Vibration generator with elastic member with extending regions and bending metal plate to support the vibrator

A vibration generator includes a housing; a vibrator; an elastic member that connects the housing and the vibrator; and a driver that causes the vibrator to vibrate. The elastic member includes a housing connection portion that is connected to the housing, a vibrator support portion that supports the vibrator, and a spring portion that connects the housing connection portion and the vibrator support portion. The housing connection portion and the vibrator support portion are in the same plane. The spring portion is formed so as to be approximately perpendicular to the housing connection portion and the vibrator support portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority to Japanese Patent Application No. 2019-090497, filed on May 13, 2019, and Japanese Patent Application No. 2019-215233, filed on Nov. 28, 2019, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosures herein generally relate to a vibration generator.

2. Description of the Related Art

Some mobile electronic equipment, such as mobile phones and game consoles, are equipped with vibration generators that generate vibrations for notifying users of incoming calls or providing users with tactile feel in accordance with the game situations. As such vibration generators, a vibration generator that includes a magnet and causes the magnet to vibrate is disclosed (Patent Document 1, for example). In the vibration generator disclosed in Patent Document 1, the magnet is disposed on a plate spring that is formed by bending a metal plate in different directions.

In the above-described vibration generator, because the plate spring is formed by bending a metal plate a plurality of times in different directions, a plurality of molds and a plurality of pressing process are required, thus making it difficult to manufacture the vibration generator.

Patent Documents

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide a vibration generator that can be readily manufactured.

According to one embodiment of the present invention, a vibration generator includes a housing; a vibrator; an elastic member that connects the housing and the vibrator; and a driver that causes the vibrator to vibrate. The elastic member includes a housing connection portion that is connected to the housing, a vibrator support portion that supports the vibrator, and a spring portion that connects the housing connection portion and the vibrator support portion. The housing connection portion and the vibrator support portion are in the same plane. The spring portion is formed so as to be approximately perpendicular to the housing connection portion and the vibrator support portion.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to one embodiment of the present invention, it is possible to provide a vibration generator that can be readily manufactured without requiring a plurality of molds and a plurality of pressing processes.

In the following, embodiments will be described. The same members are denoted by the same reference numerals, and a description thereof will not be repeated. Further, in the present application, an X1-X2 direction, a Y1-Y2 direction, and a Z1-Z2 direction are mutually perpendicular directions. Further, a plane including the X1-X2 direction and the Y1-Y2 direction is referred to as a XY-plane, a plane including the Y1-Y2 direction and the Z1-Z2 direction is referred to as a YZ-plane, and a plane including the Z1-Z2 direction and the X1-X2 direction is referred to as a ZX-plane.

First Embodiment

A vibration generator according to a first embodiment will be described with reference toFIG.1andFIG.2.FIG.1is a perspective view of the vibration generator according to the first embodiment.FIG.2is an exploded perspective view of the vibration generator according to the first embodiment. The vibration generator according to the first embodiment includes a cover10, an upper yoke20, a coil30, a bracket40, a magnet50, a lower yoke60, an elastic member70, and a housing80. Note that, in the present embodiment, the cover10, the bracket40, the elastic member70, and the housing80are formed of non-magnetic stainless steel. The upper yoke20and the lower yoke60are formed of a magnetic material including Fe and the like.

As illustrated inFIG.1, the vibration generator according to the present embodiment has an approximately rectangular parallelepiped shape whose largest surface is parallel to the XY-plane. The vibration generator is formed such that the length in the X1-X2 direction (longitudinal direction) of the largest surface is 15 mm, the width in the Y1-Y2 direction (lateral direction) is 10 mm, and the height in the Z1-Z2 direction (height direction) is 3 mm.

A casing of the vibration generator according to the present embodiment is configured by the housing80and the cover10. As illustrated inFIG.3andFIG.4, the housing80has an approximately rectangular frame shape, and has an opening81through the Z1-Z2 direction. Further, a bottom plate portion82parallel to the XY-plane is formed on the Y2 (Z2) side of the opening81. Further, bracket support portions83are provided at the middle of the Y1 side and Y2 side of the housing80.

