JP2000262970A - Eccentric commutator, production of this commutator and flat coreless vibration motor using this commutator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify assembly by gaining the movement of a centroid with the commutator itself, thereby eliminating the need for separately arranging an eccentric member and facilitating the connection of the respective terminals of the armature coil and commutator of the eccentric rotor of a non-mold type. SOLUTION: The non-molded eccentric rotor is formed by using the eccentric commutator S1 which is formed by disposing a plurality of commutator pieces 1s to commutator base materials 1, 11 containing a high-density resin of >=3.5 in specific gravity in at least part thereof and formed to a noncircular shape when viewed from a plane and is disposed with connecting terminal parts 1a and 1a formed in a manner as to prevent the extension parts integral with the commutator pieces from overlapping on the air core armature by making at least a high density resin part eccentric. This rotor is used for a coreless motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric commutator used as a silent call means of a mobile communication device and to an improvement in an assembly structure of a small vibration motor using the eccentric commutator.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, an eccentric weight W made of a tungsten alloy is arranged on an output shaft S of a cylindrical DC motor M as a silent call means for a pager, a portable telephone or the like. There is known an apparatus which generates vibration by utilizing a difference in centrifugal force of the vibration.

However, in the case where the eccentric weight W is added to the conventional output shaft S, there is a design limitation such that the turning space of the eccentric weight W must be taken into consideration on a device such as a pager. However, there is a problem in cost because an expensive tungsten alloy is used.

For this reason, the present applicant has previously disclosed a cylindrical coreless type vibration motor in which the output shaft is eliminated and the built-in rotor is eccentric, as disclosed in Japanese Patent Application No. 2-309070 (US Pat.
No. 155).

[0005] Since the motor has no output shaft and no eccentric weight, it has been well received in the market because it is not subject to design restrictions, is easy to use, and has no danger during turning. Since it has three cylindrical coreless windings,
The problem that the number of parts and the number of processing steps increase is included.

In order to vibrate the rotor itself with an iron core type in place of the cylindrical coreless winding type, the applicant of the present invention has disclosed one of three salient pole type iron cores as disclosed in Japanese Patent Application No. 2-294482. Is proposed.

However, the two salient pole type iron core type as described above is suitable for a motor having a relatively large output with a large output, such as a massager, but is a portable device using a low voltage such as a portable terminal. In this case, the movement of the center of gravity is small and the amount of vibration is small, which is not suitable.

Further, the present applicant has previously disclosed USP-53410
As disclosed in Japanese Patent No. 57, an eccentric armature core formed by facing a rotor in which three salient poles made of a magnetic material are all biased to one side on a four-pole field magnet magnetized by NS alternately. We propose a small vibration motor equipped with it. Furthermore, there is one disclosed in Japanese Patent Application Laid-Open No. 9-261918 as a disclosure of a similar technical idea. However, in such a motor, since the three armature cores made of a magnetic material are biased to one side, the cogging torque (the force attracted to the field magnet) is large, so that the air gap is relatively large. As a result, the diameter of the motor itself cannot be reduced.

[0009]

In the motor having the built-in eccentric rotor as described above, the distance between the armature windings is reduced as the size of the rotor is reduced, so that the terminal of the rotor is prevented from damaging the armature windings. Connecting to the commutator is a very difficult technique. In particular, when the printed wiring board is a flat commutator as it is, and the terminal of the armature winding is directly raised and soldered and connected, it separates from the printed pattern due to the elasticity of the terminal and is easily soldered. I couldn't do it.
Further, since the commutator itself is usually a well-balanced circular one, the built-in type eccentric rotor has another problem that the number of components such as eccentricity enhancing members is increased.

A first object of the present invention is to use a commutator itself for a vibration motor by increasing the shift of the center of gravity by itself.
It is not necessary to arrange an eccentric member separately. That is, an object of the present invention is to provide an eccentric commutator that can be a vibration motor with a reduced number of parts. A second object of the present invention is to provide an eccentric commutator in which the strength of a commutator substrate having a specific shape is ensured. A third object of the present invention is to provide a configuration of an eccentric commutator that can easily connect each terminal by separating a terminal connection portion from an armature coil. A fourth object of the present invention is to make the eccentric commutator itself also serve as a bearing. The fifth of the present invention
The purpose of this is to use such an eccentric commutator,
An object of the present invention is to provide a vibration motor having a small number of parts and thus being advantageous in cost.

