SU1229643A1 - Arrangement for measuring number of load cycles at strength testing - Google Patents

Abstract

The invention relates to a measurement technique, can be used during cyclic strength tests and provides the ability to measure the number of loading cycles during acceleration cyclic testing of objects that are cyclically loaded with an electric drive on a test bench. The signals from the rotation speed sensor of the object are formed into square-wave signals and are counted by a counter, from the output of which the code corresponding to the number of loading cycles and converted in the decoder is fed to the input of the display unit. Upon reaching a predetermined number of cycles, the counter generates a command signal, which is used to stop the stand electric drive. 1 il. w (L rsD tsD O5 4 GO

Description

The invention relates to a metering technique and can be used in cyclical strength tests.

The purpose of the invention is to provide measurement capability during acceleration cyclic testing of objects.

The drawing shows a block diagram of the proposed device.

The device contains serially connected speed sensor 1 vra, object, galvanic isolation unit 2, comparison unit 3, pulse shaper 4, counter 5, decoder 6 and impedance unit 7, adjustable reference source 8 and cycle number setting unit 9 . The adjustable source 8 of the reference voltage is connected to the second input of the comparison unit 3, and the number of cycles setting unit 9 is connected to the installation input of the counter 5. To ensure that the device continues to operate when the counter 5 overflows, the connected counter 10, the decoder 11 and the display unit 12.

The device works as follows.

The test object is loaded on a bench from an electric drive (not shown), the change in speed of which is specified in a control system (not shown). The signals from the rotational speed sensor of the object, for example, a trapezoidal shape, through the galvanic isolation unit 2 are fed to the input of the comparison unit 3, in which they are compared with the reference voltage supplied from the adjustable reference voltage source 8, and the unit 3 outputs the result as two levels logical signals. These signals

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through the pulse shaper 4, which generates signals in amplitude and steepness, it is fed to the input of counter 5, which counts the number of signals and outputs the result in the form of a code corresponding to the number of loading cycles. This code is converted in the decoder 6 and is fed to the input of the block / display. When the number of cycles predetermined in block 9 is reached, the counter 5 generates a command signal, which through the decoder 6 is fed to the control system and stops the electric drive of the test bench.

Claims (1)

Invention Formula A device for measuring the number of loading cycles when testing for nebrost, containing a unit for setting the number of cycles and a series-connected comparison unit, a pulse shaper, a counter and an indication unit, characterized in that, in order to enable measurement during acceleration-cyclic testing of objects, it is equipped an object speed sensor, a galvanic isolation unit, an adjustable reference voltage source and a decoder, an object rotation speed sensor through a galvanic isolation unit connected to the input of the comparator unit, with the second input of which an adjustable source of voltage is connected, the unit for setting the number of cycles is connected to the installation input of the meter, and a decoder is installed between the meter and the display unit.