JP2017046542A - Commutator, motor with speed reducer and manufacturing method for commutator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a commutator and a manufacturing method for a commutator, which can reduce manufacturing time and simplify operation of a winding machine by eliminating work for winding a pressure-equalizing wire, and suppress manufacturing costs by simplifying a management process.SOLUTION: A commutator 14 comprises: a plurality of conductive segments 17 arranged in a tubular shape at intervals mutually in a circumference direction; a commutator main body 19 molded inside the plurality of segments 17 with an insulating member and externally fixed to a rotating shaft; and a pressure-equalizing plate unit, buried in the commutator main body 19, which connects the segments 17 which become the same potential of the plurality of segments 17 to each other. The pressure-equalizing plate unit comprises: a plurality of pressure-equalizing plates which connect the segments which become the same potential of the plurality of segments 17 to each other; and a unit main body, molded of an insulating member, which integrates the plurality of pressure-equalizing plates.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a commutator, a motor with a reduction gear, and a method of manufacturing a commutator.

  In general, a motor with a speed reducer decelerates rotational power generated by rotation of a stator having permanent magnets arranged at regular intervals on an inner peripheral surface of a cylindrical yoke, an armature rotatably provided inside the stator, and the rotation of the armature. And a speed reduction mechanism that mainly performs the operation. The armature includes an armature core that is externally fitted and fixed to the rotary shaft, and a commutator that is externally fitted and fixed to the rotary shaft so as to be adjacent to the armature core. The armature core includes a plurality of teeth extending along the radial direction, and windings are wound around these teeth.

  The commutator is mainly composed of a commutator main body made of resin and externally fixed to the rotary shaft, and a plurality of conductive segments arranged at intervals on the sliding surface of the commutator main body. A riser is formed at one end of the segment, and a winding wound around the teeth is locked to the riser. Thereby, the winding and the segment are conducted.

  Further, a plurality of brushes for supplying current are slidably contacted with the segments, and the windings are energized through these brushes, segments, and risers. Then, a magnetic field is generated in each tooth. The rotating shaft is rotated by a magnetic attractive force / repulsive force generated between the magnetic force of the magnetic field and the permanent magnet. Here, it is necessary to supply currents having a plurality of different phases to the windings wound around the teeth in order to continuously rotate the rotating shaft. For this reason, the segments are spaced apart from each other.

  By the way, there is a case where a pressure equalizing line for short-circuiting segments having the same potential among the segments arranged in the commutator is wound around the commutator. By comprising in this way, an electric current can be supplied also to the segment which the brush is not slidably contacting, and it becomes possible to reduce the installation number of a brush.

JP 2012-223048 A

However, in the above-described prior art, since the pressure equalizing wire is formed by windings, there is a problem that it takes time for the winding work process and manufacturing time increases.
In addition, in order to ensure the electrical connection between the voltage equalizing line and the segment having the same potential, on the other hand, in order to ensure the insulation from the voltage equalizing line connected to the segment having a different potential, the winding machine is provided near the riser. The operation becomes complicated. Therefore, there is a problem that the management process becomes complicated. Furthermore, there has been a problem that the manufacturing cost increases due to an increase in the amount of copper which is a raw material of the pressure equalizing wire.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a commutator, a motor with a reduction gear, and a method of manufacturing a commutator that can simplify the manufacturing process and the management process and reduce the manufacturing cost. To do.

  In order to solve the above-described problems, a commutator according to the present invention is formed by a plurality of conductive segments arranged in a cylindrical shape at intervals in the circumferential direction, and an insulating member formed inside the plurality of segments. A commutator body that is externally fitted and fixed to the rotating shaft, and a pressure equalizing plate unit that is embedded in the commutator body and connects segments of the same potential among the plurality of segments, the pressure equalizing plate unit, A plurality of pressure equalizing plates that connect segments having the same potential among the plurality of segments, and a unit main body that is formed of an insulating member and integrates the plurality of pressure equalizing plates. .

  With this configuration, it is possible to eliminate the work of winding the equalizing wire, shortening the manufacturing time, simplifying the operation of the winding machine, and simplifying the management process, thereby reducing the manufacturing cost of the commutator. Can be suppressed. Further, the pressure equalizing plate unit is not arranged on the outer side in the axial direction than the commutator body, and the axial length of the commutator can be suppressed.

  In the commutator according to the present invention, the pressure equalizing plate includes an annular part having a direction along the rotation axis as a central axis, an intermediate part extending from the annular part so as to follow the axial direction of the rotation axis, and the intermediate The unit main body may be formed so as to cover the annular part and the intermediate part.

  By comprising in this way, since between the pressure equalizing plates which a bubble tends to generate | occur | produce in the molding process of a commutator main body is previously covered with a unit main body, the filling failure of the resin in the molding process of a commutator main body can be suppressed.

    The commutator which concerns on this invention WHEREIN: You may arrange | position the said unit main body to the axial direction one end side of the said rotating shaft of the said segment.

  With this configuration, the pressure equalizing plate unit can be easily assembled to the commutator.

  The commutator which concerns on this invention WHEREIN: You may form the recessed part which can be fitted with the said electrical-connection part in the said axial direction end of the said segment.

