WO2006109350A1 - Eccentric weight, vibration motor, and portable apparatus - Google Patents

Abstract

An eccentric weight (120) is constructed by integrating a weight (140) and a weight support body (130). The weight section (140) is made from metal having high specific gravity. The weight support body (130) a has a weight holding section (134) for holding the weight (140) and a motor shaft holding section (132) for holding a motor shaft, and is formed from a metallic elastic body having a specific gravity lower than that of the high specific gravity metal that forms the weight (140). The weight holding section (134) has a weight side projection section (135) whose amount of projection to the weight (140) side is reduced when the weight (140) and the weight support body (130) are integrated. The total weight the eccentric weight (120) can be reduced and the amount of eccentricity of the eccentric weight (120) can be increased. Further, even when the eccentric weight (120) is used for long hours, reduction in reliability of the joint between the weight (140) and the weight support body (130) is suppressed.

Description

 Specification

 Eccentric weight, vibration motor and portable device

 Technical field

 The present invention relates to an eccentric weight, a vibration motor, and a portable device.

 Background art

 In mobile phones and PDAs, vibration motors are used to notify incoming calls by vibration. FIG. 15 is a diagram for explaining a conventional vibration motor and an eccentric weight. Fig. 15 (a) is a perspective view of the vibration motor, Fig. 15 (b) is a cross-sectional view of the eccentric weight cut along a plane perpendicular to the motor axis, and Fig. 15 (c) is an eccentric weight along the motor axis. FIG. In FIGS. 15 (b) and 15 (c), the position of the eccentric weight in FIG. 15 (a) in the rotational direction is changed.

 [0003] As shown in FIG. 15, a conventional vibration motor 1100 includes a small cylindrical motor body 1110 and an eccentric weight 1120 made of a sintered body of tungsten or the like and having a substantially fan shape. The motor shaft 1112 force S of the motor body 1110 is held in the motor shaft holding hole 1122 of the eccentric weight 1120. Eccentric weight 1120 is attached to the tip of motor shaft 1112 by tightening by deforming motor shaft holding hole 1122 by applying external force from the thin side surface of motor shaft holding hole 1 122 through which motor shaft 1112 passes. (For example, see Patent Document 1).

 [0004] By the way, in a mobile phone, a PDA, and the like, a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption is required as a vibration motor. For this reason, another eccentric weight as shown in FIG. 16 has been proposed as an eccentric weight used in such a vibration motor. FIG. 16 is a diagram for explaining another conventional eccentric weight. Fig. 16 (a) is a front view of the eccentric weight, Fig. 16 (b) is a cross-sectional view taken along the line A_A in Fig. 16 (a), Fig. 16 (c) is a front view of the component, and Fig. 16 (d ) Is a cross-sectional view taken along line BB in FIG. 16 (c). In FIG. 16 (a) and FIG. 16 (b), a part of the motor body 1210 is also shown.

[0005] As shown in Fig. 16, another conventional eccentric weight 1220 has a motor shaft holding hole 1232 for holding the motor shaft 1212 of the motor body 1210, and has a cylindrical portion made of a low specific gravity metal. It consists of a copper support 1230 and a substantially half-pipe weight 1240 made of a high specific gravity metal (see, for example, Patent Document 1). For this reason, since the weight 1240 is made of a high specific gravity metal, the center of gravity of the eccentric weight 1220 is arranged at a position separated from the center axis of the motor shaft holding hole 1232. As a result, the amount of eccentricity in the eccentric weight 1220 increases, and by using such other conventional eccentric weight 1220, a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption can be configured.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-129479

 Disclosure of the invention

 Problems to be solved by the invention

 However, in the above-described other conventional eccentric weight 1220, the weight 1240 is integrally bonded and fixed to a part of the outer surface 1234 of the weight support 1230 via the brazing portion 1250. Therefore, when the vibration motor (and the eccentric weight) is used for a long time, there is a problem that the reliability of the connection between the weight and the weight support is lowered.

 Therefore, the present invention has been made to solve such a problem, and can be suitably used for a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption. An object of the present invention is to provide an eccentric weight which is a weight and in which the reliability of bonding between the weight and the weight support is suppressed even when such a vibration motor is used for a long time. Another object of the present invention is to provide a vibration motor and a portable device having such an excellent eccentric weight.

 Means for solving the problem

 [0009] (1) The eccentric weight of the present invention includes a weight made of a high specific gravity metal, a weight holding portion for holding the weight, and a motor shaft holding portion for holding the motor shaft. An eccentric weight manufactured by integrating a weight support made of an elastic body made of a metal having a specific gravity lower than that of a high specific gravity metal, wherein the weight holding portion includes the weight and the weight support. And a weight side protruding portion that reduces the amount of protrusion to the weight side when integrated.

[0010] Therefore, according to the eccentric weight described in (1) above, the eccentric weight includes a weight made of a high specific gravity metal, and a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight. The Since the eccentric weight is manufactured by integrating, the total weight of the eccentric weight can be reduced and the amount of eccentricity in the eccentric weight can be increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption.

[0011] Further, according to the eccentric weight described in (1) above, since the weight support is a weight support made of an elastic body, the weight is held by the weight holding portion by the elastic force of the entire weight holding portion. It will be. For this reason, when the vibration motor (and eccentric weight) is used for a long time, the reliability of the connection between the weight and the weight support is suppressed, and by using such an eccentric weight, long-term reliability is ensured. A high vibration motor can be configured.

 [0012] In addition, according to the eccentric weight described in (1), the weight holding portion has a weight side protrusion that reduces the amount of protrusion to the weight side when the weight and the weight support are integrated. Since the weight holding portion is used, the weight is held by the weight holding portion with a stronger elastic force to which the elastic force of the weight side protruding portion is added. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, the reliability of the connection between the weight and the weight support is further suppressed, so by using such an eccentric weight, It is possible to construct a vibration motor with higher long-term reliability.

 [0013] According to the eccentric weight described in (1) above, since the weight support body is a weight support body made of an elastic body, the motor shaft is held by the motor shaft holding portion by elastic force. . For this reason, when the vibration motor is used for a long time, it is suppressed that the reliability of the connection between the motor shaft and the weight support is lowered, and a vibration motor with high long-term reliability can be configured.

[0014] In the eccentric weight described in (1) above, the size of the inner peripheral portion of the weight holding portion before integrating the weight and the weight support is smaller than the size of the outer peripheral portion of the weight. Is preferable. As a result, the weight is inserted into the weight holding portion in a state where the inner peripheral portion is expanded, whereby the weight is held by the weight holding portion by the elastic force of the entire weight holding portion.

[0015] In the eccentric weight described in (1) above, it is preferable that the inner diameter of the motor shaft holding portion is smaller than the outer diameter of the motor shaft. As a result, when the vibration motor is assembled using the eccentric weight described in (1) above, the motor shaft holding member whose inner diameter is once expanded is used. By inserting the motor shaft into the holding portion, the motor shaft after insertion is held in the motor shaft holding portion by elastic force.

 [0016] In the eccentric weight of the present invention, "integrating the weight and the weight support" includes all bonding of the weight and the weight support by some method.

 (2) In the eccentric weight described in the above (1), the weight side protruding portion has a small amount of protrusion to the weight side as the weight is inserted into the weight holding portion. It is preferable to have such a structure.

 With this configuration, as the weight is inserted into the weight holding portion, the weight gradually pushes the weight side protruding portion outward. For this reason, the operation of inserting the weight into the weight holding portion is facilitated, and the manufacturing cost for manufacturing the eccentric weight can be reduced.

 [0019] (3) In the eccentric weight described in (1) or (2), the motor shaft holding portion protrudes toward the motor shaft when the motor shaft is inserted into the motor shaft holding portion. It is preferable to have a motor shaft side protrusion that reduces the amount.

 With this configuration, the motor shaft is held by the motor shaft holding portion with a stronger elastic force to which the elastic force of the motor shaft side protruding portion is added. For this reason, when the vibration motor is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the motor shaft and the weight support, and thus a vibration motor with high long-term reliability can be configured.

