JPH09149592A - Cylindrical microbivration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix an eccentric weight to a rotary shaft firmly enough even with only the pressing force such as additional fastening, etc., without enlisting the aid of an adhesive as in the past, even in the base that the eccentric weight which can generate large vibration force is attached in an ultrathin cylindrical microvibration motor. SOLUTION: For this motor, a rotary shaft mounting groove 7-1 where a rotary shaft 2 can be inserted from the opposite direction to the direction of center of gravity is made at the rotary shaft mounting base 3b made at the face part on opposite side to the direction of center of gravity of an eccentric weight 3-1, and the inner face of this rotary shaft mounting groove 7-1 is constituted in polygonal face which contacts at four or five places with the periphery of the above rotary shaft 2d. The above eccentric weight 3-1 is attached to the rotary shaft 2 by pressing the ends of both openings of the mounting groove 7-1 to the periphery of the above rotary shaft 2 with a means for additional fastening or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical micro-vibration motor which is adapted to obtain a vibration by a centrifugal force by rotating an eccentric weight attached to a rotary shaft of a cylindrical micro-motor, for example, in a wireless communication device. Used for calling devices (pagers).

[0002]

2. Description of the Related Art A cylindrical micro-vibration motor is used as a vibration generator for causing a pager to call the pager by vibration in addition to sound. In this cylindrical micro-vibration motor, as shown in FIG. 6, an eccentric weight 3'made of a high specific polymerization heavy metal such as a tungsten alloy is attached to a rotary shaft 2 of the cylindrical micro motor 1, and the eccentric weight 3'is attached to the rotary shaft 2. By rotating together with it, vibration is obtained by the centrifugal force of the eccentric weight 3 '.

Here, there are various methods for attaching the eccentric weight 3 'to the rotating shaft 2, and a typical method is disclosed in Japanese Utility Model Publication No. 4-13860. This will be described with reference to FIG. 6. After inserting the rotary shaft 2 of the cylindrical micromotor 1 into the shaft hole 4 of the eccentric weight 3 ′, a direction opposite to the center of gravity of the weight portion 3 ′ a of the eccentric weight 3 is inserted. The eccentric weight 3'is attached to the rotary shaft 2 by crimping with a tool such as a punch (not shown) on the surface of the rotary shaft attachment base 3'b at the position shown by the crimp portion 5.

Although the method shown in FIG. 6 is a method of attaching the eccentric weight 3'to the rotary shaft 2 which is very excellent in mass productivity, only one place is added to the peripheral surface of the rotary shaft 2. Untightened 1-point caulking (contact with the rotating shaft 2 at 2 points)
Therefore, the attachment strength of the eccentric weight 3 ′ to the rotary shaft 2 is poor, and when the eccentric weight 3 ′ is rotated at a high speed, the eccentric weight 3 ′ may fall off the rotary shaft 2.

According to the method for attaching the eccentric weight 3'to the rotary shaft 2, the outer diameter size is generally limited to Φ6 mm or more, and the outer diameter size is smaller, for example, Φ.
In the case of a size of 4 mm or less, there is a limit in trying to obtain a larger vibration, and a sufficiently large vibration cannot be obtained.

This is because the eccentric weight has a smaller outer diameter, the weight of the eccentric weight is reduced, and the torque of the motor is deteriorated as the cylindrical microvibration motor having an extremely fine shape is used. To prevent this deterioration,
It can be prevented to some extent by rotating the motor at a high speed. However, what is more fatal than anything else is that the volume of the rotary shaft attachment base 3′b becomes large, and therefore the center of gravity that causes the magnitude of vibration of the eccentric weight 3 ′ by the volume of the rotary shaft attachment base 3′b. The volume and weight of the weight portion 3'a in the directions are canceled out, and as a result, the generated vibration force is reduced. Therefore, with the method of attaching the eccentric weight 3'to the rotary shaft 2 shown in FIG. 6, it is difficult to obtain an ultrafine cylindrical microvibration motor that generates a large vibration force.

