WO2011108528A1

WO2011108528A1 - Motor

Info

Publication number: WO2011108528A1
Application number: PCT/JP2011/054600
Authority: WO
Inventors: 千曉西川; 素行岡田
Original assignee: 株式会社ファインテック
Priority date: 2010-03-02
Filing date: 2011-03-01
Publication date: 2011-09-09
Also published as: JP2011182564A

Abstract

The disclosed motor is able to increase the probability of a magnetic material being stopped at the boundaries of the north and south poles of a magnet and thereby prevent a coil stopping at a dead point. The motor (1) has: a central shaft (4); a rotating body (6), which rotates about the central shaft (4); substrates (2a, 2b), which are arranged so as to face the rotating body; a coil (7), which is provided at a location on either the rotating body or one of the substrates; a magnet (3), which is provided on the other location among the rotating body or substrates so as to face the coil, and is magnetised to have a plurality of poles around the circumference, centred on the central shaft; and a magnetic material (10), which is provided on the central shaft or the substrate so that the magnetic material (10) can face the magnet and is arranged on the central shaft side of the midpoint (11c) between the furthest point from the shaft (11b) and the closest point to the shaft (11a).

Description

motor

The present invention relates to a motor.

Conventionally, for example, a flat coreless vibration motor disclosed in Patent Document 1 is known. According to this flat type coreless vibration motor, the rotatable rotating body arranged so as to face the flat circular magnet fixed to the bottom of the motor is arranged so that three coils are fan-shaped. And it is integrally molded with the resin frame. The rotating body includes a commutator that rotates together with each coil. When the commutator contacts two brushes extending from the lower part of the case, the polarity of the three coils is alternately switched, and each time between the magnets. Since the attractive force and the repulsive force are generated, the rotating body rotates.

Further, in a flat motor including a single coil in the rotating body, the rotating body is provided with a magnetic body, and when the rotation of the rotating body is stopped, the magnetic body is positioned at the boundary between the N pole and the S pole of the magnet. There has been proposed a rotating body structure of a flat motor provided such that the motor is located at a startable position (see, for example, Patent Document 2).

JP-A-6-205565 Japanese Patent No. 3039857

However, according to the knowledge of the inventor of the present application, even if a magnetic body is provided in the rotating body, when the power supplied to the coil of the rotating body is turned off, the magnetic body provided in the rotating body is not connected to the N pole ( Alternatively, the central part of the S pole may be attracted to the central part of the N pole (or S pole) of the magnet and stop at the central part because the magnetic flux density is large.

At this time, even if the coil is installed at a position where the motor can be started when the magnetic body stops at the boundary between the N-pole and S-pole of the magnet, the coil is magnetized once the magnetic body stops at the center of the magnet. It stops so that it may overlap on the N pole (or S pole) of this (henceforth a dead point suitably). At this time, since the same attractive force or repulsive force is received from two adjacent S poles (or N poles), even if a current flows through the coil, the electromagnetic force applied to the coil is weak, and the torque at which the rotating body starts to rotate. This is not sufficient, leading to a decrease in motor startability. Also, when the rotating body stops at the dead point, the insulating portion of the commutator provided on the rotating body side is always stopped so as to contact the brush provided on the magnet side, that is, it is in a non-energized state, and eventually It becomes difficult to start the motor. That is, since the stop position of the magnetic body is unclear, there is a technical problem that it is difficult not to stop the rotating body at the dead point.

An object of the present invention is to provide a motor capable of increasing the probability of stopping a magnetic body at the boundary between the N pole and S pole of a magnet and thereby preventing the rotating body from stopping at a dead point.

In order to achieve the above object, a first feature of the present invention is that a central axis, a rotating body that rotates around the central axis, a substrate that is disposed to face the rotating body, and the rotation A coil provided on one of the body and the substrate, and the other of the rotating body and the substrate and provided so as to be opposed to the coil, and a plurality of poles in the circumferential direction about the central axis A magnet that is magnetized on the rotating body and the substrate, and is provided so as to be opposed to the magnet, and a position that is farthest from the central axis of the rotating body and a position that is closest to the magnet And a magnetic body disposed closer to the central axis than the center. Therefore, it is possible to increase the probability of stopping the magnetic body at the boundary between the N pole and the S pole of the magnet, thereby effectively preventing the rotating body from stopping at the dead point.