 (4) The eccentric weight described in (3) above, and the motor shaft side protruding portion moves toward the motor shaft side as the motor shaft is inserted into the motor shaft holding portion. It is preferable to have a structure in which the amount of protrusion of the film becomes smaller.

 With this configuration, as the motor shaft is inserted into the motor shaft holding portion, the motor shaft gradually pushes the motor shaft side protruding portion outward. For this reason, the operation of inserting the motor shaft into the motor shaft holding portion is facilitated, and the manufacturing cost when manufacturing the vibration motor using this eccentric weight can be reduced.

[0023] (5) The eccentric weight of the present invention includes a weight made of a high specific gravity metal, a weight holding portion for holding the weight, and a motor shaft holding portion for holding the motor shaft. Integrates a weight support made of an elastic body of a metal with a specific gravity lower than that of the high specific gravity metal The weight support body has a structure in which the weight holding portion holds the weight with a stronger elastic force when the motor shaft is inserted into the motor shaft holding portion. It is characterized by having.

 [0024] Therefore, according to the eccentric weight described in (5) above, the eccentric weight includes a weight made of a high specific gravity metal, and a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight. Since the eccentric weight is manufactured by integrating the two, the total weight of the eccentric weight can be reduced and the amount of eccentricity in the eccentric weight can be increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption.

 [0025] According to the eccentric weight described in (5) above, since the weight support is a weight support made of an elastic body, the weight is held by the weight holding portion by an elastic force. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight and the weight support, and by using such an eccentric weight, long-term reliability can be improved. A high and vibration motor can be configured.

 [0026] Further, according to the eccentric weight described in (5) above, when the weight support is inserted into the motor shaft holding portion, the weight holding portion holds the weight with a stronger elastic force. Since the weight support body has a simple structure, the weight is held by the weight holding portion with a stronger elastic force when the motor shaft is inserted into the motor shaft holding portion. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, the reliability of the connection between the weight and the weight support is further suppressed, so by using such an eccentric weight, A vibration motor with higher long-term reliability can be configured.

 (6) The eccentric weight of the present invention includes a weight made of a high specific gravity metal, a weight holding portion for holding the weight, and a motor shaft holding portion for holding the motor shaft, An eccentric weight manufactured by integrating a weight support made of an elastic body made of a metal having a specific gravity lower than that of a high specific gravity metal, wherein the weight support includes the weight and the weight support. When the motor is integrated, the motor shaft holding part has a structure that allows the space defined by the motor shaft holding part to be reduced.

[0028] Therefore, according to the eccentric weight described in the above (6), the eccentric weight is made of a high specific gravity metal. An eccentric weight manufactured by integrating a weight and a weight support made of a metal having a specific gravity lower than that of the high-density metal that constitutes the weight, thereby reducing the total weight of the eccentric weight and reducing the eccentric weight in the eccentric weight. The amount can be increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption.

 [0029] Further, according to the eccentric weight described in (6) above, since the weight support body is a weight support body made of an elastic body, the weight is held by the weight holding portion by elastic force. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight and the weight support, and by using such an eccentric weight, long-term reliability can be improved. A high and vibration motor can be configured.

 [0030] Further, according to the eccentric weight described in the above (6), when the weight support is integrated with the weight and the weight support, a structure in which the space defined by the motor shaft holding portion is reduced. Since the weight support is provided, the motor shaft is held by the motor shaft holding portion with a stronger elastic force when the weight and the weight support are integrated. For this reason, when the vibration motor is used for a long period of time, it is further suppressed that the reliability of the connection between the motor shaft and the weight support is reduced, so that a vibration motor with higher long-term reliability can be configured. .

 [0031] (7) In the eccentric weight described in (1) to (6) above, the weight support is subjected to a hardening treatment after plastic deformation of the thin metal member into a predetermined shape. It is preferably made of an elastic body manufactured by

 [0032] With this configuration, the amount of the material constituting the weight support can be made extremely small while maintaining the required strength. As a result, the total weight of the eccentric weight can be reduced and the amount of eccentricity in the eccentric weight can be further increased. For this reason, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

 (8) It is preferable that the eccentric weight described in (7) above has a picker hardness (Hv) of 150 or more.

With this configuration, the weight support body can hold the weight with a strong elastic force and can hold the motor shaft with a strong elastic force. From this point of view In other words, the Vickers hardness (Hv) of the weight support is more preferably 200 or more, and further preferably 250 or more.

 [0035] (9) In the eccentric weight described in (7) or (8) above, it is preferable that the thin metal member is made of a metal having quench hardening properties.

 [0036] With this configuration, a weight support can be easily manufactured by performing a quenching process after plastically deforming a thin metal member into a predetermined shape.

 [0037] (10) In the eccentric weight described in (9) above, the quench-hardening metal is preferably martensitic stainless steel.

 [0038] In general, a material constituting a weight (for example, tungsten, tungsten alloy, etc.) has a low corrosion resistance and tends to crack. Therefore, the eccentric weight as a whole has a high corrosion resistance and is difficult to crack (for example, nickel. ). However, when plastic caulking or the like is applied after the plating, the joint between the eccentric weight and the plating film and the plating film itself are easily cracked. It tends to occur. For this reason, there was a problem that the reliability related to the holding of the motor shaft in the motor shaft holding portion was reduced. On the other hand, martensitic stainless steel is originally a material that has high corrosion resistance and is difficult to crack, so it is not necessary to apply a plating. For this reason, the joint portion between the eccentric weight and the plating film and the plating itself are not cracked, and the reduction in the reliability of the motor shaft holding portion regarding the holding of the motor shaft is suppressed.

 [0039] In addition, since materials (for example, tungsten and tungsten alloys) constituting weights are generally brittle, there is a problem that they are easily broken. On the other hand, martensitic stainless steel is more viscous than tungsten, tungsten alloys, etc., so by holding such a brittle and fragile weight with martensitic stainless steel, the material constituting the weight If it is easy to break, the problem of cracking is also suppressed.

[0040] Further, since materials (for example, tungsten and tungsten alloys) constituting weights are generally expensive, there is a problem that it is not easy to reduce the manufacturing cost of the eccentric weight. On the other hand, martensitic stainless steel is less expensive than tungsten and tungsten alloys. Therefore, by constructing a weight support with such a relatively inexpensive martensitic stainless steel, the manufacture of eccentric weight is possible. Possible to reduce costs Become.

 [0041] It should be noted that, as the manure sugar beet type stainless steel maoka, it is possible to display SUS403, SUS410, SUS416, S US420, SUS429, SUS431, SUS440 and the like.

 In this case, the quenching process gives a value of about 300-600 as the Vickers hardness (Ην).

 [0042] (11) In the eccentric weight described in (7) or (8) above, the thin metal member is preferably made of a metal having age hardening.

 [0043] With this configuration, a weight support can be easily manufactured by subjecting a thin metal member to plastic deformation after being plastically deformed into a predetermined shape, followed by precipitation hardening.

 (12) In the eccentric weight described in (11) above, the age-hardening metal is precipitation hardened stainless steel, beryllium copper alloy, nickel manganese copper alloy or precipitation hardened titanium alloy. Is preferred.

 [0045] When the age-hardening metal is a precipitation hardening stainless steel, substantially the same effect as in the case of the martensitic stainless steel described in (9) above is obtained, and the martensitic stainless steel is obtained. The effect that it is excellent in corrosion resistance than the case of steel is acquired. Examples of precipitation hardening stainless steel include SUS630 and SUS631. In this case, a Vickers hardness (Hv) of about 300-450 is obtained by precipitation hardening for 2 hours at 420 ° C.

 [0046] When the age-hardening metal is a beryllium copper alloy, the effects of easy plastic deformation and excellent mechanical strength after precipitation hardening are obtained. Examples of the beryllium copper alloy include beryllium copper alloys containing 0.8% to 4.0% (more preferably 1.5% to 3.5%) of beryllium. In this case, a value of 200 to 350 as the Vickers hardness (Hv) can be obtained by precipitation hardening for 2 hours at 320 to 330 ° C.

