JPH05244754A - Magnetizing method for motor with rotation detecting device - Google Patents

Abstract

PURPOSE:To prevent the distribution of magnetic flux density of a sensor magnet for detecting the number of revolutions from being disturbed by the magnetizing work of a stator magnet. CONSTITUTION:At the time of magnetizing a stator magnet 6, the magnet 6 and a sensor magnet 21 are respectively fixed to a yoke 4 and rotating shaft before the magnets 6 and 21 are magnetized. After the magnets 6 and 21 are fixed, a magnetized S-pole 14 and a magnetized N-pole 15 are arranged around a motor housing 3 in a facing state and the magnets 6 and 21 are simultaneously magnetized by the magnetic forces of both poles 14 and 15. Since the magnet 21 is simultaneously magnetized with the magnet 6, the disturbing phenomenon of the magnetic flux density of the magnet 21 is avoided as a matter of course.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for magnetizing a motor with a rotation detecting device, and more particularly to a technique for magnetizing a magnet for a motor stator and a rotation detecting magnet for detecting the rotation of the motor.

[0002]

2. Description of the Related Art For example, as a drive device for a window regulator of an automobile, there is a case where a motor with a rotation detecting device in which a rotation speed sensor for detecting the rotation speed of the electric motor is integrally incorporated. ..

As a motor with a rotation detecting device used in such a drive device for a window regulator, a magnet fixed to the outer peripheral surface of the rotation shaft of the motor and a magnet fixed to the motor housing in the vicinity of the magnet. In some cases, a rotation speed sensor including a reed switch that generates a rotation speed signal in response to a magnetic force is used.

When incorporating such a rotation speed sensor into a motor housing, the magnet (hereinafter, referred to as a sensor magnet) is magnetized and adhered and fixed to the outer peripheral surface of the rotary shaft. Has been adopted.

When a stator magnet fixed to a motor housing (hereinafter referred to as a stator magnet) is magnetized before assembly of a motor component, the magnetic force of the stator magnet is attached to another motor component. Interfere with Therefore, a method of magnetizing the stator magnet after the components such as the armature are assembled in the housing is generally adopted.

[0006]

However, after the sensor magnet for the rotation speed sensor is mounted on the rotation shaft,
When the stator magnet is magnetized, the sensor magnet is influenced by the magnetic flux of the stator magnet depending on the position of the sensor magnet, and the magnetic flux density distribution of the sensor magnet is disturbed. As a result, the correct rotation speed signal is not output from the rotation speed sensor.

That is, when the stator magnet is magnetized, the S pole of the sensor magnet is accurately aligned with the N pole of the magnetized pole, and the N pole of the sensor magnet is accurately aligned with the S pole of the magnetized pole. At times, the magnetic poles of the sensor magnet become proper without being affected by the magnetic force of the stator magnet. As a result, the rotation speed sensor can output an accurate rotation speed signal.

However, for example, when the N pole of the sensor magnet faces the N pole of the magnetized pole and the S pole of the sensor magnet is arranged at a position corresponding to the S pole of the magnetized pole, the magnetic force of the stator magnet is To be affected,
The magnetic flux density distribution of the sensor magnet is disturbed.

Further, when each magnetic pole of the sensor magnet is deviated from the magnetic pole by 90 degrees, the magnetic flux density distribution of the sensor magnet is disturbed because the magnetic force of the stator magnet is further affected. As a result, the rotation speed sensor cannot generate an accurate rotation speed signal.

An object of the present invention is to provide a method of magnetizing a motor with a rotation detecting device which can avoid a phenomenon in which the magnetic flux density distribution of a sensor magnet for detecting the number of revolutions is disturbed by the magnetizing work of a stator magnet. Especially.