As a method for solving the above-mentioned drawbacks, as shown in JP-A-6-30544 and JP-A-6-98496, for example, as shown in FIG. The weight is reduced by reducing the volume of the attachment base portion 3 "b, and the attachment base portion 3" b is less likely to cancel the volume and weight of the weight portion 3 "a to reduce the weight portion 3 '. There is a method to obtain large vibration by'a. Even a slight reduction in the volume and weight of the rotating shaft mounting base 3 ″ b does not significantly affect the magnitude of the vibration force generated by the micro-vibration motor having an extremely fine cylindrical shape such as Φ3 to Φ4. The same motor can be judged very easily by replacing the eccentric weight 3 '' and trying.

The eccentric weight 3 ″ as shown in FIG. 7 and the above-mentioned known example for fixing the eccentric weight 3 ″ to the rotating shaft 2 will be further described with reference to FIGS. 8 and 9.

In both of the eccentric weights 3 "shown in FIGS. 8 and 9, the center of gravity 6 is attached to the rotary shaft mounting base 3" b formed on the surface of the eccentric weight 3 "opposite to the direction of the center of gravity 6". Recessed rotary shaft attachment grooves 7'and 7 '' are formed so that the rotary shaft 2 can be inserted from the direction opposite to the direction.

In the case of the eccentric weight 3 '' shown in FIG. 8, the rotary shaft mounting groove 7'is formed on a surface having a U-shaped inner surface portion 9 which is in contact with the inner surface of the rotary shaft 2 at a semicircular portion or more. Then, the outer circumference of the rotary shaft 2 is brought into semi-circular contact, and the rotary shaft 2 is inserted into the attachment groove 7 ′ from the side surface in the direction opposite to the center of gravity 6, and then both opening side surface end pieces 8 ′ of the groove 7 ′ are inserted. By pressing on the peripheral surface of the rotary shaft 2 by means such as caulking, the eccentric weight 3 ″ is brought into contact with the outer periphery of the rotary shaft 2 almost entirely.
Attached to.

In the case of the eccentric weight 3 ″ shown in FIG. 9, the rotary shaft mounting groove 7 ″ has a rectangular groove shape toward the side surface, and the rotary shaft 2 has a center of gravity in the mounting groove 7 ″. When the rotary shaft 2 is inserted from the side surface opposite to 6, the inner surface of the attachment groove 7 ″ and the outer peripheral surface of the rotary shaft 2 are brought into contact with each other at three points. The eccentric weights 3 ″ are attached to the rotary shaft 2 by pressing both opening side surface end pieces 8 ′ against the peripheral surface of the rotary shaft 2 by means such as caulking.

[0012]

As described above, the method of attaching the eccentric weight 3'to the rotary shaft 2 shown in FIG. 6 is the simplest for a cylindrical micro vibration motor having a relatively large outer diameter. This is a very useful method, but since the volume and weight of the attachment base 3'b on the opposite side of the center of gravity 6 becomes large, it is not possible to maximize the eccentric vibration amount of the eccentric weight 3 '. Small size, eg Φ4m
Not suitable for m size cylindrical micro vibration motor.

On the other hand, in the method of attaching the eccentric weight 3 '' to the rotary shaft 2 shown in FIGS. 7 to 9, the volume and weight of the attachment base 3''b on the opposite side of the center of gravity 6 are large. Therefore, the amount of eccentric vibration of the eccentric weight 3 ″ is maximized, which is suitable for a cylindrical micro vibration motor having a small diameter size, for example, Φ4 mm size.

However, some problems still occur in the method of attaching the eccentric weight 3 ″ to the rotary shaft 2 shown in FIGS. 7 to 9, and many problems remain to be solved.

That is, in the method of attaching the eccentric weight 3 ″ shown in FIG. 8 to the rotating shaft (which has a smaller outer diameter size than that in the case of FIG. 6) 2, the ultra-fine cylindrical shape is used. It needs to be rotated at a high speed because a small torque is generated like a micro-vibration motor. When rotating at such a high speed, the rotary shaft 2 is greatly moved toward the center of gravity 6, but the rotary shaft mounting groove 7 ' The inner peripheral surface and the outer peripheral surface of the rotary shaft 2 are in contact with each other over most of the area (substantially full surface contact type). Although the force that elastically receives the rotary shaft 2 and holds the rotary shaft 2 in that position is small, this method has an advantage, but as a result, just like the method shown in FIG. This is the same as the one-point crimping method in which the mounting base portion 3 ″ b is crimped to the rotary shaft 2 after the rotary shaft 2 is inserted.