[0047] Even when the age-hardening metal is Nikkenore Manganese Copper Alloy (Nickel Manganese Yoro), the effect of easy plastic deformation and excellent mechanical strength after precipitation hardening is obtained. An example of the nickel manganese copper alloy is a nickel manganese copper alloy containing about 20% nickel and about 20% manganese, with the balance being copper. In this case, a precipitation hardening treatment at 400 ° C for 2 hours gave a Vickers hardness (Hv) of about 420. It is.

 [0048] Even when the age-hardening metal is a precipitation hardening titanium alloy, the effects of easy plastic deformation and excellent mechanical strength after precipitation hardening can be obtained. Precipitation hardening titanium alloys have a relatively low specific gravity, so that the total weight of the weight support can be further reduced, and the amount of eccentricity in the eccentric weight can be further increased. For this reason, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter weight and less power consumption. Low specific gravity precipitation hardened titanium alloys include titanium alloys containing about 6% aluminum and about 4% vanadium (Ti_6Al_4V) and titanium alloys containing about 6% aluminum and about 2% vanadium (Ti-6A1-2V) ) Is exemplified. In this case, a value of about 300 Vickers hardness (Hv) can be obtained by precipitation hardening for 2 hours at 450 ° C.

 [0049] (13) In the eccentric weight described in any of (7) to (: 12) above, the thickness of the thin metal member may be in the range of 0.05 mm to 0.5 mm. preferable.

 [0050] That is, if the thickness of the thin metal member is less than 0.05 mm, the strength required for the weight support may not be obtained. If the thickness of the thin metal member exceeds 0.5 mm, This is because the effect of reducing the total weight of the weight support and further increasing the amount of eccentricity in the eccentric weight may not be obtained. From these viewpoints, the thickness of the thin metal member is more preferably in the range of 0.08 mm to 0.3 mm.

 [0051] (14) In the eccentric weight described in any of (7) to (13) above, it is preferable that a predetermined opening is provided in the thin metal member.

 [0052] With this configuration, the amount of the material constituting the weight support can be further reduced while maintaining the required strength. As a result, the total weight of the eccentric weight can be further reduced, and the amount of eccentricity in the eccentric weight can be further increased. For this reason, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

[0053] (15) In the eccentric weight according to any one of the above (1) to (: 14), the weight is selected from the group consisting of tandasten, tungsten alloy, osmium, osmium alloy, gold, gold alloy, iridium or iridium alloy. It is preferable to consist of. [0054] By configuring in this way, tungsten, tungsten alloy, sumidium, osmium alloy, gold, gold alloy, iridium or iridium alloy has a very high specific gravity, so that the amount of eccentricity in the eccentric weight can be further increased. it can. For this reason, by using such an eccentric weight, it is possible to construct a vibration motor that can obtain the required amount of vibration with less power consumption.

 [0055] In the eccentric weight of the present invention, since the weight does not need a function for holding the motor shaft, the weight has a very simple shape (for example, a cross-section such as a circle, an ellipse, or a sector). Can be adopted. For this reason, as a weight, a sintered body sintered in the shape of a weight, or a sintered body with a deformed bar force having the same cross-sectional shape as a weight (for example, a circle, an ellipse, a fan shape, etc.) is cut short. You can use what you have done. It is also possible to use a cutting body that has been cut into a short cross-sectional shape that is the same as the cross-sectional shape of the weight by cutting a sintered body having a round bar force. In addition, when the cross-sectional shape of the weight is a circle, a sintered body made of a round bar can be used as it is cut short.

[0056] (16) In the eccentric weight according to any one of (1) to (15), it is preferable that the weight is held in the weight holding portion over a half circumference.

By configuring in this way, it is further suppressed that the reliability of bonding between the weight and the weight support is lowered when the vibration motor is used for a long time.

[0058] In this case, "half or more" means more than half of the entire circumference of the weight on a plane perpendicular to the longitudinal direction of the weight (ie, a plane perpendicular to the motor shaft). The weight may be held in the weight holding portion over the entire length of the weight, but it is not necessarily required to be held in the weight holding portion over the entire length of the weight.

 [0059] (17) In the eccentric weight according to any one of (1) to (: 16), the weight support is a weight that holds the weight from one side or both sides in a direction along the motor shaft. It is preferable to have a holding frame.

By configuring in this way, the weight support can hold the weight from one side or both sides in the direction along the motor shaft. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, the reliability of the connection between the weight and the weight support decreases. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor with higher reliability and long-term reliability.

 (18) In the eccentric weight according to any one of (1) to (17), the weight is a plane having a predetermined first plane including the central axis of the motor shaft holding portion as a symmetry plane. It preferably has a symmetrical shape.

 [0062] With this configuration, the weight can be inserted into the weight holding part from any end side, so that the degree of freedom in placing the weight in the weight holding part is increased, and the work is performed. Improves. For this reason, the manufacturing cost at the time of manufacturing an eccentric weight can be made low.

 [0063] In the eccentric weight described in (18) above, "the central axis of the motor shaft holding portion" is an axis on which the central axis of the motor shaft is located when the motor shaft holding portion holds the motor shaft That is.

 [0064] (19) A vibration motor of the present invention includes a motor body and the eccentric weight according to any one of (1) to (18).

 Therefore, as described above, the vibration motor of the present invention is an eccentric weight that can be suitably used for a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption. Because it is equipped with an excellent eccentric weight that suppresses the decrease in the reliability of the connection between the weight and the weight support when the vibration motor is used for a long time, the required amount of vibration is reduced with light weight and low power consumption. The vibration motor is obtained with high reliability for a long time.

 [0066] (20) In the vibration motor according to (19), the weight holding portion in which a length of the weight holding portion along a longitudinal direction of the weight is shorter than the weight is used as the eccentric weight. An eccentric weight for holding the weight at an eccentric position along the longitudinal direction of the weight is provided, and the eccentric weight is closer to the motor body in a direction in which the distance between the motor shaft holding portion and the motor body is closer. It is preferable to be fixed to.

 With this configuration, the distance between the motor shaft holding portion of the eccentric weight and the bearing of the motor main body is reduced, so that the deflection of the motor shaft is suppressed when the motor shaft rotates. As a result, the eccentric weight rotates more stably and the eccentric vibration characteristics of the vibration motor are improved.

(21) A portable device of the present invention includes the vibration motor according to (19) or (20). Features.

 [0069] For this reason, according to the portable device of the present invention, a necessary amount of vibration can be obtained with light weight and low power consumption, and since a highly reliable vibration motor is provided for a long time, light weight and low power consumption are required. A large amount of vibration can be obtained, and the portable device is highly reliable for a long time.

 Brief Description of Drawings

 [0070] FIG. 1 is a view for explaining an eccentric weight according to a first embodiment.

 FIG. 2 is a view for explaining the manufacturing method of the eccentric weight according to the first embodiment.

 FIG. 3 is a view for explaining the vibration motor according to the first embodiment.

 FIG. 4 is a view for explaining an eccentric weight according to the second embodiment.

 FIG. 5 is a view for explaining an eccentric weight according to the third embodiment.

 FIG. 6 is a view for explaining an eccentric weight according to the fourth embodiment.

 FIG. 7 is a view for explaining an eccentric weight according to the fifth embodiment.

 FIG. 8 is a perspective view of an eccentric weight according to a sixth embodiment.

 FIG. 9 is a view for explaining an eccentric weight according to the seventh embodiment.

 FIG. 10 is a view for explaining an eccentric weight according to an eighth embodiment.

 FIG. 11 is a view for explaining an eccentric weight according to the ninth embodiment.

 FIG. 12 is a view for explaining the manufacturing method for the eccentric weight according to the ninth embodiment.

 FIG. 13 is a view for explaining the vibration motor according to the ninth embodiment.

 FIG. 14 is a view for explaining an eccentric weight according to the tenth embodiment.

 FIG. 15 is a view for explaining a conventional vibration motor and an eccentric weight.

 FIG. 16 is a view for explaining another conventional eccentric weight.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the eccentric weight, vibration motor, and portable device of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]

FIG. 1 is a view for explaining an eccentric weight 120 according to the first embodiment. Fig. 1 (a) is a view of the weight support 130 of the eccentric weight 120 as viewed from the front, and Fig. 1 (b) is a view of the weight support 130 of the eccentric weight 120 as viewed from the side. ) Is the eccentric weight 12 Fig. 1 (d) is a view of the weight support 130 at 0 from the bottom.

