CS236177B1 - Wiring for automatic aperture adjustment for ultrasonic echoes - Google Patents

Abstract

The purpose of the invention is to automatically adjust the duration of the gate pulse according to the actual thickness of the object. The stated purpose is achieved by an electronic circuit in which a digital accumulator (2) is connected to an ultrasonic thickness gauge (1) by its inputs. The clock input of the digital accumulator (2) is connected via a first delay circuit (3) to the synchronization output of the ultrasonic thickness gauge (1). The outputs of the digital accumulator (2) are connected to the inputs of the down counter preset (4). Its clock input is connected via a gate circuit (6) to the output of the clock generator (5). The input for the command to set the down counter preset (4) is introduced to the output of the second delay circuit (7), which is connected to the synchronization input of the ultrasonic thickness gauge (1). The outputs of the back counter (4) are connected to the inputs of the decoder (8), the output of which is connected to the first input of the bistable flip-flop circuit (9), the second input of which is connected to the synchronization output of the ultrasonic flaw detector (10). The output of the bistable flip-flop circuit (9) is connected to the second input of the gate circuit (6) and to the ultrasonic flaw detector circuit (10).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

When testing sheets or other products with a constant wall thickness, ultrasonic echoes coming from either the entire or partial thickness of the article are selected. The gate pulse is used to select these echoes, the orifice whose start is delayed by a constant time with respect to the moment when the ultrasonic pulse passes to the test item. However, for example, the sheet metal may vary. Therefore, the duration of the gate pulse must be set shorter so that the end echo can never reach the gate. This is disadvantageous, however, because the steel sheet is not tested when its thickness increases. However, the thickness is not constant and therefore the thickness must be manually adjusted in an automated machine. This sometimes requires testing to be stopped and the setting must be carried out by qualified personnel.

The above drawbacks are eliminated by the wiring for the self-adjusting diaphragm for selecting the ultrasonic echoes according to the invention, which is based on the connection of the counter preselection inputs with the ultrasonic thickness meter and the synchronization output of the ultrasonic thickness meter connected to the input of the second delay circuit. The reverse counter clock input is connected to the output of the clock frequency generator via the gate circuit, while the counter preset command input is output to the second delay circuit output. The counter outputs are routed to the decoder inputs, the output of which is connected to the first input of a bistable flip-flop, the second input of which is connected to the synchronization output of the ultrasonic flaw detector. The output of the bistable flip-flop is connected to the second gate circuit input and the echo selection circuit in the ultrasonic flaw detector. The wiring can be completed by inserting a digital inverter between the outputs of the ultrasonic thickness gauge and the reverse counter preselection inputs. a first delay circuit for the synchronization output of the ultrasonic thickness gauge

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- 2 A new effect is achieved by the ultrasonic thickness gauge detecting the thickness of the object and bringing it into memory ·

According to this, the aperture duration is digitally set.

The attached drawing # shows an example of a wiring for automatically adjusting the elon for selecting ultrasonic esh according to the invention.

The wiring consists of a digital switch 2, which inputs are connected to the ultrasonic thickness meter 1 and its clock input is connected via the first delay circuit 2 the ultrasonic thickness meter 1 synchronization output. The outputs of the digital inverter 2 are connected to the reverse counter preset inputs whose clock input is connected to the output of the clock generator 2 via the gate circuit 6. decoder inputs 8. The output of the decoder 8 is connected to the first input of the bistable flip-flop 2, the second input of which is connected to the synchronization output of the ultrasonic flaw detector 10, and the output of the bistable flip-flop. the echo circuitry in the ultrasonic flaw detector 10 · The ultrasonic thickness gauge outputs Výstup can be directly connected to the input for preselection counter £ backwards · The decoder 8 further includes an adjustable number selector · The ultrasonic thickness gauge 1 works together with the ultrasonic flaw detector 10 ·

Both instruments are part of degectoscopic equipment for mechanized or automated testing · Ultrasonic thickness meter 1 is digital and at its output is usually a transducer, ie · paid by steam, where is stored eg in BCD Mode ·

This information is passed to the numerical inverter 2 at the desired time. The handover time is controlled from the synchronous output of the ultrasonic thickness gauge JL either after one or more thickness measurement cycles. · To ensure that the handover occurs after the measurement cycle is complete and stable, the transfer signal delayed by the first delay circuit 2 · The information from the digital inverter 2 is transmitted with a delay set 3 236 177 in the second delay circuit £ to the preselection of the counter £ backwards and the clock input of the counter £ backwards pulses from the clock generator 2 it is given by the accuracy and resolution with which the duration of the iris diaphragm is to be adjusted for signaling internal material defects. The clock pulses are usually applied through the gate circuit 6 only for the duration of the orifice.

When testing the material by ultrasound, it is necessary that there is a certain safety time interval between the end of the orifice and the rise of the end echo to ensure that the end echo never invades the flaw detector. This interval is set digitally by means of a decoder 8 located at the rear of the counter output. When the decoder 8 is set to zero, the aperture ends with the rise of the final e * ha. This pulse, which indicates the aperture of the aperture, closes the bistable flip-flop circuit. Therefore, the second flip of the floppy flip-flop 2 ⁸ 2 synchronizes the echo ultrasonic flaw detection circuitry 10 ·

The circuitry according to the invention is applicable in all internal defect detection devices which are in their entire thickness.

Claims (3)

SUBJECT MATTER 236 177 1 * Self-adjusting diaphragm for ultrasonic echo nitro selection by a muted defect equipped with a test item thickness meter, characterized in that the ultrasonic thickness meter (1) and the synchronization output of the ultrasonic meter (1) are connected to the back preset inputs t4). thickness is connected to the input of the second delay circuit (7), wherein the reverse clock input of the counter (4) is connected via the gate circuit (6) to the output of the frequency clock generator (5), while the input for the reverse counter preset command applied to the output of the second delay circuit (7) and the outputs of the counter (4) back are routed to the inputs of the decoder (8), the output of which is connected to the first input of the bistable flip-flop (9). 10), wherein the output of the bistable flip-flop (9) is connected to the other the input of the gate circuit (6) and the circuit for defect selection in the ultrasonic flaw detector (10) · Connection according to claim 1, characterized in that a digital inverter (2) is inserted between the outputs of the ultrasonic thickness meter (1) and the counter preselection inputs (4) whose clock input is connected via a first delay circuit (3) to a synchronization ultrasonic thickness meter output (1) · thickness Connection according to point h, characterized in that the decoder (8) comprises an adjustable number selector ·