JPS5847823Y2 - Commutator motor temperature sensitive brush device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a temperature-sensitive brush device for a commutator motor.The present invention relates to a temperature-sensitive brush device for a commutator motor. The brush piece is directly brought into contact with and separated from the commutator in response to changes in the commutator motor, thereby automatically operating and stopping the commutator motor.

Conventionally, a combination of a thermistor and an electronic circuit, or a combination of a bimetal and a contact point, etc. was used to automatically start and stop a commutator motor depending on the ambient temperature, so these combination devices were installed separately from the motor. It is inserted into the motor's external circuit.

Therefore, not only does it require extra space, but it is also expensive.

The present invention has been devised in view of these points, and one embodiment of the present invention will be described below with reference to the drawings.

1 is a resin bracket for the commutator motor and mounting piece 2.
2, and the base ends of brush pieces 3, 3, which are made of a plate spring material such as bronze and are formed into a substantially U-shape, are attached to the mounting pieces.

A permanent magnet 4.4 is attached to the tip of each brush piece.

Reference numerals 5 and 5 are L-shaped temperature-sensitive magnetic bodies that are attached to through holes 6 and 6 of the bracket 1, respectively, and their respective tips 7 are opposed to the permanent magnets 4.

Further, the base end 8 of the temperature-sensitive magnetic body 5 is located outside the bracket 1 and is sensitive to the ambient temperature of the bracket 1.

Temperature-sensitive magnetic materials have the temperature characteristics of magnetic permeability shown in Figure 6. For example, to explain characteristic 1, when the temperature is lower than 11°C, the magnetic material has a magnetic permeability of several thousand, but when the temperature is higher than 11°C, the permeability is several thousand. Then, the magnetic permeability decreases rapidly and becomes equivalent to a non-magnetic material.

In this way, a temperature-sensitive magnetic material is a material that plastically changes into a magnetic material and a non-magnetic material in response to changes in temperature.

The temperature t1° C. in this case is called the Curie temperature (one Curie point).

There are two types of temperature-sensitive magnetic materials: ferrite based on Mn-Zn, and alloy based on Ni, Cr, Si, and Fe, and the Curie temperature ranges from 40°C to +150°C.
There is a temperature of ℃.

FIG. 2 shows the energized state in which each brush piece 3 is in sliding contact with the commutator 9, and the permanent magnet 4 attached to the tip of each brush piece is attracted to the temperature-sensitive magnetic body 5.

Therefore, the brush piece 3 is pressed against the commutator 9.

This state corresponds to the case where the temperature-sensitive magnetic material 5 is lower than the Curie temperature and acts as a magnetic material, and the commutator motor is in a rotating state.

On the other hand, FIG. 3 shows a non-energized state in which the brush piece 3 is separated from the commutator 9, and the temperature-sensitive magnetic body 5 is in a non-magnetic state as the temperature is higher than the Curie temperature.

Therefore, no magnetic attraction force acts between the permanent magnet 4 and the temperature-sensitive magnetic body 5, and the brush piece 3 returns to its free position due to its own elasticity and loses contact with the commutator 9, causing the commutator motor to The power supply is stopped.

Next, FIGS. 4 and 5 show another embodiment of the present invention, in which the brush piece 3 separates from the commutator 9 when the ambient temperature is lower than the Curie temperature, and the brush piece 3 separates from the commutator 9 when the ambient temperature is higher than the Curie temperature. The mounting positions of the permanent magnet 4 and the temperature-sensitive magnetic body 5 relative to the brush piece 3 are different from those shown in FIGS. 1 to 3.

In the figure, 10 is a rotating shaft, and 11 and 11 are lead wires.

As described above, the present invention fixes a temperature-sensitive magnetic material having magnetic and non-magnetic properties to a bracket at a temperature of one Curie, and permanently attaches it to the tip of a leaf spring-like brush piece whose base end is attached to the bracket. I decided to attach a magnet,
The permanent magnet can be moved toward and away from the temperature-sensitive magnetic body, and the brush piece can be moved toward and away from the commutator depending on the ambient temperature of the commutator motor.

Therefore, the commutator motor can be started and stopped automatically according to the ambient temperature, and compared to conventional devices, the temperature detection means and motor control switch means can be simplified, and the required space and cost can be reduced. It has great practical effects, such as being advantageous.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a bracket showing an embodiment of the device according to the present invention, FIGS. 2 and 3 are plan views of the bracket showing different operating states, and FIGS. 4 and 5 are views of the device according to the present invention. A plan view of a bracket showing another embodiment and corresponding to FIGS. 2 and 3, and FIG. 6 is a temperature characteristic diagram of magnetic permeability of a temperature-sensitive magnetic material. 1... Bracket, 3, 3... Brush piece, 4, 4... Permanent magnet, 5, 5... Temperature-sensitive magnetic material, 9... ... Commutator.

Claims (1)

[Scope of utility model registration request] A permanent magnet is attached to the tip of a leaf spring-like brush piece whose base end is attached to the bracket, and a temperature-sensitive magnetic material that can be moved into and out of contact with the magnet is fixed to the bracket, and the magnet is adjusted to the ambient temperature of the commutator motor. A temperature-sensitive brush device for a commutator motor, wherein the brush pieces are brought into contact with and separated from the magnetic body, and the brush pieces are brought into contact with and separated from the commutator.