 FIG. 1 (e) is a perspective view of the weight support 130 in the eccentric weight 120, and FIG. 1 (f) is a perspective view of the eccentric weight 120.

 FIG. 2 is a view for explaining the method of manufacturing the eccentric weight 120 according to the first embodiment. FIG. 2 (a) to FIG. 2 (h) are diagrams showing each step.

 As shown in FIGS. 1 and 2, the eccentric weight 120 according to Embodiment 1 is manufactured by integrating two weights 140 having a circular cross section and a weight support 130. Eccentric weight. Weight 140 is made of a high specific gravity metal. The weight support 130 is made of a metal elastic body having a specific gravity lower than that of the high specific gravity metal constituting the weight 140. The weight support 130 has a weight holding part 134 for holding the weight 140 and a motor shaft holding part 132 for holding the motor shaft 112 (see FIG. 3). The weight holding portion 134 has a weight side protruding portion 135 that reduces the amount of protrusion to the weight 140 side when the weight 140 and the weight support 130 are integrated. As shown in FIG. 2, the weight support 130 is a weight support manufactured by plastically deforming the thin metal member 130a into a predetermined shape and then performing a hardening process.

 Therefore, according to the eccentric weight 120 according to the first embodiment, the eccentric weight is composed of the weight 140 made of a high specific gravity metal and the weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 140. Since the eccentric weight 120 manufactured by integrating 130 is used, the total weight of the eccentric weight 120 can be reduced and the amount of eccentricity in the eccentric weight 120 can be increased. Therefore, by using such an eccentric weight 120, it is possible to configure a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption.

 Further, according to the eccentric weight 120 according to the first embodiment, since the weight support 130 is a weight support that has elastic force, the weight 140 and the weight are used when the vibration motor (and the eccentric weight 120) is used for a long time. It is suppressed that the reliability of joining with the support body 130 falls. For this reason, by using such an eccentric weight 120, it is possible to construct a vibration motor with high long-term reliability.

[0076] Further, according to the eccentric weight 120 according to the first embodiment, when the weight holding part 134 is integrated with the weight 140 and the weight support 130, the amount of protrusion to the weight 140 side is reduced. Since the weight holding portion having the protruding portion 135 is used, the weight 140 has the elastic force of the weight side protruding portion 135. The weight holding portion 134 is held by the added elastic force. For this reason, when the vibration motor (and the eccentric weight 120) is used for a long time, the reliability of the connection between the weight 140 and the weight support 130 is further suppressed. By using it, a vibration motor with higher long-term reliability can be configured.

 Further, according to the eccentric weight 120 according to the first embodiment, since the weight support 130 is a weight support made of an elastic body, the motor shaft 112 (see FIG. 3) has a motor shaft holding portion 1 by elastic force. Will be held at 32. For this reason, when the vibration motor is used for a long time, it is possible to suppress a decrease in the reliability of joining between the motor shaft 112 and the weight support 130, and it is possible to configure a vibration motor with high long-term reliability.

 In the eccentric weight 120 according to the first embodiment, the size of the inner peripheral portion of the weight holding portion 134 before integrating the weight 140 and the weight support 130 is larger than the size of the outer peripheral portion of the weight 140. Try to be small. As a result, the weight 140 is inserted into the weight holding part 134 in a state where the inner peripheral part is expanded, so that the weight 140 is held by the weight holding part 134 by the elastic force of the entire weight holding part 134. Become.

 In the eccentric weight 120 according to the first embodiment, the inner diameter of the motor shaft holding part 132 is preferably smaller than the outer diameter of the motor shaft 112 (see FIG. 3). Thus, when the vibration motor 100 (see FIG. 3 (a)) is assembled using the eccentric weight 120, the motor shaft 112 is inserted into the motor shaft holding part 132 so that the motor shaft 112 is elastically driven. It will be held by the shaft holder 132.

 In the eccentric weight 120 according to the first embodiment, the weight side protruding portion 135 has a structure in which the protruding amount toward the weight 140 side becomes smaller as the weight 140 is inserted into the weight holding portion 134. have.

 For this reason, according to the eccentric weight 120 according to the first embodiment, the weight 140 is inserted into the weight holding portion 134, and the weight 140 gradually pushes the weight side protruding portion 135 outward according to the weight. It will be a crap. For this reason, the operation of inserting the weight 140 into the weight holding portion 134 is facilitated, and the manufacturing cost for manufacturing the eccentric weight 120 can be reduced.

Further, in the eccentric weight 120 according to the first embodiment, the motor shaft holding portion 132 is connected to the motor shaft holding portion 132 as shown in FIGS. 1 (a) and 1 (d). When entering It has a motor shaft side protrusion 133 that reduces the amount of protrusion to the motor shaft 112 side.

 Therefore, according to the eccentric weight 120 according to the first embodiment, the motor shaft 112 is held by the motor shaft holding portion 132 by a stronger elastic force to which the elastic force of the motor shaft side protruding portion 133 is added. become. For this reason, when the vibration motor is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the motor shaft 112 and the weight support 130, and thus a vibration motor with a long-term reliability can be configured. it can.

 In the eccentric weight 120 according to the first embodiment, the motor shaft side protruding portion 133 has a smaller amount of protrusion to the motor shaft 112 side as the motor shaft 112 is inserted into the motor shaft holding portion 132. It has a structure that keeps going.

 Therefore, according to the eccentric weight 120 according to the first embodiment, as the motor shaft 112 is inserted into the motor shaft holding portion 132, the motor shaft 112 gradually moves the motor shaft side protruding portion 133 outward. I will push it. For this reason, the operation of inserting the motor shaft 112 into the motor shaft holding portion 132 is facilitated, and the manufacturing cost when manufacturing the vibration motor using the eccentric weight 120 can be reduced.

 In the eccentric weight 120 according to the first embodiment, the weight support 130 has a shape that surrounds the two weights 140 from the outer periphery in order to hold the two weights 140. This part is called a weight holding part 134. The weight support 130 has a shape surrounding the motor shaft 112 from the outer periphery in order to hold the motor shaft 112. This part is called a motor shaft holding part 132.

 In the eccentric weight 120 according to the first embodiment, the two weights 140 are each held by the weight holding part 134 over a half circumference.

 [0088] For this reason, since the two weights 140 are each held by the weight holding part 134 over a half circumference, the weight 140 and the weight support 130 are joined when the vibration motor 100 is used for a long time. A decrease in reliability is further suppressed.

[0089] In this case, "more than half a circle" means more than half a circle with respect to the entire outer circumference of the weight 140 in a plane perpendicular to the longitudinal direction of the weight 140 (that is, a plane perpendicular to the motor shaft 112). It is. The weight 140 may be held by the weight holding part 134 over the entire length of the weight 140 as in the case of the eccentric weight 120 according to the first embodiment. In the eccentric weight of the invention, the weight holding part 134 does not necessarily have to be held over the entire length of the weight 140.

 [0090] In the eccentric weight 120 according to the first embodiment, as described above, the weight support 130 is subjected to a hardening process after plastically deforming the thin metal member 130a into a predetermined shape as shown in FIG. It consists of the elastic body manufactured by.

 Therefore, according to the eccentric weight 120 according to the first embodiment, the amount of the material constituting the weight support 130 can be made extremely small while maintaining the necessary strength. Thereby, the total weight of the eccentric weight 120 can be reduced, and the amount of eccentricity in the eccentric weight 120 can be further increased. For this reason, by using such an eccentric weight 120, it is possible to construct a vibration motor that can obtain a necessary vibration amount with lighter weight and less power consumption.

 In the eccentric weight 120 according to the first embodiment, the Vickers hardness (HV) of the weight support 130 is 150 or more.

 By configuring in this way, the weight support 130 can hold the weight 140 with a strong elastic force and can hold the motor shaft 112 with a strong elastic force. From this point of view, the Vickers hardness (Hv) of the weight support 130 is preferably 200 or more, more preferably 250 or more.

 In the eccentric weight 120 according to the first embodiment, the thickness of the thin metal member 130a is set to 0.1 mm. Therefore, while maintaining the strength required for the weight support 130, the total weight of the weight support 130 can be reduced and the amount of eccentricity in the eccentric weight 120 can be further increased.

