure, a probe 2 is connected to the device 1 via a cable 3. The device 1 includes a time axis section 10 and a transmitting section 1.
1, a receiving section 12, and a cathode ray tube display section 16, and the time axis section 10 includes a sweep delay circuit 13. Sweep generation circuit 14
．． It is composed of a sweep amplification circuit 15.

When the time axis section 10 receives the synchronization signal from the transmitting section 11, the sweep delay circuit 13 adjusts the timing of the horizontal sweep of the cathode ray tube display section 16.
4 generates a sweep voltage, which is amplified by a sweep amplifier circuit 15 and input to a cathode ray tube display section 16. The cathode ray tube display section 16 displays information from the receiving section 12 based on the signal from the time axis section 10.

FIG. 5 is a diagram showing the subject 4 and the display screen of the cathode ray tube display section 16 together. As shown in FIG. 5, reflected waves are displayed on the cathode ray tube display screen M (N). Note that the horizontal axis represents the ultrasonic propagation time, and the vertical axis represents the intensity of reflected waves. In Fig. 5, 4a to 4f indicate the stepped portions of the object 4 on the axis, 4g indicates defects on the object 4, and a-f and g indicate the reflected waves corresponding to the stepped portions and defects. There is.

Note that 2 indicates a transverse wave vertical probe. The display as shown in FIG. 5 is called the A-scope, and the inspector uses this A-scope as a monitor during inspection.

Figure m6 is a diagram showing the time relationship of signals in the cathode ray tube display section 16, where X is a synchronization signal, Y is a sweep delay signal, and Z
M and ZN are sweep generation signals. ZM is a case where the length of the subject 4 is short, and the slope of the triangular wave is large. Also Z
N is a case where the length of the subject 4 is long, and the slope of the triangular wave is small. ZM.

Adjustment between ZN can be made according to the length of the object 4 using a volume on a panel on the front of the main body of the flaw detector. Also, when the length of the test object 4 is long, the test object 4
If it is desired to enlarge and monitor a specific portion of the image, the timing of the sweep delay is delayed to generate a triangular wave with a large slope such as ZM.

[Problem to be solved by the invention]

When using a conventional ultrasonic flaw detection device to inspect a test object 4 consisting of a long shaft with a step as shown in Fig. 5 by vertical flaw detection from the end face, the following problems occur. Ta.

(1) If an attempt is made to monitor the entire length of a long object 4, the object will be greatly reduced. That is, the horizontal axis of the cathode ray tube display section 16 is generally about 100B, and the
If the length is 2 m, the display scale will be 1/10. Therefore, as shown in the display screen M of FIG. 5, shape echoes b, c, and d are generated.

A large number of echoes e appear, making it very difficult to decipher the presence or absence of defective echoes g.

(2) It is necessary to record the position of the defect 4g as an inspection record, but because the reduction ratio of the display is large, the accuracy of reading the echo generation position is poor (the horizontal axis of a cathode ray tube is generally 100
equal division scale).

(3) In order to make it easier to read defective echoes, it is possible to display a partially enlarged display like the display screen N shown in Figure 5. However, when such a partially enlarged display is performed, it becomes difficult to read the echo generation position. The origin (distance from 4a in the figure) becomes unclear.

As described above, when the conventional ultrasonic flaw detection device 1 is used to inspect long shafts with steps, it is inconvenient and difficult to detect flaws, and there is a risk that inspectors may make judgment errors. .

It is important to ensure the safety of the main shafts of high-speed rotating equipment such as large pumps against destruction. For this reason, various inspections are carried out during manufacture of the spindle to ensure quality, and disassembly and inspection are also carried out after the start of operation. However, the outer circumferential surface of this main shaft has many steps and is covered with another wheel that is shrink-fitted. Therefore, there are great expectations for ultrasonic flaw detection as a means of inspection.

However, for the reasons mentioned above, it has been practically impossible to perform ultrasonic flaw detection. Therefore, the emergence of an ultrasonic flaw detection device that solves these problems has been awaited.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an ultrasonic flaw detection device that can accurately detect defects even if the object to be inspected has many steps.

[Means to solve the problem]

The present invention has taken the following measures to solve the above problems and achieve the objectives. In other words, there is a transmitting section that generates a pulsed high voltage, a time axis section that sweeps the signal from the transmitting section, a receiving section that receives the signal received by the probe, and a time axis section that receives the signal from the receiving section. A display section that displays a display based on a signal from an axis section, and the time axis section includes a plurality of sweep circuits, a changeover switch that sequentially switches these sweep circuits, and a timing of sweep delay and sweep generation. It consists of a sweep calculation circuit that calculates and controls the

[Effect]

By taking the above measures, the following effects are achieved.

It is possible to continuously enlarge parts of the A scope at specific steps, making it easier to decipher the presence or absence of defective echoes.
Moreover, the accuracy of reading the echo generation position is improved.

〔Example〕

An embodiment of the present invention will be described with reference to FIG. Reference numeral 1 denotes the main body of the ultrasonic flaw detection device, which includes a transmitting section 11 that generates a pulsed high voltage, a receiving section 12 that performs amplification or detection upon receiving the voltage received by the ultrasonic probe 2, and a cathode ray tube display section. 16, and a time axis section 20 for adjusting the time axis of cathode ray tube display, which is the key point of the present invention.

The time axis section 20 includes a plurality of sweep delay circuits 21a.