[0011]

Means for Solving the Problems The above-mentioned basic means for solving the problems is a commutator substrate comprising at least a portion of a high-density resin having a specific gravity of 3.5 or more as in the first aspect of the present invention. And a plurality of commutator pieces arranged at least, and at least a portion of the high-density resin is decentered. The specific means can be achieved by the invention described in claim 2 in which the extended portion integral with the commutator piece is also eccentric. Further, the commutator substrate is formed in a non-circular shape whose outer shape is eccentric as viewed from a plane, and the commutator substrate including a part of the commutator piece is reinforced with a high-density resin portion. It can be achieved by what is formed for use. Further, as in the invention as set forth in claim 4, the extension portion integral with the commutator piece can be achieved by projecting from the commutator base material toward the center of gravity to form a connection terminal portion. Still further, as in the invention as set forth in claim 5, the connection terminal portion can be achieved by having a notch at a position on the opposite side of the center of gravity so as not to overlap the armature coil when viewed from a plane. Furthermore, the commutator substrate has a sliding property of a dynamic friction coefficient of 0.4 (1.5 kg / cm2) or less and a sliding resin portion having a bearing hole at the center. You can achieve it. Such an eccentric commutator is formed by connecting a plurality of commutator bases made of a printed wiring board as in the invention as set forth in claim 7, and collectively setting them in a molding die, and setting the specific gravity of It can be manufactured by eccentrically molding a high-density resin of .5 or more and integrally molding it. A small vibration motor using such an eccentric commutator can be achieved by a motor having the eccentric commutator and an eccentric rotor composed of an armature coil disposed on the eccentric commutator, as in the invention of claim 8. . According to a ninth aspect of the present invention, the eccentric rotor can be achieved by integrating a plurality of air-core armature coils using a positioning guide arranged on the eccentric commutator.

According to the first aspect of the present invention, since the center of gravity can be moved by the commutator itself, it is possible to provide a small vibration motor that does not require any other eccentric member. Claim 2,
According to the means for achieving the object shown in FIG. 3, the amount of eccentricity can be further increased. According to the fourth aspect of the present invention, since the connection portion is separated from the armature coil, the soldering can be easily performed. According to the means for achieving the object, there is no need for a special bearing. According to the means for achieving the object, an eccentric commutator can be manufactured in large quantities at low cost. According to the means for achieving the object, an eccentric rotor can be easily configured. According to the means for achieving the object set forth in claim 9,
The air core armature coil can be accurately positioned and securely fixed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a plan view showing a first embodiment of the eccentric commutator of the present invention, FIG. 2 is a plan view of a flat coreless vibration motor using the eccentric commutator of FIG. 1, and FIG. FIG. 4 is a plan view showing an internal embodiment of the motor using an eccentric commutator according to a second embodiment of the present invention, and FIG. 5 is a third embodiment as a modification of FIG. FIG. 6 is a plan view showing an internal embodiment of the motor using the eccentric commutator of the embodiment, FIG. 6 is a vertical sectional view taken along line YX of FIG. 5, and FIG. FIG.

In FIG. 1, reference numeral 1 denotes an eccentric commutator substrate formed of a printed wiring board, which is formed in a fan shape which is expanded when viewed from a plane. The eccentric commutator S1 is formed by integrally molding the eccentric commutator base material 1 with a high-density, high-sliding resin 2 having a specific gravity of 6 so as to surround the eccentric commutator substrate 1 when viewed from a plane. The eccentric commutator substrate 1 is provided with nine commutator pieces 1s # provided with diagonal slits for spark prevention. Of the three commutator pieces on the side of moving the center of gravity, an armature coil described later is formed. It protrudes from the bottom of the half-moon as a terminal connection terminal 1a. The eccentric commutator substrate 1 further extends as a reinforcing portion 1b to the inside of both ends 2a of a half-moon shape formed of a high-density and high-slidability resin 2. Commutator piece 1s ‥‥
The commutator pieces 1s # are short-circuited every two pieces from the principle of rotation using the front surface, the back surface via a through hole, and the like. A bearing hole 1c is provided at the center of the eccentric commutator S1, and an eccentric commutator substrate 1 is held by a bank 1d formed of the high-density and high-slidability resin 2. The eccentric commutator 1 configured as described above is further provided with a second bank 1e for shifting the center of gravity on the outer periphery of the half-moon shape. As shown by the broken lines on the back side, air-core armature coil positioning and fixing pieces 1f, 1f described later are integrally molded with the high-density high-sliding resin 2. The high-density high-sliding resin 2 having a specific gravity of 6 has a volume resistance of about 9 KΩ because the metal powder is bound with polyamide, so that the resistance has entered between the commutator pieces. Effective in preventing sparks.

