JP3048743U - Small motor for vibration source - Google Patents

Abstract

(57) [Summary] [Object] To provide a small-sized motor for a vibration source, which does not require high processing accuracy, does not expose an eccentric weight, and is less durable to bend a drive shaft due to an impact. [Structure] A drive shaft (1) protruding from a motor body (10)
1) A small motor for a vibration source having an eccentric weight (12) attached thereto, the motor body (10) having an opening (21) at one end into which the motor body (10) fits, and the driving at the other end. A cylindrical cap body (20) having an end surface (23) having a through hole (22) into which the tip of the shaft (11) is loosely inserted.
The eccentric weight (12) is housed inside and fitted.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a small motor for a vibration source, and more specifically, is housed in a small and thin information device such as a mobile phone, a pager, a wristwatch, etc., and is used to notify an information signal such as an incoming call by vibration. The present invention relates to a small motor for a vibration source.

Conventionally, as a small motor for a vibration source of this type, a “flat motor” and a “small-diameter cylindrical motor” have been used due to a demand for miniaturization.

The above “flat motor” has a structure in which the drive shaft direction is thin and has a relatively large diameter but is flat, so that it can be stored in a thin device. The “small-diameter cylindrical motor” has a length The length in the direction of the drive shaft is relatively long, but the diameter is reduced so that it can be accommodated in thin equipment. In both cases, an eccentric weight is attached to the drive shaft, and vibration is obtained by rotation of the eccentric weight.

[0004] The above-mentioned "flat motor" has an advantage that a large output can be obtained relatively easily, but has a problem that the amplitude direction of the vibration is in the direction of the uneven plane, and the vibration is hardly transmitted to the user. ing. In other words, these thin devices such as mobile phones, pagers, and wristwatches are often held with their planes parallel to the user's body in most cases, and in this state, vibrations are generated in the direction of the planes. If it occurs, the amplitude of the vibration will be parallel to the user's body, making it difficult for the vibration to be transmitted to the user's body.

On the other hand, the “small-diameter cylindrical motor” has an advantage that vibration is easily transmitted to the user's body because vibration occurs in the thickness direction of a flattened device such as a mobile phone, a pager, an arm clock and the like. However, there is a problem that it is difficult to obtain a large output by reducing the diameter.

It is not always possible to increase the output of a “small-diameter cylindrical motor”, and a motor with sufficient output for a vibration source has been developed. If the outer diameter is 5 mm, for example, the diameter of the drive shaft is 1 mm or less, and if the outer diameter is 4 mm, it is difficult to obtain a desired output unless the diameter of the drive shaft is 0.5 mm or less. However, when an eccentric weight is attached to such a thin drive shaft, the drive shaft is bent by an impact, causing a problem that causes a failure.

The conventional example shown in FIGS. 4 and 5 is proposed by the present inventors as “Japanese Utility Model Application No. 6-14482”, and the drive shaft 11 has a diameter of 1 mm or less. In a small motor for a vibration source having an eccentric weight 12 attached to a shaft 11, a holder 30 for holding the motor body 10 is attached to the motor body 10, and the holder 30 is a substrate longer than the entire length of the motor body 10. A pair of clamping wings 32, 32, which are bent so as to rise from both side edges of the substrate portion 31 and clamp the outer peripheral portion of the motor body 10 from both sides by a spring force; Locking claw portions 32a, 32a, 32a,... For locking the front and rear ends of the motor body 10 held at both ends in the longitudinal direction of the motor shaft 32, and a tip of the drive shaft 11 bent at a right angle from one end of the substrate portion 31 Bearing part And a bearing plate portion 33 having the following configuration.

However, recently, the efficiency of the output of the “small-diameter cylindrical motor” has advanced, and a long vibration can be used as the eccentric weight 12 in order to obtain a large vibration force. However, if a long one is used for the eccentric weight 12, the drive shaft 11 becomes longer, and there is a problem that it is difficult to obtain the machining accuracy of the bearing plate 33.

