JP2003062526A - Armature of flat coreless type vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an armature of a flat coreless type vibration motor capable of obtaining a large vibration force even in a miniaturized shape. SOLUTION: In the coreless type armature, a maldistributed coil 12 for generating rotation and made of a plurality of coreless coils is maldistributed and oppositely facing in a fixed magnetic field magnet 2 having a plurality of magnetic poles. The maldistributed coil 12 is arranged in the range of 180 deg. and 240 deg. in the entire periphery 360 deg. of the maldistributed coil 12. A weight 13 made of a non-magnetic body having a high specific gravity is arranged in the range of remaining 180 deg. and 120 deg.. A quality of eccentricity by the weight is made large by setting the position of a center of gravity from the rotation center line of this weight 13 far away from the position of the center of gravity of the maldistributed coil 12.

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, and more particularly to a flat coreless vibration motor armature in which rotation and vibration are generated by unevenly arranged armature coils.

This type of vibration motor is widely used in a device for transmitting a calling signal of a mobile phone or a terminal device as vibration to a human body, a massage device, or the like.

[0003]

2. Description of the Related Art As a coreless vibration motor, an eccentric weight is attached to the rotary shaft of a cylindrical motor, and vibration is generated by this weight, and a plurality of flat coreless coils are provided on the same plane at 180 ° to 240 °. Flat vibration motors that rotate and drive unbalanced rotary vibrations by armatures that are unevenly distributed in the range of ° (Japanese Patent Publication No. 8-1097).
2) is known.

FIG. 4 is a sectional view of a vibration motor 1 using a conventional flat coreless armature. A flat coreless type armature 30 that generates rotation and vibration through the air gap 3 faces the open surface of the annular fixed field magnet 2 having a plurality of magnetic poles. A disc-shaped planar commutator 4 is attached to the center of the armature 30. In addition, the fixed field magnet 2
A brush 5 that is in sliding contact with the commutator 4 is provided therein. The armature 30 is fixed to a shaft 6, and the shaft 6 is rotatably supported by bearings 7, 7. The bearings 7, 7 are provided in the center of the housing 8 and the end bracket 9.

FIG. 5A shows a conventional coreless type armature 30 formed in a fan shape, which is face-to-face with the open surface of the field magnet 2 having four magnetic poles. The armature 30 has an opening angle of 6
Three coreless coils 11 having 0 ° are arranged adjacent to each other on the circumference to form the unevenly distributed coil 12 having an arrangement angle of 180 °. Each coreless coil 11 in this unevenly distributed coil 12
The average opening angle between the effective sides of is 40 °, and the field magnet 2
Is 4 poles, the magnetic pole angle is 90 °, which is short and minimum arrangement.

Such a vibration motor has an uneven distribution coil 12
The vibration is generated by the eccentric amount of only the eccentric coil 12 while being urged to rotate by. However,
When the vibration motor is miniaturized, the amount of eccentricity is reduced, so that there is a problem that the vibration intensity required for practical use cannot be obtained. As a countermeasure against this, as shown in FIG.
The coreless coil at the center is removed from the inside, and a weight 33 having substantially the same size is arranged at the position of this coil. As a result, the amount of eccentricity increases and the amount of vibration can be increased. However, since only two coreless coils 11 are used for rotation, sufficient starting torque cannot be obtained, and there is a problem that the starting becomes unstable. . Further, since the weight 33 also has a small opening angle of 60 °, the amount of eccentricity is inevitably inadequate, so that there is still a problem that the required vibration strength cannot be obtained.

FIG. 6 (a) shows a coreless armature disclosed in Japanese Patent Publication No. 8-10972, in which an armature 40 has three coreless coils 31 having an opening angle of 70 ° on the circumference. The eccentric coils 32 are arranged adjacent to each other and have an arrangement angle of 210 °. The open angle between the effective sides of each coil 31 in the unevenly distributed coil 32 is 50 ° on average, and the field magnet is
When the magnetic poles are poles, the magnetic poles have a short pitch with respect to the angle of 90 °, which is the minimum arrangement.