 In the eccentric weight 120 according to the first embodiment, as shown in FIG. 1 (d), the length along the motor shaft 112 in the weight 140 (along the longitudinal direction of the weight 140) is 4 mm. is there. Further, the length along the motor shaft 112 in the weight holding portion 134 of the weight support 130 is also 4 mm, and the length along the motor shaft 112 in the motor shaft holding portion 132 of the weight support 130 is also 4 mm. .

Therefore, in the eccentric weight 120 according to the first embodiment, the weight 140 holds the weight in the weight support 130 in all the lengths (4 mm) along the long direction of the weight 140. Held in part 134. As a result, the weight 140 is held on the weight support 130 by tension.

 In the eccentric weight 120 according to the first embodiment, as shown in FIG. 1, the weight 140 has a circular cross-sectional shape, so that the weight 140 is connected to any end (the end S shown in FIG. 1 (b)). , S.)

 Since the weight holding part 134 can be inserted from the 1 2 side, the degree of freedom in placing the weight 140 in the weight holding part 134 is increased, and workability is improved. For this reason, the manufacturing cost at the time of manufacturing the eccentric weight 120 can be made low.

In the eccentric weight 120 according to the first embodiment, the weight 140 is made of a tungsten sintered alloy, and the weight support 130 is made of martensitic stainless steel having a specific gravity lower than that of the tungsten alloy.

 [0099] For this reason, since the weight support 130 is made of a martensitic stainless steel after an elastic hardening treatment, the durability of the weight support 130 is improved, and the weight support 130 and the weight 140 are combined. It becomes possible to integrate more firmly, and it is further suppressed that the reliability of the connection between the weight 140 and the weight support 130 is lowered when the vibration motor (and the eccentric weight 120) is used for a long time. . Therefore, by using such an eccentric weight 120, it is possible to configure a vibration motor with high long-term reliability.

 [0100] In addition, martensitic stainless steel is a material that has relatively high corrosion resistance and is difficult to crack. Therefore, even if it is used as a weight support, it is not necessary to apply a plating. As a result, the joint between the weight support 130 and the plating film and the plating film itself are not cracked, and no cracks are generated due to cracks. It is suppressed that the reliability regarding the holding | maintenance of the motor shaft 112 falls.

 [0101] In addition, martensitic stainless steels are more viscous than tungsten alloys, so brittle and fragile weights such as tungsten alloys should be held around the entire circumference with viscous martensitic stainless steels. Therefore, the problem that the weight is easily broken is also suppressed.

[0102] In addition, since martensitic stainless steel is less expensive than tungsten alloys and the like, the weight support 130 is made of such relatively inexpensive martensitic stainless steel, so that the eccentric weight 120 of It becomes easy to reduce the manufacturing cost. [0103] In the eccentric weight 120 according to Embodiment 1, the weight 140 is made of a tungsten alloy. Since the tungsten alloy has a very high specific gravity, the amount of eccentricity in the eccentric weight 120 can be further increased. For this reason, by using such an eccentric weight 120, it is possible to configure a vibration motor that can obtain a necessary vibration amount with further reduced power consumption.

 [0104] In the eccentric weight 120 according to the first embodiment, the weight 140 itself does not need a function for holding the motor shaft 112. Therefore, the shape of the weight is extremely simple (cylindrical shape). Is adopted.

 [0105] As a manufacturing method of the weight 140, a manufacturing method in which a tungsten alloy is sintered into a weight shape to obtain the weight 140 can be adopted. However, in the eccentric weight 120 according to the first embodiment, the tungsten alloy is made of A round bar with a simple shape is made by sintering, and the round bar is cut into short pieces to produce a weight of 140. By doing so, the amount of the additive (for example, copper) contained in the tandasten alloy can be reduced, so that the specific gravity can be increased and the amount of eccentricity in the eccentric weight 120 can be further increased. become able to.

 [0106] The eccentric weight 120 according to Embodiment 1 can be manufactured, for example, by the following method.

 (1) A sheet metal member 130a made of martensitic stainless steel is prepared (FIG. 2 (a)). In this thin metal member 130a, a portion 135a that becomes the weight side protruding portion 135 and a portion 133a that becomes the motor shaft side protruding portion 133 are already formed. In FIG. 2 (a), the lines indicated by reference signs X to X are virtual lines that serve as a reference during processing.

 1 6

 (2) Next, the part from one end E of the thin metal member 130a to the symbol X is rounded by plastic working to form a part corresponding to the motor shaft holding part 132 (FIG. 2 (b)) .

 (3) Next, the portion from the symbol X to the symbol X in the thin metal member 130a, from the symbol X

 2 3 3

The part extending to X and the part extending from X to X are deformed by plastic deformation and separated.

4 4 5

 A portion corresponding to the copper holding portion 134 is formed (FIG. 2 (c) to FIG. 2 (e)).

 (4) Next, the part from the symbol X to the other end E in the thin metal member 130a is plasticized.

 6 2

A part corresponding to the motor shaft holding part 132 is formed by machining to form a member 130b having substantially the same shape as the weight support body 130 (FIG. 2 (f)). (5) Next, the member 130b having substantially the same shape as the weight support 130 is subjected to a hardening process by quenching to produce the weight support 130 (FIG. 2 (g)).

 (6) A tungsten alloy round bar having the same cross-sectional shape as that of the weight 140 is prepared.

 (7) Next, the above-mentioned round bar is cut into a predetermined length to manufacture the weight 140.

 [0109] (8) The weight 140 is inserted into the weight holding portion 134 in a state where the inner peripheral portion is expanded. At this time, the weight 140 gradually pushes the weight side protruding portion 135 outward as the weight 140 is inserted into the weight holding portion 134. Thereafter, after the weight 140 is completely inserted into the weight holding portion 134, the state in which the inner peripheral portion is pushed out is released. As a result, the weight 140 is held in the weight holding portion 134 by the elastic force of the weight side protruding portion 135 and the elastic force of the entire weight support 134.

 (9) Thereby, the eccentric weight 120 in which the weight 140 is strongly held by the weight holding portion 134 by the elastic force is manufactured (FIG. 2 (h)).

 FIG. 3 is a view for explaining the vibration motor 100 according to the first embodiment. 3 (a) is a perspective view of the vibration motor 100 according to the first embodiment, FIG. 3 (b) is a view of the vibration motor 100 according to the first embodiment as viewed from the front, and FIG. FIG. 3 is a view of a part of the vibration motor 100 according to the first embodiment as viewed from the side.

 As shown in FIG. 3, the vibration motor 100 according to the first embodiment is a vibration motor including a motor body 110 and an eccentric weight 120. The vibration motor 100 according to the first embodiment is an eccentric weight that can be suitably used for a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption, as described above. It is equipped with an excellent eccentric weight 120 that suppresses a decrease in the reliability of the connection between the weight and the weight support when used for a long time. For this reason, the vibration motor 100 according to the first embodiment is a vibration motor having such an excellent eccentric weight 120, so that a necessary vibration amount can be obtained with light weight and low power consumption, and high reliability for a long time. It becomes a vibration motor.

[0112] For this reason, it is possible to obtain a necessary amount of vibration with such light weight and low power consumption, and to use the excellent vibration motor 100 with high reliability for a long time as a vibration motor for portable devices. The device can be a portable device with light weight, low power consumption and high reliability for a long time. [Embodiments 2 to 3]

 FIG. 4 is a view for explaining the eccentric weight 220 according to the second embodiment. Fig. 4 (a) is a view of the weight support 230 of the eccentric weight 220 as viewed from the front, and Fig. 4 (b) is a view of the weight 240 of the eccentric weight 220 as viewed from the front. It is the figure which looked at the eccentric weight 220 from the front.

 [0114] The eccentric weight 220 according to the second embodiment is different from the eccentric weight 120 according to the first embodiment in the number and cross-sectional shape of the weight (and accordingly, the cross-sectional shape of the weight support). That is, as shown in FIG. 4, the eccentric weight 220 according to the second embodiment includes a single weight 240 having a substantially fan-shaped cross-sectional shape (and a single weight 240 having a substantially fan-shaped cross-sectional shape accordingly). It has a weight support 230) having a cross-sectional shape to hold. The weight holding part 234 in the weight support body 230 has two weight side protrusions 235 and 235.

