JPS5942696Y2 - Ultrasonic flaw detection equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic flaw detection device that nondestructively inspects a material to be inspected by ultrasonic angle flaw detection.

Normally, when this type of flaw detection equipment measures the gap position of the material to be inspected, the beam path from the cathode ray tube screen of the A-1 base ultrasonic flaw detector to the defect read is determined by the sine of the refraction angle of the ultrasonic beam. By multiplying by the cosine, the distance between the probe and the defect and the depth of the defect are calculated.

However, the above-mentioned measurement needs to be performed every time a defect is detected, and complicated calculations are required each time, making the measurement work extremely complicated.

The present invention has been devised in view of the above points, and an object of the present invention is to provide an ultrasonic flaw detection device that has a simple configuration and is capable of accurately displaying defect positions at all times.

In order to achieve the above object, the present invention provides an ultrasonic flaw detection device that non-destructively inspects materials by ultrasonic angle flaw detection. an oscillator, and a second oscillator that oscillates at a frequency equal to the above frequency multiplied by the sine of the refraction angle θ of the ultrasound beam.
a variable frequency oscillator, a third 9 variable frequency oscillator that oscillates at a frequency obtained by multiplying the frequency by the cosine of the refraction angle θ, and a measurement gate signal with a pulse width depending on the defect position based on the clock signal and the echo signal. A timing circuit that generates the signal, a gate group that uses the measurement gate signal of this timing circuit as a control signal, and a gate group that inputs the output of each variable frequency oscillator, and counts the output of each gate in this gate group, and calculates the beam path and probe. The present invention is characterized in that it is equipped with a count display section that digitally displays the distance between the defect and the defect and the depth of the defect.

The present invention will be explained in detail below based on the illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, in which 1 is the main body of the ultrasonic detector, 2 is a trigger (clock) signal from the main body 1, a measurement gate signal F1 inhibit pulse upon receiving an echo A,
Zero point adjustment pulse, set pulse, timing circuit to obtain reset pulse, 3 is the required pulse width, e.g. 200μ
Pulse generation ia4, 5.6 that generates the gate pulse of B
The d variable frequency oscillation 4 oscillates at a frequency of 7f that generates one pulse for the one-way distance traveled by the oscillation js4d ultrasonic beam, that is, the beam path length of 1 m++.

Source 1 JiRiG5 is the refraction angle θ of the frequency fK ultrasound beam.
The oscillator 6 oscillates at a frequency multiplied by the sine of , that is, sin θ, and the oscillator 6 oscillates at a frequency f cos θ.

Reference numeral 1 denotes a frequency divider for frequency-dividing the output of the variable frequency resonator 4, and its frequency division ratio is set to, for example, 1/1000Vc.

8,9. It) is an AND gate, and AND gate 8
is the output of the variable frequency oscillator 4, Antogate) 9 is the output of the oscillator 5, Antogate)1dK is the output of the oscillator 6, and each AND gate 8, 9 . A measurement gate signal F, which is the output of the timing circuit 2, is applied to ILI via a display changeover switch 21.

In other words, switching contact 11-1 connected to Antogame) dK
The timing circuit 2 is connected to one side, and the pulse generator 3 is connected to the other side.

The timing circuit 1 is connected to one of the switching contacts 21-i and zs-a connected to the AND gates 9 and 10rc, and the frequency dividing circuit 61 is connected to the other fc.

11, 12, and 13 are frequency dividers whose division ratio f is set to, for example, 1/100.

14ri a display section that receives the output of the counter 15 that counts the output of the frequency divider 411 and displays the ultrasonic beam path or the sound velocity of the material to be inspected; 16 receives the output of the counter 11 that counts the output of the divider 12; 1d is a display unit that displays the defect depth or ric o sθ in response to the output of the counter 19 that counts the output of the branching unit 13; The counter 1 is a preset circuit using a digital switch used when measuring VC using the double reflection method.
Generates 9 preset inputs.

Next, the measurement operation of the above device will be explained with reference to FIGS. 2 and 3.

First, the measurement display operation by the direct method will be explained with reference to FIG.

The ultrasonic probe 1a is attached to the material to be inspected AOK.

It is assumed that a defect mAJa exists inside the inspected material 30, and the distance between the probe and the defect is Y1, the beam path length is W1, the defect depth is 01, and the refraction angle of the ultrasonic beam is θ.

When ultrasonic waves are emitted from the probe 8'k''f-1a to the material to be inspected 30, an echo A is received.

This echo AK includes a transmitted pulse echo and a defective echo.

The timing circuit 2 generates an inhibit pulse, a set pulse to the zero point adjustment pulse, and a reset pulse based on the echo A1 clock signal Y and the threshold value, which form a measurement gate signal F having the required pulse width.

The distance between the probe and the defect is measured and displayed from this measurement gate signal, but adjustment is required before doing so.

At the time of adjustment, the selector switch 11 is switched to the adjustment side (the dotted line side in the figure).

In this state, the pulse from the pulse generator 30,200 μs becomes the gate control signal for the AND gate 8, and
The output of 44 is gated with a 200 μS pulse, counted by a counter 15, and displayed on the display section 14.

At this time, for example, the sound velocity of the material to be inspected 3σ is 3250 m/
s, the oscillation frequency of the variable frequency oscillation 44 is adjusted so that the display $14 becomes M2.

Assuming that this oscillation frequency is f, a signal obtained by dividing the frequency by 1/1ooovc is generated at W7, which becomes the gate control signal for the AND gates s and io.

