JPS61267217A - Non-contact switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Field of invention) The present invention relates to a non-contact switch.

(Summary of the Invention) The present invention provides a non-contact switch that can be miniaturized and can be used even at high temperatures by effectively utilizing an amorphous magnetic material.

(Prior art and its problems) As a conventional non-contact switch of this type, one using a Hall element as shown in FIG. 4 is known.

FIG. 4 is a principle diagram, in which 51 is a Hall element, 52 is a DC power supply that causes current to flow through the Hall cable 51, and 53 is a magnet that applies a magnetic field in a direction perpendicular to the current of the Hall element 51. Although not shown in the drawings, the magnet 53 is connected to a switch operating section, and is provided so as to be movable in directions toward and away from the Hall element 51. If the distance of the magnet 53 is changed relative to the Hall element 51, the potential differences generated in the directions perpendicular to the current and the magnetic field will change in accordance with the change.

This output voltage is taken out, and the output voltage is compared in magnitude with a set level as a reference, thereby producing an on-off output.

However, each of the conventional examples having such a configuration has the following drawbacks.

That is, the Hall element has poor temperature characteristics and a maximum operating temperature of 100° C. or lower, so it cannot be used at high temperatures and has the drawback of lacking versatility.

Furthermore, since the detection magnetic field is as large as 0.1 to 0.010 e, it cannot be detected unless there is a large change in the magnetic field. Therefore,
In order to reliably produce on/off output, the magnet must be moved over a relatively large range, and a large space is required to move the magnet, resulting in an overall large size. Furthermore, in order to make the magnetic field and the voltage output direction perpendicular, the Hall element must be formed with a surface perpendicular to the magnetic field, and it cannot be made into a thin shape, which imposes restrictions on installing it in various devices. It had the drawback of lacking versatility.

(Objectives of the Invention) 1 The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the versatility by making it possible to reduce the overall size and to be able to use it even at high temperatures. .

(Structure and Effects of the Invention) In order to achieve such an object, the present invention includes a magnet that is moved and operated in conjunction with a switch operation section, and a magnet that is provided at a position that moves near and far from the magnet as the magnet moves. an amorphous magnetic material, a primary coil wound around the amorphous magnetic material and excited by a high frequency current;
Voltage is induced by electromagnetic induction from the next coil2
The secondary coil is configured to include a secondary coil, and an output means that takes out the induced voltage of the secondary coil and outputs an on/off output.

According to this configuration, by simply moving the magnet and the amorphous magnetic material closer to each other, when the magnet is away from the amorphous magnetic material, the magnetic flux of the magnet does not reach the amorphous magnetic material, so that the magnetic flux of the magnet does not reach the amorphous magnetic material. The high-frequency magnetic flux passes through the amorphous magnetic material and acts on the secondary coil, and a large level of induced voltage is output from the secondary coil. On the other hand, when a magnet approaches an amorphous magnetic material,
The magnetic flux of the magnet reaches the amorphous magnetic material, and this magnetic flux causes saturation of the magnetic flux in the amorphous magnetic material, reducing the level of the induced voltage output from the secondary coil. Based on the level difference of this induced voltage, an on-output or an off-output can be output by comparing the levels at an appropriate threshold value.

Therefore, since the amorphous magnetic material is a metal, 2
It can be used up to 00°C, expanding the operating temperature range and improving versatility.

In addition, since the magnetic flux saturation phenomenon of amorphous magnetic material is utilized, there is no restriction between the magnetic field and the voltage output direction, and
Thin wire can be used as the amorphous magnetic material, the overall structure can be thin and small, and it can be easily installed in various devices, making it extremely versatile.

(Description of Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is an overall vertical sectional view of a non-contact switch according to an embodiment of the present invention, and FIG. 2 is a circuit diagram. In these figures, ■ is a cylindrical casing, and an actuator 3 with a switch=4-operating part 2 protruding from one end in the longitudinal direction is inserted into this casing l so as to be movable in the force direction of the sleeve center. has been done.

A cylindrical magnet holding member 4 is fitted into the actuator 3, and a magnet 5 is integrally held by the magnet holding member 4.

