JP2012005294A - Flat type vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a falling prevention structure for an eccentric weight of a flat type vibration motor capable of firmly preventing the eccentric weight from falling in a radial direction, in which a fixed alignment of the eccentric weight is easy enough to generate no trouble in assembly work.SOLUTION: A periphery part 32c raised from a flat plate part 32b in an axial direction is formed in a rotor frame 32 and is in contact with a rotor magnet 33 and a part of an eccentric weight 34. A notch 32d is formed in the flat plate part 32b and the periphery part 32c by partially cutting off the contact portion of the flat plate part 32b and the periphery part 32c with the eccentric weight 34. A part of the eccentric weight 34 is protruded as a projection 34a from the notch 32d in a radial outside. The eccentric weight 34 has a step part as a hook part 34b in contact with an end face of the notch 32d of the periphery part 32c in the rotor frame 32 and an inner peripheral surface of the periphery part 32c.

Description

  The present invention relates to a flat vibration motor, and more particularly to a structure for preventing an eccentric weight from falling off.

  For example, in a flat vibration motor as disclosed in Japanese Patent Application Laid-Open No. 2004-147468, as an eccentric weight fixing means, the eccentric weight is fixed to the rotor frame by welding with a laser or the like. There are problems such as quality variation and high cost. For this reason, fixing with an adhesive is sometimes used, but fixing strength is weaker than welding and fixing, and the eccentric weight may fall off.

  To solve this problem, for example, as disclosed in JP-A-2004-25064, the rotor frame and the eccentric weight are caulked, or as disclosed in JP-A-2006-192317, a hole is formed in the rotor frame, and the eccentric weight corresponds to the hole. The structure which reinforces fixation fixation is formed by forming and fitting a protrusion.

JP2004-147468 JP 2004-25064 A JP 2006-192317 A

  However, in such a caulking and fitting configuration, it takes time to align the eccentric weight to the rotor frame, which may cause problems in assembly work, and in terms of reinforcing adhesive fixing. There was still a possibility of insufficient reinforcement.

  Accordingly, in view of the above problems, the object of the present invention is to make it possible to easily fix the eccentric weight in a flat vibration motor without causing any trouble in assembling work, and firmly preventing the radial dropout. It is an object of the present invention to provide an eccentric weight drop prevention structure capable of further reinforcing the fixing strength of fixing and fixing an eccentric weight.

  In order to solve the above problems, the eccentric weight drop prevention structure for a flat vibration motor according to the present invention includes a stator portion that supports one end of a support shaft, and an opening of a cylindrical portion that is blocked by the stator portion. A flat vibration motor comprising a cover case for supporting the other end of the rotor, and a rotor frame having a rotor magnet and an eccentric weight that are rotatably supported via a bearing through which a support shaft passes. It has a flat plate part and an outer peripheral part that rises in the axial direction from the flat plate part and comes into contact with a part of the outer peripheral surface of the rotor magnet and the eccentric weight, and the flat plate part and a part of the outer peripheral part are notched at the fixed position of the eccentric weight. A notch is formed, the eccentric weight contacts the inner peripheral surface of the outer peripheral part and is prevented from coming out radially outward, and part of the eccentric weight projects radially outward from the notch, Part that contacts the outer periphery of the eccentric weight At least one of, wherein the engaging portion to prevent the detachment of the radial eccentric weight are formed. The hooking portion of the eccentric weight can be a stepped portion that abuts the end portion of the outer peripheral portion of the rotor frame and the inner peripheral surface. Further, the eccentric weight may be formed with a stepped portion that contacts the notch end surface of the flat plate portion of the rotor frame. Further, a caulking piece for fixing the eccentric weight may be formed on the rotor frame, and in this case, a recess for receiving the caulking piece may be formed on the eccentric weight. Further, the eccentric weight may be formed such that the support shaft side is formed in an arc shape, and the outer peripheral surface of the rotor magnet is in contact with the arc-shaped portion.

  In such a structure for preventing the eccentric weight of the flat vibration motor from falling off, the eccentric weight abuts against the inner peripheral surface of the outer peripheral portion of the rotor frame and is prevented from coming out radially outward, and a part of the rotor frame is notched. Since the protrusion of the eccentric weight and the notch portion of the rotor frame make it possible to easily align the eccentric weight, and the center of gravity is also the radial direction as the eccentric weight protrudes. Since it moves to the outside, the amount of vibration can be increased. Furthermore, since the hooking portion is formed on at least one of the outer peripheral portion of the rotor frame or the portion of the eccentric weight that contacts the outer peripheral portion of the rotor frame, the eccentric weight is prevented from falling off in the radial direction, and the eccentric weight is attached to the rotor frame. It becomes possible to further reinforce the fixing strength of the fixing.

  When a structure that forms a stepped part that contacts the notch end face and the inner peripheral surface of the outer peripheral part of the rotor frame as the hooking part of the eccentric weight, positioning of the eccentric weight and prevention of falling off radially outward The effect can be obtained at the same time. In addition, when the structure of the step portion is formed so as to enclose the notched end portion of the outer peripheral portion of the rotor frame, it is possible to prevent the eccentric weight from falling off in the radial direction.

