JPH0591712A - Manufacture of stator - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a stator which increases generation torque nearly not reducing frequency characteristics of a stepping motor by eliminating requiring a special press mold, a plurality of press molds, etc., and a number of processes. CONSTITUTION:A hole-machining process for providing a hole part 4 at a center site of a plate-shaped member 1, a magnetic pole tooth machining process for providing the hole part 4 at a center and at the same time providing a common part 2a around the hole part 4 radially, thus forming a magnetic pole tooth forming part 2 for magnetic pole tooth, a division-machining process for machining 3 so that the common part 2a can be divided for each magnetic pole tooth forming part 2, and a bending process for dividing a division shape 3 and then performing rising press machining of the magnetic pole tooth forming part 2 after dividing the division shape 3, are provided for manufacturing a stator for a stepping motor with a plurality of magnetic pole teeth by press forming machining of a flat plate-shaped member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator manufacturing method for manufacturing a stator for a stepping motor having a plurality of magnetic pole teeth by press forming a flat plate member.

[0002]

2. Description of the Related Art Among conventional stepping motors, a type in which a stator is manufactured by press forming a flat plate member is known. This stepping motor is shown in Figure 4.
As shown in the exploded view of FIG. 1, a rotor 11 integrally provided with a multi-pole magnetized permanent magnet is rotatably supported by a bearing 12 provided in a main body 12, while the rotor 11 is
A rotating magnetic field generating means for generating a rotating magnetic field is provided around the outer circumference of the permanent magnet, and the rotating magnetic field generating means is energized with a predetermined current to drive the rotor 11 by stepping.

This rotating magnetic field generating means is mainly intended for cost reduction, and in many cases, the stators 13 and 1 are formed by pressing a flat plate member such as electromagnetic soft iron into a predetermined shape.
5, 16 and 18 are used, and the coil 21 is wound 1
A set of coil bobbins 19 is provided so as to be inserted into the magnetic pole teeth 20 formed integrally with each stator so that a closed magnetic circuit can be formed.

As described above, in the case of constructing the rotating magnetic field generating means, if the height H of the magnetic pole teeth 20 of each stator is set to be larger so that the generated magnetic field can act longer in the longitudinal direction of the rotor 11, It is known that the generated torque can be increased without changing the outer diameter of the rotor 11 and almost without lowering the frequency characteristic of the stepping motor.

However, each of the above-mentioned stators 13 and 1 is
In order to form 5, 16 and 18 by sheet metal press working, as shown in the development view of the stator manufacturing of FIG. 5, first, a hole 22 is formed in the central portion of the plate member 10, and this hole is formed. The magnetic pole tooth forming portion 20 is provided radially by centering the portion by shear press processing or the like. After that, the magnetic pole tooth forming portion 20 is obtained by bending the magnetic pole tooth forming portion 20 at a substantially right angle using a bending line 21 shown by a broken line and a solid line as a bending margin. Since the manufacturing is performed as described above, the height H of the magnetic pole teeth 20 cannot be set to be more than half the diameter D of the bending line 21.

In view of this, according to the method for manufacturing a stator of a step motor disclosed in Japanese Patent Publication No. 1-23747, the plate member 10 is preliminarily press-formed into a conical shape with the center portion of the plate member 10 as the apex, and the bending line 21 After the diameter D is made larger than the dimension on the flat plate member 10, the magnetic pole tooth forming portions 20 are radially provided with the above-mentioned apex as a center by shear press working, and then the magnetic pole tooth forming portion 20 is bent. The wire 21 is obtained by bending the wire 21 at a substantially right angle so that the height H of the magnetic pole teeth 20 can be set to be half or more of the diameter D of the bending line 21 on the flat plate member 10. There is.

