JPH08126257A - Commutator of dynamo-electric machine, and its manufacture - Google Patents

Abstract

PURPOSE: To make a commutator without executing the undercut processing by removing a coupling part after inserting collectively cylindrical commutator pieces being arranged apart in the circumferential direction, with one end each connected at the coupling part so as to mold insulated resin, and fixing each resin commutator piece integrally into the outside periphery of the resin part. CONSTITUTION: A commutator piece being made by bending and rounding a die-cut plate where axial one end each is connected with one another into cylindrical shape is inserted into a mold so as to mold an insulated resin part 3, and several commutator pieces 2 are fixed apart integrally at the outside periphery of the insulated resin part 3, and then the coupling part is removed, and each piece 2 is separated electrically from one another. Each commutator piece 2 is fixed to the outside periphery of the insulated resin part 3 firmly by inner claws 22 and 23. Hereby, the commutator piece 2 can be manufactured without executing the least undercut which were being performed conventionally, and the productivity can be raised and the production cost lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commutator for a rotary electric machine and a method for manufacturing the commutator.

[0002]

2. Description of the Related Art As a conventional commutator for a rotating electric machine and a method for manufacturing the same, there is one described in JP-A-4-58742. First, as shown in the perspective view of FIG.
The plate material punched out leaving 21 is bent into a cylindrical shape, and resin is injected into the inside of the cylindrical body 110 to form the insulating resin portion 103 as shown in FIG. After that, the cylinder 11
The commutator 101 is manufactured by cutting the undercut groove 104 from the outer peripheral surface of No. 0 and forming the plate material into a plurality of commutator pieces 102 electrically separated from each other.

[0003]

However, the above commutator and the manufacturing method thereof have a problem that undercut processing is required. That is, it is necessary to cut each undercut groove along the axis at a constant depth by the number of commutator pieces to make each commutator piece independent, and in many cases, finishing treatment for removing burrs generated at that time is also required. Therefore, there is a problem that it takes man-hours and the cost is also reflected.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to manufacture a commutator for a rotary electric machine without performing any undercut processing.

[0005]

A commutator for a rotating electric machine according to the present invention comprises a cylindrical insulating resin portion and a plurality of insulating resin portions arranged circumferentially at regular intervals on an outer peripheral surface of the insulating resin portion. In a commutator of a rotary electric machine having a commutator piece, one end of each commutator piece is connected by a connecting portion and arranged at intervals in the circumferential direction, and one end in the axial direction forms the connecting portion. After inserting a cylindrical commutator piece as a whole to mold the insulating resin portion and integrally fix each commutator piece to the outer peripheral surface of the insulating resin portion, remove the connecting portion. It is characterized in that each of the commutator pieces is separated at intervals.

The commutator for a rotary electric machine according to the present invention is manufactured by a manufacturing method characterized by comprising a punching step, a bending step, a molding step and a separating step. Here, in the punching step, a flat plate of a good conductor is punched from the other end in the direction of one end in a slit shape at a predetermined interval except for one end portion, one end is connected to each one end portion, and the slits are arranged in parallel. A stamped plate having a plurality of commutator pieces is formed. Next, in the bending step, the punched plate is bent into a cylindrical shape, and the one end portion becomes one end in the axial direction to form a cylindrical body in which the commutator pieces are circumferentially arranged at intervals. Then, in the molding step, the cylindrical body is inserted into a molding die to mold a resin, and a cylindrical insulating resin portion in which the commutator pieces are circumferentially arranged and fixed on the outer peripheral surface is molded. It Finally, in the separating step, the commutator pieces are separated by removing the one end portion to form electrically independent commutator pieces.

In the molding step of such a manufacturing method, the inner peripheral surface forming the cylindrical cavity has a recess for accommodating each of the commutator pieces, and a space between the recesses for accommodating two adjacent commutator pieces is provided. It is even better to use a mold that is convex toward the center. In this way, the resulting commutator will
The outer peripheral surface of the insulating resin portion exposed between two adjacent commutator pieces is located at a position lower than the exposed outer peripheral surface of the commutator piece, and a groove is formed between the adjacent commutator pieces. Has become.