Preferably, the magnet is magnetized into a plurality of poles at substantially equal angles around the central axis, and the magnetic body has an angle that is 1/2 to 1 times the angle of one pole of the magnet. . Therefore, since a plurality of magnetic bodies can be formed on the rotating body, the freedom of selection of the number and position of the magnetic bodies is increased.

Also preferably, the magnetic body is bent with the central axis side as a concave. Therefore, the magnetic body provided in the rotating body is more concave than the rod-shaped or flat-plate-shaped magnetic body of the same volume, so that an angle can be gained, and the magnetic body is reliably stopped at the boundary between the north and south poles of the magnet. Can be made.

Preferably, the commutator is provided on one of the rotating body and the substrate, and is divided into a plurality of circumferential directions around the central axis, and the other of the rotating body and the substrate. And a brush provided so as to be in contact with the commutator, and the brush is disposed so as to contact the commutator when the rotating body is stopped. ing. Therefore, even when a current is supplied to the coil by contact between the commutator and the brush, that is, in a motor with a brush, the probability of stopping the magnetic body at the boundary between the N pole and the S pole of the magnet can be increased.

Further, preferably, it further includes a Hall sensor provided on either one of the rotating body and the substrate, and for switching the energization direction to the coil in accordance with the rotation of the rotating body. Therefore, a commutator and a brush are not provided, and a hall sensor that switches the energization direction to the coil is provided. That is, even in a brushless motor, the probability of stopping the magnetic body at the boundary between the N pole and the S pole of the magnet is increased. be able to.

According to the present invention, it is possible to increase the probability of stopping the magnetic body at the boundary between the N pole and the S pole of the magnet, thereby effectively preventing the rotating body from stopping at the dead point.

It is a longitudinal section showing an example of the motor concerning a 1st embodiment of the present invention. It is a back view which shows the rotary body at the time of the stop which concerns on 1st Embodiment of this invention. FIG. 5 is a back view showing the rotating body when the rotating body according to the first embodiment of the present invention is located at a dead point. It is a longitudinal cross-sectional view which shows an example of the motor which concerns on 2nd Embodiment of this invention. It is a back view which shows the rotary body at the time of the stop which concerns on 2nd Embodiment of this invention. It is a back view which shows a rotary body when the rotary body which concerns on 2nd Embodiment of this invention is located in a dead point.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the structure of the motor 1 and the rotating body according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view showing an example of the motor 1 according to the first embodiment of the present invention, and FIG. 2 is a rear view showing the rotating body at the time of stop according to the first embodiment of the present invention. It is the figure seen from the lower side of FIG. In FIG. 2, for convenience of explanation, the magnet is normally disposed on the commutator side of the rotating body, but is illustrated on the rear side of the rotating body.

In FIG. 1, the motor 1 is mounted on a mobile phone and configured to be able to notify the user of an incoming call or the like by its vibration. The motor 1 includes an upper substrate 2a, a lower substrate 2b, a magnet 3, a central shaft 4, a bearing 5, a rotating body 6, a coil 7, a commutator 8, a brush 9, and a magnetic body 10.

The upper substrate 2a is formed so as to include a disk and a cylindrical side plate extending from the circumferential surface of the disk, and the lower substrate 2b is formed in a substantially disk shape. When the upper substrate 2a and the lower substrate 2b are connected, the magnet 3, the rotating body 6, and other components of the motor 1 are accommodated in the space formed by the upper substrate 2a and the lower substrate 2b.

The magnet 3 is fixed inside the lower substrate 2b. As shown in FIG. 2, the magnet 3 is formed in a substantially disc shape (more precisely, a donut-shaped plate shape with a missing central portion), and is magnetized by being divided into a plurality of poles. One magnetized region including N and S poles is formed by one magnetized region that is divided and magnetized. In the first embodiment, the four-pole magnetized magnet 3 is shown in which four poles are divided into N poles and S poles alternately, but other numbers of poles (for example, 6 poles, 8 poles) are shown. Etc.) may be used.

