JP2003071382A - Weight and vibration motor equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damage-preventable weight and a vibration motor equipped with the weight. SOLUTION: This weight 1 to be fit to a rotary shaft 5 is provided with an insertion groove 7 for inserting the shaft 5. Erected parts 9 are formed on both sides of the groove 7 so that they are faced to each other and have almost uniform thickness. The inner peripheral surfaces 9b and the outer peripheral surfaces 9c of the parts 9 are curved in arc shapes so that the surface 9b skirt the outer peripheral surface 5a of the shaft 5. The distance H between the tip parts 9a of the parts 9 is made shorter than the diameter R of the shaft 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight attached to a rotary shaft and a vibration motor to which the weight is attached.

[0002]

2. Description of the Related Art As this type of weight, for example, the one disclosed in Japanese Patent No. 2518781 is known. This is because, as shown in FIG. 18, the weight 101 has an insertion groove 10 for inserting the rotary shaft 105 of the motor from the vertical direction.
3 is formed, and in the insertion groove 103, standing portions 107 that stand upright are provided so as to face each other.
The inner side surface 107a of the upright portion 107 is a vertical surface, the outer side surface 107b is a tapered surface, and the upright portion 107 is caulked toward the rotary shaft with a die having a shape along the taper surface. 101 is fixed.

[0003]

However, in the above technique, when the upright portion 107 is caulked toward the rotary shaft,
A crack K may occur in the base portion 107c of the standing portion 107. It is considered that this is because the thickness of the upright portion 107 is not constant, and when the upright portion 107 is caulked, the amount of displacement of the upright portion 107 is large, so that stress easily concentrates on the base portion 107c of the upright portion 107.

Therefore, an object of the present invention is to provide a weight capable of preventing the standing portion from being damaged during crimping and a vibration motor having the weight attached thereto.

[0005]

According to a first aspect of the present invention, in a weight attached to a rotary shaft, an insertion groove into which the rotary shaft is inserted is provided, and standing portions face each other on both sides of the insertion groove. The standing portion has a substantially uniform thickness, and the inner side surface and the outer side surface of the standing portion facing each other are curved in an arc shape along the outer peripheral surface of the rotating shaft inserted into the insertion groove. The interval between the tips of the opposing standing portions is characterized by being narrower than the diameter of the rotary shaft inserted into the insertion groove.

According to the first aspect of the present invention, after the rotary shaft is inserted into the weight insertion groove from the horizontal direction, the standing portion is caulked to attach the weight to the rotary shaft. Since the thickness of the standing portion is substantially uniform, a uniform force is applied to the entire standing portion when the standing portion is crimped. Further, since the inner side surface and the outer side surface of the upright portion are curved in an arc shape so as to follow the outer peripheral surface of the rotating shaft, the amount of displacement of the upright portion during caulking can be small. Therefore, stress is less likely to be concentrated on the base of the upright portion, and cracks are less likely to occur at the base of the upright portion, so damage to the upright portion can be prevented during caulking. In addition, the inner surface and the outer surface of the upright portion are formed in an arc shape, and the distance between the tip portions of the upright portion is made narrower than the diameter of the rotating shaft, so that the inner surface of the upstanding portion and the outer peripheral surface of the rotating shaft are separated from each other. Since the distance is short, the amount of caulking at the upright portion can be small.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the groove bottom portion of the insertion groove is constituted by a plurality of continuous flat surfaces.

According to the invention described in claim 2, claim 1
With the same effect as the invention described in (1), by configuring the groove bottom part with a plurality of flat surfaces, when the rising portion is caulked, the outer peripheral surface of the rotating shaft is pressed against the plurality of flat surfaces, and Since the weight can be firmly fixed to the rotary shaft without using a chemical agent or the like, the manufacturing cost can be reduced.

The invention according to claim 3 is the invention according to claim 1 or 2.
It is characterized in that it is mounted by inserting the rotating shaft from the horizontal direction into the insertion groove of the weight described in.

In the invention described in claim 3, claim 1
Alternatively, it is possible to provide a vibration motor having the same effects as those of the invention described in item 2.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 2 to 6
As shown in FIG. 3, the weight 1 is a vibration motor 3 indicated by a chain double-dashed line.
The vibration is generated by rotating the weight 1 attached to the rotation shaft 3 and rotating the weight 1. It should be noted that such a vibration motor 3 is used, for example, when notifying a pager or the like of a call by vibration.

In this embodiment, the weight 1 has a substantially semicircular shape when viewed from the axial direction (horizontal direction) of the rotary shaft 5 of the vibration motor 3. The material of the weight 1 is not particularly limited, but it is preferable to use a material having a large specific gravity and rich malleability,
In the present embodiment, W-Ni-Fe system, W-Ni-Cu system
System, W-Mo-Ni-Fe system, and other tungsten alloys.

