WO2006040808A1 - Eccentric weight, method for producing the same, vibration motor and portable apparatus - Google Patents

Abstract

An eccentric weight (1720) comprising a weight (1740) composed of a high specific gravity metal, and a weight support (1730) composed of a metal having a specific gravity lower than that of the high specific gravity metal composing the weight (1740) and having a weight holding section (1734) for holding the weight (1740) over the entire circumference thereof, a motor shaft holding section (1732), and a section (1736) for coupling the weight holding section (1734) and the motor shaft holding section (1732), wherein the coupling section (1736) has an area (1738) having a wall thickness smaller than the length along a motor shaft (1712) at the motor shaft holding section (1732). Total weight of the eccentric weight (1720) can be lightened while increasing eccentricity thereof. When the eccentric weight (1720) is used for a long time, bonding reliability of the weight (1740) and the weight support (1730) can be prevented from lowering.

Description

 Eccentric weight, manufacturing method thereof, vibration motor and portable device

 TECHNICAL FIELD [0001] The present invention relates to an eccentric weight, a manufacturing method thereof, a vibration motor, and a portable device.

 In mobile phones and PDAs, vibration motors are used to notify incoming calls by vibration. FIG. 21 is a diagram for explaining a conventional vibration motor and an eccentric weight. Fig. 21 (a) is a perspective view of a vibration motor, Fig. 21 (b) is a cross-sectional view of an eccentric weight cut along a plane perpendicular to the motor axis, and Fig. 21 (c) is an eccentric weight along the motor axis. FIG. In FIGS. 21 (b) and 21 (c), the position of the eccentric weight in FIG. 21 (a) in the rotational direction is changed and shown.

 [0003] As shown in FIG. 21, a conventional vibration motor 1800 includes a small cylindrical motor body 1810 and an eccentric weight 1820 having a substantially fan shape and having a force such as a sintered body of tungsten. The motor shaft 1812 of the motor body 1810 is generally held in the motor shaft holding hole 1822 of the eccentric weight 1820. Eccentric weight 1820 is attached to the tip of motor shaft 1812 by crimping by deforming motor shaft holding hole 1822 by applying an external force to the motor shaft holding hole 1822 through which the motor shaft 1812 is inserted. (For example, see Patent Document 1).

 [0004] By the way, for a mobile phone, a PDA, and the like, there is a demand for a vibration motor that can obtain a necessary amount of vibration with low power consumption and light weight. For this reason, other eccentric weights as shown in FIG. 22 have been proposed as eccentric weights used in such vibration motors. FIG. 22 is a view for explaining another conventional eccentric weight. Fig. 22 (a) is a front view, Fig. 22 (b) is a cross-sectional view along the line A-A in Fig. 22 (a), Fig. 22 (c) is a front view of the component, and Fig. 22 (d) ) Is a sectional view taken along the line BB in FIG. 22 (c). In FIGS. 22 (a) and 22 (b), a part of the motor body 1910 is also shown.

Another conventional eccentric weight 1920 has a motor shaft 1 of a motor body 1910 as shown in FIG. A cylindrical weight support 1930 having a motor shaft holding hole 1932 for holding 912 and having a low specific gravity metal force, and a substantially half-pipe weight 1940 having a high specific gravity metal force (for example, a patent) (Refer to Reference 1.) o For this reason, the weight 1940 also has a high specific gravity metal force, so the center of gravity of the eccentric weight 1920 is arranged at a position where the center axial force of the motor shaft holding hole 1932 is also separated. As a result, the eccentric amount of the eccentric weight 1920 increases, and by using such other conventional eccentric weight 1920, a vibration motor that can obtain a required vibration amount with light weight and low power consumption can be configured.

[0006] Patent Document 1: JP 2001-129479 A

 Disclosure of the invention

 Problems to be solved by the invention

 However, in the other conventional eccentric weight 1920 described above, the weight 1940 is integrally bonded and fixed to a part of the outer surface 1934 of the weight support 1930 via the brazing portion 1950. 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.

 [0008] Therefore, the present invention has been made to solve such a problem, and 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. Thus, an object of the present invention is to provide an eccentric weight and a method of manufacturing the same, in which the reliability of the connection between the weight and the weight support is suppressed even when such a vibration motor is used for a long time. It is another object of the present invention to provide a vibration motor and a portable device having such an excellent eccentric weight.

 Means for solving the problem

(1) The eccentric weight of the present invention includes a weight having a high specific gravity metal force, a weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding a motor shaft, and the weight An eccentric weight having a holding portion and a connecting portion for connecting the motor shaft holding portion, and comprising a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight, the connecting portion Is characterized in that it has a thin region having a thickness of a value smaller than the length along the motor shaft in the motor shaft holding portion, and z or holes opened on both sides along the motor shaft. (2) The eccentric weight of the present invention includes a weight having a high specific gravity metal force, a weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding a motor shaft, and the weight An eccentric weight having a holding portion and a connecting portion for connecting the motor shaft holding portion, and comprising a weight support made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight, the connecting portion Has a shape that forms a single connecting rod when viewed from the direction along the motor shaft.

 For this reason, according to the eccentric weight described in (1) or (2) above, the eccentric weight has a specific gravity lower than that of the high specific gravity metal and the high specific gravity metal constituting the weight. Since the eccentric weight is provided with a weight support made of metal, 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.

 [0012] Further, according to the eccentric weight described in the above (1) or (2), since the weight is held by the weight holding portion in the weight support over a half circumference, the vibration motor (and the eccentric weight) When copper is used for a long time, it is possible to suppress a decrease in the reliability of bonding between the weight and the weight support. Therefore, by using such an eccentric weight, a vibration motor with high long-term reliability can be configured.

 [0013] In addition, according to the eccentric weight described in (1) above, since the predetermined thin region and Z or the predetermined hole are provided in the connecting portion for connecting the weight holding portion and the motor shaft holding portion, the eccentric weight is provided. The total weight of the 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.

[0014] According to the eccentric weight described in (2) above, the connecting portion that connects the weight holding portion and the motor shaft holding portion is a single connecting rod when viewed from the direction along the motor shaft. Since it has such a shape, 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 a lighter weight and less power consumption. [0015] In the eccentric weight described in (1) above, the larger the thickness of the thin region and the Z or hole in the connecting portion, the lighter the total weight of the eccentric weight, and There is a benefit that the amount of eccentricity can be increased. On the other hand, if the thin-walled area and the Z or hole size in the connecting part are made too large, the mechanical strength of the connecting part will decrease and the reliability of the eccentric weight will be impaired. Become. Therefore, in the eccentric weight of the present invention, it is preferable to weigh these advantages and disadvantages to determine the thin region and z or hole size in the connection portion.

 [0016] In the eccentric weight described in (2), the total weight of the eccentric weight is reduced and the eccentric weight is reduced as the width of the connecting portion as viewed from the direction along the motor shaft is reduced. The benefit is that the amount of eccentricity can be increased. On the other hand, if the width of the connecting portion is made too thin, the mechanical strength of the connecting portion is lowered, resulting in a disadvantage that the reliability of the eccentric weight is impaired. Therefore, in the eccentric weight of the present invention, it is preferable to determine the width of the connecting portion as viewed from the direction along the motor shaft by weighing these advantages and disadvantages.

 [0017] (3) The eccentric weight of the present invention includes a weight having a high specific gravity metal force, a weight holding part for holding the weight over a half circumference, a motor shaft holding part for holding a motor shaft, and the weight. A weight support body having a structure in which a plurality of thin plate members made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight are stacked, the connecting portion connecting the holding portion and the motor shaft holding portion; The connecting portion of the thin plate member includes a thin region having a thickness smaller than a length along the motor shaft in the motor shaft holding portion and Z or the motor shaft. It is characterized by having holes that open on both sides.

(4) The eccentric weight of the present invention includes a weight having a high specific gravity metal force, a weight holding part for holding the weight over a half circumference, a motor shaft holding part for holding a motor shaft, and the weight A weight support body having a structure in which a plurality of thin plate members made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight are stacked, the connecting portion connecting the holding portion and the motor shaft holding portion; Each connecting portion of the thin plate member has a shape that forms a single connecting rod when viewed from the direction along the motor shaft. It is a sign.

 Therefore, according to the eccentric weight described in the above (3) or (4), the eccentric weight has a specific gravity lower than that of the high specific gravity metal and the high specific gravity metal constituting the weight. Since the eccentric weight includes a weight support body having a structure in which a plurality of thin plate members made of metal are laminated, 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.

 [0020] Further, according to the eccentric weight described in the above (3) or (4), since the weight is held by each weight holding portion in the weight support body over a half circumference, the vibration motor (and the eccentric weight) When the weight is used for a long time, it is possible to suppress a decrease in the reliability of bonding between the weight and the weight support. For this reason, a vibration motor with high long-term reliability can be configured by using such an eccentric weight.

