JPH1068716A - Manual ultrasonic flaw detection training equipment - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a practical training simulator to a person engaged in manual ultrasonic flaw detection to improve skill and work reliability. A plane coordinate detection device capable of scanning a probe by manual flaw detection is provided, and a flaw detection scan is performed on a test surface of a training simulator, and an ultrasonic output value of a material flaw input by simulation is based on personal skill. A manual ultrasonic flaw detection skill training simulator that corrects and displays the flaw detection state correction factor, displays the error evaluation of the ultrasonic flaw detection result, and outputs the factor analysis result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detection test, which is a type of nondestructive inspection, and relates to an individual difference of inspectors (manual flaw detection work) which has recently attracted attention in manual flaw detection work. The present invention relates to an inspector's skill training device for reducing human error and improving reliability.

[0002]

2. Description of the Related Art There is no apparatus suitable for training for improving the skill based on quantitative measurement and evaluation of the skill of manual flaw detection.

[0003]

According to the results of human error investigations conducted in Europe, it has been reported that human inspectors conducted manual inspections may cause human errors in the test results. However, until now, there was no training device that could quantitatively evaluate the skills of inspectors,
The inspectors themselves could not know the specific problems in their flaw detection skills, and could not carry out effective correction training.

[0004]

Means for Solving the Problems In order to achieve the above object, the following configuration is provided.

According to the first aspect of the present invention, a large number of linear grooves having a constant depth are provided on the bottom surface of a test piece in order to measure a change in a scanning state of a probe at the time of flaw detection. The echo height was measured. Based on the echo height, the reference flaw detection wave height read out from the flaw detection waveform database is automatically corrected and displayed on the display.

According to a second aspect of the present invention, a direct contact method and a gap method are used to measure and evaluate the scanning state of the probe according to the first aspect separately from the contact state of the probe and the direction of the probe. Using a composite probe that integrates the two transducers, the ultrasonic echo height obtained by each of them, or a device that calculates the ratio between them, and from them, the contact state and orientation stability of the probe It is composed of software that separately evaluates skills related to gender.

According to a third aspect of the present invention, in order to obtain the position coordinates of the ultrasonic probe during flaw detection scanning, two wire pull-out linear scale encoders are arranged at an arbitrary position, and the linear scale encoder is provided at the tip of the wire. It is composed of hardware to which an ultrasonic probe is connected and software for recording a flaw detection signal together with the obtained position coordinates.

A fourth aspect of the present invention is based on the first aspect of the present invention and comprises the apparatus of the third aspect and software for determining a scanning pitch from a flaw detection result obtained therefrom and evaluating a skill of the flaw detector.

The functions of various technical means for solving the above-mentioned problems are as follows.

According to the configuration of the first aspect, it is possible to correct the reference flaw detection waveform to the actual flaw detection state by using the echo heights of a large number of linear grooves provided on the bottom surface of the test piece. Specifically, when detecting a slit defect given to a test piece, the probe direction becomes maximum when the probe direction is perpendicular to this direction, and otherwise, the ultrasonic echo height monotonically changes with the angle. And the height of the ultrasonic echo changes depending on the thickness of the couplant between the probe and the flaw detection surface. Using this phenomenon, the reference flaw detection waveform is corrected, and the height of the defect waveform reflecting the degree of skill of the flaw detector is displayed on a monitor to enable the following flaw detection skill evaluation.

(1) The flaw detection waveform fluctuates and decreases depending on the skill of the flaw detector, so that the flaw detector's ability to detect a defect (oversight of a defect) can be evaluated.

(2) For the same reason, after detecting a defect, the ability of the flaw detector to measure and collect detailed data on the flaw detection can be evaluated by comparing it with a reference flaw detection waveform.

According to the second aspect of the present invention, it is possible to obtain a means for correcting the fluctuation of the probe scanning angle and the stability of the probe contact state performed by the flaw detector. Hereinafter, the reason will be specifically described. In the direct contact method, it is inevitable that the thickness of the couplant between the probe and the surface to be inspected fluctuates during the flaw detection scanning, so that the ultrasonic echo height also fluctuates. On the other hand, in the gap method, the film thickness is constant, and the fluctuation of the ultrasonic echo height is so small that it does not matter. This allows the following:

(1) The height of the ultrasonic echo from the straight slit by the gap method is an index of the change in the direction of probe scanning.

