JP3212142B2 - Commutator and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commutator used for a commutator motor such as a power tool and a method for manufacturing the same.

[0002]

FIG. 13 shows the structure of a conventional general commutator. In the conventional commutator, as shown in the drawing, a plurality of segments 1 having the same shape and the same number as the plurality of segments 1 having a wedge-shaped cross section are alternately arranged, and are tightened from the outer circumferential direction. A commutator cylinder is formed, and the commutator cylinder is connected to the V-shaped mica insulating ring 2 from both ends.
, And is firmly fixed by the commutator spider 3 and the commutator tightening ring 4 so that the segment 1 jumps out of the centrifugal force at the time of high-speed rotation or the hiber phenomenon is remarkably suppressed.

[0003]

In the above-described conventional commutator structure, the manufacturing cost of the segment 1 and the mica between the insulating pieces having substantially the same shape as the segment 1 are required, so that the manufacturing cost is high. Further, there is a disadvantage that the commutator manufacturing cost is very high due to the high manufacturing cost of the commutator spider 3 and the commutator tightening ring 4 and the like.

The present invention has been made to solve the above problems, and has as its object to provide a method of manufacturing a commutator capable of producing a commutator that can withstand high temperature and high speed rotation at low cost. .

[0005]

According to a method of manufacturing a commutator according to the present invention, the same number of protrusions as segments are formed on one surface of a strip-shaped conductive plate, and cut-out portions extending in the middle direction from both ends of the protrusions. An annular body is formed with the surface having the cut-out portion as an inner surface, and a high-strength insulator that is substantially annular is disposed on the inner surface of the annular body, and the cut-out portion holds the high-strength insulator. The thus bent product is molded with a mold resin, grooved and separated into segments to form a commutator.

[0006] A method of manufacturing a commutator according to the present invention includes:
The same number of protrusions as the segments are formed on both sides of the strip-shaped conductive plate, and a cutout along the middle direction is provided on the protrusion on the riser side, and a ring with the cutout part on the inner surface is formed. A ring-shaped high-strength insulator is disposed on the inner surface of the annular body, and the cut-out portion and the convex portion on the side opposite to the riser are bent so as to hold the high-strength insulator with a mold resin. It is molded, grooved and separated into segments to make commutators.

[0007]

According to the present invention, the centrifugal force applied to the segment during high-speed rotation is received by the high-strength insulator through the cut-out portion, so that it can withstand a high rotation speed. Further, since the centrifugal force does not depend on the strength of the mold resin, the commutator can withstand a high centrifugal force even when the temperature of the commutator becomes high.

[0008]

[Embodiment 1] 1 and 2 show an embodiment of the present invention.
Will be described. In the figure, reference numeral 5 denotes a segment having a cut-out portion 6. Reference numeral 7 denotes a substantially annular high-strength insulator, 8 denotes a mold resin, and 9 denotes a bush. With such a configuration, the centrifugal force applied to the segment 5 during high-speed rotation is received by the high-strength insulator 7 via the cut-out portion 6, so that it can withstand a high rotation speed. Further, since the centrifugal force does not depend on the mold resin 8, even if the commutator becomes hot, it can withstand a high centrifugal force.

Embodiment 2 FIG. The method of manufacturing the commutator shown in FIGS. 1 and 2 will be described with reference to FIGS. FIG. 3 shows a side view in the longitudinal direction of the strip-shaped conductive plate 11 having the convex portions 10, and the convex portions 10 are formed by processing with a cutter or the like. Next, as shown in FIG. 4, the convex portion 10 is cut out to form a cut-out portion 6. The strip-shaped conductive plate 11 having the cut-out portion 6 is rolled into a ring to form a ring-shaped body 12. FIG. 5 shows an assembly diagram of the annular body. The high-strength insulator 7 is made of a high-strength engineer plastic or a metal-ring-reinforced reinforcing ring such as a metal ring molded with plastic or ceramic.
In the case of ceramic, the cutter escape groove 13 at the time of grooving is used.
It is better to provide This high-strength insulator 7 includes an annular body 1
2 is swaged by the shaving portion 6 so as to be held from both sides. This state is shown in FIG. Thereafter, after the structure and the insert shown in FIG. 5 are molded at the same time, grooving and the like are performed to complete the commutator shown in FIGS.