The center shaft 4 is rotatably attached to a cylindrical bearing 5 provided at the center of the upper substrate 2a and the lower substrate 2b.

The rotating body 6 is formed in a substantially disk shape, and a single coil 7 is disposed inside the rotating body 6 so that both are integrally formed. The rotating body 6 is attached to the central shaft 4 and is configured to be rotatable with respect to the upper substrate 2a, the lower substrate 2b, and the magnet 3 by the rotation of the central shaft 4.

The bearing 5 is provided on the upper substrate 2a and the lower substrate 2b, and the rotating body 6 provided on the central shaft 4 is provided so as to be rotatable with respect to the upper substrate 2a and the lower substrate 2b. The structure may be such that the rotating body 6 is fixed to the substrate 2a and the lower substrate 2b, the rotating body 6 is provided on the bearing 5, and the rotating body 6 and the bearing 5 are rotatable with respect to the central shaft 4 (so-called fixed shaft structure). Further, in FIG. 1, the central shaft 4 is illustrated so as to penetrate the bearing 5, but the central shaft 4 may not penetrate the bearing 5 and the end portion of the central shaft 4 may not be exposed.

In the first embodiment, the coil 7 is provided on the rotating body 6 side and the magnet 3 is provided on the lower substrate 2b. However, as long as the coil 7 can rotate with respect to the magnet 3, It may have various aspects. For example, the coil 7 may be provided on the upper substrate 2a or the lower substrate 2b, that is, the substrate side, and the magnet 3 may be provided on the rotating body 6 side. At this time, the bearing 5 may be provided on the upper substrate 2a and the lower substrate 2b, and the rotating body 6 provided on the central shaft 4 may be provided rotatably with respect to the upper substrate 2a and the lower substrate 2b. May be fixed to the upper substrate 2 a and the lower substrate 2 b, the rotating body 6 may be provided on the bearing 5, and the rotating body 6 and the bearing 5 may be rotatable with respect to the central shaft 4.

As shown in FIG. 2, the coil 7 is a one-turn coreless coil having a shape substantially corresponding to the shape of the rotating body 6, and is disposed on both sides (that is, the point A side and the point B side) toward the central axis 4. The opening angle, that is, the central angle of the coil 7 is formed to be about 90 degrees.

In the first embodiment, the coil 7 is formed so that the central angle thereof is about 90 degrees, that is, approximately ¼ circular, but the shape of the coil 7 is not limited to this. The fact that the coil 7 has a substantially ¼ circle corresponds to the magnet 3 being divided into four poles and magnetized. That is, the central angle of the coil 7 is substantially the same as the central angle of one magnetized region where the magnet 3 is divided and magnetized. Therefore, when the magnet 3 is magnetized to four poles as in the first embodiment, the central angle of the coil 7 is formed at about 90 degrees. For example, when the magnet 3 is divided into 6 poles and magnetized, the coil 7 is preferably formed in a substantially 1/6 circle having a central angle of about 60 degrees. Note that the electrodes of a commutator 8 described later are also divided according to the central angle of the coil 7.

The commutator 8 is provided on the back surface side (that is, the lower substrate 2b side) of the crimped portion of the rotating body 6 and is formed in a disk shape. As shown in FIG. 2, the commutator 8 includes four electrodes obtained by dividing a circle into approximately four equal parts around the central axis 5 and a commutator insulating portion 8 a between adjacent electrodes. A shaft hole is formed at the center of the commutator 8 (a position equal to the rotation center of the rotating body 6), and the center shaft 4 is inserted into the shaft hole. Further, the commutator 8 has two electrodes facing each other in the diagonal direction connected to each other, one end of which is connected to the inner end of the coil 7 and the other electrode is connected to the outer end. Yes.

For example, two brushes 9 (only one is shown in FIG. 1 for convenience of description) are provided so as to extend inside the lower substrate 2b. One end of the brush 9 (that is, the side extending to the inside of the lower substrate 2 b) is connected to a power supply terminal (not shown) through which external power is supplied to the motor 1. The other end of the brush 9, that is, the brush contact portion 9 a is in contact with the commutator 8. The contact between the commutator 8 and the brush 9 supplies current to the coil 7 from an external power source. When the rotating body 6 rotates, the contact point between the commutator 8 and the brush 9 moves, and the polarity of the coil 7 is switched. Each time the polarity of the coil 7 is switched, an attractive force and a repulsive force are generated between the coil 7 and the magnet 3, so that the rotating body 6 continues to rotate.