As a result, the output pulses of the oscillators 5 and 6 are controlled, counted by the counters 17 and 19, and displayed on the display section 16.18.

This display is sinθ. Adjust the oscillation frequency of oscillator 5.6 to be equal to 1000 times e08 θ.

After adjustment, changeover switch 21t - measurement 11 (solid line position)
When switching K, each AND gate 8. A measurement gate signal F is added as a gate control signal of d and 10.

The frequency-adjusted output of the 44°5.6 oscillation corresponding to each gate 8, 9, 10d is added as an input, and the pulse train of each AND output is input to the corresponding counter 15, 17, 19.
Each count is digitally displayed as a simple value on the display section 14 as a beam path length W1 display section 16Kd, a probe-to-defect distance Y1 display section 18Vc, and a defect depth D.

That is, the pulse width of the measurement gate signal F changes depending on the position of the defect 30a, which corresponds to the beam path length,
The number of pulses with a frequency proportional to the sound velocity determined by the material 'Rvc of the material to be inspected 30 during this period is displayed as the beam path length.

Similarly, the number of pulses in the pulse width of the measurement gate signal F adjusted to a frequency of sin 0 times and cos 0 times the above frequency is the distance between the probe and the defect, the beam path, and the sin
Based on the proportional relationship between θ, defect depth and beam path length/e08 θ, the distance between the probe and the defect is displayed as the defect depth.

On the other hand, in the case of the -times reflection method, the ultrasonic beam path is once reflected at the bottom surface of the inspected material 30 and reaches the defect 30 arc, as shown in FIG.

In this case, the defect depth D is calculated as D', so the preset value of the counter 19 is set to twice the thickness T of the material to be inspected 30 by the preset circuit 20, and the defect depth by the direct method is When the measured value exceeds the thickness of the material to be inspected, the preset circuit 20 is connected to the measurement system by a changeover switch (not shown) K, and the counter 19 counts down.

As a result, the actual defect depth D is D=2T-D' is required and displayed.

However, the counter 19 needs to be a reversible counter.

In addition, 1o is provided by the branching devices 11, 12, and 13.

The measurement results are averaged to stabilize the display.

Usually, in the timing circuit 1rcsr, the threshold value that is used as a defect discrimination criterion, the zero point corresponding to the incident point of the ultrasonic beam, and the range for removing the influence of the transmitted pulse echo, that is, the pulse width of the inhibit pulse, can be adjusted. be.

The zero point adjustment pulse is used to adjust the time from the start of excitation to the time of incidence on the surface of the material to be inspected, which varies depending on the probe, and has a variable pulse width along with the inhibition pulse.

To obtain a pulse with a variable pulse width, a monostable multivibrator (with a time constant that can be arbitrarily set) may be combined and triggered by a clock signal.

Furthermore, the measurement gate signal F and the inhibition pulse can be sent from the timing circuit 2 to the main body 1 of the flaw detector and displayed on the cathode ray tube screen of the main body 1.

This display makes it clear at a glance the prohibited range and the measurement area of the echo, and is effective for finding the desired reflection point from the echo of an actual complex waveform.

As described above, according to the present invention, the variable frequency oscillator is simply adjusted so that the oscillation frequency is proportional to the sound speed of the material to be inspected, and the frequency is multiplied by the sine and cosine of the refraction angle of the ultrasonic beam. The ultrasonic beam path, distance between the probe and defect, and defect depth can be digitally displayed with just one operation, making measurement extremely simple.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing an embodiment of the ultrasonic flaw detection device according to the present invention, and FIGS. 2 and 3 are operation explanatory diagrams. 1... Flaw detector main body, 1a... Probe,
2...Timing circuit, 3...Pulse generation G, 4-6...Variable frequency oscillator, 7.1
1-13... Frequency divider, 8-10-... AND gate, 14, 16, 18... Display section, 15
, 17, 19... Counter, 20... Preset circuit, 21... Changeover switch.

Claims (1)

[Scope of Claim for Utility Model Registration] ■ In an ultrasonic flaw detection device that inspects a material to be inspected by ultrasonic angle flaw detection, a first variable frequency oscillator that sets the oscillation frequency to a frequency that is relative to the sound speed of the material to be inspected. and a second variable frequency oscillator that oscillates at a frequency obtained by multiplying the above frequency by the sine of the refraction angle θ of the ultrasound beam;
a third variable frequency oscillator that oscillates at a frequency obtained by multiplying the frequency by the cosine of Using the measurement gate signal as a control signal, a gate group inputs the output of each variable frequency oscillator, counts each gate output of this gate group, and digitally calculates the beam path, the distance between the probe and the defect, and the defect depth. An ultrasonic flaw detection device comprising: a count display section for displaying counts; 2. Install a switching stop at the control signal input terminal of the gate group.
Ultrasonic flaw detection according to claim 1, in which the output of the pulse generator that generates pulses and pulses with a predetermined pulse width and the first variable frequency oscillator is used as the gate 71tll# signal during adjustment of the gate group. Device. 3 The defect depth measurement system of the count display section is equipped with a preset circuit that presets a value equivalent to twice the thickness of the material to be inspected, and the counter is a reversible counter, and the defect depth measurement system uses the ultrasonic angle angle flaw detection one-time reflection method. The ultrasonic flaw detection device according to claim 1, which is a utility model registered and is operated as a subtraction counter at 5vC during measurement.