Embodiment 3 FIG. FIG. 7 shows another embodiment of the present invention.
FIG. 8 will be described. In the drawing, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the figure, reference numerals 14 and 15 denote protrusions provided symmetrically on both sides of the segment 5, and the protrusion 14 on the riser side is separated into a riser portion 16 and a cut-out portion 17.

Embodiment 4 FIG. A method of manufacturing the commutator shown in FIGS. 7 and 8 will be described with reference to FIGS. FIG. 9 shows a strip-shaped conductive plate 11 in which the same number of protrusions 14 and 15 as the segments 5 are provided symmetrically on both sides. FIG. 10 is a side view of FIG. 9 viewed from the width direction, and shows a view in which a cutout portion 17 is provided on the convex portion 14 on the riser side. The belt-shaped conductive plate 11 thus produced is rolled into a ring to form a ring 18. FIG. 11 is an assembling drawing. The strip-shaped conductive plate 11 of FIG.
This state is shown in FIG. Thereafter, the structure shown in FIG. 11 is molded and subjected to grooving, etc.
The finished commutator shown in Fig. Is made.

[0012]

As described above, according to the present invention, the segments are mechanically held at the time of high rotation in order to strongly adhere the segments to the substantially annular high-strength insulator. And the centrifugal force does not depend on the strength of the molding resin. Therefore, even if the commutator becomes hot, it can withstand high centrifugal force. Since a conductive plate is used, an effect is obtained that it is cheaper and can be mass-produced than a commutator of the segment arrangement type.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a commutator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a longitudinal side view of a strip-shaped conductive plate showing a manufacturing process of the commutator of Example 1.

FIG. 4 is a side view in the width direction of the strip-shaped conductive plate when FIG. 3 is viewed from the right.

FIG. 5 is a view in which the strip-shaped conductive plate of FIG. 3 is assembled into an annular body.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5;

FIG. 7 is a side sectional view of a commutator according to a third embodiment of the present invention.

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

FIG. 9 is a front view in the longitudinal direction of a strip-shaped conductive plate showing a manufacturing process of the commutator of Example 3.

FIG. 10 is a side view in the width direction of the belt-shaped conductive plate when FIG. 9 is viewed from the right.

11 is a view in which the belt-shaped conductive plate of FIG. 9 is assembled into an annular body.

FIG. 12 is a sectional view taken along line XII-XII in FIG. 11;

FIG. 13 is a side sectional view showing a conventional general commutator.

[Explanation of symbols]

 Reference Signs List 5 segment 6 cut-out portion 7 high-strength insulator 8 mold resin 9 bush 10 convex portion 11 belt-shaped conductive plate 12 annular body 14 convex portion 15 convex portion 16 riser portion 17 cut-out portion 18 annular body

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01R 39/04 H01R 43/08 H02K 13/00

Claims (4)

(57) [Claims] 1. A convex portion having the same number as the number of segments is formed on one surface of a strip-shaped conductive plate, and a cut-out portion is provided from both ends of the convex portion in a middle direction. After the body is formed, a substantially annular high-strength insulator is provided on the inner surface of the annular body, and the cut-out portion is bent so as to hold the high-strength insulator, and then subjected to grooving. Commutator separated into segments. 2. A projecting portion having the same number as the segments is formed on one surface of the strip-shaped conductive plate, and cut-out portions are provided along both ends of the projecting portions in the middle direction. A body is provided, a substantially annular high-strength insulator is provided on the inner surface of the annular body, and the cut-out portion is molded so as to hold the high-strength insulator and molded and grooved. A method for manufacturing a commutator, wherein the commutator is separated into segments. 3. The same number of projections as the segments are formed on both sides of the belt-shaped conductive plate, and a cutout portion is provided along the middle direction on the protrusion on the riser side. After forming an annular body, a high-strength insulator having a substantially annular shape was disposed on the inner surface of the annular body, and the high-strength insulator was bent so as to hold the high-strength insulator by the cut-out portion and the convex portion on the side opposite to the riser. A commutator that is formed by molding and then grooving it into segments. 4. The same number of projections as the number of segments are formed on both sides of the strip-shaped conductive plate, and a cut-out portion is provided along the middle direction in the protrusion on the riser side, and the surface having the cut-out portion is formed on the inner surface. An annular body is formed, and a substantially annular high-strength insulator is disposed on the inner surface of the annular body, and the high-strength insulator is bent so as to hold the high-strength insulator by the cut-out portion and the convex portion on the side opposite to the riser. A method of manufacturing a commutator, comprising: forming a mold, dividing the mold into segments, and forming a groove.