JPH0129291Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a negatively actuated electromagnetic brake that prevents a rotating member to be braked from idling due to inertia or maintains a stationary state.

As shown in FIG. 1, an example of which is shown in a longitudinal sectional side view, the negative actuation type electromagnetic brake has a hub 2 that rotates together with a shaft 1 as a rotating member to be braked. The armature 5 receives the elastic pressing force of the compression coil spring 4, and the friction plate 3 is supported integrally and movably in the axial direction by the armature 5.
The shaft 1 is braked by clamping the field core 6, which is obtained by turning or forging a magnetic material, with a fixed pressure receiving plate 7, which is opposed to the field core 6 with a predetermined distance therebetween. Only when releasing the magnetic field core 6, a required voltage is applied to the electromagnetic coil 8 built in the field core 6, and the armature 5 directly facing the field core 6 with a gap g is magnetically attracted to the field core 6.

This type of conventional negative actuating electromagnetic brake has a field core obtained by turning or forging a steel material, resulting in a large weight. Bolt mounting space is also required, making it unavoidable to increase the size.
Assembling the electromagnetic coil took time and effort, resulting in high costs.

Based on the above-mentioned viewpoint, this invention provides a negative-actuation type electromagnetic brake that solves the above-mentioned problems.In a negative-actuation type electromagnetic brake equipped with a field core with a built-in electromagnetic coil, the field core is made of a press-molded steel plate. A bobbin with an electromagnetic coil wound therein is fitted onto the outer diameter surface of the inner pole of the field core, while an outward facing bobbin, which is a press-formed steel plate and which fixes the bobbin to prevent it from coming out, is fitted onto the inner diameter surface of the inner pole. The structure is made by fitting a pipe member as a press-formed product, which has a bent part and an inward bent part to receive one end of a compression coil spring for braking, to achieve smaller size, lighter weight, and lower cost. The points are distinctive.

Next, the negative actuation type electromagnetic brake of this invention will be explained by way of examples with reference to the drawings.

FIG. 2 shows an embodiment of the negative actuation type electromagnetic brake of this invention in a longitudinal sectional side view. As shown in the drawing, the negative actuation type electromagnetic brake of this embodiment is
A bobbin 12 made of plastic or rubber and a tube member 13 serving as a spring holder are fitted into a field core 6' of a press-formed product manufactured by pressing a steel plate, for example.

The field core 6' has an inner pole 6'A and an outer pole 6'B.
It is an annular member formed as a double annular wall, and has an outwardly bent portion 6'C at the mouth edge of the outer pole 6'B.

The bent portion 6'C may be a flange extending around the entire circumference, or may be a partially protruding ear portion.

Further, the pressure receiving plate 7', which is a press-formed product, has a cut-out portion 14 having a bent portion 14A that abuts and fixes (for example, fixes by spot welding) to the bent portion 6'C.
It is an annular plate having holes 15 for passing bolts (not shown) used for attachment to a device frame (not shown) or the like.

A gap g between the field core 6' and the armature 5' is maintained by the cut-out portion 14.

The armature 5' is also a press-formed product of a carbon steel plate, and has notches 16 that engage with the notches 14 at a plurality of predetermined locations corresponding to the notches 14.
A friction plate 3 is spline-fitted to a hub 2 fixed to a rotary shaft to be braked (not shown) and supported so as to be integrally rotatable and movable in the axial direction. The friction plate 3 is a flat plate-like member that can be freely pressed against a pressure receiving plate 7'.

The tube member 13 is connected to the inner pole 6'A of the field core 6'.
A circumferential body portion 13A that tightly fits into the inner peripheral surface of the inner pole 6′A, an outwardly bent portion 13B that contacts the front end surface of the inner pole 6′A and is bent toward the outer pole 6′B, and an inner portion that serves as a spring receiving portion. and a bent portion 13c in the direction of the bending portion 1.
3c, the other end of the braking compression coil spring 4 whose one end is in contact with the armature 5' is brought into contact.

The electromagnetic coil 8 built into the field core 6' is
It is wound around the bobbin 12 which is tightly fitted to the outer diameter surface of the inner pole 6'A, and is manufactured in advance as one piece.

Note that the bobbin 12 has a tube member 13 on the front wall portion 12A.
It is prevented from coming off by bringing the bent portion 13B into contact with it.

In the negative-actuation type electromagnetic brake of this invention having the above-mentioned configuration, like the conventional negative-action type electromagnetic brake, the armature 5', which is constantly receiving the pressing force of the compression coil spring 4, moves the friction plate 3 to the pressure-receiving plate 7'. The rotation of the hub 2 is stopped by pressing the armature 5' toward the field core 6' by applying a voltage to the electromagnetic coil 8, thereby releasing the friction plate 3.
Free hub 2.

The field core 6' manufactured by pressing a steel plate has approximately uniform thickness at each part, but the tube member 13
By fitting the inner pole 6'A, the wall thickness of the inner pole 6'A becomes 2.
This results in a field core having an inner pole through which a sufficient amount of magnetic flux can pass through to strongly magnetically attract the armature 5'.

Moreover, since the bobbin 12 can be fixed to prevent it from coming off by fitting the pipe member 13 made of a press-formed steel plate, it does not take much time to assemble it.

Furthermore, the field core 6' and the tube member 13, which are press-formed steel plates, are significantly lighter than conventional machined or forged products.

As is clear from the above explanation, the negative actuation type electromagnetic brake of this invention has a field core, which is a pressed product of a steel plate, and a pipe member, which is also a pressed product of a steel plate, and which serves as a spring holder, is fitted into the field core. Therefore, it is possible to make the field core smaller and lighter, and only the thickness of the inner pole can be increased.
It has excellent advantages such as being able to prevent the bobbin from coming off with the tubular member and greatly reducing processing and assembly costs.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing a conventional negative action electromagnetic brake, and FIG. 2 is a longitudinal side view showing an embodiment of the negative action electromagnetic brake of this invention. In the drawings, 2...hub, 3...friction plate, 4...compression coil spring, 5, 5'...armature, 6'...armature, 6'A...inner pole, 6'B...outer pole , 6'c
...Bending portion, 7, 7'...Pressure plate, 8...Electromagnetic coil, 12...Bobbin, 12A...Front wall portion, 13
... Pipe member, 13A ... Peripheral body part, 13B, 13C
...Bending part.

Claims (1)

[Scope of utility model registration request] In a negative actuation type electromagnetic brake equipped with a field core with a built-in electromagnetic coil, the field core is a press-molded product of a steel plate, and a bobbin with the electromagnetic coil wound therein is fitted onto the outer diameter surface of the inner pole of the field core. A tube member, which is a press-molded steel plate, and has an outward bent portion for fixing the bobbin to prevent it from coming off, and an inward bent portion for receiving one end of a braking compression coil spring, on the inner diameter surface of the inner pole. Negative action type electromagnetic brake that is fitted with