In addition, if the drive shaft 11 is long, the conventional example shown in FIGS. 4 and 5 has a problem that the probability that the rotating eccentric weight 12 comes into contact with other devices or the like is increased. Was.

[0010]

[Problems to be solved by the invention]

 In view of the above, the present invention has been made to solve the above problems, and does not require high machining accuracy, does not expose the eccentric weight, and has a low danger of the drive shaft being bent by an impact. It is an object of the present invention to provide a small motor for motor vehicles.

[0011]

[Means for Solving the Problems]

 In order to solve the above problem, the configuration of the present invention is to provide a small motor for a vibration source in which an eccentric weight 12 is attached to a driving shaft 11 protruding from the motor main body 10. An eccentric weight 12 is housed inside a cylindrical cap body 20 having an opening 21 into which the main body 10 fits and an end face 23 having a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. This is a technical measure characterized by fitting.

Therefore, the small motor for a vibration source according to the present invention has an effect of accommodating the eccentric weight 12 in the cylindrical cap body 20.

Since the end face 23 having the through hole 22 into which the tip of the drive shaft 11 is loosely inserted is provided at the other end of the cylindrical cap body 20, an impact is applied to the small motor for the vibration source of the present invention. Then, it is inevitable that the drive shaft 11 is bent by the external force. However, the range in which the drive shaft 11 bends is limited to the clearance between the through hole 22 and the drive shaft 11 loosely inserted into the through hole 22, and if the range in which the drive shaft 11 bends is small, the drive shaft 11 is bent. 11 has the function of returning to the original state when the external force is released.

Since the drive shaft 11 is allowed to bend within a predetermined range as described above, when a large external force is applied to the eccentric weight 12, the external force exerts a buffering action transmitted to the drive shaft 11. is there.

Next, a second aspect of the present invention is a small-sized motor for a vibration source in which an eccentric weight 12 is attached to a drive shaft 11 protruding from the motor body 10. The eccentric weight 12 is housed inside a cylindrical cap body 20 having an opening 21 in which the shaft 10 is fitted and an end face 23 having a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. The cylindrical cap body 20 is stepped up in the middle of the opening 21 at a position in the middle, and the stepped portion 24 formed by the stepped diameter expansion of the inner peripheral surface of the cylindrical cap body 20 is formed in the motor body 10. A technical measure characterized by the fact that the stopper is used as a fitting stopper.

Therefore, the small motor for a vibration source according to the present invention is characterized in that, in addition to the function of claim 1, the cylindrical cap body 20 has a step-like enlarged diameter of the opening 21 at a partway, and the cylindrical cap has a cylindrical cap. Since the stepped portion 24 formed by the stepwise expansion of the inner peripheral surface of the body 20 is used as a fitting stopper of the motor main body 10, the function of easily determining the fitting position of the cylindrical cap body 20 is exhibited.

Next, a third aspect of the present invention is directed to a small-sized motor for a vibration source in which an eccentric weight 12 is attached to a drive shaft 11 protruding from the motor body 10. The eccentric weight 12 is housed inside a cylindrical cap body 20 having an opening 21 in which the shaft 10 is fitted and an end face 23 having a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. A technical means is provided in which concave portions 26, 26 which are fitted and which protrude inward are formed on the peripheral surface 25 of the cylindrical cap body 20 and serve as fitting stoppers of the motor body 10.

Therefore, the small motor for a vibration source according to the present invention is changed from “claim 2” to “expanding the diameter of the opening 21 site side of the cylindrical cap body 20 stepwise”, and The outer peripheral surface 25 protrudes inward as a fitting stopper of the motor body 10 ", so that the function of easily finding the fitting position of the cylindrical cap body 20 is the same as that of claim 1. Further, the inner diameter of the cylindrical cap body 20 can be made the same as the outer diameter of the motor body 10, and the eccentric weight 12 has an effect of increasing the amount of eccentricity.