  By configuring in this way, the electrical connection part and the recess fit together at one end in the axial direction, so that laser welding can be performed on all joints from one direction during laser welding, simplifying the welding operation. can do.

  In the commutator according to the present invention, the commutator body is formed by filling resin inside the plurality of segments, and the commutator body covers the unit body and a part of the electrical connection portion from the outside in the axial direction. It may be formed as follows.

  By comprising in this way, resin goes around to the axial direction outer side, and an electrical connection part is pressed by a segment via a unit main body by resin pressure. Further, the electrical connection portion is pressed against the segment by combining the upper mold and the lower mold of the mold. Therefore, the segment and the pressure equalizing plate can be reliably brought into contact with each other.

  In the commutator according to the present invention, the commutator main body is formed by filling resin inside the plurality of segments, and the plurality of pressure equalizing plates each have the annular portion spaced apart in the axial direction of the rotation shaft. In addition, the electrical connection portions may be formed on the same plane.

  By comprising in this way, since a pressure equalizing line is arrange | positioned at intervals, a short circuit can be prevented.

  In the commutator according to the present invention, the commutator body is formed by filling a resin inside the plurality of segments, and the resin inlet is set on one end side in the axial direction of the rotation shaft in the plurality of segments. In addition, the pressure equalizing plate unit may be disposed on the other axial end side of the rotating shaft.

  With this configuration, the pressure equalizing plate unit does not hinder the flow of resin when the commutator body is molded, and molding defects such as short shots can be suppressed.

  In order to solve the above-described problems, a commutator manufacturing method according to the present invention includes a plurality of conductive segments arranged in a cylindrical shape at intervals in the circumferential direction, and an insulating member inside the plurality of segments. And a pressure equalizing plate unit that is embedded in the commutator main body and is embedded in the commutator main body and connects segments of the same potential among the plurality of segments. The unit includes a plurality of pressure equalizing plates that connect segments having the same potential among the plurality of segments, and a unit main body that is formed of an insulating member and that integrates the plurality of pressure equalizing plates. A plurality of pressure equalizing plates formed integrally with the unit body, and a primary molding step for forming the pressure equalizing plate unit; A mold setting step of setting the plurality of segments so as to be cylindrical, and setting the pressure equalizing plate unit so that the pressure equalizing plate abuts on one end side of the rotation shaft in the plurality of segments, A secondary molding step of molding the commutator body by filling the resin inside the segment, and a welding step of electrically connecting the pressure equalizing plate and the segment by welding by irradiating a laser from above the pressure equalizing plate. It is characterized by having.

  By comprising in this way, it becomes possible to assemble | attach a pressure equalizing plate unit to a commutator main body simultaneously with a secondary shaping | molding process, and can shorten manufacturing time. Moreover, since positioning with respect to a segment can be performed when setting a pressure equalizing plate unit to a metal mold | die, a combination process can be simplified and a management process can be simplified. Further, since all the connecting portions of the pressure equalizing plate unit and the segment are arranged on one end side in the axial direction, laser welding from one side becomes possible, and the manufacturing time can be shortened. Therefore, it is possible to provide a commutator manufacturing method that can reduce the manufacturing cost of the commutator.

  According to the present invention, the winding operation of the equalizing wire can be eliminated, thereby shortening the manufacturing time, simplifying the operation of the winding machine, and simplifying the management process, thereby reducing the manufacturing cost of the commutator. Can do.

It is a partial cross section figure which shows the structure of the motor with a reduction gear in embodiment of this invention. It is a perspective view which shows the structure of the armature in embodiment of this invention. It is the perspective view which looked at the commutator in the embodiment of the present invention from the armature core side. It is the perspective view which looked at the commutator in the embodiment of the present invention from the worm gear reducer side. It is an external view which shows the structure of the pressure equalizing plate unit in embodiment of this invention. It is an external view which shows the structure of the some pressure equalization board in embodiment of this invention. It is an external view which shows the structure which combined the several equalizing plate in embodiment of this invention. It is the perspective view which looked at the commutator in the embodiment of the present invention from the worm gear reducer side. It is an expanded view of the armature in the embodiment of the present invention. It is a cross-sectional perspective view which shows the state in which the pressure equalizing plate unit in embodiment of this invention was set to the metal mold | die. It is a perspective view showing the state where a plurality of segments in the embodiment of the present invention are arranged in the shape of a cylinder. It is the top view which looked at arrangement | positioning of the pressure equalizing plate unit and segment in embodiment of this invention from the axial direction end on the opposite side to a riser. It is sectional drawing of the commutator in embodiment of this invention. It is a perspective view of a commutator which shows the direction of laser irradiation in the embodiment of the present invention.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Motor with reduction gear)
FIG. 1 is a partial cross-sectional view showing a configuration of a motor 1 with a speed reducer in an embodiment of the present invention.
As shown in the figure, a motor 1 with a speed reducer serves as a drive source for electrical components (for example, wipers, power windows, sunroofs, electric seats, etc.) mounted on a vehicle. And a worm gear reducer 4 connected to the rotating shaft 3 of the DC motor 2.

