JP2758970B2 - Ultrasonic flaw detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to, for example, an ultrasonic flaw detector which detects ultrasonic waves by injecting ultrasonic waves into a test material and displaying a reflected wave from the test material to detect a defect. It relates to a flaw detection test based on a comparative test piece.

[Related Art] The test material 4 made of a forged product such as a rotor shaft of a turbine or a generator, or a vehicle axle has a complicated shape, and when ultrasonic waves are incident for a flaw detection test, it is caused by the shape together with a defect echo. An echo occurs.

FIG. 5 is a block diagram of, for example, a conventional ultrasonic flaw detector, wherein 1 is a synchronous signal generator for generating a synchronous signal at a fixed period, 4 is a test material, 21 is an ultrasonic wave transmitting device synchronized with the synchronous signal. A first transmission circuit for energizing waves, a second transmission circuit for energizing ultrasonic waves in synchronization with a synchronization signal, and a first transmission circuit for energizing ultrasonic waves
A first probe for transmitting / receiving ultrasonic waves by the bias of 21;
Reference numeral 24 denotes a second probe for transmitting / receiving ultrasonic waves by the bias of the second transmission circuit 22, reference numeral 25 denotes a comparative test piece having a material and shape similar to that of the test material 4, and reference numeral 26 denotes a first probe. A first receiving circuit for receiving a signal from the probe 23, a second receiving circuit 27 for receiving a signal from the second probe 24, and a first receiving circuit 26 and a second receiving circuit 28 for receiving a signal from the second probe 24.
This is a display for displaying a signal from the receiving circuit 27.

The conventional ultrasonic flaw detector is configured as described above,
The first probe 23 energized by the transmission circuit 21 is brought into contact with the reference test piece 25 serving as a reference via a couplant, and ultrasonic waves are incident thereon. First
The signal is received by the receiving circuit 26 and applied to the display 28.

The second probe 24 energized by the second transmission circuit 22 operating in synchronization with the first transmission circuit 21 abuts on the test material 4 via the couplant to receive ultrasonic waves and reflect the ultrasonic waves. The signal or echo is received by the second transmission circuit 27 and applied to the display 28. On the display 28, the reference echo from the comparative test piece 25 and the echo reflected from the test material 4 are displayed on their respective time axes.

FIG. 6 is an example of an echo display in a conventional flaw detection test, where is a transmission pulse, is a bottom echo, is a fixed echo, is a defect echo, is a reference echo from a comparative test piece 25 having a similar material and shape to the test material 4. Are echoes reflected from the test material 4.

The reference echo and the echo received based on the ultrasonic waves incident in synchronization with each other are displayed on the time axis of the same sweep speed provided in parallel. In the test material 4 of a forged product having a complicated shape, a fixed echo is generated by reflection from a step due to the shape of the test material 4 in addition to a transmission pulse and a bottom echo. In order to facilitate detection of the defect echo, the two echoes are compared with each other, and the detection of the defect echo generated by the steel ingot, forging, heat treatment, and the like, that is, the generation position, the level and the waveform are detected.

[Problems to be Solved by the Invention] In the conventional ultrasonic flaw detector as described above, for example, when flaw detection is performed on a test material 4 of a forged product having a complicated shape, a fixed echo due to the shape is generated. As a result, it becomes difficult to identify and detect a defect echo. Therefore, a test is performed using the comparative test piece 25, and the result is simultaneously displayed on the same display 28 for comparison. At this time, two sets of the transmission circuit, the probe, and the reception circuit are provided, and the first probe 23 and the second probe 24 are brought into contact with the comparison test piece 25 and the test piece 4 to operate individually. The test is conducted through multiple people.

On the display 28, the reference echo and the echo from the test material 4 are individually displayed on a time axis provided in parallel, and since the time axes are separated from each other, the echo levels and waveforms of both can be correctly compared. Absent.

Further, it is difficult to identify and detect a minute defect echo buried in noise due to a difference between the two displays.

In addition, forged products have various defects such as abnormal segregation defects due to steel ingots, sand chips, cracks due to forging or heat treatment, and defects in the metal structure, so it is not possible to efficiently distinguish between fixed echoes and defect echoes. In addition, there is a problem that it takes time to investigate the type and properties of the defect and to detect the defect position.