As shown in FIG. 1A, the weight 1 has an insertion groove 7 into which the rotary shaft 5 is inserted in the horizontal direction.
Left and right upright portions 9 that rise above the weight 1 are provided on both sides of the insertion groove 7.

The standing portion 9 has a substantially uniform thickness from the base portion 9d to the tip portion 9a, and is provided along the horizontal direction in which the rotary shaft 5 of the vibration motor 3 is inserted. Standing part 9
Are opposed to each other, and the inner side surface 9b and the outer side surface 9c of the standing portion 9 have an outer peripheral surface 5a of the rotary shaft 5 inserted into the insertion groove 7.
It is curved in an arc shape so as to follow. In the present embodiment, the inner side surface 9b and the outer side surface 9c of the upright portion 9 have the rotating shaft 5
A circular arc similar to the outer peripheral surface 5a is formed. When the rotary shaft 5 is inserted into the insertion groove 7, a predetermined gap S is formed between the inner side surface 9b of the upright portion 9 and the outer peripheral surface 5a of the rotary shaft 5, and a play for inserting the rotary shaft 5 is formed. Is taking.

Further, the distance H between the tips 9a of the upright portions 9
Is smaller than the diameter R of the rotary shaft 5, and the insertion groove 7
The rotary shaft 5 cannot be inserted through the opening (between the tip end portions 9a of the standing portions 9), and the rotary shaft 5 is inserted into the insertion groove 7 from the horizontal direction.

In the present embodiment, the groove bottom portion 11 is composed of two flat surfaces 11a and 11b which come into contact with the outer surface of the rotary shaft 4, and its cross section is substantially V-shaped. When the rotating shaft 5 is pushed downward, the flat surfaces 11a and 11b absorb the pressing force at the contact portions A and B with the outer peripheral surface of the rotating shaft 5 to prevent the rotating shaft 5 from bending. .

Next, the attachment of the weight 1 to the rotary shaft 5 will be described. When attaching the weight 1 to the rotary shaft 5,
First, as shown in FIG. 1A and FIG.
The rotary shaft 5 is inserted into the insertion groove 7. Insert the rotary shaft 5 into the insertion groove 7
Then, the left and right standing portions 9, 9 are caulked toward the rotary shaft 5.

In this embodiment, since the upright portion 9 has a substantially uniform thickness, when the upright portion 9 is caulked, a uniform force is applied to the entire upright portion 9 to prevent a local stress from being generated. . Further, since the inner side surface 9b and the outer side surface 9c of the upright portion 9 are curved in an arc shape along the outer peripheral surface 5a of the rotating shaft 5, the amount of displacement of the upright portion 9 necessary for caulking is reduced. Therefore, the stress is less likely to be concentrated on the base portion 9d of the upright portion 9, and the base portion 9d of the upright portion 9 is less likely to be cracked.
It is possible to prevent the standing portion 9 from being damaged.

Further, the inner side surface 9b and the outer side surface 9 of the rising portion 9 are
By making c a circular arc shape and making the interval H between the tip portions 9a of the standing portions 9 narrower than the diameter R of the rotating shaft 5,
Since the distance between the inner side surface 9b of the upright portion 9 and the outer peripheral surface 5a of the rotary shaft 5 is short (the gap S is narrow), the amount of caulking of the upright portion 9 can be small.

By caulking the standing portion 9 toward the rotating shaft 5, the outer peripheral surface 5a of the rotating shaft 5 is pressed against the inner side surface 9b of the standing portion 9 as shown in FIG. 1 (b).
The contact portions A and B of the flat surfaces 11a and 11b of the groove bottom portion 11 receive a pressing force, and the rotary shaft 5 is strongly pressed against these contact portions A and B.

The groove bottom 11 has two flat surfaces 11a and 11b.
With this configuration, when the upright portion 9 is swaged, the outer peripheral surface 5a of the rotary shaft 5 is pressed against the two contact portions A and B with the flat surfaces 11a and 11b, so that an adhesive agent or the like is not required. Since the weight 1 can be firmly fixed to the rotary shaft 5, the manufacturing cost can be reduced.

Next, other embodiments will be described. In the description, the same parts as those described above are designated by the same reference numerals, and the description thereof will be omitted.

The second embodiment differs from the first embodiment in that the insertion groove 7 is formed only halfway through the weight 1, as shown in FIGS. 7 to 11. Also in the second embodiment, the same operational effect as that of the first embodiment is obtained.

