JPH0819225A - Rotating electric machine commutator and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a commutator for a rotating electric machine and a method for manufacturing the same, which can reduce the depth of an undercut groove while suppressing the extension of the manufacturing process and the occurrence of burrs. According to the first aspect of the present invention, before the insulating resin portion 1 is formed, a bent portion extending in the axial direction is formed in the undercut groove formation planned region of the cylindrical body. After that, after forming the insulating resin portion 1, the outer peripheral surface of the cylindrical body is processed into a cylindrical surface. As a result, the outer peripheral surface of the bent portion is shaved and thinned, and the bent portion as a whole has a concave portion formed on the inner peripheral side thereof. The depth of the undercut groove 3 can be reduced. In the second invention, since the linear concave groove is formed in the undercut groove formation-scheduled region of the plate material, both ends of the plate material are abutted so that the linear concave groove is on the inner peripheral side to form the cylindrical body. The linear groove can be formed in the process, and the undercut groove 3 can be shallowed by the depth of the linear groove without causing burrs.

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 FIG. 7 shows a commutator of a conventional rotating electric machine.
To make this commutator, press the copper plate into the shape required for wire connection and connection with the mold resin, and then
The insulating resin portion 100 is formed by rounding into a cylindrical shape by molding, and thereafter, the outer peripheral side main surface of the copper cylinder is processed into a complete cylindrical surface, and the undercut groove 300 is recessed, and each commutator is formed from the copper cylinder. The piece 200 is divided.

FIG. 8 shows another conventional commutator. In order to manufacture this commutator, a linear concave groove 400 is broached from the inner peripheral surface side in a copper cylinder undercut groove planned region,
After that, the resin mold and the undercut groove 300 are sequentially provided.

[0004]

In the former publication, the undercut groove 300 needs to be deeper than the thickness of the copper plate to completely separate the commutator pieces 200 from each other. There was a problem that the mechanical strength of the insulating resin part 100 that holds 200 against frictional heat and centrifugal force is lowered, and the thermal deformability is increased.

In the latter publication, although the depth of the undercut groove 300 can be reduced by the depth of the linear concave groove 400 broached on the inner peripheral surface of the copper cylinder, the above problems can be reduced, but the copper Since the linear groove 400 must be broached on the inner peripheral surface of the cylinder, the process becomes complicated, and the commutator pieces 20 adjacent to each other due to the burrs generated by the broaching process.
There is a new defect that 0 easily becomes a rare earth.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a commutator for a rotary electric machine that can reduce the depth of the undercut groove while suppressing the extension of the manufacturing process and the occurrence of burrs. Its purpose is.

[0007]

A first structure of a method for manufacturing a commutator for a rotating electric machine according to the first aspect of the present invention comprises a step of forming a tubular body having a predetermined number of bent portions in the axial direction, and then the tubular body. A step of injecting a resin into the body to form a tubular insulating resin portion, and then processing the outer peripheral surface of the tubular body into a cylindrical surface, and the bent portion of the tubular body to the insulating resin portion And a step of forming a plurality of commutator pieces that are cut and spatially separated from each other.

According to a second structure of the first invention, in the first structure, further, after bending the plate material to form a predetermined number of bent portions in the axial direction, both end faces of the plate material are abutted to form a tubular body. It is characterized by forming. A third configuration of the first invention is characterized in that, in the first configuration, the bent portion is formed by a number smaller than the number of the commutator pieces by one.

The first structure of the method for manufacturing a commutator for a rotary electric machine according to the second aspect of the present invention comprises the steps of forming linear concave grooves in parallel with each other on a main surface of a plate material at regular intervals. A step of forming a cylindrical body by abutting both end surfaces of the plate material so that the groove is on the inner peripheral side; and a step of injecting a resin into the cylindrical body to form a cylindrical insulating resin portion. Next, the outer peripheral surface of the cylindrical body is processed into a cylindrical surface, and the linear groove portions of the cylindrical body are undercut to the insulating resin portion to form a plurality of commutator pieces spatially separated from each other. And a process.