The shape of the brush 9 may be changed to improve the contact characteristics with the commutator 8. As a suitable example, the contact state between the brush contact portion 9a of the brush 9 and the commutator 8 may be configured to be line contact. In the first embodiment, the commutator 8 is provided on the rotating body 6 side and the brush 9 is provided on the lower substrate 2 b side. However, as long as the coil 7 can rotate with respect to the magnet 3. In, you may have various aspects. For example, the commutator 8 may be provided on the upper substrate 2a or the lower substrate 2b, that is, the substrate side, and the brush 9 may be provided on the rotating body 6 side.

The magnetic body 10 is provided inside the rotating body 6. As shown in FIG. 2, the magnetic body 10 is disposed closer to the center axis 4 than the center 11 c between the position 11 b farthest from the center axis 4 and the nearest position 11 a in the rotating body 6.

The magnetic body 10 is formed of a thin round bar made of iron, and is disposed substantially parallel to the rotation direction (or reverse rotation direction) of the rotating body 6. In addition, the magnetic body 10 is not limited to a thin round bar, and may be a flat piece or a square bar having a rectangular cross section. Although the magnetic body 10 is disposed substantially parallel to the rotation direction, the magnetic body 10 may not necessarily be orthogonal as long as the N pole and the S pole can be generated on both sides of the magnetic body 10.

The magnetic body 10 is bent so that the central axis 4 side is concave. In this embodiment, the magnetic body 10 is formed in an arc shape. According to this structure, since the magnetic body 10 provided in the rotating body 6 is made concave rather than a rod-shaped or flat-plate-shaped magnetic body having the same volume, an angle can be obtained, and the N pole of the magnet 3 can be reliably It can be stopped at the boundary with the south pole.

Further, as shown in FIG. 2, the magnetic body 10 is formed with a central angle of about 60 degrees, but is not particularly limited. The frequency of the central angle of the magnetic body 10 is preferably 45 to 90 degrees. Therefore, a plurality of magnetic bodies 10 can be formed on the rotating body 6, so that the freedom of selection of the number and position of the magnetic bodies 10 is increased.

The center of the magnetic body 10 is arranged at a central angle of about 135 degrees from one side (that is, the point A side in the figure) in the rotational tangent direction of the coil 7. In the first embodiment, the central angle from the center of the magnetic body 10 to one side of the coil 7 is as long as the rotating body 6 does not stop at the dead point when the magnetic body 10 described later stops at the boundary. It may have various aspects. For example, the center of the magnetic body 10 is arranged at a center angle of about 45, 135 degrees, 225 degrees, or 315 degrees from one end of both ends (points A and B in the figure) in the rotational tangent direction of the coil 7. May be. Further, the magnetic body 10 may be provided in the air core 12 of the coil 7. In this case, the center of the magnetic body 10 has a central angle of about 45 degrees from one end of the coil 7 (ie, point A in the figure) and a central angle of about 45 degrees from the other end of the coil 7 (ie, point B in the figure). Placed in position.

Further, the rotating body 6 may be configured to include a plurality of magnetic bodies 10. In any case, the combination of the number and position of the magnetic bodies 10 can be arbitrarily selected as long as the above-described conditions for the arrangement positions of the magnetic bodies 10 are satisfied. In order to increase the centrifugal force when the motor 1 is used as a vibration motor, a weight or the like may be provided on the rotating body 6.

Next, the principle of rotation of the rotating body 6 will be described with reference to FIGS. FIG. 3 is a back view showing the rotating body when the rotating body 6 according to the first embodiment of the present invention is located at the dead point. Similarly to FIG. It is shown on the rear side.