 [0021] Further, according to the eccentric weight described in the above (3), since the predetermined thin area and Z or the predetermined hole are provided in the connecting portion of each thin plate member, the total weight of the eccentric weight is further reduced. At the same time, the amount of eccentricity in the eccentric weight can be further increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter weight and less power consumption.

 [0022] Further, according to the eccentric weight described in the above (4), the connecting portion of each thin plate member is shaped so as to be a single connecting rod when viewed from the direction along the motor shaft. 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.

[0023] In the eccentric weight described in (3) above, the larger the thickness of the thin region and Z or hole in each connecting portion, the lighter the total weight of the eccentric weight and the eccentric weight. The advantage that the amount of eccentricity in can be increased is obtained. On the other hand, if the thickness of the thin area and Z or hole in each connecting part is made too large, the mechanical strength of the connecting part will decrease and the reliability of the eccentric weight may be impaired. It becomes. Therefore, in the eccentric weight of the present invention, these benefits and disadvantages are weighed, It is preferred to determine the thin area and z or hole size at each connection.

 [0024] In the eccentric weight described in (4), the total weight of the eccentric weight is reduced as the width of each connecting portion as viewed from the direction along the motor shaft is reduced. The advantage that the amount of eccentricity in can be increased is obtained. On the other hand, if the width of each connecting portion is made too narrow, the mechanical strength of the connecting portion is lowered, and the disadvantage of deteriorating the reliability of the eccentric weight is caused. Therefore, in the eccentric weight of the present invention, it is preferable to determine the width of each connecting portion in view of the directional force along the motor shaft by weighing these advantages and disadvantages.

 [0025] In the eccentric weight described in (1) -1 (4) above, "half or more" means more than half of the entire circumference of the weight in a plane perpendicular to the longitudinal direction of the weight. The weight may be held in the weight holding portion over the entire length of the weight, but is not necessarily held in the weight holding portion over the entire length of the weight.

 [0026] In the eccentric weight according to any one of (1) and (4), the motor shaft holding portion is a motor shaft holding portion that can hold the motor shaft over the entire circumference. However, the opening force provided on the one side can also hold the motor shaft by, for example, three-way force by caulking and joining the opening after inserting the motor shaft. It may be.

 [0027] (5) In the eccentric weight described in (1) or (3) above, the thin region has a thickness of 50% or less of a length along the motor shaft in the motor shaft holding portion. It is preferable to have

 [0028] With this configuration, the weight of the connecting portion can be sufficiently reduced, so that the total weight of the eccentric weight is further reduced and the amount of eccentricity in the eccentric weight is further increased. Will be able to. 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 even less power consumption.

 [0029] (6) In the eccentric weight described in (1), (3) or (5) above, the thin region preferably has a rib.

[0030] With this configuration, the mechanical strength of the connecting portion can be increased. In addition, a highly reliable vibration motor can be configured. In addition, since the mechanical strength of the connecting portion can be increased, it is possible to further reduce the weight of the connecting portion by enlarging the thin area or hole in the connecting portion. For this reason, the total weight of the eccentric weight can be further reduced, and the eccentric amount of the eccentric weight can be further increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with a lighter and less power consumption.

 [0031] (7) In the eccentric weight according to any one of (1) and (6) above, the thickness of the weight holding portion in the outer peripheral portion that holds the weight on the outer peripheral side of the eccentric weight (of the motor shaft) The thickness in the direction along the radial direction is preferably 0.4 mm or less.

 [0032] With this configuration, the weight can be arranged on the outer peripheral portion as much as possible, and the weight can be made as large as possible. For this reason, the amount of eccentricity in the eccentric weight can be further increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with less power consumption. Speaking of this viewpoint power, the thickness of the weight holding portion in the outer peripheral portion is more preferably 0.3 mm or less, and further preferably 0.2 mm or less.

 (8) In the eccentric weight according to any one of (1) and (7) above, the thickness of the motor shaft holding portion (thickness in the direction along the radial direction of the motor shaft) is: It is preferable to be 4mm or less.

 With such a configuration, 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.

 From this viewpoint, the thickness of the motor shaft holding portion is more preferably 0.3 mm or less, and even more preferably 0.2 mm or less.

 [0035] (9) In the eccentric weight described in (1) or (3), it is preferable that the thin region or the hole is formed by a cutting method!

[0036] With this configuration, the eccentric weight described in (1) or (3) can be manufactured by a relatively simple method. The cutting method is preferably performed using an end mill, for example. Good.

 (10) In the eccentric weight according to any one of (1) and (8) above, it is preferable that the weight support or the thin plate member is manufactured by a metal powder injection molding method. ,.

 [0038] With this configuration, the eccentric weight described in any one of (1) and (8) can be manufactured by a relatively simple method. In this case, the thickness of the weight holding part and motor shaft holding part can be made thinner than that produced by the cutting method. A motor can be configured. In addition, there is an effect that the waste of material is reduced as compared with the case of manufacturing by a cutting method. Furthermore, the effect that the freedom degree of the weight support body and weight in an eccentric weight can be increased is also acquired.

 [0039] (11) In the eccentric weight according to any one of (1) and (8) above, the weight support or the thin plate member is preferably manufactured by a press drawing method. .

 [0040] With this configuration as well, the eccentric weight described in any one of (1) and (8) above can be manufactured by a relatively simple method. In this case, the thickness of the weight holding part and the motor shaft holding part can be made thinner than that produced by the metal fine powder injection molding method, so the required amount of vibration can be reduced with lighter weight and even less power consumption. The resulting vibration motor can be configured. In addition, as compared with the case of manufacturing by a cutting method, there is an effect that material waste is reduced.

 [0041] (12) In the eccentric weight according to any one of (1) and (11) above, it is preferable that the weight is held by the weight holding portion over the entire circumference.

 With this configuration, the weight is held by the weight holding portion in the weight support over the entire circumference. For this reason, when the vibration motor is used for a long time, it is further suppressed that the reliability of the connection between the weight and the weight support is lowered.

 In this case, the “entire circumference” means the entire outer circumference of the weight in a plane perpendicular to the longitudinal direction of the weight.

 (13) In the eccentric weight described in any one of the above (1) and (12), the specific gravity is lower than the high specific gravity metal constituting the weight, and the metal is preferably stainless steel. ,.

[0045] In general, materials constituting weights (for example, tungsten, tungsten alloys, etc.) Since the corrosion resistance tends to be low and it tends to crack, the eccentric weight as a whole has been conventionally made of a material that is highly corrosion resistant and difficult to crack (for example, nickel). However, in such a case, cracks are likely to occur in the joint portion between the eccentric weight and the plating film and in the plating film itself. As a result, cracks are likely to occur due to the cracks. For this reason, there has been a problem that the reliability related to holding the motor shaft in the motor shaft holding portion decreases. On the other hand, stainless steel is originally a material with high corrosion resistance and resistance to cracking, so it is not necessary to apply a plating. For this reason, cracks do not occur at the joint between the eccentric weight and the plating film, and it is possible to suppress a decrease in reliability related to holding the motor shaft in the motor shaft holding portion.

 [0046] In addition, there is a problem that a material constituting the weight (for example, tungsten, tungsten alloy, etc.) is generally fragile and easily broken. On the other hand, since stainless steel is sticky, by holding such a brittle and fragile weight with stainless steel for more than half a circumference, the problem that the material constituting the weight is easily broken is also suppressed.

 [0047] In addition, 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 eccentric weights. On the other hand, since stainless steel is less expensive than tungsten or tungsten alloy, it is possible to reduce the manufacturing cost of eccentric weight by configuring a weight support with such relatively inexpensive stainless steel. become.

 [0048] As the stainless steel, non-magnetic stainless steel can be preferably used in order to reduce the influence on the motor.

 [0049] (14) In the eccentric weight according to any one of the above (1) and (13), the weight is selected from the group consisting of tandasten, tungsten alloy, osmium, osmium alloy, gold, gold alloy, iridium or iridium alloy. I prefer to be.

[0050] With this configuration, tungsten, tungsten alloy, osmium, osmium alloy, gold, gold alloy, iridium or iridium alloy has an extremely high specific gravity, and therefore the amount of eccentricity in the eccentric weight can be further increased. . Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with less power consumption. [0051] 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. Can be used. In addition, it is possible to use a cut body obtained by cutting a sintered body made of a round bar and cutting it into the same cross-sectional shape as that of the weight. In addition, when the cross-sectional shape of the weight is a circle, a sintered body that also has a round bar force can be used as it is cut short.

 [0052] (15) In the eccentric weight according to any one of (1) and (14), 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.

 [0053] With this configuration, the weight can be inserted into any of the end side force weight holding portions, so the degree of freedom when placing the weight in the weight holding portion is increased, and workability is improved. Will improve. For this reason, the manufacturing cost at the time of manufacturing an eccentric weight can be made low.

 [0054] In the eccentric weight described in (15) 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.