When the motor is rotated at a high speed because a small torque is generated like a cylindrical micro vibration motor having an ultrafine shape, the rotating shaft 2 having an outer diameter size smaller than that in the case of FIG. , A large gap is formed between the rotary shaft 2 and the inner peripheral surface of the rotary shaft mounting groove 7 ', and the rotary shaft 2 falls off the rotary shaft mounting groove 7', or in the opposite case, the rotary shaft 2 Various troubles occur due to the contact between the two. Therefore, by further using an adhesive, the rotary shaft 2 and the rotary shaft attaching groove 7 '
It is necessary to take reinforcement measures such as bonding between them, which is very expensive.

The eccentric weight 3 '' of FIG. 8 described above
In the method shown in FIG. 9, which is a result of improving the method of attaching the rotary shaft to the rotary shaft (having a smaller outer diameter size than that in FIG. 6), On the rotating shaft 2
When the is inserted, the outer circumference of the rotary shaft 2 and the rotary shaft mounting groove 7 ''
The inner surface of is in contact at three points. Here, even if the opening side surface end piece 8 ′ is swaged to the rotary shaft 2 side, as a result, the outer circumference of the rotary shaft 2 and the inner circumference of the rotary shaft attachment groove 7 ″ are at three points. Only contacted.

The caulking means of the eccentric weight 3 '' of FIG. 9 in which the outer circumference of the rotary shaft 2 and the inner circumference of the rotary shaft mounting groove 7 '' are in contact with each other at three points is very high. Although useful, only the inner surface of the rotary shaft mounting groove 7 ″ in the direction of the center of gravity 6 and the inner surface of the rotary shaft mounting groove 7 ″ in the direction perpendicular to the direction of the center of gravity 6 are in contact with the rotary shaft 2. In the ultra-fine cylindrical micro vibration motor that must rotate at high speed, the center of gravity 6
Since a large load is applied to the direction, it is desirable to firmly receive the force applied by the rotary shaft 2 in the direction of the center of gravity 6 at the rotary shaft attachment groove 7 ″ at an angle position different from the direction of the center of gravity 6.

In this respect, according to the method of attaching the eccentric weight 3 ″ according to FIG. 9 to the rotary shaft (which has a smaller outer diameter size than that of FIG. 6) 2, the rotary shaft 2 is attached to the center of gravity 6.
Since it has a three-point contact structure that receives the rotary shaft 2 on both sides of the rotary shaft attachment groove 7 ″ which is perpendicular to the above, the load on the center of gravity 6 of the rotary shaft 2 is absorbed as compared with the method of FIG. it can.

However, according to the method of attaching the eccentric weight 3 '' to the rotary shaft 2 according to FIG. 9, the opening side surface end piece 8'is pressed toward the rotary shaft 2 by means such as caulking as shown by a dotted line. However, since there is no surface that directly receives the pressing force at the rotational shaft attachment groove 7 ″ surface position that is symmetrical to this, sufficient strong caulking cannot be performed, and the eccentric weight 3 from the rotational shaft 2 It is not enough to reliably prevent the falling out of '', and there is a drawback that it is necessary to spend time in the inspection process such as using an adhesive or sufficiently confirming the strength of crimping.

That is, the object of the present invention is to fix the eccentric weight by merely changing the shape of the inner surface of the rotary shaft attachment groove and pressing the end piece on the opening side surface in the rotary shaft direction by means such as caulking. In this case, the surface that directly receives the above pressing force is provided on the inner surface of the rotary shaft attachment groove so that the pressing force such as caulking can be given with a strong force, and the component force in the direction perpendicular to the direction of the center of gravity. Even if a centrifugal force in the direction is applied to the rotating shaft, the force is absorbed and the eccentric weight is securely prevented from coming off from the rotating shaft, no adhesive is required, the inspection process time is shortened, and the manufacturing cost is reduced. The task was to achieve

Another object of the present invention is, in addition to the above-mentioned object, a sufficient strength such as caulking of the eccentric weight on the rotating shaft to prevent the eccentric weight from falling off, thereby further increasing the vibration. In order to reduce the vibration, the weight and volume of the rotary shaft mounting base can be reduced as much as possible to obtain a cylindrical micro-vibration motor capable of generating a larger vibration.

