JPS6026532Y2 - Brush wear detection device - Google Patents

Description

[Detailed explanation of the idea] This idea is based on motors and generators (hereinafter referred to as motors, etc.).

) relates to a device for detecting wear of brushes.

A conventional method for detecting the wear limit of a brush that is in sliding electrical contact with a commutator or slip ring of a motor etc. is, for example, as shown in FIG. An insulated wire 3 is inserted and fixed into a hole 2 drilled from the end face to a depth corresponding to the wear limit.

With the above configuration, when the carbon brush main body 1 is worn to the limit, the core wire 5 portion at the lower end of the insulated wire 3 comes into contact with the commutator or slip ring, and the voltage of the commutator etc. is used as a signal indicating the wear limit of the insulated wire. 3 so that it can be obtained from the other end.

In FIG. 1, 4 is a lead wire connected to the carbon brush main body 1.

However, in this type of wear limit detection mechanism, the core wire 5 needs to be electrically separated from the carbon brush body 1 while the carbon brush body 1 is in a normal state. The structure needs to be adjusted so that the core wire 5 at the lower end of the electric wire 3 does not come into contact with the bottom surface of the hole 2 of the carbon brush body 1.

However, with the above method, it is not possible to measure the lower end position of the insulated wire inserted into the hole 2, and therefore the lower end position of the insulated wire 2 cannot be accurately adjusted.
There was a drawback that the detection position of the wear limit varied for each carbon brush.

This idea was made to eliminate the above-mentioned drawbacks, and by folding the insulated wire and inserting it so that the folded end reaches the bottom of the hole provided in the carbon brush body, the core wire of the insulated wire is It is an object of the present invention to provide a brush wear limit detection device that eliminates the need for position adjustment so that the carbon brush does not come into contact with the carbon brush, and that can always accurately detect the wear limit.

An embodiment of this invention will be described below with reference to the drawings.

In Fig. 2, 11 is a square plate-shaped carbon brush body.
A metal fitting 12 for connecting the lead wire is fixed to the upper end portion by a known method such as caulking 13, and a brush lead wire 14 is connected and fixed to this metal fitting 12. It is electrically connected to the main body 11.

The lead wire 14 is connected to a power supply circuit for a motor (not shown) or the like.

Reference numeral 15 denotes a lead wire for detecting wear of the carbon brush body 11. This detection lead wire 15 is an insulated wire in which a stranded core wire 16 is coated with a heat-resistant insulation coating 17. The lower end of the carphone brush body 11 is folded back, and this folded part is attached to the carphone brush body 11.
is inserted into a hole 18 drilled to a predetermined depth from the upper end surface of the
It is fixed by an insulator 19.

Note that the bottom surface of the hole 18 is set in accordance with the usage limit when the carphone brush main body 11 is worn out.

The end of the detection lead wire 15 is connected to a suitable signal detection device.

The carphone brush configured as described above is mounted, for example, on the brush holder of a DC motor (not shown), and the bottom surface 11a of the carphone brush main body 11 is pressed against the commutator surface of the motor, like a known brush. Ru.

When the carphone brush body 11 is not worn and can be used, the detection lead wire 15 is connected to the carbon brush body 11.
Since the core wire 16 is electrically insulated from the commutator, no electrical signal is generated in the core wire 16.

When the carbon brush body 11 wears down to the limit of its use,
The bottom of the hole 18 is broken, the folded part of the detection lead wire 15 is pressed against the surface of the commutator 20 as shown in FIG.
Destroyed as shown in the figure.

Therefore, at this folded portion, the exposed portion 21 of the core wire 16 comes into contact with the commutator 20, and a voltage from the commutator is obtained at the core wire 16.

By issuing an appropriate alarm based on this signal, wear of the carphone brush body 11 can be automatically detected.

As detailed above, this idea is to bend and embed an insulated wire into a hole at an appropriate depth from the top surface of the brush and fix it there, and the depth of the hole can be precisely machined during the drilling process. On the other hand, since the insulated wire can be inserted to the lower end of the hole, the wear limit position of the brush can be easily and accurately determined, and the problem of variation in the wear limit position for each brush can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an example of a conventional brush wear detection mechanism, Fig. 2 is a partial sectional view showing an embodiment of this invention, and Fig. 3 is a state of brush wear in the embodiment shown in Fig. 2. FIG. 4 is a diagram showing a broken state of the coating of the lead wire for wear detection in the embodiment of FIG. 2. 11...Carbon brush body, 14...
・Lead wire, 15...Lead wire for wear detection, 1
6...Core wire, 17...Insulation coating, 18
...hole.

Claims (1)

[Scope of utility model registration request] While fixing the lead wire to the upper end of the carbon brush body via a suitable fixing metal fitting, one end of the insulated wire is folded back into a hole drilled to a predetermined depth from the upper end surface of the carbon brush body. The electric wire is inserted and fixed so that the end reaches near the bottom of the hole, and the other end of the wire is led out from the carbon brush body, so that when the carbon brush body is used, the bottom surface of the hole is damaged due to wear of the carbon brush body. When the folded end of the electric wire comes into contact with the commutator or slip ring of a motor, the insulation coating of the electric wire is torn and the core wire of the electric wire is electrically connected to the commutator or slip ring. A brush wear detection device characterized in that an electric signal is obtained from the other end of the electric wire by contacting the wire.