JPS58129358A - Ultrsonic flaw detector - Google Patents

Abstract

PURPOSE:To detect the position of flaw at a high accuracy by statistic processing of a reflected echo train with a computer after it is sampled being shifted by unit time with a sampling circuit. CONSTITUTION:A high frequency sine wave outputted from a frequency totalizer 6 is divided down to a desired frequency with a frequency divider circuit 7, an output of which drives a pulse generation circuit 9 as gate signal to apply a high voltage pulse to a transducer 10. Echos reflected from flaw in an object to be inspected are converted into electrical signal again with the transducer 10 and inputted into a sampling circuit 13 passing through an amplifier 12. A sampling trigger pulse is applied to the sampling circuit from a delay circuit 8 being shifted by a unit time starting from the pulse delayed by a delay time set with a computer 15 with the rising of a transmission pulse as reference. A sampling output is inputted into the computer 15 after an A/D conversion for statistic processing and the position of flaw is displayed as image on a CRT.

Description

[Detailed description of the invention] The present invention relates to an ultrasonic flaw detection device.

Ultrasonic flaw detection equipment has recently been rapidly put into practical use as a non-destructive testing device using ultrasonic waves.

The difference in principle is the transmission method, impulse reflection method,
Classification into three types of resonance methods - gr.

The transmission method is a method in which ultrasonic waves are applied from one side of the object to be inspected, and the presence or absence of flaws in the middle is estimated based on the intensity of the sound waves scattered on the other end of the object, and is relatively easy to use. K, which obtains information such as the location of scratches, lacks accuracy.

Next, the resonance method is a measurement method commonly referred to as an ultrasonic thickness meter, and is not suitable for detecting flaws in an object to be inspected.

The last impulse reflection method is the same basic principle used in this ultrasonic flaw detection device.

In other words, the conventional impulse reflection method, in which the presence or absence of scratches at the 0 position is measured by injecting an ultrasonic impulse from one surface of the object to be inspected and observing the reflected waves from other surfaces and intermediate scratches, does not require the observation of reflected waves. This had to be carried out on a cathode ray tube such as an Oshida scope, and the reflection time was read from the time axis memory on the cathode ray tube.

This method allows for highly accurate distance IIl measurement and sharply deformed Ii! column was impossible.

Recently, there has been a strong demand for ultrasonic flaw detection to accurately determine the location and shape of flaws inside objects to be inspected, and we are eagerly awaiting the emergence of new automated ultrasonic flaw detection equipment. was.

The present invention was devised in order to eliminate the drawbacks such as low precision and unclear images associated with the conventional ultrasonic flaw detection equipment as described above.
The object of the present invention is to provide an ultrasonic flaw detection device that can accurately measure the position of flaws and fix the shape side by accurately measuring the peak position of the reflected echo and the beater voltage tube.

The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram of a conventional ultrasonic flaw detection device using the impulse reflection method.

This block diagram shows a method called the Muscope method, which is a simple method among impulse reflection methods, and transmits a pulse of -6 and a scratch pulse -k on an oscilloscope.

The bottom pulse-C is measured at [l1111].

[1] is a block diagram of the present ultrasonic flaw detection device.

The main features of this device are a CK instead of the oscilloscope 5 for pulse observation shown in Figure 1, a delay path 8, a throttle circuit 13, a MU/D converter am-14, a computer 15, and a monitor oscilloscope. -16 is used.

In other words, this device and the Mus;-pu method shown in Fig. 1 are as follows:
The basic parts are the same as shown below.

First, the frequency synthesizer 6 corresponds to the synchronizing section 1 in FIG. 1, and the minute m1iii path 7 and the high voltage pulse generating circuit 9 correspond to the transmitting section 2.

Similarly, the receiving section 3 of l1llil corresponds to the wideband amplification path 12 of this device.

Basically, this device follows the same principle as the impulse reflection method, that is, a pulse is made incident on the object to be inspected, and the echoes reflected from the scratches are determined to obtain information 1 on the internal structure of the object to be inspected. Therefore, the synchronization section, transmission section 1, and reception section S for obtaining a basic reflected echo all have the same configuration.

This device is an effective system for processing the reflective nib and obtaining useful information on its internal structure obtained from this basic part.

First, we will explain the basic steps for obtaining reflected echoes using this device.

The high-frequency sine wave output from the frequency synthesizer 6 is divided into the desired frequency by the frequency divider circuit 71, and then the desired frequency of the division signal is reached (rise of the desired tie) for an arbitrarily set time. A pulse of width is output.

This output is used as a gauge signal and gated to the sine wave tube output from the local wave total circuit 6, and further amplified to hundreds to thousands of volts to form the so-called R1 pulse t, and this rt to the transgenie? Add -1 to -10.

The transducer 10 mechanically vibrates in response to the imprinted high-voltage pulses and injects an ultrasonic wave into the object to be inspected.

