Vibration actuator

INDUSTRIAL APPLICABILITY The present invention is a small size used as a vibration source for notifying a user of an incoming call of a mobile wireless device such as a mobile phone, or a vibration source for transmitting the operation feeling of a touch panel or the presence of a game machine to a finger or a hand. It is related to the vibration actuator of.

Conventionally, Japanese Patent Application Laid-Open No. 10-117472 is available as a technique in such a field. The vibrating actuator described in FIG. 1 of this publication has a frame body to which a soft elastic body is fixed inside, and a columnar yoke made of a magnetic material is arranged in the frame body. This yoke also serves as a weight for generating vibration and is supported by a leaf spring inside the housing. This leaf spring is fixed to a plate-shaped first elastic body that closes the opening of the housing, and has a spiral-like shape with a raised center. Then, an annular coil is inserted into the annular groove formed on the end face of the yoke, and this coil is fixed to a plate-shaped second elastic body that closes the opening of the frame, and is formed on the wall surface of the groove. An annular magnet is fixed. In a vibrating actuator having such a configuration, when a current of a predetermined frequency is applied to the coil, the yoke that functions as a weight vibrates along the central axis, and the first and second elastic bodies resonate at a desired frequency. As a result, the desired vibration is generated in the frame.

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 10-117472</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2002-177882</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 2003-24871</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 2002-200460</text></patcit></p>

<p> However, in the conventional vibration actuator described above, the yoke vibrates in the direction of the central axis of the frame, so if the amplitude of the yoke is increased, the cylindrical frame becomes longer in the direction of the center axis, and the vibration actuator can be made thinner. It's hard to do. In addition, the yoke swings relatively freely inside the frame. Therefore, since the yoke is likely to collide violently with the frame due to a drop impact, it can be said that this vibration actuator has a structure with low impact resistance, and various measures are taken to mitigate the collision of the yoke with the frame. There is a problem that the structure becomes complicated.</p><p> An object of the present invention is to provide a vibration actuator that can be made thinner and has high drop impact resistance without complicating the structure.</p>

<p> The present invention relates to a vibrating actuator in which a magnet vibrates linearly in cooperation with a coil fixed to a housing and a magnet arranged facing the coil. A flat coil that extends in the direction of vibration, A flat magnet that extends in the direction of vibration, A shaft that extends in the direction of vibration and has both ends fixed to the housing, A spring receiving part that is provided in the housing and through which the shaft penetrates, Along with the shaft penetrating, the weight part connected to the magnet and arranged between the spring receiving part and the housing, It is characterized in that one end is supported by a weight portion and the other end is supported by a spring receiving portion.</p><p> Since this vibration actuator includes a flat coil extending in the vibration direction and a flat magnet extending in the vibration direction, the housing can be flattened, that is, thinned. Further, as compared with the vibration motor of the type in which the magnet rotates, the vibration actuator of the type in which the magnet vibrates linearly in the plane direction as in the present invention is more likely to obtain a large crisp vibration. Further, since the weight portion is supported by the shaft, the weight portion can be moved along the shaft at the time of a drop impact, so that the weight portion does not freely run wild in the housing, and thus the weight portion with respect to the housing. It does not require a complicated buffering means for alleviating the collision, and it is unlikely that the vibration actuator malfunctions caused by the large deformation of the weight portion due to the collision. Therefore, the drop impact resistance is improved without complicating the structure. In addition, since the spring is arranged between the spring receiving portion and the weight portion, space saving can be achieved without creating wasted space in the housing, and the vibration actuator can be made compact, that is, miniaturized. Can be done. In addition, it is highly efficient and can repeatedly obtain vibrations having a long life in a small space.</p><p> Further, the spring is a coil spring wound around the shaft, and the weight portion is composed of a first weight portion and a second weight portion arranged on both sides of the magnet in the vibration direction, and is the first. It is preferable that a coil spring is arranged between the weight portion and the spring receiving portion. Since the weights are arranged so as to sandwich the magnet in this way, well-balanced vibration can be generated. Furthermore, since a coil spring having a long natural length can be used, resonance due to the spring is likely to occur, and a large vibration can be obtained with a small driving force.</p><p> Further, it is preferable that another coil spring is arranged between the second weight portion and the spring receiving portion. The spring originally has hysteresis, but since two coil springs are placed between the first weight part and the second weight part with the spring receiving part in between, a well-balanced vibration is generated. Moreover, since each coil spring bears the load of vibration, the durability of the spring is enhanced and the life is extended.</p><p> Further, the magnet and the coil are arranged between the first yoke plate and the second yoke plate arranged in parallel with each other in the direction orthogonal to the vibration direction, and the first and second yoke plates are arranged. Both ends are fixed to the first and second weights, the magnet is fixed to the flat surface of the first yoke plate, and the coil faces the magnet and the second yoke plate apart from each other. It is preferable that it is arranged. By adopting the first and second yoke plates arranged in parallel in this way, it is possible to create an optimum magnetic circuit in the housing while maintaining the thinness of the vibrating actuator, and it is efficient and stable. The vibration can be obtained in the plane direction.</p>

