JPH08182298A - Stepping motor - Google Patents

Abstract

PURPOSE: To provide a stepping motor with low-noise and high-performance where corrosion resistance is improved by ensuring positive yoke washing and plating treatment and chemical polishing treatment after magnetic annealing and at the same time vibration when driving with a motor is prevented. CONSTITUTION: In a stepping motor with a rotor 1 having a permanent magnet 2 which is subjected to multiple-pole magnetization, stator yokes 4, 5, 6, and 7 having a plurality of comb-shaped pole pieces which are provided opposingly on the shaft of the rotor 1, excitation coils 10 and 11 which are provided outside the stator yokes 4, 5, 6, and 7, and a frame yoke 8 formed so that the stator yoke 4, 5, 6, and 7 and the excitation coils 10 and 11 are surrounded, a protrusion is provided at a flange part toward the protruding direction of the pole gears. Also, the protrusion of the stator yokes 4, 5, 6, and 7 can be elastically deformed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping motor, and more particularly to the shape of a stator yoke used in the stepping motor.

[0002]

2. Description of the Related Art A stepping motor is a permanent magnet rotor, a stator yoke having comb-shaped pole teeth provided on the rotor shaft, a magnetic excitation coil provided around the rotor yoke, and a cup-shaped member having an internal member interposed therebetween. It is composed of a frame yoke and the like, and in particular, a molded product such as a stator yoke and a frame yoke by press working is used. Therefore, at the time of assembly, these stator yokes and frame yokes need to be washed with the press oil adhered at the time of press working, and sometimes their surfaces are plated.

[0003]

Although a large amount of cleaning and plating treatment of these stator yokes and frame yokes is performed at once, especially when cleaning the stator yokes (usually an organic solvent is used), FIG. 9 and FIG. As shown in FIG. 10, the yokes are likely to overlap each other during transportation due to their shape, and if the yokes are washed as they are, the cleaning fluid cannot penetrate into the overlapped portions, so that the press oil remains attached, which causes a subsequent work process or a magnetic field. There arises a problem that the atmosphere in the smelting furnace is adversely affected. Similarly, even if the plating process is performed, the plating of the overlapped portion becomes incomplete, the corrosion resistance decreases, and rust is generated.

In order to avoid such an inconvenience, the overlapping yokes are separated at the time of cleaning or plating, but this is a very troublesome work and causes a cost increase. The same problem occurs in the chemical polishing process after the magnetic refining process.

By the way, a stepping motor has a stator yoke, a coil, and the like interposed in a frame yoke and is then pressed by a cap to be sealed. However, the dimension of such an interior member is set to be slightly smaller than the storage dimension of the frame yoke. , There is a little play with the frame yoke. Also, when assembling, the positioning is done by fitting the unevenness provided on the yoke and coil bobbin, but even if this fitting is done, there is a slight margin, and due to such play and fitting backlash etc. The members vibrate and generate noise. In addition, the vibration of the interior member may deteriorate the performance of the motor. For this reason, conventionally, when the motor was closed, the stator yoke and the excitation coil were strongly pressed, or the stator yoke and the excitation coil were integrally molded with resin to prevent vibration, but if the yoke and coil are pressed too hard, the coil bobbin Is deformed or the pole teeth of the yoke are deformed, the gap with the rotor is narrowed, and the rotor contacts with the rotor extremely, so that the rotor does not rotate, which adversely affects the constituent members. In addition, if the resin mold is integrated, the number of molding steps is newly added, which tends to increase the cost.

An object of the present invention is to solve the above problems, to ensure the cleaning and plating treatment of the yoke after press working and the chemical polishing treatment of the yoke after magnetic annealing to improve the corrosion resistance and to improve the motor resistance. It is an object of the present invention to provide a stepping motor with low noise and good performance, which prevents vibration during driving.

[0007]

That is, according to the present invention, a rotor (1) having a permanent magnet (2) magnetized in multiple poles, and a plurality of comb-shapes provided around the rotor (1) are provided. Stator yoke (4, 5, 6, 7) having pole teeth (a) of
The magnetic excitation coils (10, 11) mounted on the stator yokes (4, 5, 6, 7) and the stator yokes (4, 5,
6, 7) and a frame yoke (8) formed so as to surround the magnetic excitation coils (10, 11), a pole tooth (a) is provided on the flange portion (c).
The protrusion (b) is provided toward the protruding side of the.