  Further, in the structure in which the eccentric weight is provided with a stepped portion that contacts the notch end face of the flat plate portion of the rotor frame, it is possible to prevent the eccentric weight from falling off inward in the radial direction.

  In addition, in the structure in which the caulking piece for fixing the eccentric weight to the rotor frame is formed, the eccentric weight can be prevented from dropping in the radially outer side and the inner side and further in the axial direction, and the eccentric weight receives the caulking piece. If these recesses are formed, these effects can be further enhanced.

  Furthermore, with the structure in which the spindle side of the eccentric weight is formed in an arc shape and the outer peripheral surface of the rotor magnet is in contact with this arc-shaped portion, the eccentric weight can be prevented from falling off radially inward. Since the eccentric weight is sandwiched and fixed with the outer peripheral portion of the frame, it is possible to prevent the dropout in the radial direction more firmly and to further reinforce the fixing strength for fixing and fixing the eccentric weight.

  In the flat vibration motor of the present invention, the fixed position of the eccentric weight can be fixed easily, without causing trouble in the assembly work, and by firmly preventing the falling off in the radial direction, the fixing strength of the fixed weight of the eccentric weight can be increased. Further reinforcement is possible.

It is a longitudinal cross-sectional view of the flat vibration motor which concerns on the Example of this invention. (A) is the top view which looked at the rotor part of the flat vibration motor from the back, (B) is the longitudinal cross-sectional view of the rotor part. It is an assembly perspective view of the rotor part. (A) is the top view which looked at the rotor part of the flat vibration motor which concerns on the other Example of this invention from the back surface, (B) is a longitudinal cross-sectional view along the aa line of (A). It is an assembly perspective view of the rotor part.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 is a longitudinal sectional view of a flat vibration motor according to an embodiment of the present invention, FIG. 2 (A) is a plan view of the rotor portion of the flat vibration motor viewed from the back, and (B) is a longitudinal section of the rotor portion. FIG. 3 is an assembly perspective view of the rotor portion.

  The flat vibration motor of the present invention is a brushless motor, and has a plate 11 that supports one end of the support shaft 1 and a circuit board 12 superimposed on the plate 11, and a plurality of air-core coils 13 on the circuit board 12. The electronic part 14 is mounted and the stator part 10 is formed by these.

  In addition, a cover case 20 having a bottomed flat cylindrical shape that supports the other end of the support shaft 1 and a rotor portion 30 that is rotatably supported via a bearing 31 through which the support shaft 1 passes are provided. The opening 20 a of the case 20 is closed by the stator unit 10.

  The rotor portion 30 includes a bearing 31, a rotor frame 32 having a burring portion 32a in which the bearing 31 is fitted, a rotor magnet 33 fixed and fixed to a flat plate portion 32b of the rotor frame 32 with an adhesive, and the like. It consists of an eccentric weight 34 which is fixedly fixed to the flat plate portion 32b with an adhesive or the like on the outside.

  The rotor frame 32 is formed with an outer peripheral portion 32c raised from the flat plate portion 32b in the axial direction, and is in contact with a part of the rotor magnet 33 and the eccentric weight 34. In the flat plate portion 32b and the outer peripheral portion 32c, a part of a contact portion with the eccentric weight 34 is cut out to form a cutout portion 32d, and a part of the eccentric weight 34 is cut out as a protruding portion 34a. Projecting radially outward from 32d.

  The eccentric weight 34 is formed with a stepped portion that abuts the end surface of the cutout portion 32d of the outer peripheral portion 32c of the rotor frame 32 and the inner peripheral surface of the outer peripheral portion 32c as the hooking portion 34b.

  Reference numeral 40 denotes a washer that is passed through the support shaft 1 so as to receive the lower end surface of the bearing 31 and is mounted on the plate 11.

  In such a rotor frame 32 and the eccentric weight 34, the stepped portion 34 b of the eccentric weight 34 abuts against the inner peripheral surface of the outer peripheral portion 32 c of the rotor frame 32 and stops falling off radially outward. Since the protrusion 34a protrudes radially outward from the notch 32d, the eccentric weight 34 can be easily aligned with the rotor frame 32 by the protrusion 34a and the notch 32d. Further, the center of gravity of the eccentric weight 34 is also moved radially outward by the amount of the protruding portion 34a, so that the amount of vibration can be increased. Since the eccentric weight 34 is prevented from falling off radially outward, it is possible to further reinforce the fixing strength of fixing and fixing of the eccentric weight 34 to the rotor frame 32, which is a problem of welding fixation. In fixing fixation of an adhesive or the like that does not cause problems such as corrosion of welded parts, quality variations, and high costs, sufficient fixing strength comparable to welding fixing can be obtained.

  The eccentric weight 34 may be formed with a hooking portion 34c that is a stepped portion that contacts the end surface of the cutout portion 32d of the flat plate portion 32b of the rotor frame 32. The hooking portion 34c can prevent the eccentric weight 34 from falling inward in the radial direction. When combined with the stepped portion 34b, the eccentric weight 34 can be prevented from falling out both inside and outside in the radial direction. It becomes possible to further reinforce the fixing strength of the fixing of the adhesive or the like to the rotor frame 32.