 [0055] The eccentric weight of the present invention has a weight inserted into a weight holding portion in a weight support.

It can be manufactured by caulking a weight support.

[0056] Further, the eccentric weight of the present invention can also be manufactured by pressing the weight with a weight holding portion on the weight support in the weight support.

[0057] Further, the eccentric weight of the present invention is a state where the temperature of the weight support is higher than the temperature of the weight.

It can also be manufactured by inserting a weight into a weight holding part in the weight support.

[0058] The eccentric weight of the present invention can also be produced by joining a weight and a weight support. In this case, the joining can be performed by bonding the weight and the weight support, or by brazing the weight and the weight support, or the weight and the weight support can be joined together. It can also be performed by welding. [0059] The eccentric weight of the present invention can be used in combination with the above-described method. For example, it can be manufactured by applying adhesive after crimping, applying adhesive after brazing, spot welding after crimping, or brazing after spot welding, etc. .

 [0060] Regardless of which manufacturing method is used, the weight is held in the weight holding portion over a half circumference, so that the weight is firmly held on the weight support. For this reason, when the vibration motor is used for a long time, the reliability of the connection between the weight and the weight support decreases.

 (16) A vibration motor according to the present invention includes a motor body and the eccentric weight according to any one of (1) and (15) above.

 [0062] Therefore, according to the vibration motor of the present invention, as described above, 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. This is equipped with an excellent eccentric weight that suppresses the decrease in reliability of the connection between the weight and the weight support when the vibration motor is used for a long time. A large amount of vibration can be obtained, and long-term reliability is achieved, resulting in a vibration motor.

 [0063] (17) A portable device of the present invention includes the vibration motor according to (16).

 [0064] 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 vibration motor with high reliability for a long time is provided, light weight and low power consumption are required. A large amount of vibration can be obtained, long-term reliability is high, and it becomes a portable device.

 Brief Description of Drawings

[0065] FIG. 1 is a view for explaining an eccentric weight according to a first embodiment.

 FIG. 2 is a view for explaining the vibration motor according to the first embodiment.

 FIG. 3 is a view for explaining an eccentric weight according to the second embodiment.

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

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

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

FIG. 7 is a view for explaining an eccentric weight according to the sixth embodiment. FIG. 8 is a view for explaining an eccentric weight according to the seventh embodiment.

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

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

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

 FIG. 12 is a view for explaining an eccentric weight according to the tenth embodiment.

 FIG. 13 is a view for explaining an eccentric weight according to the eleventh embodiment.

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

 FIG. 15 is a view for explaining an eccentric weight according to the thirteenth embodiment.

 FIG. 16 is a view for explaining an eccentric weight according to the fourteenth embodiment.

 FIG. 17 is a view for explaining an eccentric weight according to the fifteenth embodiment.

 FIG. 18 is a view for explaining an eccentric weight according to the sixteenth embodiment.

 FIG. 19 is a view for explaining an eccentric weight according to the seventeenth embodiment.

 FIG. 20 is a view for explaining the vibration motor using the eccentric weight according to the seventeenth embodiment.

 FIG. 21 is a view for explaining a conventional vibration motor and an eccentric weight.

 FIG. 22 is a view for explaining another conventional eccentric weight.

 BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the eccentric weight, the manufacturing method thereof, the vibration motor, and the 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 according to the first embodiment. Fig. 1 (a) is a front view of the eccentric weight according to Embodiment 1, and Fig. 1 (b) is a schematic view of the eccentric weight according to Embodiment 1 as viewed from the front. ) Is a cross-sectional view taken along the line A-A in FIG. 1 (a), FIG. 1 (d) is a cross-sectional view taken along the line B-B in FIG. 1 (a), and FIG. 1 (e) is a cross-sectional view of the eccentric weight according to the first embodiment. FIG. 1 (f) is a perspective view of the eccentric weight according to Embodiment 1 as seen from the rear side force in FIG. 1 (e).

As shown in FIG. 1, the eccentric weight 120 according to the first embodiment has a substantially fan-shaped cross section. Copper 140 and weight support 130 are provided. Weight 140 also has high specific gravity metal power. The weight support body 130 also has a metal force having a specific gravity lower than that of the high specific gravity metal constituting the weight 140. The weight support body 130 includes a weight holding portion 134 for holding the weight 140 over the entire circumference and a motor shaft holding portion 132 for holding the motor shaft 11 2 (see FIG. 2), the weight holding portion 134 and the motor. It has a connecting part 136 (the part shaded in FIG. 1 (b)) for connecting the shaft holding part 132. The connecting part 136 is located between the weight holding part 134 and the motor shaft holding part 132. The connecting portion 136 has a thin region 138 that opens to one side along the motor shaft 112.

 [0069] Therefore, according to the eccentric weight 120 according to the first embodiment, the eccentric weight includes the weight 140 made of a high specific gravity metal and the weight support having a lower specific gravity than the high specific gravity metal constituting the weight 140. Thus, the total weight of the eccentric weight 120 can be reduced and the amount of eccentricity of 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, the weight 140 is held by the weight holding portion 134 of the weight support 130 over the entire circumference, so that the vibration motor (and the eccentric weight 120) is also provided. ) Is used for a long time, it is possible to prevent the reliability of bonding between the weight 140 and the weight support 130 from being lowered. Therefore, by using such an eccentric weight 120, it is possible to configure a vibration motor with high long-term reliability.

 In addition, according to the eccentric weight 120 according to the first embodiment, the predetermined thin region 138 is provided in the connecting portion 136 that connects the weight holding portion 134 and the motor shaft holding portion 132. The total weight can be reduced and the amount of eccentricity in the eccentric weight can be further increased. Therefore, by using such an eccentric weight, it is possible to configure a vibration motor that can obtain a necessary vibration amount with a lighter and less power consumption.

[0072] It should be noted that a hole having a shape corresponding to the cross-sectional shape of the weight 140 is formed in the weight support 130 to hold the weight 140, but in the eccentric weight 120 according to the first embodiment, the hole is formed. The portion around this hole is called a weight holding portion 134. Further, the weight support 130 has a hole having a shape corresponding to the cross-sectional shape of the motor shaft 112 in order to hold the motor shaft 112. However, in the eccentric weight 120 according to the first embodiment, a portion around this hole is referred to as a motor shaft holding portion 132. Therefore, the connecting portion 136 connects the weight holding portion 134 and the motor shaft holding portion 132 as shown in FIG. 1 (b).

 In the eccentric weight 120 according to the first embodiment, “the entire circumference” is the entire outer periphery of the weight 140 in a plane perpendicular to the longitudinal direction of the weight 140.

 In the eccentric weight 120 according to the first embodiment, as shown in FIGS. 1 (c) and 1 (d), along the motor shaft 112 in the weight 140 (along the longitudinal direction of the weight 140). The length is 4mm. Further, the length along the motor shaft 112 in the weight holder 134 of the weight support 130 is 2 mm, and the length along the motor shaft 112 in the motor shaft holder 132 of the weight support 130 is also 2 mm. Further, the thickness (thickness in the direction along the motor shaft 112) of the thin region 138 in the connecting portion 136 of the weight support 130 is 0.2 mm.

 For this reason, in the eccentric weight 120 according to the first embodiment, the weight 140 has a weight support 130 in a half length (2 mm) of the length (4 mm) along the length direction of the weight 140. Is held by the weight holder 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, the thin region 138 has a thickness that is 10% of the length along the motor shaft 112 in the motor shaft holding portion 132. In other words, the thin wall region 138 has a shape in which a portion having a depth of 1.8 mm is removed by cutting, so that the weight of the connecting portion 136 can be sufficiently reduced, and an eccentric weight is obtained. The total weight of 120 can be further reduced, and the eccentric amount of 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 lighter and less power consumption.

 In the eccentric weight 120 according to the first embodiment, the thickness in the radial direction of the motor shaft 112 of the weight holding portion 134 in the outer peripheral portion that holds the weight 140 from the outer peripheral side of the eccentric weight 120. Is 0.25 mm.

For this reason, in the eccentric weight 120 according to the first embodiment, the weight 140 can be arranged on the outer peripheral portion as much as possible, and the weight 140 can be made as large as possible. The amount of eccentricity at 20 can be further 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 less power consumption.

 In the eccentric weight 120 according to the first embodiment, the thickness of the motor shaft holder 132 in the direction along the radial direction of the motor shaft 112 is 0.2 mm.

 Therefore, in the eccentric weight 120 according to the first embodiment, the total weight of the eccentric weight 120 can be further 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 configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

 In the eccentric weight 120 according to the first embodiment, as shown in FIG. 1, the weight 140 has a substantially fan-shaped cross section, and includes a predetermined first weight including the central axis of the motor shaft holding portion 132. It has a plane-symmetric shape with a plane (indicated by A–A in Fig. 1 (a)) as a plane of symmetry.

