SU404008A1 - ULTRASONIC DEFECTOR - Google Patents

Description

one

The invention relates to non-destructive tools and methods of control and can be used in ultrasonic flaw detection of coarse-grained materials.

A known ultrasonic flaw detector containing a sequentially connected synchronizer, signal generator, searchers, amplifier, defect detection unit, indicator and transducer is a time interval-code whose inputs are connected to the synchronizer and to the output of the amplifier.

This flaw detector allows the determination of a defective condition based on a direct estimate of the time it takes the oscillations to pass through the product. At the same time, the reliability of automatic detection of defects is low due to the influence on the propagation time of oscillations of the structural and strength characteristics of the material of the product.

The aim of the invention is to increase the reliability of automatic control by fixing the rate of change of the time of oscillation through the product during the scanning process.

For THIS, the defect detection unit is made in the form of an analyzer, the adder and the transducer are a time interval code, the zero and single unit outputs of the cells through valves are connected to informational inputs of the adder. The output of the latter is connected to the information input of the analyzer. The control inputs of the adder, analyzer and valves are connected to the output of the amplifier through series-connected delay elements.

The drawing shows the block diagram of the proposed flaw detector.

It contains a synchronizer 1, to the output of which the probe generator is connected

pulses 2; radiating 3 and receiving 4 searchers; an amplifier 5 connected to a receiving searcher by an input to a defect detection unit consisting of a “time interval code 6” transducer whose zero outputs and single outputs of the cells are connected to the inputs of the adder, respectively; the analyzer, the input connected to the output of the adder, and the output associated with the indicator;

series-connected delay elements 9-12, the outputs of which are connected to the control inputs of the valve groups 7 and 8, the adder and the analyzer, respectively. In addition to the second, the second input of the output block

the defect is connected to the synchronizer through the delay element 13.

The scheme operates as follows. The probe generator generator 2, triggered by synchronizer 1, excites the searcher 3. The ultrasonic oscillations emitted by the searcher 3 pass through the article, 1 of them and arrive at the receiving searcher 4.

The signal from the receiving searcher, after amplification and normalization in amplifier 5, is fed to a defect detection unit, to the second input of which a pulse comes from synchronizer 1. The synchronization signal through delay element 13 is fed to the converter "time interval-code 6" and starts it.

The conversion cycle ends when the signal converter from amplifier 5 arrives at the second input. At the same time, the digital equivalent of the time of oscillation through the product is recorded on the converter counter. Through the valve group 7, the additional code of digital equivalent from the bullet outputs of the counter cells of converter 6 enters cyiviMaTop 14, where algebraic sum of the code received from the converter with digital equivalent of the time of ultrasonic vibrations passing through the product at the previous package is carried out. The result of the addition (difference) enters the analyzer 15, which analyzes the sign and the magnitude of the difference between the codes. Depending on the sign of the difference, the value of the direct or inverse result code is analyzed.

When the result of the set limit is exceeded, a pulse appears at the output of the analyzer, indicating the presence of a defect in the product and arriving at indicator 16. Then, the adder 14 is reset to zero and the direct code from the unit outputs of the counter cells of the converter 6 is reset through a group of valves 12.

This code will be added to the duplicate code of the digital equivalent of the transit time of the ultrasonic vibrations on subsequent sending.

Commands for transmitting additional code to the adder, analyzing the result, resetting the sum of a VI lock and sending the direct code to the adder are formed from the signal from the amplifier output by successively connected delay elements 9-12.

The delay element 13 delays the start of the transducer "time interval-CODE 6 by the value 4ad., Which is less than the minimum possible transit time of ultrasonic oscillations

through the product msh- In this case, the digital equivalent of the time t proho is fixed in the converter 6 ../

where / proh. - time of passage of oscillations through the product.

This makes it possible to significantly reduce the size of the converter 6 and the adder 14 without reducing the accuracy and sensitivity of the flaw detector.

Subject invention

An ultrasonic flaw detector containing a series-connected synchronizer, signal generator, searchers, amplifier, indicator and defect detection unit, whose inputs are connected to the synchronizer and to the amplifier output, characterized in that, in order to increase the reliability of the automatic control, the defect detection unit is released in the form of an analyzer, adder and converter, a "time interval code," "zero and" single outputs of the cells of which, via valves, are connected to the information inputs of the adder, the output of which is connected to information input of the analyzer, and the control inputs of the adder, analyzer

and valves are connected to the output of the amplifier through successively connected delay elements.