Further, in Japanese Patent Publication No. 62-49815, a method of manufacturing a stator yoke for a small motor, the height H of the magnetic pole teeth 20 of the stator can be set to be larger, and the height H of the magnetic pole teeth 20 of the stator can be set larger than that of the motor. It has been proposed to increase the number of steps. According to this proposal, a flat plate member is first pressed into a bowl shape, then into a concentric circular shape, and finally, the side surface portion of the inner circumference circle is punched using a punch and a die to form a magnetic pole. Since it forms teeth, it is not necessary to radially provide magnetic pole tooth forming parts as compared with the above-mentioned method of causing magnetic pole teeth, so that a large number of steps of the stepping motor determined by the magnetic pole teeth can be set. Is.

[0008]

However, in the former case of the above-mentioned proposal, from the central part of the plate member to the apex, the conical shape is pressed, and from the apex, the magnetic pole tooth forming portion is radially sheared and pressed. At this time, there is a problem that a shear press work must be performed in a direction perpendicular to an inclined surface forming a conical shape, and a special press die for this is required.

In the latter proposal, a flat plate member is first pressed into a bowl shape, and then a plurality of press dies are gradually pressed into concentric circular shapes, and finally a punch and a die and a die for punching out magnetic pole teeth. There is a problem in that many steps are required as well as a set is required. Therefore, the stator manufacturing method of the present invention has been made in view of the above-mentioned problems, and the purpose thereof is that a special press die is unnecessary, a plurality of press dies and the like are unnecessary, and many steps are required. Even if it does not, it is an object of the present invention to provide a stator manufacturing method capable of increasing the generated torque without substantially lowering the frequency characteristic of the stepping motor.

[0010]

In order to solve the above-mentioned problems and to achieve the object, a stator manufacturing method by press molding of the present invention is a flat plate-shaped stator for a stepping motor having a plurality of magnetic pole teeth. A stator manufacturing method manufactured by press-forming a member, comprising: a hole forming step of forming a hole in a central portion of the plate-like member; A magnetic pole tooth machining step of forming a magnetic pole tooth forming portion for the magnetic pole tooth by radially providing the magnetic pole tooth forming portion around the periphery, and a dividing machining step of machining the common portion so as to be divided into each magnetic pole tooth forming portion, And a bending step of dividing the divided shape and then raising and pressing the magnetic pole tooth forming portion.

Further, preferably, after the bending step,
The method further comprises a rolling step of extending the tip of the magnetic pole tooth forming portion along the direction of the rotation axis of the stepping motor, and a shaping step of shaping and pressing the inner peripheral surface side of the magnetic pole tooth forming portion along an annular shape. .. Then, preferably, the dividing step is shearing or V-notch processing that does not generate punch residue.

[0012]

In each of the steps described above, a hole is formed in the central portion of the plate member in the hole forming step, and before and after the hole is formed, the hole is centered in the magnetic pole tooth machining process, and the shared portion is formed. It is possible to form the magnetic pole tooth forming part for the magnetic pole tooth by arranging it around the hole and then radially forming it, and before and after this process, the common part can be divided for each magnetic pole tooth forming part in the dividing process. And finally divide the divided shape in the bending step, then start up the magnetic pole tooth forming part and press it to bend it, and press the stator for the stepping motor having multiple magnetic pole teeth into a flat plate-shaped member. Manufactured from.

After the bending step, the tip end of the magnetic pole tooth forming portion is extended along the rotation axis direction of the stepping motor in the rolling step, while the inner peripheral surface side of the magnetic pole tooth forming portion is annularly formed in the shaping step. Orthopedic press processing. Then, the scrap is prevented from being generated in the dividing process.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a development view in which a stator for a stepping motor is manufactured by press forming a flat plate member.
In this figure, the plate member 1 uses a rolled plate having a large magnetic permeability (a thickness of around 1 mm) such as electromagnetic soft iron. As shown in the drawing, a regular pentagonal center hole portion 4 and this center hole portion 4 are used. The magnetic pole tooth forming portions 2 each having a radial shape of 5 are formed, and the space portions 5 formed between the magnetic pole tooth forming portions 2 are processed.