A second structure of the second invention is further characterized in that, in the first structure, the linear groove is formed by a step of punching the plate material from a strip plate. A commutator for a rotating electric machine according to a third aspect of the present invention includes a cylindrical insulating resin portion,
A commutator for a rotating electric machine comprising a plurality of commutator pieces arranged at a constant angle in a circumferential direction on an outer peripheral surface of the insulating resin portion, and an undercut groove recessed between adjacent commutator pieces. In the above, each of the commutator pieces is characterized by including an inner peripheral side main surface having a polygonal plane cross section and a cylindrical outer peripheral side main surface.

[0011]

According to the present invention, the bent portion extending in the axial direction is formed in the region where the undercut groove is to be formed in the cylindrical body before the insulating resin portion is formed. After this, after forming the insulating resin portion, the outer peripheral surface of the cylindrical body is processed into a cylindrical surface. At this time, the surface on the outer peripheral side of the bent portion is shaved and thinned,
The bent portion as a whole has a concave portion formed on the inner peripheral side thereof. Therefore, after filling the cylinder with resin,
The undercut depth at the time of undercutting the bent portion can be reduced by the thinned portion of the bent portion, and the dug amount of the insulating resin portion can be reduced accordingly. By doing so, the conventional method of forming a cylinder by rolling a plate material is changed to form a cylinder having a plurality of bent portions, and the mechanical strength and thermal deformation of a conventional commutator are reduced. It is possible to solve problems such as increase in sex. Also, the undercut process becomes easy.

According to a second structure of the first invention, in the above-described first structure, a plate member punched into a predetermined shape is further bent to form a predetermined number of bent portions in the axial direction, and then a tubular body is formed. Therefore, there is a great advantage that it is extremely easy to form the bent portion. For example, when punching a plate material having a predetermined shape from a strip plate, a linear groove is formed in this bent portion.
With this configuration, when the plate member is bent to form the cylindrical body, the plate member bends naturally or easily at the thin-walled bent portion. of course,
It is of course possible to form the bent portion by another method, and such bending of the plate material or the band plate is within the range of well-known techniques, and at this time, burrs do not occur.

A third structure of the first invention is that, in the first structure, the number of bent portions is smaller by one than the number of commutator pieces. In this case, the minimum number of bent portions is required, so that the bending angle can be set large and the undercut depth of the bent portions can be reduced. The first configuration of the method for manufacturing a commutator for a rotating electric machine according to the second aspect of the invention is to form a linear concave groove in a region to be formed with an undercut groove of the plate material, and then to form the linear concave groove on the inner peripheral side. Since the cylindrical body is formed by abutting both end faces, the linear groove can be formed in a simple process, and the undercut groove can be shallowed by the depth of the linear groove without causing burrs. Therefore, the strength of the insulating resin portion and the heat distortion resistance can be improved. Further, since the tubular body easily bends at the linear groove portion, the bent portion is thinned during the subsequent polishing (grinding) of the outer peripheral surface of the tubular body, and the bending portion is thinned accordingly. , The amount of undercut can be reduced,
The same effect as that of the first aspect of the invention can be obtained at the same time.

In the second structure of the second invention, since the linear concave groove is formed by the step of punching the plate material from the strip plate in the first structure, the linear groove can be formed without increasing the number of steps. It is possible to obtain an extremely excellent effect that the concave groove can be formed. Each commutator piece of the commutator of the rotating electric machine according to the third aspect of the invention includes an inner peripheral main surface having a polygonal shape and a polygonal overall cross section in the axial direction, and a cylindrical outer peripheral main surface. That is, it has a shape produced by the first configuration of the first invention. By doing so, the depth of the undercut groove can be reduced, so that the same effect as the first invention can be obtained.

[0015]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional front view of the commutator of a vehicle starter motor as viewed from the radial direction, and FIG. 2 is a front view of a semi-finished product thereof.

As shown in FIG. 1, this commutator has an insulating resin portion 1 having a tubular shape with a dodecagonal cross section, and is arranged on the outer peripheral surface of the insulating resin portion 1 every 30 degrees in the circumferential direction. An undercut groove 3 is formed between the adjacent commutator pieces 2 and is formed between the adjacent commutator pieces 2 by slightly biting into the outer peripheral surface of the insulating resin portion 1. Reference numeral 46 denotes an outer claw (locking piece portion) formed radially outward from the axial inner end of each commutator piece, and the end of an armature conductor (not shown) is locked.