 FIG. 5 is a view for explaining the eccentric weight 320 according to the third embodiment. Fig. 5 (a) shows the weight support 330 of the eccentric weight 320 as seen from the front, and Fig. 5 (b) shows the weight 340 of the eccentric weight 320 as seen from the front. It is the figure which looked at the eccentric weight 320 from the front.

 [0116] As with the eccentric weight 220 according to the second embodiment, the eccentric weight 320 according to the third embodiment also has the same number of weights and cross-sectional shape (and the corresponding cross-sectional shape of the weight support body) as the first embodiment. This is different from the case of the eccentric weight 120. That is, as shown in FIG. 5, the eccentric weight 320 according to the third embodiment includes one weight 340 having a substantially fan-shaped cross-sectional shape (and one weight having a substantially fan-shaped cross-sectional shape accordingly). A weight support 330) having a cross-sectional shape to hold 340; However, unlike the case of the eccentric weight 220 according to the second embodiment, the weight holding portion 334 in the weight support 330 has four weight-side protruding portions 335, 335, 335, and 335.

[0117] As described above, the eccentric weights 220 and 320 according to the second or third embodiment have the same number of weights and the cross-sectional shape (and the corresponding cross-sectional shape of the weight support body) as the eccentric weight 120 according to the first embodiment. Unlike other cases, an eccentric weight is manufactured by integrating a weight made of a high specific gravity metal and a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight. Since the eccentric weights 220 and 320 are used, the total weight of the eccentric weights 220 and 320 can be reduced and the amount of eccentricity in the eccentric weights 220 and 320 can be increased, as in the case of the eccentric weight 120 according to the first embodiment. . Therefore, by using such eccentric weights 220 and 320, it is possible to configure a vibration motor that can obtain a large amount of vibration with light weight and low power consumption.

 [0118] Further, according to the eccentric weights 220 and 320 according to the second or third embodiment, the weight support body is made of the elastic body force, and thus the split weight support bodies 230 and 330, so that the split weights 240 and 340 are held equally. The weight holding portions 234 and 334 are held by the entire elastic force. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, the reliability of the connection between the weight 240, 340 and the weight support 230, 330 is suppressed, and such an eccentric weight 220, 320 is suppressed. By using, a vibration motor with high long-term reliability can be configured.

 [0119] Further, according to the eccentric weights 220 and 320 according to the second or third embodiment, when the weight holding part is integrated with the weight and the weight support, the weight-side protrusion is reduced to the weight side. Since the weight holding parts 234 and 334 having the parts 2 35 and 335 are used, the weights 240 and 340 are held by the weight holding parts 234 and 334 with a stronger elastic force to which the elastic force of the weight side protruding parts 235 and 335 is added. It will be. Therefore, when the vibration motor (and eccentric weight 220, 320) is used for a long time, the reliability of the connection between the weight 240, 340 and the weight support 230, 330 is reduced. By using such eccentric weights 220 and 320, a vibration motor with higher long-term reliability can be configured.

 [Embodiments 4 to 5]

 FIG. 6 is a view for explaining the eccentric weight 420 according to the fourth embodiment. Fig. 6 (a) is a front view of the weight support 430 of the eccentric weight 420, Fig. 6 (b) is a cross-sectional view of Fig. 6 (a), and Fig. 6 (c) is a diagram. Fig. 6 (b) is a cross-sectional view taken along the line A-A, and Fig. 6 (d) shows Fig. 6 (

2 2 3 3

 FIG. 6 (b) is a cross-sectional view taken along the line AA, and FIG. 6 (e) is a view of the eccentric weight 420 as viewed from the front.

 4 4

[0121] The eccentric weight 420 according to the fourth embodiment has a structure very similar to the eccentric weight 120 according to the first embodiment, but the structure of the weight side protrusion is the eccentric weight 120 according to the first embodiment. Is different. That is, the weight side protrusion 435 in the eccentric weight 420 according to the fourth embodiment is formed of a rib having a rectangular planar shape as shown in FIG. 6 (b). And weight side protrusion In the portion 435, two opposite sides of the four sides of the rectangle are connected to the main body of the weight holding portion 434, and the other two sides are separated from the weight holding portion 434.

FIG. 7 is a view for explaining the eccentric weight 520 according to the fifth embodiment. Fig. 7 (a) is a front view of the weight support 530 of the eccentric weight 520, Fig. 7 (b) is a cross-sectional view taken along the line 8-A in Fig. 7 (a), and Fig. 7 (c) is the eccentricity. Fig. 7 (d) is a front view of the weight 520.

5 5

 FIG. 4 is a perspective view of an eccentric weight 520. FIG.

 [0123] Similarly to the eccentric weight 420 according to the fourth embodiment, the eccentric weight 520 according to the fifth embodiment also has a structure similar to that of the eccentric weight 120 according to the first embodiment. The structure of the part is different from that of the eccentric weight 120 according to the first embodiment. That is, the weight side protrusion 535 of the eccentric weight 520 according to Embodiment 5 is a rib whose rectangular shape is a plane as shown in FIG. 7 (b). In the weight-side protruding portion 535, two opposite sides of the four sides of the rectangle are connected to the body of the weight holding portion 534, and the other two sides are separated from the weight holding portion 534. Les.

 [0124] As described above, the eccentric weights 420 and 520 according to the fourth or fifth embodiment are different from the case of the eccentric weight 120 according to the first embodiment in that the structure of the weight side protrusion is as shown in FIGS. Although different, eccentric weights 420, 520 manufactured by integrating a weight made of a high specific gravity metal with a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight. Therefore, as in the case of the eccentric weight 120 according to the first embodiment, the total weight of the eccentric weights 420 and 520 can be reduced and the amount of eccentricity in the eccentric weights 420 and 520 can be increased. For this reason, by using such eccentric weights 420 and 520, it is possible to configure a vibration motor that is lightweight and can obtain a large amount of vibration with low power consumption.

 [0125] Further, according to the eccentric weights 420 and 520 according to the embodiment 4 or 5, the weight support body is made of the elastic body force, and the split weight support bodies 430 and 530, so the split weights 440 and 540 are held in the same volume. 534 is held by the weight holding parts 434 and 534 by the elastic force of the whole. For this reason, when the vibration motor (and the eccentric weight) is used for a long time, the reliability of the connection between the weights 440 and 540 and the weight support 430 and 530 is suppressed, and such an eccentric weight 420, 520 is suppressed. By using, a vibration motor with high long-term reliability can be configured.

[0126] Further, according to the eccentric weights 420 and 520 according to the fourth or fifth embodiment, the weight holding portion is a weight. When the weight and the weight support are integrated, the weight-side protrusion 4 35, 535 is used as the weight holding part 434, 534, so that the weight 440, 540 is the weight-side protrusion 435. , 535 is added to the weight holding part 434, 534 with a stronger elastic force. For this reason, when the vibration motor (and eccentric weight) is used for a long time, the reliability of the connection between the weights 440 and 540 and the weight support bodies 430 and 530 is further suppressed. By using the weights 420 and 520, a vibration motor with higher long-term reliability can be configured.

 [0127] In the eccentric weight 520 according to the fifth embodiment, the weight support body 530 includes weights 540 from both sides in the direction along the motor shaft, as shown in Figs. 7 (b) and 7 (d). It has a weight holding frame 536 that holds the weight.

 For this reason, according to the eccentric weight 520 according to the fifth embodiment, the weight support 530 can hold the weight 540 from both sides in the direction along the motor shaft. In addition, when the eccentric weight 520) is used for a long time, the reliability of the connection between the weight 540 and the weight support body 530 is further suppressed, so by using such an eccentric weight 520, A vibration motor with higher long-term reliability can be configured.

 [Embodiment 6]

 FIG. 8 is a perspective view of an eccentric weight 620 according to the sixth embodiment.

