JP2007229680A - Reciprocating vibration generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating vibration generator which can suppress a maximum displacement of a movable body to one side of an end lid, and therefore can be made thin. <P>SOLUTION: The reciprocating vibration generator is provided with a plate spring 30 formed by integrally connecting three spiral elastic parts 34 between an inner peripheral part 33 and an outer circumferential part 32 surrounding it; a casing body 10 installing the plate spring member 30 by fixing the outer circumferential part 32; a weight 20 mounted on the inner peripheral part 33, having an upper central two-stage protruded part 22 and a collar part 23 separated from the outer circumferential part 32 of the plate spring 30 via a space S; and an exciting coil 70 vertically and reciprocatingly vibrating the weight 20 by magnetic attraction or magnetic repulsion with respect to a permanent magnet 60. At trisected points of a circumference of an opposing face 23a facing the outer circumferential part 32, of the collar 23, collision mitigating elastic bodies 90 having hemispherical heads 92 facing root parts 35 of the spiral elastic parts 34 are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reciprocating vibration generator mounted on a mobile phone or the like.

Conventionally, as a reciprocating vibration generator for generating sound generation or vibration, as shown in JP-T-2003-515435, an end cover that closes the opening of the case body is made to function as a sound generation plate. The outer peripheral part of the leaf spring is fixed with the case body, the central part of the movable body consisting of the permanent magnet and the yoke is attached to the central part of the leaf spring, and between the center of the leaf spring and the center of the movable body There is known a structure in which an elastic body is sandwiched and a movable body is suspended and supported by a leaf spring via the elastic body. In the sound generation mode in which the end lid vibrates and generates sound, the elastic body absorbs the vibration frequency having a high sound frequency, so that the vibration of the movable body can be suppressed.
Special Table 2003-515435 (FIG. 1B)

  However, since the movable body is supported by a series connection of a leaf spring and an elastic body with respect to the case body, in the vibration mode in which the movable body reciprocally vibrates, the amplitude of the movable body is increased by the expansion / contraction displacement of the elastic body. There is a possibility that the central portion of the movable body or the leaf spring may collide with the end cover as the sound generation plate. For this reason, the distance between the leaf spring and the end lid needs to be relatively large, which is an obstacle to reducing the thickness of the reciprocating vibration generator.

  Therefore, in view of the above problems, an object of the present invention is to provide a reciprocating vibration generator that can suppress the maximum displacement of one end of a movable body to one side, such as an end cover, and can achieve a reduction in thickness.

  In order to solve the above problems, the present invention provides a spring member formed by integrally connecting a plurality of spiral elastic portions between a central portion and an outer peripheral portion surrounding the central portion, and fixing the outer peripheral portion to A case main body for laying a spring member; a central attachment portion attached to a central portion of the spring member; a movable body having a peripheral portion spaced from the outer peripheral portion side of the spring member via a gap; A reciprocating vibration generator comprising an exciting coil for reciprocating vibration of the movable body in the vertical direction by magnetic attraction or magnetic repulsion with respect to a magnetic generator constituting a part of the spring member, A collision buffering elastic body is provided at each of the equidistant points in the circumferential direction of the facing surface facing the outer peripheral side. Here, the “spiral shape” means not only a two-dimensional spiral shape on a flat plate but also a three-dimensional spiral shape extending in the axial direction of the winding center axis.

  In such a configuration, for example, when the spring member bends and expands to one side such as an end cover, the amount of bending of the spring member is large at the center, and gradually increases from the center to the fixed end at the outer periphery. However, since the entire movable body is translated and displaced to one side of the end cover etc. according to the amount of bending of the central part of the spring member, the impact buffering elastic body around the movable body is moved to the outer peripheral side of the spring member. In this period, the movable body is supported in parallel connection by the spring member and the impact buffering elastic body with respect to the case main body during the period from the start to the end. For this reason, the inertial force in one direction of the movable body is dispersed, and a part of the inertial force gradually acts on the outer peripheral side of the spring member via the impact buffering elastic body, so that the central attachment portion of the movable body The bending moment acting on the central part of the spring member gradually decreases, self-braking acts on the swelling of the central part of the spring member toward the end cover, and the maximum displacement of the end cover on one side is suppressed, so that the center of the movable body It is possible to prevent the contact portion or the central portion of the spring member from hitting the end cover or the like, and to realize a thin reciprocating vibration generator.