 [0082] Therefore, in the eccentric weight 120 according to the first embodiment, the weight 140 is inserted into any end portion (see the end portions S and S shown in FIG. 1 (c). The M-law force is also inserted into the weight holding portion 134. Can also

 1 2

 Therefore, the degree of freedom when placing the weight 140 on the weight holding portion 134 is increased, and the workability is improved. For this reason, the manufacturing cost at the time of manufacturing the eccentric weight 120 can be made low.

 Here, “the central axis of the motor shaft holding portion 132” means that the central axis of the motor shaft 112 is located when the motor shaft holding portion 132 holds the motor shaft 112 (see FIG. 2). It is the axis that will be.

 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 a molten stainless steel having a specific gravity lower than that of the tungsten alloy.

[0085] For this reason, since the weight support 130 also has a stainless steel strength of a molten material having a specific gravity lower than that of the tungsten sintered alloy constituting the weight 140, the weight support 130 is improved in durability and the weight support 130 is improved. And the weight 140 can be integrated more firmly, and the reliability of the connection between the weight 140 and the weight support 1 30 is reduced when the vibration motor (and the eccentric weight 120) is used for a long time. This is further suppressed. For this reason, such eccentricity By using copper 120, a vibration motor with high long-term reliability can be configured.

[0086] Since stainless steel is originally a material with high corrosion resistance and resistance to rust, it is not necessary to apply a plating even if it is used as a weight support. As a result, cracks do not occur at the joint between the weight support 130 and the plating film and the plating film itself, and no cracks are generated due to cracks, etc. It is suppressed that the reliability regarding the holding of the motor shaft 112 in 132 is lowered.

[0087] Further, since stainless steel is sticky, it is brittle and easily broken like a tungsten alloy! By holding the weight with sticky stainless steel over the entire circumference, the problem that the weight is easily cracked is also suppressed.

 [0088] Further, since stainless steel is less expensive than tungsten alloy and the like, the weight support body 130 is made of such a relatively inexpensive stainless steel, thereby reducing the manufacturing cost of the eccentric weight 120. Becomes easier.

 [0089] In the eccentric weight 120 according to the first embodiment, the thin region 138 is formed by a cutting method. For this reason, the eccentric weight 120 according to Embodiment 1 can be manufactured by a relatively simple method. The cutting method is performed using, for example, an end mill.

 [0090] In the eccentric weight 120 according to the first embodiment, the weight 140 also has a tungsten alloy force. 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.

 Note that, 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 weight is extremely simple (substantially fan-shaped). Adopting a bar shape with a cross section.).

[0092] 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 The manufacturing method is to make a round bar with a simple shape by sintering and then cut out the round bar to make a weight of 140. By doing so, the amount of the additive (for example, copper) contained in the tandastain 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. I can do it The

 [0093] The eccentric weight 120 according to Embodiment 1 can be manufactured, for example, by the following method.

 (1) A member having a shape corresponding to the weight support 130 is manufactured by a press working method (however, the thin region 138 and the motor shaft holding portion 132 are not formed).

 (2) The weight support body 130 is manufactured by forming the thin region 138 and the motor shaft holding portion 132 on this member by a cutting method.

 (3) A tungsten alloy round bar having a cross section larger than that of the weight 140 is prepared.

 (4) Next, the outer circumference of the round bar described above is cut to produce a bar having a cross-sectional shape corresponding to the cross-sectional shape of the weight 140.

 (5) Next, the above-described bar is cut into a predetermined length to produce a weight 140.

 [0096] (6) The weight support 134 is held by the weight support 134 by caulking the weight support 130 from the outside in a state where the weight 140 is inserted into the weight holding part 134 of the weight support 130.

(7) Thereby, the eccentric weight 120 in which the weight 140 is held by the weight holding portion 134 in the weight support 130 is manufactured over the entire circumference.

With this method, the weight 140 is held firmly by the weight holding portion 134 in the weight support 130 over the entire circumference, so that the vibration motor (and the eccentric weight 1

When 20) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight 140 and the weight support 130.

FIG. 2 is a view for explaining the vibration motor according to the first embodiment. Fig. 2 (a) is a perspective view of the vibration motor according to Embodiment 1, Fig. 2 (b) is a view of the vibration motor according to Embodiment 1, and Fig. 2 (c) is the embodiment. 1 is a side view of a part of a vibration motor according to 1. FIG.

The vibration motor 100 according to the first embodiment is a vibration motor including a motor body 110 and an eccentric weight 120. Further, as described above, 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. Weight and weight when the motor is used for a long time An excellent eccentric weight 120 is provided in which deterioration of the reliability of bonding with the support is suppressed. For this reason, the vibration motor 100 according to the first embodiment is a vibration motor having such an excellent eccentric weight 120. Therefore, a required amount of vibration can be obtained with light weight and low power consumption, and long-term reliability can be obtained. High vibration motor.

[0100] For this reason, by using the vibration motor 100 that is light and has a small amount of vibration with low power consumption and has high reliability for a long time as a vibration motor for portable devices, It can be a highly portable device that is lightweight, has low power consumption, and is reliable for a long time.

 [Embodiment 2]

 FIG. 3 is a view for explaining the eccentric weight according to the second embodiment. Fig. 3 (a) is a front view of the eccentric weight according to Embodiment 2, and Fig. 3 (b) is an AA cross-sectional view of Fig. 3 (a).

 [0102] The eccentric weight 220 according to the second embodiment basically has the same structure as the eccentric weight 120 according to the first embodiment. However, the eccentric weight 220 according to the second embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 230 as shown in FIG. That is, in the eccentric weight 220 according to the second embodiment, the connecting portion 236 of the weight support 230 has a thin region 238 that opens on both sides along the motor shaft.

 [0103] As described above, the eccentric weight 220 according to the second embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 230, but the eccentric weight is divided into components having high specific gravity metal force. Since the eccentric weight 220 is provided with the copper 240 and the weight support body 230 made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 240, the eccentric weight is the same as in the case of the eccentric weight 120 according to the first embodiment. The total weight of the weight 220 can be reduced and the amount of eccentricity in the eccentric weight 220 can be increased. Therefore, by using such an eccentric weight 220, it is possible to configure a vibration motor that can obtain a large amount of vibration with light weight and low power consumption.

[0104] Also, according to the eccentric weight 220 according to the second embodiment, the weight 240 is held by the weight holding portion 234 in the weight support body 230 over the entire circumference, so the eccentric weight according to the first embodiment. As in the case of 120, when the eccentric weight 220 is used for a long time, it is possible to prevent the reliability of the connection between the weight 240 and the weight support 230 from being lowered. For this reason, By using the eccentric weight 220, a vibration motor with high long-term reliability can be configured.

 In addition, according to the eccentric weight 220 according to the second embodiment, the predetermined thin region 238 is provided in the connecting portion 236 that connects the weight holding portion 234 and the motor shaft holding portion 232. As in the case of the eccentric weight 120 according to the above, the total weight of the eccentric weight 220 can be reduced and the amount of eccentricity in the eccentric weight 220 can be further increased. For this reason, by using such an eccentric weight 220, it is possible to configure a vibration motor that can obtain a necessary vibration amount with a lighter and less power consumption.

 [Embodiment 3]

 FIG. 4 is a view for explaining the eccentric weight according to the third embodiment. 4 (a) is a front view of the eccentric weight according to Embodiment 3, and FIG. 4 (b) is a cross-sectional view taken along line AA in FIG. 4 (a).

 The eccentric weight 320 according to the third embodiment has basically the same structure as the eccentric weight 120 according to the first embodiment. However, the eccentric weight 320 according to the third embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 330 as shown in FIG. That is, in the eccentric weight 320 according to the third embodiment, the connecting portion 336 of the weight support 330 has holes 338 that are open on both sides along the motor shaft.

 As described above, the eccentric weight 320 according to the third embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 330, but the eccentric weight is used as a component having a high specific gravity metal force. Since the eccentric weight 320 is provided with the copper 340 and the weight support body 330 made of a low density metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 340, the eccentric weight is the same as in the case of the eccentric weight 120 according to the first embodiment. The total weight of the weight 320 can be reduced and the amount of eccentricity of the eccentric weight 320 can be increased. For this reason, by using such an eccentric weight 320, it is possible to configure a vibration motor that can obtain a large vibration amount with light weight and low power consumption.

[0109] Also, according to the eccentric weight 320 according to the third embodiment, the weight 340 is held by the weight holding portion 334 in the weight support body 330 over the entire circumference, so the eccentric weight according to the first embodiment. As in the case of 120, when the eccentric weight 320 is used for a long time, it is possible to suppress a decrease in the reliability of bonding between the weight 340 and the weight support 330. For this reason, By using the eccentric weight 320, a vibration motor with high long-term reliability can be configured.

