JP2019002517A - Electromagnetic brake - Google Patents

Abstract

To provide an electromagnetic brake which achieves downsizing while inhibiting deterioration of the strength.SOLUTION: An electromagnetic brake includes: a coil 4; a biasing part 6; a yoke 3; an armature 5 which is biased in a direction away from the yoke 3 by the biasing part 6 and is moved in a direction that comes close to the yoke 3 against biasing force by electromagnetic force of the coil 4; a brake part 7 which receives rotation of a braked rotary shaft to be rotatable and is inhibited from rotating by pressing force from the armature 5; and an outer shell part 2 which houses the brake part 7 and the armature 5. The outer shell part 2 includes: a peripheral wall part 21; a plate part 22 which receives the brake part 7 with the pressing force from the armature 5 to generate friction force between itself and the brake part 7; an opening 23 for inserting the brake part 7 and the armature 5; and a rotation prevention part which prevents rotation of the armature 5 around an axis.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic brake for applying braking to the rotation of a braked rotating shaft connected from the outside.

  Conventionally, as an electromagnetic brake used for industrial and medical robots, for example, an ultra-small brake having a diameter of less than 30 mm has been demanded. In such an ultra-small electromagnetic brake, since the plate portion and the yoke portion are very small parts, it is difficult to screw them together. Therefore, a configuration that does not perform screwing has been proposed.

  For example, there is one described in Patent Document 1. The electromagnetic brake includes an inner yoke portion provided with a coil, a cylindrical outer yoke portion covering the inner yoke portion, and a plate portion that is provided at an interval from the inner yoke portion and is integrally connected to the outer yoke portion. Are arranged on a reference axis, a braking part provided between the inner yoke part and the plate part so as to be rotatable around the reference axis of the yoke, an inner yoke part and a braking part, Between the armature disposed so as to be unrotatable around the reference axis and movable in the direction of the reference axis, and an urging portion for urging the armature against the braking portion. Two elongated holes into which the armature and the braking portion can be inserted are formed at predetermined intervals in the circumferential direction.

  In Patent Document 1, although the plate portion is integrally connected to the outer yoke portion, the connection by the screw becomes unnecessary and the size can be reduced. However, the two long holes for inserting the armature and the braking portion are disclosed. Must be formed in the circumferential direction of the outer yoke portion, leading to a decrease in strength of the outer yoke portion. In particular, in an ultra-compact electromagnetic brake, the thickness of the outer yoke portion is very thin. Therefore, in the configuration in which two long holes are formed in the outer yoke portion, there is a limit to downsizing, and early improvement is desired. .

JP 2011-149528 A

  Then, this invention makes it a subject to provide the electromagnetic brake which can implement | achieve size reduction, suppressing a strength fall.

  The electromagnetic brake according to the present invention includes a coil that generates an electromagnetic force when energized, an urging portion having an urging force, a magnetic body, a yoke around which the coil is wound, and moves away from the yoke by the urging force. An armature that is biased and moves in a direction approaching the yoke against the biasing force by the electromagnetic force, and a braked rotating shaft that is disposed on the opposite side of the armature from the yoke and connected from the outside. A braking portion that is rotatable in response to rotation and is prevented from rotating by receiving a pressing force from the armature that is moved and urged by the urging force; and an outer shell portion that accommodates at least the braking portion and the armature; The outer shell portion includes a peripheral wall portion positioned on the outer periphery of the brake portion and the armature, and both ends of the peripheral wall portion in the rotation axis direction of the brake portion. The brake is provided at least at one end, and the brake and the armature are arranged in the outer shell by an opening for inserting the brake and the armature, and the braking force by the pressing force from the armature. A plate portion for generating a frictional force with the braking portion by receiving the portion, an inner surface side of the peripheral wall portion, and the arranged armature, the armature being the braked rotating shaft And a rotation preventing portion for preventing rotation about the axis.