(DC motor)
In the DC motor 2, an armature 6 (not shown in FIG. 1) is rotatably disposed in a bottomed cylindrical yoke 5. Six tile-shaped permanent magnets (not shown) divided in the circumferential direction are fixed to the inner peripheral surface of the yoke 5 at equal intervals. These permanent magnets are formed using rare earth magnets such as neodymium sintered magnets.

(Worm gear reducer)
The worm gear reducer 4 is connected to the worm 8 housed in the gear housing 7 in addition to the gear housing 7, the worm wheel 9 meshing with the worm 8, and the output connected to the worm wheel 9 to output rotational power. Plate 11. The worm 8 is formed on the rotating shaft 3 supported on the inner walls of the bearing 10 and the gear housing 7, and rotates integrally with the rotation of the DC motor 2. The output plate 11 is driven by the rotational power transmitted from the worm 8 to the worm wheel 9.

(Armature)
FIG. 2 is a perspective view showing a configuration of the armature 6 in the embodiment of the present invention.
As shown in the figure, the armature 6 is fixed to the rotary shaft 3 on the bearing 10 side from the armature core 12, the armature coil 13 wound around the armature core 12, and the armature core 12. Commutator 14. The armature core 12 is formed, for example, by laminating a plurality of metal plates 15 in the axial direction.

  On the outer periphery of the metal plate 15, nine T-shaped teeth 16 are radially formed at equal intervals along the circumferential direction. By fitting and fixing a plurality of metal plates 15 to the rotary shaft 3 from the outside, a dovetail slot (not shown) is formed between adjacent teeth 16 on the outer periphery of the armature core 12. The slots extend along the axial direction, and nine slots are formed at equal intervals along the circumferential direction.

  Each tooth 16 is wound with an enamel-coated winding 24 (not shown). As a result, a plurality of armature coils 13 are formed on the outer periphery of the armature core 12. Further, after the winding 24 is wound around the tooth 16, the winding 24 is further locked to a riser 18 provided at one end of the nine segments 17 arranged on the outer peripheral surface of the commutator 14 on the armature core 12 side. That is, the direct current motor 2 has a so-called 6-pole 9-slot 9-segment three-phase (U-phase, V-phase, V-phase) in which the number of permanent magnets (magnetic poles) is set to 6, the number of slots is set to 9, and the number of segments 17 is set to 9. W phase) motor.

(Commutator)
Next, the commutator 14 will be described with reference to FIGS.
FIG. 3 is a perspective view of the commutator 14 viewed from the armature core 12 side.
FIG. 4 is a perspective view of the commutator 14 as viewed from the worm gear reducer 4 side.
As shown in FIGS. 3 and 4, the commutator 14 is embedded in the commutator body 19, a columnar commutator body 19, nine plate-like segments 17 arranged on the outer peripheral sliding surface of the commutator body 19, and the commutator body 19. And a pressure equalizing plate unit 22.

  The commutator main body 19 is formed of resin inside the segment 17, and nine segments 17 are fixed to the outer peripheral sliding surface of the commutator main body 19 at intervals in the circumferential direction. A through hole 20 into which the rotary shaft 3 can be press-fitted is formed at the radial center of the commutator body 19.

  A riser 18 is integrally formed at the center of the segment 17 on the armature core 12 side in the circumferential direction so as to be folded back toward the outer diameter side. The riser 18 is for locking the winding 24. The winding 24 is wound around the armature coil 13, is extended toward the commutator 14, and is locked to the riser 18. Then, by fixing the riser 18 to which the winding 24 is locked by fusing, the segment 17 and the armature coil 13 corresponding thereto are electrically connected.

  The plate material of the segment 17 is formed so that the dimension in the circumferential direction becomes narrower as the portion corresponding to the riser 18 extends toward the armature core 12 side. The plate material of the segment 17 is formed so that the tip extends from the portion where the dimension in the circumferential direction is narrowed to a constant width while maintaining a constant width. As a result, the segment 17 as a whole is in a state in which substantially semicircular depressions are formed between the risers 18 adjacent to each other in the circumferential direction at the end on the riser 18 side. By using the plate material having such a shape, the bending process can be facilitated and the amount of the winding 24 to be wound can be reduced.

  The riser 18 that is elongated to maintain a certain width is once folded back to the outer diameter side, and then folded back to the opposite side of the armature core 12 along the axial direction, so that it is formed in a substantially U shape. The tip of the folded riser 18 is formed in a substantially crank shape toward the inside in the radial direction. That is, as shown in FIG. 3, the tip of the riser 18 is radially inward through the outer diameter side step surface 18a and the inner diameter side step surface 18c extending in the plate thickness direction of the riser 18 and the outer side step surface 18a. The outer diameter side stepped surface 18b in the offset shape, the inner diameter side stepped surface 18d offset inward in the radial direction via the inner diameter side stepped surface 18c, and the radial dimension corresponding to the thickness of the plate material of the riser 18. A riser end face 18e is provided.

