JPH06201662A - Flaw-detection-signal discrimination apparatus - Google Patents

Abstract

PURPOSE:To obtain a flaw-detection-signal discrimination apparatus wherein the judgment level of a flaw signal is lowered without being troubled with a noise and a small harmful flaw is not overlooked. CONSTITUTION:Flaw detectors 3, 4, 5 and a marker 6 are arranged sequentially along the route of a material 1 to be inspected, signals obtained by the individual flaw detectors are delayed respectively by delay units 13, 14, 15, the delay time of the delay units 13, 14, 15 is selected in such a way that the flaw signals which are caused by the same flaw and which are obtained by the individual flaw detectors are output from the individual delay units at the same time, and the marker 6 is controlled on the basis of two or more logical products of outputs from the delay units 13, 14, 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for marking a material to be inspected on the material to be inspected based on the inspection result of a flaw detector.

[0002]

2. Description of the Related Art Conventionally, it has been practiced to inspect a material with a flaw detector and to mark the material on the basis of the inspection result to indicate the position of the flaw. Therefore, a marker is placed after the flaw detector, and the flaw detection signal is delayed by the time required for the inspection material to move from the flaw detection position to the marking position.
This controlled the marker. Even when a plurality of types of flaw detectors are continuously arranged and different inspections are performed, the flaw detectors perform the above-described markings independently of each other.

[0003]

The wave height of the flaw signal detected by the flaw detector is not constant due to the variety of flaw forms, and even flaws that do not reach the judgment level may be harmful, and they are overlooked. Sometimes. To prevent this, it is necessary to improve the surface condition of the material, highly control the position and orientation of the material entering the flaw detector, reduce the noise in the signal as much as possible, and then set the judgment level low. However, it will cost a lot of money and increase the false alarm rate. It is an object of the present invention to obtain a highly reliable flaw detection result without adopting the above-mentioned costly device.

[0004]

In the present invention, a plurality of types of flaw detectors are arranged in order along the path of the material to be inspected, and a marker is placed at the end. Each flaw detector is equipped with a signal delay device that delays the flaw detection signal by the time required for the material to be inspected to reach the marker position. The marker is provided with a logical product of a plurality of delayed outputs of the signal delay devices, on the basis of which the marker is configured to operate. A computer memory can be used as the signal delay device.

[0005]

In the above-mentioned device, the flaw detection signal of each flaw detector of the material to be inspected is adjusted by the delay time of each signal delay device, so that the flaw detection signal of the same portion by each flaw detector is simultaneously output from each signal delay device. It is output, and at that time point, the above portion has reached the marker position. The marker is then activated by the logical product of the outputs of the signal delay devices.

The flaw signal and the pseudo flaw signal obtained from the material to be inspected have different sensitivities depending on the type of flaw detector. In the case of a harmful flaw, a flaw signal of a certain level appears even when flaw detection is performed by any type of flaw detector. Therefore, if the logical product of flaw detection signals obtained by different types of flaw detectors from the same part is obtained as described above, even if the judgment level is lowered, a signal of a slight flaw or a false flaw signal is erroneously determined as a harmful flaw. The risk of being damaged is reduced, and it is possible to reduce the situation of overlooking harmful damage without spending a large amount of money.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a material to be inspected 1 travels on a path 2 and along the path 2 different types of flaw detectors 3, 4 such as an ultrasonic flaw detector, a leakage magnetic flaw detector, an eddy current flaw detector, 5 are arranged in order, and a marker 6 is provided at the subsequent position. Further, transmitters 7, 8 and 9 are provided which are close to the flaw detectors and generate a clock signal having a cycle corresponding to the traveling speed of the material 1 to be inspected.

With respect to the flaw detection signals of the flaw detectors 3, 4, and 5, the portions exceeding the set level are taken out by the wave height determination circuits 10, 11 and 12, respectively, and the shift registers 13 and 14,
The shift registers are driven by clock signals generated by oscillators 7, 8 and 9, respectively. The delay time of each shift register depends on the flaw signal due to the flaw 16 detected by the flaw detectors 3, 4, and 5.
The scratches 13 are selected so as to be output all at once when they reach the position of the marker 6.

The output of the shift register 13 is output to the AND gates 17, 18 and 19, the output of the shift register 14 is output to the AND gates 17, 19 and 20, and the output of the shift register 15 is output to the AND gates 17, 18 and 20, respectively. Given these AND gates 17, 18, 19, 20
The output of is integrated by the OR gate 21 and supplied to the marker 6. At the moment when the signal is given from the OR gate 21, the marker 6 sprays the paint from the nozzle 22 to mark the position of the scratch 16 on the inspected material 1.

In the above apparatus, the AND gate 1
Nos. 7, 18, 19 and 20 refer to each other two or more kinds of the scratch signals obtained by the scratch 16, and two or more kinds of scratch signals simultaneously exceed the judgment level of the wave height judgment circuits 10 to 12. If so, an operation signal is generated and supplied to the marker 6 to perform the marking operation.

Here, if the judgment level in the wave height judgment circuits 10, 11, 12 is lowered, it becomes possible to pick up a scratch signal based on minute harmful scratches, but on the other hand, many pseudo scratch signals are picked up from noise. Will be issued. However, while the flaw signal is detected by a plurality of flaw detectors at the same position, the pseudo flaw signal is irregularly generated.
It can be sieved off with 8, 19, 20. If the type of flaw detector is different, the appearance of flaw signals and noise is also different. Therefore, the determination level in each wave height determination circuit 10, 11, 12 is adjusted individually. Furthermore, when not only a flaw detector but also a dimension inspection machine such as a diameter or a wall thickness is provided, the inspection signal can be processed simultaneously with the flaw detection signal.

[0012]

As described above, according to the present invention,
Even if the judgment level is lowered so that minute harmful scratches can be detected, the pseudo scratch signal based on noise can be removed, so highly reliable flaw detection results can be obtained without incurring a large amount of cost. is there.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 material to be inspected 2 traveling path 3 flaw detector 4 same as above 5 same as above 6 marker 7 clock signal transmitter 8 same as above 9 same as above 13 shift register (signal delay device) 14 above same 15 same as above 17 AND gate (logical AND circuit) 18 same as above 19 same as above 20 Same as above

Claims (1)

[Claims] 1. A plurality of types of flaw detectors and markers arranged in order along the path of the material to be inspected, and a specific portion of the material to be inspected provided for each flaw detector after the particular flaw reaches the flaw detector. A signal delay device that delays the flaw detection signal of the flaw detector for the time required to reach the marker, and a marking that indicates the position of the flaw on the material to be inspected based on the logical product of the outputs of a plurality of signal delay devices. A flaw detection signal discriminating apparatus comprising means for supplying an operation signal for application to the marker.