[0023]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
A rotation shaft attachment groove is formed in the rotation shaft attachment base formed on a surface portion of the eccentric weight opposite to the center of gravity direction, and a rotation shaft attachment groove is formed so that the rotation shaft can be inserted from a direction opposite to the center of gravity direction. Is formed into a polygonal surface that is in contact with the peripheral surface of the rotary shaft at four or five points, and both eccentricities of the mounting groove are pressed against the peripheral surface of the rotary shaft by means such as caulking. This can be achieved by attaching the weight to the rotary shaft.

Operation: A method of fixing the eccentric weight 3-1 to the rotary shaft 2 in the cylindrical micro-vibration motor of the first embodiment of the present invention will be described with reference to FIG. In 7-1, when the rotary shaft 2 is laterally inserted into the rotary shaft attachment groove 7-1, the opening 10 is removed,
A surface 11, which contacts the peripheral surface of the rotary shaft 2 at four points,
.. and 14 are formed at equal intervals, so that both opening side surface end pieces 8 sandwiching the opening 10 are arranged from the surface opposite to the center of gravity 6,
Even when pressed in the direction of the rotary shaft 2 by means such as caulking as shown by the dotted line, there are surfaces 12 and 13 which directly receive the above pressing force at the surface position of the rotary shaft attachment groove 7-1 which is symmetrical to this. Therefore, the eccentric weight 3-1 can be firmly fixed to the rotary shaft 2 by applying a pressing force such as caulking with a strong force. When the opening side surface end piece 8 is swaged, the inner surface of the opening side surface end piece 8 becomes a surface 1.
Since it comes into contact with Nos. 1 and 12, a total of four-point caulking (caulking at four points on the peripheral surface of the rotary shaft 2) is performed, so that the eccentric weight 3-1 is used as compared with the conventional method. It can be firmly fixed to the rotary shaft 2, and even if centrifugal force in the component direction of the direction perpendicular to the direction of the center of gravity 6 is given to the rotary shaft 2,
It is possible to reliably prevent the eccentric weight 3-1 from coming off from the rotary shaft 2 by absorbing the force, and to eliminate the need for an adhesive, shorten the inspection process time, and reduce the manufacturing cost.

In the case of the eccentric weight 3-1 shown in FIG. 3, the rotary shaft mounting groove 7-1 has a V-shaped groove bottom at the center of gravity 6 direction.
When the rotary shaft 2 is pushed in the direction of the center of gravity 6, the force is absorbed and the bending of the rotary shaft 2 is prevented.

Referring to FIG. 4, a method of fixing the eccentric weight 3-2 to the rotary shaft 2 in the cylindrical micro vibration motor of the second embodiment of the present invention will be described. The rotary shaft mounting groove 7-of FIG. In No. 2, when the rotary shaft 2 is laterally inserted into the rotary shaft attachment groove 7-2, the surfaces 11, 12, 13, which are in contact with the peripheral surface of the rotary shaft 2 at five points, except for the opening 10.
Since 14 and 15 are formed at equal intervals, the opening 10
Even if the end pieces 8 on both sides of the opening sandwiching the pinch are pressed from the surface in the direction opposite to the center of gravity 6 in the direction of the rotating shaft 2 by means such as caulking as shown by the dotted line, the rotating shaft mounting groove 7 symmetrical to this The eccentric weight 3-2 can be firmly fixed to the rotary shaft 2 by applying a pressing force such as caulking with a strong force because the surfaces 12 and 13 that directly receive the pressing force are provided at the −2 surface position. When the opening side surface end piece 8 is swaged, the inner surface of the opening side surface end piece 8 becomes a surface 1.
Since it comes into contact with Nos. 1 and 12, a total of 5 points of caulking (caulking at 5 points on the peripheral surface of the rotary shaft 2) are performed, so that the eccentric weight 3-2 is used as compared with the conventional method. It can be firmly fixed to the rotary shaft 2, and even if centrifugal force in the component direction of the direction perpendicular to the direction of the center of gravity 6 is given to the rotary shaft 2,
It is possible to reliably prevent the eccentric weights 3-2 from coming off from the rotary shaft 2 by absorbing the force, and to eliminate the need for an adhesive, shorten the inspection process time, and reduce the manufacturing cost.

