JPS6059826B2 - Manufacturing method for motor coil assembly - Google Patents

Description

[Detailed Description of the Invention] In recent years, small electric motors used in consumer equipment such as audio and VTRs, computer terminals, and industrial machines such as control equipment have electronically controlled speed and position, and have become smaller and have higher performance. are increasing (including linear motors).

These electric motors use multiple coils in the stator or rotor, resulting in a complex structure and increased manufacturing costs. The present invention relates to a method of manufacturing a coil assembly for a motor that has the necessary characteristics and functions and reduces manufacturing costs. Generally, coils for electric motors are made by winding an insulated wire around an iron core and fixing it, or by enclosing or fixing it in plastic.

In the latter case, after the pre-manufactured coil is inserted into the space (hereinafter referred to as the cavity) where the molded product is formed in the mold for enclosing or fixing it and temporarily fixing it, a transfer or injection molding machine is used to mold phenol, polyester, epoxy, etc. A thermosetting resin such as diallyl phthalate resin or a thermoplastic resin such as nylon, polypropylene, polybutyl terephthalate, etc. is injected into the mold cavity and solidified to obtain a molded product in which the coil is encapsulated or fixed.

However, in an electric motor that integrates many coils, the operation time of setting the coils in the mold and fixing the lead wire in a predetermined position occupies a major part of the molded product manufacturing time, and as a result, the actual time of the mold forming machine is reduced. This reduces operating time and reduces productivity.

Therefore, in general, if the operation time other than the time required for curing and cooling of such plastic is long, two or more sets of molding molds with a removable cavity part (hereinafter referred to as "cavity block") are manufactured. Then, heat curing of the plastic (in the case of thermosetting resin) or cooling solidification (
In the case of thermoplastic resins, a method is used to increase the molding yield by setting the resin in a separate cavity block during the processing time.

However, in this method, it is desirable to have a good balance between the setting time of the coil in the cavity block and the heating and cooling times. From this point of view, it is preferable to set it in a large number of cavity blocks in advance, and it is necessary to manufacture a large number of cavity blocks.
Furthermore, when molding is performed using a multi-chip mold to reduce molding processing costs, the number of required gates increases further. However, the investment cost for the cavity block part including the main part of the mold is large, and the cavity block replacement method has a complicated structure, making the mold itself expensive. In the present invention, a molded product (hereinafter referred to as the primary molded product) that enables temporary assembly of the coil is molded with plastic that has higher heat resistance than the molding temperature at which it is fixed, and the coil is set in this primary molded product. After molding (hereinafter referred to as secondary molding) by inserting it into a fixed mold (hereinafter referred to as secondary molding), part or all of the primary molded product is removed to eliminate unnecessary or obstructive parts for coil assembly. Therefore, it concerns the structure and molding method to obtain the desired object.

According to the present invention, the primary molded product can be molded easily and at low cost using normal molding methods (compression, transfer, injection molding, etc.), and the necessary amount is prepared by temporarily assembling coils in the primary molding in advance. If secondary molding is performed in advance, the coil setting time required for secondary molding can be greatly shortened, and it is also possible to use a multi-cavity mold for secondary molding, resulting in cost reduction.

In addition, by providing a lead wire processing section in the primary molded product, the operation time for secondary saw layer molding can be shortened, and the primary molded product can be used as a tray for transporting the coil, making it easier to handle. It can be rationalized. To explain in detail with reference to the drawings below, Fig. 1 shows a single coil 1 having a lead wire 4 enclosed or fixed, and Figs. 1 is a coil assembly 3 made of a plastic molded product 2 in which only the outside of the coil is fixed with exposed plastic.

The plastic molded product 2 can simultaneously form functional parts related to other parts other than fixing the coil 1, and can also be molded by connecting the saw lead wire at the end of the coil 1 with other related parts. It is also possible to stand. As shown in FIG. 5, the primary molded product 7 for coil temporary assembly has a columnar or cylindrical shape such as a circle, an ellipse, or a square shape, which has a cutting part 6 that is easy to cut after a notch shape or the like that is pre-molded with plastic. Temporarily assemble the coil 1 to the coil fixing protrusion that is , insert the primary molded product 7 with the coil temporarily assembled into a mold for molding the final product (not shown), and perform secondary molding. The coil is completely fixed with plastic, and the secondary plastic molded part 11 is molded.

Next, as shown in FIG. 6, the coil fixing protrusion 8 is pressed through the notch-shaped cutting part 6 provided on the primary molded product 7 to remove the primary molded product removal part 9, and the primary molded product is removed. A coil assembly 3 as shown in FIG. 7 is manufactured, which is made up of the remaining part 10, the secondary molded part 11, and the coil 1.Also, the primary molded product 7 may be completely removed after the secondary molding. .Furthermore, the lead wire 4 is fixed to a part of the primary molded product, or
Alternatively, the primary molded product and the related components may be connected to related parts and simultaneously inserted into a secondary molding die and molded. The coil assembly thus obtained has the coil fixed only on the outside, with the inside and upper and lower surfaces of the coil exposed, and is used for highly durable, high-performance electric motors.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a single coil, Figs. 2 to 4 are perspective views showing an example of a coil assembly for an electric motor, and Fig. 5 is a perspective view of a primary molded product for temporary coil assembly used in the present invention. 6 is a cross-sectional view of a composite molded product of a primary molded product and a secondary molded part for explaining the method of the present invention, and FIG. 7 is a cross-sectional view of one embodiment of a coil assembly obtained by the present invention. .

Claims (1)

[Claims] 1. When manufacturing a coil assembly for an electric motor that uses multiple coils to electronically control rotational speed, the coils are temporarily assembled into a pre-manufactured plastic molded product and inserted into a mold for fixing the coil while temporarily assembled. 1. A method of manufacturing a coil assembly for an electric motor, which comprises removing part or all of a molded product in which the coil is temporarily assembled after fixing the coil with plastic.