JP3512853B2 - Vibration motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration motor, and more particularly to a vibration motor which is suitable for use in a pager or the like and which converts its own rotational movement into vibration.

BACKGROUND OF THE INVENTION In recent years, with the development of communication, pagers which send a message to a target party using radio waves transmitted from a wireless station have been rapidly spread.

This pager is a mobile communication system that informs the other party that a call signal or a message has been received by sending a tone signal or simple data by radio, and is typical. There are a call notification dedicated type and a message display type, and various types such as a pocket type, a card type, and a wristwatch type.

In addition, when a pager receives a message, it has been customary to inform the user that a message has been addressed to him by a ringing sound of an alarm or the like. In recent years, many devices have been provided, which assume the situation and notify the reception by vibration instead of sound.

Generally, when a vibrating force is required, it is considered that the vibration is obtained by reciprocating motion and the vibration is obtained by rotating motion. In the case of vibration by the reciprocating motion of the moving body, the inertia of the moving body is killed. It is necessary to invert repeatedly and it is inefficient.

On the other hand, in the case of vibration utilizing the rotational movement of the motor or the like, inertia is effectively utilized because the eccentric weight is always rotated in the forward direction of rotation.
At the same time, the frequency of vibration is determined by the number of revolutions, so it can be set within a range that does not cause noise, so under the condition that the number of revolutions of the weight does not resonate with the motor body, vibration of large displacement at low frequency It is relatively easy to obtain.

From this, the vibrating pager, in which the vibrating body is housed in the receiver case and vibrates based on the calling signal, is provided with the eccentric weight on the motor shaft, and the eccentric weight generated by the rotation of the motor shaft is eliminated. A configuration that utilizes vibration due to whirling force is common.

Then, the following requirements are required for the vibration motor used in the pager for performing the reception notification by the vibration as described above. Small rated current (power saving) 1. 2. Low self-starting voltage (small static friction coefficient of sliding part, large starting torque, small cogging torque). 3. Make sure to start at low voltage below comma (commutator and brush contact parts are highly reliable members). 4. Low noise (low rotation speed, no bearing noise due to parasitic torque unevenness, and no resonance with motor support). 5. Large swinging force (large eccentric weight and eccentric weight radius, and high rotation speed) 6. Be thin (at least have thin dimensions,
6. The small diameter of the rotating part and the high flexibility of mounting on the support without exposing the rotating part. Low cost (do not use expensive materials such as field magnets and eccentric weights).

A careful examination of the above requirements reveals that there are some contradictory requirements.

For example, if an expensive rare earth magnet is used as the field magnet in order to reduce the thickness (small size) and keep the rated current low, the above requirements 1 and 6 can be satisfied, but the above requirement 7 is satisfied. In addition, if the clearance between the shaft and the bearing is made small in order to prevent noise due to rattling of the metal bearing, the minimum self-starting voltage rises, and the above requirement 2 can not be satisfied although the requirement 4 can be satisfied.

Therefore, the vibration motor is required to be constructed while satisfying the above requirements 1 to 7 in a well-balanced manner.

[0012]

2. Description of the Related Art Conventionally, a vibration motor having an eccentric weight as described above is the most general as a vibration motor used in a pager for making a reception notification by vibration.
[Fig. 4] is a perspective view showing an example of the external appearance of a vibration motor of this conventional structure.

FIG. 4 is a time vector diagram showing the whirling force due to the generated vibration in the vibration motor having the above-mentioned conventional structure.

In FIG. 3, a vibration motor 101 is composed of a motor case 102, a shaft 103, and an eccentric weight 104. The motor body is generally of a small diameter cylindrical type for the purpose of eliminating cogging torque, or The small-diameter thin coreless motor shown in FIG. 3 is used.

Further, the coreless vibration motor 10
1 As the field magnet used inside, for example,
Samarium cobalt (Sm-Co) system and neodymium iron (Nd-F)
e) Rare earth magnets such as type are mainly used.

The shaft 103 is a rotary shaft of a motor main body rotor portion of the vibration motor 101, and an eccentric weight 104 having a substantially fan-shaped cross section and having tungsten as a main component is provided at a tip portion of the shaft 103.

In other words, the above-mentioned constitutions are contradictory requirements that a pager is required to obtain a large whirling force with a thin shape (diameter of a rotating portion) and a large whirling force with low noise (rotational speed). Has been empirically selected to achieve a well-balanced fill within a limited size.