Further, in the present invention, the protrusion (b) of the flange portion (c) of the stator yoke (4, 5, 6, 7) is elastically deformable. Further, the projection (b) is preferably formed by reducing the thickness of the base portion (B).

[0009]

[Operation] With the above configuration, in the present invention, when the protrusion is provided on the flange portion of the stator yoke, cleaning, plating,
Alternatively, even if the stator yokes are overlapped with each other during the chemical polishing process, the protrusions create a gap between the stator yokes, so that the flange portions do not adhere to each other, and reliable cleaning, plating process, and chemical polishing process can be performed.

Further, if the projection provided on the flange portion is an elastically deformable projection, this projection presses the interior member with an appropriate spring load at the time of assembly and absorbs play and shake between the members, Vibration when driving the stepping motor is greatly reduced and noise is also reduced.

[0011]

1 is a sectional perspective view showing the structure of a stepping motor according to the present invention. A rotor 1, which is a rotating body, is composed of a ring-shaped permanent magnet 2 that is magnetized in multiple poles in the circumferential direction and a shaft 3 that supports the magnet, and a stator is formed so as to surround the outside thereof. This stator is a permanent magnet 2
, Stator yokes 4, 5, 6, 7 having four comb-shaped pole teeth, which are vertically arranged to face each other, and two upper and lower exciting coils 10, 11 mounted on the outside thereof, and these members. It is composed of a cup-shaped frame yoke 8 which interposes between the pole yokes and a cap 9 which seals the frame yoke 8. The pole teeth of the stator yokes 4 and 5 and the pole teeth of the stator yokes 6 and 7 are 90 ° to each other. It is arranged to have an electrical angle of.

FIG. 2 is a perspective view showing an embodiment of the stator yokes 4, 5, 6, 7 and FIG. 3 (a) is a front view thereof.
(b) is an AA sectional view. In the figure, a is a pole tooth arranged in the circumferential direction, c is a flange portion, and b is a protrusion provided on the flange portion. The details are shown in FIGS. 4 (a) and 4 (b). The protrusion b is punched into a wedge shape by press working as shown in FIG. 4 (a) (the punched portion is shown by a diagonal line A), and then, shown in FIG. 4 (b). Thus, the dotted line portion is formed by bending the pole tooth a toward the protruding side. or,
As will be described later, it is more convenient to make this protrusion b an elastically deformable protrusion. Therefore, as shown in FIG. 4 (c), the thickness of the bending base B of the protrusion b is thinned by chamfering or drawing. Also used. The shape of the protrusion b is not limited to the shape shown in FIG. 4, but may be any shape as long as it can repel, and a hook-like shape as shown in FIG. In this case, after punching by press working (the punching portion is shown by diagonal lines A), two dotted portions are bent to the protruding side of the pole tooth a as shown in FIG. 5 (b). This shape has a spring effect more than that shown in FIG. 4, but the one having a thinner bending base B to enhance elasticity is shown in FIG. 5 (c).
Is.

As described above, in the manufacturing process, the above-mentioned stator yokes 4, 5, 6, 7 are collectively subjected to a large amount of cleaning, plating treatment, or chemical polishing treatment. The direction of the peaks and valleys of the tooth a is shown in FIG.
Even if it is positioned as shown in (a) or (b), by using the stator yoke like this embodiment provided with the protrusion b, it is possible to obtain the conventional product shown in FIG. 10 (a) or (b). Therefore, it is possible to surely prevent the inconvenience that the flange portions c are in close contact with each other and a processing defect occurs.

That is, even if the peaks of the pole teeth a of the lower stator yoke enter the valleys of the upper stator yoke and the stator yokes try to overlap with each other, the lower stator yoke as shown in FIG. Since the protrusion b formed on the lower end abuts on the lower surface of the flange portion c of the upper stator yoke, a gap corresponding to the height of the protrusion b is formed between the flanges c, and the stator yoke is repulsed by the protrusion b. Will be separated from each other. Therefore, since the processing liquid permeates through the gap, the predetermined processing can be surely performed on the surface of the flange c.

Next, the anti-vibration effect when the protrusion b has elasticity will be described. Although not shown, generally, the stator yoke 4 is used for positioning and assembling the stepping motor.
The convex portions, the concave portions, the holes, etc. provided in 5, 6, 7 are fitted to the corresponding convex portions, the concave portions, the holes, etc. of the coil bobbins 10, 11, and they are closed by pressing them with the cap 9. In addition, as shown in FIG.
The elastically deformable protrusions b provided on the flange portions c of 5, 6, and 7 firmly press the coil bobbin 12 with a constant spring load, and due to the elasticity, vibration caused by play between the coil bobbin 12 and play with the frame yoke 8, etc. To effectively absorb
Rotational vibration and noise generated when the motor is driven will be greatly reduced. Further, even if the flange portion c is provided with the projection b, the elastic projection b does not hinder the assembly because it bends while pressing the coil bobbin 12 during assembly.