[0019]

[Embodiment of the invention]

 Next, an embodiment of the present invention will be described below with reference to the accompanying drawings. In the figure, reference numeral 10 denotes a motor body of a small motor for a vibration source. The motor main body 10 used here is a normal micro motor having a small diameter and a small size. In this embodiment, a DC brush motor having an outer diameter of 4 mm is used. In the motor body 10, a permanent magnet as a stator, a rotor having a coil wound around an iron core, a commutator connected to the rotor, and a brush contacting the commutator are housed. The distal end (right end in FIG. 1) of the drive shaft 11 passing through the center penetrates outward through the distal bearing portion of the motor body 10, and the other end is supported by the bearing portion of the bracket 10a. Is the same as before.

As described above, the drive shaft 11 of the small-diameter motor body 10 is also naturally thin. In a normal micromotor, this drive shaft 11 has a diameter of 1.5 mm or more, and there is no particular problem in strength, but such a thick drive shaft 11 is attached to the motor body 10 having an outer diameter of 4 mm in this embodiment. If used, only the dimension (4-1.5) /2=1.25 (mm) in the radial direction can be used for the thickness of the case and the size of the stator and the rotor. Assuming a clearance of 35 mm and a stator-rotor clearance of 0.2 mm, the remaining gap available for stator thickness and rotor radial width is 1.25-0.35-0. 2 = 0.7 (mm). With such dimensions, it is not possible to obtain a sufficient magnetic field with a permanent magnet or a strong electromagnetic field with a coil. ) Cannot be obtained.

In order to reduce the diameter of the motor body 10 to, for example, 5 mm, the diameter of the drive shaft 11 needs to be 1 mm or less. Therefore, in the present invention, it is assumed that the diameter of the drive shaft 11 is 1 mm or less, and the eccentric weight 12 is attached to the drive shaft 11.

Since the eccentric weight 12 has a limitation in terms of space in the radial direction to increase the amount of eccentricity, recently, the volume is set as large as possible (long setting) with a high specific gravity material such as tungsten. As the weight increases and the length increases, the impact force is doubled in accordance with the length. When such a heavy object is held by the drive shaft 11 having a diameter of 1 mm or less, the impact resistance is reduced. May not be possible.

Therefore, the present invention provides an end face 2 having an opening 21 at one end of the motor main body 10 into which the motor main body 10 fits, and a through hole 22 at the other end into which the tip of the drive shaft 11 is loosely inserted. The eccentric weight 12 is housed inside the cylindrical cap body 20 having the cylindrical cap 3 and fitted therein.

The cylindrical cap body 20 is usually made of metal, and a cylindrical peripheral surface (without reference numeral) and an end surface 23 may be separately prepared and connected and fixed. A large-diameter cylinder having the diameter that this cylinder recommends may be fitted and fixed to the opening at the tip of the cylinder, but if it is integrally molded, a cylinder with good dimensional accuracy can be obtained. In the illustrated embodiment, an integrally molded cylindrical cap body 20 is used. It is a matter of course that the cylindrical cap body 20 may be made of a synthetic resin and used in place of metal.

The opening 21 of the cylindrical cap body 20 has an inner diameter corresponding to the outer diameter of the motor main body 10. The cap body 20 is connected to the same center axis. It is desirable to set the dimension of the motor main body 10 to be fitted into the cylindrical cap body 20 large so that the same central axis can be accurately maintained and the strength of the fitting connection part can be maintained large.

The motor main body 10 and the cylindrical cap body 20 may be fitted to each other by press-fitting or other known engagement so as not to fall off in a normal use state. Adhering inseparably is not a problem.

The through hole 22 provided in the end face 23 at the other end of the cylindrical cap body 20 is for bearing by loosely inserting the drive shaft 11, but does not surely bear the drive shaft 11. The bearings have relatively large clearances. That is, the clearance between the drive shaft 11 and the through hole 22 in the present invention is about one decimal place in millimeters. It is about 0.1 to 0.2 mm.

If the clearance between the drive shaft 11 and the through hole 22 is set to an accuracy of about one decimal place in millimeters, the positional accuracy of the through hole 22 is not required to be very accurate. Although the position of the through hole 22 can be easily drilled at an accurate position, if the clearance is large, even if the drive shaft 11 is slightly deformed, the bearing will not be hindered, the manufacturing becomes easy, and the yield is improved. Things.

