SU1583848A1 - Apparatus for impact tests of piezoelectric transducers - Google Patents

Abstract

The invention relates to a measurement technique and can be used to calibrate piezoelectric transducers and shock accelerometers. The aim of the invention is to increase the reliability of the test results. The goal is achieved by the fact that in a test device containing a waveguide 1 with a test piezo transducer 2 fixed at its end, a recorder 3, a percussion mechanism 4 and a recorder triggering unit, the trigger unit contains a position converter 5 whose output is connected to the first input of the element 6, with the input of the entry of the first counter 7 and through serially connected inverter 8 and the first one-shot 9 with the installation input of the trigger 10. The reset input of the trigger 10 is connected to the output of the element OR 6, and the output to the enable inputs of the first Meters withstand 7 and the second counter 11. Counter inputs of both counters 7 and 11 are connected to the generator 12 pulses. The output of the piezoelectric transducer 2 is connected via a pulse shaper 13 to the second input of the element OR 6 and to the input of the second counter 11, the output of which is connected through the second one-shot 14 to the trigger input of the recorder 3. The installation inputs of the second counter 11 are connected to the bit outputs of the first counter 7, and the installation inputs of the latter - with the outputs of the unit 15 of the pre-launch setup. 1 il.

Description

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The invention relates to a measuring technique and can be used to calibrate piezoelectric transducers and impact accelerometers.

The aim of the invention is to increase the reliability of the test results.

The drawing shows a circuit for shock testing. -

The device contains a waveguide 1 with a piezoelectric transducer 2 connected to recorder 3 fixed at its end, a percussion mechanism 4. At the end of waveguide J, a position transducer 5 is installed, its output is connected to the first input of the element OR 6, to the recording input the first counter 7 and through the serially connected inverter 8 and the first one vibrator 9 with the installation input of the trigger 10, the reset input of which is connected to the output of the OR 6 element, and the output to the counting enable inputs of the first 7 and second 11 counters. The counting inputs of both counters are connected to a generator of 12 pulses. The output of piezolreater 2 is connected via a pulse generator JQ 13 to the second input of the element OR bis input to the input of the second counter 11, the output of which is connected through the second one-oscillator

14 with recorder trigger input 3. Setup inputs of the second counter

11 are connected to the outputs of the bits of the first counter 7, and the installation inputs of the latter are connected to the outputs of the block

15 installation pre-launch. The device works as follows.

In the initial state, when the hammer of the percussion mechanism 4 is not cocked, the output of the transducer 5 of the slot-type position will be the voltage corresponding to a logical zero. The trigger 10, by the common reset signal, is in the state of prohibition of counting by the counters 7 and 11. When the striker 4 is locked, its flag goes out of the slot of the position converter 5, and a voltage corresponding to the logical one appears at the output of the transducer element ILE 6, sets trigger 10 to the state of prohibiting counting for counters 7 and 11 or confirms this state and at the same time raises

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solves the insertion of a number in the reverse code into the counter 7 of the block 15 of the launch anticipation installation. The preset number in block 15 corresponds to the delay of the observed pulse relative to the beginning of the screen of the recorder 3. This number in the binary code determines the position of the recorder pre-trigger switch (oscilloscope sweep duration switch).

Upon impact, when the striker does not reach 0.5–5 mm before the shock end of waveguide 1, the flag of the impact mechanism 4 passes the slot 5 of the position converter, and at the output of the latter a logical zero appears, setting the trigger 10 through the inverter 8 and the one-shot 9 The calculation of the resolution resolution of the pulses of the counters 7 and 11. The first counter 7 performs the summation of the pulses from the generator I2 so that it first supplements the preset content until it overflows, and then after zeroing it continues the counting. Counter 11 is in subtraction mode.

Upon impact of the striker in the waveguide 1, a shock wave is excited, which after a certain time reaches the piezoelectric transducer 2, at the output of which a signal appears. This signal is fed to the recorder 3 and the pulse shaper. The impulse from the driver, having passed the element OR 6, sets the trigger 10 to the state of prohibiting the counting for the counters 7 and 11 and simultaneously enters the contents of the counter 7 into the counter 11.

The first hit is set when the counter 11 is entered a number equal to the time interval from the moment the logical zero appears at the output of the position converter before the strike of the striker until the time when the signal of the piezotransducer 2 appears minus the set delay on the start advance setting unit 15.

All subsequent shocks are operational, and the device operates as described above, while the second counter 11 at the time of zeroing generates a signal which, through the one-shot 4, triggers the sweep of recorder 3. Each time a hit occurs, the delay time is monitored. for subsequent impact, in connection with which the signal under investigation appears at exactly the same place on the recorder screen.

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An adjustable, proactive triggering of the recorder allows the analysis of the entire shock pulse from the test nozoelectric converter, including the initial section.

invention formula

A device for percussion testing of piezoelectric transducers, a 9containing waveguide with a piezoelectric transducer installed on its end, a percussion mechanism, a recorder and a start-up unit, characterized by the following topics: of the inverter, tpnrrepa, the first and second counter of the Element OR, the pulse driver, the start-up pre-set unit and the pulse generator, with the output transforming the position bodies are connected to the first input of the OR element, to the input of the entry of the first counter and through the series-connected inverter and the first one-oscillator to the installation input of the trigger,

g whose reset input is connected to the output of the OR element, and the output to the counting enable inputs of the first and second counters, the counting inputs of which are connected to the pulse generator,

 the output of the piezoelectric transducer through the pulse shaper is connected to the second input of the OR element and to the input of the second counter, the setup inputs of which are connected to

0 inputs of the corresponding bits of the first counter, the installation inputs of the first counter are connected to the corresponding outputs of the pre-launch setup block, and the output of the second

5 counter through the second one-shot is connected to the trigger input of the recorder.

Claims (1)

Claim A device for impact testing of piezoelectric transducers, containing a waveguide with a piezoelectric transducer installed and its end face, an impact mechanism, a recorder, and a Sgo trigger unit, characterized by 20 Sem, which, in order to increase the reliability of the test results, the Registrar Launch block is made in the form of a position transducer, the first second single-vibrator, inverter, 25 Trigger, first and second counters, OR element, pulse shaper, start-up anticipator, and pulse generator, the output the position transmitter is connected to the first input of the OR element, with the input of the first counter and through the inverter and the first one-shot connected in series with the installation input of the trigger, the reset input of which is connected to the output of the OR element, and the output is connected to the resolution enable inputs of the first and second counters the inputs of which are connected to the pulse generator, the output of the piezoelectric transducer through the pulse shaper is connected to the second input of the OR element and to the input of the second counter, the installation inputs of which connected to the inputs of the corresponding bits of the first counter, the installation inputs of the first counter are connected to the corresponding outputs of the installation block pre-emptive start, and the output of the second counter through the second one-shot is connected to the start input of the recorder.