JP2533565Y2 - Electromagnetic brake - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a spring force of a braking spring,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic brake that brakes rotation and releases braking by moving an armature forward and backward with a magnetic attraction force of an electromagnetic coil.

[0002]

2. Description of the Related Art Conventional electromagnetic brakes of this type include:
For example, there are those disclosed in JP-A-63-115920 or Japanese Utility Model Application No. 2-108468. Each of these is a non-excited operation type electromagnetic brake attached to the end of the motor.The armature supported by the field core so as to be movable in the axial direction is separated from the field core by the braking spring when not energized, and the field spring by the leaf spring. The brake shoe elastically supported by the core is configured to be pressed in the radial direction (toward the peripheral surface of the brake drum or the brake wheel). Further, a brake drum or a brake wheel as a brake member is positioned on the opposite side of the armature from the field core, and is coupled to a shaft end of a motor shaft that rotates through the field core and the armature.

In order to change the axial movement of the armature to the radial movement and press the brake shoe, an inclined cam surface which is gradually inclined toward the axial center as the armature is separated from the field core, and this inclined cam surface Rolling elements such as balls and rollers that roll along the road have been used. In the electromagnetic brake disclosed in JP-A-63-115920, the inclined cam surface is provided on the armature side so as to face radially outward, and the rolling elements are disposed radially outward from the inclined cam surface. Between the brake shoe supporting leaf springs. In this electromagnetic brake, a bottomed cylindrical brake drum having an inner peripheral surface serving as a friction surface was used as a brake member, and a brake shoe and an armature were arranged inside the cylindrical portion. And, in order to prevent the rolling element from falling off, the plate spring is provided with a flange formed so as to be opposed to the inclined cam surface. That is, in this electromagnetic brake, the rolling element pushes the leaf spring and the brake shoe outward in the radial direction when the armature separates from the field core during non-excitation, and is braked. Jpn.
In the electromagnetic brake disclosed in No. 8, an inclined cam surface is provided on an annular side plate fixed on the opposite side of the armature from the field core. The inclined cam surface is provided on the inner peripheral portion of the side plate so as to face radially inward, and the rolling element includes a brake shoe supporting leaf spring disposed on the inner peripheral side of the side plate and the inclined cam. It was interposed between the face and the armature. In addition,
In this electromagnetic brake, a brake wheel having an outer peripheral surface serving as a friction surface is used as a brake member, and a brake shoe is positioned radially outside the brake wheel. That is, in this electromagnetic brake, the rolling element pushes the leaf spring and the brake shoe radially inward when the armature separates from the field core during non-excitation, and is braked.

[0004]

However, in the conventional electromagnetic brake configured as described above, since the rolling element moves along the inclined cam surface during braking, the rolling element is inclined, in other words, As the armature moves in the radial direction while moving in the moving direction of the armature, the leaf spring and the brake member are pushed in the moving direction of the armature by the spring force of the braking spring. For this reason, there arises a problem that the leaf spring is twisted or a spring force of the braking spring directed in the axial direction to the motor shaft is applied via the braking member.
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 braking spring and the magnetic attraction force of the electromagnetic coil must be set large, and the device becomes large.

[0005]

In the electromagnetic brake according to the present invention, an inclined cam surface is formed on an armature, and a flat stopper surface extending radially from the armature on a side opposite to the field core has an armature. The side plate formed on the side is fixed, and the rolling element is brought into contact with the stopper surface and interposed between the inclined cam surface and the brake shoe supporting leaf spring.

[0006]

The axial force when the rolling element is pressed by the braking operation of the armature is received by the side plate, and only the radial force is applied to the brake shoe supporting leaf spring.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a front view of the electromagnetic brake according to the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In these figures, reference numeral 1 denotes a motor shown as an example of a device. An annular field core 2 is fixed to a fixed portion of the motor 1.
In the annular groove 2a, an electromagnetic coil 4 formed in an annular shape and connected to a power supply via a lead wire 3 is housed. A collar 5 and a side plate 11, which will be described later, are fixed with bolts 6 at locations where the outer peripheral portion of the field core 2 is equally divided in the circumferential direction, and an armature 7 formed in an annular shape is attached to the field core 2. Adjacent and supported by the collar 5, it is provided so as to be slightly movable in the axial direction. Also,
A braking spring 8 for urging the armature 7 in a direction for separating the armature 7 from the magnetic pole surface 2c of the field core 2 is provided in each of the spring holes 2b provided at a position where the outer peripheral portion of the field core 2 is equally divided in the circumferential direction. Each is loaded.

