JP2000224823A - Small-sided vibration motor equipped with eccentric rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify assembly of a commutator by facilitating wire connection of the commutator with each terminal of an armature coil of a built-in type non-mold eccentric rotor. SOLUTION: An armature coil terminal wire connection part of a commutator 6 arranged in a non-mold eccentric rotor is formed of protrusions X, Y, Z capable of suspension fixing and recessed parts, and installed on the anti-centroid side. The eccentric rotor consists of a nonmagnetic material salient-pole 4 for emphasizing eccentricity and an armature coil 51 wound around two magnetic material salient-poles. The nonmagnetic material salient-pole 4 is composed of high specific gravity sliding synthetic resin for emphasizing eccentricity arranged between the two magnetic material salient-poles 43 which are made to face each other by making the arrangement opening angle of blades receiving the magnetic flux of a field magnet eccentric. The terminal wire connection part of the armature coil is exposed on the nonmagnetic material salient-pole, and the commutator is molded integrally in the exposed thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small vibration motor used as a silent call means of a mobile communication device, and more particularly to an improvement in an assembly structure of a small vibration motor having an eccentric rotor which does not require an eccentric weight.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, 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 number of parts and the number of processing steps are increasing, and the problem of cost 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. Are unsuitable because the center of gravity moves little due to their small size and the amount of vibration tends to be insufficient.

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.

[0010] A first object of the present invention is to create a vibration by only an eccentric armature and focus on the structure of a built-in, non-molded eccentric armature. An object of the present invention is to provide a configuration that can easily connect each terminal of a coil to a commutator. A second object of the present invention is to provide a structure in which the winding of the armature coil can be easily performed while having an eccentric armature core in which all the salient poles are biased to one side. A third object of the present invention is to provide a configuration that can easily assemble a commutator. A fourth object of the present invention is to provide a low-profile eccentric rotor, that is, a thin vibration motor.

[0011]

According to the first aspect of the present invention, there is provided an eccentric structure in which at least an armature coil portion is eccentric and non-molded, and a commutator is provided. A small-sized vibration motor including a rotor, a field magnet that applies a magnetic field to the eccentric rotor, a housing that houses the field magnet, a shaft that supports the eccentric rotor, and a brush that slides on the commutator. The armature coil terminal connection portion of the armature can be hooked and provided on the side opposite to the center of gravity. The specific means for enabling the locking can be achieved by means of protrusions and recesses as in the inventions as set forth in claims 2 and 3. As a more specific configuration, as in the invention shown in claim 4, the eccentric rotor has two magnetic salient poles eccentrically opposed to each other by eccentrically arranging an opening angle of a blade receiving a magnetic flux of a field magnet, and A nonmagnetic salient pole for eccentricity enhancement made of a high specific gravity slidable synthetic resin having a specific gravity of 5 or more, which is arranged between the magnetic salient poles so as to hold the magnetic salient pole; and at least two magnetic salient poles And an armature coil wound around the armature coil. It is preferable that at least a part of the commutator is formed integrally with the non-magnetic salient pole so that an armature coil terminal connection portion is exposed. Further, it is preferable that at least a part of the commutator is accommodated at least within a thickness of the nonmagnetic salient pole. The armature coil wound around the at least two magnetic salient poles and the outer diameter portion of the terminal portion of the commutator may be configured so as not to overlap when viewed from a plane. Can be achieved.

According to the means for achieving the object set forth in the first aspect, since the opposite center of gravity is opposite to the armature coil, the terminal can be easily hooked, and since there is a sufficient blank space, the soldering can be facilitated. . According to the means for achieving the object described in claims 2 and 3, even if the commutator has a circular outer shape, the commutator can be reliably engaged. According to the fourth aspect of the present invention, the cogging torque is offset and reduced by the two magnetic salient poles facing each other, and the displacement of the center of gravity can be increased by the eccentricity enhancing non-magnetic salient poles. According to the means for achieving the object, a commutator can be easily assembled. According to the sixth and seventh aspects of the present invention, the rotor can be made thinner, so that a low-profile motor can be obtained.

