JPH0126896Y2 - - Google Patents

Description

[Detailed description of the invention] In this invention, the armature, which is attached to the field core, which is a fixed member, is movable in the axial direction, and is in a braking state when it is separated from the field core due to spring pressure, and the armature is magnetically attracted to the field core. This relates to a negative actuation type electromagnetic brake in which a state where the brake is released is a brake release state.

Conventionally, this type of electromagnetic brake
In Japanese Patent Publication No. 73431, a "reverse action electromagnetic brake or clutch" was proposed.

In the above publication, a friction plate attached to a leaf spring concentrically attached to a rotating body to be braked is movable in the axial direction using a plurality of bolts parallel to the axis attached to the outer periphery of the field core as guides. An electromagnetic brake is described in which the braking state is achieved by pressing a mounting plate fixed to a rotating machine with spring pressure by means of a supported armature.

As is clear from the contents of the publication, the electromagnetic brake described in the above publication has a complex structure in which it is fixed to the free end armature of a leaf spring whose base is fixed to multiple bolts. Since the leaf spring field core is arranged outside the outer peripheral surface of the leaf spring field core, there is a problem in that this type of device has a large diameter.

This invention provides a negative actuation type electromagnetic brake that solves the above problem, and includes a field core with a built-in electromagnetic coil, an armature facing the front end surface of this field core, and this armature attached to the field core. In a negatively operated electromagnetic brake comprising a leaf spring movably supported in an axial direction and a spring pressing the armature against a rotating member to be braked, a base of the leaf spring is fixed to a recess formed in a front end surface of the field core. In addition, the present invention is characterized in that the free end portion is fixed to the side surface of the front end surface of the field core of the armature.

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

FIG. 1 shows a negative operation type electromagnetic brake of this invention in a vertical side view, and FIG. 2 shows a cross-sectional view taken along the line of FIG. 1 with some parts omitted. As shown in the drawing, the field core 1 which is a fixed member
has a built-in electromagnetic coil 2 and a recess 4 having a depth corresponding to the thickness of the leaf spring 3 on the front end surface.

The leaf spring 3 has a circular annular shape in this embodiment and has ears 3A as a base facing outward at three equal angular divisions.
It has a shape with .

The recess 4 is simply formed on the front end surface of the outer pole portion 1A of the field core 1 to correspond to the ear portion 3A of the leaf spring, but the inner diameter of the leaf spring 3 is the same as that of the inner pole portion 1B of the field core 1. Since the ear portions 3A are larger than the outer diameter of the field core 1, simply by fitting and fixing the ear portions 3A into these recesses 4, the ear portions 3A are stored without protruding from the front end surface of the field core 1.

In this embodiment, the leaf spring 3 is divided into three equal parts along the circumference, and an outwardly protruding ear part 3A is shown. , it goes without saying that they may be formed on the outer periphery of the leaf spring 3 at appropriate positions, for example, divided into two equal parts or four equal parts.

In the field core 1, an annular groove 5 is formed between the outer pole part 1A and the inner pole part 1B with the front surface open, and the electromagnetic coil 2 is mounted inside the annular groove 5.

Since the surface of the bobbin or the fixing resin layer of the electromagnetic coil 2 is located axially inward from the recess 4, the leaf spring 3 does not come into contact with the electromagnetic coil 2.

As a means for fixing the leaf spring 3 to the field core 1, in this embodiment, screws 8 are provided in each of the recesses 4, parallel to the axis, and screwed into screw holes 7 that correspond to the holes 6 provided in the ear portions 3A. , but may also be done by other means.

On the other hand, the armature 9, which can be magnetically attracted to the field core 1, is attached to the leaf spring 3 by a rivet 10 at three equally angularly divided positions on the back side.
The free end of is fixed.

The armature 9 is supported by the leaf spring 3 to enable frictional contact with the brake disc 11;
An annular facing 12 is attached to the surface of the armature 9 facing the brake disk 11.

The facing 12 is the brake disc 11
It may be provided on the side.

The brake disk 11 is supported by a hub 13 as a rotating member to be braked so as to be freely adjustable in position in the axial direction and to rotate integrally with the hub 13 .

The support of the brake disc 11 on the hub 13 is as follows:
A female threaded portion 15 formed on the inner circumference of the brake disc 11 is screwed into a male threaded portion 14 formed on the outer periphery of the large diameter portion 13A of the hub 13, and the support is determined by adjusting the screwing depth. , or by other means.

