JP5046851B2 - Non-excitation electromagnetic brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low cost, light weight, compact non-excitation operation type electromagnetic brake enabling reduction of the number of components, working man-hours, assembling man-hours and the like. <P>SOLUTION: A field core 5 is fixed on a housing 3 of a motor 2 having an excitation coil 3 built therein. A hub 9 is fixed on a rotary shaft 7, and an armature 10 is provided movably in an axial direction between the hub 9 and the field core 5. A permanent magnet 11 for braking magnetically attracting the armature 10 is fixed the hub 9. A buffer plate 28 is provided on the permanent magnet 28. Rotation of the armature 10 is prevented by engagement of engagement parts 20, 31b provided on the field core 5 and the armature 10. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention is used as a braking device for a braked member such as a rotating shaft of a braked device or a rotating member driven by a driving device, and holds the braked member in a stationary state when the excitation coil is not excited. The present invention relates to an excitation actuated electromagnetic brake.

  As conventional non-excitation operation type electromagnetic brakes, for example, electromagnetic brakes disclosed in Patent Documents 1 and 2 are known.

  In the non-excitation operation type electromagnetic brake disclosed in Patent Document 1, the permanent magnets are opposed to each other on the mutually opposing surfaces of the field core and the armature, and the polarities of the magnetic poles on the opposing surfaces are the same. It is arranged. In the electromagnetic brake, the armature is pressed against the brake disk by the magnetic repulsive force of the pair of permanent magnets in a non-excited state in which the energization to the exciting coil is cut off. Accordingly, when the exciting coil is energized and energized, the armature moves against the magnetic repulsive force of the permanent magnet by the magnetic attraction force of the magnetic flux, and is magnetically attracted to the magnetic pole surface of the field core. The brake is released.

  The non-excitation actuating electromagnetic brake disclosed in Patent Document 2 applies a required braking force by pressing the armature to the hub through a friction plate made of silicon rubber or the like by a braking spring when the excitation coil is not excited. Thus, the hub is released by attracting the armature against the spring and attracting it to the field core by energization excitation of the exciting coil.

Japanese Utility Model Publication No. 7-41081 Japanese Utility Model Publication No. 57-122836

  However, the above-described non-excitation operation type electromagnetic brake described in Patent Document 1 requires at least two permanent magnets facing each other, and has a recess for fitting the permanent magnets on the opposing surfaces of the field core and the armature. Since it is necessary to perform additional processing for each, there is a problem that the manufacturing cost of the entire apparatus increases, which is a major obstacle to cost reduction. In addition, if the concave portion for fitting the permanent magnet is formed in the magnetic circuit of the exciting coil, the magnetic resistance in the circuit increases, and the magnetism for moving the armature to the field core side against the magnetic repulsive force of the permanent magnet. There was also a problem that the suction force was reduced. For this reason, it is conceivable to increase the current value of the exciting coil and increase the magnetic attractive force. However, in this case, there arises a new problem that the heat generation amount and the power consumption amount increase.

The non-excitation actuated electromagnetic brake described in Patent Document 2 described above cannot be reduced in size compared to the case where a permanent magnet is used because the braking spring itself increases in size when attempting to obtain a large braking force. There was a problem. Therefore, it is conceivable to use a pair of permanent magnets as in the electromagnetic brake described in Patent Document 1 in place of the braking spring in order to enable downsizing. Arises as a new problem.
Further, since the rotation of the armature is prevented by the rotation prevention pin protruding from the core and the insertion hole formed in the armature through which the pin is inserted, the number of parts is increased because the pin is required, and the pin Requires drilling and driving.

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to reduce the number of parts, processing man-hours, assembly man-hours, etc. It is to provide.

In order to achieve the above object, the present invention provides a field core fixed to a fixed portion of a braked device, a hub fixed to a rotating shaft of the braked device, and an axially movable movement on the rotating shaft. An armature located between the field core and the hub, an excitation coil incorporated in the field core and magnetically attracting the armature during energization excitation and attracting it to the magnetic pole surface of the field core, and fixed to the hub A permanent magnet that couples the hub and the armature with a magnetic attraction force when the exciting coil is not energized to brake the rotating shaft, and the outer pole member constituting the field core is opposite to the braked device. A plurality of engaging portions are formed at the opening edge, and the outer peripheral edge of the armature protrudes toward the braked device side so as to be always in contact with the engaging portion of the field core. Combined, and forming a plurality of engaging portions for preventing rotation allows only axial movement of the armature by engaging.

