JP2926460B2 - Method of manufacturing commutator for small motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a commutator for a small motor.

[0002]

2. Description of the Related Art A conventional method for manufacturing a commutator for a small motor is as follows. (A) A method in which a plurality of commutator pieces are created, and the commutator base is manually covered in a cylindrical shape, and then a ring is fitted and fixed.

(B) A plurality of commutator pieces are created,
A method in which these are set on a jig by hand, and then synthetic resin is insert-molded.

(C) A method in which a commutator piece is press-molded into a hat shape from a metal plate material, a synthetic resin is insert-molded, and a plurality of slits are formed in the commutator piece at a plurality of locations.

[0005]

However, in the above method (a), since the commutator pieces are manually covered, the workability of a commutator having a very small diameter is extremely poor.
The productivity was low and the cost was high. In addition, there is a problem in that even if it is fixed with a ring, it is unstable because it is not insert molded.

In the method (b), the commutator pieces are manually set on the jig. Therefore, a commutator having a very small diameter has extremely low workability, low productivity, and high cost. there were.

Further, the method (c) has a problem that it is impossible to manufacture a commutator having an extremely small diameter because slitting is difficult with an commutator having an extremely small diameter.

An object of the present invention is to provide a method for manufacturing a commutator for a small motor that solves these problems.

[0009]

In order to solve the above-mentioned problems, according to the manufacturing method of the present invention, a metal plate (1) is punched out and straight base plates (3a) and (4a) are formed. , (5a)
And a rectangular tip (3b) wider than the base end (4)
b) and (5b), which are radially spaced at equal intervals in the circumferential direction.
A plurality of commu
Thetater pieces (3), (4), and (5) are removed only at the base ends.
So that it remains in a shape connected to the outside of the circle.
(6) and the inside of each base end portion and the outside of the circle.
A plurality of arc-shaped strips extending from the base end to both sides in the circumferential direction
To form the connecting portions (10), (11) and (12)
A plurality of arc-shaped slits (7) outside the circle ;
(8) A punching step of punching and forming (9) , and a tip of each of the plurality of commutator pieces (3), (4) and (5)
(3b), (4b), and (5b) , a processing step of processing into an arc shape, a bending step of bending the leading end of each of the commutator pieces at a right angle, and a predetermined interval between the plurality of bending and raising parts. The plurality of commutator pieces toward the center so as to form a circle of a predetermined diameter across the slit (7),
(8), the connecting portion between the circular hole (9) (1
0), (11), and (12) , while moving while deforming, so that the outer peripheral surface of the upper part of each bent-up portion of the plurality of commutator pieces and the respective base ends are exposed outward. The method further includes a molding step of insert-molding the commutator base (20) , and a cutting step of cutting the respective base ends of the plurality of commutator pieces from the metal plate material.

[0010]

As described above, since a plurality of commutator pieces are insert-molded without being separated from the metal plate material, the commutator pieces are manufactured without manual work, and the manufacture of a commutator having an extremely small diameter is facilitated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a thin band-shaped metal plate material 1 is formed by positioning holes 2 a and 2 b provided on both sides at equal intervals.
While intermittently moving forward in the direction of the arrow, first, as shown in FIG. 2, each commutator is formed in a circular hole 6 so that three commutator pieces 3, 4, and 5 remain, and in a circular arc concentric with the hole 6. Three slits 7, 8, and 9 at positions corresponding to the tether pieces 3, 4, and 5 are sequentially punched by press working.

Each of the commutator pieces 3, 4, 5 has the same shape, and has a linear base end 3a, 4a, 5a extending radially toward the center of the circle from a position separated by 120 ° in the circumferential direction.
And wide rectangular tips 3b, 4b, 5b.

Each of the slits 7, 8, and 9 also extends in an arc shape with a width of 90 ° around a position 120 ° apart in the circumferential direction corresponding to each of the commutator pieces 3, 4, and 5. ing.

Next, the tip portions 3b, 4b of the commutator pieces 3, 4, 5 are intermittently advanced while the metal plate material 1 is intermittently advanced.
As shown in FIGS. 3 and 4, b and 5b are bent into an arc shape at the same circumference.