<p> According to the present invention, it is possible to reduce the thickness and increase the drop impact resistance without complicating the structure.</p>

<figref num="1">It is a 1st Embodiment of the vibration actuator which concerns on this invention, and is the perspective view which shows the internal structure.</figref><figref num="2">It is a perspective view which shows the state which the lid part of the vibration actuator which concerns on this invention is removed.</figref><figref num="3">It is a top view which shows the state which exposed the internal structure by cutting the lid part of the vibration actuator which concerns on this invention.</figref><figref num="4">It is sectional drawing along the IV-IV line of FIG.</figref><figref num="5">It is sectional drawing along the VV line of FIG.</figref><figref num="6">It is a top view which shows the 2nd Embodiment of the vibration actuator which concerns on this invention.</figref><figref num="7">It is sectional drawing which shows the 3rd Embodiment of the vibration actuator which concerns on this invention.</figref>

Hereinafter, preferred embodiments of the vibration actuator according to the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 to 5, the vibration actuator 1 has a flat housing 4 including a base plate 2 and a lid 3. An annular flat coil 6 fixed to the base plate 2 and a plate-shaped flat magnet 7 arranged facing the coil 6 are housed in the housing 4. The magnet 7 is formed by two magnet portions 7a and 7b having an N pole on one flat side and an S pole on the other flat side. In this magnet 7, the north pole of one magnet portion 7a and the south pole of the other magnet portion 7b are opposed to each other on a plane, and the side surface of the magnet portion 7a and the side surface of the magnet portion 7b are attached by an adhesive. It is composed by matching. The magnet 7 may be formed by magnetizing a single magnetic plate.

Further, the coil 6 is connected to the terminal electrode 5 provided on the base plate 2 via the wiring 5a. Then, when a rectangular square wave or sine wave current is applied to the coil 6 from the outside via the terminal electrode 5, the magnet 7 vibrates linearly in the plane direction.

The magnet 7 is fixed to the flat surface portion 8a forming the back surface of the first yoke plate 8 made of a magnetic material by an adhesive, and the ends of the first yoke plate 8 are the first weight portion 11 and the second. It is attached to the first and second weight portions 11 and 12 so as to bridge the weight portion 12. The first and second weight portions 11 and 12 extend in a direction orthogonal to the vibration direction with the same shape and weight, and the shaft 13 penetrates both ends of the respective weight portions 11 and 12, respectively. Both ends of the shaft 13 of the above are fixed to the upright portions 2a provided at the ends of the base plate 2 of the housing 4. The shaft 13 extends in the vibration direction to serve as a guide and a support for the first and second weight portions 11 and 12. The first and second weight portions 11 and 12 may be provided with a resin portion in order to improve the slidability with the shaft 13, and the shaft 13 may be passed through the resin portion.

A spring receiving portion 14 erected on the base plate 2 of the housing 4 is provided between the first weight portion 11 and the second weight portion 12, and the shaft 13 penetrates the spring receiving portion 14. ing. With such a configuration, the first and second weight portions 11 and 12, respectively, are arranged between the spring receiving portion 14 and the lid portion 3 of the housing 4 in the vibration direction.

A first coil spring 16 is arranged between the first weight portion 11 and the spring receiving portion 14, and the shaft 13 penetrates the first coil spring 16. A second coil spring 17 is arranged between the second weight portion 12 and the spring receiving portion 14, and the shaft 13 penetrates the second coil spring 17. The first coil spring 16 and the second coil spring 17 have the same spring constant and the same length. Both ends of the first and second coil springs 16 and 17 are supported without being fixed to the first weight portion 11, the second weight portion 12, and the spring receiving portion 14.

