JPH0731123A - Stepping motor stator molding method - Google Patents

Abstract

(57) [Summary] [Purpose] A tapered surface is formed at the tip of the pole teeth of the stator, and the tapered surface of the tip of the pole teeth is
The present invention provides a stator for a stepping motor which is processed during the process of a progressive die for molding a stator from a plate material, and a molding method thereof. A long member 20 having a predetermined width is fed to a progressive die at a predetermined feed pitch to form a curved portion 21 corresponding to the pole tooth 11b at the center of the member, and the curved portion 2 is formed.
1. Form a punched hole 22 in the center of the No. 1 and punch a plurality of pole teeth 11b on the inner diameter side of the flange 11a around the punched hole 22 and bend the pole teeth 11b at right angles to form the pole teeth 11b. Tapered surface 13 inclined inward at the tip
A method for forming a stator, characterized in that

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of a stepping motor used for a drive source accompanied by a step operation of various electronic devices and a molding method thereof.

[0002]

2. Description of the Related Art Heretofore, this type of stepping motor has been basically based on a structure in which a rotor provided with a permanent magnet is rotatably supported on the inner diameter side of a stator assembly portion having windings, and used electronic devices and the like. There are more types.

By the way, in the stator of the stepping motor, a plate material cut into a predetermined width is formed through a continuous pressing process in which each plate is provided with individual dies. That is, as shown in FIG. 3, a stator 2 having a flange 2a and a large number of pole teeth 2b is formed by pressing a plate material. Next, as shown in FIG. 4, the stators 2 and 2 are combined into one set so that the pole teeth 2b and 2b are alternately arranged to face each other, and the outer peripheral portions of the stators 2 and 2 and the pole teeth are combined. The bobbin 3 is formed by molding between 2b and 2b with resin 4. Furthermore, as shown in FIG. 5, the stator assembly 1 is constructed by winding the coil 5 around the outer circumference of the bobbin 3.

[0004]

However, in the above-described conventional stator assembly, when the coil is wound around the bobbin, the tightening force by the winding is applied to the inner diameter side, so that the pole teeth of the stator protrude to the inner diameter side. Due to such deformation, it sometimes interferes with the rotor and becomes unrotatable.

An object of the present invention is to solve the problems of the above-mentioned conventional structure. In the taper surface of the pole tooth tip, the taper surface is formed at the tip of the pole tooth of the stator. In order to obtain a stator for a stepping motor and a method for forming the same, the stator is processed during the process of a progressive die for molding the stator from a plate material.

[0006]

In order to achieve such an object, according to the present invention, a long member having a predetermined width is fed to a progressive die at a predetermined feed pitch, so that a central portion of the member is provided. Forming a curved portion corresponding to the pole teeth, forming a punched hole in the center of the curved portion, punching a plurality of pole teeth on the inner diameter side of the flange centering on this punched hole, And a taper surface inclined inward is formed at the tip of each pole tooth.

[0007]

As described above, in the stator of the stepping motor and the method of forming the same according to the present invention, a tapered surface inclined toward the inside is formed at the tip of the pole teeth of the stator, and the taper surface of the tip of the pole teeth is formed by a member. Since the processing is performed during the process of the progressive die for forming the stator, the processing is easy, and the pole teeth of the stator are arranged alternately to face each other and the pole teeth are resin-molded to form a stator assembly section. Even in the case of the above configuration, the tapered surface formed at the tip of the pole teeth of the stator is held in a state of being embedded in the resin. Therefore, even if a tightening force is applied to the inner diameter side of the stator assembly by the winding, the tip of the pole tooth is not deformed such as protruding toward the inner diameter side, and interference with the rotor can be avoided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a stator assembly portion according to the present invention, and FIGS. 2 (a) to 2 (d) are explanatory views of a main portion showing a molding process of a stator according to the present invention. In the figure, reference numeral 10 denotes a stator assembly portion, and the stator 11 that constitutes this stator assembly portion 10 is first formed through a continuous pressing process at each stage while the plate material passes through the progressive die. Next, the set of stators 11 and 11
The pole teeth 11b and 11b are alternately combined so as to be arranged so as to face each other, and the outer peripheral portion of the stator 11 and 11 and the space between the pole teeth 11b and 11b are molded with the resin 14 to form a bobbin. Then, the stator assembly portion 10 is configured by winding a coil around the outer peripheral portion of the bobbin.

