JPH0732551B2 - Method of forming rotating armature coil - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a rotating armature coil, and more particularly to a method for obtaining a rotating armature coil suitable for a starter for starting an internal combustion engine.

[Background of the Invention]

Conventionally, a technique for crushing a part of a round wire into a rectangular wire as an armature coil of a rotary electric machine and inserting and arranging the part into a slot of an armature core to make the end part a round wire is disclosed in, for example, JP-A-54-509.
It is known in Japanese Patent Publication No. 04 or Japanese Utility Model Publication No. 56-164653.

It is widely known that the torque characteristic of an electric motor is greatly affected by the shape of the tooth portion of the armature core. In particular, the greater the influence of the width of the root of the tooth, the narrower the width, the more the magnetic resistance increases,
The torque characteristic of the electric motor deteriorates. The output characteristic of the electric motor is easily affected by the conductor cross-sectional area of the armature, and the larger the cross-sectional area, the larger the output of the electric motor.

Considering the above-mentioned well-known technology based on such characteristics, the former one has a smaller cross-sectional area of the root portion of the tooth portion of the armature as the size of the armature becomes smaller, and the magnetic saturation locally occurs at this portion. Occurs, and the required amount of magnetic flux cannot be obtained. Therefore, in order to improve it, the coil is generally flattened to widen the root. However, this involves a problem that a stepped portion is formed between the lower conductor insertion slot and the upper conductor insertion slot, and the coil coating is destroyed when the conductor is inserted, resulting in dielectric breakdown. There is a gap in the coil and the space factor of the coil cannot be increased, which does not contribute to torque improvement.

In the latter case, the parallel slot grooves are formed on the radiation, and the flattened coil is inserted into the slot grooves. To increase the reluctance,
The torque characteristic of the electric motor is degraded.

[Object of the Invention]

An object of the present invention is to provide a method capable of effectively forming a continuous armature coil having the same sectional area and different sectional shapes.

[Outline of Invention]

The present invention provides a coil forming die which is sequentially arranged and has a coil forming groove having a substantially trapezoidal cross section having different depths and widths,
This is achieved by inserting and arranging a round wire in the corrugation, and then pressingly deforming the conductor portion inserted into the armature core to form the armature coil.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a partial sectional view of the armature, in which the laminated armature core 2 and the molded commutator 3 are press-fitted and concentrically arranged on the rotary shaft 1. The armature core 2 extends axially on its circumference, as shown in cross section in FIG.
It also has a plurality of slots 4 arranged on the radiation. The slots 4 are located next to each other on the radiation,
And the tooth portion 5 having a substantially equal width in the radial direction causes V
It is formed in a letter shape. That is, the tooth portion 5 is the root portion 5a.
The width W from the outer edge to the outer peripheral edge 5b is almost the same.

Although not shown, each of the slots 4 is provided with an insulating paper for insulation or electrostatic powder coating in advance, and an enamel-coated armature coil 6 is disposed therethrough. The armature coil 6 is preliminarily shaped into a waveform as shown in FIG. 3 and is sequentially inserted into the slot 4 as shown in FIG.
And the end portions 61a and 64a are fixed to the riser portion 32 of the commutator piece 31 forming the commutator 3.

Here, the conductor portions 61, 62, 63, 64 of the armature coil are the V
Each of them has a substantially trapezoidal shape in accordance with the V-shaped slot shape, their cross-sectional areas are set to be equal, and the end portions 6a and 6b subsequent thereto have a circular cross-section.

According to the above-described embodiment of the present invention, since the widths of the teeth located adjacent to each other in the radial direction of rotation are substantially equal in the radial direction, the magnetic flux passing through the teeth is constant and the magnetic resistance is small, so that the electric motor High torque characteristics can be obtained. Further, since the V-shaped slot is formed by the shape and the coil conductor portion having the same cross-sectional area is formed according to the shape, the magnetic resistance of the armature core and the internal resistance of the armature coil are reduced to reduce the size. Thus, an armature of a rotating electric machine suitable for high output can be obtained.

Furthermore, since the internal resistance of the coil conductors is uniform, pulsation between the conductors due to current can be suppressed, the output can be stabilized and magnetic noise can be reduced.

In addition, there is an advantage in that it is not necessary to consider local insulation deterioration because local heat generation that occurs in a conductor having a small cross-sectional area is eliminated due to variations in cross-sectional area between coil conductors.

Next, to explain the method of forming the conductor portion of the armature coil with reference to FIGS. 3 to 5, the coil forming die 7 made of the die shown in FIG. 4 has its upper surface opened and its depth gradually decreases. , Coil forming grooves 71, 72, 73, 74 with a generally trapezoidal cross section that gradually increase in width
And the conductor portions 61, 62, 63, 64 of the enamel wire 6 formed into the corrugated shape shown in FIG. 3 are arranged therein. afterwards,
As shown in FIG. 5, a pressing die 9 pressed by a cylinder 8 is pressed by the width of the slot groove to form a coil conductor portion having a substantially trapezoidal shape with different cross-sectional areas. . Here, since the enamel wire is extended to the periphery during the pressure molding and the enamel coating is also extended, the enamel wire is set to be deformed within a range where the insulation is not peeled off, so that there is no problem in use. In the case of using a bare wire, there is no problem in practical use if insulation coating is applied after coil molding.

According to the above-mentioned embodiment, coil forming grooves having different depths and widths which are sequentially arranged are formed in a die, and a coil conductor of a round wire is arranged in the groove and cold pressed, and the cross sectional areas are equal to each other. Since continuous armature coils having different cross-sectional shapes can be effectively formed, it is possible to obtain a coil conductor that is excellent in productivity, inexpensive, and highly accurate.

〔The invention's effect〕

According to the present invention, by using the coil forming grooves which are sequentially arranged and have different depths and widths, continuous armature coils having the same cross-sectional area and different cross-sectional shapes can be effectively formed.

[Brief description of drawings]

The drawings show an embodiment of a method for forming a rotor and an armature coil of a rotating electric machine according to the present invention. FIG. 1 is a partial sectional view of an armature core seen from the front, and FIG. FIG. 3 is a partial cross-sectional side view, FIG. 3 is an exploded view of an armature coil strand, FIG. 4 is a perspective view of a coil forming die, and FIG. 2 ... Armature core, 4 ... V-shaped slot, 5 ... Tooth portion, 61-64 ... Armature conductor, 7 ... Coil forming die, 71-
74 …… Coil forming groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-60-152242 (JP, A) JP-B 56-31818 (JP, B2) JP-B 57-31387 (JP, B2)

Claims (1)

[Claims] 1. A method of molding an armature coil, wherein each slot of an armature core is wound in a multi-layered manner so as to overlap with each other, and at least a portion located in the slot is formed in a square shape, and a subsequent end portion is formed in a round shape. A coil forming die which is sequentially arranged and has a coil forming groove having a substantially trapezoidal cross section having different depths and widths, and a round wire is inserted and arranged in a waveform in the forming die,
Thereafter, the coil conductor portions to be inserted into the armature core are pressed and deformed to continuously form corrugated armature coils having different cross-sectional shapes with the respective conductor portions having the same cross-sectional area. Child coil molding method.