JPS61258650A - Manufacture of rotor for flat motor - Google Patents

Abstract

PURPOSE:To improve resin injecting velocity at rotor molding time by forming a projection at a position corresponding to the effective length portion of the rotor of an injection mold, and charging resin by the projection in the state of supporting an armature coil. CONSTITUTION:The effective part of an armature single coil 8 disposed at the uppermost part is retained by the projection (a) of an upper mold 21, the effective part of the coil 8 disposed at the third part from above and the entire coil 8 disposed at the lowermost part are retained by the projection (b) of the lower mold 22, and the coil 8 superposed in a laminated state is molded by charging resin in a cavity formed in the molds. Thus, since the resin charged at the rotor molding time is smoothly spread to the coils, the rotor of good balance can be manufactured in a short time.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing a rotor for a flat motor, and in particular, when coating an armature coil with a resin, the armature coil is coated uniformly with the resin, and rotation is improved. This makes it possible to manufacture a rotor that is well-balanced and has good cooling efficiency.

(Prior Art) As shown in FIG. 8, a conventional flat motor includes a housing 3 formed by joining a bracket 1 and a bracket 2, and an oil-impregnated bearing 4 or a ball supported by the bracket 1 and the bracket 2, respectively. A rotating shaft 5 is attached via a bearing or the like, and a commutator 6 and an armature 7 having a boss portion 13 are integrally attached to the rotating shaft 5. In the armature 7, a plurality of armature single coils 8 as shown in FIG. It is connected to the commutator 6 and integrally molded with the rotating shaft 5 in resin.

Further, the commutator 6 is provided with a brush 1 to which an elastic force is applied by a coil spring 12 in a direction toward the commutator 6 in order to supply power to the armature single coil 8.
1 is in contact.

In the bracket 2, a number of permanent magnets 10 corresponding to the number of armature single coils 8 are arranged in a radial manner, with north poles and south poles arranged alternately in a radial manner. is formed. As a method for manufacturing such an armature coil of a flat motor integrally with the boss portion 13 and the rotating shaft 5, there is a method disclosed in Japanese Patent Publication No. 57-29936, and this method is shown in Fig. 10. After forming the commutator 6 consisting of the commutator piece 6A and the boss portion 13 made of resin, the commutator 6 is
After fitting the terminal portion e of the single coil 8 to the connecting portion 14 of the commutator piece 6A while arranging a plurality of single coils 8, the connecting portion 14
The single coil 8, which is heated and melted to electrically connect the commutator piece 6A and the single coil 8, is made by winding a coil wire as shown in FIG. Directional part 8b
And, by connecting these, the effective part as an amateur coil (
a radial portion 8a which becomes a torque generating portion),
The overall shape is a planar trapezoid. The coil wire that makes up the single coil 8 is made up of a central conductor, an insulating layer on the outside, and a thermoplastic resin fusion layer on the outermost part, so all the single coils 8 can be connected to a commutator. 6, by heating the entire armature coil 15 constituted by all the single coils 8, all the single coils 8 are integrally bonded by the fusion layer.

The armature coil 15 thus formed is placed in a molding die 20 having mutually provided ring-shaped protrusions as shown in FIG. By injecting resin into the cavity, the armature coil 15 is entirely solidified with resin and the boss portion 13 is formed.

When the rotor thus formed is viewed from the axial direction, a ring-shaped groove 16 is formed as shown in FIG. This groove 16 is formed by a protrusion provided on the molding die 20 for positioning the armature coil 15.

(Problems to be Solved by the Invention) However, in the conventional rotor manufacturing method as described above, coil winding portions are formed in the upper mold 21 and the lower mold of the mold 20 shown in FIG. Since the resin was injected so as to press the entire armature coil 15 by ring-shaped protrusions having approximately the same height, the resin was difficult to flow at the joint portion of the mold 20.

Therefore, when a pin gate is used to inject resin into the cavity corresponding to the boss portion 13, it becomes difficult for the resin to spread to the outer circumferential portion of the armature 7, and the side where the resin is injected into the cavity corresponding to the outer circumferential portion of the armature 7 is difficult to spread. When a film gate is used, resin is difficult to spread to the boss portion 13.

For this reason, it takes time to inject the resin when molding the rotor, and the density of the resin differs in each part of the rotor, making it difficult to efficiently manufacture a rotor with good rotational balance.

The present invention has been made to solve these conventional problems, and aims to improve the injection speed of resin during rotor molding, and to manufacture a well-balanced rotor. .

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for disposing a predetermined number of amateur single coils in a commutator, and temporarily bonding these amateur single coils to each other. After forming, the armature coil, commutator, and shaft are placed in a mold, a boss is formed with resin, and the armature coil is covered, so that the armature coil, commutator, and shaft are integrated. In a method of manufacturing a rotor for a flat motor, the protrusion presses a specific portion of the armature coil at a position corresponding to the effective length of the rotor of a pair of molding molds forming the rotor. A rotor for a flat motor, wherein a resin is injected into the mold while the armature coil is supported by the protrusion, and a recessed portion in which the surface of the armature single coil is exposed is formed in the rotor. This is a manufacturing method.

(Shichike) Examples of the present invention will be described in detail below based on the drawings.

FIG. 1 is a top view of a rotor manufactured by the manufacturing method according to the present invention, viewed from the axial direction. FIG. 2 is a sectional view of a main part of the rotor shown in FIG. 1. FIG. 3 is a diagram showing a molding process for the armature single coil disposed on the rotor shown in FIG. 1.