Further, the commutator piece is composed of a commutator piece body, a hook portion and an inner claw, and in a bending step, the hook portion is bent in the centrifugal direction and the inner claw is bent in the center direction. The inner claw is embedded and fixed in the insulating resin portion.

[0009]

In the commutator of the rotating electric machine of the present invention, the commutator pieces are connected at the connecting portion and are arranged at equal intervals in the process of manufacturing the commutator. The insulating resin portion can be molded and solidified inside the child while the children are arranged at equal intervals in the circumferential direction. After that,
By removing the connecting portion, each commutator can be electrically independent, and a commutator for a rotary electric machine can be manufactured without performing any undercut processing.

In the commutator having the groove between the adjacent commutator pieces, since the outer peripheral surface of the insulating resin portion is located lower than the outer peripheral surface of the commutator piece, the brush is the outer peripheral surface of the insulating resin portion. Do not rub Further, if the inner claw is embedded in the insulating resin portion, each commutator piece is more firmly fixed to the insulating resin portion.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows a cross-sectional view of a commutator of a rotating electric machine according to Embodiment 1 of the present invention as viewed in the axial direction. Commutator 1 of the present invention
Has a hollow cylindrical insulating resin portion 3 and a plurality of commutator pieces 2 arranged on the outer peripheral surface thereof at regular intervals at intervals in the circumferential direction. From one end of each commutator piece 2 on the armature winding side, a hook portion 21 formed of a plate material continuous from the main body portion 20 of the commutator piece 2 is connected to an armature winding (not shown) and radially outward. Standing up. The outer peripheral portion of the insulating resin portion 3 fills the gap between the commutator pieces 2 to ensure complete insulation between the commutator pieces 2 and to firmly hold each commutator piece so as to withstand a high centrifugal force. Holds 2.

The commutator 1 is attached to the rotating armature 100 to function as shown in FIG. The commutator piece 2 arranged on the outer peripheral portion of the commutator 1 has inner claws 22 and 23 embedded in the insulating resin portion 3 at both axial end portions of the main body portion 20. The inner claws 22 are plate materials that are continuous from the main body portion 20 of the commutator piece 2, and two pieces from both sides of the root of the hook portion 21 rise to the axial center side, are bent inward in the axial direction, and are embedded in the insulating resin portion 3. ing. On the other hand, the inner claw 23 is also formed of a plate material that is continuous from the main body portion 20 of the commutator piece 2, and rises in the axial direction from one end on the side opposite to the hook portion 21 so as to face the inner claw 22 in the axial direction. It is bent to be embedded in the insulating resin portion 3. Inner claw 2 like this
2, 23, each commutator piece 2 is firmly fixed to the insulating resin portion 3
It is fixed to the outer circumference of.

On the other hand, the hook portion 21 is the commutator piece main body portion 2.
It stands up from one end of the armature winding side of 0, is connected to the armature winding, and supplies power to this. The commutator 1 is formed by bending a punched plate whose one end in the axial direction is connected by a connecting portion and rounding it into a cylindrical shape, and inserting the cylindrical commutator piece into a molding die to mold the insulating resin portion 3. After the respective commutator pieces 2 are integrally fixed to the outer peripheral surface of the insulating resin portion 3 with a space therebetween, the connecting portions are removed at once and the commutator pieces 2 are electrically separated.

Commutator 1 of the rotating electric machine of the present invention as described above
Is manufactured by a manufacturing method characterized by comprising a punching process, a bending process, a molding process and a separating process.
Hereinafter, this manufacturing method will be described with reference to FIGS.
First, as shown in FIG. 3A, a punching process is performed.
That is, a copper plate material serving as a flat plate of a good conductor is punched from the other end in the upper part of the drawing toward one end in the lower part of the drawing at a predetermined interval except for one end part in the lower part of the drawing. That is, by punching out the slit 25 with the connecting portion 24 left at one end, a punching plate having a plurality of commutator pieces 2 arranged in parallel at regular intervals and formed in the slit 25 has a comb-teeth shape. Form.

