JP2669748B2 - 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, and more particularly, to a bobbin on which an exciting winding is wound and a bobbin of the friction plate type electromagnetic brake having a friction plate driven in an axial direction by an electromagnetic force. The present invention relates to improvement of a mutual fixing structure with a brake core.

[0002]

2. Description of the Related Art A friction plate type electromagnetic brake is often used to hold a rotating body to which a static load is applied when stopped, such as an output shaft of an electric motor used for a gravity axis of a machine tool. This type of friction plate type electromagnetic brake has an excitation winding for generating an electromagnetic force that drives the friction plate, a brake core around which the excitation winding is made of a magnetic material, and a predetermined gap on the end surface of the brake core. And an end plate that is fixed in place, a friction plate and an armature for driving the friction plate that are movably inserted in the gap in the axial direction. The friction plate is connected to a rotating body such as an output shaft by an engaging structure such as gear teeth,
It can rotate together with the rotating body and can move in the axial direction.
It is arranged between the end plate and the armature. The armature is a plate member made of a magnetic material, and is arranged so as to face the brake core, and moves in the axial direction by an electromagnetic force to hold or release mutual contact between the friction plate and the end plate.

The excitation winding is installed directly in the winding installation recess of the brake core, or is wound around the bobbin and then housed in the recess together with the bobbin. When installing directly,
It is necessary to wind the exciting winding on an external winding frame in advance to form a winding bundle, and after removing this winding bundle from the winding frame, it is necessary to install the winding bundle in the concave portion of the brake core. Is simplified. The bobbin is generally made of plastic, and is fixed to the recess of the brake core by an adhesive after winding the exciting winding.

[0004]

When a bobbin is used to wind the excitation winding around the brake core, the magnetic attraction force exerted on the armature during excitation prevents the bobbin from falling out of the recess of the brake core. First, it is necessary to securely fix the bobbin to the recess. Therefore, as described above, generally, an adhesive is used to firmly fix the bobbin in the recess. On the other hand, the excitation winding wound around the bobbin is generally subjected to an impregnation step with an impregnating material in order to fill the gaps in the winding bundle to strengthen the holding and mutual fixing of the winding. Therefore, the above-described bobbin-type winding structure requires a step of impregnating the excitation winding and a step of bonding the bobbin, which increases man-hours and consumes a large amount of work time because a long time is required for curing. was there.

The present invention has been earnestly devised and improved to solve the above problems, and an object thereof is to reliably secure the bobbin to the brake core in an electromagnetic brake having a bobbin type winding structure. An object of the present invention is to provide an electromagnetic brake having a bobbin fixing structure that can be fixed and that can reduce a manufacturing process and a working time related to manufacturing.

[0006]

In order to achieve the above object, the present invention provides a bobbin having a winding portion around which an excitation winding is wound, and a brake core having a recess for accommodating the bobbin. An electromagnetic brake comprising: a friction plate driven by an electromagnetic force applied from an exciting winding; and a fixing means for fixing a bobbin in a housing recess of a brake core, wherein the bobbin is a cylinder forming the winding portion. -Shaped center wall and a pair of annular plate-shaped side walls, and when the brake core is housed in the housing recess, one of the side walls is arranged to face the bottom wall of the housing recess and the other is arranged close to the opening of the housing recess. In addition, the other side wall is provided with a notch capable of partially opening the opening of the housing recess, and the fixing means is formed in at least one of the bobbin and the housing recess of the brake core. After the bobbin is housed in the housing recess of the brake core and locked, the notch formed in the other side wall of the bobbin is inserted into the housing recess. An electromagnetic brake is provided which is characterized in that an impregnating material is injected thereinto to hold the excitation winding fixed and to reinforce the bobbin fixing.

[0007]