The present invention has been made to solve such a problem. The test of the comparative test piece 25 and the test material 4 can be performed by a simple operation using a device having a simple configuration. The object of the present invention is to provide an ultrasonic flaw detector which can quickly and accurately compare the echoes and can efficiently identify and detect defects in the test material 4.

[Means for Solving the Problems] An ultrasonic flaw detector according to the present invention detects ultrasonic waves by injecting ultrasonic waves toward a test material at a constant period and displaying echoes reflected from the test material to detect defects. In ultrasonic testing equipment,
A memory for storing a reference echo obtained by performing a flaw detection test on a comparison test piece having a material and a shape similar to the material to be inspected, a reference echo that operates at each interval of the period and is read from the memory, and A switch for alternately selecting the echo reflected from the test material, a color discriminating circuit that receives the reference echo and the echo reflected from the test material and outputs a signal that is individually color-sorted, A color display for alternately displaying, on the same time axis, a reference course and an echo reflected from the test material, which are selected by the switch for each period of the cycle and color-divided by the color discrimination circuit. It is characterized by the following.

[Action] In the present invention, a reference echo obtained by performing a flaw detection test on a comparative test piece having a material and a shape similar to the test material is stored in the memory, and the echo reflected from the test material and the reference echo are stored in the memory. The read reference echo and the read reference echo are alternately selected, color-divided by a color discrimination circuit, and color-displayed on the same time axis of the color display.

The level and waveform of the reference echo and the echo displayed in color on the same time axis can be quickly and accurately compared with each other, and the defect echo of the test material and the fixed echo can be easily distinguished. Since the reference echo and the echo reflected from the test material are alternately displayed by a switch that operates at every interval of the ultrasonic wave incident cycle, the echo reflected from the test material is stored in a memory or the like. There is no need to store it, the configuration of the device becomes very simple, and the device can be provided at low cost.

In flaw detection tests of forged products such as turbines, generator rotor shafts, and vehicle axles with complex shapes, steel ingots, forgings,
Defects generated due to heat treatment or the like can be correctly detected.

Further, it is possible to easily detect a minute defect buried in noise.

As described above, a flaw detection test using a device having a simple configuration can be efficiently performed by a simple operation.

Embodiment An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. Reference numerals 1, 4, and 25 are the same as those of the above-described conventional device, and reference numeral 2 is a transmission circuit for energizing ultrasonic transmission in synchronization with a synchronization signal. 3 is a probe for transmitting / receiving ultrasonic waves, 5 is a receiving circuit for receiving a signal from the probe 3, 6 is a microcomputer, 7
Is an input / output circuit, 8 is a central processing unit, 9 is a RAM of a writable and readable memory, 10 is a ROM of a read-only memory,
11 is a clock oscillator that outputs a clock pulse, 12 is a switching circuit that divides a synchronization signal and outputs a switching signal at every division, 13 is a switch operated by the switching circuit 12, 14 is an A / D circuit, and 15 is an A / D circuit. Denotes a D / A circuit, 16 denotes a color discriminating circuit for performing color classification of the echo reflected from the test material 4 output from the receiving circuit 5 and the reference echo read from the RAM 9, and 17 denotes a color display. .

In the ultrasonic flaw detector configured as described above,
The transmitting circuit 2 generates a pulse for energizing the probe 3 according to the synchronizing signal from the synchronizing signal generator 1. When an ultrasonic wave enters the test material 4 from the probe 3, the echo reflected from the test material 4 is received by the receiving circuit 5.

Fig. 2 shows an example of flaw detection for forging as a test material.
, Are the same as the conventional device. For example, when ultrasonic waves are incident in the axial direction from one end of the axle of the vehicle, the steps used for the wheel seat, gear seat, bearings, etc. are formed on the outer peripheral surface. The reflected wave from the laser beam becomes a fixed echo and forms an echo together with the bottom echo and the defect echo.