21b, 21c...21g, the changeover switch 22,
It consists of a sweep calculation circuit 23, a sweep generation circuit 24, and a sweep amplification circuit 25. Although this example has a seven-channel sweep delay circuit, the number of channels needs to be increased depending on the purpose of the inspection and the length of the object.

Next, the operation of this embodiment will be explained. FIG. 2 is a diagram showing a test object 44 at a stepped portion and a flaw detection pattern displayed on the cathode ray tube display section 16 while the test object 44 is being inspected. This shows the A scope waveform corresponding to the shape of the subject 4. M and A, B.

C and D show A scope images displayed on the cathode ray tube 16. When the vertical probe 2 is pressed against one end surface 4a of the object 4 via a special couplant material (not shown), in addition to echoes from the other end surface 4f of the object 4, a stepped portion 4 whose diameter becomes smaller is generated.
Echoes be from b, 4c, 4d, and 4e occur. Note that if there is a defect 4g between the step portions 4C and 4d, an echo g thereof appears. Further, M is a case where the entire length of the subject 4 is displayed on the cathode ray tube display section 16, and the length scale of the subject 4 is displayed in a very reduced state. Note that this display is similar to that displayed on the cathode ray tube display section of a conventional ultrasonic flaw detector.

Furthermore, A, B, C, and D shown in FIG. 2 are displayed by dividing the entire length of the subject 4 into equal parts by the function of this device, and by switching the changeover switch 22 shown in FIG. , sweep delay circuits 21a, 21b.

21c...21g are connected in sequence, and the timing of the sweep delay is switched to a state delayed by a certain period of time.

Note that there is a sweep calculation circuit 23 between the sweep generation circuit 24 and the changeover switch 22, and the operation of this sweep calculation circuit 23 calculates the timing of the sweep delay and sweep generation. The entire length of the subject 4 is displayed in an enlarged manner on the blank tube display section 16 while maintaining continuity.

The above example shows an example in which the total length of the subject 4 is divided into four and enlarged, but when the total length of the subject 4 is long, it is more effective to increase the number of divisions. For example, the total length of subject 4 is 5111
If a 20-channel sweep delay circuit is provided, 20 times of display can be performed when the display is divided to the maximum, and by switching the switch 22, the display can be performed from 0 to 250 m, from 250 u to 250 m.
500u.

. . , 4750 m to 5000 mm, etc., are enlarged and displayed while maintaining continuity.

FIG. 3 is a diagram showing the time relationship of signals in the time axis section 20. CHM shows the time relationship of the synchronization signal X, sweep delay Y, and sweep generation 2 signals corresponding to the display screen M shown in FIG. 2 when the entire length of the subject 4 is displayed.

Furthermore, CHA, CHB, CHC, and CHD in the same figure indicate the case of split display, and the displays A, B, C, and D shown in FIG.
It shows the time relationship of the codes corresponding to . YA, YB,
YC and YD indicate the sweep delay of each channel. ZA again.

ZB, ZC, and ZD indicate sweep generation signals.

Note that it is divided into equal parts and continuously enlarged, so (tz-tt
)-(t3-t2)-(t4-t3).

According to this embodiment, the multi-channel sweep delay circuit 21a
21g, the changeover switch 22, and the sweep calculation circuit 23, the entire length of the subject 4 can be continuously enlarged and displayed. Therefore, when inspecting a shaft neck having a step, etc., the accuracy of reading defect echoes and echo generation positions is improved. Therefore, it is possible to inspect long shaft necks or long bolts with steps.

Note that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, it is possible to continuously enlarge and display a portion of the A scope in a specific step, so it becomes easy to determine the presence or absence of a defective echo, and the accuracy of reading the echo generation position is improved. In this way, it is possible to provide an ultrasonic flaw detection apparatus that can accurately detect defects even if the object to be inspected has many steps.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing one embodiment of the present invention. Figure 1 is a diagram showing the configuration of an ultrasonic flaw detection device, and Figure 2 is a diagram showing an object to be examined consisting of a stepped shaft and its flaw detection results. FIG. 3 is a diagram showing the waveform of the reflected wave displayed on the cathode ray tube display section based on the above-mentioned data, and FIG. 3 is a diagram showing the time relationship of the signals in the time axis section. Figures 4 to 6 are diagrams showing conventional ultrasonic flaw detection equipment.
The figure shows the configuration of the ultrasonic flaw detection device, Figure 5 shows the test object consisting of a stepped shaft and the waveform of the reflected wave displayed on the cathode ray tube display based on the flaw detection results.
The figure is a diagram showing the time relationship of signals on the time axis. 1... Ultrasonic flaw detection device main body, 2... Probe, 3...
・Cable, 11... Transmitting section, 12... Receiving section, 1
0゜20... Time axis section, 21a-21g... Sweep delay circuit, 21... Changeover switch, 23... Sweep calculation circuit, 14.24... Sweep generation circuit, 15.25.
...Sweep amplification circuit, 16...Cathode-ray tube display section. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A transmitting section that generates a pulsed high voltage, a time axis section that sweeps the signal from the transmitting section, a receiving section that receives the signal received by the probe, and a signal from the receiving section that sweeps the signal from the transmitting section. a display section that displays based on a signal from a plurality of sweep circuits; and a time axis section that calculates a plurality of sweep circuits, a changeover switch that sequentially switches these sweep circuits, and a timing of sweep delay and sweep occurrence. 1. An ultrasonic flaw detection device comprising: a sweep calculation circuit that performs control using a sweep calculation circuit;