  A corner 18f is formed at the connection between the outer diameter side stepped surface 18a and the outer diameter side stepped surface 18b, and a corner 18g is formed at the connection between the inner diameter side stepped surface 18c and the inner diameter side stepped surface 18d. ing. Therefore, the winding 24 wound around the corner 18f and the corner 18g is reliably locked, so that the detachment of the winding 24 can be suppressed.

  Further, a corner 18h is formed at the connecting portion between the outer diameter side stepped surface 18b and the riser end surface 18e, and a corner 18i is formed at the connecting portion between the inner diameter stepped surface 18d and the riser end surface 18e. The tip of the riser 18 having the riser end face 18e with the corner 18h and the corner 18i at both ends maintains a constant size without becoming thinner toward the end. Therefore, the winding 24 is not loosened and easily detached from the riser 18 by being narrowed toward the end, and the winding 24 can be reliably locked.

In addition, a U-shaped concave portion 29 that is recessed toward the riser 18 side is formed by a notch at a substantially central portion in the circumferential direction on the side opposite to the riser 18 of the segment 17. The recess 29 positions the pressure equalizing plate unit 22 with respect to the segment 17.
In addition, three V-shaped anchors 32 (see FIG. 11) are formed inside the nine segments 17 in the longitudinal direction. The anchor 32 is for increasing the adhesion between the segment 17 and the commutator main body 19 and preventing peeling by the resin constituting the commutator main body 19 biting in.

  A pressure equalizing plate unit 22 is embedded in the end surface of the segment 17 opposite to the riser 18. In FIG. 4, since most of the pressure equalizing plate unit 22 is covered with the resin of the commutator main body 19, nine electrical connection portions 28 of the three pressure equalizing plates 21 constituting the pressure equalizing plate unit 22 are shown in total. Only.

FIG. 5 is an external view showing the configuration of the pressure equalizing plate unit 22.
As shown in the figure, the pressure equalizing plate unit 22 includes a unit body 31 having a substantially annular shape in plan view formed of a resin, and three pressure equalizing plates 21 manufactured by processing a copper plate material. The three pressure equalizing plates 21 (the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c) are formed integrally with the unit main body 31 with the centers thereof being overlapped in the axial direction. Here, parts other than the electrical connection portions 28 (28 a, 28 b, 28 c) of the pressure equalizing plate 21 are embedded in the unit main body 31. The electrical connection portions 28a, 28b, and 28c of each pressure equalizing plate 21 are arranged so as to extend radially from the unit main body 31 to nine locations.

(Equal pressure plate)
6A and 6B are external views showing the configuration of the pressure equalizing plate 21, wherein FIG. 6A shows the first pressure equalizing plate 21a, FIG. 6B shows the second pressure equalizing plate 21b, and FIG. The pressure equalizing plate 21c is shown.
The three pressure equalizing plates 21 are for short-circuiting the segments 17 having the same potential. These three pressure equalizing plates 21 are set to have different shapes in order to ensure insulation even when they are overlapped.
Hereinafter, the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c will be described with reference to FIG.

  As shown in FIG. 6A, the first pressure equalizing plate 21a is formed by punching a copper plate material (not shown) by press working. The first pressure equalizing plate 21a has a substantially annular shape in plan view, and is positioned on the same plane as the plate-like first annular portion 26a and the first annular portion 26a, and radially from the outer periphery of the first annular portion 26a. And three plate-like first electrical connection portions 28a extending outward.

  The first annular portion 26a is formed in an annular shape along the circumferential direction in order to short-circuit the segments 17 arranged along the commutator outer peripheral sliding surface. The first electrical connection portions 28 a are arranged at equal intervals along the circumferential direction, and extend radially outward in order to connect to the recesses 29 of the corresponding segments 17.

  As shown in FIG. 6B, the second pressure equalizing plate 21b is formed by punching out a copper plate material (not shown) by pressing and then bending a part of the copper plate material. The second pressure equalizing plate 21b has a substantially annular shape in plan view, and is arranged at equal intervals along the circumferential direction on the outer peripheral edge of the plate-like second annular portion 26b and the second annular portion 26b, and extends in the axial direction. Three second intermediate portions 27b and a second electrical connection portion 28b extending from a second tip portion 33b of the second intermediate portion 27b on a plane parallel to the second annular portion 26b are provided.

  The second annular portion 26b is formed in an annular shape along the circumferential direction in order to short-circuit the segments 17 arranged along the commutator outer peripheral sliding surface. The second intermediate portion 27b is formed by bending a plate-like member extending radially outward from the outer peripheral edge of the second annular portion 26b along the axial direction at the second base end portion 30b. . The second electrical connection portion 28b is formed by bending the plate-shaped member further outward in the radial direction at the second tip portion 33b of the second intermediate portion 27b arranged at equal intervals along the circumferential direction. ing. That is, the second electrical connection portion 28b extends from the second tip portion 33b of the second intermediate portion 27b and extends radially outward in order to connect to the concave portion 29 of the corresponding segment 17.

