JPH08273964A - Method for manufacturing coil winding core of step motor for electronic clock - Google Patents

Abstract

PURPOSE: To reduce amount of unneeded material to be scrapped by crushing, in thickness direction, both edge parts and center part of a coil winding core base material with a larger sectional area than that of a winding core part and machining an unneeded part which is crushed and pressed out to form the winding core part and a lug part in a specific shape. CONSTITUTION: A coil winding core base material 2 with a specific length is cut from a loop-shaped rod-shaped material 1 by press machining. The sectional area of the rod-shaped material 1 in this case is made larger than that of a winding core part 4 of a coil winding core 3 to be completed. Also, the sectional shape of the rod-shaped material 1 should be circular. Then, both edge parts of the cut coil winding core base material 2 are bent and both the bent edge parts and a center part are pressed by press machining, thus forming lug parts 5, 5 and the winding core part 4 with a specific thickness. Then, an unneeded part which is pressed out being produced in the formation process of the lug parts 5, 5 and the winding core part 4 is machined to a specific shape as the coil winding core 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a step mode for an electronic timepiece.
The present invention relates to a method for manufacturing a coil core of a coil.

[0002]

2. Description of the Related Art While step motors are required to have high performance such as low current consumption and high output torque, they are strongly required to be manufactured at low cost. Among them, the coil is expensive because it is composed of the coil winding core, the magnet wire wound around the coil core, the terminal sheet connected to the output terminal of the circuit, and the winding frame, and is particularly inexpensive to manufacture. Is requested.

A conventional general coil core manufacturing method is as follows.
It was manufactured by stamping from a strip of material. However, with such a manufacturing method, many wasteful materials are discarded, and it has been difficult to manufacture at low cost.

In order to eliminate the above-mentioned drawbacks, Japanese Patent Publication No. 6-
As disclosed in Japanese Unexamined Patent Publication No. 106016, there has been proposed a method of manufacturing a coil core from a bar made of a magnetic material.
In this Japanese Patent Publication No. 6-160016, in order to increase the area of the ear portion connected to the stator, both ends of the bar are crushed in advance toward the center in the longitudinal direction to increase the diameter. After that, the both ends are crushed in the thickness direction.

[0005]

However, according to this manufacturing method, it is difficult to form a die for crushing the rod material from two directions, which are orthogonal to each other in the longitudinal direction and the thickness direction, and the number of steps is increased, so that the bar can be manufactured at low cost. Has no drawbacks.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and obtain an inexpensive coil winding core.

[0007]

The gist of the present invention for achieving the above object is to provide both end portions of a coil core preform having a cross-sectional area larger than a cross-sectional area of a winding core portion around which a magnet wire is wound. And the central portion is crushed in the thickness direction, and the unnecessary portion that is crushed and then squeezed out is processed to form a winding core portion and an ear portion having a predetermined shape.

[0008]

The present invention will be described in detail with reference to the drawings.
FIG. 1 shows a method of manufacturing a coil core according to the present invention.
(A) shows a step of cutting a coil core base material 2 of a predetermined length from a loop-shaped rod-shaped material 1 by pressing. The cross-sectional area of the rod-shaped material 1 is larger than the cross-sectional area of the winding core portion 4 of the completed coil winding core 3 described later. The cross-sectional shape of the rod-shaped material 1 is preferably circular. FIG. 1 (b) shows a step of bending both ends of the cut coil core base material 2, and FIG. 1 (c) presses the bent both ends and the central portion by pressing to form an ear portion having a predetermined thickness. 5 (a) and 5 (b) and the winding core portion 4 are formed, and FIG. 1 (d) shows a portion of the ears 5, 5 and winding portion 4 which is not required to be protruded and formed into a predetermined shape. Then, a process of completing the coil winding core 3 will be described. 1 (e) is an enlarged cross-sectional view of the winding core portion 4 of FIG. 1 (c). The coil core 3 manufactured by the above manufacturing method can increase the area of the ears 5, 5, so that the driving efficiency of the step motor is not reduced.

FIG. 2 is a front view of the coil winding core 3. The center positions of the ears 5 and 5 can be set freely, as shown in FIG.
As shown in FIG.
As shown in FIG. 2B, it coincides with the center position of the winding core 4, and FIG.
As shown in (c), it may be provided below the center position of the winding core 4.

FIG. 3 is a sectional view of the winding core portion 4 of the coil winding core 3. It is preferable that the crushed portion of the winding core portion 4 has an arcuate shape as shown in FIG. In FIG. 3 (a), the side surface is formed into a linear shape in order to process the unnecessary portion into a predetermined shape. However, as shown in FIG. 3 (b), the straight portion is shortened or post-processing such as a barrel is performed. If the elliptical shape or a shape similar thereto is used, the subsequent formation of the insulating layer can be performed at a low cost as described later.

FIG. 4 shows a coil core manufactured according to still another embodiment of the present invention, FIG. 4 (a) is a plan view,
FIG.4 (b) shows a front view. In order to increase the magnetic coupling area between the winding core 4 and the ears 5 and 5, the ears 5 and 5 have thick portions 5a and 5a.
Are formed. This shape has the effect that the driving efficiency of the step motor is not reduced even if the ears 5, 5 are thin.

In the coil core 3 thus manufactured, an insulating tape, an oxide film, an electrostatic coating, or other insulating layer is formed on the core 4 after that, and the magnet wire is collapsed if necessary. A reel is attached for prevention. The oxide film is the cheapest as the insulating layer, but since this oxide film is formed by oxidizing the surface of the winding core 4 by about 1 μm, if the winding core 4 has corners, the insulating coating of the magnet wire will be formed. Easy to hurt. As shown in FIG. 3 (b), when the winding core 4 has an elliptical cross section or a similar shape, the insulating coating of the magnet wire is not damaged. Therefore, an oxide coating may be used as the insulating layer. I can.

[0013]

As is apparent from the above description, according to the present invention, since the coil core is manufactured from the rod-shaped material, the amount of wasteful material to be discarded is extremely small. Also, since a thick rod-shaped material is used, the crushing direction is only one direction, and it is not necessary to form a complicated mold structure. Therefore, the coil core can be manufactured at a very low cost, and the effect is great.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing an embodiment of the present invention.

FIG. 2 is a front view of a coil core manufactured according to an embodiment of the present invention.

FIG. 3 is a sectional view of a winding core portion according to the present invention.

FIG. 4 is a plan view and a front view of a coil core manufactured according to another embodiment of the present invention.

[Explanation of symbols]

 1 Rod-shaped material 2 Coil core base material 3 Coil core 4 Core part 5 Ear part 5a Thick part provided in the ear part

Claims (3)

[Claims] 1. A method for manufacturing a coil core, comprising crushing both ends of a coil core base material made of a magnetic material to form ears to be coupled with a stator, wherein a magnet wire is wound. Crush the central portion and both end portions of the coil core base material having a cross-sectional area larger than the cross-sectional area of the winding core,
A method of manufacturing a coil core of a step motor for an electronic timepiece, characterized in that an unnecessary portion that is crushed and then protruded is processed to form a core portion and an ear portion having a predetermined shape. 2. The method for manufacturing a coil core of a step motor for an electronic timepiece according to claim 1, wherein the crushed portion of the core portion has an arc-shaped cross section. 3. The method for manufacturing a coil core of a step motor for an electronic timepiece according to claim 1, wherein a thick portion is provided at a connecting portion of the ear portion with the winding core portion.