JP3835740B2 - Axial driven vibrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of a vibrating body used in a portable device or the like that makes a mobile phone sense an incoming call without sound.
[Prior art]
Conventionally, in vehicles such as public places, hospitals, trains and buses, use of portable devices is often restricted. In particular, even when the use of a portable device is permitted, a method of causing a mobile phone to detect an incoming call in a so-called manner mode (silence / body vibration) is performed. Various products have been widely used in mobile devices reflecting recent technological advances, such as mobile phones, PDAs, wearable computing devices, and the like. For these, a vibration motor that senses a sensory vibration without sound, a multi-function device (having both a speaker and a vibrating body function) having a similar function, and the like are used. Below, what is considered to be a typical example of a conventional vibration motor will be described.
[0002]
Examples of the prior art will be described with reference to Japanese Unexamined Patent Application Publication No. Hei 3-83681 (hereinafter referred to as Document A), Japanese Patent Application Laid-Open No. 7-107699 (Document B), and Japanese Patent Publication No. 8-10972 (Document C). Document A uses a shaft length type DC motor having a brush and a commutator, and relates to an eccentric weight having a fan-shaped cross section to be mounted on a rotating shaft of a vibration motor. The eccentric weight is made of a powder sintered alloy of a metal containing tungsten or lead without using a bulk material of tungsten that has a high specific gravity but is difficult to process, making it easy to fit the eccentric weight to the rotating shaft. Try to increase the output.
[0003]
Document B is a vibration motor using a shaft length type DC motor having a brush and a commutator as outlined in FIG. 5, and relates to the disclosure of a configuration of an eccentric weight and a fixing method to a rotating shaft. In FIG. 5, a rotating shaft 136 supported by a bearing 133 of a DC motor 131 is provided with a groove 135 smaller than the outer diameter of the rotating shaft 136, and is made of an eccentric powder made of a powder sintered alloy such as tungsten formed of a high specific gravity material. The weight 134 is crimped to the groove 135 of the rotating shaft 136 by the crimping portion 140. Therefore, both ends of the eccentric weight 134 in the axial direction are not raised, and the eccentric weight 134 is securely fixed to the rotating shaft 136, so that the output can be increased despite the small size. Further, it is described that the porous eccentric weight 134 is impregnated with oil and has a rust prevention effect without surface treatment by plating.
[0004]
Document C relates to a flat DC motor having a brush and a commutator. At least three coils having an opening angle of 60 to 80 ° are arranged in a fan shape so as not to overlap with each other, and an eccentric weight is formed by a rotor configuration. Form.
[0005]
[Problems to be solved by the invention]
Documents A, B, and C are premised on the rotation of a DC motor, and there are the following difficulties although there are differences between the long axis type and the flat type. (1) Since a brush and a commutator are used, the cost is high, and there is a problem in maintaining the life and quality due to damage caused by a micro arc during rectification. (2) It takes time to rise up to 7000-8000 rpm, and is not suitable for a device that generates vibration in accordance with music.
An object of the present invention is to propose a compact and high-performance axially driven vibrator that eliminates the above-mentioned drawbacks and enriches the functions of portable devices that are diversified with a simple configuration.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the vibrator of the present invention, a cylindrical drive coil is fixed to one end of a cylindrical frame, and magnetically engaged with the drive coil via a gap. Consists of a cup-shaped yoke made of a material, a driver having a cylindrical permanent magnet enclosed in the cup-shaped yoke and fixed at one end and having a weight mounted thereon, and a pair of coil springs elastically supporting the driver In the axially driven vibrating body, a plurality of rows of guide convex portions parallel to the axial direction are provided on the inner peripheral surface of the frame, and guide grooves that mechanically slide-engage with the guide convex portions are provided in the driver element. A plurality of rows are provided in parallel in the axial direction on the outer peripheral surface of the frame. A coil spring vibrates the driver in the axial direction. It is characterized in that arranged so as.
[0007]
In order to achieve the above object, according to a second aspect of the vibrating body of the present invention, a columnar pole piece made of a magnetic material is provided at the other end of the columnar magnet included in the cup-shaped yoke of the driver. It is characterized by being fixed .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an axially driven vibrator according to the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view of a configuration of an axially driven vibrator (hereinafter abbreviated as vibrator) according to the present invention. FIG. 2 is a sectional view taken along line XX of FIG. FIG. 3 is a cross-sectional view of another embodiment of the present invention. FIG. 4 is a diagram illustrating the configuration of a driver element according to another embodiment of the present invention. 1 and 2, the vibrating body 10 of the present invention includes a cylindrical frame 11 made of synthetic resin, a drive coil 12, and a drive element 20. One end of the frame 11 in the axial direction is formed by winding a magnet wire around a cylindrical coil bobbin 13 whose surface is electrically insulated by anodizing a metal material such as aluminum having good thermal conductivity. The drive coil 12 having 36 is fixed in a cantilever manner. The driver 20 has a cylindrical permanent magnet 22 axially magnetized with a single magnetic pole fixed in a cantilever shape at the center of a cup-shaped yoke 21 made of a magnetic material. For example, a weight 23 formed by resin molding of a large amount of tungsten powder, for example, is fixed with an adhesive or the like. In order to enable the driver 20 to be smoothly driven in the axial direction, a plurality of rows (two rows in the embodiment) of guide protrusions (14a, 14b, 14c), (15a, 15b, 15c) are arranged. The guide protrusions (14a, 15a), (14b, 15b), and (14c, 15c) are formed in the same row in parallel with the axial direction. Further, the drive coil 12 and the driver 20 are magnetically engaged through circumferential gaps 26 and 27 parallel to the axial direction. Further, the driver 20 is supported by coil springs 24 and 25 provided on both side ends of the frame 11. The primary resonance frequency of the driver element 20 is determined by the mass of the driver element 20 and the stiffness of the coil springs 24 and 25, and is set to 100 to 160 Hz, which is considered to be highly sensitive to the wearer. The driver 20 is normally stopped at an equilibrium point by a pair of coil springs 24 and 25.