  According to the present invention, by inserting the braking portion and the armature into the outer shell portion through the opening provided at least at one end portion of both ends in the rotational axis direction of the braking portion of the peripheral wall portion in the outer shell portion, The braking part and the armature can be arranged inside the outer shell part. It is not necessary to form an opening like a conventional long hole in the peripheral wall portion. Therefore, the strength of the outer shell portion does not decrease. Further, the armature is prevented from rotating by the rotation preventing portion provided across the inner surface side of the peripheral wall portion and the armature only by arranging the armature inside the outer shell portion. And by providing a plate part in an outer shell part, it becomes unnecessary to integrate a peripheral wall part and a plate part with a screw, and it can attain downsizing correspondingly.

  In the electromagnetic brake of the present invention, the rotation preventing portion includes a locking portion provided in the armature, and a locked portion provided on an inner surface side of the peripheral wall portion locked to the locking portion. And the part to be locked may be a part of the unevenness formed over the inside and outside of the outer shell part.

  As described above, by making the locked portion of the peripheral wall portion constituting the rotation prevention portion a part of the unevenness formed over the inside and outside of the outer shell portion, for example, a small outer shell having a diameter of less than 30 mm It is possible to easily include the locked portion of the rotation preventing portion in the portion.

  The electromagnetic brake of the present invention may include a film-like insulating layer on at least a surface of the yoke that faces the armature.

  As described above, if the insulating layer is provided at least on the surface of the yoke facing the armature, the thickness of the insulating layer can provide a space between the surface of the yoke and the surface of the armature. It can be prevented from contacting directly. For this reason, there is a problem of noise caused by collision between the two when energized (at the time of adsorption) and a problem of performance degradation due to a time lag before they are separated due to residual magnetism when the electromagnetic force is eliminated. Can improve.

  The insulating layer is also provided on a surface where the coil wound around the yoke overlaps, and the insulating layer provided on a surface of the yoke facing the armature and a surface where the coil wound around the yoke overlaps. And the insulating layer provided in can constitute a series of layers.

  According to the said structure, compared with the structure by which the bobbin is arrange | positioned between a yoke and a coil or the space was ensured, the space between a yoke and a coil can be made to approach. If the yoke and the coil can be brought close to each other, the outer dimension of the outer shell can be reduced without reducing the number of turns of the coil. Therefore, the electromagnetic brake can be reduced in size. Further, by forming the two insulating layers as a series of layers, compared to the case where the insulating layers are separated, the labor of masking during the manufacturing is reduced, and the yoke having the insulating layer can be easily manufactured.

  According to the present invention, it is possible to provide an electromagnetic brake capable of realizing downsizing while suppressing a decrease in strength by disposing a braking portion and an armature inside an outer shell portion and providing a plate portion in the outer shell portion. it can.

The electromagnetic brake which concerns on one Embodiment of this invention is shown, (a) is a longitudinal cross-sectional view, (b) is a top view. It is a disassembled perspective view of the said electromagnetic brake. The armature which comprises the said electromagnetic brake is shown, (a) is a top view, (b) is a longitudinal cross-sectional view. The outer shell part which comprises the said electromagnetic brake is shown, (a) is a top view, (b) is the sectional view on the AA line in Fig.4 (a), (c) is the BB line in Fig.4 (a). It is sectional drawing. It is the longitudinal cross-sectional view which showed the part in which the insulating layer was formed in a). It is a longitudinal cross-sectional view which shows the part in which the insulating layer was formed in the electromagnetic brake.

  An embodiment of an electromagnetic brake according to the present invention will be described based on the drawings. Note that the description in the vertical direction below corresponds to the positional relationship shown in FIG.

  As shown in FIGS. 1A, 1B, and 2, the electromagnetic brake 1 includes an outer shell portion 2, a yoke 3, a coil 4, an armature 5, an urging portion 6, a braking portion 7, An input connection unit 8.

  The outer shell 2 is continuously formed on a cylindrical (or a rectangular tube) peripheral wall 21 that surrounds the outer periphery of a braked rotating shaft (not shown) connected from the outside, and an upper end of the peripheral wall 21. And a plate portion 22 that covers the outer diameter region of the upper end surface. The plate portion 22 receives the braking portion 7 with a pressing force from the armature 5. The lower end portion of the outer shell portion 2 is opened and serves as an opening portion 23 for inserting the braking portion 7 and the armature 5. A part of the outer shell 2 functions as an “outer yoke”, and the magnetic flux generated by the coil 4 passes therethrough. Therefore, the outer shell 2 is formed of a magnetic material.