 [0130] The eccentric weight 620 according to the sixth embodiment has a structure very similar to the eccentric weight 120 according to the first embodiment, but is implemented in that a weight support body provided with a predetermined opening is used. This is different from the case of the eccentric weight 120 according to Form 1. In the eccentric weight 620 according to the sixth embodiment, as shown in FIG. 8, the weight support 630 is manufactured by using a thin metal member provided with a predetermined opening.

[0131] For this reason, according to the eccentric weight 620 according to the sixth embodiment, the amount of the material constituting the weight support 630 can be further reduced while maintaining the required strength. As a result, the total weight of the eccentric weight 620 can be further reduced, and the amount of eccentricity in the eccentric weight 620 can be further increased. For this reason, by using such an eccentric weight 620, it is possible to construct a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption. [Embodiment 7]

 FIG. 9 is a view for explaining the eccentric weight 720 according to the seventh embodiment. FIG. 9A is a view of the eccentric weight 720 as viewed from the front, and FIG. 9B is a view of the eccentric weight 720 coupled to the motor shaft 712 as viewed from the front.

 [0133] Unlike the eccentric weight 120 according to the first embodiment, the eccentric weight 720 according to the seventh embodiment does not have a weight side protrusion for holding the weight with a strong elastic force. Instead, the weight support 730 in the seventh embodiment has a structure in which the weight holding part 732 holds the weight 740 with a stronger elastic force when the motor shaft 712 is inserted into the motor shaft holding part 732. Have.

 In other words, in the eccentric weight 720 according to the seventh embodiment, a slight gap is formed between the weight holding portion 734 and the weight 740 before the motor shaft 712 is inserted (FIG. 9). (See part C of (a).) After the motor shaft 712 is inserted, the motor shaft 712 pushes and spreads the motor shaft holding portion 732, so that the motor shaft holding portion 732 and the weight holding portion 734 are elastic. As a result, the gap formed between the weight holding portion 734 and the weight 740 disappears (see FIG. 9B). For this reason, the weight holding portion 732 holds the weight 740 with a stronger elastic force.

 Therefore, according to the eccentric weight 720 according to the seventh embodiment, it is further suppressed that the reliability of the connection between the weight 740 and the weight support 730 is lowered when the vibration motor is used for a long time. By using such an eccentric weight 720, a vibration motor with higher long-term reliability can be configured.

 [Embodiment 8]

 FIG. 10 is a view for explaining the eccentric weight 820 according to the eighth embodiment. FIG. 10 (a) is a view of the weight support 830 of the eccentric weight 820 as seen from the front, and FIG. 10 (b) is a view of the eccentric weight 820 as seen from the front. FIG. 10 (c) is a front view of the eccentric weight 820 coupled to the motor shaft 812. FIG.

[0137] As with the eccentric weight 720 according to the seventh embodiment, the eccentric weight 820 according to the eighth embodiment does not have a weight side protrusion for holding the weight with a stronger elastic force. However, the weight support 830 in the eighth embodiment is the case of the eccentric weight 720 according to the seventh embodiment. In contrast, when the weight 840 is inserted into the weight holding portion 834, the space defined by the motor shaft holding portion 832 is reduced.

In the eccentric weight 820 according to the eighth embodiment, the area of the space defined by the motor shaft holding portion 832 is approximately the same as the cross-sectional area of the motor shaft 812 before the weight 840 is inserted. (Refer to Fig. 10 (a).) After the weight 840 is inserted, the weight 840 pushes and spreads the weight holding portion 834, so that the motor shaft holding portion 832 is elastically deformed and the motor shaft holding portion 832 The defining space becomes smaller (see Fig. 10 (b)). Therefore, when the motor shaft 812 is inserted into the motor shaft holding portion 832, the motor shaft holding portion 832 holds the motor shaft 812 with a stronger elastic force (see FIG. 10C). Further, in this case, when the motor shaft 812 is inserted into the motor shaft holding portion 832, the weight holding portion 834 is elastically deformed and tends to be further reduced, so that the weight holding portion 834 has a stronger elastic force. It comes to hold.

 [0139] Therefore, according to the eccentric weight 820 according to the eighth embodiment, when the vibration motor is used for a long time, the reliability of the connection between the weight 840 and the weight support 830 decreases, or the motor shaft 812 Since it is further suppressed that the reliability of joining with the weight support 830 is lowered, a vibration motor with higher long-term reliability can be configured.

 [Embodiment 9]

 FIG. 11 is a view for explaining the eccentric weight 920 according to the ninth embodiment. Fig. 11 (a) is a view of the weight support 930 of the eccentric weight 920 from the front, and Fig. 11 (b) is a view of the weight support 930 of the eccentric weight 920 from the side. c) is a view of the weight support 930 of the eccentric weight 920 as seen from the bottom, and Fig. 11 (d) shows the A-in Fig. 11 (a)

6

FIG. 11 (e) is a perspective view of the weight support 930 in the eccentric weight 920.

6

 FIG. 11 (f) is a perspective view of the eccentric weight 920.

FIG. 12 is a view for explaining the method of manufacturing the eccentric weight 920 according to the ninth embodiment. FIG. 12 (a) to FIG. 12 (i) are diagrams showing each process.

FIG. 13 is a view for explaining the vibration motor 900 according to the ninth embodiment. FIG. 13 (a) is a perspective view of the vibration motor 900 according to the ninth embodiment, FIG. 13 (b) is a view of the vibration motor 900 according to the ninth embodiment as viewed from the front, and FIG. Vibration motor according to embodiment 9 It is the figure which looked at a part of 900 from the side.

 [0142] The eccentric weight 920 according to the ninth embodiment is similar to the eccentric weight 720 according to the seventh embodiment when the motor shaft 912 (see Fig. 13) is inserted into the motor shaft holding portion 932. 934 Force S Has a structure that holds the weight 940 with a stronger elastic force.

 That is, in the eccentric weight 920 according to the ninth embodiment, when the motor shaft 912 is inserted, the motor shaft 912 pushes the motor shaft holding portion 932 and the weight holding portion 934 becomes stronger. The weight 940 is held by the elastic force.

 Therefore, according to the eccentric weight 920 according to the ninth embodiment, as in the case of the eccentric weight 720 according to the seventh embodiment, the weight 940 and the weight support 930 when the vibration motor 900 is used for a long time. Therefore, the use of such an eccentric weight makes it possible to construct a vibration motor with higher long-term reliability.

 In the eccentric weight 920 according to the ninth embodiment, as shown in FIGS. 11 to 13, the weight support body 930 includes a weight holding frame 936 that holds the weight 940 from one side in the direction along the motor shaft 912. have.

 Therefore, according to the eccentric weight 920 according to the ninth embodiment, the weight support body 930 can hold the weight 940 from one side in the direction along the motor shaft 912, as shown in FIG. Therefore, when the vibration motor (and the eccentric weight 920) is used for a long time, the reliability of the connection between the weight 940 and the weight support 930 is further suppressed, so that such an eccentric weight 920 By using, it is possible to construct a vibration motor with higher long-term reliability.

 Note that, as shown in FIG. 12, the eccentric weight 920 according to the ninth embodiment plastically deforms one thin metal member 930a into a predetermined shape as in the case of the eccentric weight 120 according to the first embodiment. Then, it can be produced by performing a curing treatment.

 [Embodiment 10]

FIG. 14 is a view for explaining the eccentric weight 1020 according to the tenth embodiment. Fig. 14 (a) is a view of the weight support 1030 of the eccentric weight 1020 as viewed from the front, and Fig. 14 (b) is a view of the weight support 1030 of the eccentric weight 1020 as viewed from the side. c) is a perspective view of the eccentric weight 1020, and FIG. It is the figure which looked at a part from the side.

 The eccentric weight 1020 according to the tenth embodiment has a structure very similar to the eccentric weight 120 according to the first embodiment, but the length of the weight holding portion 1030 along the longitudinal direction of the weight 1040 is actual. This is different from the case of the eccentric weight 120 according to the first embodiment. That is, in the eccentric weight 1020 according to the tenth embodiment, as shown in FIGS. 14 (c) and 14 (d), the length of the weight holding portion 1030 along the longitudinal direction of the weight 1040 is related to the first embodiment. The length is about 50% of the case of the eccentric weight 120.