 [0110] Further, according to the eccentric weight 320 according to the third embodiment, the predetermined hole 338 is provided in the connecting portion 336 that connects the weight holding portion 334 and the motor shaft holding portion 332, and therefore, according to the first embodiment. As in the case of the eccentric weight 120, the total weight of the eccentric weight 320 can be reduced and the amount of eccentricity in the eccentric weight 320 can be further increased. Therefore, by using such an eccentric weight 320, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

 [Embodiment 4]

 FIG. 5 is a view for explaining the eccentric weight according to the fourth embodiment. FIG. 5 (a) is a front view of the eccentric weight according to Embodiment 4, and FIG. 5 (b) is an AA cross-sectional view of FIG. 5 (a).

 [0112] The eccentric weight 420 according to the fourth embodiment has basically the same structure as the eccentric weight 120 according to the first embodiment. However, the eccentric weight 420 according to the fourth embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 430, as shown in FIG. That is, in the eccentric weight 420 according to the fourth embodiment, the connecting portion 436 of the weight support 430 has a shape that forms a single connecting rod when viewed from the direction along the motor shaft. .

 [0113] As described above, the eccentric weight 420 according to the fourth embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support body 430, but the eccentric weight is divided into components having high specific gravity metal force. Since the eccentric weight 420 is provided with the copper 440 and the weight support body 430 made of a low weight metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 440, the eccentric weight is the same as in the case of the eccentric weight 120 according to the first embodiment. While reducing the total weight of the weight 420, the amount of eccentricity in the eccentric weight 420 can be increased. For this reason, by using such an eccentric weight 420, it is possible to configure a vibration motor that can obtain a large vibration amount with light weight and low power consumption.

[0114] Furthermore, according to the eccentric weight 420 according to the fourth embodiment, the weight 440 is held by the weight holding portion 434 in the weight support body 430 over the entire circumference, and therefore the eccentric weight according to the first embodiment. As in the case of 120, when the eccentric weight 420 is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight 440 and the weight support 430. For this reason, By using the eccentric weight 420, a vibration motor with high long-term reliability can be configured.

 [0115] Further, according to the eccentric weight 420 according to the fourth embodiment, the connecting portion 436 that connects the weight holding portion 434 and the motor shaft holding portion 432 is formed with a single connecting rod by looking at the directional force along the motor shaft. Therefore, the total weight of the eccentric weight 420 can be reduced and the amount of eccentricity in the eccentric weight 420 can be further increased. For this reason, the use of such an eccentric weight 420 makes it possible to construct a vibration motor that can obtain the required amount of vibration with a lighter weight and less power consumption, as in the case of the eccentric weight 120 according to the first embodiment. can do.

 [Embodiment 5]

 FIG. 6 is a view for explaining the eccentric weight according to the fifth embodiment. FIG. 6 (a) is a front view of the eccentric weight according to Embodiment 5, and FIG. 6 (b) is an AA cross-sectional view of FIG. 6 (a).

 [0117] The eccentric weight 520 according to the fifth embodiment has basically the same structure as the eccentric weight 120 according to the first embodiment. However, as shown in FIG. 6, the eccentric weight 520 according to the fifth embodiment has the shape of the weight 540 (and the shape of the weight holding portion 534 in the weight support 530) as shown in FIG. It is different from the case of. That is, in the eccentric weight 520 according to the fifth embodiment, the weight 540 has an oval shape.

 As described above, the eccentric weight 520 according to the fifth embodiment has the shape of the weight 540 (and the shape of the weight holding portion 534 in the weight support 530) corresponding to the eccentric weight 120 according to the first embodiment. Because the eccentric weight is an eccentric weight 520 having a weight 540 made of a high specific gravity metal and a weight support 530 made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 540, As in the case of the eccentric weight 120 according to the first embodiment, the total weight of the eccentric weight 520 can be reduced and the amount of eccentricity in the eccentric weight 520 can be increased. Therefore, by using such an eccentric weight 520, it is possible to configure a vibration motor that can obtain a large vibration amount with light weight and low power consumption.

[0119] Also, according to the eccentric weight 520 according to the fifth embodiment, the weight 540 is held by the weight holding portion 534 in the weight support body 530 over the entire circumference, and therefore the eccentric weight according to the first embodiment. As with 120, if the vibration motor (and eccentric weight 520) is used for a long time, In this case, it is possible to suppress a decrease in the reliability of joining between the weight 540 and the weight support 530. Therefore, by using such an eccentric weight 520, it is possible to configure a vibration motor with high long-term reliability.

 [0120] Also, according to the eccentric weight 520 according to the fifth embodiment, the predetermined thin region 538 is provided in the connecting portion 536 that connects the weight holding portion 534 and the motor shaft holding portion 532, so that Embodiment 1 As in the case of the eccentric weight 120 according to the above, the total weight of the eccentric weight 520 can be reduced and the amount of eccentricity in the eccentric weight 520 can be further increased. For this reason, by using such an eccentric weight 520, it is possible to configure a vibration motor that can obtain a required vibration amount with lighter and less power consumption.

 [Embodiment 6]

 FIG. 7 is a view for explaining the eccentric weight according to the sixth embodiment. FIG. 7 (a) is a front view of the eccentric weight according to Embodiment 6, and FIG. 7 (b) is an AA cross-sectional view of FIG. 7 (a).

 [0122] The eccentric weight 620 according to the sixth embodiment has basically the same structure as the eccentric weight 120 according to the first embodiment. However, the eccentric weight 620 according to the sixth embodiment is different from the eccentric weight 120 according to the first embodiment in the shape of the weight support 630 as shown in FIG. That is, in the eccentric weight 620 according to the sixth embodiment, the weight support 630 serves as the weight holding portion instead of the weight holding portion that holds the weight over the entire circumference, and covers the entire outer periphery of the weight 640. There is a weight holding part 634 for holding the weight 640 over a half circumference.

 [0123] As described above, the eccentric weight 620 according to the sixth embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 630, but the eccentric weight is divided into components having high specific gravity metal force. Since the eccentric weight 620 includes the copper 640 and the weight support body 630 made of a low weight metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 640, the eccentric weight 120 is the same as in the case of the eccentric weight 120 according to the first embodiment. The total weight of the weight 620 can be reduced and the amount of eccentricity in the eccentric weight 620 can be increased. Therefore, by using such an eccentric weight 620, it is possible to configure a vibration motor that can obtain a large amount of vibration with light weight and low power consumption.

[0124] Further, according to the eccentric weight 620 according to the sixth embodiment, the weight 640 is held by the weight holding portion 634 in the weight support 630 over more than half a circumference. As in the case of the eccentric weight 120, the deterioration of the bonding reliability between the weight 640 and the weight support 630 is suppressed when the vibration motor (and the eccentric weight 620) is used for a long time. Therefore, by using such an eccentric weight 620, a vibration motor with high long-term reliability can be configured.

 [0125] Also, according to the eccentric weight 620 according to the sixth embodiment, the predetermined thin region 638 is provided in the connecting portion 636 that connects the weight holding portion 634 and the motor shaft holding portion 632, so that Embodiment 1 As in the case of the eccentric weight 120 according to the above, the total weight of the eccentric weight 620 can be 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 configure a vibration motor that can obtain a necessary vibration amount with lighter and even less power consumption.

 [0126] The width L of the opening in the weight holding portion 634 is in the width direction of the opening in the weight 640.

 2

 It is set narrower than the maximum parallel length L. For this reason, the weight 640 is firmly held by the weight holding portion 634.

[Embodiment 7]

 FIG. 8 is a view for explaining the eccentric weight according to the seventh embodiment. FIG. 8 (a) is a front view of the eccentric weight according to Embodiment 7, and FIG. 8 (b) is an AA cross-sectional view of FIG. 8 (a).

 The eccentric weight 720 according to the seventh embodiment basically has the same structure as the eccentric weight 120 according to the first embodiment. However, the eccentric weight 720 according to the seventh embodiment is different from the eccentric weight 120 according to the first embodiment in the structure of the weight support 730 as shown in FIG. That is, in the eccentric weight 720 according to the seventh embodiment, the weight support 730 replaces the motor shaft holding portion that holds the motor shaft over the entire circumference as the motor shaft holding portion. A motor shaft holding portion 732 that also holds a three-way force is provided. After the motor shaft is inserted into the motor shaft holding portion 732, the opening is forced and held by the weight support 730 with tension.

As described above, the eccentric weight 720 according to the seventh embodiment is different from the eccentric weight 120 according to the first embodiment in that the structure of the weight support 730 is different from that of the eccentric weight 120 according to the first embodiment. Weight support made of copper 740 and a low-density metal with a specific gravity higher than that of the high specific gravity metal that composes weight 740 Since the eccentric weight 720 including the body 730 is used, as in the case of the eccentric weight 120 according to the first embodiment, the total weight of the eccentric weight 720 can be reduced and the amount of eccentricity in the eccentric weight 720 can be increased. Therefore, by using such an eccentric weight 720, it is possible to configure a vibration motor that can obtain a large amount of vibration with light weight and low power consumption.