The housing80accommodates the elastic member70, the lower yoke60, the magnet50, the bracket40, the coil30, and the upper yoke20, and the cover10is placed from the Z1 side (the upper side). Further, in the present application, the casing configured by the housing80or by the cover10and the housing80may be referred to as a case.

As illustrated inFIG.5, the coil30is wound such that the coil30extends in the Y1-Y2 direction, and includes terminals31and32between which a current flows. The coil30is disposed on a surface40aon the Z1 side of the bracket40, and is fixed to the bracket40. Further, housing attachment portions41for connection to the housing80are formed on the Y1 side and Y2 side of the bracket40, so as to extend in the Z2 direction. Note that the bracket40is formed by punching and bending a metal plate such as non-Magnetic stainless steel.

As illustrated inFIG.6, the upper yoke20has a rectangular flat plate shape whose longitudinal direction is the X1-X2 direction and the lateral direction is the Y1-Y2 direction. The lower yoke60has a recessed portion61whose longitudinal direction is the X1-X2 direction and that is recessed in the Z2 direction. Side surfaces61bextending from a bottom surface61ain the Z1 direction are formed on the X1 side and on the X2 side of the recessed portion61of the lower yoke60. Further, connecting portions62extend outwardly relative to the side surfaces61bin the X1 direction and the X2 direction. On the Z1 side of the magnet50, the X1 side of the magnet50is the S-pole and the X2 side is the N-pole. On the Z2 side of the magnet50, the X1 side of the magnet50is the N-pole and the X2 side is the S-pole.

When a vibrator of the vibration generator according to the present embodiment is assembled, the magnet50is attached to the bottom surface61aof the recessed portion61of the lower yoke60. Further, the connecting portions62of the lower yoke60are joined to the upper yoke20. In the present embodiment, the lower yoke60and the upper yoke20, located in the surroundings of the magnet50, are separate members, thus allowing the vibrator to be readily assembled.

As illustrated inFIG.7andFIG.8, the surface on the Z2 side of the magnet50is joined to the bottom surface61aof the recessed portion61of the lower yoke60, and the surfaces on the Z1 side of the connecting portions62, which are located on the X1 side and the X2 side of the lower yoke60, are joined to connecting portions21of the upper yoke20. Further, the coil30, which is fixed to the bracket40, is provided on the Z1 side relative to the magnet50, within a region defined by the recessed portion61between the lower yoke60and the upper yoke20.

The bracket40is attached to the housing80by inserting the housing attachment portions41of the bracket40into openings of the bracket support portions83of the housing80. Accordingly, the vibrator is formed by the upper yoke20, the magnet50, and the lower yoke60. However, the vibrator is not connected to either the bracket40or the coil30.

As illustrated inFIG.9, the elastic member70includes a housing connection portion71, a vibrator support portion72, and spring portions73. The housing connection portion71is fixed to the housing80by connecting the surface on the Z2 side of the housing connection portion71to the surface on the Z1 side of the bottom plate portion82of the housing80. Further, the Z2 side of the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, is joined and fixed to the Z1 side of the vibrator support portion72. The spring portions73are provided between the housing connection portion71and the vibrator support portion72.

The elastic member70is formed as follows. First, a metal plate such as non-magnetic stainless steel having a thickness of 0.1 mm is punched to obtain a punched metal plate as illustrated inFIG.10. Next, the elastic member70as illustrated inFIG.9is formed by bending the punched metal plate. The spring portions73are formed by bending both ends on the X1 side and the X2 side of the punched metal plate illustrated inFIG.10approximately perpendicularly with respect to bend lines70a(the bend lines70aare illustrated inFIG.9), which are parallel to the Y1-Y2 direction. In the elastic member70, the housing connection portion71and the vibrator support portion72are in the same plane.