The feature of this embodiment is that the outer peripheral side main surface of the commutator piece 2 is a partially cylindrical surface and the inner peripheral side main surface is a flat surface, so that each commutator piece 2 is The main surface on the outer peripheral side is a cylindrical surface as a whole except for the portion of the undercut groove 3, and the main surface on the inner peripheral side of each commutator piece 2 is a regular dodecagonal shape except for the portion of the undercut groove 3. It is on the cylindrical surface.

By doing so, the undercut depth at the time of forming the undercut groove 3 can be reduced, so that the strength of the insulating resin portion 1 and the thermal deformation resistance can be improved as described above. Hereinafter, a method for manufacturing the commutator will be described with reference to FIGS. First, as shown in FIG. 4 (a), a strip-shaped copper plate 4 is punched into a predetermined shape to form a plate material 4, and a line-shaped copper plate 4 shown in FIG. The grooves 5 and 51 are formed.

The linear groove 5 is formed in the axial direction (parallel to the axis of the cylinder), and the width between the adjacent linear grooves 5 is constant. In addition, in the example of FIG. 5A, the linear groove is formed from both sides to form the residual plate portions 40 and 41 at the central portion in the thickness direction of the plate member 4, but in FIG. In the example c), the linear grooves 5 and 51 are formed on the one main surface side, and the residual plate portions 40 and 41 are formed on the other surface side. Either linear groove structure may be adopted. In addition, 51 in FIG. 5A is a half-line-shaped groove formed on both end faces of the punched plate member 4, and 41 is a semi-remaining plate portion, at a stage where both end faces of the plate member 4 are butted. The two half-line concave grooves 51 form one linear groove 5, and at that time, the two half-remaining plate portions 41 form one remaining plate portion 40. Further, FIGS. 5B and 5C show both end faces of one plate member 4, and the thin residual plate portion 40 is the plate member 4.
Is formed only at one end. c is a butt end surface. Of course, it is also possible to divide the residual plate portion 40 into halves as shown in FIG.

Reference numeral 51 is a half-line concave groove formed on both end faces of the punched plate member 4, 41 is a semi-remaining plate portion, and both half-line concave grooves are formed at the stage where both end faces of the plate member 4 are butted. 51 forms one linear groove 5, and at this time, the two half-remaining plate portions 41 form one half-remaining plate portion 40. Next, as shown in (b) of FIG. 4, the inner claw 43 is cut and raised from the hooking formation scheduled piece 42 at 90 degrees.

Next, as shown in FIG. 4C, the plate member 4
Is rounded, but at this time, the plate member 4 is bent at the portion of the linear concave groove 5 so that the linear concave groove 5 is on the inside to form a regular dodecagonal cylinder body 45. Next, as shown in FIG. 5A, the inner claw 43 is bent inside the cylindrical body 45, and then, as shown in FIG. The claw 44 is bent inside the cylindrical body 45.

Next, as shown in FIG. 5C, a resin is molded inside the cylindrical body 45, and then the cylindrical body 4 is formed.
The outer peripheral surface of 5 is ground into a complete cylindrical surface, and the outer claw (locking piece) 46 for locking the armature conductor, which is composed of the remaining piece 42 for forming the locking portion, is bent outward to form the cylindrical body 45. Complete. Next, the undercut groove 3 is dug in the portion of the linear concave groove 5 of the cylindrical body 45, that is, the bent portion, and the plate member 4 is divided into the commutator pieces 2 to complete the commutator.

As described above, in the commutator of this embodiment, since the depth of the undercut groove 3 can be set to a required depth smaller than the thickness of the original plate material 4, centrifugal strength can be achieved without broaching. Also, the heat distortion resistance can be improved. FIG. 2 shows an axial front view of the tubular body 45 before the undercut groove 3 is recessed, and FIG. 3 shows a state in which this commutator is mounted on a starter motor.