(2) The ratio of the respective echo heights of the direct contact method and the gap method serves as an index of the variation in the thickness of the couplant between the probe and the flaw detection surface.

These two indices indicate the skill of the flaw detector, and by using these to correct the reference flaw detection waveform, it is possible to obtain the actual flaw detection ultrasonic echo height taking into account the skill of the flaw detector.

According to the third aspect of the present invention, the position coordinates of the ultrasonic probe can be measured with a very simple configuration while maintaining the sense and freedom of manual flaw detection scanning.

According to the fourth aspect of the present invention, the scanning position coordinates of the probe obtained as described above are arithmetically processed to obtain a variation in the scanning pitch, and the skill of the flaw detector can be evaluated from this.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows the overall configuration of a manual ultrasonic inspection skill training apparatus according to the present invention. Two wire-drawing linear scale encoders 31 and 32 are installed at an arbitrary interval, and the tip of the drawn wire 30 is connected to the composite ultrasonic probe 11. The output of the encoder is recorded in the data recording processing device 39. The back surface of the test piece 20 is provided with a plurality of straight grooves having a constant depth. Probe 1
The ultrasonic echo detected in 1 is recorded in the data recording processing device 39 via the ultrasonic flaw detector 10. The test piece 20 does not include a material defect to be inspected other than the linear groove. The material defects are stored in the database as reference flaw detection waveform data, and are softly distributed and arranged as virtual defects in a range corresponding to the flaw detection surface of the test piece 20.
The flaw detector reads the reference flaw detection waveform data using the position coordinates of the probe as an address, performs flaw detection scanning while looking at the waveform displayed on the display, and records the defect echo height from the flaw detection waveform data. Recorded in the device 39.

Hereinafter, embodiments of the present invention will be described.

First, claim 1 will be described.

The ultrasonic flaw detection echo height changes depending on the contact state and orientation of the probe, even if the size of the target defect is constant. FIG. 2A shows an example in which the echo height changes depending on the direction θ of the probe. When the direction θ of the probe with respect to the straight groove 23 changes, the echo height h also changes. FIG.
(B) shows that the echo height changes with the contact state, that is, the thickness g of the couplant 112 changes. When the reference flaw detection waveform is displayed on the display and the defect echo height is recorded, the change must be corrected. In the present invention, the echo height from the straight groove is used as the correction data. FIG. 3 shows the processing flow.

In order to use the state of the probe which affects the height of the flaw detection echo as an index for evaluating the skill of the flaw detector, the influence of the thickness of the couplant and the orientation of the probe can be determined. The effect is measured separately for two items, and an example is shown in FIG.

FIG. 4A shows a direct contact probe 11c in which a probe is used in close contact with a flaw detection surface, and a gap type probe in which a minute gap is provided and the gap is filled with a couplant to be used. This shows a case where a straight groove is flaw-detected by a composite probe in which a probe 11g is integrated. The flaw detection echo height hc of the direct contact probe 11c is determined by the thickness gc of the couplant and the direction of the probe (θ in the figure).
However, as shown in FIG. 2B, the flaw detection echo height hg of the gap type probe is so small that the influence of the change of the gap gg is negligible. It is only affected by the probe orientation θ. Therefore, if Vg = hc / hg is calculated, Vg is in a contact state,
That is, it can be used as an index for evaluating the effect of the thickness of the couplant. From the echo height hg, Vθ = hg / h
If 0 is obtained, only the influence of the direction of the probe can be separated and evaluated from Vθ. That is, it is possible to analyze and evaluate in detail the problem of the flaw detection skill of the flaw detector regarding the state of the probe. FIG. 5 shows a data processing flow of this embodiment.

The operation of two wire pull-out linear scale encoders (hereinafter simply referred to as encoders) will be described with reference to FIG. In FIG. 6, the distance between the two encoders 31 and 32 and the triangular shape formed by the (X, Y) points of the probe 11 to which the lead wires 30 of the encoders are connected are shown. c, if the length of the wire 30 pulled out from the encoder 31 is a and the length of the wire of the encoder 32 is b, the position (X, Y) of the probe when the position of the encoder 31 is the origin. Can be obtained by the equations (1) and (2) in FIG. This makes it possible to measure the position of the probe that is scanned by freehand, which was conventionally difficult to measure. This method has an advantage that due to the flexibility of the wire, the measurement can be performed in a state close to the actual state without substantially restricting the degree of freedom inherent in manual scanning. By continuously displaying the measured probe positions, a scanning locus can be obtained. FIG. 7 shows an example of the display.