The metal plate forming the elastic member70has a groove74, which is formed by punching the metal plate. The housing connection portion71and the vibrator support portion72are separated by a first groove74aof the groove74. The first groove74aof the groove74extends in the X1-X2 direction, and is perpendicular to the Y1-Y2 direction in which the bend lines70aextend. Accordingly, the housing connection portion71is formed on the Y2 side of the first groove74aof the groove74, and the vibrator support portion72is formed on the Y1 side of the first groove74aof the groove74.

Further, the spring portions73are formed approximately in parallel to the YZ-plane. The groove74includes a second groove74bthat extends in the Y1-Y2 direction, and the second groove74bis formed in each of the spring portions73, thus allowing the spring portions73to have desired elasticity. The spring portions73each include a first region73aconnected to the housing connection portion71and extending from the housing connection portion71in the Z1 direction; a second region73bextending from the first region73ain the Y1 direction; a third region73cextending from the second region73bin the Z2 direction; and a fourth region73dconnecting the third region73cto the vibrator support portion72and extending in the Y1-Y2 direction. The second region73band the fourth region73dare separated by the second groove74bthat extends in the Y1-Y2 direction, and the second region73bextends in the Y1-Y2 direction and in particular, functions as a spring. Accordingly, the second region73bof each of the spring portions73extends in a direction parallel to the bend lines70a.

When an elastic member such as a spring is formed by bending a metal plate, it would be difficult to bend the metal plate at an angle of approximately 180° in terms of manufacturing. Further, due to the decreased strength of the bent portion, the metal plate would be readily damaged when vibrated. In view of the above, in the present embodiment, the elastic member70is formed by bending a metal plate at approximately 90°, in order to enable easy manufacturing and to prevent a decrease in strength. Accordingly, the vibration generator can be readily manufactured and reliability can also be improved.

Further, the vibrator is joined to the vibrator support portion72. The vibrator support portion72is provided with bent portions75that are formed by causing portions on the X1 side and the X2 side of the vibrator support portion72to be bent approximately perpendicularly. The bent portions75are situated on the X1 side and the X2 side of the vibrator. The bent portions75may be used as marks for alignment when the vibrator is attached to the vibrator support portion72, or may be used as support portions for supporting the X1 side and the X2 side of the vibrator.

Next, the generation of a vibration by the vibration generator according to the present embodiment will be described.FIG.11depicts the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, and also the coil30and the bracket40provided within a space between the lower yoke60and the upper yoke20, of the vibration generator according to the present embodiment. Dashed arrows inFIG.11indicate magnetic lines of force generated by the magnetic field of the magnet50.FIG.12is a front view of the vibration generator according to the present embodiment.

Specifically, on the X1 side of the magnet50, a magnetic line of force is directed from the N-pole on the Z2 side into the S-pole on the X1 side of the magnet50, through the inside of the lower yoke60, the inside of the upper yoke20, and a space between the upper yoke20and the S-pole on the X1 side of the magnet50. Further, on the X2 side of the magnet50, a magnetic line of force is directed from the N-pole on the Z1 side into the S-pole on the X2 side of the magnet50, through a space between the N-pole on the X2 side of the magnet50and the upper yoke20, the inside of the upper yoke20, and the inside of the lower yoke60. Further, a magnetic line of force directed from the N-pole into the S-pole is present on the Z1 side of the magnet50, and a magnetic line of force directed from the N-pole into the S-pole is present on the Z2 side of the magnet50.

Accordingly, the magnetic lines of force concentrate in the space between the upper yoke20and the lower yoke60, and the magnetic field is thus strong. The coil30is provided in this space. In the present embodiment, an alternating current flowing between the terminal31and the terminal32allows the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, to vibrate in the X1-X2 direction.

For example, when a current is applied such that the terminal31of the coil30becomes positive and the terminal32becomes negative, the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, moves in the X2 direction. Further, when a current is applied such that the terminal31of the coil30becomes negative and the terminal32becomes positive, the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, moves in the X1 direction. Therefore, the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, can vibrate in the X1-X2 direction by applying a current such that the terminal31and the terminal32of the coil30become alternately positive and negative. Note that the coil30and the bracket40do not vibrate because the bracket40, to which the coil30is fixed, is separated from the vibrator.