 Thus, in the eccentric weight 1020 according to the tenth embodiment, the length of the weight holding part along the longitudinal direction of the weight is different from that of the eccentric weight 120 according to the first embodiment, but other than this In this respect, since the configuration is the same as that of the eccentric weight 120 according to the first embodiment, the effect of the eccentric weight 120 according to the first embodiment is obtained as it is.

 [0151] Further, according to the eccentric weight 1020 according to the tenth embodiment, the length of the weight holding portion 1030 along the longitudinal direction of the weight 1040 is about 50% as compared with the case of the eccentric weight 120 according to the first embodiment. Therefore, the total weight of the eccentric weight 1020 can be further reduced, and the eccentric amount of the eccentric weight 1020 can be further increased. Therefore, according to the eccentric weight 1020 according to the tenth embodiment, it is possible to configure a vibration motor that can obtain a necessary vibration amount with light weight and low power consumption.

 As shown in FIG. 14 (d), the vibration motor 1000 according to the tenth embodiment includes a weight holding portion 1034 in which the length of the weight holding portion 1034 along the longitudinal direction of the weight 1040 is shorter than the weight 1040. An eccentric weight 1020 that holds the weight 1040 at an eccentric position along the longitudinal direction of the weight 1040 is provided. The eccentric weight 1020 is fixed to the motor main body 1010 in a direction in which the distance between the motor shaft holding portion 1032 and the motor main body 1010 approaches.

 Therefore, according to the vibration motor 1000 according to the tenth embodiment, the distance between the motor shaft holding portion 1032 of the eccentric weight 1020 and the bearing 1014 of the motor main body 1010 is close, so that the motor shaft 1012 rotates. Deflection of the motor shaft 1012 is suppressed. As a result, the eccentric weight 1 020 rotates more stably, and the eccentric vibration characteristics of the vibration motor 1000 are improved.

[0154] The eccentric weight, vibration motor, and portable device of the present invention have been described based on the above embodiments, but the present invention is not limited to the above embodiments. The present invention can be implemented in various forms without departing from the scope of the invention, and for example, the following modifications are possible.

 (1) In the eccentric weights 120 to 1020 of the above embodiments, the force using tungsten alloy as the weight is not limited to this. For example, tungsten, osmium, osmium alloy, gold, gold alloy, iridium, iridium alloy, and other metals having higher specific gravity than the weight support can be used.

 (2) In the eccentric weights 120 to 1020 of the above embodiments, the force using martensitic stainless steel as the thin metal member is not limited to this. For example, a metal having quenching hardenability other than martensitic stainless steel can be used. Moreover, the metal which has age-hardening property can also be used. In this case, precipitation hardening stainless steel, beryllium copper alloy, nickel manganese copper alloy or precipitation hardening titanium alloy can be used as the metal having age hardening.

 [0157] (4) In the eccentric weights 120 to 1020 of the above-described embodiments, as a weight, a cut body or a round bar obtained by machining a sintered body made of a round bar into a cross-sectional shape that is the same as the cross-sectional shape of the weight. However, the present invention is not limited to this. For example, as a weight, a sintered body sintered in the shape of a weight or a sintered body with a deformed bar force having the same cross-sectional shape as the weight cross-sectional shape (for example, a circle, an ellipse, a fan shape, etc.) is shortened. Use a cut one.

 [0158] (5) The eccentric weights 720 to 920 of the respective embodiments 7 to 9 do not have the motor shaft side protruding portion and the weight side protruding portion. The motor shaft side protruding portion 133 and the weight side protruding portion 135 as in the eccentric weight 120 of the first embodiment may be provided.

 [0159] (6) The vibration motor of the present invention is preferably used for portable devices such as mobile phones and PDAs, and is also preferably used for game machine remote controls, pachinko operating units, electric toothbrushes, and the like. Can do.

Claims

The scope of the claims  [1] A weight made of a high specific gravity metal,  A weight support made of a metal elastic body having a weight holding portion for holding the weight and a motor shaft holding portion for holding the motor shaft and having a specific gravity lower than that of the high specific gravity metal constituting the weight. Is an eccentric weight manufactured by integrating  The eccentric weight is characterized in that the weight holding portion has a weight side protruding portion that reduces a protruding amount to the weight side when the weight and the weight support are integrated.  [2] In the eccentric weight according to claim 1,  The weight-side protruding portion has a structure in which the amount of protrusion to the weight side decreases as the weight is inserted into the weight holding portion. [3] In the eccentric weight according to claim 1 or 2,  The eccentric weight, wherein the motor shaft holding portion has a motor shaft side protruding portion that reduces the amount of protrusion to the motor shaft side when the motor shaft is inserted into the motor shaft holding portion.  [4] The eccentric weight according to claim 3,  The eccentricity of the motor shaft-side protruding portion has a structure in which the amount of protrusion toward the motor shaft side decreases as the motor shaft is inserted into the motor shaft holding portion. weight. [5] A weight made of a high specific gravity metal,  A weight support made of a metal elastic body having a weight holding portion for holding the weight and a motor shaft holding portion for holding the motor shaft and having a specific gravity lower than that of the high specific gravity metal constituting the weight. Is an eccentric weight manufactured by integrating  The eccentric weight is characterized in that the weight support has a structure in which the weight holding part holds the weight with a stronger elastic force when the motor shaft is inserted into the motor shaft holding part. [6] A weight made of a high specific gravity metal, Weight holding part for holding the weight and motor shaft for holding the motor shaft An eccentric weight manufactured by integrating a weight support made of an elastic body of a metal having a holding portion and having a specific gravity lower than that of the high specific gravity metal constituting the weight,  The weight support body has a structure in which the space defined by the motor shaft holding portion is reduced when the weight body and the weight support body are integrated. [7] In the eccentric weight according to any one of claims 1 to 6,  The eccentric weight is characterized in that the weight support is made of an elastic body manufactured by plastically deforming a thin metal member into a predetermined shape and then performing a hardening process. [8] In the eccentric weight according to claim 7,  An eccentric weight, wherein the weight support has a Vickers hardness (Hv) of 150 or more.  [9] In the eccentric weight according to claim 7 or 8,  An eccentric weight, wherein the thin metal member is made of a metal having quench hardening properties.  [10] In the eccentric weight according to claim 9,  An eccentric weight characterized in that the quench-hardening metal is martensitic stainless steel. [11] In the eccentric weight according to claim 7 or 8,  The thin metal member is made of an age-hardening metal, and is an eccentric weight.  [12] The eccentric weight according to claim 11, wherein  The eccentric weight, wherein the age-hardening metal is precipitation hardened stainless steel, beryllium copper alloy, nickel manganese copper alloy or precipitation hardened titanium alloy. [13] The eccentric weight according to any one of claims 7 to 12:  An eccentric weight, wherein the thickness of the thin metal member is in the range of 0.05 mm to 0.5 mm.  [14] In claim 7 to 13, the eccentric weight according to any one of An eccentric weight, wherein the thin metal member is provided with a predetermined opening. The eccentric weight according to any one of claims 1 to 14:  The eccentric weight is made of tungsten, tungsten alloy, osmium, osmium alloy, gold, gold alloy, iridium or iridium alloy.  The eccentric weight according to any one of claims 1 to 15:  The eccentric weight is characterized in that the weight is held in the weight holding portion over a half circumference.  The eccentric weight according to any one of claims 1 to 16:  The eccentric weight is characterized in that the weight support body has a weight holding frame for holding the weight from one side or both sides in a direction along the motor shaft.  The eccentric weight according to any one of claims 1 to 17:  The eccentric weight is characterized in that the weight has a plane-symmetric shape with a predetermined first plane including the central axis of the motor shaft holding portion as a symmetry plane.  A vibration motor comprising a motor body and the eccentric weight according to any one of claims 1 to 18.  The vibration motor according to claim 19,  As the eccentric weight, the weight holding part whose length along the longitudinal direction of the weight is shorter than the weight holds the weight at an eccentric position along the longitudinal direction of the weight. Equipped with an eccentric weight  The eccentric weight is fixed to the motor main body in a direction in which the distance between the motor shaft holding portion and the motor body approaches.  21. A portable device comprising the vibration motor according to claim 19.