SU1420344A1 - Displacement transducer - Google Patents

Abstract

This invention relates to a measurement technique. The goal is to reduce the dimensions of the transformer sensor of linear displacements and reduce its temperature measurement error due to the asymmetric implementation of its magnetic system in the working and compensation parts. Successively connected sections of the excitation winding 4 and differentially connected sections of the measuring winding 5 are placed on the central core 3 of the cross-shaped magnetic circuit 2 of the sensor. The length of part 8 of the central rod protruding above the surface of the magnetic circuit from the side of the balancing plate 6 is chosen less than the length of part 9 of the central rod protruding above the surface of the magnetic conductor from the side of the movable core 7 of the sensor, and taking into account the experimentally obtained mathematical expressions. 1 il. with S6 (L

Description

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The invention relates to instrumentation technology and can be used to measure linear displacements and distances to the object of control.

The purpose of the invention is to reduce the size of the sensor and reduce its temperature error in measuring displacements due to the asymmetric performance of the compensation part of its magnetic system relative to the measuring part.

The drawing shows the design of the displacement sensor.

The differential-transformer-type displacement sensor contains a ferromagnetic case 1, inside of which a cruciform magnet duct 2 is placed, having a central rod 3. In the middle part of the rod 3, there are located five sections of the winding section 4 of the winding section and a pair of differentially connected sections of the winding 5 of measurement. On one side of the magnetic conductor 2, there is placed with a gap t, a clamping plate 6, mounted with peelability for adjusting and balancing the sensor and forming, together with one of the sections of the winding 5, the compensation part of the sensor. On the side of the other end of the magnetic circuit 2, the movable bore 7 is placed with a gap, which, in the course of the measurement, is connected with the test object and forms the working (measuring) part of the sensor together with another section of the winding 5. The central rod 3 is designed in such a way that the length 1 protruding above the surface of the magnetic wire 2 of part 8 of the central core 3 of the magnetic conductor from the side of the balancing plate 6 is selected from the conditions

(one)

DJ | .a

 Lo-L-h- (U 1), (2)

de Dg - inner diameter of the building en

sa 1; LO distance from internal

the surface of the balancing plate to the end of the magnetic conductor i facing the core

L is the length of part 9 of the central rod 3 protruding above the surface of the magneto55

Q

about 5 5

S

0

n

five

wires in the working part of the sensor

h - The thickness of the magnetic circuit 2 between the pairs of sections of the windings of the sensor

c / p - the initial gap between the end face of the magnetic circuit 2 and the core 7,

 S is the cross-sectional area of the central core 3 of the magnetic core of the sensor body 1, respectively. Initial sensor adjustment is performed when the conditions are met.

-

f. - i

Since (/ j, the mathematical expression (2) determines the ratio between the part 8 of the central core 3 of the magnetic core and the initial gap Gy between the end of the magnetic core 2 and the sensor core 7. It was established experimentally that i (0.1-0.4) D6H displacement differential transformer type works as follows.

When balancing the sensor by moving in its initial position with the balancing plate 6, the magnetic resistances of the working and compensation parts of the sensor are equal, resulting in the emf on both differentially connected sections of the measurement winding 5 being equal and the sensor output signal is zero. As the movable core 7 moves away or approaches relative to the working end of the sensor in the X direction, the size of the working gap dip increases or decreases, while the size of the compensation gap y. remains unchanged. As a result, the resulting voltage is removed from both differentially connected sections of the measurement winding 5. The direction of travel information is indicated by the output signal increment. The choice of the optimal length 1 of part 8 of the central core of the magnetic core in accordance with (1) and (2) allows reducing the size of the sensor and ensuring that the parameters of its working and compensating parts are identical. In addition, when the ambient temperature t ° changes, the relative change in the gap f in the compensation part of the sensor decreases, as a result of which the temperature error decreases.

Claims (1)

Formula invented1 A differential-transformer-type displacement sensor containing a ferromagnetic body, a magnetic core placed inside it with a central rod, a balancing plate and a measles for communication with opposite ends of the magnetic core mounted for displacement opposite the opposite ends of the magnetic core located on the middle part of the rod. with the object of control, in view of the fact that, in order to reduce the size of the sensor and reduce the temperature error of the measurement of displacements, 1 projecting above the surface of the central magnetic sterzhso side balun plastivybrana of conditions I f L  1 st -rcr (1+), Where 0 Dfth LO. five 0 five  with L h. inner diameter of the case j distance from the inner surface of the balancing plate to the end face facing the core of the magnetic core a I the length of the central rod, protruding above the surface of the magnetic core from the side of the core; the thickness of the magnetic circuit between the pairs of sections of the windings of the sensor; the head gap between the end of the magnetic core and the core the cross-sectional area of the central core of the magnetic circuit and the sensor housing, respectively.