The switching circuit 12 receives the signal from the synchronization signal generator 1 and
The switch 13 is operated every time the synchronization signal is divided. The microcomputer 6 operates in synchronization with the synchronizing signal,
5 The reference echo subjected to the flaw detection test has a predetermined speed (for example, about 1
After sampling at 5 MHz, the data is quantized by the A / D circuit 14 and stored in the RAM 9 of the memory in advance. The reference echo stored in the RAM 9 is read out in response to a command from the clock oscillator 11 in synchronism with the switch 13 that operates at every division of the synchronization signal, and is read out and converted into an analog signal through the D / A circuit 15 to be converted into a color signal. It is added to the corresponding circuit (for example, red R) of the discrimination circuit 16. The receiving circuit 5
The echo reflected from the test material 4 after passing through the switch 13 is applied to a corresponding circuit (for example, green G) of the color discrimination circuit 15.
The output classified by the color discriminating circuit 16 is connected to a corresponding circuit of a color display 16 such as a color liquid crystal panel driven by scanning and arranging a color CRT or R, G, B color filters, on the same time axis. The reference echo and the echo reflected from the test material 4 are alternately displayed at every interval of the synchronization signal.

FIG. 3 shows an example of the flowchart, where P1 is the test material 4
A reference echo obtained by performing a flaw detection test on a comparative test piece 25 having a material and a shape similar to those of the above is stored in the RAM 9.

P2 performs a flaw detection test on the test material 4 in synchronization with the synchronization signal, and receives an echo reflected from the test material 4.

In P3, the reference echo of the comparison test piece 25 and the echo from the test material 4 are selected in synchronization with the synchronization signal, and are displayed in color on the same time axis of the color display 17 via the color discrimination circuit 16.

FIG. 4 shows an example of a color display in the flaw detection test,
,... Are the same as those of the above-mentioned conventional apparatus, but indicate a reference echo read out from the memory and color-separated, an echo reflected from the test material 4 and color-separated, and the reference echo and the echo are color-separated and different. Since the different colors are displayed on the same time axis, the difference between the levels, waveforms and generation positions of both echoes can be accurately detected.

It is possible to quickly and accurately identify and detect a defect echo, such as an abnormal segregation defect, a sand defect, a crack defect, or a defect in a metal structure, generated in a forged product as the test material 4 from a fixed echo.

Also, minute defect echoes buried in noise can be clearly detected.

The reference echo and the echo from the test piece 4 are always displayed at every interval by the operation of the switch 13, but the operation of the switch circuit 12 is stopped and the switch 13 is operated to operate either the reference echo or the echo. Only one can be selected and displayed for observation.

[Effects of the Invention] As described above, the present invention provides a memory for storing a reference echo of a comparative test piece, a switch for switching between the echo reflected from the test material and the reference echo, and a color discrimination for color-separating the two echoes. Due to the simple structure of providing the circuit, the echo from the test material and the reference echo of the comparison specimen are color-coded and displayed in color on the same time axis, so that the configuration of the device is simplified and the operation can be performed easily, so flaw detection Testing can be performed efficiently.

The level and waveform of the reference echo and the echo displayed on the same time axis can be quickly and accurately compared.

Since the reference echo and the echo reflected from the test material are alternately displayed by a switch that operates at every interval of the ultrasonic wave incident cycle, the echo reflected from the test material is stored in a memory or the like. There is no need to store it, the configuration of the device becomes very simple, and the device can be provided at low cost.

The defect echo of the test material can be easily distinguished from the fixed echo.

There is an effect that minute defect echoes buried in noise can be clearly detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an example of flaw detection of a forged product as a test material, FIG. 3 is an example of a flowchart, and FIG. 4 is an example of color display in a flaw detection test. FIG. 5 is a block diagram of a conventional ultrasonic flaw detector, and FIG. 6 is an example of an echo display in a conventional flaw detection test. In the figure, 4 is the test material, 6 is the microcomputer,
7 is an input / output circuit, 8 is a central processing unit, 9 is RAM, 10 is RO
M and 11 are clock oscillators, 12 is a switching circuit, 13 is a switch, 1
4 is an A / D circuit, 15 is a D / A circuit, 16 is a color discrimination circuit, and 17 is a color display. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] An ultrasonic flaw detector which detects ultrasonic waves by injecting ultrasonic waves toward a test material at a constant period and displays echoes reflected from the test material to detect defects. A memory in which a reference echo obtained by performing a flaw detection test on a shape comparison test piece is stored, and a reference echo read out from the memory and operated at each interval of the period and an echo reflected from the test material are stored. And a color discriminating circuit that receives the reference echo and the echo reflected from the test material and outputs a signal that is individually color-separated, and the switching for each division of the period. A color display for alternately displaying, on the same time axis, a reference echo selected by the detector and color-separated by the color discrimination circuit and an echo reflected from the test material. apparatus.