(Modification 1) In the above embodiment, the linear groove 5 is formed to form the bent portion. However, without forming the linear groove 5, the bent portion is formed before the formation of the cylindrical body 45. Can be provided in a region where the undercut groove 3 is to be formed. (Modification 2) In the above embodiment, the outer peripheral surface of the cylindrical body 45 bent into a regular polygon is ground to form a cylindrical surface. However, since the linear concave groove 5 is formed in the region where the undercut groove 3 is to be formed. Since the depth of the undercut groove 3 can be reduced by the amount of the linear concave groove 5, the cylindrical body 45 may be cylindrical. However, cylinder 4
By bending 5 into a regular polygon and providing the linear concave groove 5, the depth of the undercut groove 3 can be further reduced, and it is easy to bend into a regular polygon.

(Modification 3) In the above embodiment, the step of bending into a regular polygon can be performed after the tubular body 45 is formed. In the above embodiment, the outer peripheral surface of the tubular body 45 was processed into a complete cylindrical surface, and then the bent portion of the tubular body 45 was undercut to the insulating resin portion. However, contrary to the above, the bent portion of the tubular body 45 is After undercutting up to the insulating resin portion, the outer peripheral surface of the cylindrical body 45 may be processed into a complete cylindrical surface, contrary to the above.

[Brief description of drawings]

FIG. 1 is a cross-sectional front view of a commutator of a vehicle starter motor as viewed in a radial direction.

FIG. 2 is a front view of the semi-finished product of the commutator of FIG. 1, and more specifically, is an axial front view of a tubular body 45 before recessing the undercut groove 3.

FIG. 3 is a side view showing a state in which the commutator of FIG. 1 is attached to a starter motor.

FIG. 4 is a process drawing showing a commutator manufacturing process.

FIG. 5 is a process drawing showing a commutator manufacturing process.

6A and 6B are cross-sectional views of the plate member 4, where FIG. 6A shows the cross-sectional shape of the plate member 4 of the present embodiment, and FIGS. 6B and 6C show another embodiment of the plate member 4.

FIG. 7 (a) is a radial cross-sectional view of a conventional commutator,
(B) is the elements on larger scale.

FIG. 8A is a radial cross-sectional view of a conventional commutator,
(B) is the elements on larger scale.

[Explanation of symbols]

1 is an insulating resin part, 2 is a commutator piece, 3 is an undercut groove,
4 is a plate material and 5 is a linear groove.

Claims (6)

[Claims] 1. A step of forming a tubular body having a predetermined number of bent portions in the axial direction, a step of injecting a resin into the tubular body to form a tubular insulating resin portion, Processing the outer peripheral surface of the tubular body into a cylindrical surface, and undercutting the bent portion of the tubular body to the insulating resin portion to form a plurality of commutator pieces spatially separated from each other. A method for manufacturing a commutator of a rotating electric machine, which is characterized. 2. The method of manufacturing a commutator for a rotary electric machine according to claim 1, wherein after bending the plate material to form a predetermined number of bent portions in the axial direction, both end faces of the plate material are butted against each other to form a cylinder. 3. The bent portion is 1 from the number of the commutator pieces.
The method for manufacturing a commutator for a rotary electric machine according to claim 1, wherein only a small number is formed. 4. A step of forming linear recessed grooves on one main surface of the plate member in parallel with each other at regular intervals, and then, on both end faces of the plate member so that the linear recessed grooves are on the inner peripheral side. A step of forming a cylindrical body by butting, a step of injecting resin into the cylindrical body to form a cylindrical insulating resin portion, and then processing the outer peripheral surface of the cylindrical body into a cylindrical surface, A step of undercutting the linear groove portion of the cylindrical body to the insulating resin portion to form a plurality of commutator pieces that are spatially separated from each other, and manufacturing a commutator for a rotating electric machine, comprising: Method. 5. The method of manufacturing a commutator for a rotary electric machine according to claim 4, wherein the linear groove is formed by punching the plate material from a strip plate. 6. A cylindrical insulating resin portion, a plurality of commutator pieces arranged on the outer peripheral surface of the insulating resin portion at a constant angle in the circumferential direction, and a recess provided between each adjacent commutator piece. In a commutator of a rotating electric machine having an undercut groove formed therein, each commutator piece has an inner peripheral main surface having a polygonal axial cross section and a cylindrical outer peripheral main surface. A commutator for a rotating electric machine, comprising: