JPH0160778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an ultrasonic axle flaw detection device for investigating the presence or absence of flaws, cracks, etc., and their positions on a vehicle axle.

Prior Art As shown in FIG. 1, a conventional ultrasonic axle flaw detection device includes a transmitter circuit 1, a transceiver probe 2, a receiver circuit 3, an analog-to-digital converter 4, a semiconductor memory 5, and a digital-to-analog converter. 6, Y-axis amplifier 7, synchronous circuit 8, sweep circuit 9, X-axis amplifier 1
0, cathode ray tube or CRT 11, and control circuit 12
The ultrasonic wave generated by the probe 2 is transmitted to the axle 1.
4 and the reflected waves obtained from the axle 14 are once stored in a semiconductor memory, and then drawn on the CRT 11 to non-destructively inspect the interior of the axle 14.

To explain in more detail the configuration and inspection method of each part, the transmitter circuit 1 is a pulse generator that generates electric pulses for generating ultrasonic pulses,
A pulse is supplied to the probe 2. The probe 2 for both transmitting and receiving waves includes a transducer for generating ultrasonic waves,
It generates ultrasonic pulses in response to electric pulses, and also receives reflected waves of the ultrasonic waves propagated through the axle shaft 14 and converts them into electric signals. This electrical signal is detected and amplified by the receiving circuit 3. The analog-to-digital converter, ie, the A/D converter 4, sequentially samples the analog received wave, which is the output signal of the receiving circuit 3, at a constant clock and converts it into a digital signal. A memory 5 provided next to the A/D converter 4 stores test data corresponding to waveforms. 6 is a digital-to-analog converter, that is, a D/A converter, and a memory 5
The test data obtained from the CRT 11 is converted into an analog signal for display on the CRT 11. A Y-axis amplifier 7 amplifies the output of the D/A converter 6 so as to display it on the CRT 11. The control circuit 12 sequentially controls the signal processing circuit 13 shown surrounded by a dotted line. The synchronization circuit 8 generates a trigger signal in response to a pulse generated from the transmission circuit 1. In response to this trigger signal, the sweep circuit 9 generates a sawtooth wave synchronized with the trigger signal, which is amplified by the amplifier 10 and applied to the horizontal deflection plate of the CRT 11. The output of the D/A converter 6 is applied to the vertical deflection plate of the CRT, and as a result, a part of the transmitted wave and the reflected wave are displayed on the CRT 11 as shown in FIG. It becomes possible to determine the location of the wound.

However, in cases where the shape of a vehicle axle is complex and various parts are attached to the side, normal reflected echoes without scratches have complicated shapes, making it difficult to detect scratch echoes. It is extremely difficult to do and requires a high degree of skill. Furthermore, subtle changes in the contact between the probe and the axle also affect the reflected echo.

Conventionally, level calibration of inspection data was performed by observing the bottom echoes using a calibrator called a standard test piece, and adjusting the sensitivity of the flaw detection equipment so that the bottom echoes at some number were at a constant level. . However, with the sensitivity calibration method described above, it is not possible to calibrate changes in the echo waveform due to subtle changes in the contact state between the probe and the end face of the axle when actually inspecting the axle. When setting the actual axle echo waveform level to an appropriate value, the operator should refer to past axle echo tube waveform photographs or sketches.
The level of the axle echo was adjusted by visual measurement by changing the contact between the probe and the axle. Therefore, the appearance of the echo varies greatly depending on the skill of the operator, making it difficult to obtain a stable waveform.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide an ultrasonic axle flaw detection device that can easily adjust the relationship between the axle and the probe to accurately detect flaws.