[0130] Also, according to the eccentric weight 720 according to the seventh embodiment, the weight 740 is held by the weight holding portion 734 in the weight support body 730 over the entire circumference, and therefore the eccentric weight according to the first embodiment. As in the case of 120, when the vibration motor (and the eccentric weight 720) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight 740 and the weight support 730. Therefore, by using such an eccentric weight 720, a vibration motor with high long-term reliability can be configured.

 [0131] Furthermore, according to the eccentric weight 720 according to the seventh embodiment, the predetermined thin region 738 is provided in the connecting portion 736 that connects the weight holding portion 734 and the motor shaft holding portion 732, so that the first embodiment 1 Similarly to the case of the eccentric weight 120 according to the above, the total weight of the eccentric weight 720 can be reduced and the amount of eccentricity in the eccentric weight 720 can be further increased. Therefore, by using such an eccentric weight 720, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

 [Embodiment 8]

 FIG. 9 is a view for explaining the eccentric weight according to the eighth embodiment. Fig. 9 (a) is a diagram of the eccentric weight according to Embodiment 8 as viewed from the front, and Fig. 9 (b) is a schematic diagram of the eccentric weight according to Embodiment 8 as viewed from the front. ) Is a cross-sectional view taken along the line A-A in FIG. 9 (a), FIG. 9 (d) is a cross-sectional view taken along the line BB in FIG. 9 (a), and FIG. 9 (e) is a cross-sectional view of the eccentric weight according to the eighth embodiment. FIG. 9 (f) is a perspective view of the eccentric weight according to Embodiment 8 as seen from the rear side force in FIG. 9 (e).

[0133] The eccentric weight 820 according to the eighth embodiment basically has the same structure as the eccentric weight 420 according to the fourth embodiment. However, the eccentric weight 820 according to the eighth embodiment is different from the eccentric weight 420 according to the fourth embodiment in the method of manufacturing the weight support 830. That is, in the eccentric weight 820 according to Embodiment 8, the weight support 830 is manufactured by the metal powder injection molding method. As described above, the eccentric weight 820 according to the eighth embodiment is different from the eccentric weight 420 according to the fourth embodiment in the manufacturing method of the weight support 830, but the eccentric weight is made of a high specific gravity metal. In the same way as the eccentric weight 420 according to the fourth embodiment, the eccentric weight 820 is provided with the weight 840 and the weight support 830 made of a metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 840. The total weight of the eccentric weight 820 can be reduced and the amount of eccentricity in the eccentric weight 820 can be increased. For this reason, by using such an eccentric weight 820, it is possible to configure a vibration motor that can obtain a large amount of vibration with light weight and low power consumption.

 In addition, according to the eccentric weight 820 according to the eighth embodiment, the weight 840 is held by the weight holding portion 834 in the weight support 830 over the entire circumference, so that the eccentric weight according to the fourth embodiment. As in the case of 420, when the vibration motor (and the eccentric weight 820) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight 840 and the weight support 830. Therefore, by using such an eccentric weight 820, a vibration motor with high long-term reliability can be configured.

 [0136] Also, according to the eccentric weight 820 according to the eighth embodiment, the connecting portion 836 for connecting the weight holding portion 834 and the motor shaft holding portion 832 has a single connecting rod and a directional force along the motor shaft. Therefore, as in the case of the eccentric weight 420 according to the fourth embodiment, the total weight of the eccentric weight 820 can be reduced and the amount of eccentricity in the eccentric weight 820 can be further increased. For this reason, by using such an eccentric weight 820, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

 [0137] Further, according to the eccentric weight 820 according to the eighth embodiment, since it is manufactured by the metal powder injection molding method, it is manufactured by the cutting method as in the case of the eccentric weight 420 according to the fourth embodiment. Rather than that, the thickness of the weight holding part 834 and the motor shaft holding part 832 can be reduced, and a vibration motor that can obtain the necessary vibration amount with lighter and less power consumption can be configured. Therefore, in the eccentric weight 820 according to the eighth embodiment, as shown in FIG. 9C, the thicknesses of the weight holding portion 834 and the motor shaft holding portion 832 are 0.15 mm.

Further, according to the eccentric weight 820 according to the eighth embodiment, when manufactured by a cutting method As compared with the above, an effect that the waste of the material is reduced can be obtained.

 Furthermore, according to the eccentric weight 820 according to the eighth embodiment, there is an effect that the degree of freedom of the shape of the weight support 830 and the weight 840 in the eccentric weight 820 can be increased.

[Embodiment 9]

 FIG. 10 is a view for explaining the eccentric weight according to the ninth embodiment. Fig. 10 (a) is a diagram of the eccentric weight according to Embodiment 9 as viewed from the front, and Fig. 10 (b) is a schematic diagram of the eccentric weight according to Embodiment 9 as viewed from the front. Fig. 10 (a) is a cross-sectional view taken along the line A-A, Fig. 10 (d) is a cross-sectional view taken along the line BB of Fig. 10 (a), and Fig. 10 (e) is a perspective view of the eccentric weight according to the ninth embodiment. FIG. 10 (f) is a perspective view of the eccentric weight according to Embodiment 9 as seen from the back side of FIG. 10 (e).

 FIG. 11 is a view for explaining the manufacturing method for manufacturing the eccentric weight according to the ninth embodiment. FIG. 11 (a) -FIG. 11 (f) are diagrams showing the main part in the manufacturing process.

[0139] The eccentric weight 920 according to the ninth embodiment is different from the eccentric weight 120, 820 according to the first or eighth embodiment in the method of manufacturing the weight support 930. That is, in the eccentric weight 920 according to the ninth embodiment, the weight support 930 is manufactured by a press drawing method.

 [0140] The eccentric weight 920 according to the ninth embodiment is manufactured by the following process.

 [0141] (1) Work placement

 First, a workpiece W made of stainless steel having a thickness of 0.5 mm is disposed at a predetermined position between a die plate 962 in the die for press drawing and a punch plate 972 in the punch die ( (See Figure 11 (a).)

 [0142] (2) Press drawing

Next, the punching die (and punch 974) is lowered toward the workpiece W, and a portion corresponding to the thin region 938 in the motor shaft holding portion 932 and a portion corresponding to the hole in the weight holding portion 934 are formed. Plastically deform. At this time, the portion constituting the motor shaft holding portion 932 and the portion constituting the weight holding portion 934 are also plastically deformed and extend downward in the drawing (FIG. 11 (b) —FIG. 11). See (d);). This press drawing process can be performed by performing a single press, and the die mold 960 and the punch mold 970 must not be replaced. Force Can also be done by pressing multiple times.

 [0143] (3) Removal of unnecessary parts

Next, remove the workpiece W from the press stop device 950, is removed by cutting the unnecessary parts min in weight support (see FIG. 11 (e) and FIG. 11 (f).) ₀ in this case, unnecessary portions Cut along the broken lines L, L, L in Fig. 11 (e).

 one two Three

 Perform multiple times along. Thereby, the weight support body 930 is manufactured. In addition, you may cut an unnecessary part along the up-down direction of drawing using a press force grinder.

 As described above, the eccentric weight 920 according to the ninth embodiment is different from the eccentric weight 120, 820 according to the first or eighth embodiment in that the method of manufacturing the weight support 930 is different from the eccentric weight 120, 820 in the high specific gravity. Since the eccentric weight 920 includes a weight 940 made of a metal and a weight support 930 made of a low weight metal having a specific gravity lower than that of the high specific gravity metal constituting the weight 940, the eccentric weight 120 according to the first or eighth embodiment 120, As in the case of 820, the total weight of the eccentric weight 920 can be reduced and the amount of eccentricity in the eccentric weight 920 can be increased. Therefore, by using such an eccentric weight 920, it is possible to configure a vibration motor that can obtain a large vibration amount with light weight and low power consumption.

 [0145] Further, according to the eccentric weight 920 according to the ninth embodiment, the weight 940 is held by the weight holding portion 934 in the weight support body 930 over the entire circumference, so that the eccentric weight according to the first or eighth embodiment is used. As in the case of the weights 120 and 820, when the vibration motor (and the eccentric weight 920) is used for a long time, it is possible to suppress a decrease in the reliability of the connection between the weight 940 and the weight support 930. Therefore, by using such an eccentric weight 920, a vibration motor with high long-term reliability can be configured.

 Further, according to the eccentric weight 920 according to the ninth embodiment, the predetermined thin region 938 is provided in the connecting portion 936 that connects the weight holding portion 934 and the motor shaft holding portion 932. Alternatively, as in the case of the eccentric weights 120 and 820 according to 8, the total weight of the eccentric weight 920 can be reduced and the amount of eccentricity in the eccentric weight 920 can be further increased. Therefore, by using such an eccentric weight 920, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

[0147] Further, according to the eccentric weight 920 according to the ninth embodiment, the eccentric weight according to the first or eighth embodiment. As in the case of 120, 820, the thickness of the weight holding part and the motor shaft holding part can be made thinner than that produced by the cutting method or metal powder injection molding method. It is possible to configure a vibration motor that can obtain the required amount of vibration with electric power. Therefore, in the eccentric weight 920 according to the ninth embodiment, as shown in FIG. 10 (c), the thickness of the weight holding part 934 and the motor shaft holding part 932 is 0.15 mm.