As shown in FIG. 2, when the rotating body 6 is stopped, two brushes 9 extend from the lower substrate 2 b, and a brush contact portion 9 a provided at the tip of the brush 9 and the commutator 8 of the rotating body 6. The electrodes are in contact with each other. As described above, at this time, the magnetic body 10 is located on the boundary between the N pole and the S pole of the magnet 3, and one end of the coil 7 (that is, point A in the figure) overlaps with the N pole of the magnet 3, and the other end (that is, (Point B in the figure) overlaps the S pole of the magnet 3. When the switch is turned on in this state, a magnetic field is generated in the coil 7 as a current flows from the outside of the coil 7 to the coil 7 through the commutator 8 with which the brush contact portion 9a contacts. At this time, if the polarity of the magnetic field generated on the side of the coil 7 facing the magnet 3 (the front side in the drawing) is the south pole, the repulsive force becomes the same south pole as the magnet portion of the polarity S on the lower left side. On the other hand, since the magnet part with the polarity N on the lower right side attracts each other, a rotational force is generated in that direction (clockwise direction), and the rotating body 6 is started.

Further, when the rotating body 6 further rotates, the electrode adjacent to the commutator 8 contacts the brush contact portion 9a, so that a current in the direction opposite to the state shown in FIG. For this reason, a reverse polarity (N pole) is generated in the coil 7 on the side facing the magnet 3, repels the N pole on the lower side of the magnet 3, and rotation continues in the same direction.

Thus, according to the rotation of the rotating body 6, the coil 7 repeats the N pole and the S pole alternately and repeats repulsion and attracting with the magnet 3. Thereby, the rotating body 6 can continue to rotate. When rotating the rotating body 6 in the reverse direction (clockwise direction), the current supply direction may be reversed, or the winding direction of the coil 7 may be reversed.

Further, when the rotating body 6 is rotated clockwise (or counterclockwise) on the magnet 3 and then the power supplied to the coil 7 of the rotating body 6 is shut off, the rotating body 6 according to the first embodiment is used. With this configuration, as shown in FIG. 2, the center of the magnetic body 10 in the longitudinal direction is stopped in a state where it is located on the boundary line between the N pole and the S pole of the magnet 3. This is because, when the magnetic body 10 is positioned on the boundary line between the N pole and the S pole of the magnet 3, one end in the longitudinal direction of the magnetic body 10 is magnetized to the S pole by the influence of the magnet 3, and the other end is magnetized to the N pole. As a result, the magnet 3 and the magnetic body 10 are attracted to overcome the free rotation of the rotating body 6 and stop at that position. In this state, by keeping a large distance between the insulating portion 8a of the commutator 8 and the brush 9 (approximately 45 degrees as shown in FIG. 2), a non-energized state can be prevented. Therefore, the work accuracy of the highly difficult brush attachment process is not required.

As shown in FIG. 3, even if the center of the magnetic body 10 in the longitudinal direction is located at the center of the south pole of the magnet 3, that is, even if the rotating body 6 stops at the dead point, Since the attracting force attracted to the central portion where the magnetic flux density is large is almost the force in the rotation normal direction, the rotating body 6 eventually rotates counterclockwise from the position shown in FIG. 3 to the position shown in FIG. And become stable. That is, the configuration of the magnetic body 10 according to the first embodiment increases the probability of stopping the magnetic body 10 at the boundary between the N pole and the S pole of the magnet 3, and thus the rotating body 6 stops at the dead point. It can be effectively prevented.

As described above, in the brushed motor 1 according to the first embodiment, in any case, the probability of stopping the magnetic body 10 at the boundary between the N pole and the S pole of the magnet 3 is increased, and thus the rotating body 6 is used. Can be effectively prevented from stopping at the dead point.

Next, the configuration of the motor 1 according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a longitudinal sectional view showing an example of the motor 1 according to the second embodiment of the present invention, and FIG. 5 is a back surface showing the rotating body 6 when stopped according to the second embodiment of the present invention. FIG. 6 is a rear view showing the rotating body 6 when the rotating body 6 according to the second embodiment of the present invention is located at a dead point. 5 and 6, for convenience of explanation, the magnet 3 is normally disposed on the back side of the rotating body 6 (that is, the lower side of FIG. 4), but on the front side of the rotating body 6 (that is, the upper side of FIG. 4). Show. 4 to 6, the same reference numerals are given to the same portions as those in FIGS. 1 to 3, and description thereof will be omitted as appropriate.

