SU562921A1 - Proximity switch inductive switch - Google Patents

Description

The invention relates to contactless switching devices for switching alternating currents and voltages with an appropriate electrical circuit and for switching direct currents and voltages and can be widely used in various areas of national economy, especially where it is required to ensure explosion-fire safety, reliability and durability.

. Inductive contactless switches are known that use magnetically saturated gknc cores by means of magnetic fields of permanent magnets that can approach the cores, thereby changing the magnetic permeability of the cores and, therefore, the inductance of the windings located on them 1 - 5.

Other inductive switches use a change in coil inductance from approaching coils or inserting magnetically conductive cores into the coils.

The closest in technical essence to the proposed is a magnetic switching device containing a permanent magnet in the form of a hollow cylinder, inside of which a core of magnetically soft material in the form of a ring is placed, on which the inductors are located, the drive element with a movable magnetic screen and springs .on return drive 1st item.

In the normal state, the hearts are magnetized to saturation by means of a permanent magnet. The p1 impedance of the winding of the core increases with a decrease in the magnetic flux of the permanent magnet, which is inductively coupled to the core.

The flux linkage between the two magnetic elements (the core and the permanent magnet) is reduced by either moving the permanent magnet or introducing a magnetic screen between the permanent magnet and the core.

A disadvantage of this device is the presence of a magnetic system, which is necessary to change the inductance of the core coil on the core and the mutual inductance between them.

The aim of the invention is to simplify the design of the switch.

This is achieved by the fact that in a contactless inductive switch comprising a housing, a drive element, a core of magnetically soft material on which an induction coil is placed, and a screen, the inductance coil is made of a multilayer of resilient electrically conductive material in the form of at least two coaxially placedJ

One another in cylindrical coil springs of different diameters and opposite guides, while the TOipeu coil with terminals rests on one cup of armor core, forming a rigid connection with the case, and the other end of the coil rests on another cup of armor core rigidly connected to the drive element .

FIG. 1 shows a switch with a drive element in the unpressed position; in fig. 2 - switch with the actuator in the depressed position; in fig. 3 is a circuit using the proposed switch for switching DC voltages and currents.

In the case / there is a cup 2 of an armored core, on which the end of the coil with inductance 3, 4 is made of elastic electrically conductive material, for example beryllium bronze, in the form of two coaxially disposed axes in the other cylindrical helical strings | Jn 5, 6 Laz: Root diameters and with the opposite direction of winding.

The other end of the drilling tool 5, 6 rests on the cup 7 of the core, which is rigidly connected to the drive element 8. This element is also rigidly connected to the screen 9, which is inserted into the cylindrical groove 10 of the housing 1 with another free end. The screen 9 has longitudinal grooves 11 in which there are pins 12 preventing angular movement of the drive element 8 relative to its axes and limiting longitudinal movement along the axis during its return movement under the action of springs. The terminals 3, 4 of the inductance coil can be connected to the electrical circuit 13, located on the board 14, having the terminals of the tube 15.

The inductance coil can be made multi-layered, wound from a single wire or consisting of individual cylindrical springs of the required diameter, the upper ends of which must be electrically connected by soldering or welding, and the bottom ends are pulled out through the cup of the armored core rigidly connected to the housing. In this case, the inductor plays the role of a spring return drive element.

The diameter of the spring 5 is limited to the internal diameter of the cups of the armored core, and the diameter of the springs 6 is the diameter of the cores of the core cups.

In the initial position of the drive element shown in FIG. 1, the cup of the armor core is separated from one another at a distance equal to the travel of the drive element of the switch.

The presence in this case of an air gap between the cups of the s.rdechnik’s two-shield furnace. Small effective magnetic permeability .. - p

62921

bridge armor core (and: 1ductiznost1, coil is minimal).

When pressed by an external force, the drive element 8 compresses the double spring 5, 6 of the inductor and takes the position shown in FIG. 2, in which the cup of the armor core is closed (the inductance of the coil is maximum). The use of armored cores of type B-13 with magnetic permeability of c-2000, with 12 turns in each spring (made of beryllium bronze), at a button stroke of 4 mm and pressing force of 1.2N provides an absolute change in inductance from 5-8 µH to 400 -700 µH. i.e. the change in inductive resistance for alternating voltages reaches 40 dB.

For switching DC voltages and currents, an electrical circuit (phi1G. 3) can be used, containing an alternating voltage generator 16, an RL divider circuit 17, an alternating voltage detector for 18, a key output stage 19.

Especially effective is the use of such switches in the keyboard for entering information in a computer, where there are clock pulses of a certain frequency that can be fed directly to the control RL circuit.

Formula of invention

A contactless inductive switch, comprising a case with a driving element installed in it, a heart of magnetically soft material on which an inductance coil is placed, and a screen, so that, in order to simplify its design , the inductance coil is made of a multilayer of elastic electrically conductive material in the form of at least two coaxial helical springs co-located in one another and of different diameters; an armored core is used as the core, one cup and which is rigidly connected to the body, and the other with a driving element, and the inductance coil is placed so that one of its ends with leads rests on a cup of the armored core rigidly connected to the orpus and the other end on the cup of the armored core, sister connected to the drive element, the inductor at the same time serves as a spring return of the drive element.

Sources of Information

taken into account in the examination:

1. US patent L 3638221.

36-5, class 3401972.

2.Pateit USA L 3638222,

340-365,

to l 1972.

3.Patent UK No. 346128, cl. H 3 B, 1972.

Japan

Patent

four.

44-31893, series VI,

Sat 1-607, 1969.

5. The patent of Germany No. 1928924, cl. 21a, 36/18, 1970.

6. US patent number 3668697, cl. 340-365, 1972.

7. Patent of Great Britain No. 1284127, cl. And 3 In, 1972.

8. Patent of Great Britain No. 1364437, cl. H 3 X, 1971.

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