[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 cross-sectional view of a main part of a small vibration motor having an eccentric rotor according to a first embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of the inside of the motor of the first embodiment. Is an explanatory view of the operation principle of the embodiment,
FIG. 4 is a cross-sectional view of a main part of a second embodiment of the motor of the present invention, FIG. 5 is a vertical cross-sectional view of the inside of the motor of the second embodiment, and FIG. It is a principal part longitudinal cross-sectional view of the modification of a component.

In FIGS. 1 and 2, reference numeral 1 denotes a ring-shaped field magnet made of rare earth plastic, which is alternately magnetized into N and S equally into six poles. Reference numeral 2 denotes a casing made of a tin-plated steel plate that holds the field magnet 1 and serves as a magnetic path. Reference numeral 3 denotes an eccentric core made of a single silicon steel sheet. The two blades a and b arranged opposite to each other have an opening angle slightly larger than the field magnetic pole, and the two blades a and b as a whole are viewed from a plane. And the two magnetic salient poles 3a, 3b (winding portions) integrated with each blade a, b, respectively. ) Is such that an armature coil described later can be easily wound at a position shifted from the center of each of the blades a and b so as not to be in the radiation direction from the center of the core and at a position eccentric from the center of the core. It is eccentric with an opening angle of 180 degrees in parallel with the center line. For this reason, since the slot can be formed to have a width equal to or greater than the winding width, the armature coil can be easily wound, and aligned winding can be performed, so that the space factor of the coil is improved. And these two magnetic salient poles 3
The eccentric armature core 34 is constituted by the non-magnetic salient poles 4 for eccentricity enhancement disposed between a and 3b. The non-magnetic salient pole 4 is made of a highly slidable resin having a density (specific gravity) of 5 or more and also serves as a bearing. The non-magnetic salient pole 4 for emphasizing eccentricity has a hinge shape. Here, a bearing hole 4a is formed here, and a position at the time of assembly is determined by a guide hole e provided in the eccentric core. This eccentric armature core 34
The armature coils 51 and 52 are further wound around salient poles 3a and 3b made of a magnetic material via a coating layer (not shown), and the anti-center of gravity of the flat commutator 6 made of a printed wiring board attached thereto. The respective ends of the armature coil end connection portions x, y, and z provided on the side outer periphery are wound and soldered and connected to form the eccentric rotor R1. Here, at least one side is formed as a half through hole as a means that can be hooked, so that the connection can be securely made on the front and back, and the tip is formed with a divergent projection so that the terminal does not come off. Therefore, each armature coil 51, 52 wound on the center of gravity side
, The distance of the terminal wiring of the armature coil becomes longer, and it can be easily wound around the armature coil terminal connection portions x, y, z composed of the divergent projections. Then, as can be determined from the drawing, the soldering by the soldering iron can be easily performed by utilizing the blank space on the side opposite to the center of gravity. Further, the blade 4 of the nonmagnetic salient pole 4
Each of the blades a at the tips of the front magnetic salient poles 3a and 3b is formed by utilizing the axial space around which the armature coils 51 and 52 are wound in order to increase the weight of the nonmagnetic salient poles themselves. , B
Are partially superimposed.