  Moreover, this invention provides the buffer plate in the surface facing the said armature of the said permanent magnet in the said invention.

  Furthermore, the present invention is the above invention, wherein the permanent magnet is formed in an annular shape, and an annular step portion into which the permanent magnet is fitted is formed on a magnet mounting surface of a hub to which the permanent magnet is mounted. .

In the present invention, a predetermined braking force is obtained by coupling the hub and the armature by the magnetic attraction force of the permanent magnets. Therefore, it is only necessary to provide the permanent magnets only on the hub. It is possible to reduce the man-hours and assembly man-hours required for the armature and the armature. Further, it is not necessary to cancel the magnetic flux of the permanent magnet with the magnetic flux of the exciting coil. In addition, since the engaging portion that engages the field core and the armature is provided, thereby allowing only the movement of the armature in the axial direction and preventing the rotation, there is no need to provide another member for preventing rotation, The number of parts can be reduced.

  Further, in the present invention, since the buffer plate is provided, the impact and magnetic adsorption sound when the armature hits the permanent magnet are absorbed by the magnetic attractive force of the permanent magnet, and the permanent magnet is prevented from being damaged by the impact. Can do.

  Furthermore, in the present invention, the permanent magnet is formed in an annular shape, and the annular step portion into which the magnet is fitted is formed on the magnet mounting surface of the hub, so that the number of parts of the magnet is small, and the formation of the magnet mounting surface is performed. And magnet positioning is easy.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
1 is a sectional view in a non-excited state showing an embodiment of a non-excited operation type electromagnetic brake according to the present invention, FIG. 2 is a sectional view in an excited state, and FIG. 3 (a) is a front view of an inner pole member of a field core. FIG. 4B is a sectional view taken along line III-III, FIG. 4 is a perspective view of an outer pole member of the field core, FIG. 5A is a front view of the armature, and FIG. 5B is a sectional view taken along line VV. In these drawings, a non-excitation actuating electromagnetic brake generally indicated by reference numeral 1 includes a field core 5 fixed to one side surface of a housing 3 of a small motor 2 as a braked device by a plurality of bolts 4, An excitation coil 6 incorporated in the field core 5, a hub 9 fixed by a set screw 8 to a protruding end 7 a protruding from the housing 3 of the rotating shaft 7 of the motor 2, and a protruding end of the rotating shaft 7 7a is movably fitted in the axial direction and is positioned between the field core 5 and the hub 9, and the armature 10 is magnetically attracted to mechanically couple the hub 9 and the armature 10 together. Permanent magnet 11 or the like.

  The field core 5 is formed in a cylindrical shape by two members of an inner pole member 12 and an outer pole member 13, and supports the armature 10 so as to be movable in the axial direction while preventing rotation.

  In FIG. 3, the inner pole member 12 is formed in a cylindrical body with a flange by a magnetic material such as a low carbon steel material for machine structure, whereby a through hole 14 through which the projecting end portion 7a of the rotating shaft 7 passes. 12A, and a flange 12B integrally projecting from one end of the cylindrical portion 12A. Between the outer peripheral surface of the cylindrical portion 12A and the outer pole member 13, an annular recess 15 for accommodating the exciting coil 6 is formed as shown in FIG. The flange 12B is formed with three bolt mounting holes 16 through which the bolts 4 are inserted, and three stepped holes 17 for caulking and fixing the outer pole member 13. The bolt mounting holes 16 are formed at equal intervals in the circumferential direction near the outer periphery of the flange 12B. The stepped holes 17 are located on the inner side of the bolt mounting holes 16 and are formed at equal intervals in the circumferential direction and between adjacent bolt mounting holes 16. Further, the stepped hole 17 includes a circular arc-shaped concave portion 17a formed on the surface facing the motor 2 and a rectangular through hole 17b formed in the center of the bottom surface of the concave portion 17a and opened on the back surface of the flange 12B. It consists of and.