[0008]

In recent years, mobile phones and terminal equipment have been downsized, and flat coreless vibration motors for call signals stored therein have also been required to be downsized. When the vibration motor is downsized in this way, the eccentricity of the unevenly distributed coil of the armature that generates rotational vibration (the product of the mass of the coil and the center of gravity distance from the center of rotation) decreases, so the vibration force decreases, and The problem arises that signals cannot be transmitted. As a measure against this problem, as shown in FIGS. 5 (b) and 6 (b), the central coreless coil is removed from the unevenly distributed coils, and the weights 33, 43 of which the size is substantially the same as the position of this coil are provided. It has been attempted to increase the amount of eccentricity by arranging.

However, compared to the case of using only the coreless coil, the amount of eccentricity is increased, so that the amount of vibration can be increased, but since the number of coreless coils 11 is reduced to two, sufficient starting torque cannot be obtained. Therefore, there is a problem that the startup becomes unstable. Further, since the open angles of the weights 33 and 43 are as small as 60 ° to 70 °, the amount of eccentricity is inevitably insufficient and the problem that the necessary vibration force cannot be obtained still remains.

In view of the above problems, the present invention is to provide an armature for a flat coreless vibration motor that can obtain a large vibration force even if it is downsized.

[0011]

In order to achieve the above object, an armature of a flat coreless type vibration motor according to claim 1 of the present invention has an open surface of a fixed field magnet having a plurality of magnetic poles. A coreless armature in which an unevenly distributed coil made up of a plurality of coreless coils for generating rotation facing each other is unevenly arranged on a plane orthogonal to a rotation center line, wherein the unevenly distributed coil is included within a 360 ° circumference of the plane. , 180 ° to 240 °
And the remaining 180 ° to 120 °
A weight made of a non-magnetic material having a high specific gravity is arranged in the range of, and the position of the center of gravity from the center line of rotation of the weight is set farther than the position of the center of gravity of the flat coil to increase the amount of concentricity by the weight. Is characterized by.

According to the invention described in claim 1, the remaining 180 ° to 1 in which the coreless type unevenly distributed coil is arranged.
By placing a weight made of a non-magnetic material having a high specific gravity in the range of 20 ° and forming the weight in a substantially disc shape as a whole, the weight having a specific gravity higher than the specific gravity of the unevenly distributed coil allows the center of gravity position from the rotation center line to be determined. The position is farther than the center of gravity due to the unevenly distributed coil, and the amount of eccentricity due to the weight (the product of the mass of the weight and the center of gravity distance from the rotation center) is increased. Further, since the vibration is generated by the eccentric amount of the weight, the necessary starting torque can be obtained without reducing the rotational force of the unevenly distributed coil.

An armature of a flat coreless vibration motor according to a second aspect of the present invention is characterized in that the eccentric amount of the weight is 2.5 to 4 times the eccentric amount of the eccentric coil.

According to the invention described in claim 2, the eccentric amount of the weight is set to be 2.5 to 4 times the eccentric amount of the eccentric coil, and vibration is generated by the eccentric amount of the weight. Further, by appropriately setting the specific gravity and mass of the weight, an arbitrary vibration force can be obtained.

In the armature of the flat coreless vibration motor according to claim 3 of the present invention, the specific gravity of the weight is 11 g / c.
The feature is that it is set to m ^{3 to} 19 g / cm ³ .

According to the invention described in such claims 3, by setting the specific gravity of the weight to 11g / cm ³ to 19 g / cm ^3, and greater than the amount of eccentricity of the ubiquitous coil eccentricity of the weight, weight The vibration is generated by the eccentricity of the. Further, by appropriately setting the specific gravity of the weight, any vibration force can be obtained.

Further, in the armature of the flat coreless type vibration motor according to claim 4 of the present invention, the weight is formed in a substantially fan shape, and the main part is fixedly or rotatably arranged on the shaft, and the uneven distribution coil is arranged. Is fixed by molding so as to be integrated with the weight.