Referring to FIG. 5, the operation for carrying out another object of the present invention will be described. The rotary shaft mounting base 3b.
Is two small rotary shaft attachment bases 3b-1 and 3b in the axial direction.
-2, and the intermediate part that leads to the reduction of the vibration force is deleted, the weight and volume of the rotary shaft attachment base 3b are reduced, and as a result, the eccentric weight 3-3 of large vibration force is reduced. Is forming.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
FIG. 2 is an explanatory view of a cylindrical micro-vibration motor as a first embodiment in which the eccentric weight 3-1 is attached to the rotary shaft 2 by pressing means such as caulking. FIG. FIG. 3 is a partial view in which the weight 3-1 is attached by pressing means such as caulking. FIG. 3 shows the eccentric weight 3-1 to the rotating shaft 2 of the first embodiment of the present invention by pressing means such as caulking. It is explanatory drawing at the time of sticking. Hereinafter, a cylindrical micro vibration motor according to a first embodiment of the present invention will be described with reference to FIGS.

Not only this embodiment but also the embodiment of the present invention described below, as shown in FIG.
The eccentric weight is attached to the rotary shaft 2 of the cylindrical micromotor 1 in the same manner, and in FIG. 1, an eccentric weight 3-1 described later is fixed to the rotary shaft 2 by a caulking means described later. 1 and 2 show a state in which the eccentric weight 3-1 is fixed to the rotary shaft 2 by the method shown in FIG.

As is apparent from FIGS. 1 and 2, the eccentric weight 3-1 (the same applies to the eccentric weights 3-2 and 3-3 described later) has a semicircular shape when viewed in the axial direction. However, it is similar to the known eccentric weight in that it is formed using a tungsten alloy or the like having a large specific gravity so that sufficient vibration can be obtained and suitable for adopting a means such as caulking.

Assuming that the eccentric weight 3-1 is formed in a cylindrical shape, the eccentric weight 3-1 extends in the axial direction so that the axis center of the eccentric weight 3-1 coincides with the axis center of the rotary shaft 2. The rotary shaft mounting base 3b having the number 1 is formed on the surface side opposite to the weight 3a in the direction of the center of gravity 6 so as to project slightly higher than the rotary shaft mounting base 3b. The rotary shaft attachment base portion 3b is formed with two opening side surface end pieces 8 projecting from both sides of the rotary shaft attachment groove 7-1 to the surface side opposite to the center of gravity 6, and the width thereof is equal to that of the rotary shaft 2. The diameter of the rotary shaft 2 is approximately equal to the size of the rotary shaft 2, and the rotary shaft 2 has a side surface in which the rotary shaft attachment groove 7-1 is inserted to mount the eccentric weight 3-1 on the rotary shaft 2. .

From the side of the rotary shaft 2, the rotary shaft mounting groove 7-
When 1 is inserted and the eccentric weight 3-1 is attached to the rotary shaft 2, the opening 10 of the rotary shaft attaching groove 7-1 is removed,
A surface 11, which contacts the peripheral surface of the rotary shaft 2 at four points,
, 14 are formed at equal intervals on the inner surface of the rotary shaft mounting groove 7-1.

For this purpose, after inserting the rotary shaft attachment groove 7-1 into the rotary shaft 2 from the side and mounting the eccentric weight 3-1 on the rotary shaft 2, both opening side surfaces sandwiching the opening 10 are formed. The end piece 8 is pressed from the surface opposite to the center of gravity 6 to the position indicated by the dotted line in the direction of the rotary shaft 2 by means of caulking or the like using an appropriate jig to open the rotary shaft attachment base 3b. The eccentric weight 3-1 is fixed to the rotary shaft 2 by the side end piece 8.