The notch formed in the side wall of the bobbin disposed in the vicinity of the opening of the recess of the brake core accommodates the bobbin in the recess, and then the impregnating material for fixing the winding into the winding bundle of the excitation winding. Allows you to inject. The impregnating material penetrates into the winding bundle, the gap between the exciting winding and the bobbin, and the gap between the bobbin and the recess for accommodating the brake core to fix them to each other. Further, a locking portion formed on at least one of the bobbin and the housing recess of the brake core mechanically locks and holds the both.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings. In addition, in each drawing, the same reference numeral is given to the same component. FIG.
Referring to FIG. 1, the electromagnetic brake according to the first embodiment of the present invention includes a brake core 16 having an annular bobbin 12 around which an excitation winding 10 is wound, and a recess 14 for accommodating the bobbin 12.
An end plate 18 fixed to the end surface 16a of the brake core 16 with a predetermined gap, a friction plate 20 movably inserted in the gap in the axial direction (vertical direction in the drawing), and a friction plate driving member. Armature 22 of. The bobbin 12 is made of a flexible plastic material, and the winding portion 12c of the excitation winding 10 is formed by the cylindrical wall portion 12a and the pair of side wall portions 12b and 12c. The brake core 16 is made of a magnetic material such as iron, and has an inner cylindrical portion 16b, an outer cylindrical portion 16c, and an end surface 1b.
The annular recess 1 is formed by the bottom wall 16d on the opposite side of 6a.
4 is formed. The outer diameter of the inner tubular portion 16b of the brake core 16 and the inner diameter of the tubular wall portion 12a of the bobbin 12, and the inner diameter of the outer tubular portion 16c of the brake core 16 and the side wall portion 12 of the bobbin 12.
The outer diameters of b and 12c are substantially equal to each other.

Brake core 16, end plate 18, friction plate 2
Each of the armature 22 and the armature 22 is an annular member, and the shaft 24 is inserted into each of the inner diameter portions. End plate 1
A plurality of (three in the example in the figure) spacers 26 are provided between the end surface 16a of the brake core 16 and a plurality of (similarly three) screws 28 penetrating the end plate 18 and the spacer 26.
Is fixed to the brake core 16 by being screwed into a screw hole 28a (FIG. 2) provided in the end face 16a. Friction plate 20
Is connected to the shaft 24 by a plurality of gear teeth (not shown), is slidable in the axial direction, and rotatable integrally with the shaft 24. The armature 22 is made of a magnetic material, has a plurality of holes 22a through which the spacers 26 are inserted, and is arranged to face the end surface 16a of the brake core 16, and is axially moved along the spacers 26 by the electromagnetic force generated by the exciting winding 10. Slide. A plurality of coil springs 30 are provided between the armature 22 and the end surface 16 a of the brake core 16.
Is installed. The coil spring 30 is accommodated in a compressed state in a slot 31 (FIG. 2) provided in the end surface 16a so as to constantly urge the armature 22 toward the end plate 18. Normally, the urging force causes the friction plate 20 to come into strong contact with the end plate 18, thereby holding the shaft 24 stationary. At this time, a minute gap S is formed between the armature 22 and the end surface 16a of the brake core 16. When a current flows through the excitation winding 10, the armature 22 is attracted to the end surface 16a of the brake core 16 by the electromagnetic attraction force against the bias of the coil spring 30, and the contact between the friction plate 20 and the end plate 18 is released. , Which causes the shaft 24 to rotate freely.

The electromagnetic brake of FIG. 1 has a brake core 16
The inner cylindrical portion 16b has a locking portion 32 protruding outward in the radial direction at the end on the end face 16a side (see FIG. 3). Locking part 3
The reference numeral 2 constitutes a fixing means for fixing the bobbin 12 in the recess 14 of the brake core 16, and the bobbin 12 can be formed continuously over the entire circumference of the tip of the inner cylindrical portion 16b. You may divide and form. The locking portion 32 is the brake core 1
6 has a tapered portion 32a on the side of the end surface 16a. In addition, the axial length of the inner wall portion of the inner tubular portion 16b excluding the locking portion 32 is substantially equal to the axial length of the outer wall portion of the tubular wall portion 12a of the bobbin 12. Therefore, when the bobbin 12 around which the exciting winding 10 is wound is inserted into the concave portion 14 of the brake core 16, the corner connecting the cylindrical wall portion 12 a of the bobbin 12 and one (the lower side in the drawing) side wall portion 12 b becomes The taper portion 32a of the locking portion 32 is pressed inward in the radial direction, and the cylindrical wall portion 12a slides on the locking portion 32 while the bobbin 12 is slightly deformed by the reaction force. In addition, bobbin 12
One side wall portion 12 b is the bottom wall portion 16 of the brake core 16.
a) to contact the bobbin 1 into the recess 14 of the brake core 16.
When 2 is completely accommodated, the corner portion connecting the cylindrical wall portion 12a of the bobbin 12 and the other side wall portion 12c (upper side in the figure) is locked by the locking portion 32, and the bobbin 12 in the recess 14 is locked.
Axial displacement is prevented.