  As shown in FIG. 6C, the third pressure equalizing plate 21c is formed by punching out a copper plate material (not shown) by pressing and then bending a part of the copper plate material. The third pressure equalizing plate 21c is substantially annular in plan view, and is arranged at equal intervals along the circumferential direction on the outer peripheral edge of the plate-like third annular portion 26c and the third annular portion 26c, and extends in the axial direction. Three third intermediate portions 27c and a third electrical connection portion 28c extending from a third tip portion 33c of the third intermediate portion 27c on a plane parallel to the third annular portion 26c are provided.

  The third annular portion 26c is formed in an annular shape along the circumferential direction in order to short-circuit the segments 17 arranged along the commutator outer peripheral sliding surface. The third intermediate portion 27c is formed by bending a plate-like member extending radially outward from the outer peripheral edge of the third annular portion 26c along the axial direction at the third base end portion 30c. . The third electrical connection portion 28c is formed by bending the plate-shaped member further outward in the radial direction at the third tip portion 33c of the third intermediate portion 27c arranged at equal intervals along the circumferential direction. ing. That is, the third electrical connection portion 28 c extends from the third tip portion 33 c of the third intermediate portion 27 c and extends radially outward in order to connect to the concave portion 29 of the corresponding segment 17.

  Here, since it is necessary to secure insulation between the pressure equalizing plates 21, the heights of the first annular portion 26a, the second annular portion 26b, and the third annular portion 26c in the axial direction are different when they are overlapped. It is configured as follows. Therefore, the length Lb of the second intermediate portion 27b is at least the first uniform dimension so that the first annular portion 26a and the second annular portion 26b are spaced apart in the axial direction when they are overlapped. The thickness Lc of the third intermediate portion 27c is set to be larger than the thickness of the pressure plate 21a so that the second annular portion 26b and the third annular portion 26c are arranged at an interval in the axial direction when overlapped. The dimension of Lc is set larger than at least the length obtained by adding the thickness of the second pressure equalizing plate 21b to Lb.

FIG. 7 is an external view showing a configuration in which the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c are combined.
As shown in the drawing, the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c have a first electric connection portion 28a and a second electric connection with the direction along the rotation axis 3 as a central axis. The portion 28b and the third electrical connection portion 28c are overlapped so as to be positioned on the same plane. Here, the length Lb of the second intermediate portion 27b is at least larger than the thickness of the first pressure equalizing plate 21a, and the length Lc of the third intermediate portion 27c is at least Lb and the thickness of the second pressure equalizing plate 21b. It is set to be larger than the length including Therefore, the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c are arranged with an interval in the axial direction.

As shown in the figure, the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c are composed of a first electrical connection portion 28a, a second electrical connection portion 28b, and a third electrical connection. A total of nine electrical connection portions 28 made up of the portions 28c are combined so as to be arranged at equal intervals in the circumferential direction. That is, the angle formed by the electrical connection portions 28 adjacent to each other is 40 degrees.

FIG. 8 is a perspective view of the commutator main body 19, the unit main body 31 is indicated by a two-dot chain line, and the commutator 14 is viewed from the worm gear reducer 4 side.
As shown in the figure, the pressure equalizing plate unit 22 is disposed at one end in the axial direction of the segment 17, and the nine electrical connection portions 28 are fixed so as to fit into the concave portions 29 of the corresponding segment 17. As a result, the three segments 17 having the same potential and the pressure equalizing plate 21 are connected and electrically connected. On the other hand, the pressure equalizing plates 21 that connect the segments other than the segment having the same potential are arranged with an interval therebetween, and thus are insulated from each other.

FIG. 9 is a development view of the armature 6.
Here, as described above, when the pressure equalizing plate unit 22 and the segment 17 are connected and the segments having the same potential are electrically connected to each other, the current supplied from the brush that is in sliding contact with the segment 17 passes through the pressure equalizing plate 21. Are supplied to the segment 17 having the same potential. The current supplied to the segments 17 is further supplied to the corresponding armature coils 13 through the windings 24.

  A specific flow of current supply in the armature 6 will be described below with reference to FIG. Since the DC motor 2 in the present embodiment is a so-called 6-pole 9-slot 9-segment three-phase motor, as shown by a thick line in FIG. The fourth segment 17 and the seventh segment 17 are three. Here, the segments 17 having the same potential are short-circuited by the pressure equalizing plate 21, and every two segments 17 are short-circuited by the pressure equalizing plate 21 as shown in FIG.

  More specifically, as shown by a thick line in FIG. 9, when the winding start end 24a starts to be wound from the seventh segment 17, the winding 24 has a first armature coil 13a, a second armature coil 13b, a third The armature coil 13c is formed and reaches the winding end 24b. In other words, the current supplied by the brush slidably contacting one of the first segment 17, the fourth segment 17, and the seventh segment 17 short-circuited by the pressure equalizing plate 21 is also equalized to the other two segments. It is supplied via the pressure plate 21. Therefore, a magnetic field is generated simultaneously by supplying currents in phase to the three armature coils 13 (first armature coil 13a, second armature coil 13b, and third armature coil 13c) connected in series. The rotating shaft is rotated by a magnetic attractive force / repulsive force generated between the magnetic force of the magnetic field and the permanent magnet.