In this embodiment, the stator yokes 4, 5, 6,
Although the one protrusion b is provided on the flange portion c of No. 7, the formation position and the number thereof are not limited to this, and it is effective if at least one protrusion b is provided. Therefore, the protrusions b may be provided effectively as appropriate according to the size and output of the motor. For example, as shown in FIG. 8, the protrusions b are formed on the flange portion c of the stator yokes 4, 5, 6, and 7 at equal intervals. With such a structure, the assembled stator yokes 4, 5, 6,
7. The exciting coils 10 and 11 can be made more stable.

[0017]

As described above, according to the present invention, since the protrusions are provided on the flange portion of the stator yoke, the yokes are joined together during cleaning or plating of the stator yoke or chemical polishing after magnetic annealing. Since they do not overlap each other, the cleaning effect, plating treatment effect, or chemical polishing treatment effect becomes reliable, and the corrosion resistance of the component members is improved, and the time and effort required to separate the overlapping yokes during transport and processing as in the past Also, the manufacturing man-hours can be significantly reduced. or,
Due to this protrusion, a large amount can be collectively conveyed, which also contributes to reduction in the number of steps.

Further, according to the present invention, since the protrusion is elastically deformable, the inner member of the stepping motor is securely fixed by the spring load, and the play and play between the members are absorbed to drive the motor. Rotational vibration, noise, etc. are significantly reduced, and the performance of the stepping motor is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view showing a configuration of a stepping motor according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the stator yoke.

FIG. 3 is a diagram showing an embodiment of the stator yoke,
(a) is a front view and (b) is a sectional view taken along the line AA '.

4A is an enlarged view of a part of a stator yoke, FIG. 4B is a sectional view taken along the line AA ′, and FIG.
It is a -A 'sectional view.

5A is a partially enlarged view of a stator yoke different from FIG. 4, FIG. 5B is a sectional view taken along the line AA ′, and FIG. 5C is a sectional view taken along the line AA ′ when the elasticity of the protrusion is enhanced. It is a figure.

FIG. 6 is a partially enlarged front view of the flange portion when the stator yokes according to the present invention overlap each other.

FIG. 7 is a partial front view showing how a coil bobbin is fitted to the stator yoke.

FIG. 8 is a view showing a stator yoke different from that shown in FIG.
Is a front view and (b) is a sectional view taken along line AA '.

FIG. 9 is a front view showing a positional relationship in which conventional stator yokes are overlapped with each other, (a) is a case where the pole teeth are located in the same direction, and (b) is a case where the pole teeth are opposed to each other.

FIG. 10 is a perspective view showing a case where conventional stator yokes are overlapped with each other, (a) shows a case where pole teeth are located in the same direction, (b) shows
Shows the case where the polar teeth face each other.

[Explanation of symbols]

 1 rotor 2 permanent magnets 4, 5, 6, 7 stator yoke 8 frame yoke 10, 11 magnetic excitation coil a pole teeth b protrusion c flange portion B protrusion base

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutaka Honma 5-36-11 Shinbashi, Minato-ku, Tokyo Within Fuji Electric Chemical Co., Ltd. (72) Hirofumi Nakano 5-36-11 Shinbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd.

Claims (3)

[Claims] 1. A stator yoke having a rotor (1) having multi-pole magnetized permanent magnets (2) and a plurality of comb-shaped pole teeth (a) provided outside the rotor (1). (4,
5, 6, 7) and the stator yoke (4, 5, 6, 7)
Magnetic excitation coil (10, 11) mounted on the stator yoke, the stator yoke (4, 5, 6, 7) and the magnetic excitation coil (10,
A stepping motor comprising a frame yoke (8) formed so as to surround 11), wherein the flange portion (c) is provided with a protrusion (b) toward the protruding side of the pole tooth (a). 2. The stepping motor according to claim 1, wherein the projection (b) of the flange portion (c) of the stator yoke (4, 5, 6, 7) is elastically deformable. 3. The stepping motor according to claim 2, wherein the projection (b) of the flange portion (c) is formed by thinning the wall thickness of the base portion (B).