Further, the electromagnetic brake of FIG.
The other side wall portion 12c is provided with a plurality of notches 34 penetrating it in the axial direction (see FIG. 2). Bobbin 1
The other side wall portion 12c of 2 substantially closes the opening of the recess 14 of the brake core 16 as shown in FIG. 2, but each notch 34 partially opens this opening. . Therefore, after the bobbin 12 in which the excitation winding 10 is wound is housed in the recess 14 of the brake core 16 and locked by the locking portion 32 as described above, the impregnating material 36 is inserted into the opening of the recess 14 as shown in FIG. Is injected, impregnating material 36
Passes through each of the notches 34, and in the winding bundle of the excitation winding 10,
It penetrates into the gap between the exciting winding 10 and the bobbin 12 and the gap between the bobbin 12 and the concave portion 14 of the brake core 16. After the impregnating material 36 is completely filled in the recess 14 as shown in FIG. 1 (b), it is heated and hardened in a furnace (not shown) to maintain the mutual fixation of the winding bundle, The bobbin 12 is fixed.

FIG. 4 shows an assembly of a brake core 16 and a bobbin 38 of an electromagnetic brake according to a second embodiment of the present invention. In this embodiment, the other side wall portion 38c of the bobbin 38 disposed on the end face 16a side of the brake core 16 has an outer diameter smaller than the inner diameter of the outer cylindrical portion 16c of the brake core 16, and the difference in diameter is caused by this difference in diameter. The other side wall portion 3 of the bobbin 38
An annular cutout 40 is formed surrounding 8c. The material and other structures are the same as those in the embodiment of FIG. 1, and the description thereof will be omitted. Therefore, after accommodating the bobbin 38 having the exciting winding wound in the recess 14 of the brake core 16,
When the impregnating material 36 is injected into the opening 4, the impregnating material 36 penetrates into the concave portion 14 through the annular cutout portion 40, and maintains the mutual fixing of the winding bundles by heat curing as in the embodiment of FIG. 1. At the same time, it assists in fixing the bobbin 12 in the recess 14.

FIG. 5 shows an assembly of a bobbin 42 and a brake core 44 of an electromagnetic brake according to a third embodiment of the present invention. In this embodiment, the other side wall portion 42c of the bobbin 42 disposed on the end face 44a side of the brake core 44 has a portion 42d having an outer diameter smaller than the inner diameter of the outer cylinder portion 44c of the brake core 44 and a circumferential direction 42d. A plurality of locking claws 46 are provided at predetermined intervals and project radially outward from the portion 42d. On the other hand, the outer cylinder portion 4 of the brake core 44
A plurality of locking claw portions 46 of the bobbin 42 are provided on the inner wall portion 4c.
Corresponding to the above, a plurality of locking groove portions 48 are engraved. Further, due to the above-mentioned difference in diameter between the portion 42d of the other side wall portion 42c of the bobbin 42 and the outer cylinder portion 44c of the brake core 44, a plurality of cutout portions 50 surrounding the other side wall portion 42c of the bobbin 42 are formed. To be done. Therefore, in this embodiment, the locking claw portion 46 and the locking groove portion 48 form a fixing means for fixing the bobbin 42 into the recess 52 of the brake core 44.

When the bobbin 42 around which the excitation winding 10 is wound is inserted into the recess 52 of the brake core 44, the plurality of claw portions 46 of the other side wall portion 42c of the bobbin 42 are inserted into the brake core 4.
4 is pressed inward in the radial direction by the inner wall portion of the outer cylindrical portion 44c of 4, and the bobbin 42 is accommodated in the recess 52 while slightly deforming. When one of the side wall portions 42b of the bobbin 42 comes into contact with the bottom wall portion 44d of the brake core 44, each locking claw portion 46 of the bobbin 42 fits into a corresponding locking groove portion 48, thereby the axial direction of the bobbin 42. Displacement is prevented. afterwards,
As shown in FIG. 5B, the recess 5 of the brake core 44 is
When the impregnating material 54 is injected into the openings 2, the impregnating material 54 penetrates into the recesses 52 through the plurality of notches 50, and maintains the mutual fixation of the winding bundle by heat curing as in the above-described embodiments. At the same time, it assists in fixing the bobbin 42 in the recess 52.