According to the invention described in claim 4, by arranging the main part of the weight fixedly or rotatably with respect to the shaft, the armature is firmly arranged with respect to the shaft and deformed by vibration. And the change over time becomes small, and the life can be extended. Furthermore, by fixing the unevenly distributed coil integrally with the weight by molding, the strength of the armature can be increased.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a vibration motor 1W using the disk-shaped coreless vibration motor armature of the present invention.
The same reference numerals as those in FIG. 4 denote the same parts, and detailed description thereof will be omitted.

End bracket 9 formed in a substantially disc shape
An annular fixed field magnet 2 is provided on the inner surface of the via a suitable spacer. This fixed field magnet 2 is
Four magnetic poles are magnetized alternately in N and S. The end bracket 9 is fitted and fixed to the open end of the housing 8 formed in a substantially dish shape. Bearings 7, 7 are arranged in the central portions of the housing 8 and the end bracket 9 to rotatably support the shaft 6.

A flat coreless type armature 10 according to the present invention is fixed to the shaft 6. As shown in FIG. 2, the armature 10 is composed of an unevenly distributed coil 12 and a weight 13, and faces the open surface of the fixed field magnet 2 with a gap 3 in between. A disc-shaped planar commutator 4 is attached to the center of the armature 10, and a brush 5 arranged in the center of the end bracket 9 is in sliding contact therewith. Alternatively, one end may be fixed to the end bracket 9 or the housing 8 with the shaft 6 as a fixed shaft, and the armature 10 may be rotated with respect to this fixed shaft.

In the unevenly distributed coil 12 shown in FIG. 2, each flat coreless coil 11 has an opening angle of 60 °, and three adjacent coils 11 are circumferentially arranged in a range of 180 °. In the remaining range of 180 °, the non-magnetic weight 13 having a high specific gravity and not affected by the magnetism of the field magnet 13
Are arranged. The weight 13 is formed in a semicircular fan shape, and is fixed to the shaft 6 via a cylindrical bush 14 fitted and fixed to a through hole formed in the main portion 13a. Further, the uneven distribution coil 1 including the three coreless coils 11
2 is integrally molded and fixed to the weight 13. As means for fixing the unevenly distributed coil 12 and the weight 13,
The weight 13 may be integrated by insert molding or outsert molding, or the unevenly distributed coil 12 formed by molding may be fixed to the weight 13 by an appropriate means such as adhesion.

The weight 13 is formed of a non-magnetic metal having a high specific gravity, such as copper or a copper-tungsten alloy,
By setting the specific gravity to 11g / cm ³ to 19g / cm ^3, 2.5 times than the specific gravity of the uneven distribution coil 12 to 4
It is set to double. That is, the specific gravity of the unevenly distributed coil 12 is the specific gravity of copper, which is the wire forming the coreless coil 11, of 8.6.
g / cm ³ and the specific gravity of the resin that molds the coil 11 is about 1 g / cm ³ , so the total is 4.4 g / cm
³ , the specific gravity of the unevenly distributed coil 12 is a universal value, although it varies somewhat depending on the type of resin to be molded.

Based on the specific gravity of the unevenly distributed coil 12, for example,
Specific weight of weight 13 is 8.8g / cm^Three And if the weight
The eccentric amount of 13 becomes twice the eccentric amount of the eccentric coil 12
Vibration is generated by the rotation of the armature 1W. But minutes
The specific gravity of the unevenly distributed coil 12 is offset from the specific gravity of the copper 13.
Therefore, substantially only the conventional unevenly distributed coil 12 vibrates.
Become the same as power. Therefore, in the above-mentioned conventional vibration motor
In order to generate a larger vibration force than
Set the specific gravity of the weight 13 to be more than twice the specific gravity of the unevenly distributed coil 12.
Must be set, and practically set to 2.5 times or more.
Will be required.

Incidentally, if the specific gravity of the weight 13 is set to 2.5 times, that is, 11 g / cm ³ , the specific gravity of the unevenly distributed coil 12 is canceled out, and an unbalanced eccentricity of 1.5 times is obtained. Further, when the specific gravity of the weight 13 is set to be tripled to 13.2 g / cm ³ , the specific gravity of the unevenly distributed coil 12 is offset, and a double unbalanced eccentric amount is obtained. Furthermore, set the specific gravity of the weight 13 to 4
When doubled to 17.6 g / cm ³ , similarly, an unbalanced eccentricity of 3 times is obtained, and the vibration force is increased by increasing this magnification. The copper-tungsten alloy described above has a maximum specific gravity of 18.77 g / cm ³ , and if the specific gravity of the unevenly distributed coil 12 is offset, an unbalanced eccentricity of 3.3 times is obtained.