In this way, since the rotary shaft attaching groove 7-1 surface position symmetrical with the pressed opening side surface end piece 8 such as caulking has the surfaces 12 and 13 directly receiving the pressing force. Since a pressing force such as caulking of the opening side surface end piece 8 can be applied with a strong force, the eccentric weight 3-1 can be firmly fixed to the rotating shaft 2. When the opening side surface end piece 8 is swaged, the inner surface of the opening side surface end piece 8 comes into contact with the surfaces 11 and 12, so that a total of four points are swaged (rotating shaft 2
As compared with the conventional method, the eccentric weight 3-1 can be firmly fixed to the rotating shaft 2, and the force distribution in the direction perpendicular to the direction of the center of gravity 6 can be achieved. Even if a centrifugal force is applied to the rotary shaft 2, the centrifugal force can be sufficiently received, and the eccentric weight 3-1 from the rotary shaft 2 can be received.
It is possible to surely prevent the adhesive from coming off, eliminate the need for an adhesive, shorten the inspection process time, and reduce the manufacturing cost.

In the case of the eccentric weight 3-1 shown in FIG. 3, the rotary shaft mounting groove 7-1 is V at the groove bottom in the direction of the center of gravity 6.
When the rotary shaft 2 is pushed in the direction of the center of gravity 6, the V-shaped groove 15 absorbs the force and the rotary shaft 2 has a groove bottom 15.
We are trying to prevent the bend of the.

The cylindrical microvibration motor of the present invention will be described with reference to FIG. 4. In this motor, the eccentric weight 3-2 having the shape shown in FIG. Since it is fixed by using, and the outer shape is similar to that shown in FIGS. 1 and 2, it will be described with reference to FIGS. 1 and 2.

The eccentric weight 3-2 of the second embodiment differs from the eccentric weight 3-1 only in the shape of the inner surface of the rotary shaft mounting groove 7-2 provided in the rotary shaft mounting base 3b.
When the rotary shaft mounting groove 7-2 is attached to the rotary shaft 2 by inserting the rotary shaft mounting groove 7-2 into the rotary shaft 2 from the side, the rotary shaft mounting groove 7-2 is mounted on the rotary shaft 2. Opening 1 of groove 7-2
Except for 0, the surface 1 that touches the peripheral surface of the rotating shaft 2 at 5 points
1, 12, 13, 14, 15 in the rotary shaft mounting groove 7-2
Are formed at equal intervals on the inner surface of the.

To this end, the rotary shaft 2 is inserted into the rotary shaft 2 from the side thereof to mount the eccentric weight 3-2 on the rotary shaft 2 and then the opening side faces sandwiching the opening 10 are provided. The end piece 8 is pressed from the surface opposite to the center of gravity 6 to the position indicated by the dotted line in the direction of the rotary shaft 2 by means of caulking or the like using an appropriate jig to open the rotary shaft attachment base 3b. The eccentric weight 3-1 is fixed to the rotary shaft 2 by the side end piece 8.

In this way, similarly to the eccentric weight 3-1, the surface of the rotary shaft mounting groove 7-2 symmetrical to the pressed opening side surface end piece 8 such as caulking is directly exposed to the above pressing force. Since there are 12 and 13, it is possible to apply a pressing force such as caulking the opening side surface end piece 8 with a strong force.
The eccentric weight 3-2 can be firmly fixed to the rotary shaft 2.
When the opening side surface end piece 8 is caulked, the opening side surface end piece 8 is
Since the inner surface of is contacted with the surfaces 11 and 12, a total of 5 points of caulking (caulking in contact at 5 points on the peripheral surface of the rotary shaft 2) are performed. 3-2 can be firmly fixed to the rotary shaft 2, and even if a centrifugal force in the component direction perpendicular to the direction of the center of gravity 6 is applied to the rotary shaft 2, the centrifugal force can be sufficiently received, and the rotary shaft 2 Be sure to prevent the eccentric weight 3-2 from coming off,
Adhesives are not required, inspection process time can be shortened, and manufacturing cost can be reduced.