Composition of the Invention To achieve the above object, the present invention supplies ultrasonic pulses to the axle using a probe that is used for both transmitting and receiving waves or is separated into transmitting and receiving waves. a transmitting and receiving circuit for obtaining corresponding received waves; an analog-to-digital converter for sequentially converting the received waves into digitized test data; and a transmitting and receiving circuit for sequentially converting the received waves into digitized test data; a digital-to-analog converter for converting the inspection data sequentially read from the memory into an analog signal; a display device for displaying the analog signal in order to detect flaws on the axle; a data extraction circuit for extracting inspection data of a region between a first distance d ₁ and _a second distance d ₂ from one end of _the memory; first reference data corresponding to a first height _h1 that is lower than the height of the reference echo obtained corresponding to the area between
a first memory circuit storing D ₁ ;
and storing second reference data _D2 corresponding to a second height _h2 higher than the height of the reference echo obtained corresponding to the area between the distance _d1 and the second distance _d2. The average value D _A of the test data extracted by the second storage circuit and the data extraction circuit is calculated, and the average value D _A and the first and second storage circuits obtained from the first and second storage circuits are calculated. Second reference data D ₁ , D ₂
and when the average value D _A is between the first reference data D ₁ and the second reference data D ₂ , the probe is in proper contact with the axle. The present invention relates to an ultrasonic axle shaft flaw detection device characterized by comprising: an arithmetic and comparison circuit that generates an output indicating that

Effects According to the above invention, the first distance d ₁ and the second distance
_The inspection data of the area _between d _{2 and}
The first reference data D ₁ and the second height h ₂ corresponding to
Since it is determined whether or not it is between the second reference data _D2 corresponding to can.

Embodiment Next, an ultrasonic axle shaft flaw detection apparatus and a flaw detection method according to an embodiment of the present invention will be described with reference to FIGS. 2 and 3. However, since the parts indicated by reference numerals 1 to 14 in FIG. 2 are substantially the same as those shown by the same reference numerals in FIG. 1, their explanation will be omitted.

The ultrasonic axle flaw detection device shown in Figure 2 has a new feature:
It includes an arithmetic circuit 15 for determining the level of a received wave (input signal) and a display 16 for displaying the determination result. The arithmetic circuit 15 includes a data extraction circuit 17 that extracts inspection data corresponding to a range between a first distance d ₁ and a second distance d ₂ from one end of the axle 14; an average value calculation circuit 18 that calculates the average value of the data;
The first reference data corresponding to the first height _h1 of the received wave in the range of _d1 to _d2 is stored in advance.
a second storage circuit 20 that stores in advance second reference data corresponding to the second height _h2 of the received wave in the range of _d1 to _d2 , and an average value. The test data average value obtained from the arithmetic circuit 18 and the first
a first comparison circuit 21 that compares the test data average value with reference data of the first reference data, and sends out a high-level comparison output when the average value of the test data is larger than the first reference data, and sends out a low-level comparison output when it is smaller; A second device that compares the average value of the test data with the second reference data, and outputs a high-level comparison output when the average value of the test data is larger than the second reference data, and generates a low-level comparison output when the average value of the test data is smaller than the second reference data. The comparison circuits 22 and 2
and an inhibit AND circuit 23 that generates an inhibit AND output of two comparison circuits 21 and 22.

The arithmetic circuit 15 and the arithmetic method will be explained in more detail with reference to FIG. Since various parts are generally attached to the axle 14 of a vehicle and it has a complicated shape, various echoes appear even with a normal axle. Therefore, a normal echo that appears at a distance d from one end d ₀ of a normal axle to be inspected or a standard axle is defined as a reference echo, and the pulse W of the above-mentioned reference echo when the probe 2 is brought into contact with the axle 14 in an optimal state
Measure in advance the height h _of h
Let +Δh/2=h ₂ be the second reference height. Then, first reference data D ₁ corresponding to the first reference height h ₁ is written in the first storage circuit 19 in advance, and second reference data D ₂ corresponding to the second reference height h ₂ is written in advance.
is written in the second memory circuit 20 in advance. Further, the allowable width △d of the distance d is determined, d-△d/2= _d1 is set as the first distance, d+△d/2= _d2 is set as the second distance, and the data extraction circuit 17 It is set in advance to extract only the test data in the section from _d1 to _d2 . That is, it is set so that only the test data of the addresses corresponding to d ₁ to _{d 2} of the memory 5 are extracted.