In this embodiment, as means for holding the position of the brake disc 11 in the axial direction, screws 18 are inserted into screw insertion holes 17 provided at a plurality of locations in the detent plate 16 fitted to the small diameter portion 13B of the hub 13.
By screwing into the screw hole 19 provided in the brake disc 11 and tightening it, the threads of the male threaded part 14 and the female threaded part 15 are brought into close contact with each other to prevent the brake disc 11 from moving. You can read it.

Between the back side along the inner edge of the armature 9 and the inward flange portion 1C provided on the rear inner circumferential surface of the inner pole portion 1B of the field core 1, the armature 9 has a pressure welding property to the brake disc 11. A compression coil spring 20 is interposed to provide the power.

The compression coil spring 20 may be replaced by a compression coil spring in which holes are provided at a plurality of locations in the outer pole portion 1A or the inner pole portion 1B of the field core 1, and one end thereof is inserted into these holes. Alternatively, it may be a spring provided so as to act on the armature 9 at the outer peripheral portion of the outer pole portion 1A.

In the figure, reference numeral 21 indicates a through hole formed in the armature 9 to avoid the head of the screw 8, and 23 indicates a through hole provided to avoid the head of a mounting bolt (not shown). 22 is a keyway for fixing the hub 13 to a braked shaft (not shown).

FIG. 3 shows an embodiment using two semicircular arc-shaped leaf springs 3', 3', which are a modification of the leaf spring, in a sectional view corresponding to FIG. 2. In this case, since the leaf spring 3' has the ear portion 3'A provided only at one location in the center of the outer edge of the arc, the recessed portions 4 are provided at two diametrically symmetrical locations of the outer pole portion 1A.

Further, the leaf spring 3' is attached to the armature 9 at two locations on both ends of the leaf spring 3'.

This embodiment is the same as the embodiment previously described with reference to FIGS. 1 and 2, except that two leaf springs 3' are used.

In the above embodiments, the reference numeral 24 shown in FIGS. 1 to 3 indicates a through hole formed in the field core 1 for inserting the mounting bolt.

In the negative actuation type electromagnetic brake of this invention having the above-mentioned configuration, when the armature 9 is excited by applying voltage to the electromagnetic coil 2, the armature 9 is magnetically attracted to the field core 1, as shown in FIG. , the armature 9 is separated from the brake disc 11, and the braking on the hub 13 is released.

A state in which no voltage is applied to the electromagnetic coil 2, that is,
In a normal state, the armature 9 is not energized, so it is pushed by the compression coil spring 20 and comes into frictional contact with the brake disc 11, thereby braking the hub 13.

The negative actuation type electromagnetic brake of this invention is an example of a spring in which an armature 9, which is attached to the field core 1 so as to be movable only in the axial direction via a leaf spring 3 or 3', is interposed between the field core 1 and the armature 9. As a result, the structure is significantly reduced because the hub 13, which is always in pressure contact with the brake disc 11 by the compression coil spring 20 and is attached so as to rotate integrally with the rotating shaft of the equipment that is the rotating member to be braked, is used. It is simple and can be obtained at low cost, and in particular, there is no noise caused by collision of spline teeth during braking or torque fluctuation, and it has the advantage of being optimally used for brakes of industrial robots, etc.

Further, a leaf spring 3 or 3' is provided for movably supporting the armature 9 on the field core 1 in the axial direction.
Since the base of the field core 1 is fixed to the recess 4 formed on the front end surface of the field core 1, the diameter of this type of device can be reduced, and the outer pole of the field core 1, which forms part of the magnetic circuit of the electromagnetic coil 2, There is also an advantage that no gap is formed between the portion 1A and the armature 9 in the excited state, and magnetic resistance in the magnetic circuit can be suppressed.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional side view showing an embodiment of the negative actuation type electromagnetic brake of this invention, Fig. 2 is a sectional view taken along the line of Fig. 1, and Fig. 3 is a diagram showing an embodiment using a modified leaf spring. It is a sectional view equivalent to Figure 2. In the drawings, 1... field core, 2... electromagnetic coil,
3, 3'...plate spring, 3A, 3'A...ear, 4...
... recess, 8... screw, 9... armature, 10
... Rivets, 11 ... Brake disc, 12
... Facing, 13 ... Hub, 14 ... Male thread part, 15 ... Female thread part, 16 ... Stopping plate,
18...screw, 20...compression coil spring.

Claims (1)

[Scope of utility model registration request] A field core with a built-in electromagnetic coil, an armature facing the front end surface of the field core, a leaf spring that supports the armature movably in the axial direction on the field core, and presses the armature against a rotating member to be braked. In the negative actuating electromagnetic brake having a spring, a base of the leaf spring is fixed to a recess formed in a front end surface of the field core, and a free end is fixed to a side surface of the front end surface of the field core of the armature. A negative actuation type electromagnetic brake characterized by: