SU888028A1 - Ultrasonic echo-pulse flaw detector - Google Patents

Description

(54) ULTRASONIC ECHO-PULSE DEFECTOSCOPE

one

The invention relates to non-destructive testing methods of materials and can be used in the development of devices for automatic ultrasonic (US) control of products and materials.

Known ultrasonic echo-pulse flaw detector containing an amplifier and a synchronizer connected to the input of the control channel, which includes a delayed unit connected in series, a gate driver and an amplitude-time selector 1.

By a known flaw detector, only a certain constant thickness of the product can be monitored, since the control zone is determined by the fixed duration of the gating pulse.

The disadvantage of the known flaw detector is the inadequate reliability of the control, since it is impossible to control the bottom defects in products with a complex bottom shape.

The closest to the invention in technical essence and the achieved result is an ultrasonic echo pulse pulse detector containing a series-connected synchronizer.

the first delay unit, the first strobe pulse shaper, the first selector and the OR circuit, the amplifier whose output is connected to the second input of the first selector, and the second delay unit 2.

The disadvantage of the known flaw detector is the low reliability of the control, since it is impossible to check the bottom defects in products with a complex bottom shape.

The purpose of the invention is to increase the reliability of the control.

ten

The goal is achieved by the fact that the ultrasonic flaw detector is provided with a third delay unit connected in series, the input of which is connected

Claims (2)

5 to the synchronizer output, the second strobe pulse shaper, the second input of which is connected to the output of the OR circuit, and the second selector, the second input of which is connected to the output of the second delay unit, and a differentiating unit connected between the first strobe pulse shaper and the OR circuit, and The input of the second delay unit is connected to the output of the amplifier. FIG. one . a structural diagram of the proposed ultrasonic flaw detector is presented; in fig. 2 - detrimental diagrams that show the work of the scheme. The ultrasonic flaw detector contains a synchronizer 1 connected in series, a first delay unit 2, a first strobe pulse shaper 3, a first selector 4 and an OR 5 circuit, an amplifier 6 whose output is connected to the second input of the first selector 4, a second delay block 7 whose input is connected to the output of the amplifier 6, connected in series to the third block 8 of the delay, the input of which is connected to the output of the synchronizer 1, the second driver 9 strobe pulses, the second input of which is connected to the output of the circuit OR 5, and the second selector 10, the second input D which is connected to the output of the second delay unit 7, and the differentiating unit 11 connected between the first pulse shaper 3 and the OR circuit 5. The ultrasonic flaw detector works as follows. Pulse 12 (see Fig. 2) comes from the output of the synchronizer 1 to the delay blocks 2 and 8. From the output of blocks 2 and 8 of the delay pulses start the shapers 3 and 9 strobe pulses. The pulse delay from the synchronizer 1 output and the strobe duration of the bottom control zone must be such that the strobe of this channel covers the entire zone of possible variation of the locations of the pulses reflected from the bottom of the product. This strobe pulse is fed to the selector 4 and transmits the video signal 13 amplified by amplifier 6, reflected from the bottom of the product, which is fed to one of the inputs of the circuit OR 5. The triggering level of the threshold elements of the selector 4 is higher in the bottom control zone than in the control zone defect. The second input of the OR circuit 5 through the differentiating unit 11 from the output of the strobe pulse shaper 3 is supplied with the falling edge of the strobe pulses 14. The strobe pulse shaper of the defect control zone is triggered through the delay block 8 in order to get away from the dead zone. The strobe pulse zone of the defect control zone is reset by pulses 15 from the output of the circuit OR 5. Strobe pulse 16 determines the defect control zone and passes the video signal from amplifier 6 delayed by block 7 to the selector 10, which is recorded as a defect when a certain level is exceeded. Consequently, in the OR 5 circuit, a logical addition of this signal with a pulse delayed relative to the time position of the bottom signal occurs. If the sensitivity of the threshold element of the selector 4 of the control area of the bottom of the product is set lower than the sensitivity of the threshold element of the selector 10 of the defect control area (as is usually set on automatic defect signaling devices), then the strobe-pulse of the defect control area in the presence of bottom reflection is interrupted from the bottom of the product, and the defect is clearly recorded. If there is little or no reflection from the bottom of the product, i.e. below the threshold element level of the bottom control zone (for example, due to a hole in the bottom, bottom surface roughness, a large defect, etc.), the strobe pulse zone defect monitoring is disrupted by a pulse delayed relative to the time position of the bottom signal, and product quality information is not lost. If, for any reason, the bottom signal disappears or its certain level decreases, the trailing edge of the strobe zone of the control zone is determined by a pulse delayed relative to the bottom signal, thereby increasing the reliability of the control. Thus, it is possible to control products with a complex bottom shape and limit the control zone immediately after the expected arrival time of the signal reflected from the bottom of the product, which increases the reliability and noise immunity and, therefore, the quality of information obtained during ultrasound monitoring. An ultrasonic pulse-echo flaw detector comprising a synchronizer connected in series, a first delay unit, a first strobe pulse generator, a first selector and an OR circuit, an amplifier whose output is connected to a second input of the first selector, and a second delay unit, characterized in that in order to increase the reliability of the control, it is equipped with a third delayed unit connected in series, the input of which is connected to the synchronizer output, the second strobe pulse former, the second input cat cerned is connected to the output of the OR circuit and a second selector, the second input of which is connected to the output of the second delay unit, and a differentiating unit connected between a first strobe pulse generator and the OR circuit and the second delay block input connected to the output amplifier. Sources of information taken into account in the examination of 1- Technical description of the device UD-10UA. Chisinau, “Electrical Appliance, 1972. 2. USSR author's certificate No. 534690, cl. G 01 N 29/04, 1975 (prototype). 12 13 / " FIG. one I