Next, a first embodiment of a flat coreless vibration motor using an eccentric commutator as described above will be described with reference to FIGS. 2 and 3. An air-core armature coil 3 formed by winding a self-fusing wire will be described. , 3 are fitted into the air-core armature coil positioning and fixing pieces 1f, 1f, and the armature coil terminal connection terminal 1a is inserted through a predetermined groove 1g so that the winding start and winding ends are not within the thickness of the rotor. And eccentric rotor R1 by dipping and soldering. The air core armature coils 3, 3 are preferably fixed by reflow using powder or solid epoxy. The one provided with such an eccentric rotor R1 is an axial gap type,
Driven by the flat magnet 4. Reference numeral 5 denotes a tin-plated steel plate bracket that holds the magnet 4 and serves as a magnetic path. A pair of brushes 7, 7 are rotatably mounted on a shaft J fixed to the center of the bracket 5 via a bearing hole 1c of the eccentric commutator S1 also serving as a bearing. Electric power is supplied to the armature coils 3 by sliding the eccentric commutator S1 at an opening angle of 180 °.

FIG. 4 shows a second embodiment of the eccentric commutator of the present invention, that is, reference numeral 11 denotes an eccentric commutator substrate formed of a printed wiring board, which is formed in a fan shape which is expanded when viewed from a plane. Have been. An eccentric commutator S <b> 2 is formed by integrally molding the eccentric commutator base material 11 with a high-density, high-sliding resin 22 having a specific gravity of 6 so as to surround the eccentric commutator base material 11 when viewed from a plane. The eccentric commutator substrate 11 has six commutator pieces 11s provided with oblique slits for spark prevention.
Are protruded from the bottom of the half-moon as armature coil terminal connection terminals 1a to be described later from the three commutator pieces on the moving side of the center of gravity. This eccentric commutator substrate 11
Is extended as a reinforcing portion 11b to the inside of both ends 22a of a half-moon shape formed of a high-density high-sliding resin 22. The commutator pieces 11s # short-circuit each of the opposing commutator pieces 11s # from the principle of rotation using the front surface, the back surface, and the like via through holes. A bearing hole 1c is provided at the center of the eccentric commutator S2, and the eccentric commutator substrate 11 is held by a bank 1d formed of the high-density and high-slidability resin 22. The eccentric commutator 11 thus configured is further provided with a second bank portion 1e for shifting the center of gravity on the outer peripheral portion of the half-moon shape, and the arrangement of the six commutator pieces 11s # at an opening angle of 120 °. As shown by broken lines on the back side, air-core armature coil positioning and fixing pieces 11f, 1
The portion 1f is integrally formed with the high-density and high-slidability resin 22. Then, the air-core armature coils 33, 33 formed by winding the self-fusing wire are fitted into the air-core armature coil positioning and fixing pieces 11f, 11f, and the winding starts and ends at predetermined positions so that the terminal is not within the thickness of the rotor. Groove 1
The eccentric rotor R2 is formed by winding around the armature coil terminal connection terminal 1a via g and dipping and soldering.

FIGS. 5 and 6 show a vibration motor using an eccentric commutator according to a third embodiment which is a modification of the above-described FIG. 4. The base material 111 of the eccentric commutator S3 is half a month when viewed from a plane. , And the armature coil terminal connection terminal 11a is provided on the side opposite to the center of gravity opposite to the above. These armature coil terminal connection terminals 1
1a is further provided with a notch a for latching. The position of the armature coil terminal connection terminal 11a does not overlap with the air-core armature coils 33, 33 when viewed from a plane, so that the terminal connection is facilitated. Other configurations are the same as those in the first and second embodiments, and thus the same reference numerals are given and the description thereof is omitted.
The brushes 8 and 8 have a sliding contact opening angle of 90 degrees, and the magnet 44 is four-pole magnetized alternately with N and S poles.

FIG. 7 is an explanatory view of the method of manufacturing the eccentric commutator shown in FIG. 5. The base 111 of the eccentric commutator S3 is formed in ten rows and two rows via a connecting portion r #, and the injection molding metal is used as it is. It is set in a mold and integrally molded with the high-density, high-sliding resin having a specific gravity of 6 to form a group of connected eccentric commutators and cut off as they are, or use air-core armature coils 33, 33
After disposing the eccentric commutator, the eccentric commutator is separated from the eccentric rotor assembly. It is needless to say that such a manufacturing method can be used in the other embodiments described above.

