RU2464528C1 - Differential mutually inductive displacement sensor - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: sensor includes housing (1) with ferromagnetic screen (9) and cover plates (11, 12) one of which (11) serves as limit stop of stock (10) spring-loaded with spring (7) and designed for communication to the object. Ferromagnetic armature (3) is fixed on the stock. In the housing there coaxially located are two differentially connected inductance coils (2 and 4) and power winding (5). Spring (7) is located on housing (1) and has shell (6) for protection of spring with a tip and contact element (8). Contact element is made in the form of a ball with possibility of rotation. Location of spring on the sensor housing provides the reduction of its dimensions. Available shell for protection of spring with the tip and contact element made in the form of a ball with possibility of rotation provides longitudinal measurements at transverse movements of measuring object and protects the spring against twisting and stock against sticking, thus improving the operating reliability.

EFFECT: improving reliability and reducing the dimensions of the device.

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Description

The invention relates to the field of measurement technology and can be used to control linear movements, for example, to control the thermal movements of equipment and pipelines at nuclear power plants.

Linear displacement sensors of various types are known, including differential-transformer cylindrical sensors [1], consisting of a housing, inside of which two ordinary distributed windings are located on the frame - the primary and secondary measuring windings, consisting of two counter-connected sections separated by a partition . Inside the windings, a movable armature of ferromagnetic material moves, mounted on a rod in contact with the measurement object.

The disadvantages of such sensors include relatively large dimensions and mass, which are determined mainly by the range of measured movements, as well as by elements connecting the sensor to the measurement object. To ensure the linearity of the output characteristic of the sensor, the length of the windings should, as a rule, be 2.5 times the size of the measuring range. In addition, when the sensor is equipped with a return spring located in the sensor housing, the length of the sensor housing increases by the length of the spring.

This is most relevant for sensors designed to measure displacements over 100 mm.

The closest in technical essence to the proposed device is a differential inductive displacement sensor [2].

The sensor contains two coils of inductance placed coaxially, included differentially, and a spring-loaded rod, on which a ferromagnetic armature is fixed. When moving the rod, the armature moves with it, while changing the opposite sign of the inductance of both coils.

The disadvantage of the sensor is its low reliability, due to the impossibility of measuring longitudinal displacements during transverse movements of the controlled object and the large dimensions due to the location of the spring in the sensor body.

The aim of the invention is to increase reliability, reducing size.

This goal is achieved by the fact that in a differential mutually inductive displacement transducer containing a housing with a ferromagnetic screen and covers, one of which serves as a limiter for the movement of a spring-loaded rod intended for communication with the measurement object, a ferromagnetic armature mounted on the rod, two differential coils connected coaxially in the housing inductance, according to the invention, an additional power winding is introduced into it, and the spring is located on the housing and has a glass for protection dinner with a tip and a contact element in the form of a ball rotatably.

Figure 1 shows the design of the sensor.

The differential mutually inductive displacement sensor contains a housing (1) with a ferromagnetic screen (9) and covers (11, 12), one of which (11) serves as a limiter for the movement of the spring-loaded spring (7) of the rod (10), intended for communication with the measurement object, fixed on the rod (10), a ferromagnetic armature (3) located in the body coaxially with two differentially connected inductors (2 and 4), a power winding (5), a spring (7) located on the body (1), designed to return the rod (10 ) to its original position, a glass (6) to protect the ins (7) with the tip and the contact member (8) formed as a ball rotatably.

A differential mutually inductive displacement sensor operates as follows. A controlled linear movement of the measurement object is perceived by the sensor rod (10) spring-loaded with a spring (7). The movement of the rod (10), and with it the ferromagnetic armature (3) relative to the measuring windings (2 and 4) when voltage is applied to the power winding (5) leads to the appearance of EMF modulation in 2 measuring windings (2 and 4), which interconnected according to the scheme shown in figure 2. The magnitude of the EMF modulation depends on the position of the ferromagnetic armature (3).

The electrical signal obtained in this way, through the sealed terminal blocks and the cable line, is fed to the input of the secondary converter for conversion into a digital output code. A spring (7), designed to return the rod (10) of the sensor to its original position, is located outside the sensor housing (1) and inside the cup (6) to protect the spring with a tip and a contact element made in the form of a ball (8), which can be rotated .

The location of the spring on the housing of the sensor reduces its size. The presence of a cup for spring protection with a tip and a contact element made in the form of a ball with the possibility of rotation provides longitudinal measurements during transverse movements of the measurement object and protects the spring from twisting, and the stem from jamming, while increasing reliability.

Information sources

1. L.Kh.Shidlovich. Differential transformers and their application. Energy, 1966.

2. Patent for the invention of the Russian Federation No. 1298514. Differential inductive displacement sensor. V.N. Velichko, S.V. Sinelnikov, registered on June 24, 85.

Claims (1)

A differential mutually inductive displacement sensor, comprising a housing with a ferromagnetic screen and covers, one of which serves as a limiter for the movement of a spring-loaded rod intended for communication with the measurement object, a ferromagnetic armature mounted on the rod, coaxially located two differentially connected inductance coils, characterized in that it additionally contains a power winding, and the spring is located on the housing and has a glass to protect the spring with a tip and contact element It is made in the form of a ball rotatably.

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