A coil spool 6 as a core material is provided inside the casing l at the other end in the longitudinal direction than the magnet 5, and an amorphous thin wire 7 as an amorphous magnetic material is inserted into the center of the coil spool 6. The amorphous thin wire 7 includes a primary coil 8 which is excited by a high frequency current, and a primary coil 8 which is excited by a high frequency current.
The secondary coil 9, in which a voltage is induced by electromagnetic induction from the secondary coil 8, is wound in a mutually insulated state.

A coil spool holding member 10 is integrally connected to the coil spool 6, and a compression coil spring 11 is interposed between the collar portion 10a of the coil spool holding member 10 and the bottom portion of the magnet 5 side of the magnet holding member 4. It is configured such that the magnet 5 can be pushed toward the amorphous thin wire 7 while maintaining the operating portion 2 in the protruding position while resisting the biasing force of the compression coil spring 11.

The coil spool holding member 10 is screwed onto the casing 1 and its fixed position is regulated by a nut 12.
This tightening is performed so that the pressing force applied to the switch operating section 2 can be adjusted by adjusting the fixing position of the nut 12. 13 is a pull-out cable, I4 is a waterproof O-ring for sealing between the switch operation part 2 and the casing 1, and 15 is a coil spool holding member 1.
0 and the casing 1, and between the pull-out cable 13 and the nut 12, the waterproof backing is designed to effectively prevent water from entering the casing l. There is.

Reference numeral 16 denotes an output means for extracting the induced voltage of the secondary coil 9 and outputting an on/off output, and 17 is a high frequency power source. The output means 16 includes an amplifier 18, a peak detection circuit 19, a comparator 20, and an output circuit 21.

Next, the operation of this embodiment will be explained using the waveform diagram of FIG. 3.

When the primary coil 8 is excited by the high frequency power supply 17, 1
As shown in (a), a high-frequency current is generated in the secondary coil 8, and as a result, in the secondary coil 9, as shown in (b), an instantaneous current is generated corresponding to the zero-crossing point of the high-frequency current. generates an induced voltage.

At this time, if the switch operation part 2 is not operated and the magnet 5 is farther away than the amorphous thin wire 7, a high level voltage will be generated, and conversely, the switch operation part 2 will be pressed and the magnet 5 will approach the amorphous thin wire 7. Due to the saturation of the magnetic flux in the amorphous thin wire 7, the voltage becomes a low level or zero.

As shown in (c), this induced voltage is amplified, then peak detected and integrated, and the comparator 14 calculates
Compare the size with the threshold value set at a predetermined level, and (
As shown in (d), when the level is higher than the predetermined level, the output circuit 2I outputs an on output, and when the level is lower than the predetermined level, the output circuit 21 outputs an OFF output.

The magnet 5 may be a permanent magnet or an electromagnet.

In the present invention, the electric circuit part may be housed in the casing 1 with a built-in amplifier, but in order to further reduce the overall size, the amorphous thin wire 7, the primary coil 8, and the secondary coil 9 are housed in the casing 1. However, it is preferable to adopt a structure in which the lead wire from the secondary coil 9 is installed inside the amplifier 18 provided outside.

In the above embodiment, the switch operating section 2 is provided directly on the actuator 3 that moves integrally with the magnet 5, but in the present invention, for example, the switch operating section 2 is provided at a separate location, and the switch operation The portion 2 and the actuator 3 may be mechanically linked by a link mechanism or the like or electrically linked by a solenoid or the like.

[Brief explanation of drawings]

FIG. 1 is an overall vertical sectional view of a non-contact switch according to an embodiment of the present invention, FIG. 2 is a circuit diagram, FIG. 3 is a waveform diagram, and FIG. 4 is a principle diagram showing a conventional example. 2...Switch operating unit, 5...Magnet, 7...Amorphous thin wire as an amorphous magnetic material, 8...Primary coil, 9...Secondary coil, 16...Output means.

Claims (2)

[Claims] (1) A magnet that is moved and operated in conjunction with a switch operation part, an amorphous magnetic body provided at a position that moves closer and further away from the magnet as the magnet moves, and excited by a high-frequency current wound around the amorphous magnetic body. a secondary coil in which a voltage is induced by electromagnetic induction from the primary coil; and an output means for extracting the induced voltage of the secondary coil and outputting an on/off output. . (2) The amorphous magnetic material is connected to the primary coil.
The non-contact switch according to claim 1, which is an amorphous thin wire inserted into a core material around which a second coil is wound.