The ultrasonic waves are reflected by a silver sound wave reflector such as a scratch while the object to be inspected undergoes internal erosion, causing the transgener Lot to vibrate again.

The transducer is a wideband amplifier a that outputs the vibration (by mechanical → electrical conversion) as an electric signal to the wideband amplifier 12.
In m, the jolt ego train is attenuated by an appropriate amplification factor, and after correction, only the envelope line on the positive potential side of the reflector 1-row is detected and output.The rL nine reflections obtained from the above basic part are Explanation of the main parts of this device, which processes the echo train efficiently in the next X step and thereby obtains information about scratches with high precision, will be explained next.

Processing of the train of reflected echoes output from the broadband amplifier begins with a sampling path.

The sampling timing is shown in Figures 3 and 4.
In FIG. 3, 17 is a transmission pulse and has a propagation time τs
*A reflected echo 18 from the wound appears* t f
t) 19 @ is the il1th reflected echo from the bottom surface, and similarly, t96 is the II2nd I reflected echo from the scratch.

FIG. 4 is an enlarged view of the transmitted pulse 17 and the reflected echo 18 from the wound in FIG. 3.

r a #ix Delay circuit-8 is a controller with the rising edge 9 of the transmission pulse as a reference, and the setting name is the ultimate delay time, and the delay circuit is a pulse t sampling that is delayed by τG and p delayed than the transmission pulse. Output to the circuit.

The computer determines the desired delay time τat as the output point,
τ, the trigger pulse for sampling is shifted by unit time [operates to be output from the delay circuit].

Sweeping at the time of delay stops when the printer fs times have been completed.

During this period, the output of the sampling every - time is converted into a digital signal by the M/D conversion time @1% -14, and is input to the combiator.

The combiator stores the data of gkwA, then detects the maximum value, calculates the delay time when reaching the maximum value of 1,
Perform statistical geography to remove data noise.

The information obtained at the end of the meeting is output to an oscilloscope or OR desk, etc., and the internal structure is immediately made known to humans through numerical values, IM meetings, etc.

Computer day! Collection and maximum value detection, determining the delay time at the maximum value 7El-Char) t@i6.

As mentioned above, the single ultra-wave flaw detection device uses an echo train sampling method using a sample circuit to avoid the lack of accuracy and noise caused by conventional FCT flaw detection.
By performing M/D conversion and statistical processing, it has become possible to have high-precision position detection 0 self-reproduction ability.

The company considers this device to be an extremely economical and useful device that is effective for data communication and can be used 1ly INfK.

[Brief explanation of the drawing]

FIG. 1 shows a boot diagram of the conventional impulse reflection method, and FIG. 2 is a block diagram of the present invention.
The figure is an enlarged view of the reflected echo array and a portion thereof. FIG. 5 is a sectional view of the object to be inspected. Figure 6 shows a 7-chart diagram of computer processing. 11. Synchronization section 29. Transmission unit 31. Receiving section 40. Inspected object 51. Oscilloscope 6,, Ii wave number synthesis, 700 minutes w4 circuit 80. Delay circuit 90. High voltage pulse generation circuit 1G, , ) Lancer 116. Inspected object 120. Broadband increase S* 13, #Sumbrinda ia* 141. Mu/p quality exchange country road 150. Computer 1 160. Oscilloscope or OR 17-211. Echo train no., object to be inspected no., scratch etc. Fig. 1 3 Fig. 2 Fig. 3 [21 Fig. 5 Fig. 6

Claims (1)

[Claims] A frequency integrated circuit that generates a 1% frequency value wave, a frequency divider circuit that divides a high frequency sine wave, and a delay path that delays the output signal of the divider circuit over a desired range. , and a high-voltage pulse generation circuit that inputs the high-frequency sine wave generated from the frequency integrated circuit and amplifies it to a high-voltage signal while gated by the output signal of the frequency dividing circuit, and a lance generator that converts the electric signal into an ultrasonic wave. , and a broadband amplification circuit that amplifies the sample to be measured and the reflected echo and detects its envelope, and the IJ output by the delay circuit,
The fl pulse causes a sampling circuit to sample and store the echo, and a sampling voltage to the digital IN.
In an ultrasonic flaw detection device emitted from a computer that controls a MU/D conversion circuit, an oscilloscope, and 70 tubes, the computer sets the delay time of the delay circuit to τ & fi at intervals of τO from a desired value a. The delayed signal is then sampled in the sampling circuit, converted to MU/D, and stored, and then the entire data is
By searching for the large voltage above the t comparison and outputting the delay time corresponding to the wrinkle voltage value, it is possible to measure the ultrasonic propagation relationship to the flaw in the sample with high precision, and also to detect the peak of the echo. Ultrasonic flaw detection equipment that measures t% mold along with the height.