JP2562030Y2 - Electromagnetic brake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic brake in which an armature is moved forward and backward by a spring force of a braking spring and a magnetic attraction force of an electromagnetic coil to brake rotation and release braking.

[0002]

2. Description of the Related Art As one kind of such an electromagnetic brake,
For example, as disclosed in JP-A-63-115920, there is known an electromagnetic brake in which a brake shoe is provided and a rolling element such as a ball or a roller is interposed between the brake shoe and an armature. . This electromagnetic brake is provided with a field core fixed to a fixed portion such as a motor and having an electromagnetic coil provided therein, and an armature capable of moving back and forth in the axial direction with a plane facing a magnetic pole surface of the field core. The armature is urged in a direction away from the field core by a braking spring mounted in a recess of the field core.

When the electromagnetic coil is not excited,
A predetermined gap is formed between the magnetic pole surface of the field core and the plane of the armature by the spring force of the braking spring, and when the electromagnetic coil is excited, the armature resists the magnetic force of the field core against the spring force of the braking spring. It is configured to be magnetically attracted to the surface.

Further, a brake drum as a member to be braked, which is formed in a dish shape, is key-fixed to a rotating shaft of the motor which penetrates through the inner hole of the field core and the inner hole of the armature. The cylindrical portion covers the outer peripheral surface of the field core and the armature via a space. In the space, a plurality of arc-shaped brake shoes are held by arc-shaped leaf springs having both ends fixed to the outer peripheral surface of the field core, and the outer peripheral surface is fixed to each of the brake shoes. An arcuate lining facing the inner peripheral surface of the brake drum is housed.

Further, a plurality of balls are interposed between a tapered surface formed on the outer peripheral surface of the armature and a bent piece of a leaf spring bent substantially parallel to the tapered surface. Is equipped.

[0006] With this configuration, when the electromagnetic coil is not excited, the armature is separated from the magnetic pole surface of the field core by the spring force of the braking spring, and at this time, the ball moves on the tapered surface of the armature. Since the brake shoe is pressed against the inner peripheral surface of the cylindrical portion of the brake drum against the spring force of the leaf spring by the action, the rotation of the rotating shaft is braked via the brake drum.

When the electromagnetic coil is excited from this state to generate magnetic flux, the armature is attracted to the magnetic pole surface of the field core against the spring force of the braking spring, and the ball is released from being held by the inclined surface of the leaf spring. As a result, the diameter of the spring is reduced by the elastic return of the plate spring, the pressure contact of the brake shoe against the inner peripheral surface of the cylindrical portion of the brake drum is released, and the rotation shaft integrated with the brake drum can rotate.

[0008]

However, in the conventional electromagnetic brake configured as described above, since the rolling elements move along the tapered surface of the armature during braking, the rolling elements are inclined, in other words. If the armature moves in the radial direction while moving in the moving direction,
The arcuate leaf spring or brake shoe is pushed in the direction of movement of the armature by the spring force of the brake spring.

For this reason, there arises a problem that the leaf spring is twisted or a spring force of the braking spring is applied to the rotating shaft via the brake shoe and the brake drum. In order to solve such problems and increase the durability of the device, the rigidity of the brake shoe supporting leaf spring may be increased. However,
In such a case, the spring force of the brake spring and the magnetic attraction force of the electromagnetic coil must be set large, and the device cannot be provided at a large size and at low cost.

This invention prevents the torsion of the leaf spring during braking and the spring force of the braking spring acting on the rotating shaft, and ensures the durability of the leaf spring and the reliability of quality for manufacturers of motors and the like to which the electromagnetic brake is mounted. The purpose is to increase. Also, by simplifying the shape of the leaf spring and the shape of the armature,
An object is to provide an electromagnetic brake at low cost.