Next, a method of setting a virtual measurement line will be described as an embodiment of the method of measuring the probe scanning pitch according to the fourth aspect. The measurement results of the scanning trajectory of the probe by manual scanning are shown in FIG. 7, but which part of this figure is used as the scanning pitch also depends on the amount of data to be processed.
Consideration needed. In the present embodiment, as shown in FIG. 8, a virtual measurement line 85 is assumed, and the pitch is defined as an interval between intersections of the measurement line and the scanning trajectory. By moving the virtual measurement line or providing a plurality of measurement lines, it is possible to measure pitches having various meanings. If the number of virtual measurement lines is made equal to the number of data recording points in the Y direction, all data will be evaluated.

FIG. 9 divides the scanning range into four regions,
An example of the measurement of the average scanning pitch of each area when there are two virtual measurement lines is shown.

[0029]

The apparatus of the present invention makes it possible to accurately measure and evaluate the actual state of probe scanning in a manual ultrasonic flaw detection test, which was difficult to measure and evaluate in the past, and to perform correction training based on this. As a result, it has been clarified that the reliability of the inspection can be further improved. Further, the device for measuring and recording the probe position in the manual scanning provides a recording device in a normal flaw detection operation, and greatly contributes to improvement in operation efficiency.

[Brief description of the drawings]

FIG. 1 is a block diagram of a manual ultrasonic inspection skill training apparatus.

FIG. 2 is an explanatory diagram of the measurement of the direction of a probe based on the ultrasonic reflection characteristics of a straight groove and the influence of a gap.

FIG. 3 is a flowchart of a reference flaw detection waveform correction process.

FIG. 4 is an explanatory diagram of correction of a probe contact state by a direct contact method and a gap method.

FIG. 5 is a flowchart of processing for correcting a probe contact state by a direct contact method and a gap method.

FIG. 6 is an explanatory diagram of a probe position coordinate measuring principle.

FIG. 7 is an explanatory diagram of a probe scanning locus.

FIG. 8 is an explanatory diagram of an example of a probe scanning pitch measuring method.

FIG. 9 is an explanatory diagram of an example of a probe scanning pitch measurement result.

[Explanation of symbols]

10 ... ultrasonic flaw detector, 11 ... probe, 20 ... test piece, 3
1-33: Wire pull-out linear scale encoder, 8
1: scanning trajectory.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takagi Matsuo 3-2-1, Sachimachi, Hitachi-shi, Ibaraki Hitachi Engineering Co., Ltd. (72) Shinichi Higuchi 3-1-1 Sachimachi, Hitachi-shi, Ibaraki No. 1 Inside Hitachi, Ltd. Hitachi Plant

Claims (4)

[Claims] 1. A manual ultrasonic flaw detection technique in which an arbitrary defect is artificially distributed on a plane coordinate on a test object by a computer from a database containing various reference flaw detection waveforms, and the flaw is detected by a flaw detector. In the training device, a large number of straight grooves having a constant depth are provided in parallel on the back surface of the test piece to be used, and the ultrasonic flaw height from this groove corrects the reference flaw detection wave height read out from the database and displays it on the display. A manual ultrasonic flaw detection skill training device characterized by displaying. 2. The gap type probe according to claim 1, wherein when the reference flaw detection waveform is corrected based on a flaw detection state, a direct contact probe and a gap type probe that contact with a small gap are integrated on the surface of the test object. Flaw detection using a composite probe, evaluation of the contact state of the probe by the ratio of the ultrasonic echo height of both probes, and flaw detection using the ultrasonic echo height of the latter probe A manual ultrasonic flaw detection skill training device that evaluates skills related to directional stability. 3. A two-wire pull-out linear scale encoder is installed at an arbitrary interval on an inspection surface, and a scanning locus of an ultrasonic probe connected to an end of a wire of both encoders is calculated in plane coordinates. A plane coordinate detecting device for manual flaw detection, wherein a flaw detection signal is recorded together with the plane coordinates. According to a first aspect of the present invention, a scanning pitch is obtained based on a scanning trajectory of a probe obtained by the plane coordinate detecting device according to the fourth aspect, thereby enabling a quantitative evaluation of a flaw detection skill of a flaw detector. Manual ultrasonic inspection skill training equipment.