By the way, since the vibration motor 101 originally needs only to rotate the eccentric weight 104, a low starting torque should be sufficient, but a high starting torque is required due to the demand for low voltage self-starting. From this point as well, there is a merit in using the rare earth magnet.

In the above structure, as shown in FIGS. 3 and 4, the vibration motor 101 moves in the direction of the white arrow A in FIG. 3 with reference to the XX 'axis and the YY' axis. When rotated, the time locus of the whirling force of the eccentric weight 104 based on the rotation of the vibration motor 101 becomes a locus as shown in FIG.
As a result, when the vibration motor 101 is mounted on the vibration support (pager main body), the vibration support mainly includes X-
An oscillating force is generated on the YY 'axis plane that is orthogonal to the X'axis, and as shown by the one-dot chain line in FIG. 4 (b), XX'
It vibrates in the direction intersecting the YY 'axis direction with respect to the axis plane, and at the same time, as shown by the chain double-dashed line in FIG. Vibrates in the direction.

As a result, the vibration motor vibrates in the pager body based on the calling signal, and the pager holder is sensationally notified of the incoming call signal.

[0021]

However, in such a conventional vibration motor, due to the demand for miniaturization,
Since the rare earth magnet is used as the field magnet and the eccentric weight 104 containing tungsten as a main component with high specific gravity is used to increase the whirling force, there are problems as described below.

That is, as shown in FIG.
The motor case 102 of 101 is required to have a small diameter and a thin shape.
As shown in, the vibration motor 10 is made thinner along the thin width side.
It is necessary to mount and support 1 or to make it a cylindrical type with an extremely small diameter, but in the past, even if the cost increased, a large magnetic density with a small volume is required to reduce the size of the motor. It was determined that the advantage of using the obtained field magnet was greater, and expensive rare earth magnets such as samarium cobalt were used, and there was always the problem that cost reduction could not be achieved.

Further, in order to increase the whirling force, the eccentric weight 104 having a high specific gravity is used. Generally, the whirling force is the specific gravity, the cube of the radius and the length of the eccentric weight 104, and the fan shape in FIG. The angle θ is proportional to sin θ / 2 and the square of the rotation speed.

That is, in the example shown in FIG. 3, the eccentric weight 10
The radius of 4 must be set within the dimension of the width t, and the radius dimension is naturally limited, but in the past, in order to increase the whirling force even if the cost increases, a metal with a large specific gravity is required. Judging that the advantage of using the eccentric weight 104 using is greater, the eccentric weight 104 whose material is expensive tungsten as the main component is used, and like the field magnet described above, cost reduction is possible. There was a problem that it was not planned.

Therefore, in order to obtain the high-performance vibration motor 101, conventionally, expensive materials are used for the field magnet and the eccentric weight 104, so that there is a problem that the cost becomes high.

[Purpose] In view of the above problems, an object of the present invention is to provide a vibration motor that is low in cost and has a large whirling force.

[0027]

The invention described in claim 1 is, as shown in FIG. 1, a core 2a, 2b having at least two sets of tooth tips, and for each tooth tip of the cores 2a, 2b. A plurality of sets of winding phases 3a to 3c that are distributed and wound, and the winding phases 3a
The commutator 4 for commonly connecting the windings in 3c to 3c is provided on the same shaft 5, and the rotating armatures whose center of gravity is deviated are arranged to face each other in a common field pole. There is.

In this case, in addition to the invention described in claim 1, as described in claim 2, the torque generating position generated by a plurality of sets of winding phases wound around each tooth tip of the core is set. Biasing is effective.

In addition to the invention described in claim 1 or 2, as described in claim 3, the core is composed of an iron core, and the field pole is composed of a ferrite magnet. It is preferable to vibrate based on the eccentric rotational couple generated by the dispersion of the wire phase, and the constant torque couple and the vibration torque couple due to the electrical mounting of the winding phase.

[0030]

According to the invention described in claim 1, since a plurality of sets of winding phases are dispersedly wound around each tooth tip of the core,
Since the position of the center of gravity of the rotating armatures provided on the same shaft is biased, a whirling force is generated by itself with the rotational movement of the motor.

As a result, the desired vibration can be obtained without using an expensive eccentric weight, so that the cost can be reduced, and since the rotating part is not exposed, the degree of freedom in the arrangement of parts is increased, and the mounting place and design Can be widened.