  In FIG. 4, the outer electrode member 13 is formed in a cylindrical shape whose both ends are opened by a carbon steel pipe for machine structure like the inner electrode member 12, and is used for three caulking at the opening edge on the motor 2 side. A protrusion 18 and a lead wire drawing groove 19 are formed. The caulking projections 18 are tongue pieces that are large enough to pass through the through holes 17b of the flange 12B, and are projected at equal intervals in the circumferential direction. The lead wire lead-out groove 19 is formed so as to be positioned between two adjacent projecting portions 18 and 18. On the other hand, three engaging portions 20 are formed on the opening edge of the outer pole member 13 opposite to the motor 2 side. The engaging portions 20 are formed of rectangular grooves that are long in the axial direction of the outer electrode member 13, and are formed at equal intervals in the circumferential direction of the outer electrode member 13. Such an outer pole member 13 is fitted into the cylindrical portion 12A of the inner pole member 12, the caulking projection 18 is inserted into the stepped hole 17, and the tip end thereof is caulked in the recess 17b, whereby the inner pole It is integrally coupled with the member 12 and covers the exciting coil 6.

  The exciting coil 6 is wound around a coil bobbin 21. The coil bobbin 21 includes a cylindrical portion 21a around which the exciting coil 6 is wound, and a pair of flange portions 21b and 21b integrally provided at both end openings of the cylindrical portion 21a. It is fitted to 12A and fixed with an adhesive or the like. An annular groove 23 for receiving the lead wire 22 of the exciting coil 6 is formed on the outer peripheral surface of the flange 21b on the motor 2 side of the two flanges 21b. The lead wire 22 is drawn out of the field core 5 through the lead wire lead-out recess 19 of the outer electrode member 13 and connected to a power source.

  The hub 9 is formed of a magnetic material such as a low carbon steel material for mechanical structure, like the inner pole member 12 and the outer pole member 13, and is a cylindrical boss portion that fits into the protruding end portion 7a of the rotary shaft 7. 9A and a flange 9B integrally projecting from one end of the boss portion 9A. The protruding end 7a of the rotating shaft 7 is formed in a D-shaped cross section. The boss 9A of the hub 9 has a D-shaped hole 25 that can be fitted into the protruding end 7a, thereby preventing the hub 9 from rotating relative to the rotating shaft 7. The rotation prevention structure of the hub 9 is not limited to this, and a key or the like may be used. The outermost peripheral portion of the surface 26 facing the armature 10 of the flange 9B forms a mounting surface of the permanent magnet 11, and is formed of an annular recess having an appropriate depth to form a step portion 27 into which the permanent magnet 11 is fitted. Have.

  The permanent magnet 11 is composed of an annular (disc-shaped) neodymium sintered magnet or the like magnetized in the plate thickness direction, and is fitted into the stepped portion 27 and fixed by an adhesive. A buffer plate 28 is fixed to the surface of the permanent magnet 11 facing the armature 10. The buffer plate 28 is formed in an annular shape having substantially the same size as the permanent magnet 11 by a polyurethane sheet or the like. The buffer plate 28 absorbs the impact and magnetic adsorption sound when the armature 10 is hit by the magnetic attractive force of the permanent magnet 11 when the excitation coil 6 is turned off, and prevents the permanent magnet 11 from being damaged by the impact. And has a function as a friction plate for the armature 10.

  In FIG. 5, the armature 10 is formed by punching a magnetic material such as a cold rolled steel plate into a disk shape by pressing, and a center hole 30 through which the outer end portion of the rotating shaft 7 is inserted; It has three engagement pieces 31 formed on the outer peripheral edge at equal intervals in the circumferential direction. The engaging piece 31 is formed in a tongue-like shape having a width that can engage with the engaging portion 20 of the outer pole member 13. The notch grooves 32 on both sides of the engagement piece 31 are for forming the engagement piece 31. The base 31a of the engagement piece 31 is bent obliquely to the field core 5 side, the distal end is parallel to the armature 10 and protrudes from the armature 10 to the motor 2 side to form the engagement portion 31b with the outer pole member 13. And it is slidably inserted into the engaging portion 20. The engaging portion 20 and the engaging piece 31 are always engaged, and the armature 10 is prevented from freely rotating. The outer diameter of the armature 10 is about 30 mm, and the axial dimension of the brake 1 is about 30 mm.

  In the non-excitation operation type electromagnetic brake 1 having such a structure, the armature 10 is magnetically attracted to the permanent magnet 11 by the magnetic flux 35 of the permanent magnet 11 as shown in FIG. It is separated from the magnetic pole surface 36 of the field core 5. However, since the engaging portion 20 of the field core 5 and the engaging portion 31b of the armature 10 are engaged, the rotating shaft 7 is braked.