When inspecting the axle 14 to be inspected, the axle 14
The probe 2 is applied to generate an ultrasonic pulse, the received wave at this time is A/D converted and written into the memory 5, and then sequentially read out from the memory 5.
Display on CRT 11 after D/A conversion. As a result, a waveform as shown in FIG. 3 is displayed on the screen of the CRT 11. However, unless the operator is skilled, it is extremely difficult to determine the contact state of the probe 2 from this waveform. However, since this method includes the arithmetic circuit 15 and the display 16, the contact state can be easily confirmed.

Of the data read out from _the memory 5 in _FIG . Next, this extracted data is sent to the average value calculation circuit 18, where the average value D _A of the inspection data of d ₁ to _{d 2} is determined. That is, the average value D _A is obtained by adding the data at the sampling times d ₁ to _{d 2} and dividing this by the number of samples. The average value D _A is calculated by the first and second comparison circuits 21,
22, and the first comparison circuit 21 outputs the height
The first reference data D ₁ corresponding to the height h ₁ and the average value D _A are digitally compared, and in the second comparison circuit 22, the second reference data D ₂ corresponding to the height h ₂ and the average value D _A are compared.
are compared digitally. Both comparison outputs are then sent to the inhibit AND circuit 23.

Now, if the height h of the specific pulse W of the measurement received wave does not reach _h1 , the average value D _A is smaller than the first reference data _D1 and the second reference data _D2 , so
The outputs of the first and second comparator circuits 21 and 22 are both at low level, so the inhibit
The output of the AND circuit 23 also becomes low level, and the display element of the display 16 turns off, indicating that the probe 2 is in an inappropriate contact state.

On the other hand, the height h of the specific pulse W of the measurement received wave is h ₁
~ h ₂ , the average value D _A is equal to or higher than the first reference data D 1 , so the output of the first comparison circuit 21 becomes high level, and the average value D _A becomes the second reference data D ₁ or higher.
Since the reference data D ₂ is smaller than the reference data D 2 , the output of the second comparison circuit 22 becomes a low level. Therefore, the output of the inhibit AND circuit 23 becomes high level,
The display element of the display 16 lights up, indicating that the probe 2 is in a proper contact state.

Furthermore, when the height h becomes h ₂ or more, the average value D _A becomes more than the first and second reference data D ₁ , D ₂ , so that the first and second comparison circuits 21 and 22 The outputs of both become high level, inhibit AND
The output of the circuit 23 becomes a low level and the display element of the display 16 turns off, indicating that the probe 2 is in an inappropriate contact state.

If the display indicates that the contact state of probe 2 is appropriate in the above measurement, continue to display the CRT.
11 waveforms are used for flaw detection. On the other hand, if the display indicates that the contact state is inappropriate, the contact state of the probe 2 is adjusted, and flaw detection is performed when the display state that the contact state is appropriate is reached. In addition, when carrying out a plurality of measurements, the contact state may be confirmed for each measurement or may be carried out intermittently.

As is clear from the above, according to this example,
It becomes possible to know on the display 16 whether the width and level of a specific echo pulse when checking the contact state of the probe 2 is within a predetermined width and level, and the contact state of the probe 2 can be checked. It becomes possible to immediately judge the quality. Therefore, even a person who is not skilled in the work can easily set an appropriate contact state and perform accurate flaw detection.

Modifications Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and includes, for example, the following modifications.

(1) As shown in FIG.
and a third display element 16a, 16b, 16c, and the same two comparison circuits 2 as in FIG.
2, 21 and each display element 16a to 16c
NOR circuit 23a, inhibit AND circuit 23
b, an AND circuit 23c is provided, and when the average value D _A obtained from the average value calculation circuit 18 of FIG. 2 is smaller than the first and second reference data D ₁ and D ₂ , the first display element 16a lit, average value
When D _A is between D ₁ and D ₂ , the second display element 16
b is lit, and when the average value D _A is larger than both D ₁ and D ₂ , the third display element 16 c may be lit.