 Further, according to the eccentric weight 920 according to the ninth embodiment, an effect that the waste of material is reduced as compared with the case of manufacturing by a cutting method is also obtained.

[Embodiment 10]

 FIG. 12 is a view for explaining the eccentric weight according to the tenth embodiment. FIG. 12 (a) is a view of the eccentric weight according to Embodiment 10 as viewed from the front, and FIG. 12 (b) is a cross-sectional view taken along line AA in FIG. 12 (a).

 [0149] The eccentric weight 1020 according to the tenth embodiment basically has the same structure as the eccentric weight 920 according to the ninth embodiment. However, the eccentric weight 1020 according to the tenth embodiment is different from the eccentric weight 920 according to the ninth embodiment in the structure of the weight support 1030 as shown in FIG. That is, in the eccentric weight 1020 according to the tenth embodiment, as shown in FIG. 12B, ribs 1039 are formed in the thin region 1038 of the connecting portion 1036 in the weight support 1030.

 [0150] For this reason, in the eccentric weight 1020 according to the tenth embodiment, the mechanical strength of the connecting portion 1036 can be increased, so that a more reliable vibration motor can be configured. In addition, since the mechanical strength of the connecting portion 1036 can be increased, the thin area 1038 of the connecting portion 1036 can be enlarged to further reduce the weight of the connecting portion 1036. Therefore, the total weight of the eccentric weight 1020 can be further reduced, and the amount of eccentricity in the eccentric weight 1020 can be further increased. Therefore, by using such an eccentric weight 1020, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter and less power consumption.

[0151] The eccentric weight 1020 according to the tenth embodiment has the same configuration as the eccentric weight 920 according to the ninth embodiment except for the above, and thus the eccentric weight 920 according to the ninth embodiment is provided. It has the effect to do as it is.

 [Embodiment 11]

 FIG. 13 is a view for explaining the eccentric weight according to the eleventh embodiment. FIG. 13 (a) is a view of the eccentric weight according to the eleventh embodiment as viewed from the front, and FIG. 13 (b) is a cross-sectional view taken along the line AA in FIG. 13 (a).

 [0153] The eccentric weight 1120 according to the eleventh embodiment basically has the same structure as the eccentric weight 920 according to the ninth embodiment. However, the eccentric weight 1120 according to the eleventh embodiment is different from the eccentric weight 920 according to the ninth embodiment in the structure of the weight support 1130 as shown in FIG. That is, in the eccentric weight 1120 according to the eleventh embodiment, a hole 1138 is formed in the connecting portion 1136 in the weight support 1130.

 [0154] Therefore, in the eccentric weight 1120 according to the eleventh embodiment, the weight of the connecting portion 1130 can be further reduced. Therefore, the total weight of the eccentric weight 1120 can be further reduced, and the amount of eccentricity in the eccentric weight 1120 can be further increased. Therefore, by using such an eccentric weight 1120, it is possible to configure a vibration motor that can obtain a necessary vibration amount with a lighter and less power consumption.

 Note that the eccentric weight 1120 according to the eleventh embodiment has the same configuration as the eccentric weight 920 according to the ninth embodiment except for the above, and therefore the eccentric weight 920 according to the ninth embodiment is provided. It has the effect to do as it is.

 [Embodiment 12-15]

 FIG. 14 is a view for explaining the eccentric weight according to the twelfth embodiment. FIG. 14 (a) is a view of the eccentric weight according to the twelfth embodiment as viewed from the front, and FIG. 14 (b) is a cross-sectional view taken along line AA in FIG. 14 (a).

 FIG. 15 is a view for explaining the eccentric weight according to the thirteenth embodiment. FIG. 15 (a) is a diagram of the eccentric weight according to the thirteenth embodiment as viewed from the front, and FIG. 15 (b) is a cross-sectional view taken along the line AA in FIG. 15 (a).

FIG. 16 is a view for explaining the eccentric weight according to the fourteenth embodiment. FIG. 16 (a) is a view of the eccentric weight according to the embodiment 14 as viewed from the front, and FIG. 16 (b) is a cross-sectional view taken along line AA in FIG. 16 (a). FIG. 17 is a view for explaining the eccentric weight according to the fifteenth embodiment. FIG. 17 (a) is a view of the eccentric weight according to the fifteenth embodiment as viewed from the front, and FIG. 17 (b) is a cross-sectional view taken along line AA in FIG. 17 (a).

 [0157] Deviations according to Embodiments 12-15, weights 1220, 1320, 1420, 1520ί, and weights having a structure in which a plurality of thin plate members are laminated as weight support members as shown in FIG. This is different from the case of the eccentric weight 120-1120 according to Embodiments 1-11 in that the support body is used.

 [0158] According to the eccentric force S, et al., The weights 1220, 1320, 1420, and 1520 according to the embodiments 12-15, the eccentric weight is composed of the weight of the high specific gravity metal and the weight. In the case of the eccentric weight 120-1120 according to the embodiment 11-11, the eccentric weight includes a weight support body having a structure in which a plurality of thin plate members made of a metal having a specific gravity lower than that of the high specific gravity metal is laminated. Similarly, it is possible to reduce the total weight of the eccentric weight and increase the amount of eccentricity of the eccentric weight. For this reason, it is possible to construct a vibration motor that can obtain a required vibration amount with light weight and low power consumption by using such a deviation and weights 1220, 1320, 1420, and 1520.

 [0159] In addition, Embodiment 12 1-15 [this deviation, weights 1220, 1320, 1420, 1520 [koyore ryoko, weights are held by each weight holding portion in the weight support over a half circumference] Therefore, as in the case of the eccentric weight 120-1120 according to Embodiment 1-11 11, 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. That force S is suppressed. Therefore, by using such eccentric weights 1220, 1320, 1420, 1520, a vibration motor with high long-term reliability can be configured.

 [Embodiment 16]

 FIG. 18 is a view for explaining the eccentric weight according to the sixteenth embodiment. FIG. 18 (a) is a view of the eccentric weight according to the embodiment 16 as viewed from the front, and FIG. 18 (b) is a cross-sectional view taken along the line A-A in FIG. 18 (a).

[0161] An eccentric weight 1620 according to the sixteenth embodiment has basically the same structure as the eccentric weight 920 according to the ninth embodiment. However, the eccentric weight 1620 according to Embodiment 16 is different from the eccentric weight 920 according to Embodiment 9 in the structure of the weight support 1630 as shown in FIG. The That is, in the eccentric weight 1620 according to the sixteenth embodiment, the thin wall region 1638 extends to both ends in the circumferential direction of the connecting portion 1636 of the weight support 1630.

 Therefore, according to the eccentric weight 1620 according to the sixteenth embodiment, the weight of the connecting portion 1636 can be further reduced. Therefore, the total weight of the eccentric weight 1620 can be further reduced, and the amount of eccentricity in the eccentric weight 1620 can be further increased. Therefore, by using such an eccentric weight 1620, it is possible to configure a vibration motor that can obtain a necessary vibration amount with lighter weight and less power consumption.

 Further, according to the eccentric weight 1620 according to the sixteenth embodiment, it is possible to easily produce the weight support body by the press drawing method, which also has an effect.

 [0163] The eccentric weight 1620 according to Embodiment 16 has the same configuration as that of the eccentric weight 920 according to Embodiment 9 in other points, and therefore the eccentric weight 920 according to Embodiment 9 is provided. It has the effect to do as it is.

 [Embodiment 17]

 FIG. 19 is a view for explaining the eccentric weight according to the seventeenth embodiment. FIG. 19 (a) is a view of the eccentric weight according to the seventeenth embodiment when the front force is also seen, and FIG. 19 (b) is a cross-sectional view taken along line AA in FIG. 19 (a).

 FIG. 20 is a view for explaining the vibration motor including the eccentric weight according to the seventeenth embodiment. FIG. 20 (a) is a view showing a vibration motor provided with the eccentric weight according to the seventeenth embodiment, and FIG. 20 (b) is a view showing another vibration motor provided with the eccentric weight according to the seventeenth embodiment.

 [0165] The eccentric weight 1720 according to the seventeenth embodiment has basically the same structure as the eccentric weight 1620 according to the sixteenth embodiment. However, the eccentric weight 1720 according to the seventeenth embodiment is different from the eccentric weight 1620 according to the sixteenth embodiment in the structure of the weight support 1730 as shown in FIG. That is, in the eccentric weight 1720 according to the seventeenth embodiment, the connecting portion 1736 that connects the weight holding portion 1734 and the motor shaft holding portion 1732 is a single connecting rod when viewed from the direction along the motor shaft 1712. It has a shape like this.