  Conversely, when the spring member stops instantaneously with maximum deflection to one side, such as an end cap, and then returns and deforms to the other side, the elastic energy accumulated in the impact buffering elastic body is released and a strong restoring force is released. Acts directly on the periphery of the movable body, so that the acceleration of the movable body increases before and after the maximum bending state of the spring member, so that strong vibration can be obtained.

  Furthermore, since the thing which hits the outer peripheral part side of a spring member is the elastic body for collision buffering, generation | occurrence | production of abnormal noise can be suppressed.

  In addition, since the impact buffering elastic body is provided on the peripheral side of the movable body, it is easier to manufacture and the impact buffering elasticity than when the impact buffering elastic body is provided on the outer peripheral side of the spring member. The weight of the body is superimposed on the movable body as a weight. Of course, if conditions permit, a collision buffering elastic body may be provided on the spring member or the case body.

  Here, in some cases, the exposed portion of the outer periphery of the spring member from the case main body cannot be sufficiently secured in view of the size of the impact buffering elastic body, so the position of the head of the impact buffering elastic body is spiral elastic. It is preferable that the portion face the root portion extending from the outer peripheral portion. A sufficient contact area can be ensured by a part of the outer peripheral portion and the base portion. In addition, when the impact buffering head is compressed, the lateral distortion causes the contact portion to expand from the root portion to the spiral elastic portion side, so the effect of shortening the length of the spiral elastic portion and increasing the elastic modulus is also effective. Therefore, the maximum displacement of the spring member can be further suppressed.

  When the impact buffering elastic body is plate-shaped, an adhesion process to the movable body is required, and since the contact with the outer peripheral portion side of the spring member is surface contact, there is still a possibility that abnormal noise may be generated. Furthermore, there is almost no transverse distortion effect. Therefore, as the impact buffering elastic body, an integrally formed product of a shaft portion and a cap-shaped head portion that are press-fitted into a hole formed in the facing surface is desirable. The impact buffering elastic body can be attached simply by press-fitting the shaft part into the hole in the peripheral part, and the head is capped so that it does not come out and the bonding process can be eliminated. In addition, the contact with the outer peripheral side of the spring member starts from the apex of the cap-shaped head, and the contact range gradually expands therefrom, so that the generation of abnormal noise can be prevented. It is desirable that the head portion is a hemisphere.

  According to the reciprocating vibration generator according to the present invention, it is possible to suppress the maximum displacement of the movable body on one side, such as the end cover, and to realize a reduction in thickness.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is an exploded perspective view showing a reciprocating vibration generator according to an embodiment of the present invention, FIG. 2A is a plan view showing the reciprocating vibration generator, and FIG. 2B is b in FIG. 2A. FIG. 3A is a cross-sectional view taken along the line aa in FIG. 2A, and FIG. 3B is a cross-sectional view taken along the line bb in FIG. 3A. It is sectional drawing cut | disconnected.

  The reciprocating vibration generator of this example includes a resin-made cylindrical case body 10 and a heavy metal weight 20 suspended in the hollow so that an outer peripheral protrusion 31 is formed in the inner peripheral groove 11 near the upper opening of the case body 10. An annular permanent magnet 60 attached to the lower central projection 21 of the weight 20 sandwiched between the inserted and fixed leaf spring 30, the upper outer yoke 40 and the lower inner yoke 50, and the permanent magnet 60 A cylindrical air core toroidal coil 70 for reciprocally vibrating the movable body including the weight 20 in the vertical direction by magnetic attraction or magnetic repulsion is placed, and a bottom lid (bottom cover) for closing the lower opening of the case body 10 A case) 80 and a resin upper lid (top case) 85 for closing the upper opening of the case body 10.