[0011]

In order to achieve such an object, the present invention provides a field core having an electromagnetic coil therein, a disk portion facing the field core, and
Formed integrally with the outer periphery of the disk part at circumferential intervals
An axial projection and a radially inner side of the projection
Tapered surface, and an axis line
An armature that is only movably supported in a direction, the
Armature always attached away from field core
A braking spring, a braked member having a cylindrical portion disposed coaxially with the armature and the field core, and a plurality of brake springs arranged along the outer peripheral surface of the cylindrical portion of the braked member, each of which is individually configured by a leaf spring. A brake shoe elastically supported by a field core, and a tapered surface of the armature
And a rolling element interposed between the brake shoe and the brake shoe.
The leaf spring fixed to the brake shoe is
Drilled at the joint between the armature disk and the protrusion
And fixed to the field core through the through hole .

[0012] Further, to the field core of the leaf spring.
In the fixing position, there is a through hole having an engagement side orthogonal to the axis.
A hole for the adjusting body to be inserted into this through hole is provided.
The mating side and the engaging side of the leaf spring are brought into contact with each other,
The screw was attached to the field core.
Features .

[0013]

When the electromagnetic coil is not energized, the armature is separated from the magnetic pole surface of the field core by the spring force of the braking spring, and at this time, the rolling element uses the taper surface provided on the armature to apply the brake shoe to the leaf spring. The rotation of the rotating shaft is braked through these members because the cylinder is pressed against the cylinder portion against the force. Further, when the electromagnetic coil is excited from this state to generate magnetic flux, the armature is attracted to the magnetic pole surface of the field core against the spring force of the braking spring, and the rolling element is released from the tapered surface of the armature. The spring is elastically restored, the pressure contact of the brake shoe against the cylindrical portion of the member to be braked is released, and the rotation shaft integrated with the member to be braked can rotate.

[0014]

1 to 8 show an embodiment of an electromagnetic brake according to the present invention. FIG. 1 is a front view of the electromagnetic brake, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. Is a plan view of the armature, FIG. 4 is a sectional view of the armature, FIG. 5 is a partial perspective view of the armature, FIG. 6 is a front view of the brake shoe, FIG. 7 is a side view of the brake shoe, and FIG. is there. Hereinafter, a detailed description will be given based on these drawings.

The electromagnetic brake 1 is mounted on a motor 2 which is a driving source of an industrial robot, and a field core 4 having an electromagnetic coil 3 provided therein is fixed to a bracket of the motor 2 by screws. The field core 4 is a clapper-type electromagnet, and is formed in an annular groove 4a in which the electromagnetic coil 3 is insulated and fixed by resin with an opening in the axial direction, and a cylindrical outer pole portion serving as an outer peripheral wall of the annular groove 4a. Spring hole 4b,
A concave groove 4c to which a leaf spring 9 to be described later is fixed by a screw, a spring pin press-fitting fixing hole (not shown) formed in the magnetic pole surface of the outer pole portion, and a manual releasing screw hole 4d are formed. . Reference numeral 4e is a mounting hole into which a mounting bolt is inserted. Also, a spring hole 4b, a concave groove 4c, a spring pin press-fit fixing hole, a manual release screw hole 4d, and a mounting hole 4d are provided.
e are all individually formed at positions that divide the circumferential direction of the field core 4 into three equal parts with different phases.

A disc-shaped armature 5 is supported on the field core 4 by a spring pin 6 so that a predetermined gap is formed when the electromagnetic coil 3 is not excited. The armature 5 can move forward and backward in the axial direction by opposing the magnetic pole surface of the field core 4 by the spring force of the braking spring 7 mounted in the spring hole 4b of the field core 4 and the magnetic attraction force of the electromagnetic coil 3.

The armature 5 has a disk portion 5 having an inner hole.
a and an axially projecting portion 5b integrally formed by pressing at a position dividing the outer periphery of the disk portion 5a into three equal parts. As shown in a perspective view in FIG. A concave groove 5c in which a rolling element 12 to be described later is mounted is formed on the inner surface of the portion 5b, and the bottom of the concave groove 5c is a tapered surface 5d that becomes deeper as the distance from the field core 4 increases. Further, the armature 5 is provided with a through hole 5e at a connecting portion between the disk portion 5a and the protruding portion 5b.