[0011]

A method of magnetizing a rotating device according to the present invention includes a rotating shaft rotatably fixed to a housing, an armature fixed to the rotating shaft, and a magnet arranged close to the armature. The stator magnet fixed to the housing, the rotation speed detection magnet fixed to the rotating shaft, and the rotation speed detection magnet are fixed close to the housing and rotate in response to the magnetic force of the rotation speed detection magnet. A magnetizing method for a motor with a rotation detecting device, comprising: a rotation speed detecting body for generating a rotation speed signal, wherein the stator magnet is fixed to a housing in a non-magnetized state, and the rotation speed detecting magnet is not The magnets are fixed to the rotating shaft in a magnetized state, and after the magnets are fixed, magnetized magnetic poles of different polarities are arranged around the magnets so as to face each other with the rotating shaft in between. Is, the magnets by the magnetic force of the magnetized poles is characterized in that it is magnetized simultaneously.

[0012]

According to the above-mentioned means, the stator magnet and the sensor magnet for detecting the number of rotations are not magnetized and are fixed to the designated positions. Then, magnetized magnetic poles are arranged around the stator magnet and the sensor magnet so as to face each other, and the stator magnet and the sensor magnet are magnetized at the same time by the magnetic forces of the magnetized magnetic poles. Therefore, both the stator magnet and the sensor magnet arranged on the N pole side of the magnetized pole are magnetized to the S pole, and the stator magnet and the sensor magnet arranged on the S pole side of the magnetized pole are both the N pole. Be magnetized by.

In this way, when the stator magnet is magnetized, it is possible to avoid the phenomenon that the magnetic flux density distribution of the sensor magnet for detecting the rotational speed is disturbed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a longitudinal sectional view showing a method of magnetizing a motor with a rotation detecting device according to an embodiment of the present invention, FIG.
(B) is an explanatory view for explaining the operation,
(A) is a front view showing a magnetization relationship, and (b) is a waveform diagram showing a magnetic flux density distribution characteristic of a sensor magnet for rotation speed detection.

In the present embodiment, the motor with a rotation detecting device to which the magnetizing method according to the present invention is applied has a motor 1 as a drive source and a rotation speed as a rotation detecting device for detecting the rotation of the motor 1. The sensor 2 is provided.

The housing 3 of the motor 1 is composed of a yoke 4 formed in a tubular shape with one end open, and an end bracket 5 covered with the opening of the yoke 4. On the inner circumference of the yoke 4, two stator magnets 6 forming field poles are fixedly arranged with a phase difference of 180 degrees in the circumferential direction. The stator magnet 6 is formed into an arc shape by using a ferrite type permanent magnet material.

A rotating shaft 7 is concentrically arranged in the yoke 4 and rotatably supported by bearings 8 and 9. An armature 10 is arranged in the middle of the rotating shaft 7 so as to face the stator magnet 6 and is fixedly mounted outside. A commutator 11 is fixedly mounted on one side of the armature 10 on the rotary shaft 7.

On the other hand, a brush holder stay 13 is arranged and fixed to the end bracket 5 so as to face the commutator 11. The brush holder stay 13 is made of resin and integrally molded into a substantially disc shape. ing. The brush 12 is held on the brush holder stay 13,
The brush 12 is in sliding contact with the commutator 11.

On the outer peripheral surface of the rotating shaft 7 in the vicinity of the commutator 11, a rotation speed detecting magnet (hereinafter referred to as a sensor magnet) 21 of the rotation speed sensor 2 is fixedly mounted. The sensor magnet 21 is formed in a circular ring shape by using a ferrite or rare earth permanent magnet material, and the ring-shaped sensor magnet 2
1 is fitted to a rotary shaft 7 and fixed by an appropriate means such as adhesion.

A reed switch 22 as a rotational speed detecting member is fixed to the brush holder stay 13 so as to face the position of the sensor magnet 21. The reed switch 22 cooperates with the sensor magnets 21 to form the rotation speed sensor 2.
A rotation speed signal is generated in response to the magnetic force of 1.

That is, in the rotation speed sensor 2, the reed switch 22 is turned on / off each time each sensor magnet 21 moves in the vicinity of the reed switch 22 as the rotation shaft 7 of the motor 1 rotates. It is configured to output a rotation speed signal according to ON / OFF.