(Manufacturing method of commutator)
Next, a method for manufacturing the commutator 14 will be described.
First, as shown in FIG. 7, the first pressure equalizing plate 21a, the second pressure equalizing plate 21b, and the third pressure equalizing plate 21c are respectively coaxial with the centers of the first annular portion 26a, the second annular portion 26b, and the third annular portion 26c. All the first electrical connection portions 28a, the second electrical connection portions 28b, and the third electrical connection portions 28c are arranged so as to extend radially outward at equal intervals in the circumferential direction. . Then, the plurality of pressure equalizing plates 21 that are overlaid are set using a positioning mechanism or the like at a predetermined position in the cavity of a mold (not shown) in an opened state. Here, the tips of the first electrical connection portion 28a, the second electrical connection portion 28b, and the third electrical connection portion 28c are exposed radially outward from the unit main body 31 made of resin. It is set in the mold so as to be located outside the cavity filled with the resin.

Next, the mold is closed and, for example, the resin melted by the screw pressure of an injection molding machine is filled. Here, the resin enters the space between the pressure equalizing plates, and when the resin is cured, the plurality of pressure equalizing plates 21 and the unit main body 31 are integrally formed in the mold. In addition, the mold is configured so that the inner peripheral side of the first annular portion 26a, the second annular portion 26b, and the third annular portion 26c in the pressure equalizing plate unit 22 is not filled with resin. After the resin is cured and molding is completed, the mold is opened, and the pressure equalizing plate unit 22 shown in FIG. 5 is taken out from the molding machine by a take-out mechanism such as an ejector pin.
In this way, the unit main body 31 made of resin covers the annular portion 26 of the pressure equalizing plate 21, the intermediate portion 27, and a part on the radially inner side of the electrical connection portion 28, while being electrically connected. The radially outer end of the portion 28 is molded so as to be exposed from the unit body 31, and the pressure equalizing plate unit 22 is completed (primary molding step).

Next, the setting of the pressure equalizing plate unit 22 and the segment 17 to the mold will be described with reference to FIGS.
FIG. 10 is a cross-sectional perspective view showing a state where the pressure equalizing plate unit 22 completed by the primary molding is set in a mold. FIG. 11 is a perspective view showing a state in which a plurality of segments 17 are arranged in a cylindrical shape. FIG. 12 is a plan view of the commutator body 19, the unit body 31 is indicated by a two-dot chain line, and the arrangement of the pressure equalizing plate unit 22 and the segment 17 is viewed from one axial end opposite to the riser 18.
As shown in FIGS. 10 to 12, first, the pressure equalizing plate unit 22 manufactured by the primary molding process is set at one end of the cavity in the opened mold by using a positioning mechanism or the like. Here, the pressure equalizing plate unit 22 is set so that the electrical connection portion 28 is positioned on the end face side on one end side opposite to the gate position where the resin is filled in the axial direction.

  Next, as shown in FIG. 10, a plurality of segments 17 are set in a cylindrical shape as shown in FIG. 11 on the outer periphery of the cavity in the mold in which the pressure equalizing plate unit 22 is set. Here, as shown in FIG. 12, a recess 29 is provided at one end of each of the plurality of segments 17 at a position corresponding to the riser 18 at the center in the circumferential direction. The plurality of segments 17 are set on one end side in the direction of the rotary shaft 3 in the cavity so that the concave portions 29 of the segments corresponding to the electrical connection portions 28 fit in the mold. At this time, the concave portion 29 and the electrical connection portion 28 are fitted to each other, whereby the segment 17 is positioned in the die (die setting step).

Next, molding of the commutator main body 19 will be described with reference to FIG.
13 is a cross-sectional view of the commutator 14 at the position of the arrow in FIG.
After the pressure equalizing plate unit 22 and the plurality of segments 17 are set in the mold in the mold setting step, the mold is closed and, for example, the resin melted in the mold is filled with the screw pressure of an injection molding machine, thereby the commutator main body. 19 is formed. Here, as shown in FIG. 13, the resin is filled from one end where the pressure equalizing plate unit 22 is located and a gate located on the opposite side in the axial direction. Therefore, the resin can be evenly distributed in the mold without hindering the flow of the resin by the pressure equalizing plate unit 22. Then, by curing the resin, the pressure equalizing plate unit 22, the plurality of segments 17, and the commutator main body 19 can be integrally formed.

Here, the commutator main body 19 is formed so as to cover the unit main body 31, the annular portion 26, the intermediate portion 27, and a part of the electrical connection portion 28 on the end surface side. In other words, as shown in FIG. 13, the resin filled from the gate passes around the pressure equalizing plate unit 22 and further goes to the end face side. Therefore, the unit main body 31 and a part of the electrical connection portion 28 receive both the resin pressure due to the resin that wraps around the end surface side and the pressure due to the mold closing, and the end of the electrical connection portion 28 on the radially outer side. The part is pressed against the recess 29 of the segment 17.
Then, after the resin is cured and molding is completed, the mold is opened, and the commutator 14 in which the commutator main body 19, the pressure equalizing plate unit 22 and the segment 17 are integrally molded by a take-out mechanism such as an ejector pin is taken out from the molding machine (secondary Molding process).
Since the anchor 32 (see FIGS. 11 and 12) is formed inside the segment 17, the resin flows into the V-groove-shaped anchor 32 when the resin is filled, and the anchor 32 is converted into the resin in a state where the resin is cured. The biting force increases the adhesion between the segment 17 and the commutator main body 19.