When the clearance between the drive shaft 11 and the through hole 22 is increased, the drive shaft 11 may be bent by an impact. Even if the drive shaft 11 is lengthened, most of the bend of the drive shaft 11 is most easily penetrated by the eccentric weight 12, so that a portion near the motor body 10 is most easily bent. However, with respect to this bend, the displaceable distance of the tip (the right end in FIG. 1) of the drive shaft 11 is restricted by the clearance, so that even if the drive shaft 11 bends, the bend is within the range that can be restored. You can do it.

In addition, the drive shaft 11 may be bent into a substantially U-shape by which the eccentric weight 12 receives a large gravity due to an impact and projects in a direction opposite to the impact force. However, with respect to this bend, the drive shaft 11 bends around one end of the motor main body 10 (single right in FIG. 1) as a fulcrum, so that the gravity applied to the eccentric weight 12 is buffered and the drive shaft 11 bends. It is to prevent.

The eccentric weight 12 has a limitation in terms of space in the radial direction to increase the amount of eccentricity (usually, it is required that the eccentric weight 12 be smaller than the outer diameter of the motor main body 10 to be incorporated in an apparatus). Recently, it has been formed by setting the volume as large as possible (long setting) with a high specific gravity material such as tungsten. The eccentric weight 12 has a substantially semi-circular cross section as shown in FIG. 2 so that the drive shaft 11 is inserted into the center axis portion of the peripheral surface and is attached to the drive shaft 11. There is something.

Then, the above-mentioned cylindrical cap body 20 is fitted into the motor main body 10 with the eccentric weight 12 housed therein, and the tip of the drive shaft 11 is inserted into the through hole 22 as described above. It is made to do.

Next, a second aspect of the present invention is to provide a small motor for a vibration source in which an eccentric weight 12 is attached to a drive shaft 11 protruding from the motor body 10. The eccentric weight 12 is housed inside a cylindrical cap body 20 having an opening 21 in which the shaft 10 is fitted and an end face 23 having a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. The cylindrical cap body 20 is stepped up in the middle of the opening 21 at a position in the middle, and the stepped portion 24 formed by the stepped diameter expansion of the inner peripheral surface of the cylindrical cap body 20 is formed in the motor body 10. A technical measure characterized by the fact that the stopper is used as a fitting stopper.

That is, in the present invention, in addition to the invention of “Claim 1”, the cylindrical cap body 20 has a step-like enlarged diameter on the side of the opening 21 partway from the middle, and a step on the inner peripheral surface of the cylindrical cap body 20. The stepped portion 24 generated by the shape expansion serves as a fitting stopper for the motor main body 10.

When the cylindrical cap body 20 is fitted to the motor body 10, the fitting amount of the motor body 10 into the opening of the cylindrical cap body 20 is not constant unless the fitting amount is small. The core of the body 20 may be displaced, and if the amount of fitting is too large, the inner surface of the end face 23 of the tubular cap body 20 may come into contact with the tip of the eccentric weight 12. Therefore, the above-mentioned problem is solved by using the step portion 24 as a fitting stopper.

Next, a third aspect of the present invention is a small-sized motor for a vibration source in which an eccentric weight 12 is attached to a drive shaft 11 protruding from the motor body 10. The eccentric weight 12 is housed inside a cylindrical cap body 20 having an opening 21 in which the shaft 10 is fitted and an end face 23 having a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. The cylindrical cap body 20 is fitted and provided with concave portions 26, 26 protruding inward and serving as a fitting stopper of the motor body 10 on the peripheral surface 25 of the cylindrical cap body 20.

That is, in the present invention, the recesses 26, 26 serve as fitting stoppers for the motor main body 10, instead of the step portions 24 of the “claim 2”. In the illustrated example, the recesses 26, 26 are formed by denting a predetermined location on the peripheral surface of the cylindrical cap body 20 from the outer surface side to the inner side with a punch or the like. A groove-shaped concave portion may be provided inside the entire circumference of the cap body 20, or a cut-and-raised portion (not shown) may be provided locally.