At this time, the main body portion 20 of the commutator piece 2 forms a rectangular strip, and one end thereof is integrally connected to the adjacent commutator piece 2 by the strip-shaped connecting portion 24. At the other end of the commutator piece 2, a member having a constant width, which later becomes the hook portion 21, extends along the center line thereof, and on both sides thereof, members which will become inner claws later are formed. It extends shorter than the hook portion 21. Therefore, the other end side of the punched plate becomes one step thinner at the portion where the main body portion 20 of the commutator piece 2 moves to the base of the hook portion 21 and the inner claw 22,
Furthermore, at the end of the inner claw 22, the hook portion 2 becomes thinner.
The width becomes 1 itself, and it becomes thinner in two steps and reaches the end.

Next, as shown in FIG. 3 (b), the inner claws 22 on the hook portion 21 side are cut and raised from both sides of each hook portion 21 at a substantially right angle. Similarly, from the connecting portion 24 side, the commutator piece 2
The inner claw 23 is cut and raised at a substantially right angle along the center line of the main body portion 20 of. At this time, the cut-and-raised depth of the inner claw 23 is
Cut up so as to overlap the cut depth of the slit 25. Although the connecting portions 24 are zigzag due to the cut and raised, the commutator pieces 2 are still held in parallel.
The above-mentioned cut-and-raised work is processed in one step using a press board.

Next, a bending step is performed. That is, the punched plate described above is bent and rolled into a cylindrical shape as shown in FIG. That is, the connecting portion 24 serves as one end in the axial direction and the hook portion 21 serves as the other end, and the commutator pieces 2 are arranged at equal intervals in the circumferential direction (cylindrical commutator piece body).
10 is formed by rolling a punched plate. At this time, each commutator piece 2 is also bent uniformly so as to have a curvature along the outer circumference of the cylindrical body 10.

Then, as shown in FIGS. 4 (a) and 4 (b), the inner claws 22 and 23 cut and raised in the axial direction are bent inward in the axial direction to prepare for the next molding of the insulating resin portion.
Next, a molding step of molding the insulating resin portion 3 is performed. That is, the cylindrical body 10 having the inner pawls 22 and 23 molded as described above is inserted into a cylindrical molding die, and each commutator piece 2 is inserted.
The outer peripheral surface of the main body portion 20 is brought into close contact with the inner peripheral surface of the molding die. Then, while forming a space of a joint with the rotary armature shaft with a nest, a thermoplastic resin having excellent insulating properties is injected to mold the insulating resin part 3 as shown in FIG. 4 (c). To do.

Then, after the insulating resin portion 3 is solidified, as shown in FIG.
As shown in (c), each hook portion 21 is bent toward the outer peripheral side of the armature 1 to prepare for connection with an armature winding (not shown). At the same time, a separation step of removing the connecting portion 24 is performed. That is, the connecting portion 2 protruding from the insulating resin portion 3 in the axial direction
4 is cut and removed in one step. By doing so, each commutator piece 2 can electrically function independently as a commutator 1 without undercutting.

The commutator 1 thus formed is mounted by engaging the serrated inner peripheral surface 30 of the insulating resin portion 3 with the shaft of the rotating armature 100, and the hook portion 21 and resistance welding with the armature winding. It is connected (fused) by and becomes a commutator of the rotating electric machine. In this way, the commutator 1 is completed without undercutting, so the number of processing steps can be reduced, and as a result, the processing cost of the commutator can be reduced, and a rotary electric machine with more price competitiveness can be provided. become. In addition, the parts that were undercut in the past to become chips mixed with resin powder are recovered with slit-shaped sheet metal material, so some effects can be expected for material recycling, and both environment and cost can be expected. Contribute to.