Each of the brake shoes 8 is disposed with a space in a radially inner side of the protrusion 5 b of the armature 5, and the brake shoes 8 are elastically supported by the field core 4 by a leaf spring 9. The brake shoe 8 has an L-shaped cross section, and a rectangular plate 10 is fixed to a right-angled inner wall surface with rivets to increase rigidity of the wall portion. Also, the other wall surface is screwed with an end portion of a leaf spring 9 which is similarly overlapped over the entire surface in order to increase the rigidity of the wall portion. On the other hand, a lining 11 having an arc-shaped friction surface is fixed to the outer wall surface on the opposite side where the end of the leaf spring 9 is fixed.

As shown in FIG. 8, the leaf spring 9 has a pair of cutouts 9a formed in a rectangular plate member.
A bent portion 9b having a reduced rigidity is formed near the fixed position to the side, and a screw hole located on two straight lines is formed. The leaf spring 9 fixed to the brake shoe 8 passes through the through hole 5e of the armature 5, is engaged with the concave groove 4c of the field core 4, and is fixed with a screw.
Here, the fixing position of the leaf spring 9 to the brake shoe 8 and the field core 4 is configured on a straight line substantially parallel to the axis.

The rectangular plate 10 fixed to the brake shoe 8
A cylindrical roller 12 as a rolling element is provided in a space formed by the end of the leaf spring 9 and the tapered surface 5 d of the armature 5.
Are individually interposed. Further, the lining 11 fixed to the brake shoe 8 is structured so as to come into contact with and separate from the outer peripheral surface of the cylindrical portion of the brake wheel 13 as a member to be braked, which is mounted on the rotating shaft 2a of the motor 2.

The electromagnetic brake 1 having the above structure
In the non-excited state in which the electromagnetic coil 3 is not energized as shown in FIG. 2, the armature 5 is separated from the magnetic pole surface of the field core 4 by the spring force of the braking spring 7, and the roller 12 is fixed to the tapered surface of the armature 5. 5d, the brake shoe 8 is moved against the brake wheel 1 against the spring force of the leaf spring 9.
3, the rotation of the rotating shaft 2 a is braked via the brake shoe 8. Further, when the electromagnetic coil 3 is excited from this state to generate a magnetic flux, the armature 5 resists the spring force of the braking spring 7 and
And the roller 12 is released from the tapered surface 5d of the armature 5, the plate spring 9 elastically returns, and the pressure contact of the brake shoe 8 against the cylindrical portion of the brake wheel 13 is released. The integral rotating shaft 2a becomes rotatable.

Next, an electromagnetic brake according to another embodiment of the present invention will be described with reference to FIGS. 9 is an upper half sectional view of an electromagnetic brake, FIG. 10 is an enlarged sectional view of a fixed portion of a leaf spring, and FIG.
FIG. The electromagnetic brake 14 shown in these drawings has a structure capable of adjusting the gap size when the lining 11 and the brake wheel 13 are excited, in other words, adjusting the gap size when the field core 4 and the armature 5 are not excited. I have.

A leaf spring 1 for elastically supporting the brake shoe 8
5 has a through hole 1 having an engagement side 15a orthogonal to the axis.
5b, and a head-shaped adjusting body 16 having an engaging side 16a joined to the engaging side 15a is fitted into the through hole 15b.

Then, with the engaging side 15a of the leaf spring 15 and the engaging side 16a of the adjusting body 16 in contact with each other, the adjusting body 16
Is fixed to the field core 4 via a shim 18 by a screw 17. With such a structure, the size of the gap between the lining 11 and the brake wheel 13 can be finely adjusted by the size of the engagement side 16a of the adjusting body 16. In this embodiment, only one side of the engagement side 16a is formed on the adjusting body 16, but the plurality of engagement sides 1 having a polygonal shape and different dimensions are formed.
The adjusting body 16 having 6a may be used. The above theory
In the description, the groove 4c is formed in the field core 4 and the leaf springs 9 and 15 are fixed in the groove 4c. However, the design of such a detailed structure can be changed as appropriate.