  The yoke 3 is a portion around which the coil 4 is wound, and includes a disk-shaped base 31 that covers the opening 23 of the outer shell 2, and a shaft 32 that extends upward from the center of the base 31. The shaft portion 32 is hollow and open upward and downward, and the urging portion 6 is disposed above the inside of the shaft portion 32. A step portion 33 is formed inside the shaft portion 32, and the lower end of the urging portion 6 is fixedly supported by the step portion 33. Since the magnetic flux generated by the coil 4 passes through the yoke 3, the yoke 3 is made of a magnetic material. Further, the outer shell portion 2 and the yoke 3 are fixed by fitting. Specifically, the base 31 of the yoke 3 is pushed into (pressed into) the opening 23 of the outer shell 2 while applying pressure.

  The coil 4 is configured by winding an electric wire around a shaft portion 32 while being supported by a base portion 31 of the yoke 3 (the electric wire itself is not shown). For this reason, the coil 4 is wound around the central axis. The electric wire passes through the peripheral wall portion 21 of the outer shell portion 2 and is taken out as a cable C to the outside. Electric power is supplied to the electromagnetic brake 1 via the cable C, and an electromagnetic force is generated in the coil 4 by energizing the electric wire. This electromagnetic force reaches the armature 5 through a part of the outer shell 2 and the yoke 3. Specifically, during energization, a force that is attracted to the yoke 3 acts on the armature 5 against the urging force of the urging portion 6.

  As the electric wire constituting the coil 4, it is desirable to use, for example, a self-bonding electric wire, specifically, a hot-air bonding type self-bonding electric wire. By using the self-bonding electric wire, the electric wire can be hardened while being wound, so that the winding of the electric wire is not broken and the coil 4 having a well-formed shape can be obtained. This is advantageous when a thin electric wire is used in order to manufacture an ultra-small electromagnetic brake 1 having a diameter of less than 30 mm.

  As shown in FIGS. 3A and 3B, the armature 5 has a plate-like shape, and a through hole 52 for passing a braked rotating shaft is formed in the center, and the discs are opposed to each other in the radial direction. By chamfering, a substantially oval shape having opposing sides 51, 51 is obtained. As shown in FIGS. 4A to 4C, the inner surface shape of the outer shell portion 2 is the same shape that is slightly larger than the outer peripheral shape of the armature 5. Thereby, the opposing sides 51 and 51 which are the latching | locking parts of the armature 5 are formed in the inner surface of the outer shell part 2 (peripheral wall part 21), allowing the armature 5 to reciprocate to an axial direction (up-down direction). The armature 5 is prevented from rotating around the axis of the braked rotating shaft by being locked to the opposed surfaces 211 and 211 that are the locked portions. The opposing sides 51 and 51 of the armature 5 and the opposing surfaces 211 and 211 of the inner surface of the outer shell portion 2 constitute a rotation preventing portion X. The armature 5 is disposed opposite to the upper end surface of the yoke 3 and moves in a direction approaching the yoke 3 by electromagnetic force generated by the coil 4 when energized. The armature 5 moves away from the yoke 3 by the urging force of the urging portion 6 in a state where the electromagnetic force disappears when the current is not energized.

  Opposing surfaces 211 and 211 that are locked portions constituting the rotation preventing portion X are part of the unevenness formed over the inside and outside of the outer shell portion 2. The unevenness is formed by pressing (for example, drawing) the outer shell portion 2. Moreover, this unevenness | corrugation can be formed, for example so that it may have a plane in the inner surface of the outer shell part 2, and in that case, this plane turns into the opposing surfaces 211,211. Specifically, when the outer shell portion 2 is formed, by partially squeezing (drawing), the inner surfaces of the peripheral wall portion 21 are protruded radially inward to form the opposing surfaces 211 and 211. Further, the opposing surfaces 211 and 211 may be formed so as to protrude radially inward by caulking (also referred to as caulking) in which a part of the outer shell 2 is recessed after the outer shell 2 is formed. In this manner, the outer shell portion 2 is deformed to form the locked portions (here, facing surfaces 211 and 211) of the peripheral wall portion 21 constituting the rotation preventing portion X over the inside and outside of the outer shell portion 2. Can be a part of the unevenness. Therefore, for example, the small outer shell portion 2 having a diameter of less than 30 mm can be easily provided with the locked portions (here, the opposing surfaces 211 and 211) of the rotation preventing portion X.