Next, while the metal plate material 1 is intermittently advanced, the base ends 3a, 4a of the commutator pieces 3, 4, 5 are interposed.
At the boundary between a, 5a and the tips 3b, 4b, 5b, the tips 3b, 4b, 5b are bent upward by a press at right angles, as shown in FIG.

Next, the metal plate 1 is pushed in a horizontal direction toward the center of the circle of the hole 6 with the tip portions 3b, 4b, and 5b bent in an arc shape while intermittently feeding the metal plate 1 intermittently. That is, as shown in FIG. 6, each of the commutator pieces 3, 4 b
While deforming the arc-shaped connecting portions 10 , 11, and 12 between the slits 7, 8, 9 and the circular hole 6 corresponding to 4, 5 respectively, the arc-shaped tips 3b, 4b, 5b are the same. It is moved to a position where a circle having a predetermined diameter is formed across the slits 13, 14, and 15 having a width.

The bending of the tips 3b, 4b, 5b may be performed after the tips 3b, 4b, 5b are moved to the center as shown in FIG.

Next, the metal plate 1 is fed into a molding machine, and as shown in FIGS. 7 to 9, the commutator pieces 3, 4, and 5 are insert-molded on a commutator base 20 by plastic. That is, the commutator base 20 is a cylindrical body having a shaft hole 21, and a small-diameter portion 22 from above.
The middle diameter part 23 and the large diameter part 24 are constituted, and the upper part of the arc-shaped tip parts 3b, 4b, 5b of the commutator pieces 3, 4, 5 is commutator about 1/2 in the thickness direction. It becomes a state buried in the small diameter portion 22 of the base 20, and
b, 4b, 5b and a part of the base end portions 3a, 4a, 5a are buried in the middle diameter portion 23, and the front end portions of the base end portions 3a, 4a, 5a are notches 26 of the large diameter portion 24; Insert molding is performed so as to be exposed on the upper surfaces of 27 and 28.

Next, the base ends 3a, 4a, 5a of the commutator pieces 3, 4, 5 are cut as shown in FIG.
Separate from the metal plate 1. In addition, the base ends 3a, 4a, 5
If the cuts 16, 17, and 18 are processed as shown in FIG. 2A, they can be easily separated.

As described above, a commutator 30 of a small motor is manufactured as shown in FIG. In this manner, since a plurality of commutator pieces are formed on the metal plate material 1 and then insert-molded as they are and then cut off, manual work as in the above-described conventional method is completely unnecessary, workability is significantly improved, and cost reduction is achieved. It becomes possible.

After that, as shown in FIG. 10, one end of the shaft 31 is inserted and fixed in the shaft hole 21 of the commutator base 20, and the large diameter portion 24 of the commutator base 20 is wound with a cylindrical shape. The coreless rotor of the small motor is completed by fixing the winding frame 32 and welding each end of the coil (not shown) to the base end 3a, 4a, 5a of each of the commutator pieces 3, 4, 5. .

In the above process, as shown in FIG. 6, the end portions 3b, 4b of the commutator pieces 3, 4, 5
b, 5b to apply a force to each of the arc-shaped connecting portions 10, 11, 1
After the commutator pieces 3, 4, and 5 have been moved in the direction of the center of the circle by deforming the
0, 11, 12 return to the original state by elasticity, and three tip portions 3b,
The circle by 4b and 5b may be deformed.

FIGS. 11 and 12 show the deformed connecting portions 10 and 1.
An embodiment is shown in which straight ribs 40 are formed by performing a half blanking process or a coining process on 1 and 12. By doing so, the connecting portions 10, 11, 1
Inconvenience due to the return of 2 can be solved.

FIGS. 13 and 14 show another embodiment for solving the inconvenience caused by the return. That is, in the punching step, in addition to the slits 7 ', 8', 9 ', arc-shaped stopper portions 44, 45, 46 are further provided by the slits 41, 42, 43. These slits 41, 42,
The stoppers 44, 45, 46 are slightly bent by punching 43 so as to float from the slits 41, 42, 43. Then, as shown in FIG. 14, after the commutator pieces 3, 4, 5 are moved in the direction of the center of the circle, the stoppers 44, 45, 46 are pushed back flat as before, and the slits 7 ', Fit into 8 ', 9' edge. Therefore, return of the deformed connecting portions 10, 11, 12 is prevented.