As shown in FIGS. 1 and 2, the motor using such an eccentric rotor R1 has a shaft J fixed to a bracket 7 constituting a housing H together with the casing 2, the non-magnetic non-magnetic member serving also as a bearing. The armature coil 51 is rotatably mounted via the bearing hole 4a of the body salient pole 4, and the pair of brushes 8, 8 disposed on the bracket 7 is brought into sliding contact with the flat plate commutator 6 at an open angle. , 52 are supplied with electric power. Here, the flat commutator 6 is integrally formed when the non-magnetic salient pole 4 is formed so as to be within the thickness of the non-magnetic salient pole 4, and as shown in FIG. Commutator pieces 6a, 6 divided into equal parts
b, 6c, 6d, 6e, 6f, 6g, 6h, and 6i, and between every two commutator segments 6a-6d-6g, 6b-
Electrode patterns Pa, Pb, and Pc that short-circuit 6e-6g and 6c-6f-6i are formed by printing, and the winding start terminals of the armature coils 51, 52 are commutator pieces 6a, 6
The end-of-winding terminals are collectively connected to the armature coil terminal connection portions x and y of b, and connected to the armature coil terminal connection portion z of the commutator piece 6c, respectively, in a star connection system. The flat commutator 6 may be adhered later without forming it integrally when forming the nonmagnetic salient pole 4.

Next, the principle of rotation of the first embodiment will be described with reference to FIG. Now, when a DC voltage is applied to the pair of positive and negative brush pieces 8 and 8 by a required power supply (not shown), first, an eccentric rotor composed of armature coils 51 and 52, magnetic material salient poles 3a and 3b, and a commutator 6 is provided. When R1 is at the position shown in FIG. 7A (0 °), the armature coil flows in the direction of the arrow, the salient poles 3a and 3b are magnetized to N and S, respectively, and the salient pole 3a is attracted to the S1 pole of the field magnet. And is repelled from the N1 pole, generating torque in the direction of arrow A. Since the salient pole 3b is magnetized to the S pole, it is attracted to the N2 pole of the field magnet and repelled from the S1 pole, so that torque is also generated in the direction of arrow A. When the rotation advances to the position shown in FIG. B (30 °), the armature coil 5 of the salient pole 3a is de-energized, and an N pole opposite to the S pole of the salient pole 3b is generated. Since it is attracted from the S1 pole of the magnet, even if the rotation is stopped at this position, the starting becomes easy. When the rotation further proceeds and reaches the position c (60 °) in the same figure, current flows in the opposite direction, but the position of the field magnet is also reversed, and torque is generated in the direction of arrow A to rotate. No counter torque which hinders rotation occurs at other positions. Therefore, as long as power is supplied, the power is switched cyclically and the rotation is continued. Although not shown, it is a matter of course that the delta connection type armature coil may be formed by changing the position of the brush with respect to the field magnet. Needless to say, the shape and width of the blade of each salient pole are considered to be the best in design.

FIG. 4 shows a second embodiment of the motor according to the present invention. More specifically, reference numeral 1 denotes a ring-shaped field magnet made of a rare earth plastic, which is alternately magnetized into N and S equally equally into six poles. I have. Reference numeral 2 denotes a casing made of a tin-plated steel plate that holds the field magnet 11 and serves as a magnetic path. Reference numeral 33 denotes an eccentric core made of two silicon steel plates, which has two blades aa and bb arranged opposite to each other with an opening angle slightly larger than the field pole and as a whole two blades aa and bb viewed from a plane. Are formed so as to be within 4 poles + N of the magnet (N is a non-magnetized portion), and each blade aa, b
The two salient poles 33a, 33b (winding portions) integral with b are positioned so as not to be in the radiation direction from the center of the core and at positions deviated from the centers of the blades a, b, and eccentric from the center of the core. The armature is eccentric so that an armature coil described later can be easily wound. The armature coils 53, 54 are wound around the magnetic material salient poles 33a, 33b of the eccentric core 33 via coating layers (not shown) so that commutators, which will be described later, do not overlap when viewed from a plane. Has been turned. An eccentric armature core 43 is constituted by the nonmagnetic salient poles 44 arranged between the two salient poles 33a and 33b. The non-magnetic salient pole 44 is also made of a highly slidable resin having a density (specific gravity) of 5 or more and also serves as a bearing for enhancing eccentricity, and a bearing hole is formed at the center of the non-magnetic salient pole 44. The position at the time of assembly is determined by a guide hole e provided in the eccentric core. In addition,
As the high slidability resin having a density (specific gravity) of 5 or more, a resin having a specific gravity of 5 to 10 is selected in view of a balance between high specific gravity and high slidability.