Next, laser welding will be described with reference to FIG.
FIG. 14 is a perspective view of the commutator 14 showing the direction of laser irradiation.
As shown in the figure, the commutator 14 manufactured by the secondary molding process is welded by irradiating a laser beam to the joint 34 where the electrical connection 28 and the segment 17 abut. The segment 17 and the pressure equalizing plate 21 are electrically connected by this welding process. At this time, as shown in FIG. 14, the laser beam is irradiated in the direction of the arrow toward the end surface of the commutator 14 on the opposite side of the riser 18 where all the joint portions 34 are located. Therefore, welding of all the joining parts 34 is performed only by laser irradiation from one direction (welding process).

As described above, the commutator 14 according to the present embodiment includes the pressure equalizing plate unit 22 that is embedded in the commutator body 19 and connects the segments 17 having the same potential among the plurality of segments 17.
Therefore, it is possible to eliminate the winding work of the equalizing wire, so that it is possible to provide a commutator that reduces the manufacturing cost by shortening the manufacturing time, simplifying the operation of the winding machine, and simplifying the management process. it can. Further, the pressure equalizing plate unit 22 is not disposed on the outer side in the axial direction than the commutator body 19, and the axial length of the commutator can be suppressed.

The commutator 14 is formed so that the unit main body 31 covers the annular portion 26 and the intermediate portion 27.
Therefore, since the space between the pressure equalizing plates 21 where air bubbles are likely to be generated in the molding process of the commutator body 19 is covered in advance by the unit body 31, it is possible to suppress the resin filling failure in the molding process of the commutator body 19.

In the commutator 14, the unit main body 31 is disposed on one end side in the axial direction of the rotation shaft 3 of the segment 17.
Therefore, the pressure equalizing plate unit 22 can be easily assembled to the commutator 14.

Further, the commutator 14 is formed with a concave portion 29 that can be fitted to the electrical connection portion 28 at one end of the segment 17 in the axial direction.
Therefore, since the electrical connection portion 28 and the concave portion 29 are fitted to each other on one end side in the axial direction, it is possible to irradiate all the joint portions 34 from one direction during laser welding, thereby simplifying the welding operation. it can.

Further, the commutator body 19 is formed so as to cover the unit body 31 and a part of the electrical connection portion 28 from the outside in the axial direction by filling the inside of the plurality of segments 17 with resin.
Accordingly, the resin wraps around the outside in the axial direction, and the electrical connection portion 28 is pressed against the concave portion 29 of the segment 17 through the unit body 31 by the resin pressure and the mold pressure. Therefore, the segment 17 and the pressure equalizing plate 21 can be reliably brought into contact with each other.

Further, in the commutator 14, the annular portions 26 of the plurality of pressure equalizing plates 21 are arranged coaxially at intervals in the axial direction of the rotary shaft 3, and the electrical connection portions 28 are on the same plane. It is formed to become.
Therefore, since the pressure equalizing plates are arranged at intervals, a short circuit can be prevented.

The commutator main body 19 is formed by filling the inside of the plurality of segments 17 with a resin. An inlet of the resin is set on one end side in the axial direction of the rotation shaft 3 in the plurality of segments 17. The pressure equalizing plate unit 22 is arranged on the other axial end side.
Therefore, the pressure equalizing plate unit 22 does not hinder the flow of the resin when the commutator body 19 is molded, and molding defects such as short shots can be suppressed.

Moreover, the manufacturing method of the commutator 14 includes a primary molding process for forming the pressure equalizing plate unit 22, a mold setting process for setting the segment 17 and the pressure equalizing plate unit 22 in the mold, and a secondary molding process for molding the commutator body. And a welding process.
Therefore, the pressure equalizing plate unit 22 can be assembled to the commutator main body 19 simultaneously with the secondary molding step, and the manufacturing time can be shortened. Moreover, since positioning with respect to the segment 17 can be performed when setting the pressure equalizing plate unit 22 in a metal mold | die, a combination process can be simplified and a management process can be simplified. Further, since all the joint portions 34 of the pressure equalizing plate unit 22 and the segment 17 are arranged on one end side in the axial direction, laser welding from one side is possible, and the manufacturing time can be shortened. Therefore, the manufacturing method of the commutator which suppressed manufacturing cost can be provided.

  The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the case where injection molding is performed in both primary molding and secondary molding has been described. However, the present invention is not limited to this. For example, molding may be performed by a method such as compression molding, or different molding methods may be used for primary molding and secondary molding.

For example, in the above-described embodiment, the case where the segment 17 is set in the mold after the pressure equalizing plate unit 22 is set in the mold has been described. However, the present invention is not limited to this, and a method of setting the pressure equalizing plate unit 22 in the mold after setting the segment 17 in the mold may be used.