In the third embodiment, as shown in FIGS. 12 to 16, the insertion groove 7 is formed only up to the middle of the weight 1, and the upright portions 9 are formed at intervals in the axial direction. This is different from the first embodiment. In the third embodiment, the weight and weight of the weight 1 can be reduced because the same effect as that of the first embodiment is obtained and the standing portions 9 are formed at intervals in the axial direction.
The vibration efficiency of the vibration motor 3 can be improved.

In the fourth embodiment, as shown in FIG. 17, the groove bottom portion 11 of the insertion groove 7 is composed of three flat surfaces 11c, 11d and 11e which are in contact with the outer peripheral surface 5a of the rotary shaft 5. This is different from the first embodiment. Also in this 4th Embodiment, there exists an effect similar to 1st Embodiment.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the shape of the weight 1 is not limited to the semicircular shape, and may be a fan shape or the like. Further, although two or three flat surfaces are provided in the present embodiment, the present invention is not limited to this, and four or more flat surfaces may be provided.

[0027]

According to the invention described in claim 1, since the inner side surface and the outer side surface of the upright portion having a substantially uniform thickness are curved in an arc shape so as to follow the outer peripheral surface of the rotating shaft, the entire upright portion is formed. Since a substantially uniform force is applied to and the amount of displacement of the upright portion is small, cracks are unlikely to occur at the base of the upright portion, and damage to the upright portion during caulking can be prevented. In addition, the inner surface and the outer surface of the upright portion are formed in an arc shape, and the distance between the tip portions of the upright portion is made narrower than the diameter of the rotating shaft, so that the inner surface of the upstanding portion and the outer peripheral surface of the rotating shaft are separated from each other. Since the distance is short, the amount of caulking at the upright portion can be small.

The invention according to claim 2 has the same effect as that of the invention according to claim 1, and the groove bottom portion is constituted by a plurality of flat surfaces, so that when the standing portion is caulked, the rotary shaft is swaged. Since the outer peripheral surface of the is pressed against the plurality of flat surfaces, the weight can be firmly fixed to the rotating shaft without using an adhesive or the like, so that the manufacturing cost can be reduced.

According to the invention described in claim 3, it is possible to provide a vibration motor having the same effect as that of the invention described in claim 1 or 2.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the weight of FIG. 2, where (a) shows the weight when the rotary shaft is inserted and (b) shows the weight when the upright portion is swaged.

FIG. 2 is a perspective view showing a state in which a rotary shaft is inserted into an insertion groove of a weight according to the first embodiment.

3 is a plan view of the weight of FIG. 2. FIG.

FIG. 4 is a side view of the weight of FIG.

5 is a front view of the weight of FIG. 2. FIG.

FIG. 6 is a rear view of the weight shown in FIG.

FIG. 7 is a perspective view showing a state in which a rotary shaft is inserted into an insertion groove of a weight according to the second embodiment.

8 is a plan view of the weight shown in FIG. 7. FIG.

9 is a side view of the weight of FIG. 7. FIG.

10 is a front view of the weight of FIG. 7. FIG.

11 is a rear view of the weight of FIG. 7. FIG.

FIG. 12 is a perspective view showing a state in which a rotary shaft is inserted into an insertion groove of a weight according to the third embodiment.

13 is a plan view of the weight shown in FIG. 12. FIG.

FIG. 14 is a side view of the weight shown in FIG.

FIG. 15 is a front view of the weight shown in FIG.

16 is a rear view of the weight shown in FIG.

FIG. 17 is a cross-sectional view showing a state where a rotary shaft is inserted in an insertion groove of a weight according to the fourth embodiment.

FIG. 18 is a sectional view showing a conventional weight.

[Explanation of symbols]

Weight 1 3 Vibration motor 5 rotation axes 5a Outer peripheral surface of rotating shaft 7 insertion groove 9 Standing part 9a Standing tip 9b Inside surface of standing part 9c Outer surface of upright portion 9d Stand base 11 groove bottom 11a, 11b, 11c, 11d, 11e Flat surface

Claims (3)

[Claims] 1. A weight attached to a rotating shaft,
The rotating shaft is provided with an insertion groove, and the upright portions are provided on both sides of the insertion groove so as to face each other. The upright portions have a substantially uniform thickness, and the inner side surface and the outer side surface of the upright portion facing each other are substantially uniform. , Is curved in an arc shape along the outer peripheral surface of the rotary shaft to be inserted into the insertion groove, and the interval between the tip portions of the opposing upright portions is narrower than the diameter of the rotary shaft to be inserted into the insertion groove. A weight characterized by that. 2. The weight according to claim 1, wherein the groove bottom portion of the insertion groove is constituted by a plurality of continuous flat surfaces. 3. A vibration motor, characterized in that it is mounted by inserting a rotary shaft in the insertion groove of the weight according to claim 1 or 2 from a horizontal direction.