(2) The arithmetic circuit 15 may be composed of a microprocessor that executes arithmetic operations according to a predetermined program.

(3) Instead of digitally processing and displaying signals in the digital storage circuits 19, 20 and the digital comparison circuits 21, 22, a digital-to-analog converter is provided after the average value calculation circuit 18, and the storage circuit 19, 20 and the comparison circuits 21 and 22 may be analog circuits, the quality of the contact state of the probe 2 may be determined in an analog manner, and the result may be displayed on the display 16.

(4) Rather than limiting the number of reference echo pulses to one, use multiple reference echo pulses at different distances, and compare the multiple reference echo pulses and the corresponding inspection data individually or by averaging them. Probe 2
The contact state may be determined.

(5) Measurements may be made multiple times under the same conditions, the average value of the multiple measurements may be determined, and this may be compared with reference data.

(6) The operation of displaying the measured waveform on the CRT 11 and the operation of determining the contact state of the probe 2 may be performed independently. When operating independently, a specific address of the memory 5, that is, a distance d ₁ ~
The extraction circuit 17 may be omitted by extracting test data in the d ₁ to _{d 2} interval by reading only the data at the address corresponding to the d ₂ interval.

(7) The reference data written in advance in the memory circuits 19 and 20 may be used as initial measurement data of the axle to be inspected, and the reference data may be used when examining changes over time of the axle to be inspected.

(8) The display 16 may be used as an alarm such as a buzzer.

(9) The probe 2 may be brought into contact with the axle 14 via a spacer.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional ultrasonic axle flaw detection device, FIG. 2 is a block diagram showing an ultrasonic axle flaw detection device according to an embodiment of the present invention, and FIG. 3 is a block diagram showing the device shown in FIGS. 1 and 2. FIG. 4 is a waveform diagram showing the waveforms on the CRT in FIG. 4. FIG. 4 is a block diagram showing a modification of the arithmetic circuit and display. 1... Transmission circuit, 2... Probe, 3... Receiving circuit, 4... A/D converter, 5... Memory, 6...
D/A converter, 7...amplifier, 11...CRT,
14...Axle, 15...Arithmetic circuit, 16...Display device, 17... _d1 - _d2 data extraction circuit, 18...Average value calculation circuit, 19, 20...Memory circuit, 21,
22... Comparison circuit, 23... Inhibit AND
circuit.

Claims (1)

[Claims] 1. Transmission that supplies ultrasonic pulses to the axle using a probe that is used for both transmitting and receiving waves or is separated into transmitting and receiving waves, and obtains received waves corresponding to the ultrasonic pulses. and a receiving circuit; an analog-to-digital converter that sequentially converts the received waves into digitized test data; a memory into which the test data obtained from the analog-to-digital converter is sequentially written; a digital-to-analog converter that converts the sequentially read inspection data into an analog signal; a display device that displays the analog signal to detect flaws on the axle; and a first distance from one end of the axle. d ₁ and the second distance
a data extraction circuit for extracting inspection data of a region between the first distance d2 and the second distance d2 from the memory; and a _data extraction circuit for extracting inspection data of a region between the first distance _d1 and the second distance _d2 ; First reference data corresponding to the first height h ₁ lower than the height
a first storage circuit storing D ₁ ; and a second storage circuit that is higher than the height of the reference echo obtained corresponding to the area between the first distance d ₁ and the second distance d ₂ . A second storage circuit stores second reference data D ₂ corresponding to the height _{h 2 of} The first and second reference data D 1 and D 2 obtained from the first and second storage circuits are compared, and the average value D _A is equal to the first reference data D ₁ and the second reference data D ₁ , D ₂ . standard data of
an arithmetic and comparison circuit that generates an output indicating that the probe is in proper contact with the axle when the probe is between _D2 and D2; Device.