Resonance demodulation detection method of mechanical failure impact

Abstract

The invention relates to a resonance demodulation detection method of mechanical failure impact, comprising the following steps: an acceleration transducer installed on a machine to be detected and can flat detect limited frequency band acceleration is used, signals output by the acceleration transducer are transmitted to an electronic resonator processing generalized resonance signals triggered by the acceleration transducer subjected to impact excitation, signals outputted by the electronic resonator are transmitted to a detector, signals outputted by the detector are transmitted to a low-pass filter enable of carrying out smooth filtering to detected unidirectional pulse signals so as to realize the envelope demodulation of the generalized resonance signals of the electronic resonator, and finally resonance demodulation detection results are outputted by the low-pass filter. The resonance demodulation detection method of mechanical failure impact is characterized in that the acceleration transducer is a high-frequency generalized resonance peak acceleration sensor with the frequency characteristic containing frequency F1, the resonance frequency F2 of the matched electronic resonator is equal to or smaller than the frequency F1 of the acceleration transducer, and the electronic resonator selects the signals generated by the acceleration transducer subjected to the impact excitation and equal to the generalized resonance frequency F1 of the acceleration transducer or converts the signals of the generalized resonance frequency F1 of the acceleration transducer into generalized resonance signals of the frequency equal to F2 and outputs resonance demodulation signals through the detection of the detector and the smooth filtering of the low-pass filter.

Description

technical field [0001] The invention relates to a fault detection technology, in particular to a mechanical fault impact detection method using resonance demodulation technology as a detection means. It is mainly used to detect the impact caused by the short-term collision of two parts caused by fault defects or improper movement between bearings, gears, wheel rails and relative moving parts inside mechanical components, so as to identify the existence and evaluation of the fault The impact of the failure. Background technique [0002] The safety inspection of product operation requires a method to detect the short-term impact caused by the internal fault of the machine in motion. The detection object and method are different from the traditional concept of shock test detection for products out of operating conditions. [0003] There are already national standards, such as the GJB-150.81-86 mechanical shock test standard, to conduct shock tests on products and packaged prod...

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Problems solved by technology

[0010] The shock signal time faced by the traditional shock test standard is long, and the spectrum range of the shock wave is low. For example, the first zero point of the spectrum of the 200us half-wave sine shock is about 7.5kHz, and the first zero point of the 200us square wave shock spectrum is about 5.0kHz. ,like Figure 1-1~1-4 As shown, the shock waveforms involved in these traditional shock tests are easily detected with existing accelerometers (which have a flat frequency response to 20kHz)

However, the pulse width generated by the impact caused by the fault damage inside the machine is more than an order of magnitude smaller than the width specified in the impact test standard. For example, the first zero point of the spectrum of the 20us half-wave sine shock is about 75kHz, and the first zero point of the 20us square wave shock spectrum is about 75kHz. The zero point is about 50kHz, such as Figure 2-1~2-4 As shown, the shock waveform in these specific environments cannot be detected with the existing acceleration sensor (its flat frequency response reaches 20kHz, and the flat frequency response required by the international standard must reach 10kHz), but a sensor with a frequency response of up to 200kHz is required. detection, and such a sensor is difficult to manufacture; especially, even if there is such a sensor, the AD converter for its signal detection requires a sampling frequency above 1MHz; the more serious problem is that the signal amplitude of the mechanical operation fault impact is small , easy to be covered by strong medium and low frequency vibrations, the signal-to-noise ratio of direct detection is very poor, unlike the shock signal in the shock test, which is not only strong, but also has almost no other vibration signals

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