SU905656A1 - Device for measuring plate vibration parameters - Google Patents

Description

(5) DEVICE FOR MEASURING VIBRATION PARAMETERS

I

The invention relates to a vibration measuring technique and can be used to determine resonant frequencies, natural modes of vibration, and the magnitude of the absolute vibration of board points.

A device for measuring vibration is known, which comprises a system for sequentially scanning sensors for an absolute vibration of an object, a generator of synchronizing pulses,. amplifier, filter and recording device. This device allows for multipoint measurements 11.

The drawback of the device is the absence of a phase indication, which leads to difficulties in determining its own waveform.

Closest to the invention is a device for measuring vibration parameters of the boards, comprising a vibrating table, a monitoring sensor mounted thereon and a series of

Fee

an amplifier, a limiter, a parallel counter, a decoder, and an electronic switch 21 are connected to it.

Claims (2)

The disadvantage of this device is its narrow functionality, i.e. the inability to directly determine the board's own waveform, since a signal equal to the vector sum of the vibrations of the vibrating table, and the vibrations of the board relative to the vibrating table, is removed from the control sensors serving as transducers. At resonance due to the phase shift of relative oscillations, by 90, and also due to the opposite direction of movement of different points of the board at the same time point at resonant frequencies of the highest order and vectorial summation of relative oscillations with vibrations of the vibration table, the obtained vibration amplitude distribution on the board differs sharply from the board's own waveform form. In addition, due to the lack of indication of the phase of relative oscillations, it is impossible to determine the direction of movement of each board point under study at a given time. The purpose of the invention is to expand the functionality. This goal is achieved by the fact that the device is equipped with relative vibration sensors connected to the signal inputs of the electronic switch and designed to be installed between the board and the vibrating table. The drawing shows a diagram of the device. A device for measuring the vibration parameters of the boards contains a vibration table 1, a control sensor 2 mounted on it and an amplifier-limiter 3 connected to it, a limiting amplifier 3, a parallel counter k, a decoder 5 electronic switch 6, relative vibration sensors 7 connected to the signal inputs of the electronic switch 6 and installed between board 8 and vibrating table 1. The device works as follows. A sinusoidal voltage from the reference sensor enters the limiting amplifier 3 where it is converted into square pulses that trigger a parallel counter k. The counter k outputs the sensor number in binary code, which is supplied to the decoder 5. The electronic switch 6 is controlled by pulses from the decoder 5 and connects each vibration sensor 7 to the oscilloscope for a time equal to the oscillation period and with the oscillation phase of sensor 2. B is the result On the oscilloscope screen, 4 waveforms are generated, one by one. signal period of each sensor from-. wearable vibration. In this case, the signal amplitude shows the amplitude of the relative vibration, and the phase the direction of movement, which taken together determines the waveform of the board 8, to determine the distribution of the amplitudes of the absolute vibration on the board 8, it is enough to sum the signal of the relative vibration sensor with the signal of the control sensor. The use of relative vibration sensors in combination with control of the signal from the control sensor favorably distinguishes this device from the known ones, since in addition to determining the distribution of the amplitudes of absolute vibration on the board, it becomes possible to determine the oscillation mode of the Board during forced oscillations. Claims device for measuring board vibration parameters, comprising a vibrating table, a monitoring sensor mounted on it and an amplifier-limiter connected in series with it, a parallel counter, a decoder and an electronic switch, characterized in that, in order to enhance the functionality, it is equipped with sensors relative vibration connected to the signal inputs of the electronic switch and intended to be installed between the board and the vibrating table. Sources of information taken into account in the examination 1. USSR author's certificate number 500776, cl. G 01 H 11/00, 1976. 2. Japanese patent W 447-12826, cl. G 01 H 3/00, 1979 (prototype). E g