A shared portion 2a, which shares a part with the magnetic pole tooth forming portion 2, is formed around the central hole portion 4, and
In this shared portion 2a, a shearing process is carried out so that the magnetic pole tooth forming portion 2 can be divided into individual pieces on a line connecting the corner portion of the regular pentagonal central hole portion 4 and the apex portion of the space portion 5. Line 3
Are formed radially as shown. This shear line 3
As shown in FIG. 2A, which is a cross-sectional view taken along the line XX in FIG. 1, forms a V notch portion 3a in a V shape from both front and back surface sides of the plate member 1, or FIG. It may be previously sheared as shown in b).

It is not necessary to set the order of the steps for each processing described above, and all steps may be performed in one step. In the next bending step of the plate member processed as described above, the shear line portion 3 is divided, and then the magnetic pole tooth forming portion 2 is raised and pressed to be bent, which is illustrated in the side view of FIG. After having a plurality of magnetic pole teeth 20, the outer shape is sheared or bent to obtain a stator for a stepping motor.

Since the height H of the magnetic pole teeth 20 of the stator obtained through the above steps can be increased by the size of the portion where the common portion 2a is provided, the rotating magnetic field generating means using this stator can be increased. In a stepping motor that uses, the rotating magnetic field can be made to act in the longitudinal direction of the rotor for a long time, so the generated torque can be increased without changing the outer diameter of the rotor and almost without lowering the frequency characteristics of the stepping motor. become able to.

Next, referring again to FIG. 3, the rolling portion 6 is subjected to a rolling process in which the dimension E is rolled more than the shear line portion 3 shown by the broken line in the figure and the tip is shaped into an arc. If obtained, the height H of the magnetic pole teeth 20 can be further increased. Further, the magnetic efficiency can be further improved by shaping the inner peripheral surfaces of the magnetic pole teeth 20 facing each other into an arc shape before and after this rolling step or simultaneously with the rolling step.

In the embodiment described above, only the case where five magnetic pole teeth 20 are obtained has been described, but it goes without saying that the present invention is not limited to this, and the stator is used only for a stepping motor. Of course, all of them can be applied to the rotating magnetic field generating means.

[0020]

As described above, according to the present invention, the frequency characteristics of the stepping motor can be almost eliminated without the need for a special press die, the need for a plurality of press dies, and the need for many steps. It is possible to provide a stator manufacturing method capable of increasing the generated torque without reducing the torque.

[Brief description of drawings]

FIG. 1 is a development view of a stator according to an embodiment at a manufacturing stage.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a side view of a stator.

FIG. 4 is an exploded view of a stepping motor.

FIG. 5 is a development view of a conventional stator manufacturing stage.

[Explanation of reference numerals] 1 plate member, 2 magnetic pole tooth forming portion, 3 shear line portion, 4 central hole portion, 5 space portion, and 6 rolling portion.

Claims (3)

[Claims] 1. A method for manufacturing a stator, comprising manufacturing a stator for a stepping motor having a plurality of magnetic pole teeth by press-forming a flat plate-shaped member, wherein a hole is formed in a central portion of the plate-shaped member. And a magnetic pole tooth machining step of forming a magnetic pole tooth forming portion for the magnetic pole tooth by forming a common portion around the hole portion and providing a shared portion around the hole portion, and forming a magnetic pole tooth forming portion for the magnetic pole tooth. A dividing step of processing the common portion so that it can be divided for each magnetic pole tooth forming portion, and a bending step of dividing the divided shape and then press-up the magnetic pole tooth forming portion. Method of manufacturing stator. 2. A rolling step of extending the tip of the magnetic pole tooth forming portion along the direction of the rotation axis of the stepping motor after the bending step, and an inner peripheral surface side of the magnetic pole tooth forming portion being formed along an annular shape. The method of manufacturing a stator according to claim 1, further comprising a shaping step of shaping press working. 3. The method for manufacturing a stator according to claim 2, wherein the dividing step is shearing or V-notch processing that does not generate punch residue.