Further, unlike the case of the eccentric weight 3-1, in the case of the eccentric weight 3-2, the rotary shaft 2 is strongly centered on the bottom of the rotary shaft attaching groove 7-1 facing the opening 10 by caulking. When pushed in six directions, the force can be received by the bottom surface 15, so that the eccentric weight 3-2 can be more firmly fixed to the rotary shaft 2 by means such as caulking.

FIG. 5 shows an eccentric weight 3-3 showing a third embodiment of the present invention. The method of fixing the eccentric weight 3-3 to the rotary shaft 2 is as described above. However, in the case of the eccentric weight 3-3, the volume and weight of the rotary shaft attachment base 3b that does not contribute to the generated vibration are further reduced. In order to reduce the number, the rotary shaft mounting base 3b is further divided in the axial direction so as to have two intermediate parts, so that the rotary shaft mounting bases 3b-1 and 3b- are divided into two parts.
It is formed by 2.

According to the rotary shaft mounting base 3b formed by the rotary shaft mounting bases 3b-1 and 3b-2 without the intermediate portion, since the weight is greatly reduced, the cylindrical micro-vibration is performed. The vibration efficiency of the motor can be greatly enhanced. In this case, the two rotary shaft attachment bases 3b-1 and 3b-2 can be fixed to the rotary shaft 2 by swaging at the same time by using the jig used for the eccentric weights 3-1 and 3-2, so there is no problem. .

[0043]

According to the present invention, not only more vibration can be obtained as the eccentric weight in the ultrafine cylindrical micro-vibration motor than in the conventional case, but also when the eccentric weight is attached to the rotary shaft, it is extremely effective. Since it can be firmly fixed, it is possible to improve the quality and reduce the inspection process time without the need for an adhesive bonding process.

[Brief description of the drawings]

FIG. 1 is a cylindrical micro-vibration model in which the eccentric weight according to the first and second embodiments of the present invention is fixed to a rotary shaft.
FIG.

FIG. 2 is an explanatory view of a portion in which the eccentric weight according to the first and second embodiments of the present invention is fixed to a rotary shaft.

FIG. 3 is an explanatory diagram of an eccentric weight according to the first embodiment of the present invention and a method of fixing the eccentric weight to a rotating shaft.

FIG. 4 is an explanatory diagram of an eccentric weight according to a second embodiment of the present invention and a method of fixing the eccentric weight to a rotating shaft.

FIG. 5 is an explanatory diagram of an eccentric weight according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional eccentric weight and a method of fixing the eccentric weight to a rotating shaft.

7 to 9 are explanatory views of a conventional eccentric weight that eliminates the drawbacks of FIG. 6 and a method of fixing the eccentric weight to a rotating shaft.

[Explanation of symbols]

 1 Cylindrical Micro Motor 2 Rotation Shaft 3-1, 3-2, 3-3, 3 ', 3 "Eccentric Weight 3a, 3'a, 3" a Weight 3b, 3'b, 3 " b rotary shaft mounting base 4 shaft hole 5 caulking part 6 center of gravity 7-1, 7-2, 7 ', 7' 'rotary shaft mounting groove 8, 8'open side end piece 9 inner surface portion 10 opening 11・ ・ ・ ・ ・ ・ 15 sides

Claims (2)

[Claims] 1. A cylindrical micro-vibration motor in which an eccentric weight attached to a rotary shaft of a cylindrical micro-motor is rotated to obtain vibration due to a centrifugal force. The rotary shaft mounting base formed on the surface portion is formed with a rotary shaft mounting groove into which the rotary shaft can be inserted from a direction opposite to the direction of the center of gravity, and the inner surface of the rotary shaft mounting groove is formed on the peripheral surface of the rotary shaft or 4 or The eccentric weight is attached to the rotary shaft by forming a polygonal surface that is in contact at five points, and pressing both open ends of the attachment groove against the peripheral surface of the rotary shaft by means such as caulking. A cylindrical micro-vibration motor. 2. The cylinder according to claim 1, wherein the rotary shaft mounting base forming the rotary shaft mounting groove is formed by cutting the rotary shaft mounting groove into a plurality of parts in the axial direction to reduce weight and volume. Type micro vibration motor.