In this case, according to the invention of claim 2,
Since the torque generation position generated by the multiple winding phases wound around each tooth tip of the core is biased, there is a constant torque couple in the motor due to the rotational motion of the motor and a vibration couple due to the switching of the current. Occurs.

As a result, like the above-mentioned invention of claim 1, the cost can be reduced, the degree of freedom in arranging the parts can be increased, and the design can be widened more effectively. Be done.

In this case, according to the third aspect of the invention, since the iron core is used as the core, the gap (hereinafter referred to as the air gap) can be set small. Since inexpensive materials such as magnets can be used, the above-mentioned claim 1 or 2 can be used.
In addition to the described invention, further cost reduction can be achieved.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to. 1 and 2, the same parts are designated by the same reference numerals.

First, the configuration of this embodiment will be described.

FIG. 1 is a schematic configuration diagram of the vibration motor of this embodiment, and FIG. 2 is a cross-sectional view of essential parts of the vibration motor of this embodiment.

In FIGS. 1 and 2, the vibration motor 1 comprises iron cores 2a and 2b as cores, winding phases 3a to 3c, a commutator 4, a shaft 5, a brush 6, and a field magnet (permanent magnet) 7. Has been done. Reference numeral 8 in FIG. 1 is a power supply terminal.

The iron cores 2a and 2b are winding cores each having three tooth tips in 120 ° units so that three winding phases can be formed, and by the shaft 5, as shown in FIG.
The iron cores 2a and 2b are arranged so that the tooth positions thereof face each other. By the way, the spacing between tooth tips, that is, the magnetization distribution is formed to be substantially the same as the tooth width in consideration of cogging torque.

The winding phases 3a to 3c are formed by winding the windings on the iron cores 2a and 2b. In this embodiment, as shown in FIG. Core 2b which forms winding phase 3a and winding phase 3b at the corresponding positions of and which faces the tooth tip where the winding phase is not formed in iron core 2a.
The winding phase 3c is formed at the corresponding position of the tooth tip of the. The winding in this embodiment is a so-called Y-shaped connection in which the winding start side of the winding phases 3a to 3c is brought into contact with each piece of the commutator 4 and the winding end side is connected together. There is.

That is, by winding the winding phases 3a, 3b and the winding phase 3c in a distributed manner on the iron cores 2a, 2b, the center of gravity position and the torque of the iron core 2a side and the iron core 2b side can be arranged on the same shaft 5. A rotating armature is formed in which the generation positions are biased.

The commutator 4 causes the power supply current supplied from the brush 6 to flow through the winding phases 3a to 3c at a predetermined timing, and in order to supply the power supply current from the fixed object to the rotating body,
Electric current is supplied using the sliding surface.

The shaft 5 is the rotation axis of the vibration motor 1, that is, the rotation center axis of the rotary armature.

The brush 6 supplies the power supply current supplied from the power supply terminal 8, and specifically, the commutator 4
An electric current is supplied through the sliding surface of the.

The field magnet 7 is composed of a pair of N-pole and S-pole ferrite magnets having a substantially arcuate ")" shape in cross section, and as shown in FIG. 2, it is as small as possible between the iron cores 2a and 2b. It is installed in the motor case through the set air gap.

Next, the operation (action) of this embodiment will be described.

As described above, on the same shaft 5, the winding phases 3a and 3b and the winding phase 3c are distributed and wound around the iron cores 2a and 2b, so that the iron core 2a side and the iron core 2b side are A rotary armature is formed in which the center of gravity position and the torque generation position are biased.

That is, when the power supply current is supplied from the power supply terminal 8, the current flows through the brush 6 to the winding phases 3a to 3c at a predetermined timing, and the rotary armature of the vibration motor 1 starts to rotate. .

The vibrational force associated with the rotation of the rotating armature is expressed as a couple of the torque generated by the eccentricity in the winding phases 3a and 3b and the winding phase 3c and the centrifugal synthetic force, and is indicated by a white arrow B in FIG.
It occurs in the direction indicated by B '.

This replaces the conventional eccentric weight,
A whirling force is generated in the vibration motor 1 by a couple moment due to the axially separated and distributed arrangement of the windings, and vibration is obtained.

Further, since the vibration motor 1 of this embodiment is not a coreless motor which has been widely used in the related art, the air gap between the field magnet 7 and the iron cores 2a, 2b is made as small as possible, so that Since the magnetic force can be effectively used, a sufficient magnetic force can be obtained even if a ferrite magnet is used as in this embodiment.