  Alternatively, an arcuate portion 34d may be formed on the side of the spindle 1 of the eccentric weight 34, and the outer peripheral surface of the rotor magnet 33 may be in contact with the arcuate portion 34d. The eccentric weight 34 can be prevented from falling off inward in the radial direction, and the eccentric weight 34 is sandwiched and fixed between the rotor magnet 33 and the outer peripheral portion 32c of the rotor frame 32, so that the radial dropout can be prevented more firmly. Can do.

  4A is a plan view of a rotor portion of a flat vibration motor according to another embodiment of the present invention viewed from the back side, and FIG. 4B is a longitudinal sectional view taken along line aa in FIG. 5 is an assembly perspective view of the rotor portion, and is the same as that of the first embodiment except for the structure of the rotor portion. The same reference numerals are used for parts having the same structure as in the first embodiment, and the description thereof is omitted.

  In the rotor portion 30 ′ of this embodiment, in addition to the structure of the first embodiment, a caulking piece 32 e is formed on the outer peripheral portion 32 c of the rotor frame 32 ′, and the eccentric weight 34 ′ is caulked and fixed.

  In such a rotor frame 32 ′ and the eccentric weight 34 ′, in addition to the effect of preventing the eccentric weight from falling off in the first embodiment, it is possible to prevent the eccentric weight 34 ′ from dropping off in the radial direction by caulking and fixing the shaft. It is possible to prevent the direction from falling off.

  Further, the eccentric weight 34 'may be formed with a recess 34e for receiving the crimping piece 32e. By caulking the caulking piece 32e in the recess 34e, the caulking fixation is more stable.

  Also in the second embodiment, a structure in which an arc-shaped portion 34d is formed on the side of the spindle 1 of the eccentric weight 34 ′ and the outer peripheral surface of the rotor magnet 33 abuts on the arc-shaped portion 34d may be adopted. 'Can be prevented from falling radially inward, and the eccentric weight 34' can be sandwiched and fixed between the rotor magnet 33 and the outer peripheral portion 32c of the rotor frame 32 '.

  In any of the first and second embodiments, the contact surfaces of the rotor magnet 33, the eccentric weight 34 (34 ′), and the outer peripheral portion 32c of the rotor frame 32 (32 ′) may be fixed and fixed with an adhesive or the like. This is possible, and the fixing strength is further improved.

  In the present invention, the structure of the shaft-fixed flat vibration motor has been described, but the present invention can also be applied to a shaft rotation type motor structure.

DESCRIPTION OF SYMBOLS 1 ... Support shaft 10 ... Stator part 11 ... Plate 12 ... Circuit board 13 ... Air core coil 14 ... Electronic component 20 ... Cover case 20a ... Opening part 30, 30 '... Rotor part 31 ... Bearing 32, 32' ... Rotor frame 32a ... Burring part 32b ... Flat plate part 32c ... Peripheral part 32d ... Notch part 32e ... Caulking piece 33 ... Rotor magnets 34, 34 '... Eccentric weight 34a ... Projection part 34b, 34c ... Hook part 34d ... Arc-shaped part 34e ... Recess 40 ... Washer

Claims (6)

A stator portion that supports one end of the support shaft, a cover case that supports the other end of the support shaft with the opening of the cylindrical portion closed by the stator portion, and a bearing through which the support shaft penetrates. And a flat vibration motor comprising a rotor magnet and a rotor frame having an eccentric weight,
The rotor frame has a flat plate portion and an outer peripheral portion that rises in the axial direction from the flat plate portion and contacts a part of the outer peripheral surface of the rotor magnet and the eccentric weight, and the flat plate portion is fixed to the eccentric weight. And a notch part in which a part of the outer peripheral part is notched is formed, and the eccentric weight abuts against the inner peripheral surface of the outer peripheral part to prevent the eccentric part from coming out radially outward, and a part thereof is notched. A hooking portion that protrudes radially outward from the outer peripheral portion and that prevents the eccentric weight from coming off in a radial direction is formed on at least one of the outer peripheral portion or the portion of the eccentric weight that contacts the outer peripheral portion. A flat vibration motor characterized by   2. The flat vibration motor according to claim 1, wherein the hook portion formed on the eccentric weight is a stepped portion that contacts the notch end surface and the inner peripheral surface of the outer peripheral portion of the rotor frame. A flat vibration motor.   3. The flat vibration motor according to claim 1, wherein the eccentric weight is formed with a stepped portion that abuts against a notch end surface of the flat plate portion of the rotor frame. , Flat vibration motor.   4. The flat vibration motor according to claim 1, wherein a caulking piece for fixing the eccentric weight is formed on the rotor frame.   5. The flat vibration motor according to claim 4, wherein the eccentric weight is formed with a recess for receiving the crimping piece.   6. The flat vibration motor according to claim 1, wherein the eccentric weight is formed in an arc shape on the support shaft side, and an outer peripheral surface of the rotor magnet is in contact with the arc-shaped portion. A flat vibration motor.

Images