Further, the inner claws are fixed to the insulating resin portion at both ends of the commutator piece, and the insulating resin is filled between adjacent commutator pieces 2. For this reason, the commutator piece 2 can be held more firmly, and there is an effect that it is possible to endure a larger acceleration such as a centrifugal force. (Embodiment 2) In Embodiment 1, since the inner peripheral surface of the female die used in the molding step has a circular cross section, the outer peripheral surface of the insulating resin portion 3 is the main body portion of the commutator piece 2 as shown in FIG. It coincides with the outer peripheral surface of 20. This is desirable from the viewpoint of preventing abrasion of the brush that rubs against the commutator 1, but there is a concern that resin pieces or resin powder separated from the outer peripheral surface of the insulating resin portion 3 will intervene between the brush and the commutator piece 2. Not without.

Therefore, as shown in FIG. 5, a groove for accommodating the main body portion 20 of each commutator piece 2 is formed on the inner peripheral surface forming the cylindrical cavity of the molding die 4 used in the step of molding the above-mentioned insulating resin portion. Two adjacent commutator pieces 2 provided with a groove-shaped recess 41
Between these recesses 41 for accommodating the main body portion 20, there is provided a projection 42 that is convex toward the center. When the insulating resin portion 3 is formed in this manner, as shown in FIG. 6, the body portion 20 of the commutator piece 2 is formed on the outermost peripheral surface of the armature 1.
The outer peripheral surface of the insulating resin portion 3 is located at the position where the outer peripheral surface of the insulating resin portion 3 is located, and the outer peripheral surface of the insulating resin portion 3 is located at a position lower than the outer peripheral surface of the insulating resin portion 3. In this case, the brush does not come into contact with the outer peripheral surface of the insulating resin portion 3, so that contact failure due to the resin powder can be prevented.

By the way, it is not necessary to form the concave portion 31 in the portion which does not come into contact with the brush. Therefore, as shown in FIG. 7, the concave portion 31 is formed only in the portion that comes into contact with the brush, and the insulating resin portion 3 is filled up to the same outer peripheral surface as the surface of the commutator piece 2 on the side of the hook portion 21 that does not come into contact with the brush. The centrifugal resistance can be increased. (Embodiment 3) In the above embodiments, when the punched plate was made, the connecting portion 24 was provided only at one end opposite to the hook portion 21 to connect the respective commutator pieces 2 integrally. It is also possible to provide a section.

That is, as shown in FIG. 8, one end of the commutator piece 2 is connected by the connecting portion 24 as in the previous embodiment, and the other end, that is, the tip of each hook portion 21 is also connected by the connecting portion 26.
It is also possible to manufacture the commutator 1 by punching the punching plates integrally connected with each other. In this case, since the commutator piece 2 is held by the connecting portion 26 on the other end side, that is, on the hook portion 21 side in the subsequent process, it is possible to perform processing without shaking, thereby improving the processing accuracy and fixing. It is possible to simplify the ingredients.

The connecting portion 26 may be removed by cutting off the tip of the hook portion 21 in one step after the insulating resin portion 3 is molded as in the previous embodiment. In addition to that, from the punched plate connected only by the connecting portion 26 on the hook portion 21 side,
It is possible to manufacture the commutator 1 by a manufacturing method substantially similar to those of these examples.

[0026]

As described above in detail, according to the commutator of the rotating electric machine and the method of manufacturing the same of the present invention, it is possible to manufacture the commutator without performing the undercut processing which has been conventionally performed. Therefore, there is an effect that the productivity of the commutator of the rotary electric machine is greatly increased and the production cost can be reduced.

Further, in a commutator having a groove formed between adjacent commutator pieces, the brush does not rub the outer peripheral surface of the insulating resin portion, so that resin powder or debris slides between the brush and the commutator. It is possible to prevent problems caused by adhesion to the surface. Also,
By embedding the inner claws in the insulating resin part and firmly fixing each commutator piece, the resin also enters the gap between each commutator piece to enhance the adhesiveness and withstand a higher centrifugal force. A commutator can be manufactured.

Note that if added intentionally, chips due to undercut do not come out, and punching slits and cut-off joints in the form of metal pieces are collected, so a material recycling effect can be expected.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a commutator according to a first exemplary embodiment of the present invention as viewed in the axial direction.

FIG. 2 is a half cross-sectional view of a commutator attached to a rotating armature.