In addition to the above-described vibration couple, a constant torque couple and a torque uneven vibration couple are generated when the current is switched by the commutator 4.

As described above, in this embodiment, the field magnet 7 and the iron core 2 are compared with the conventional coreless motor.
By setting the air gap between a and 2b as small as possible, an inexpensive ferrite magnet can be used as the magnetic material used for the magnet, and the cost can be reduced.

Further, a plurality of sets of winding phases 3a to 3c are dispersedly wound around the tooth tops of the iron cores 2a and 2b to form the same shaft 5
By biasing the center of gravity of the rotating armature provided above, the whirling force can be generated by the motor alone, and as a result, the eccentric weight can be saved and the rotor portion that generates the whirling force is generated. Can all be built into the motor case.

Therefore, the desired vibration can be obtained without using an expensive eccentric weight, so that the cost can be reduced.

Further, since the rotating portion is not exposed structurally, the degree of freedom in arranging components can be increased, and the mounting place and design, and the width of the design can be widened.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the winding phases 3a to 3c.
Although the connection structure of 1 is described as a Y connection, it may be a Δ (delta) connection or a multipolar structure.

In this embodiment, a ferrite magnet is used as the field magnet in order to reduce the cost. However, by using a rare earth magnet such as samarium cobalt magnet or neodymium iron magnet, it is possible to reduce the size. The magnet material may be variously changed according to its purpose, that is, cost reduction and miniaturization / low power consumption.

In the above description, the invention mainly made by the inventor is applied to a vibration motor for a pager, which is a field of application which is the background of the invention. However, the invention is not limited to this. It can also be applied to vibration generators for massagers.

[0061]

According to the first aspect of the present invention, a plurality of sets of winding phases are distributed and wound around each tooth tip of the core, so that the center of gravity of the rotating armature provided on the same shaft is located. Can be biased, and the whirling force can be sufficiently generated by the motor alone in accordance with the rotational movement of the motor.

Therefore, the desired vibration can be obtained without using an expensive eccentric weight, the cost can be reduced, and the rotational portion is not exposed due to the structure, so that the degree of freedom in arranging the parts can be increased. It is possible to expand the range of design.

Further, according to the second aspect of the invention, the torque generating position generated by the plurality of sets of winding phases wound around each tooth tip of the core can be biased, so that the winding occurs as the motor rotates. A vibrating force can be effectively taken out by applying a bias to the whirling caused by the eccentric center of gravity of the line.

As a result, similarly to the above-mentioned invention of claim 1, the vibration due to the whirling force is functionally sufficient, the cost can be reduced, and the degree of freedom in arranging the parts can be increased to improve the design. The effect that the width can be widened can be more effectively taken out.

Further, in this case, according to the third aspect of the invention, the air gap can be set small by using the iron core as the core. Therefore, for the field pole, for example, an inexpensive material such as a ferrite magnet is used. In addition to the invention according to claim 1 or 2 described above,
Further cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a vibration motor according to an embodiment.

FIG. 2 is a cross-sectional view of a main part of the vibration motor according to this embodiment.

FIG. 3 is a perspective view showing an appearance of a conventional vibration motor.

FIG. 4 is a time vector diagram showing a whirling force due to vibration of a conventional vibration motor.

[Explanation of symbols]

1 Vibration motor 2a, 2b Iron core 3a-3c winding phase 4 commutator 5 shafts 6 brushes 7 Field magnet 8 power supply terminals 101 vibration motor 102 motor case 103 shaft 104 Eccentric weight

Claims (3)

(57) [Claims] 1. A core having at least two sets of tooth tips, a plurality of sets of winding phases dispersedly wound around each tooth tip of the core, and respective windings in the winding phases are commonly connected. A vibration motor, characterized in that a commutator and a commutator are provided on the same shaft, and rotating armatures whose center of gravity is biased are arranged to face each other in a common field pole. 2. The vibration motor according to claim 1, wherein torque generation positions caused by a plurality of winding phases wound around each tooth tip of the core are biased. 3. The core is composed of an iron core, and the field poles are composed of a ferrite magnet. The eccentric rotational couple generated by the dispersion of the winding phases and the constant mounting by electrical mounting of the winding phases. The vibration motor according to claim 1, wherein the vibration motor vibrates based on the torque couple and the vibration torque couple.