The eccentric armature core 43 has a blade 44b of a nonmagnetic salient pole 44 and an air-core armature coil 45.
Is wound to form a coreless type. A commutator 66 made of a printed wiring board is integrated around the bearing hole 44a at the center of the nonmagnetic salient pole 44. The commutator 66 is divided into nine equal parts as in the above-described embodiment, and is made of a commutator piece whose sliding surface is plated with a noble metal. Semi-through hole (outside cutout)
Recess x that can be hooked to the armature coil terminal connection part consisting of
x, yy, zz and cc are formed. In this case, the recess cc is a common electrode and is independent of any commutator piece. The winding start terminals of the armature coils 53 and 54 and the air-core armature coil 45 are pre-soldered and hooked on the concave portions xx, yy and zz, respectively, and the winding end terminals are collectively formed by the concave portions cc including the air-core armature coil 45. And is connected by soldering to form a star connection system. Further, although not shown, an electrode pattern for short-circuiting every two commutator pieces is formed on the commutator 66 to constitute the eccentric rotor R2. Here, the structure as a motor is as shown in FIG. That is, the bracket 2 is rotatably mounted on a shaft J fixed to the bracket 7 constituting the housing H together with the casing 2 through a bearing hole 44a of a salient pole 44 made of the nonmagnetic material also serving as a bearing. Electric power is supplied to the armature coils 53 and 54 by bringing a pair of brushes 8 and 8 disposed by soldering 7 through a flexible substrate 7 a into sliding contact with the commutator 66. Here, since the armature coils 53 and 54 and the commutator 66 do not overlap, the commutator 66 can be accommodated within the thickness of the armature coils 53 and 54. The position of the motor is not sacrificed. Other configurations and functions such as the principle of rotation are substantially the same as those in the first embodiment, and therefore, description thereof is omitted. Although the above description has been made of the star connection type, a delta connection can be achieved by changing the position of the brush, the position of the magnetic pole of the field magnet, and the like.

In each of the above embodiments, the commutator has been described as a flat plate type made of a printed wiring board. However, as shown in FIG. 6, a conductor (not shown) for short-circuiting opposing commutator pieces is used. Alternatively, a printed wiring board 67 that is not plated with a noble metal may be integrally formed first, and a thin cylindrical commutator 68 may be soldered and disposed at each terminal 68a. In this case, as the winding start terminal connection portions of the armature coils 53, 54 and the air-core armature coil 45, those corresponding to the concave portions xx, yy, zz, and cc respectively correspond to the printed wiring board 6 not plated with the noble metal.
7 is provided on the outer periphery. At least part of the printed wiring board 67 and the terminal portion (riser portion) 68b of the thin cylindrical commutator 68 are made of the nonmagnetic salient pole 4 in order to pursue thinning.
The brush 88, which is accommodated within the thickness of 4 and is in sliding contact with the thin cylindrical commutator 68, is bent from the middle and implanted in the bracket 7 so as to avoid the projecting portion 55 around which the armature coil is wound. A portion 7a of the support portion 7a of the shaft J fixed to 7 has a part sunk into the cylindrical commutator 68. With this configuration, even a motor having a projecting portion around which an armature coil is wound, which is a feature of the cored motor, can be made thin. Further, instead of each concave portion, each terminal 68a may protrude to the side opposite to the center of gravity. Furthermore, as a modification, a plurality of commutator pieces may be implanted in the non-magnetic salient poles 44 without using the printed wiring board 67 that is not plated with a noble metal. The present invention is not limited to the above embodiments, but various embodiments can be adopted without departing from the spirit of the present invention. For example, a large amount of vibration may be obtained by making the nonmagnetic salient pole a tungsten-containing nylon resin having a specific gravity of 12 or more and increasing the amount of movement of the center of gravity. In this case, a normal sintered oil-impregnated bearing is preferably used for the center bearing hole. In each of the above embodiments, the number of cores is one or two in order to form a flat type. However, it is needless to say that dozens of cores can be stacked and used in an axially long one. The eccentric rotor is not limited to the cored type as long as it is a non-mold type, and may be a type in which an air core coil is mounted on a mold.

