RU1778549C - Vibratory transmitter - Google Patents

Abstract

The invention relates to measuring technique and is intended to expand the measuring range of the vibration sensor by providing control of the stiffness of the magnetic suspension of the inertial element. The inertial element is made in the form of a permanent magnet placed between two other permanent magnets fixed on the end edges screwed onto the ends of the housing, with the possibility of changing their axial position. This provides adjustment of the gap between the magnets, on which the stiffness of the magnetic suspension depends. To measure the vibration of the inertial element, Hall elements are used that are located symmetrically with respect to the longitudinal axis of the housing in the plane of the magnetic neutral of the inertial element. 1 s.p. f-ly, 2 ill. 5 Ј ЖМН ./ ё Ч 4 оо еl fc

Description

The invention relates to measuring technique and can be used to measure the vibrations of mechanisms and machines in a wide range of frequencies and amplitudes.

Sensors are known for measuring vibrations with piezoelectric, inductive and other transducers, but they have a number of significant drawbacks leading to measurement errors caused by imperfect mechanical systems and their temperature instabilities.

Of the known solutions, the closest in technical essence to the invention, selected as a prototype, is an inductive vibration sensor containing a cylindrical body, an inertial element placed therein made in the form of a cylindrical permanent magnet, a magnetic suspension of the inertial element made in the form of two permanent of magnets mounted on the ends of the housing, coaxially with the inertial element and oriented by the poles towards the same poles of the inertial element, and the electric trans ateliers.

However, this sensor has measurement errors, because using an inductor as a converter, it is impossible to make accurate measurements, because the magnitude of the induced EMF in the coils depends on the speed and displacement of the inertial magnet, as well as the limited frequency and amplitude ranges of measurements in the form of constant stiffness of the magnetic suspension.

The aim of the invention is to expand the frequency and amplitude range of measurements and increase the accuracy of measurement.

The goal is achieved in that the sensor is equipped with two covers mounted on the threads on the highlander of the housing with the possibility of adjusting the stiffness of the suspension, and the inductive vibration converter of the inertia element is replaced by two Hall sensors placed symmetrically relative to the longitudinal axis of the housing in the plane of the magnetic neutral of the inertial element

In FIG. 1 shows the design of the sensor; in FIG. 2 - its output characteristic.

The sensor (Fig. 1) consists of a three-stage housing 1, 2. Side covers 1 are fastened to the central housing 2 by screwing in the center of which permanent magnets 5 are fixed in the bushings 3 4, directed by the same poles to the magnet b of the seismic mass In the central housing 2, a sleeve 7 is placed in which two Hall elements 8 are mounted symmetrically in the slots. Magnet 6 moves freely in the sleeve. The magnet has the shape of a rectangle and is made of a highly erratic material, for example, KS-37A. The sleeve 7 is fixed in the housing with a screw 9, and to exclude the possibility of rotation of the magnet in the sleeve and reduce

frills along sleeve 7 grooves are cut. The sensor body and covers are made of non-magnetic material. The sleeve 3 ends with a screw, with which it is attached to the measured object. Bushings 3, 4 have

thread and screw into the side covers. A connector is attached to the center of the housing 2 for supplying power and receiving an output signal. Vibration sensor works as follows.

In the initial state, by moving the central sleeve 7, the Hall elements are mounted on the magnetic neutral of the magnet 6 and the sleeve is locked with the bolt 9. Using the side covers 1, the required stiffness of the seismic mass suspension is established depending on the measured frequency and vibration amplitude of the measured object. The voltage at the output of the sensor in the initial state is zero. Then

the sensor is threadedly attached to the measured object. Vibrations of the sensor housing cause the Hall elements to shift relative to the seismic magnet 6, as a result of which an EMF is induced at the output of the Hall elements, the magnitude of which is proportional to the amplitude of the vibrations and the frequency is equal to the vibration frequency of the object. The Hall elements are connected in series, as a result of which a signal change is excluded depending on the deviation of the seismic mass magnet from the axis of the sensor and a twofold increase in the output signal.

Claims (2)

1. A vibration sensor comprising a cylindrical body, an inertial element placed therein, made in the form of a cylindrical permanent magnet, an inertial element magnetic suspension, made in the form of two permanent magnets mounted on the ends of the body coaxially with inertial elements and oriented poles towards the same poles of the inertial element, and an electric vibration converter of the inertial element, characterized in that, in order to expand the frequency and amplitude range, it is equipped with two caps, mounted on the thread on the ends of the housing with the possibility of adjusting their axial position. 2. The vibration sensor according to claim 1, with the exception that, in order to increase accuracy and sensitivity, the electric vibration transducer of the inertial element is made in the form of a pair of Hall sensors placed symmetrically relative to the longitudinal axis of the housing in the magnetic neutral plane of the inertial element, Fig. Ј