[0025]

As described above, according to the present invention, a leaf spring for elastically supporting a brake shoe on a field core is provided in an internal tightening type electromagnetic brake in which a rolling element is interposed between a tapered surface of an armature and a brake shoe. It is arranged in the axial direction, and the fixed position of the leaf spring to the field core and the fixed position to the brake shoe are on a straight line substantially parallel to the axis, so that the torsion of the leaf spring during braking and the braking acting on the rotating shaft The spring force of the spring can be prevented. Further, the shape and mounting structure of the leaf spring are simplified, and the electromagnetic brake can be provided at low cost.

An axially projecting portion having a tapered surface is integrally formed on the armature, and the armature is formed integrally with the armature.
A through hole is drilled at the joint between the disc and the protruding part, and a leaf spring is inserted through the through hole to provide a structure .
Provide a tapered surface on the outer periphery of the mature material, outside the tapered surface
Compared to an externally-clamped electromagnetic brake with a brake shoe
In addition, the tapered surface of the armature and the brake shoe can be radially opposed to each other without increasing the shape of the brake shoe. Therefore, the size and weight of the device can be reduced. Furthermore, a tapered surface on the inner circumference of the armature
The brake shoe was constructed inside the tapered surface
Larger brake shoe shape compared to internal tightening type electromagnetic brake
It has a large braking force despite its small size and light weight.
Can be

Further, since the leaf spring is fixed to the field core via the adjusting member, the air gap can be easily adjusted and the electromagnetic brake can be operated stably, so that the reliability in quality can be improved. .

[Brief description of the drawings]

FIG. 1 is a front view of an electromagnetic brake according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of the armature.

FIG. 4 is a sectional view of an armature.

FIG. 5 is a partial perspective view of the armature.

FIG. 6 is a front view of the brake shoe.

FIG. 7 is a side view of the brake shoe.

FIG. 8 is a front view of a leaf spring.

FIG. 9 is a top half sectional view of an electromagnetic brake according to another embodiment of the present invention.

FIG. 10 is an enlarged sectional view of a fixed portion of a leaf spring.

FIG. 11 is a view taken along line BB of FIG. 10;

[Explanation of symbols]

 Reference Signs List 3 electromagnetic coil 4 field core 5 armature 7 brake spring 8 brake shoe 9 leaf spring 12 roller 16 adjuster

Claims (2)

(57) [Scope of request for utility model registration] 1. A field core in which an electromagnetic coil is provided, a disk portion facing the field core, and the disk
Axial direction integrally formed on the outer circumference of the part at circumferential intervals
And a tape formed radially inside the projection.
And a field surface is provided on the field core in the axial direction.
Armature supported only to advance and retreat and this armature
Always biases the tur away from the field core
Wherein the field core and the braking spring, the braked member with the armature and the disposed field core coaxially cylindrical portion, by the individual to the leaf spring are a plurality arranged along a cylindrical outer peripheral surface of the braked member A brake shoe elastically supported on the tapered surface of the armature;
A rolling element interposed between the brake shoe and
The leaf spring fixed to the brake shoe is
Penetration drilled at the joint between the mature disc and the protrusion
An electromagnetic brake, wherein the electromagnetic brake is fixed to the field core through a through hole . 2. A method for fixing the leaf spring to the field core.
In the fixed position, a through hole having an engagement side perpendicular to the axis is drilled.
And an engagement side of the adjusting body inserted into the through hole.
And the engagement side of the leaf spring, and
The adjusting body is screwed to the field core.
The electromagnetic brake according to claim 1, wherein