  The leaf spring 30 includes an annular outer peripheral portion 32 having a plurality of outer peripheral protruding piece portions 31, a central annular inner peripheral portion 33 for attaching the upper center two-step protruding portion 22 of the weight 20, and a circle as a fixed end. It comprises a three-piece spiral elastic portion 34 that integrally connects an annular outer peripheral portion 32 and an annular inner peripheral portion 33 as a free end. Adjacent ones of the spiral elastic portions 34 are of such a length that the central angle is about 180 ° and there is no opposing portion in order to increase the elastic coefficient.

  The outer yoke 40 has a central hole that fits into the lower central projection 21 and is in close contact with the flange 23 of the weight 20, and an outer peripheral side of the air-core toroidal coil 70 that is bent from the outer peripheral side to the lower side. And a falling portion 42 that reaches. The upper surface of the annular permanent magnet 60 is in close contact with the substrate portion 41 as a back yoke, and the lower surface of the annular permanent magnet 60 is in close contact with the upper surface of the inner yoke 50 as a front yoke. The falling part 42 of the outer yoke 40 reciprocates up and down in an annular space between the inner peripheral surface of the case body 10 and the outer peripheral surface of the air core toroidal coil 70, and the magnetic flux generated by the annular permanent magnet 60 and the air core toroid. In order to collect the magnetic flux on the outer peripheral side of the coil 70, the leakage magnetic flux outside the case body 10 is prevented. The bottom cover 80 is an insert-molded plate in which three terminal plates are insulated and separated by a mold resin, and includes a terminal block 81.

  As shown in FIG. 1 and FIG. 3, in the weight 20, at the circumferential equally divided point of the upper surface (opposite surface) 23 a of the flange portion 23 facing the outer peripheral portion 32 side of the leaf spring 30 through the annular gap S. Is provided with a small hole h. Each small hole h is press-fitted with a shaft portion 91 of a mushroom-shaped impact buffering elastic body 90, which is an integrally molded product made of a viscoelastic material, and the hemispherical head portion 92 projects from the upper surface 23a to the leaf spring 30 side. Yes. The position of the hemispherical head 92 faces the root portion 35 where the spiral elastic portion 34 of the leaf spring 30 extends from the outer peripheral portion 32.

  An alternating current is applied to the exciting coil 70 to reciprocally vibrate the movable body composed of the weight 20, the permanent magnet 60, and the yokes 40, 50. When the leaf spring 30 is bent and expands toward the upper lid 85, the leaf spring 30 is expanded. The amount of bending of the inner peripheral portion 33 is larger, and the amount of bending gradually decreases as the inner peripheral portion 33 moves from there to the fixed end of the outer peripheral portion 32. Accordingly, the hemispherical head portion 92 of the impact buffering elastic body 90 of the flange portion 23 of the weight 20 hits the base portion 35 of the leaf spring 30, and from the beginning to the end, the contact ends. Until this time, the weight 20 is supported by the leaf spring 30 and the collision buffering elastic body 90 in parallel connection with the case body 10. For this reason, the inertial force toward the upper lid 85 side of the weight 20 is dispersed, and a part of the inertial force acts on the base portion 35 side of the leaf spring 30 through the impact buffering elastic body 90, so that the leaf spring 30 is increased. The bending moment acting on the inner peripheral portion 33 gradually decreases, self-braking acts on the bulge of the leaf spring 30 toward the upper lid 85 side, and the maximum displacement toward the upper lid 85 side is suppressed. Therefore, it is possible to reduce the thickness of the reciprocating vibration generator.

  Conversely, when the leaf spring 30 stops instantaneously with the maximum deflection toward the upper lid 85 and then returns to the bottom lid 80 and deforms, the elasticity accumulated in the hemispherical head 92 of the impact buffering elastic body 90 is obtained. Since the energy is released and a strong restoring force directly acts on the flange 23, the acceleration of the movable body before and after the maximum bending state of the leaf spring 30 is increased, so that strong vibration can be obtained.