The molding process of the stator 11 is shown in FIG.
The description will be made based on (d) to (d). First, a long member 20 having a predetermined width cut from a plate material corresponding to the desired size of the flange 11a for forming the desired stator 11 is sequentially fed to the progressive die at the feed pitch P1. And
In a predetermined forming step, as shown in FIG. 2A, a curved portion 21 corresponding to the pole tooth 11b is formed at an angle θ at the center of the member 20. Next, as shown in FIG. 2B, the central portion of the curved portion 21 has a press-type protrusion 25.
Is punched out to form a punched hole 22 having a diameter m.

Next, a plurality of pole teeth 11b are punched out on the inner diameter side of the flange 11a with the hole 22 of the member 20 as the center, and as shown in FIG. The tooth 11b is bent at a right angle. At this time, the taper surface 13 inclined inward is formed at the tip of each pole tooth 11b. After that, as shown in FIG. 2D, the stator 11 is molded by separating the outer peripheral portion of the flange 11a from the member 20.

Further, the pair of stators 11 and 11 formed as described above are combined so that the pole teeth 11b of each stator 11 are arranged alternately opposite to each other, and the outer peripheral portion and the poles of each stator 11 are arranged. The space between the teeth 11b is molded with the resin 14 to form the stator assembly portion 10. By molding the resin 14, the tapered surface 13 formed at the tip of the pole teeth 11b of the stator 11 is formed by the resin 14.
It is kept in a state of being buried in.

Therefore, when the stator assembly formed by using the stator 11 molded according to the embodiment of the present invention, the coil is wound around the bobbin, so that the tightening force by the winding is applied to the inner diameter side. , The pole teeth 11 of the stator 11
It is possible to avoid interference with the rotor without causing deformation such as the tip of b protruding to the inner diameter side.

[0014]

As described in detail above, according to the present invention, a long member having a predetermined width is fed to a progressive die at a predetermined feed pitch, so that the central portion of the member corresponds to a pole tooth. Forming a curved portion, forming a punched hole in the center of the curved portion, punching a plurality of pole teeth on the inner diameter side of the flange centered on the punched hole, bend the pole teeth at a right angle,
When the inwardly tapered surface is formed at the tip of each pole tooth, the pole teeth of the stator are arranged alternately to face each other, and the pole teeth are resin-molded to form the stator assembly. However, since the tapered surface formed at the tip of the pole teeth of the stator is kept embedded in the resin, the tip of the pole teeth of the stator does not change even if the tightening force by the winding is applied to the inner diameter side. Does not deform such as protruding to the inner diameter side,
The stator capable of avoiding interference with the rotor can be molded by one mold, and the molding of the stator with stable press quality can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a stator assembly according to the present invention.

FIG. 2 is an explanatory diagram of a main part showing a molding process of a stator according to the present invention.

FIG. 3 is a cross-sectional view of a stator formed by a conventional process.

FIG. 4 is a perspective view of a bobbin obtained by resin-molding the stator of FIG. 3 in combination.

FIG. 5 is a sectional view showing a stator assembly having a conventional structure.

[Explanation of symbols]

 10 Stator Assembly Part 11 Stator 11a Flange 11b Pole Teeth 13 Tapered Surface 14 Resin 20 Long Member 22 Drain Hole

Claims (1)

[Claims] 1. A long member having a predetermined width is fed to a progressive die at a predetermined feed pitch to form a curved portion corresponding to a pole tooth at the central portion of the member, and punched at the central portion of the curved portion. A hole is formed, and a plurality of pole teeth are punched out on the inner diameter side of the flange centering on this punched hole, the pole teeth are bent at a right angle, and a tapered surface inclined inward is formed at the tip of each pole tooth. Stepping motor stator molding method.