FIG. 6 shows an assembly of a bobbin 56 and a brake core 58 of an electromagnetic brake according to a fourth embodiment of the present invention. In this embodiment, the cylindrical wall portion 56a of the bobbin 56 and the inner cylindrical portion 58b of the brake core 58 have a substantially elliptical cross section that can abut each other. The bobbin 56 is inserted into the recess 60 of the brake core 58 in a state where the tubular wall portion 56a and the inner tubular portion 58b are aligned with each other, and then the bobbin 56 is removed while maintaining the contact between the tubular wall portion 56a and the inner tubular portion 58b. When the bobbin 56 is rotated as shown by the arrow in the drawing, the bobbin 56 is deformed by the substantially elliptical shape of the inner cylinder portion 58b, and is fixed in the recess 60 by its own elastic force. Therefore, in this embodiment, the locking portion 32 in the embodiment of FIG. 1 is omitted, but the other structure is the same as that of the second embodiment of FIG. 2, and by similarly injecting the impregnating material, the winding bundle is Are secured to each other and help secure the bobbin 56 in the recess 60.

[0016]

As is apparent from the above description, according to the present invention, a locking portion is formed on at least one of the bobbin of the electromagnetic brake and the recessed portion of the brake core, and the locking portion mechanically connects both. A notch is formed in the side wall of the bobbin arranged close to the opening of the accommodation recess of the brake core while retaining and holding, and after impregnating the bobbin in the accommodation recess, the impregnating material is injected into the accommodation recess from the notch. Since the structure that holds the excitation winding fixed and assists the fixing of the bobbin is secured, the bobbin can be securely fixed to the brake core to maintain the strength against mechanical vibration and shock. It is possible to reduce the number of manufacturing steps and the working time required for manufacturing by omitting the step of adhering the brake core to the brake core, and to manufacture a highly reliable electromagnetic brake with excellent productivity.

[Brief description of the drawings]

1A and 1B are diagrams of an electromagnetic brake according to a first embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a vertical sectional view taken along line I-I;
It is.

2 is a plan view of the bobbin / brake core assembly of the electromagnetic brake of FIG. 1, illustrating the impregnation step of the impregnating material.

3 is an exploded view of the bobbin / brake core assembly of the electromagnetic brake of FIG. 1, shown in a vertical cross-section along line III-III of FIG.

FIG. 4 is a plan view of a bobbin / brake core assembly of an electromagnetic brake according to a second embodiment of the present invention, which is a diagram illustrating an impregnating step of impregnating material.

FIG. 5 is a view of a bobbin / brake core assembly of an electromagnetic brake according to a third embodiment of the present invention, in which (a) is a plan view and (b) is a vertical cross-sectional view taken along line VV after impregnation material is injected. It is a figure which shows the state of.

FIG. 6 is a plan view of a bobbin / brake core assembly of an electromagnetic brake according to a fourth exemplary embodiment of the present invention.

[Explanation of symbols]

 10 ... Excitation winding 12, 38, 42, 56 ... Bobbin 14, 52, 60 ... Recessed portion 16, 44, 58 ... Brake core 18 ... End plate 20 ... Friction plate 22 ... Armature 24 ... Shaft 26 ... Spacer 28 ... Screw 30 ... Coil spring 32 ... Locking portions 34,40,50 ... Notch portions 36,54 ... Impregnated material 46 ... Locking claw portions 48 ... Locking groove portions

Claims (1)

(57) [Claims] 1. A bobbin having a winding portion around which an excitation winding is wound, a brake core having an accommodating recess for accommodating the bobbin, and a friction plate driven by an electromagnetic force exerted from the excitation winding. And an electromagnetic brake comprising a fixing means for fixing the bobbin in the housing recess of the brake core, wherein the bobbin includes a cylindrical center wall forming the winding portion and a pair of annular plate side walls, When the brake core is accommodated in the accommodating recess, one of the side walls is disposed to face the bottom wall of the accommodating recess and the other is disposed close to the opening of the accommodating recess, and the other side wall is accommodated in the accommodating recess. The fixing means includes a notch capable of partially opening the opening of the recess, and the fixing means includes a locking portion formed on at least one of the bobbin and the housing recess of the brake core to lock the two mutually. Equipped with the above After accommodating and locking the bin in the accommodation recess of the brake core, impregnating material is injected into the accommodation recess from the notch formed in the other side wall of the bobbin, and the exciting coil is An electromagnetic brake, characterized in that it holds the sticking and reinforces the fixing of the bobbin.