[0020]

Since the compact cored vibration motor according to the present invention is constructed as described above, the connection between each terminal of the armature coil and the commutator can be facilitated, the assembling of the commutator can be simplified, and the low-profile eccentric rotor can be provided. That is, a thin vibration motor can be provided, and the following specific effects can be exhibited. According to the first aspect of the present invention, the opposite center of gravity is opposite to the armature coil, so that the terminal can be easily hooked, and since there is sufficient blank space, soldering can be easily performed. According to the second and third aspects of the present invention, even a commutator having a circular outer shape can be reliably engaged. According to the invention described in claim 4,
There is an advantage that the cogging torque is offset and reduced by the two magnetic salient poles facing each other, and the displacement of the center of gravity can be increased by the eccentricity enhancing non-magnetic salient poles. According to the fifth aspect of the present invention, the commutator can be easily assembled without bonding or the like. According to the sixth and seventh aspects of the present invention, the rotor can be made thinner, so that a low-profile motor can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a principal part showing a first embodiment of a small vibration motor having an eccentric rotor of the present invention.

FIG. 2 is a vertical sectional view of the inside of the motor of the embodiment.

FIG. 3 is an explanatory diagram of an operation principle of the embodiment.

FIG. 4 is a main part transverse sectional view showing a second embodiment of the motor of the present invention.

FIG. 5 is a longitudinal sectional view of the inside of the motor according to the second embodiment.

FIG. 6 is a longitudinal sectional view of a main part of a modification of the main part of the present invention.

FIG. 7 is a perspective view of a conventional small vibration motor.

[Explanation of symbols]

 Reference Signs List 1 field magnet 2 casing 3 eccentric core 3a, 33a, 3b, 33b magnetic material salient pole 34 eccentric armature core 4, 44, nonmagnetic material salient pole 51, 52, 53, 54 armature coil 6, 66 flat plate commutator 67 Printed wiring board 68 Cylindrical commutator 7 Bracket 8, 88 Brush J axis H Housing

Claims (7)

[Claims] 1. An eccentric rotor having at least an armature coil portion eccentric and non-molded, and a commutator attached thereto,
In a small-sized vibration motor including a field magnet that applies a magnetic field to the eccentric rotor, a housing that stores the field magnet, a shaft that supports the eccentric rotor, and a brush that slides on the commutator, A small vibration motor having an eccentric rotor which is provided on the side opposite to the center of gravity so as to be able to hook a terminal connection portion of a child coil. 2. A small vibration motor having an eccentric rotor formed by a projection, wherein the means for enabling the engagement is provided. 3. A small vibration motor having an eccentric rotor formed by a recess, wherein the means for enabling the latching is provided. 4. An eccentric rotor comprising two magnetic salient poles eccentrically opposed to each other with an arrangement angle of a blade receiving a magnetic flux of a field magnet, and a magnetic salient pole between the two magnetic salient poles. A nonmagnetic salient pole for eccentricity enhancement made of a high specific gravity slidable synthetic resin having a specific gravity of 5 or more, which is arranged to hold the poles;
4. A small vibration motor comprising the eccentric rotor according to claim 1, comprising an armature coil wound around the magnetic salient poles. 5. A small-sized vibration motor having an eccentric rotor, wherein at least a part of the commutator is integrally formed so as to expose an armature coil terminal connection portion to the nonmagnetic salient pole. 6. A small vibration motor having an eccentric rotor according to claim 4, wherein at least a part of the commutator is accommodated at least within a thickness of the nonmagnetic salient pole. 7. An eccentric rotor configured so that an armature coil wound around the at least two magnetic salient poles and an outer diameter portion of a terminal portion of the commutator do not overlap when viewed from a plane. Small vibration motor.