FIGS. 15 and 16 show still another embodiment of the present invention. That is, in this embodiment, the slit 7 ',
In addition to 8 ', 9', strips 53, 54, 55 are provided by slits 50, 51, 52 in the direction of extension of the commutator pieces 3, 4, 5 in a straight line. Then, the band plates 53, 54 and 55 are pushed back and the slits 5 are formed.
Return inside the holes defined by 0, 51 and 52.

By doing so, the connecting parts 10, 1
Commutator pieces 3, 4, 5 while deforming 1, 12
When moving in the direction of the center of the circle, the respective band plate portions 53, 54,
55 is accurately guided in the radial direction by the slits 50, 51, 52. Then, after this moving step, both sides of each of the strips 53, 54, 55 and the slits 50, 51, 5
Squeezing 5 by pressing over the edge of 2
6, 57, 58, the connecting portions 10, 1
Return of 1 and 12 can be prevented.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0028]

As described above, in the method of manufacturing a commutator for a small motor according to the present invention, a plurality of commutator pieces are formed on a metal plate and insert-molded as they are, and then cut off. This eliminates the need for manual work as in the above method, greatly improving workability.
Cost reduction becomes possible.

[Brief description of the drawings]

FIG. 1 is a plan view showing a manufacturing method of the present invention.

FIG. 2 is a plan view showing a manufacturing method of the present invention.

FIG. 3 is a plan view showing a manufacturing method of the present invention.

FIG. 4 is a sectional view taken along line AA in FIG. 3;

FIG. 5 is a plan view showing the manufacturing method of the present invention.

FIG. 6 is a plan view showing the manufacturing method of the present invention.

FIG. 7 is a plan view showing the manufacturing method of the present invention.

8 is a sectional view taken along line BB in FIG. 7;

FIG. 9 is a perspective view showing a commutator obtained by the manufacturing method of the present invention.

FIG. 10 is a sectional view of a coreless rotor obtained by the production method of the present invention.

FIG. 11 is a plan view showing a second embodiment of the present invention.

12 is a sectional view taken along the line CC in FIG. 11;

FIG. 13 is a plan view showing a third embodiment of the present invention.

14 is a plan view showing the operation of the embodiment in FIG.

FIG. 15 is a plan view showing a fourth embodiment of the present invention.

16 is a plan view showing the operation of the embodiment in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate material 3, 4, 5 Commutator piece 3b, 4b, 5b Tip 6 Hole 7, 8, 9 Slit 10, 11, 12 Connecting part 20 Commutator base

Claims (1)

(57) [Claims] 1. A metal sheet material (1) is punched out to form a straight band plate.
Base end (3a), (4a), (5a) and width wider than the base end
Wide rectangular tips (3b), (4b) and (5b)
And each of the tip portions is radially spaced at equal intervals in the circumferential direction.
Multiple commutator pieces shaped towards the center of the circle
(3), (4), and (5), except that each base end is outside the circle.
Circular hole (6) so that it remains in the shape connected to the part
And a circle from each base end outside the circle at each base end.
A plurality of arc-shaped strip-shaped connecting portions (1
0), (11) and (12) outside the circle to form
Punching step of punching a plurality of arc-shaped slits (7), (8), and (9) , and each tip (3b) of the plurality of commutator pieces (3), (4), (5 ) , (4b) and (5b) in a circular arc shape, a bending step of bending the tip end of each of the commutator pieces at a right angle, and the plurality of bending and raising parts being separated by a predetermined distance. the commutator pieces of the plurality of toward the center to form a circle of predetermined diameter, said slit (7), (8), the connecting portion between the circular hole (9) (10), (11), (1
2) a moving step of moving while deforming; and a commutator base (20) such that the outer peripheral surface of the upper part of each bent-up portion of the plurality of commutator pieces and the respective base ends are exposed to the outside. And a cutting step of cutting the base end of each of the plurality of commutator pieces from the metal plate material.