Thus, when the electromagnetic coil 4 is excited, the armature 7 is attracted to the magnetic attraction surface 2c of the field core 2 against the spring force of the braking spring 8, and
When the excitation of the electromagnetic coil 4 is released from this state, the armature 7 is separated from the magnetic pole surface 2c of the field core 2 by the spring force of the braking spring 8 to form a predetermined gap indicated by reference symbol G in the figure. Have been.

Reference numeral 9 denotes a motor shaft serving as a rotating shaft of the motor 1, which is provided through the inner hole of the field core 2 and the armature 7, and a brake wheel 10 serving as a brake member is provided on the motor shaft 9. Are integrated and supported by fixing the hub 10a with the key 9a. The brake wheel 10 is integrally formed with a hub 10a and a dish-shaped portion having an annular flange 10b extending in the axial direction, and the annular side plate 11 is provided outside the flange 10b. Armature 7
And is fixed to the field core 2 with bolts 6. The side plate 11
Surface (stopper surface) 11a on the armature 7 side
Are flat surfaces extending in the radial direction. In the annular space surrounded by the flange 10b, the armature 7, and the side plate 11 of the brake wheel 10, a braking portion indicated by reference numeral 12 as a whole divides the armature 7 into a plurality of pieces in the circumferential direction. It is provided at a position where it is divided into three. That is, a cam member 15 for holding the ball 13 as a rolling element in the inclined groove 14 is fixed by welding or the like at a position where the armature 7 is divided into three equal parts. , The cam member 1
A leaf spring 16 extending on both sides in the circumferential direction around the center 5 is provided with one end fixed by screws 17. The leaf spring 16 is urged radially outward of the armature 7. A brake shoe 18 is fixed to a center portion of the leaf spring 16 in the width direction, that is, a portion corresponding to the cam member 15, and an arc surface of the brake lining 19 fixed to the brake shoe 18 is an outer peripheral surface of the flange 10b. Is confronted with.

The inclined groove 14 of the cam member 15 is opened radially inward of the armature 7, and the bottom surface 14 a of the inclined groove 14, which is an inclined cam surface, gradually extends radially outward as the distance from the armature 7 increases. It is inclined linearly to be present. And the ball 13
It is interposed between the bottom surface 14a, the armature-side surface 11a of the side plate 11, and the leaf spring 16.
Reference numeral 20 denotes a manual release screw hole provided in the side plate.

Next, the operation of the electromagnetic brake configured as described above will be described. When the armature 7 is attracted to the magnetic pole surface 2c of the field core 2 from the state shown in the drawing, the ball 13 is released from being sandwiched between the leaf spring 16 and the bottom surface 14a of the inclined groove 14. Then, the brake shoe 18 is connected to the leaf spring 16.
When the brake wheel 10 moves in the radial direction due to the elastic return of the brake wheel 10 and the braking of the brake wheel 10 by the brake lining 19 is released, the motor shaft 9 integrated with the brake wheel 10 can rotate. In this state, when the switch for driving the motor 1 is turned off and the excitation of the electromagnetic coil 4 is released, the armature 7 is actuated by the spring force of the braking spring 8 so that the field core 2
Away from the magnetic pole surface 2c of the
Moves radially inward against the spring force of the leaf spring 16.
At this time, the ball 13 moves radially inward along the armature side surface 11a of the side plate 11. Then, the brake lining 19 is pressed against the outer peripheral surface of the flange 10b of the brake wheel 10 to brake the rotation of the brake wheel 10, and the motor shaft 9 integrated with the brake wheel 10 is braked and suddenly stopped. Therefore, when the ball 13 is pressed by the braking operation of the armature 7, the component force in the axial direction is reduced by the side plate 11.
And only a component force in the radial direction is applied to the leaf spring 16. For this reason, since the leaf spring 16 is pressed only to the axial center side, it is difficult to be twisted. In addition, a force is applied to the brake wheel 10 only in the radial direction.

In this embodiment, the cam member 15 is attached to the armature 7 to form an inclined cam surface. However, as shown in FIGS. 3 and 4, the inclined cam surface is formed by forming the armature 7. Can also be configured. FIG. 3 is a plan view showing another embodiment in which the inclined cam surface is integrally formed with the armature, and FIG. 4 is a sectional view taken along the line IV-IV in FIG. In these figures, the same or equivalent members as those described in FIG. 1 and FIG. 2 are denoted by the same reference numerals, and detailed description is omitted. In these figures, reference numeral 21 denotes an inclined cam surface, which is formed by cutting and raising a part of the outer peripheral portion of the armature 7 in a laterally V-shape. Reference numeral 22 denotes a cut and raised portion. Reference numeral 23 denotes a stopper for preventing the ball 13 from deviating from the inclined cam surface 21. The stopper 23 is formed by bending a part of the side plate 11 and projecting it to the armature 7 side. The ball 13 extends in the radial direction at positions on both sides in the circumferential direction of the side plate 11 from the ball 13. In this case, in addition to the effect obtained by applying only a radial component force to the leaf spring 16, the cam member shown in the above-described embodiment can be eliminated, and the manufacturing cost can be reduced. be able to.

In each of the above-described embodiments, the brake wheel 10 is used as an example of the brake member, and the inner tightening type electromagnetic brake in which the outer peripheral surface of the flange 10b is used as a friction surface is shown. Alternatively, the present invention can be applied to an externally tightened electromagnetic brake in which a bottomed cylindrical brake drum is provided and its inner peripheral surface is used as a friction surface, and the same effect is obtained. In this case, the inclined cam surface provided on the armature 7 is directed radially outward, and a ball is placed between the inclined cam surface and the brake shoe supporting leaf spring located on the inner peripheral side of the brake drum. To interpose. In addition,
The side plate, which receives the axial component force applied to the ball, is located within the inner periphery of the brake drum.

[0014]

As described above, in the electromagnetic brake according to the present invention, the inclined cam surface is formed on the armature, and the flat stopper surface extending in the radial direction is provided on the opposite side of the armature from the field core. The side plate formed on the armature side is fixed, and the rolling element is brought into contact with the stopper surface to be interposed between the inclined cam surface and the brake shoe supporting leaf spring. The axial component when pressed by the operation is received by the side plate, and only the radial component is applied to the brake shoe supporting leaf spring. For this reason, the plate spring for supporting the brake shoe is pressed only to the axial center side, so that it is difficult to be twisted, and a force is applied only to the brake member in the radial direction. Therefore, since no force is applied to the brake member in the axial direction, the durability of the device does not decrease even if the brake shoe supporting leaf spring is not formed with high rigidity. An electromagnetic brake is obtained.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a plan view showing another embodiment in which the inclined cam surface is integrally formed with the armature.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

[Explanation of symbols]

 2 Field core 7 Armature 8 Brake spring 10 Brake wheel 11 Side plate 13 Ball 14 Inclined groove 15 Cam member 16 Plate spring 18 Brake shoe 21 Inclined cam surface

Claims (1)

(57) [Scope of request for utility model registration] An armature movably supported in the axial direction by the field core and urged away from the field core by a braking spring, and elastically supported by the field core movably in the radial direction via a leaf spring. A brake shoe opposed to a peripheral surface of a brake member rotating with respect to a field core, and interposed between the armature and a brake shoe supporting leaf spring, and moved along an inclined cam surface to move in an axial direction of the armature. An electromagnetic brake having a rolling element for changing the operation to a radial operation and urging a brake shoe, wherein the inclined cam surface is formed in an armature, and the inclined cam surface extends in a radial direction from the armature to a side opposite to the field core. An existing flat stopper surface fixes the side plate formed on the armature side, and the rolling element is An electromagnetic brake, wherein said electromagnetic brake is abutted against said stopper surface and interposed between said inclined cam surface and said brake shoe supporting leaf spring.