As the weight of the vibrator increases, the resulting generated vibration is stronger. For this reason, the weight of the vibrator is increased by increasing the length in the X1-X2 direction of each of the connecting portions21of the upper yoke20, to which the connecting portions62of the lower yoke60are connected. In the present application, the connecting portions62of the lower yoke60and the connecting portions21of the upper yoke20, to which the connecting portions62are connected, may be collectively referred to as “extended regions63”. In the present embodiment, the length L in the X1-X2 direction of each of the extended regions63is approximately 1.3 mm, and the weight of the vibrator is increased by the weight of the extended regions63formed on both sides. The thickness of the upper yoke20is 0.3 mm, and the thickness of the lower yoke60is 0.5 mm. Thus, the lower yoke60is thicker than the upper yoke20.

In the present embodiment, the weight of the vibrator, formed by the upper yoke20, the magnet50, and the lower yoke60, is 1.03 g. Further, when the vibrator is vibrated at the natural frequency of 99 Hz, a stroke length of ±1.2 mm, that is, the total stroke length of 2.4 mm in the X1-X2 direction can be obtained. As a result, a strong vibration can be obtained.FIG.13depicts a state in which the vibrator is displaced after the vibration generator is vibrated. As illustrated inFIG.13, the second region73bof each of the spring portions73of the elastic member70is largely deformed, indicating that the second region73bserves as a main elastic region and functions as a spring.

The extended regions63formed by the upper yoke20and the lower yoke60preferably extend in the vibration direction, outwardly relative to the recessed portion61of the lower yoke60. In the present embodiment, the X1-X2 direction is the vibration direction. In the Y1-Y2 direction perpendicular to the vibration direction, the bracket40supporting the coil30is connected to the housing80. Thus, it would be difficult to form extended regions with sufficient mass in the Y1-Y2 direction. Further, if extended regions are formed in the Z1-Z2 direction, the height of the vibration generator would be increased, thus failing to satisfy downsizing requirements. Accordingly, the extended regions63are formed in the X1-X2 direction, which is the vibration direction.

As illustrated inFIG.14, in the vibration generator according to the present embodiment, the housing80has the opening81in a region corresponding to the vibrator support portion72of the elastic member70. That is, on the Z2 side of the housing80, the opening81is formed in the region corresponding to the vibrator support portion72of the elastic member70. Accordingly, because the housing80has the opening81in the region corresponding to the vibrator support portion72of the elastic member70, the housing80does not contact the vibrator support portion72of the elastic member70, and thus does not hinder the vibration of the vibrator. Specifically, in the present embodiment, the housing connection portion71of the elastic member70and the vibrator support portion72are in the same plane. Therefore, if the housing80has a bottom plate portion in the region where the vibrator support portion72is situated, the bottom plate portion of the housing80would contact the vibrator support portion72, and friction would be generated when the vibrator is vibrated, thus causing the vibration of the vibrator to be hindered. In the present embodiment, the housing80has the opening81in the region corresponding to the vibrator support portion72of the elastic member70. Accordingly, the housing80does not contact the vibrator support portion72of the elastic member70, and thus, does not affect the vibration of the vibrator.

Further, it may be contemplated that an elastic member may be formed such that a vibrator support portion is situated on the Z2 side relative to a housing connection portion, thereby providing a level difference between the housing connection portion and the vibrator support portion. In this case, even if the housing has a bottom plate portion in a region in which the vibrator support portion is situated, a gap is formed between the vibrator support portion and the bottom plate portion of the housing. Thus, the vibration of the vibrator would not be hindered.

However, in the above case, because bend lines for forming the housing connection portion are out of line with bend lines for forming the vibrator support portion, manufacturing processes and time would be increased, thus resulting in an increase in costs. Further, in the above case, the height in the Z1-Z2 direction of the vibration generator would be increased by the height of the gap between the vibrator support portion and the bottom plate of the housing. Therefore, the size of the vibration generator would be increased.