  When the exciting coil 6 is energized to be excited, a magnetic flux 37 is generated, and the field core 5 and the armature 10 form a magnetic circuit of the magnetic flux 37 (see FIG. 2). For this reason, the armature 10 is attracted by the magnetic attraction force of the magnetic flux 37 against the magnetic attraction force of the permanent magnet 11 and is magnetically attracted to the magnetic pole surface 36 of the field core 5. Therefore, braking of the rotating shaft 7 by the non-excitation operation type electromagnetic brake 1 is released, and the motor 2 is driven.

  On the other hand, when the drive of the motor 2 is stopped and the energization of the exciting coil 6 is turned off to bring it into a non-excited state, the magnetic flux 37 disappears. When the magnetic flux 37 disappears, the armature 10 is attracted by the magnetic attractive force generated by the magnetic flux 35 of the permanent magnet 11 to be separated from the field core 5 and magnetically attracted to the permanent magnet 11 via the buffer plate 28 (FIG. 1). . Therefore, the rotating shaft 7 of the motor 2 can be held stationary.

  In addition, when the armature 10 is magnetically attracted to the hub 9 side at the start of braking by the non-excitation operation type electromagnetic brake 1, the shock acting on the permanent magnet 11 is absorbed by the buffer plate 28. Sound and damage to the permanent magnet 11 can be prevented. Furthermore, during braking, the buffer plate 28 is sandwiched and pressed by the armature 10 and the permanent magnet 11 by the magnetic attraction force of the permanent magnet 11, so that the stationary holding force of the rotating shaft 7 can be set large.

  As described above, the non-excitation actuating electromagnetic brake 1 according to the present invention has fewer parts, processing man-hours, and assembly man-hours than the electromagnetic brakes described in Patent Documents 1 and 2, and the excitation coil 6 is in an unexcited state. Thus, a small and inexpensive electromagnetic brake for holding the rotary shaft 7 of the small motor 2 in a stationary state can be provided.

  In the non-excitation operation type electromagnetic brake 1 shown in the present embodiment, the annular permanent magnet 11 is fixed to the flange 9B of the hub 9, but a plurality of permanent magnet pieces are divided in the circumferential direction on the flange 9B. It may be fixed.

It is sectional drawing in the non-excitation state which shows one Embodiment of the non-excitation actuating type electromagnetic brake which concerns on this invention. It is sectional drawing in an excitation state. (A) is a front view of the inner pole member of a field core, (b) is a III-III sectional view taken on the line. It is a perspective view of the outer pole member of a field core. (A) is a front view of an armature, (b) is a VV sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Non-excitation actuated electromagnetic brake, 3 ... Housing, 5 ... Field core, 6 ... Excitation coil, 7 ... Rotary shaft, 9 ... Hub, 10 ... Armature, 11 ... Permanent magnet, 20 ... Engagement part, 27 ... Step Part, 28 ... buffer plate, 31b ... engaging part, 36 ... magnetic pole surface.

Claims (3)

A field core fixed to a fixed portion of the braked device, a hub fixed to the rotation shaft of the braked device, and an axially movable movement between the field core and the hub. An armature positioned in the field core, an excitation coil that is magnetically attracted to the armature during energization excitation and is attracted to the magnetic pole surface of the field core, and a magnetic attraction force that is fixed to the hub and is not energized A permanent magnet for coupling the hub and the armature to brake the rotating shaft;
A plurality of engaging portions are formed on the opening edge of the outer pole member constituting the field core on the side opposite to the braked device,
A plurality of protrusions projecting toward the braked device at the outer peripheral edge of the armature so as to be always engaged with the engaging portion of the field core, thereby allowing only movement of the armature in the axial direction and preventing rotation. A non-excitation actuating electromagnetic brake characterized in that an engaging portion is formed . In the non-excitation operation type electromagnetic brake according to claim 1 ,
A non-excitation actuated electromagnetic brake characterized in that a buffer plate is provided on a surface of the permanent magnet facing the armature. In the non-excitation operation type electromagnetic brake according to claim 1 or 2 ,
The permanent magnet is formed in an annular shape, and an annular stepped portion into which the permanent magnet is fitted is formed on a magnet mounting surface of a hub to which the permanent magnet is mounted.

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