When the recesses 26 are used as fitting stoppers for the motor body 10, the inner diameter of the cylindrical cap body 20 is smaller than that of the first and second inventions, as described above. It can be set to be large, and strong vibration can be obtained.

In the drawings, reference numerals 13 and 13 indicate lead wires.

[0040]

[Effect of the invention]

 Since the present invention uses the cylindrical cap body 20 as described above, the rotating eccentric weight 12 is not exposed, and the eccentric weight 12 does not come into contact with other devices. A motor can be provided.

The cylindrical cap body 20 has an end face 23 having an opening 21 into which the motor body 10 is fitted at one end and a through hole 22 into which the tip of the drive shaft 11 is loosely inserted at the other end. As a result, by fitting the motor main body 10 into the opening 21, the core of the cylindrical cap body 20 and the motor main body 10 can be aligned, and the through hole 22 loosely inserts the leading end of the drive shaft 11. It is possible to provide a small motor for a vibration source, which has a small diameter so that the drive shaft 11 is less likely to bend by an impact.

Further, the invention of claim 2 provides the above-described effect by using the stepped portion 24 provided on the inner peripheral surface of the cylindrical cap body 20 as a fitting stopper, in addition to the above-described effects. It is possible to provide a small-sized motor for a vibration source with high reliability in which the core between the tubular cap body 20 and the motor body 10 does not shift and the eccentric weight 12 does not contact the tubular cap body 20.

According to the invention of claim 3, in addition to the effect of claim 2, in addition to the effect of claim 2, the inner diameter of the cylindrical cap body 20 can be set large, and a small motor for a vibration source capable of obtaining strong vibration. Can be provided.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of an essential part showing an embodiment of a small motor for a vibration source of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a vertical sectional front view of a main part of another embodiment.

FIG. 4 is a front view of a conventional example.

FIG. 5 is a left side view of the conventional example shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Motor main body 11 Drive shaft 12 Eccentric weight 20 Cylindrical cap body 21 Opening 22 Through hole 23 End surface 24 Step part 25 Peripheral surface 26 Depression

Claims (3)

[Utility model registration claims] 1. A small motor for a vibration source comprising an eccentric weight (12) attached to a drive shaft (11) projecting from the motor body (10), wherein the motor body (10) has one end at one end.
Has an opening (21) into which the drive shaft (1) fits.
An end face (2) having a through hole (22) into which the tip of 1) is loosely inserted.
The cylindrical cap body (20) having 3) is attached to the eccentric weight (1).
2. A small motor for a vibration source, wherein 2) is housed and fitted inside. 2. A small motor for a vibration source having an eccentric weight (12) attached to a drive shaft (11) projecting from the motor body (10), wherein the motor body (10) has one end at one end.
Has an opening (21) into which the drive shaft (1) fits.
An end face (2) having a through hole (22) into which the tip of 1) is loosely inserted.
The cylindrical cap body (20) having 3) is attached to the eccentric weight (1).
The cylindrical cap body (20) is fitted inside the cylindrical cap body (20). The cylindrical cap body (20) has an opening (21) part side partly enlarged stepwise from the middle, and the inner peripheral surface of the cylindrical cap body (20) is A small motor for a vibration source, characterized in that a step (24) generated by the step-like diameter enlargement is used as a fitting stopper of the motor body (10). 3. A small motor for a vibration source comprising an eccentric weight (12) attached to a drive shaft (11) projecting from the motor body (10), wherein the motor body (10) has one end at one end.
Has an opening (21) into which the drive shaft (1) fits.
An end face (2) having a through hole (22) into which the tip of 1) is loosely inserted.
The cylindrical cap body (20) having 3) is attached to the eccentric weight (1).
2) is housed and fitted inside thereof, and concave portions (26, 26) protruding inward to serve as fitting stoppers for the motor body (10) are formed on the peripheral surface (25) of the cylindrical cap body (20). A small motor for a vibration source, wherein the motor is provided.