[0166] Therefore, according to the eccentric weight 1720 according to the seventeenth embodiment, the connecting portion 1736 has a shape that forms a single connecting rod when viewed from the direction along the motor shaft 1 712. Therefore, the eccentric weight 172 The total weight of 0 can be reduced and the amount of eccentricity in the eccentric weight 1720 can be further increased. For this reason, by using such an eccentric weight 1720, a vibration motor that is lighter and has a smaller amount of vibration required for power consumption than that of the eccentric weight 1620 according to Embodiment 16 can be configured. be able to.

[0167] The eccentric weight 1720 according to the seventeenth embodiment has the same configuration as the eccentric weight 1620 according to the sixteenth embodiment except for this, and therefore, the eccentric weight 162 according to the sixteenth embodiment 162.

It has the effect that 0 has.

In the eccentric weight 1720 according to the seventeenth embodiment, as shown in FIG. 20 (a), the motor shaft 1712 of the motor body 1710 is inserted into the motor shaft holding portion 1732 (see FIG. 19) of the eccentric weight 1720. The

,use.

 Further, as shown in FIG. 20 (b), the eccentric weight 1720 according to the seventeenth embodiment fixes the eccentric weight 1740 of the eccentric weight 1720 in the longitudinal direction of the weight 1740 and fixes the motor shaft of the motor main body 1710. 1712 may be inserted into the motor shaft holder 1732 of the eccentric weight 1720 for use. In this case, since the distance between the bearing 1714 of the motor main body 1710 and the motor shaft holding portion 1732 of the eccentric weight 17 20 becomes short, the eccentric weight 1720 rotates more stably, and thus there is a benefit that the eccentric characteristic is improved. can get.

 [0169] Although the eccentric weight, the manufacturing method thereof, the vibration motor, and the portable device of the present invention have been described based on the above embodiments, the present invention is not limited to the above embodiments. Without departing from the gist, the present invention can be carried out in various modes within the scope, and for example, the following modifications are possible.

 (1) In the eccentric weight 120-1720 of each of the above embodiments, the force using tungsten alloy as the weight is not limited to this. For example, a metal having a specific gravity higher than that of tungsten, osmium, osmium alloy, gold, gold alloy, iridium, iridium alloy, and other weight supports can be used.

[0171] (2) In the eccentric weight 120-1720 of each of the above embodiments, as a weight support, a member manufactured by a forging method, a member manufactured by a metal powder injection molding method, a press drawing The force using what was manufactured by the forming method The present invention is not limited to this. For example, those manufactured by forging, those manufactured by burring, What was manufactured by the forging method can also be used.

 [0172] (3) In the eccentric weight 120-1720 of each of the above embodiments, a sintered body made of a round bar is cut as a weight, and the cut body processed into the same cross-sectional shape as the weight is cut short. 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 that has the same cross-sectional shape as a weight (for example, a circle, an ellipse, a fan, etc.) is cut short. Can be used. In addition, when the cross-sectional shape of the weight is a circle, for example, a sintered body having a round bar force can be used as it is cut short.

 (4) The manufacturing method of the eccentric weight according to the first embodiment includes a step of clamping the weight support 130 in a state where the weight 140 is inserted into a weight holding hole 134 of the weight support 130. Although it is a manufacturing method, this invention is not limited to this. For example, the manufacturing method may include a step of press-fitting the weight 140 into the weight holding hole 134 in the weight support body 130 with a tightening margin, and the temperature of the weight support body 130 is higher than the temperature of the weight 140 Thus, the manufacturing method may include a step of inserting the weight 140 into the weight holding hole 134 in the weight support 130. Moreover, the manufacturing method including the process of joining the weight 140 and the weight support body 130 by brazing, adhesion | attachment, or welding may be sufficient. Further, the manufacturing method may include a step of inserting the material of the weight support 130 into a mold in a state where a part or all of the weight 140 is placed in a predetermined mold. Moreover, the manufacturing method which used the above-mentioned process together may be sufficient. For example, a manufacturing method including a step of bonding after crimping, a manufacturing method including a step of bonding after brazing, a manufacturing method including a step of spot welding after crimping, and brazing after spot welding. A manufacturing method including a process is also possible.

 [0174] (5) When the eccentric weight of the present invention is fixed to the motor body, the motor shaft in the motor body is joined to the motor shaft holding part in the eccentric weight of the present invention. For example, a joining method similar to the joining method of the weight and the weight support as shown in (4) above can be adopted.

[0175] (6) The joining position in the longitudinal direction of the weight holding part with respect to the weight in the eccentric weight of the present invention and the joining position in the longitudinal direction of the eccentric weight and the motor shaft in the vibration motor of the present invention It is not limited to the positional relationship shown in FIG. Thus, the embodiment The positional relationship shown in 17 can be applied in common to all the above-described embodiments.

(7) The vibration motor of the present invention can also be suitably used for a remote control of a game machine, a pachinko operation unit, an electric toothbrush, etc. suitably used for portable devices such as mobile phones and PDAs.

Claims

The scope of the claims

 [1] High specific gravity metal weight,

 A weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding the motor shaft, and a connecting portion for connecting the weight holding portion and the motor shaft holding portion, and constituting the weight An eccentric weight having a weight support body having a lower specific gravity and higher metal strength than a high specific gravity metal,

 The connecting portion has a thin region having a thickness smaller than a length along the motor shaft in the motor shaft holding portion, and a hole opening on both sides along the Z or the motor shaft. Eccentric weight.

 [2] A high specific gravity metal weight,

 A weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding the motor shaft, and a connecting portion for connecting the weight holding portion and the motor shaft holding portion, and constituting the weight An eccentric weight having a weight support body having a lower specific gravity and higher metal strength than a high specific gravity metal,

 The eccentric weight is characterized in that the connecting portion has a shape that forms a single connecting rod when viewed from a direction along the motor shaft.

[3] Weight with high specific gravity metal power,

 A weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding the motor shaft, and a connecting portion for connecting the weight holding portion and the motor shaft holding portion, and constituting the weight An eccentric weight comprising a weight support body having a structure in which a plurality of thin plate members made of metal having a specific gravity lower than that of the high specific gravity metal are laminated, wherein each connecting portion in the thin plate member holds the motor shaft An eccentric weight, comprising: a thin region having a thickness smaller than a length along the motor shaft in the portion; and a hole opening on both sides along the Z or the motor shaft.

[4] High specific gravity metal strength

A weight holding portion for holding the weight over a half circumference, a motor shaft holding portion for holding the motor shaft, and a connecting portion for connecting the weight holding portion and the motor shaft holding portion, and constituting the weight The specific gravity is lower than the high specific gravity metal. An eccentric weight comprising a weight support body having a structure in which thin plate members are stacked, wherein each connecting portion in the thin plate member is a single connecting rod as viewed from the direction along the motor shaft. An eccentric weight characterized by having a unique shape.

 [5] In the eccentric weight according to claim 1 or 3,

 The eccentric weight is characterized in that the thin region has a thickness of 50% or less of a length along the motor shaft in the motor shaft holding portion.

[6] In the eccentric weight according to claim 1, 3 or 5,

 The eccentric weight is characterized in that the thin region has a rib.

[7] In the eccentric weight according to any one of claims 1 to 6,

 An eccentric weight, wherein a thickness of the weight holding portion in an outer peripheral portion holding the weight from an outer peripheral side of the eccentric weight is 0.4 mm or less.

[8] In the eccentric weight according to any one of claims 1 to 7,

 An eccentric weight, wherein a thickness of the motor shaft holding portion is 0.4 mm or less.

[9] In the eccentric weight according to claim 1 or 3,

 The eccentric weight is characterized in that the thin region or the hole is formed by a cutting method.

 [10] In the eccentric weight according to any one of claims 1 to 8,

 The eccentric weight is characterized in that the weight support or the thin plate member is manufactured by a metal powder injection molding method V.

[11] The eccentric weight according to any one of claims 1 to 8,

 The eccentric weight is characterized in that the weight support or the thin plate member is manufactured by a press drawing method.

[12] The eccentric weight according to any one of claims 1 to 11,

 The eccentric weight is characterized in that the weight is held by the weight holding portion over the entire circumference.

 [13] The eccentric weight according to any one of claims 1 to 12,

An eccentric weight characterized in that the metal is stainless steel having a specific gravity lower than that of the high specific gravity metal constituting the weight.

[14] In the eccentric weight according to any one of claims 1 to 13,

 The eccentric weight is characterized in that the weight is tungsten, tungsten alloy, osmium, osmium alloy, gold, gold alloy, iridium or iridium alloy force.

[15] The eccentric weight according to any one of claims 1 to 14,

 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.

[16] A vibration motor comprising the motor main body and the eccentric weight according to any one of claims 1 to 15.

 17. A portable device comprising the vibration motor according to claim 16.