As shown in FIG. 4, in the second embodiment, the coil 7 and the magnetic body 10 are provided on the lower substrate 2b, and the magnet 3 is provided on the rotating body 6 side. A semicircular ring-shaped weight 14 is disposed on the outer periphery of the magnet 3 on the rotating body 6 side. Therefore, the centrifugal force when the motor 1 provided with the rotating body 6 is used as a vibration motor can be increased.

A Hall sensor 13 that detects the rotational position of the rotating body 6 by detecting changes in the magnetic poles of the magnet 3 is installed inside the lower substrate 2b. The rotational position signal detected by the Hall sensor 13 is sent to a control unit (not shown) such as a controller, and based on this, the current to the coil 7 is appropriately switched to form a rotating magnetic field that drives the rotating body 6 to rotate. Is done. That is, the motor 1 according to the second embodiment is configured as a so-called brushless motor.

The arrangement position of the hall sensor 13 may have various modes as long as the rotation position of the rotating body 6 is detected, and particularly when the activation direction can be determined when the motor 1 is restarted from a stopped state. . For example, the Hall sensor 13 may be disposed at a position where the center of the Hall sensor 13 has a central angle of about 180 degrees from the center of the magnetic body 10 (that is, facing the magnetic body 10).

As shown in FIG. 5, in the second embodiment, the center of the coil 7 is arranged at each of central angles (clockwise direction) of about 60 degrees, 240 degrees and 300 degrees from the center of the magnetic body 10. However, the embodiment is not limited to this. For example, when the Hall sensor 13 is disposed so as to face the magnetic body 10, the center of the other coil 7 is located at a central angle (clockwise direction) of about 120 degrees from the center of the magnetic body 10. It may be arranged.

Also, a plurality of magnetic bodies 10 may be provided. For example, the two magnetic bodies 10 may be disposed at positions facing each other. In any case, the combination of the number and position of the coil 7 and the magnetic body 10 has various modes as long as the rotating body 6 does not stop at the dead point when the magnetic body 10 stops at the boundary. It's okay.

According to the configuration of the brushless motor 1 of the second embodiment, the probability of stopping the magnetic body 10 at the boundary between the N pole and the S pole of the magnet is increased as in the first embodiment described above, so that the rotating body It is possible to effectively prevent 6 from stopping at the dead point.

The motor according to the present invention can be used in a mobile phone for notifying a user of an incoming call or the like.

DESCRIPTION OF SYMBOLS 1 Motor

2a Upper board

2b Lower board 3 Magnet 4 Center shaft 5 Bearing 6 Rotating body 7 Coil 8 Commutator 8a Commutator insulation part 9 Brush 9a Brush contact part 10 Magnetic body

11a Inner edge

11b Outer edge

11c Center part 12 Air core part 13 Hall sensor 14 weights

Claims

A central axis;
A rotating body that rotates about the central axis;
A substrate disposed opposite the rotating body;
A coil provided on one of the rotating body and the substrate;
A magnet that is provided on the other side of the rotating body and the substrate so as to be opposed to the coil, and is magnetized in a plurality of poles in the circumferential direction around the central axis;
One of the rotating body and the substrate, provided so as to be able to face the magnet, and closer to the central axis than the center between the position farthest from the central axis and the closest position of the rotating body An arranged magnetic body;
Having a motor.
The magnet is magnetized into a plurality of poles at substantially equal angles around the central axis,
The motor according to claim 1, wherein the magnetic body has an angle that is 1/2 to 1 times the angle of one pole of the magnet.
The motor according to claim 1 or 2, wherein the magnetic body is bent with the central axis side being concave.
A commutator that is provided on one of the rotating body and the substrate and is divided into a plurality of circumferential directions around the central axis;
A brush provided on the other of the rotating body and the substrate and provided so as to be in contact with the commutator;
Further comprising
The motor according to any one of claims 1 to 3, wherein the brush is disposed so as to contact the commutator when the rotating body is stopped.
The motor according to any one of claims 1 to 3, further comprising a hall sensor provided on any one of the rotating body and the substrate and switching a direction of energization of the coil according to the rotation of the rotating body.