  For example, in the above-described embodiment, the case where the welding process is performed after the secondary forming process has been described. However, it is not restricted to this, You may perform a secondary shaping | molding process after a welding process.

For example, in the above-described embodiment, the case of laser welding has been described. However, the present invention is not limited to this, and welding may be performed by other methods such as arc welding or soldering.

For example, in the above-described embodiment, the case of a pressure equalizing plate using a copper plate material has been described. However, the present invention is not limited to this, and a conductive material such as a tin-plated plate may be used.

DESCRIPTION OF SYMBOLS 1 ... Motor with reduction gear 3 ... Rotary shaft 4 ... Worm gear reduction gear (deceleration mechanism)
12 ... Armature core 13 ... Armature coil 13a ... First armature coil (armature coil)
13b ... 2nd armature coil (armature coil)
13c ... Third armature coil (armature coil)
14 ... Commuter 17 ... Segment 18 ... Riser 19 ... Commutator body 21 ... Pressure equalizing plate 21a ... First pressure equalizing plate (equal pressure plate)
21b ... 2nd pressure equalizing plate (pressure equalizing plate)
21c ... Third pressure equalizing plate (pressure equalizing plate)
22 ... pressure equalizing plate unit 26 ... annular portion 26a ... first annular portion (annular portion)
26b ... second annular part (annular part)
26c ... 3rd annular part (annular part)
27 ... intermediate portion 27b ... second intermediate portion (intermediate portion)
27c ... 3rd intermediate part (intermediate part)
28: Electrical connection 28a: First electrical connection (electrical connection)
28b ... 2nd electrical connection part (electrical connection part)
28c ... 3rd electrical connection part (electrical connection part)
29 ... Recess 31 ... Unit body

Claims (9)

A plurality of conductive segments arranged in a cylindrical shape at intervals in the circumferential direction;
A commutator body that is molded with an insulating member inside the plurality of segments and is fitted and fixed to a rotation shaft;
A pressure equalizing plate unit that is embedded in the commutator body and connects segments having the same potential among the plurality of segments, and
With
The pressure equalizing plate unit is
Among the plurality of segments, a plurality of pressure equalizing plates that connect segments having the same potential,
A unit main body formed of an insulating member and integrating the plurality of pressure equalizing plates;
A commutator characterized by comprising: The pressure equalizing plate is
An annular portion having a direction along the rotation axis as a central axis;
An intermediate portion extending from the annular portion so as to follow the axial direction of the rotation shaft;
An electrical connection extending radially outward from the intermediate portion and connected to the segment;
Including
The commutator according to claim 1, wherein the unit main body is formed so as to cover the annular portion and the intermediate portion.   The commutator according to claim 2, wherein the unit main body is disposed on one end side in the axial direction of the rotation shaft of the segment.   The commutator according to claim 3, wherein a concave portion that can be fitted to the electrical connection portion is formed at one end of the segment in the axial direction. The commutator body is molded by filling a resin inside the plurality of segments,
The commutator according to claim 3 or 4, wherein the commutator main body is formed so as to cover the unit main body and a part of the electrical connection portion from outside in the axial direction. The commutator body is molded by filling a resin inside the plurality of segments,
The plurality of pressure equalizing plates are formed such that each of the annular portions is coaxially arranged with an interval in the axial direction of the rotation shaft, and each of the electrical connection portions is on the same plane. The commutator as described in any one of Claims 2-4 characterized by the above-mentioned. The commutator body is molded by filling a resin inside the plurality of segments,
The inflow port of the resin is set on one axial end side of the rotation shaft in the plurality of segments, and the pressure equalizing plate unit is disposed on the other axial end side of the rotation shaft. The commutator as described in any one of Claims 1-5. The commutator according to any one of claims 1 to 7,
A rotating shaft that rotatably supports the commutator;
An armature core provided on the rotating shaft adjacent to the commutator and wound with an armature coil;
A speed reduction mechanism coupled to the rotating shaft;
A motor with a speed reducer, characterized by comprising: A plurality of conductive segments arranged in a cylindrical shape at intervals in the circumferential direction;
A commutator body that is molded with an insulating member inside the plurality of segments and is fitted and fixed to a rotation shaft;
A pressure equalizing plate unit that is embedded in the commutator body and connects segments having the same potential among the plurality of segments, and
With
The pressure equalizing plate unit is
Among the plurality of segments, a plurality of pressure equalizing plates that connect segments having the same potential,
A method of manufacturing a commutator comprising a unit main body formed by an insulating member and integrating a plurality of the pressure equalizing plates,
A plurality of the pressure equalizing plates are integrally formed by the unit main body, and a primary forming step of forming the pressure equalizing plate unit;
A mold setting step of setting a plurality of the segments in a mold so as to form a cylindrical shape, and setting the pressure equalizing plate unit so that the pressure equalizing plate abuts on one end side of the rotation shaft in the plurality of segments. When,
A secondary molding step of molding the commutator body by filling a resin inside the plurality of segments;
A welding step in which laser is irradiated from above the pressure equalizing plate to electrically connect the pressure equalizing plate and the segment by welding;
A method of manufacturing a commutator, comprising:

Images