SU166160A1 - - Google Patents

Description

Known methods of automatic aggregation of defects and devices based on these methods. The known method is based on the time selection of signals and consists in the fact that pulses reflected from defects and gating pulses are applied to the time selector, which determine the zone of automatic control of a separate section. The zone of automatic control is formed with the help of pulses from the synchronizer and the setting of the oscillator / duration of the strobing pulse. If there is a defect in the time selector, select the impulses on the iicitojiHHTCvibHOc device). The 1 IptVUiaracMbiii method differs from the one and the same in that the block of formalized gating pulses is given signals reflected from the front and back edges of the product, with the help of which to form the front edge and the back fronts of the gating pulse, respectively. This allows us to give a complete answer to the laps that have different sectored naragle sounding sounds. On fng. i shows a block diagram of an automatic defect scanner; in fig. 2 - its functional diagram. Impulses taken from the plates of the echo flaw detector in the negative polarity (see Fig. 2, a, where / is the probe pulse, 2 are reflected from the milking face) are supplied to the contact point varnant at point a. These im2 plsy come to the limiter /. On the output of the limiter, they will have positives) (iKviiipnocTE-. (See fng. 2, b). The point b is supplied with synchronization of the pulse from the flaw detector (see fig. 2, c). This impulse goes through the non-switch I to the delay line //, the time of which can be regulated. block /// formalized strobe pulse n.pulse, dntel-HOCTii, the temporary provision of which is located in the automated zone t | 10.1. The block of the formal | | avan: 1 strobnuyuyugo nn1ulsa is a thringer assembled on a double TpiKvie. The delayed CIHIXJIOHH Human Sound nm arrives at one of the lamp grids of this trnger and translates it into one of the most stable 1) 1 state. On the other one hundred squares of the trigger trigger, nmnulses from ogr nnchnts.ch / arrive. Imps. reflected from the bottom | -ranium, translates m | igger to the second long stable state. Thus, tpnrrep will form a U-shaped gating pulse (fng. 2,). This impulse, which has a positive polarity, is applied to the time selector IV, unlocking it for the duration of its action.

The time selector IV is designed to select (in time) the signals between the probe and the bottom reflection, i.e., the signals reflected from the defective places. At (lHl4i defect in the controlled product, a negative polarity pulse appears on the anode of the selector lamp, which is fed to the actuator V, controlled its operation. To eliminate the influence of the pulse reflected from the bottom edge on the selector, the pulses applied to the first the grid of the selector lamp is delayed by the delay line VI by an amount approximately equal to 0.05-0.1 μsec.

The feature of the scheme is as follows. The elements of the trigger circuit are selected in such a way that it can go to the second steady state only from a signal separated from the bottom face, whose amplitude is sufficiently large. This is necessary so that signals from defects, usually having much smaller amplitudes, do not affect the formation of the gating pulse.

If the amplitude of the signal reflected from the defect is commensurate with the bottom signal, this will cause the end of the gating pulse to move to the leading edge of the pulse reflected from the defect, and the signaling of the defect will stop. But this is not an obstacle to automatic control, since this defect will be registered at its initial appearance and at disappearance.

The operation of the circuit in the immersion variant springs to the following: the switch I is periodically set to the position // i. When the echo flaw detector is operated in the immersion version, the impulses shown in FIG. 2, e, where Y is the probe pulse; 2 - nmnul is reflected from the front face of the product; 3 - pulse reflected from the bottom facet. After limiting and changing the polarity, these pulses arrive at the time selector IV. The synchronizing pulse of the flaw detectors is fed through the delay line VII, similar to the delay line //, to the block forming the start pulse VIH. This block is a trigger assembled on a double triode. The delayed synchronizing pulse (Fig. 2, g) is applied to one of the grids of the lamp of this trigger and translates it into one of the long-term stable states; pulses from the limiter come to another grid of the trigger lamna /. The impulse reflected from the front face of the product puts the trigger into a second long-lasting steady state. Thus, the trigger will form a U-shaped impulse (Fig. 2, h). This impulse after differentiation through the switch I will go to the delay line II, and later the circuit will work in the same way as when the flaw detector works in the contact version. In this case, the beginning of the automatic control zone will be determined by the impulse reflected from the front edge of the product, which eliminates the need to strictly maintain the distance between the searchable head and the controlled product.

Subject invention

A method for automatically signaling defects for ultrasonic echo flaw detectors, based on the time selection of signals, consisting in that pulses reflected from defects are sent to the time selector, and the strobe pulses from the unit are applied to them, defining the automatic control zone, and output

The time selector is fed to an innational device, characterized in that, in order to control products that have different sections in the direction of sound, the signals from the front and bottom edges of the product are generated on the unit with which the front and rear fronts of the strobes are formed. impulse respectively.