  The urging unit 6 is a compression coil spring that expands and contracts in the axial direction (vertical direction in the present embodiment). The urging force of the urging unit 6 urges the armature 5 to move away from the yoke 3. The electromagnetic force acting on the armature 5 when energized is set to be larger than the urging force of the urging unit 6. For this reason, when energized, the electromagnetic force overcomes the urging force of the urging unit 6, and the armature 5 moves in a direction approaching the yoke 3.

  The braking portion 7 is disposed on the opposite side of the armature 5 from the yoke 3, and has a circular outer shape and a plate shape. A round step portion 24 that is slightly larger than the brake portion 7 is formed in the outer shell portion 2 (see FIGS. 1 and 4A to 4C). The braking unit 7 is rotatable around the braked rotating shaft while being accommodated in the stepped portion 24. When the outer shell portion 2 abuts against the lower surface 221 of the plate portion 22 and the upper surface of the armature 5, the rotation of the braking portion 7 is prevented by the frictional force with respect to each surface. In the through hole 71 (see FIG. 2) formed at the center of the braking portion 7, the input connecting portion 8 is fitted and fixed so as to rotate coaxially. Although not shown, the input connecting portion 8 is connected to the braked rotating shaft of the object to be braked.

  In the electromagnetic brake 1 of the present embodiment configured as described above, the armature 5 is pushed up by the urging force of the urging unit 6 when not energized, and the braking unit is interposed between the armature 5 and the plate unit 22 of the outer shell unit 2. The rotation of the input connecting portion 8 is stopped by sandwiching 7. On the other hand, when energized, the armature 5 moves downward by the electromagnetic force of the coil 4. Then, the braking portion 7 is separated from the plate portion 22 and the armature 5 of the outer shell portion 2 or is slidable. Thereby, the rotation of the input connecting portion 8 is allowed.

  When assembling the electromagnetic brake 1 of the present embodiment, the braking portion 7 and the armature 5 are connected to the outer shell portion 2 through an opening 23 provided at one end portion in the rotation axis direction of the braking portion 7 of the peripheral wall portion 21 of the outer shell portion 2. The brake part 7 and the armature 5 can be disposed inside the outer shell part 2 by being inserted into the outer shell part 2. At this time, the braking portion 7 is accommodated in the step portion 24 of the outer shell portion 2, and the armature 5 is removed so that the opposing sides 51, 51 of the armature 5 are engaged with the opposing surfaces 211, 211 of the inner surface of the outer shell portion 2. Housed in shell 2. In FIG. 2, the braking portion 7 and the armature 5 are inserted from the opening 23 at the lower end of the outer shell portion 2, but the outer shell portion 2 is turned upside down so that the opening 23 becomes the upper end. You may insert the braking part 7 and the armature 5 from the opening part 23 located in the upper end of the shell part 2. FIG. It is not necessary to form an opening like a conventional long hole in the peripheral wall portion 21 of the outer shell portion 2. Therefore, the strength of the outer shell portion 2 does not decrease. Further, the rotation of the armature 5 is prevented by the rotation prevention portion X provided across the inner surface side of the peripheral wall portion 21 and the armature 5 only by arranging the armature 5 inside the outer shell portion 2. And since the plate part 22 is provided in the rotation-axis direction other end part of the braking part 7 of the surrounding wall part 21, it becomes unnecessary to integrate the surrounding wall part 21 and the plate part 22 with a screw | thread, and it is small correspondingly. Can be achieved. After putting the brake part 7 and the armature 5 in the outer shell part 2, the assembly of the electromagnetic brake 1 is completed by pushing the yoke 3 including the coil 4 and the biasing part 6 while applying pressure to the outer shell part 2. To do.