Conversely, in the vibration generator according to the present embodiment, the bend lines for forming the housing connection portion71are in line with the bend lines for forming the vibrator support portion72. Therefore, the vibration generator can be readily manufactured at low costs. Further, the height of the vibration generator can be decreased by the height of the above-described gap. Thus, the size of the vibration generator can be reduced.

Next, a variation of the present embodiment will be described with reference toFIG.15. As illustrated inFIG.15, in a case where there is no need to provide either marks for alignment when the vibrator is attached to the vibrator support portion72or support portions for supporting the X1 side and the X2 side of the vibrator, the elastic member70is not required to include bent portions75. If the elastic member70does not include bent portions75, a bending process for forming bent portions75becomes unnecessary, thus allowing the elastic member70to be more readily manufactured at lower costs. Accordingly, the cost of the vibration generator can be further reduced.

Second Embodiment

Next, a vibration generator according to a second embodiment will be described with reference toFIG.16throughFIG.19.FIG.16is a perspective view of the vibration generator, viewed from the bottom side, according to the second embodiment.FIG.17is a perspective view of a housing180of the vibration generator according to the second embodiment.FIG.18is a perspective view of the housing180to which the elastic member70is attached.FIG.19is a perspective, cross-sectional view of the vibration generator according to the second embodiment.

The vibration generator according to the present embodiment differs from that of the first embodiment, in that the housing180does not have a large opening through the Z1-Z2 direction. Specifically, the housing180has an approximately rectangular parallelepiped shape, and includes a bottom surface181and bottom surface support portions182, which are provided on the Z2 side and parallel to the XY-plane, and also includes four side surfaces parallel to the YZ-plane or the ZX-plane. In the present application, a casing formed by the housing180or by the cover10and the housing180may be referred to as a case.

The bottom surface support portions182are tongues that are bent from a side surface183so as to be parallel to the XY-plane. The side surface183, of the side surfaces of the housing180, is situated on the Y2 side and extends in the Z1 direction (toward the upper side) from the bottom surface181. Accordingly, the bottom surface181and the bottom surface support portions182are in parallel.

Similar to the bottom plate portion82according to the first embodiment, the housing180includes the bottom surface support portions182on the Y2 side such that the housing connection portion71of the elastic member70is connected and fixed to the bottom surface support portions182.

Accordingly, the surface on the Z2 side of the housing connection portion71of the elastic member70is connected and fixed to the surfaces on the Z1 side of the bottom surface support portions182of the housing180.

The bottom surface support portions182are provided on the Z1 side by 1 mm to 2 mm relative to the bottom surface181. The bottom surface support portions182are connected to the housing connection portion71of the elastic member70so as to support the elastic member70. The bottom surface181covers the approximately entire vibrator support portion72of the elastic member70. By providing the housing180with the bottom surface181that covers the entire vibrator support portion72of the elastic member70, it is possible to prevent the vibrator support portion72of the elastic member70from contacting other external members. Further, the strength of the housing180can be increased by providing the housing180with the bottom surface181.

As described above, in the present embodiment, the bottom surface support portions182of the housing180is provided below the vibrator support portion72of the elastic member70, and the bottom surface181is provided below the bottom surface support portions182. That is, on the Z2 side of the housing180, the bottom surface181is provided below the vibrator support portion72of the elastic member70, and the bottom surface181is provided below the bottom surface support portions182.

Accordingly, a gap is formed between the bottom surface181of the housing180and the vibrator support portion72of the elastic member70. Therefore, when the vibrator support portion72of the elastic member70is vibrated, the bottom surface181of the housing180does not contact and rub against the vibrator support portion72, and thus, the housing180does not hinder the vibration of the vibrator support portion72.

In the present embodiment, the housing connection portion71of the elastic member70is attached to the upper surfaces of the bottom surface support portions182of the housing180. However, the housing connection portion71of the elastic member70may be attached to the lower surfaces of the bottom surface support portions182of the housing180, as long as a gap is formed between the vibrator support portion72of the elastic member70and the bottom surface181of the housing180.

Although the embodiments have been specifically described above, the present invention is not limited to the specific embodiments and various modifications and variations may be made without departing from the scope of the present invention.