JPH0125787Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic brake, and particularly to an electromagnetic brake that uses magnetic force generated by energizing a coil to attract a plate and stop the rotation of a shaft.

In the conventional electromagnetic brake, as shown in FIG. 1, a shaft 1 is connected to a support shaft 3 via a one-way clutch 2, and the support shaft 3 is fixed to a plate 5 by a rod 4. Further, the support shaft 3 is rotatably disposed on the yoke 7 via a bearing 6. This yoke 7 is divided into two parts, a second yoke 9, and a second yoke 9 in order to narrowly attach the shielding plate 8. A bobbin 11 around which a coil 10 is wound is disposed within the yoke 7.
The coil 10 is connected to a terminal 11 and molded with a resin mold 12, and then a lead wire 13
is connected to. Further, one end of a leaf spring 14 is fixed to the plate 5, and the other end is fixed to the shaft 1. However, the shaft 1 has a leaf spring 14.
It can be rotated freely against the

The electromagnetic brake with the above configuration is, for example, a vehicle safety brake, that is, when the brake pedal is depressed for a certain period of time or more, the electromagnetic brake fixes the brake pedal in that position and maintains the braking state. It is used in a device that automatically releases the brake by detecting the movement of the vehicle into a running state (for example, depression of the accelerator pedal). In this case, an electric circuit is provided that connects the shaft 1 to the brake pedal via a link and that energizes the coil 10 after a certain period of time has passed after the brake pedal is depressed. When the brake pedal is depressed and a certain period of time has elapsed, the coil 10 is energized and a magnetic force is generated, which attracts the plate 5 against the leaf spring 14, thereby fixing it to the upper surface of the yoke 7.
Therefore, since the support shaft 3 is fixed,
Shaft 1 can only rotate in one direction (in this case, the direction in which the brake pedal is depressed) due to the action of one-way clutch 2.
is fixed in that position. After that, when the power to the coil 10 is turned off, the plate 5 is separated from the yoke 7 by the leaf spring 14, so the shaft 1 can rotate together with the support shaft 3, and the spring force of the return spring attached to the brake pedal allows the shaft 1 to rotate. Shaft 1 returns together with the brake pedal.

However, with this electromagnetic brake, the yoke is
The bobbin and coil were press-fitted because the shielding plate made of non-magnetic material was sandwiched between the
The disadvantage was that processing such as resin molding and brazing the divided yokes was difficult. The shielding plate made of non-magnetic material is essential for this type of electromagnetic brake in order to prevent the plate from disconnecting from the yoke due to residual magnetism that occurs when the power to the coil is turned off. It is.

The object of the present invention is to form the yoke integrally by providing the shielding plate on the plate. To this end, in the present invention, a shielding plate made of a non-magnetic material is inserted into the plate, and an annular groove is provided to form an air gap in the coil side portion of the plate that is divided by the insertion of the shielding plate. , the yoke is integrally formed so that the plate itself blocks magnetism.

Therefore, since the yoke can be integrally formed, processing becomes easy and the desired purpose can be achieved. Also,
In the present invention, since the shielding plate is inserted between the divided plates, wear due to friction can be prevented compared to when the shielding plate is attached directly to the bottom surface of the plate (in the embodiment of the present invention described later). Since the shielding plate is made of stainless steel or copper, it has the disadvantage of being subject to severe wear.) For this purpose, in this invention,
Among the divided plates, an annular groove forming an air gap is provided on the coil-side plate so that the magnetic force always passes across the shielding plate and through the inside of the plate, thereby ensuring the effectiveness of the shielding plate. ing.

Hereinafter, an embodiment of the electromagnetic brake according to the present invention will be explained with reference to FIG. Here, the parts given the same numbers as in FIG. 1 have the same configurations and functions, so their explanations will be omitted here. In this embodiment, the coil 10 and the bobbin 11 are arranged in an integrally formed yoke 20 and molded with a resin mold 12. In addition, the plates include a first plate 21, a second plate 22, and a third plate 2.
It is divided into three parts. A shielding plate 24 is inserted between the first plate 21, the second plate 22, and the third plate 23, and these include rivets 25 that connect the first plate 21, the shielding plate 24, and the second plate 22. and rivets 2 that connect the first plate 21, the shielding plate 24, and the third plate 23.
It is fixed by 6. Also, the second plate 2
2 and the third plate 23 is provided with an annular groove 27 forming an air gap.

With this configuration, when the coil 10 is energized,
A magnetic force is generated in the yoke 20, and this magnetic force
0, third plate 23, first plate 21, second
A magnetic circuit is formed with the plate 22 and the yoke 20. At this time, the second plate 22 and the third plate 2
3 has an air gap created by the annular groove 27, so that the magnetism forms the above magnetic circuit. Next, when the power to the coil 10 is turned off, the shielding plate 2
4 interrupts the magnetic circuit, and each plate 21, 22, 23 is immediately separated from the yoke 20.

The operation of the electromagnetic brake according to the present invention when applied to a safety brake is similar to that of the conventional electromagnetic brake described above.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional electromagnetic brake, and FIG. 2 is a sectional view of an embodiment of the electromagnetic brake according to the present invention. 1...Shaft, 2...One-way clutch, 3...Support shaft, 10...Coil,
11...Bobbin, 20...Yoke, 21...1st
Plate, 22...Second plate, 23...Third
Plate, 24... Shielding plate, 27... Annular groove.

Claims (1)

[Scope of utility model registration request] In an electromagnetic brake that attracts a plate to stop rotation of the shaft using magnetic force generated by energizing a coil, a shielding plate made of a non-magnetic material is inserted into the plate, and the plate is divided by the insertion of the shielding plate. An electromagnetic brake in which an annular groove forming an air gap is provided on the coil side plate of the plate.