  Further, in the present embodiment, as shown in FIG. 5, a film-like insulating layer 9 (upper insulating layer 9 a) is provided on the upper end surface that is at least the surface facing the armature 5 in the yoke 3. The insulating layer 9 is a layer containing a resin component, and is specifically a coating film by painting. That is, the insulating layer 9 is made of a nonmagnetic coating film. The thickness of the insulating layer 9 is 30 μm to 70 μm, preferably 40 μm to 60 μm.

  Thus, by providing the insulating layer 9 (upper insulating layer 9a) on the upper end surface of the yoke 3, the space between the upper end surface of the yoke 3 and the lower surface of the armature 5 can be provided by the thickness of the insulating layer. 3 and the armature 5 can be prevented from contacting directly. For this reason, there is a problem of noise caused by collision between the two when energized (at the time of adsorption) and a problem of performance degradation due to a time lag before they are separated due to residual magnetism when the electromagnetic force is eliminated. Can improve. In order to solve these problems, for example, it may be possible to dispose a sheet made of a non-magnetic material such as a resin sheet or a cork sheet between the yoke 3 and the armature 5. There is an inconvenience that parts increase.

  Further, as shown in FIG. 5, an insulating layer 9 (lower insulating layer 9 b) is also provided on the surface where the coil 4 wound around the yoke 3 overlaps, and the insulating layer provided on the surface of the yoke 3 facing the armature 5. 9 (upper insulating layer 9a) and the insulating layer 9 (lower insulating layer 9b) provided on the surface where the coil 4 wound around the yoke 3 overlaps constitute a series of layers. The lower insulating layer 9b insulates the yoke 3 from the coil 4.

  By using the insulating layer 9 as a coating film, a thin film can be realized. Compared with a configuration in which a bobbin is disposed between the yoke 3 and the coil 4 or a space is ensured, the yoke 3 and the coil 4 are disposed. Can be approached. If the yoke 3 and the coil 4 can be brought close to each other, the outer dimension of the outer shell portion 2 can be reduced without reducing the number of turns of the coil 4. Therefore, the electromagnetic brake 1 can be reduced in size. In addition, since the two insulating layers 9 (upper insulating layer 9a) and 9 (lower insulating layer 9b) are composed of a series of layers, it is more troublesome to mask during the manufacturing process than to separate the insulating layers. It is easy to manufacture a yoke having an insulating layer.

  The coating film that is the insulating layer 9 can be formed by various coating methods, but is preferably by electrodeposition coating. This is because the film formed by electrodeposition coating can make the film thickness uniform, so that when winding the coil 4, the winding of the electric wire is hardly disturbed, and the electromagnetic force generated by the coil 4 can be made uniform. In addition, since the winding of the electric wire is not easily disturbed, the unevenness generated on the outer periphery of the coil 4 can be reduced. Therefore, even when it is necessary to wind the insulating tape covering the outer periphery of the coil 4, the insulating tape can be easily and beautifully Can be rolled up. Furthermore, since the coil 4 does not come into contact with the inner peripheral surface of the peripheral wall portion 21 at the time of assembly, the insulating tape is not broken and the electric wire of the coil 4 is not damaged, so that the assembly operation can be facilitated.

  Electrodeposition coating can be performed by a known method. Briefly, a yoke 3 is formed in an electrolytic solution containing resin, and a coating film is formed on the surface of the yoke 3 by energizing the electrolytic solution. Masking treatment is performed in advance on the portion where the coating film is not formed. In addition, when the surface of the yoke 3 is plated in advance, the plating is peeled off by pickling or the like at the portion where the insulating layer 9 is to be formed. In the present embodiment, a coating film is partially formed on the surface of the yoke 3, but it is also possible to form a coating film on the entire surface.

  The electromagnetic brake according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  In the above embodiment, the outer shell 2 and the yoke 3 are fixed by press-fitting the base 31 of the yoke 3 into the opening 23 of the outer shell 2. The size relationship between the opening portion 23 of the outer shell portion 2 and the base portion 31 of the yoke 3 is set so that the base portion 31 of the yoke 3 can be easily inserted, and the opening surface of the opening portion 23 of the outer shell portion 2 or Alternatively, the adhesive may be applied to the outer peripheral surface of the base 31 of the yoke 3, and then the base 31 of the yoke 3 may be inserted into the opening 23 of the outer shell 2 to fix them together with the adhesive.