FIG. 3 is a process drawing showing a first half of a process for manufacturing a commutator of the present invention. (A) is a plan view showing a punching plate of a commutator piece and a connecting portion, (b) is a plan view showing a punching plate in which inner claws are cut and raised, and (c) is a cylindrical body obtained by rolling the punching plate. It is the figure seen from the axial direction.

FIG. 4 is a process drawing showing the latter half of the manufacturing process of the commutator of the present invention. (A) is a cross-sectional view of a step of bending an inner claw at one end from a cylinder, (b) is a cross-sectional view of a step of bending the other inner claw from a cylinder, and (c) is a molding step and a separation step. It is sectional drawing explaining.

FIG. 5 is an end view of a molding die in which a tubular body of Example 2 is inserted.

FIG. 6 is a sectional view of a commutator according to a second exemplary embodiment of the present invention as viewed in the axial direction.

FIG. 7 is a sectional view taken along the axis of a commutator according to a second embodiment of the present invention.

FIG. 8 is a plan view of a punching plate according to Example 3 of the present invention.

FIG. 9 is a perspective view of a commutator in a conventional manufacturing process.

FIG. 10 is a cross-sectional view of a conventional commutator as viewed from the axial direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commutator 10 Cylindrical body 2 Commutator piece 20 Body part 21 Hook part 22 Inner claw (hook part side) 23 Inner claw (terminal side) 24 Connecting part 25 Slit 26 Connecting part 3 Insulating resin part 30 Inner peripheral surface 31 Recess 4 Mold 41 Recess 42 Convex 100 Rotating armature 101 Commutator 102 Commutator piece 103 Insulating resin part 104 Undercut groove 110 Cylindrical body 121 Hook part

Claims (6)

[Claims] 1. A commutator for a rotary electric machine, comprising: a cylindrical insulating resin portion; and a plurality of commutator pieces arranged on the outer peripheral surface of the insulating resin portion at regular intervals at intervals in the circumferential direction, One end of each of the commutator pieces is connected by a connecting portion and arranged at intervals in the circumferential direction, and one end in the axial direction forms the connecting portion and a cylindrical commutator piece body is inserted as a whole. After molding the insulating resin portion and integrally fixing each of the commutator pieces to the outer peripheral surface of the insulating resin portion, the connecting portion is removed to separate the commutator pieces at intervals. A commutator for a rotating electric machine characterized by being present. 2. An outer peripheral surface of the insulating resin portion exposed between two adjacent commutator pieces is lower than an exposed outer peripheral surface of the commutator piece, and the adjacent commutator pieces are adjacent to each other. The commutator for a rotating electric machine according to claim 1, wherein a gap is provided between the commutators. 3. The commutator for a rotary electric machine according to claim 1, wherein each of the commutators has at least one inner claw, and the inner claw is embedded in the insulating resin portion. 4. A flat plate of good conductor is punched out in a slit shape at a predetermined interval from the other end in the direction of one end except for one end, and one end is connected to each other at the one end, and a plurality of slits are arranged in parallel at the slit. A punching step of forming a punched plate having a commutator piece; and a cylindrical body in which the punched plate is bent into a cylindrical shape and the one end portion becomes one end in the axial direction, and the commutator pieces are arranged in the circumferential direction at intervals. And a bending step of forming the cylindrical body into a molding die to mold a resin, and molding a cylindrical insulating resin portion in which the commutator pieces are circumferentially arranged and fixed on the outer peripheral surface at intervals. A method of manufacturing a commutator for a rotary electric machine, comprising: a step; and a separation step of separating the commutator pieces by removing the one end portion. 5. The molding die has a recess for accommodating each of the commutator pieces on an inner peripheral surface forming a cylindrical cavity, and a concave portion for accommodating two adjacent commutator pieces is convex in a central direction. The method for manufacturing a commutator for a rotating electric machine according to claim 4, wherein 6. The rotation according to claim 4, wherein the commutator piece includes a commutator piece body, a hook portion, and an inner claw, and the hook portion is bent in a centrifugal direction and the inner claw is bent in a center direction in the bending step. Manufacturing method of commutator for electric machine.