  Furthermore, since what hits the base portion 35 of the leaf spring 30 is the hemispherical head portion 92 of the collision buffering elastic body 90, the generation of abnormal noise can be suppressed. In particular, since a viscoelastic material is used as the elastic material, it can be quieter than rubber.

  In addition, since the impact buffering elastic body 90 is provided on the flange portion 23 of the weight 20, it is easier to manufacture than the case where the impact buffering elastic body 90 is provided at the base portion 35 of the leaf spring 30. The weight of the buffering elastic body 90 is superimposed as a weight.

  The impact buffering elastic body may be provided so as to hit only the outer peripheral portion 32 by changing the size and number of the elastic bodies, or may be provided so as to straddle the middle of the spiral elastic portion 34. it can.

  When the hemispherical head 92 is compressed, the contact portion expands from the root portion 35 toward the spiral elastic portion 34 due to the lateral strain, and therefore the length of the spiral elastic portion 34 is slightly shortened. This increases the effect of suppressing the maximum displacement of the leaf spring 30.

  When the mushroom-like collision buffering elastic body 90 is used, the point of contact becomes point contact, and the contact range gradually increases from that point. Moreover, it can be attached simply by press-fitting the shaft portion 91 into the small hole h, and since the head portion 92 is capped, it does not come off and the bonding step can be eliminated.

It is a disassembled perspective view which shows the reciprocating vibration generator of the Example which concerns on this invention. (A) is a top view which shows the reciprocating vibration generator, (B) is sectional drawing cut | disconnected by the bb line in (A). (A) is sectional drawing cut | disconnected by the aa line in FIG. 2 (A), (B) is sectional drawing cut | disconnected by the bb line in (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Cylindrical case main body 11 ... Inner peripheral groove | channel 20 ... Weight 21 ... Lower side center protrusion 22 ... Upper center center 2 step protrusion 23 ... ridge part 23a ... Upper surface (opposite surface)
DESCRIPTION OF SYMBOLS 30 ... Plate spring 31 ... Outer peripheral protrusion part 32 ... Annular outer peripheral part 33 ... Annular inner peripheral part 34 ... Spiral elastic part 35 ... Base part 40 ... Outer yoke 41 ... Substrate part 42 ... Falling part 50 ... Inner yoke 60 ... Permanent magnet 70 ... Air core toroidal coil 80 ... Bottom cover (bottom case)
81 ... Terminal block 85 ... Top cover (top case)
90 ... Collision buffer elastic body 91 ... Shaft portion 92 ... Hemispherical head h ... Small hole S ... Air gap

Claims (4)

A spring member formed by integrally connecting a plurality of spiral elastic portions between a central portion and an outer peripheral portion surrounding the central portion; a case main body for fixing the outer peripheral portion and installing the spring member; and the spring A movable body having a central attachment portion attached to the central portion of the member and a peripheral portion separated from the outer peripheral portion side of the spring member via a gap, and magnetic attraction to a magnetic generator constituting a part of the movable body Or a reciprocating vibration generator comprising an excitation coil for reciprocating the movable body in the vertical direction by magnetic repulsion,
A reciprocating vibration generator, characterized in that a collision buffering elastic body is provided at each circumferentially equally dividing point of the opposing surface facing the outer peripheral portion side of the spring member in the peripheral portion. 2. The reciprocating vibration generator according to claim 1, wherein a head portion of the elastic body for impact buffering faces a root portion where the spiral elastic portion extends from the outer peripheral portion. 3. The reciprocating vibration generator according to claim 1, wherein the collision buffering elastic body is an integrally formed product of a shaft portion and a cap-shaped head portion that are press-fitted into a hole formed in the facing surface. A reciprocating vibration generator. The reciprocating vibration generator according to any one of claims 1 to 3, wherein the cap-shaped head is substantially a hemispherical body.

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