As the high-density (specific gravity) high-slidability resin, a resin having a specific gravity of 3.5 to 10 is selected in consideration of a balance between high specific gravity and high slidability. When used for a millimeter motor,
Those having a specific gravity of about 5 to 6 are preferred. In order to shift the center of gravity and gain weight, a specific gravity of about 12 can be used. However, in this case, since the amount of the metal powder is large, the volume resistance is about 400Ω and the spark extinction property is improved, but the sliding property is deteriorated, so that another resin or a porous metal oil-impregnated bearing is used at the center. Is good. The lower the volume resistance, the greater the spark elimination effect. However, when the volume resistance is 200 Ω or less, the current consumption increases, and when the volume resistance is 10 KΩ or more, the spark elimination effect tends to be weak. Although the above description has been made in the case of the star connection type, the delta connection can be achieved by changing the position of the brush or the position of the magnetic pole of the field magnet.

[0020]

The eccentric commutator according to the present invention and the small vibration motor using the eccentric commutator are constructed as described above, so that the commutator itself can move the center of gravity without requiring an eccentric member. Since each armature coil is non-molded, disconnection can be prevented even with an armature coil consisting of a thin wire, and each armature coil is separated from the terminal connection so that the terminal can be easily connected to the commutator. Also, the commutator can be easily assembled. The following specific effects can be exhibited. According to the first aspect of the invention, since the center of gravity can be moved by the commutator itself, it is possible to provide a small vibration motor that does not require any other eccentric member. According to the invention described in claims 2 and 3,
The amount of eccentricity can be increased. According to the fourth aspect of the present invention, since the terminals can be collectively dipped and soldered, the workability is improved. According to the fifth aspect of the invention, no special bearing is required. According to the invention as set forth in claim 6, since the spark elimination resistor is inserted between the commutator pieces, electric noise can be reduced. According to the seventh aspect of the invention, the eccentric commutator can be manufactured in large quantities at low cost. According to the means for achieving the object, an eccentric rotor can be easily configured. Claim 9
According to the means for achieving the object described in (1), the air-core armature coil can be accurately positioned and securely fixed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of an eccentric commutator of the present invention.

FIG. 2 is a plan view of a flat coreless vibration motor using the eccentric commutator of FIG. 1;

FIG. 3 is a vertical sectional view taken along the line YX of the motor.

FIG. 4 is a plan view showing an internal embodiment of the motor using an eccentric commutator according to a second embodiment of the present invention.

FIG. 5 is a plan view showing an internal embodiment of the motor using an eccentric commutator of a third embodiment as a modification of FIG.

6 is a vertical sectional view taken along the line YX in FIG. 5;

FIG. 7 is a plan view for explaining a method of manufacturing the same eccentric commutator.

FIG. 8 is a perspective view of a conventional small vibration motor.

[Explanation of symbols]

 1, 11, 111 Eccentric commutator base material 1s, 11s Commutator piece 1a, 11a Terminal connection portion 1c Bearing hole 1d Bank portion 1e Second bank portion 2, 22, 222 High-density high-sliding resin S1, S2, S3 Eccentric commutator 3, 33 Air-core armature coil 4, 44 Magnet 5 Bracket 6, Case 8, 88 Brush J axis H Housing

Claims (9)

[Claims] 1. A commutator base comprising at least a portion of a high-density resin having a specific gravity of 3.5 or more, and a plurality of commutator pieces arranged thereon. An eccentric commutator made eccentric. 2. The eccentric commutator according to claim 1, wherein an extension part integral with the commutator piece is also eccentric. 3. The commutator substrate is formed in a non-circular shape whose outer shape is eccentric when viewed from a plane, and a commutator substrate including a part of a commutator piece is used for reinforcing a high-density resin part. Or the eccentric commutator according to claim 2. 4. An extension part integral with the commutator piece protrudes from the commutator base material toward the center of gravity to form a connection terminal part.
An eccentric commutator according to any one of claims 3 to 4. 5. The eccentric rectifier according to claim 1, wherein the connection terminal portion has a cutout at a position on the side opposite to the center of gravity that does not overlap the armature coil when viewed from a plane. Child. 6. The commutator substrate has a dynamic friction coefficient of 0.4.
A slidable resin portion having a slidability of (1.5 kg / cm2) or less and having a bearing hole at the center.
An eccentric commutator according to claim 4. 7. A plurality of commutator substrates formed of a printed wiring board are connected to each other and formed, and these are collectively set in a molding die.
A manufacturing method of forming an eccentric commutator by eccentrically molding the high-density resin having the specific gravity of 3.5 or more and integrally forming the same. 8. A flat coreless vibration motor provided with an eccentric rotor comprising the eccentric commutator and a non-molded armature coil disposed on the eccentric commutator. 9. The flat coreless vibration motor according to claim 8, wherein the eccentric rotor is integrated by using a positioning guide in which a plurality of air-core armature coils are arranged on the eccentric commutator.