The relationship between the eccentric amount of the unevenly distributed coil 12 and the weight 13 and the specific gravity in the armature 1W shown in FIG. 2 described above will be mechanically outlined. In the case of a 360 ° disc having a uniform specific gravity and thickness, , 2 at A and B at any central angle
When divided, the amount of eccentricity of A (the product of the mass and the center of gravity from the center) and the amount of eccentricity of B are equally balanced, and rotational vibration due to imbalance does not occur. However, when there is a difference between the specific gravity of A and the specific gravity of B, a difference occurs between the eccentricity amount of A and the eccentricity amount of B, the balance is lost, and rotational vibration due to unbalance occurs. That is, the rotational vibration occurs only by the difference in specific gravity. In the armature 1W shown in FIG. 2, A is divided into 180 ° and B is divided into 180 ° so that the specific gravity of the weight 13 is made larger than that of the unevenly distributed coil 12, so that the eccentricity is increased. And the balance is lost, and rotational vibration due to this imbalance can be generated.

FIG. 3 shows another embodiment of the flat coreless armature according to the present invention. The armature 20 includes an unevenly distributed coil 21 and a weight 23, and faces the open surface of the fixed field magnet 2 with a gap 3 in between.

In the unevenly distributed coil 22 shown in FIG. 3, each flat coreless coil 21 has an opening angle of 80 °, and three adjacent coils 21 are circumferentially arranged in a range of 240 °. In the remaining range of 120 °, the non-magnetic weight 23 having a high specific gravity and not affected by the magnetism of the field magnet.
Are arranged. The weight 23 is formed in a fan shape, and is fixed to the shaft 6 through a cylindrical bush 14 that is fitted and fixed in a through hole formed in the main portion 23a. Furthermore, 3
The unevenly distributed coil 22 including the individual coils 21 is integrally molded and fixed to the weight 23. Uneven distribution coil 22
Similarly to the above-described example, the fixing means of the weight 23 and the weight 23 is integrated with the weight 23 by insert molding or outsert molding, or the molded unevenly distributed coil 22 is fixed to the weight 23 by an appropriate means such as bonding. You may do it.

The coreless armature 2 having the above structure
In 0, the arrangement open angle of the coil 21 is 80 °, and the average open angle of the two effective sides that contribute to the rotational force in each coreless coil 21 is 60 °. The field magnet 2 facing the armature 20 is magnetized to have 6 poles, and the opening angle of each magnetic pole is 60 degrees.
Since the total number of rotations is for .degree., The winding amount and the flux can be made larger than those of the short-pitch coil 11 shown in FIG. 2 described above, so that the rotational biasing force can be increased.

The eccentricity amount of the unevenly distributed coil 22 in the armature 20 is 0.27R when the radius of the armature 20 is R and the center of gravity from the center of rotation. This is because the distance of the center of gravity of the eccentric coil 12 shown in FIG. 2 is smaller than 0.42R, the eccentric amount of only the eccentric coil 22 is reduced, and the necessary vibration force is required when the vibration motor itself is downsized. I can't get it. On the other hand, the distance of the center of gravity of the weight 23 having an angle of 120 ° is 0.55R, and the amount of eccentricity increases, so that strong vibration can be generated. In the case of the armature 20 shown in FIG. 3, the specific gravity of the weight needs to be at least 11 g / cm ³ , and further downsizing requires about 19 g / cm ³ .