  In the above embodiment, the outer shell 2 accommodates the yoke 3 having the braking portion 7, the armature 5, the coil 4 and the biasing portion 6. However, the outer shell 2 has the braking portion 7 and the armature 5. The yoke 3 including the coil 4 and the biasing portion 6 is housed in an outer case different from the outer shell portion 2, and the yoke 3 is placed outside the outer shell portion 2 by fitting the outer shell portion 2 and the outer case together. You may fix indirectly through a case. The fitting in this case includes fixing by press-fitting and fixing by an adhesive.

  Moreover, in the said embodiment, although one armature 5 which comprises the rotation prevention part X was comprised in oval shape, what kind of shapes, such as a rectangular shape, an ellipse shape, a triangular shape, a polygonal shape, may be sufficient. In short, the shape of the outer shape of the armature 5 and the shape of the inner surface of the peripheral wall portion 21 may be considered so that the rotation of the armature 5 can be prevented.

  In the embodiment, the outer shell 2 is configured by integrally forming the plate portion 22 at one end portion in the rotation axis direction of the braking portion 7 of the peripheral wall portion 21. The brake part 7 and the armature 5 are inserted into the inside of the peripheral wall part 21 through one of the openings at both ends of the cylindrical peripheral wall part 21 after the insertion. In this case, the outer shell portion 2 may be configured by bonding and fixing the plate portion 22 to either one end portion of both ends of the braking portion 7 of the peripheral wall portion 21 in the rotation axis direction using an adhesive.

  Moreover, in the said embodiment, although the coating film which is the insulating layer 9 was formed by electrodeposition coating, it can form by electrostatic coating, a radiant process (trademark), and thermal spraying, for example.

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic brake, 2 ... Outer shell part, 3 ... Yoke, 4 ... Coil, 5 ... Armature, 6 ... Energizing part, 7 ... Braking part, 8 ... Input connection part, 9 ... Insulating layer, 9a ... Upper insulating layer , 9b ... Lower insulating layer, 21 ... Peripheral wall part, 22 ... Plate part, 23 ... Opening part, 31 ... Base part, 32 ... Shaft part, 33 ... Step part, 51 ... Opposite side, 52 ... Through hole, 71 ... Through hole , 211 ... opposing surface, 221 ... lower surface, C ... cable, X ... rotation prevention part

Claims (4)

A coil that generates an electromagnetic force by energization, an urging portion having an urging force, and a yoke around which the coil is wound, and is moved and urged in a direction away from the yoke by the urging force, and the electromagnetic force The armature that moves in the direction of approaching the yoke against the biasing force and the armature disposed on the opposite side of the yoke, and is rotatable by receiving the rotation of the braked rotating shaft connected from the outside. A braking portion that is prevented from rotating by receiving a pressing force from the armature that is moved and urged by the urging force, and an outer shell portion that accommodates at least the braking portion and the armature,
The outer shell portion is provided at at least one end portion of a peripheral wall portion positioned on the outer periphery of the brake portion and the armature and both ends of the brake portion in the rotation axis direction of the brake portion, and the brake portion and the armature Between the opening for inserting the braking portion and the armature and the braking portion by receiving the braking portion with a pressing force from the armature. Rotation prevention that is provided across the plate portion for generating the vibration, the inner surface side of the peripheral wall portion, and the arranged armature, and prevents the armature from rotating about the axis of the braked rotating shaft. And an electromagnetic brake.   The rotation preventing portion includes a locking portion provided in the armature and a locked portion provided on an inner surface side of the peripheral wall portion locked to the locking portion, and the locked portion is The electromagnetic brake according to claim 1, wherein the electromagnetic brake is a part of irregularities formed over the inside and outside of the outer shell portion.   The electromagnetic brake according to claim 1, wherein a film-like insulating layer is provided on at least a surface of the yoke that faces the armature. The insulating layer is also provided on a surface where the coil wound around the yoke overlaps,
The insulating layer provided on a surface of the yoke facing the armature and the insulating layer provided on a surface of the yoke where the wound coil overlaps constitute a series of layers. Item 4. The electromagnetic brake according to item 3.

Images