Next, a method of magnetizing the stator magnet and the sensor magnet according to one embodiment of the present invention will be described.

First, when the motor 1 and the rotation speed sensor 2 are assembled, the stator magnet 6 is fixed to the inner peripheral surface of the yoke 4 in a non-magnetized state. The sensor magnet 21 is also not magnetized and is fixed to the outer peripheral surface of the rotating shaft 7.

After the assembly of the various components constituting the motor 1 and the rotation speed sensor 2 is completed, as shown in FIG.
4 and the magnetized magnetic pole 15 of the S pole are arranged to face each other with the rotating shaft 7 in between. The stator magnet 6 and the sensor magnet 21 are magnetized at the same time by the magnetic forces of the magnetized magnetic poles 14 and 15.

That is, as shown in FIG. 2A, the stator magnet 6 and the sensor magnet 21 arranged on the magnetized pole 14 side are both magnetized to the S pole and arranged on the magnetized pole 15 side. Both the stator magnet 6 and the sensor magnet 21 are magnetized to the N pole.

In this case, since the sensor magnet 21 is magnetized at the same time as the stator magnet 6, the phenomenon that the magnetic flux density distribution of the sensor magnet 21 is disturbed by the magnetic force when the stator magnet 6 is magnetized is inevitably avoided. It will be.

Therefore, the sensor magnet 21 of the rotation speed sensor 2 in this embodiment is magnetized in accordance with the magnetic flux density distribution as shown in FIG. 2 (b).

As described above, according to this embodiment, the phenomenon that the magnetic flux density distribution characteristic of the sensor magnet 21 is disturbed by the influence of the magnetic force of the stator magnet 6 is inevitably avoided. An accurate rotation speed signal can be generated from No. 2, which can contribute to the improvement of quality.

Moreover, since the stator magnet 6 and the sensor magnet 21 are magnetized at the same time, the magnetizing process can be simplified.

It is needless to say that the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the scope of the invention.

For example, the number of poles of the stator magnet and the sensor magnet is not limited to two, but may be three or more.

[0032]

As described above, according to the present invention,
Since the stator magnet and the sensor magnet for rotation speed detection are configured to be magnetized at the same time, it is possible to avoid the phenomenon that the magnetic flux density distribution of the sensor magnet for rotation speed detection is disturbed by the magnetic force of the stator magnet. The detection accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a method of magnetizing a motor with a rotation detecting device according to an embodiment of the present invention.

FIG. 2A is a front view showing a magnetization relationship, and FIG. 2B is a waveform diagram showing magnetic flux density distribution characteristics of a sensor magnet for detecting a rotation speed.

[Explanation of symbols]

1 ... Motor, 2 ... Rotation speed sensor (rotation detecting device), 3 ...
Motor housing, 4 ... Yoke, 5 ... End bracket, 6 ... Stator magnet, 7 ... Rotating shaft, 8, 9 ... Bearing, 10 ... Armature, 11 ... Commitator, 12 ... Brush, 13 ... Brush holder stay, 14, 15 ... Magnetic pole, 21 ... Sensor magnet, 22 ... Reed switch.

Claims (1)

[Claims] 1. A rotating shaft rotatably fixed to a housing, an armature fixed to the rotating shaft, a stator magnet arranged near the armature and fixed to the housing, and fixed to the rotating shaft. And a rotation speed detection magnet fixed to the housing in proximity to the rotation speed detection magnet and generating a rotation speed signal in response to the magnetic force of the rotation speed detection magnet. In a method of magnetizing a motor with a device, the stator magnet is fixed to a housing in a non-magnetized state, the rotation speed detection magnet is fixed to a rotating shaft in a non-magnetized state, and each magnet is fixed. After that, magnetized poles with different polarities are arranged around each magnet so as to face each other with the rotation axis in between, and each magnet is simultaneously magnetized by the magnetic force of each magnetized pole. Magnetizing method of the rotation detecting apparatus with a motor, characterized in that the magnetic.