The present invention described above does not generate rotational vibration due to the amount of eccentricity due to the uneven distribution coil as in the coreless type flat vibration motor shown in FIG. 4 to FIG. 180 ° to 120 °
In this range, a weight made of a non-magnetic material having a high specific gravity is placed, and the eccentric amount of this weight causes rotational vibration. Therefore, there is a feature that an arbitrary vibration force can be obtained by appropriately setting the specific gravity and mass of the weight. In particular, even when the mass of the unevenly distributed coil is reduced due to downsizing of the vibration motor, a large vibration force can be easily obtained by disposing an appropriate weight. Furthermore, since the source of rotational vibration is a weight without involving the unevenly distributed coil,
The necessary starting force can be obtained without reducing the rotational biasing force required for the motor. Also, the main part of the weight is fixedly or rotatably arranged on the shaft, and by fixing the unevenly distributed coil to this weight, the fixing strength is greatly improved, which makes it possible to extend the service life and improve reliability. improves.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the present invention. For example, three coreless coils are arranged adjacent to each other on the circumference to form an eccentrically distributed coil. However, coreless coils having a large opening angle are made to overlap each other in consideration of the number of poles of the field magnet. Good. Also,
In relation to the number of phases, the number of unevenly distributed coils may be changed to two or four.

[0033]

As described above, in the armature of the flat coreless type vibration motor according to the present invention, a weight made of a non-magnetic material having a high specific gravity is provided in the remaining range of 180 ° to 120 ° in which the unevenly distributed coils are arranged. Since they are arranged and rotational vibration is generated by the amount of eccentricity caused by this weight, an arbitrarily large vibration force can be easily generated even if the vibration motor is downsized. Further, since the source of the rotational vibration is the weight, the rotational biasing force and the starting force required for the motor can be obtained without being involved in the uneven distribution coil. Further, if the weight is fixedly or rotatably supported on the shaft and the unevenly distributed coil is fixed to the weight, the fixing strength is greatly improved, and the life and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a flat coreless vibration motor according to the present invention.

FIG. 2 is a plan view showing an armature of the flat coreless vibration motor according to the present invention.

FIG. 3 is a plan view showing another embodiment of the armature of the flat coreless vibration motor according to the present invention.

FIG. 4 is a sectional view showing a conventional flat coreless vibration motor.

5A and 5B are plan views showing an armature of a conventional flat coreless vibration motor.

6A and 6B are plan views showing another armature in the conventional flat coreless vibration motor.

[Explanation of symbols]

1W vibration motor 2 times magnet 3 void 4 commutator 5 brushes 6 axes 7 bearings 8 housing 9 End bracket 10 armature 11 coils 12 unevenly distributed coils 13 weights 20 armature

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 23/54 H02K 23/54 23/58 23/58 Z F term (reference) 5D107 AA02 AA13 BB07 BB08 CC08 DD09 5H603 AA00 BB01 BB14 CA02 CA05 CC14 CC19 CD13 CE01 5H604 AA08 BB01 BB11 BB12 BB13 CC02 CC04 CC12 5H607 AA00 BB01 BB13 CC01 CC03 DD01 DD02 DD03 DD16 EE58 KK10 5H623 AA00 BB06 GG12 H06 H10 GG16H1009

Claims (4)

[Claims] 1. A coreless electric machine in which an eccentrically-distributed coil, which is composed of a bifurcated coreless coil for rotation generation and which faces an open surface of a fixed field magnet having a plurality of magnetic poles, is eccentrically arranged on a plane orthogonal to a rotation center line. The child is a child, and the eccentric coil is 180 ° to 240 ° out of 360 ° of the entire circumference of the plane.
In the flat coreless vibration motor, the center of gravity from the center of rotation of the remaining 18 rotations is set farther than the center of gravity of the flat coil to increase the amount of eccentricity due to the weight. Armature. 2. The armature for a flat coreless vibration motor according to claim 1, wherein the eccentric amount of the weight is 2.5 to 4 times the eccentric amount of the eccentric coil. 3. The specific gravity of the weight is 11 g / cm ^{3 to} 19
The armature for a flat coreless vibration motor according to claim 1, wherein the armature is set to g / cm ³ . 4. The weight according to claim 1, wherein the weight is formed into a substantially fan shape, the main part is fixed or rotatably arranged on the shaft, and the unevenly distributed coil is fixed by molding so as to be integrated with the upper partial copper. Flat coreless vibration motor armature.