[0015]
In FIG. 3, the driving element 30 is provided with guide grooves 31a, 31b, 31c parallel to the axial direction, and the guide protrusions 41a, 41b, 41c of the frame 40 correspond to the guide grooves 31a, 31b, 31c, respectively. Slidably engage. As a result, when the driver 30 reciprocates in the axial direction, pitching, rolling and yawing are not generated, and efficient reciprocating vibration in the axial direction is generated. In addition, when the weight 23 is mounted, the vibrational shaking force can be further increased.
[0016]
FIG. 4 shows an embodiment in which a columnar pole piece 28 made of a magnetic material is disposed at the tip of the columnar permanent magnet 22 that is magnetically engaged with the drive coil 12. According to the embodiment of the present invention, since the magnetic flux distribution from the pole piece 28 spreads in the diameter direction of the drive coil 12, the number of magnetic flux linkages of the drive coil 12 can be greatly increased, and the conversion efficiency to vibration energy is improved. Can be made.
[0017]
In the description of the vibrator of the present invention so far, the cross-sectional shape in the axial direction of the frame 11, the drive coil 12, the drive elements 20, 30, etc. is a cylindrical shape that is easy to manufacture, but is not limited to this. Any shape may be used as long as it does not hinder the movement of the drive elements 20 and 30 in the axial direction in consideration of the mounting arrangement of the ellipse, square, etc. on the portable device.
[0018]
The driving elements 20 and 30 are driven by an AC signal such as a sine wave or a square wave having a fundamental frequency substantially the same as the primary resonance frequency of the driving elements 20 and 30 between the terminals 35 and 36 of the driving coil 12. It is energized and driven. Of course, it can be driven by unipolar driving by a sine wave or square wave.
[0019]
Although a pair of coil springs 24 and 25 are used for the driver elements 20 and 30, one coil spring may be used. In this case, the drive elements 20 and 30 are set so as to be pressed in one direction, and the drive is driven so as to overcome the static force of the coil spring. According to this method, since the driving elements 20 and 30 are held in one direction by vibrations, impacts, etc. of the portable device, the vibrating body is protected.
[0020]
Further, the configuration of the driver elements 20 and 30 of the embodiment of the present invention has been described with the cup-shaped yoke 21 and the columnar permanent magnet 22, but they are replaced with each other and are cup-shaped magnetized with a single magnetic pole in the radial direction. Obviously, permanent magnets and cylindrical yokes can be used.
[0021]
Furthermore, the driving method of the present invention can be applied to either a bipolar bridge circuit or a unipolar circuit, and the input waveform for driving may be either a sine wave or a square wave, and is selected in consideration of cost / performance. .
[0022]
【The invention's effect】
According to the present invention, it is possible to easily realize a vibrating body for a portable device having a simple configuration, good cost / performance, silence, and excellent bodily sensation characteristics.
[0023]
Further, according to the present invention, since a direct current motor is not used, it is not necessary to make the life and quality maintenance between brushes and commutators peculiar to direct current motors difficult, so that production management is easy.
[0024]
In addition, according to the present invention, since the resonance of the driver is used, it is possible to realize a small and high-performance vibrating body with high motion conversion efficiency.
[0025]
Further, according to the present invention, it takes less time to start up like a normal vibration motor, it is possible to play a rhythm in accordance with music, and the functions of portable devices can be enriched.
[0026]
In addition, according to the present invention, the magnetic circuit of the driver is well closed between the cylindrical yoke and the columnar permanent magnet, so that there is little leakage magnetic flux and electromagnetic interference to the device on which the vibrating body of the present invention is mounted is prevented. It can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a half sectional view of a configuration of an axially driven vibrator according to the present invention.
2 is a cross-sectional view taken along line XX of FIG.
FIG. 3 is a cross-sectional view of another embodiment of the present invention.
FIG. 4 is a diagram illustrating the configuration of another driver element of the present invention.
FIG. 5 is a configuration diagram of a vibration motor using a shaft length type DC motor having a brush and a commutator of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Vibrator 11 Frame 12 Drive coil 13 Coil bobbins 14a, 14b, 14c, 15a, 15b, 15c, 41a, 41b, 41c Guide convex part 20, 30 Driver 21 Cup-shaped yoke 22 Cylindrical permanent magnet 23 Weight 24 25 Coil spring 26, 27 Air gap 28 Pole piece 31a, 31b, 31c Guide groove 35, 36 Terminal

Claims (2)

A cylindrical drive coil is fixed to one end of the cylindrical frame, and a cup-shaped yoke made of a magnetic material that is magnetically engaged with the drive coil via a gap, and one end is fixed inside the cup-shaped yoke. In an axially driven vibrating body composed of a driver having a cylindrical permanent magnet and a weight mounted thereon and a pair of coil springs elastically supporting the driver, a shaft is provided on the inner peripheral surface of the frame. A plurality of rows of guide projections parallel to the direction are provided, and a plurality of rows of guide grooves that are mechanically slidably engaged with the guide projections are provided on the outer peripheral surface of the driver parallel to the axial direction, and the drive coils are concentric. It is set between the cup-shaped yoke and the columnar magnet via a cylindrical gap, and the driver is arranged to vibrate in the axial direction by a pair of coil springs provided on both side ends of the frame. An axially driven vibrator characterized by the above. 2. The axially driven vibrator according to claim 1, wherein a cylindrical pole piece made of a magnetic material is fixed to the other end of the cylindrical magnet contained in the cup-shaped yoke of the driver. .

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