For example, when the armature single coil 8 disposed on the rotor is developed in a straight line, it becomes as shown in FIG. 3. As shown in the figure, the amateur single coils 8 are stacked in layers with their phases shifted by 1/4 pitch. In order to mold the armature single coil 8 stacked in layers in this way using the molding die 20, the effective portion of the armature single coil 8 placed at the top is held down by the protrusion a of the upper die 21; Also, the protrusion of the lower mold 22 has already reached the third position from the top.
Holding down the effective part of the armature single coil 8 placed at the th position and the entire armature single coil 8 placed at the bottom,
This is done by injecting resin into the cavities formed by these molds.

As shown in FIG. 1, the rotor formed in this manner has a groove A formed by the protrusion a of the upper mold 21 on one side of the torque generating part of the rotor, and a groove A formed by the protrusion a of the upper mold 21 on the opposite side. The groove B formed by the protrusion 22 is connected to the groove A 1.
The phase is shifted by /4 pitch.

A cross-sectional view of the groove is shown in FIG. 2, and the armature single coil 8 is exposed in the groove A formed by the protrusion of the upper mold 21, and in contact with the lower mold 22. Amateur single coil 8 is also exposed.

FIG. 4 shows another embodiment of the present invention, and FIG. 5 shows a sectional view of a main part of the groove shown in FIG. FIG. 6 is an explanatory diagram showing a molding process for the rotor shown in FIG. 4.

As shown in FIG. 6, the upper mold 21 and the lower mold 22 of the molding mold 20 are provided with spiral projections C facing each other from a portion corresponding to the boss portion of the rotor. A rotor having a spiral groove C as shown in FIG. 4 is formed by pressing a specific portion of the rotor. In Figure 5,
A cross-sectional view of the spiral groove C shown in FIG. 4 is shown,
The amateur single coil 8 is exposed in this groove C.

FIG. 7 shows yet another embodiment.

The upper mold 21 and the lower mold 22 of the molding mold 20 are provided with spiral protrusions d corresponding to one pitch of an armature single coil facing each other from a portion corresponding to the boss portion of the rotor. By pressing a specific portion of the armature coil 15, a rotor having a spiral groove is formed.

(Effects of the Invention) As is clear from the above explanation, after a predetermined number of amateur single coils are arranged in a commutator and an amateur coil is formed by temporarily bonding these amateur single coils to each other, the armature coil is A commutator and a shaft are placed in a mold, a boss is formed of resin, and the armature coil is covered to form a rotor in which the armature coil, commutator, and shaft are integrated. In the method for manufacturing a rotor for a flat motor, a projection for pressing a specific portion of the armature coil is provided at a position corresponding to the effective length portion of the rotor of a pair of molding molds forming the rotor, and the projection presses a specific portion of the armature coil. Injecting resin into the mold while supporting the armature coil,
By forming a recess in the rotor that exposes the surface of the armature single coil, the resin injected during rotor molding can smoothly spread to each armature coil, resulting in a well-balanced rotor that is shorter than before. Now it can be manufactured in hours.

[Brief explanation of the drawing]

FIG. 1 is an axial top view of a rotor molded by the manufacturing method according to the present invention, FIG. 2 is a sectional view of the main parts (II and n-II) of the rotor shown in FIG. 1, and FIG. is an explanatory diagram of the manufacturing method according to the present invention, FIG. 4 is a top view in the axial direction of a rotor molded by another manufacturing method according to the present invention, and FIG. 5 is a cross section taken along ■-■ of the rotor shown in FIG. Figures 6 and 7
Figure 8 is an explanatory diagram of another manufacturing method according to the present invention, Figure 8 is a schematic configuration diagram of a conventional flat motor, Figure 9 is an enlarged view of an amateur single coil of a commonly used flat motor, and Figure 10 is an enlarged diagram of an amateur single coil of a commonly used flat motor. FIG. 11 is an explanatory diagram of a conventional method for manufacturing an amateur coil, FIG. 11 is an explanatory diagram of a conventional rotor manufacturing method, and FIG. 12 is an axial top view of the conventional rotor. 1.2...-Bracket, 3...Housing, 4
...Oil-impregnated bearing, 5...Shaft, 6...Commutator, 6A...Commutator piece, 7...Amateur, 8...Amateur single coil, 9...Gap, 10... Permanent magnet, 11...
・Brush, 12... Coil spring, 13...
Boss part, 14. e... Connection portion, 15... Amateur coil, 16, A, B, C,... Groove a, b, c, d,... Protrusion, 20... Molding mold, 21.・・Upper mold, 22・・
・Lower mold, patent applicant Nippon Radiator Co., Ltd. Figure 2 3 3 ■ New button A Figure 5 C ω

Claims (1)

[Claims] A predetermined number of amateur single coils (
8) and temporarily bond these amateur single coils (8) to each other to form an amateur coil (15), and then connect the armature coil (15), commutator (6), and shaft (5). Mold for molding (20)
The armature coil (15) is installed in the rotor, a boss portion (13) is formed of resin, and the armature coil (15) is covered to form a rotor in which the armature coil (15), the commutator (6), and the shaft (5) are integrated. In the method for manufacturing a rotor for a flat motor, the armature coil (15) is placed at a position corresponding to an effective length portion of the rotor in a pair of molding molds (20) forming the rotor. A projection is provided to press the armature coil (15), and resin is injected into the molding die (20) while the armature coil (15) is supported by the projection, and the surface of the armature single coil (8) is injected into the rotor. A method of manufacturing a rotor for a flat motor in which a concave portion is formed to expose the rotor.