The magnet 7 and the coil 6 are arranged between the flat plate portion 18A of the first yoke plate 8 and the second yoke plate 18 arranged in parallel with each other in a direction orthogonal to the vibration direction. The first yoke plate 8 made of a magnetic material is fixed to the upper surfaces of the first and second weight portions 11 and 12 via an adhesive, and the second yoke plate 18 made of a magnetic material is the first and first. It is fixed by caulking to the weights 11 and 12 of 2. Both ends of the second yoke plate 18 are bent in a U shape, and the bent pieces 18a and 18b bent at right angles at both ends of the flat plate portion 18A of the second yoke plate 18 have the first and second Through holes 18c and 18d for inserting the convex portions 11a and 12a protruding from the weight portions 11 and 12 are formed, and by crushing the heads of the convex portions 11a and 12a, the second yoke plate 18 and the first and the first The second weights 11 and 12 are integrated by caulking.

A flat coil 6 is arranged between the magnet 7 and the flat plate portion 18A of the second yoke plate 18, and the coil 6 is separated from the flat plate portion 18A of the magnet 7 and the second yoke plate 18. They are arranged so as to face each other. By adopting the first and second yoke plates 8 and 18 arranged in parallel in this way, it is possible to create an optimum magnetic circuit in the housing 4 while maintaining the thinness of the vibrating actuator 1. It is possible to obtain efficient and stable vibration in the plane direction.

As described above, the vibration actuator 1 described above includes the flat coil 6 extending in the vibration direction and the flat magnet 7 extending in the vibration direction, so that the housing 4 is flattened, that is, thinned. Can be done. Further, as compared with the vibration motor of the type in which the magnet rotates, the vibration actuator 1 of the type in which the magnet 7 vibrates linearly in the plane direction as in the present invention is more likely to obtain a large crisp vibration.

Further, since the weights 11 and 12 are supported by the shaft 13, the weights 11 and 12 can be moved along the shaft 13 at the time of a drop impact, whereby the weights 11 and 12 are inside the housing 4. It does not require complicated buffering means to mitigate the collision of the weights 11 and 12 with the housing 4, and it is caused by the large deformation of the weights 11 and 12 due to the collision. It is unlikely that the vibration actuator 1 will malfunction. Therefore, the drop impact resistance is improved without complicating the structure.

In addition, since the coil springs 16 and 17 are arranged between the spring receiving portion 14 and the weight portions 11 and 12, space saving is achieved without creating wasted space in the housing 4, and the vibration actuator is vibrated. It is possible to achieve 1 compactness, that is, miniaturization. The same effect can be obtained by using another spring, for example, a leaf spring instead of the coil spring.

Further, in such an arrangement of the coil springs 16 and 17, since a coil spring having a long natural length can be used, resonance due to the spring is likely to occur, and a large vibration can be obtained with a small driving force.

Further, since the weight portions 11 and 12 are arranged so as to sandwich the magnet 7 in the vibration direction, well-balanced vibration can be generated.

The spring originally has hysteresis, but since the two coil springs 16 and 17 are arranged between the first weight portion 11 and the second weight portion 12 with the spring receiving portion 14 interposed therebetween, the balance is balanced. Since extremely good vibration is generated and each coil spring 16 and 17 bears the load of vibration, the durability of the spring is enhanced and the life is extended.

Needless to say, the present invention is not limited to the above-described embodiments.

For example, as shown in FIG. 6, in another vibration actuator 20, the coil spring 21 is arranged only between the first weight portion 11 and the spring receiving portion 14, and both ends of the coil spring 21 are the first weight portions. By fixing to 11 and the spring receiving portion 14, the vibrating actuator 20 can be vibrated without separating the first weight portion 11 from the coil spring 21, and the weight portions 11 and 12 can be moved at the time of a drop impact when no power is applied. There is little rampage. The vibrating actuator 20 has the same other configurations as the vibrating actuator 1.

As shown in FIG. 7, the other vibrating actuator 30 does not employ the second yoke plate 18 on the coil 6 side. Both ends of the first yoke plate 31 to which the magnet 7 is fixed are bent in a U shape, and the bent pieces 31a and 31b bent at right angles at both ends of the flat plate portion 31A of the second yoke plate 31 are Through holes are formed for inserting the convex portions protruding from the first and second weight portions 11 and 12, and the heads of the convex portions are crushed and crimped to form the first yoke plate 31 and the first yoke plate 31 and the first. The 1st and 2nd weights 11 and 12 are integrated. The vibrating actuator 30 has the same other configurations as the vibrating actuator 1.

1,20,30 ... Vibration actuator, 4 ... Housing, 6 ... Coil, 7 ... Magnet, 8 ... 1st yoke plate, 8a ... Flat part, 11.. .1st weight part, 12 ... 2nd weight part, 13 ... shaft, 14 ... spring receiving part, 16 ... 1st coil spring, 17 ... 2nd coil spring , 18 ... Second yoke plate.