JP3950043B2 - Electromagnetic actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic actuator that is used in a mobile phone, a pager, and the like and notifies a call when a signal arrives by vibration.
[0002]
[Prior art]
As this type of electromagnetic actuator, one disclosed in WO99 / 39843 is known. This electromagnetic actuator is shown in FIG. As shown in FIG. 3, in the electromagnetic actuator 100, the magnet 105 is disposed in the groove portion of the yoke 103 in the case 101, and the coil 109 is located in the groove portion through the gap with the magnet 105 and attached to the diaphragm 107. The yoke 103 is supported by upper and lower diaphragms 111 and 113 arranged in parallel to the side surface of the housing 101. By applying a low frequency current to the coil 109, the yoke 103 vibrates by the action of the diaphragms 111 and 113, and by applying a high frequency current to the coil 109, the diaphragm 107 is vibrated to generate a high frequency sound. Further, a flange 115 is arranged from the case 101 toward the inner radial direction, and the vibration direction of the yoke 103 is restricted in the vertical direction.
[0003]
[Problems to be solved by the invention]
However, the above-described technique has a problem that the resonance frequency varies due to variations in the weight of the yoke 103 and the dimensions of the diaphragms 111 and 113.
[0004]
Accordingly, an object of the present invention is to provide an electromagnetic actuator that can adjust the resonance frequency during the manufacturing process and can be soldered to a printed circuit board by passing through an automatic solder bath.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 includes a magnet, a pole piece attached to the magnet, a yoke facing the pole piece, a weight attached to the yoke, a spring for supporting the weight at its inner end, an outer terminal and an inner terminal. , A coil attached to the base, and a spring cover that presses the outer end of the spring against the base. The coil is arranged in a gap where the pole piece and the yoke face each other, and the coil is arranged from the inner terminal and the outer terminal to the coil. In an electromagnetic actuator in which a weight vibrates by applying an alternating current,
The outer end of the spring is slidably fixed, and finally fixed after adjusting the resonance frequency.
[0006]
In the first aspect of the invention, the outer end of the spring is slidably fixed, and the resonance frequency is finally fixed after adjustment, so that the resonance frequency can be adjusted in the assembly process. Can be suppressed.
[0007]
According to a second aspect of the present invention, in the first aspect of the invention, the outer end of the spring is exposed through the groove provided in the base, and is resonated by sliding the outermost portion. The frequency is adjusted.
[0008]
According to the second aspect of the invention, the same effect as that of the first aspect of the invention can be achieved, and the resonance frequency can be adjusted in the final manufacturing process, so that the adjustment process can be simplified.
[0009]
The invention according to claim 3 is characterized in that, in the invention according to any one of claims 1 to 2, the outer terminal and the inner terminal are fitted and fixed to the base so as to be a bottom surface on the same plane.
[0010]
In the invention according to the third aspect, the same effect as the invention according to any one of the first and second aspects can be obtained, and the outer terminal and the inner terminal are provided on the same plane. By passing it, it can be soldered to the printed circuit board.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an electromagnetic actuator according to the present invention, and FIG. 2 is an exploded perspective view of the electromagnetic actuator of FIG. The electromagnetic actuator 1 shown in FIG. 1 notifies a user of information received through a mobile phone by vibration.
[0012]
The electromagnetic actuator 1 includes a magnet 7, a pole piece 9, a yoke 31, a weight 11 fixed to the yoke 31 together with the inner end 17 a of the spring 17, a base including an outer terminal 51 and an inner terminal 52 that are conductors. 13, the coil 3 attached to the upright portion 13 a of the base 13, a spring cover 61 that presses the outer end 17 b of the spring 17 against the base 13, and a cover 14 that houses them. The coil 3 is connected to the outer terminal 51 and the inner terminal 52, and the weight 11 vibrates in the vertical direction in FIG. 1 by applying an alternating current. In the present specification, the upper and lower terms are used for convenience, but this does not specify the vertical direction.
[0013]
The disc-shaped magnet 7 is magnetized in the vertical direction, and the pole piece 9 is fixed (adhered) to one end (for example, S pole), and the one end (for example, N pole) is fixed (adhered) to the center of the yoke 31.
[0014]
The spring 17 is a leaf spring using a metal material such as stainless steel, and the inner end 17 a is provided with notches at three locations in the circumferential direction and mated with three projecting portions provided on the inner periphery of the weight 11. The circumferential portion 11 a of the weight 11 is bonded and fixed to the outer surface of the outer wall 31 a of the yoke 31, and the ear portion 31 b provided on the outer periphery of the yoke 31 is fixed by sandwiching the inner end 17 a of the spring 17 between the weight 11. The outer end 17b of the spring 17 is provided with outermost ends 17b1 (three places) extending downward at the ends.
[0015]
The base 13 is a resin molded product, and includes a rising portion 13a that rises upward at the center, the center of the lower bottom portion is fitted (press-fitted) with the inner terminal 52, and the outer terminal 51 is attached and fixed to the outer periphery. The outer terminal 51 and the inner terminal 52 are made of a conductive metal material, the bottom is connected to an external printed circuit board, and is connected to the coil 3 inside to be applied with an alternating current. The inner terminal 52 has a circular shape, and the outer terminal 51 has a donut flat plate shape. When the inner terminal 52 is fitted to the base 13, it forms a bottom surface of the electromagnetic actuator 1, and the bottom surface is located on the same plane.
[0016]
The coil 3 is mounted on the outer peripheral surface of the standing portion 13a, and one lead wire of the coil 3 is soldered to the inner surface (upper surface) of the inner terminal 52 through a slit provided in the standing portion 13a. The outer peripheral portion (one place) of the outer terminal 51 stands upward and penetrates the base 13. The other lead wire of the coil 3 is soldered to this rising portion along the upper surface of the base 13.
[0017]
The weight 11, the yoke 31, and the spring 17 to which the magnet 7 and the pole piece 9 are fixed are fitted into the base 13 while passing through the grooves 13 b (three places) provided in the base 13 at the end 17 b 1. The groove 13b is provided with a width of about 10 degrees in the circumferential direction (angular direction).
[0018]
The ring-shaped metal spring cover 61 is provided with pressers 61a (three places) projecting inwardly at the top, and holes 61b (three places) are provided on the side surface. The hole 61 b is fitted with a protrusion provided on the base 13. By fitting the spring cover 61 with the base 13 while fitting, the presser 61 a presses and holds the outer end 17 b of the spring 17 against the base 13.
[0019]
The cover 14 is fitted with the outermost peripheral portion of the base 13 and covers the whole from the top. The bottom is covered with the base 13, the outer terminal 51, and the inner terminal 52, and the outermost end 17b1 (three places) of the spring 17 protrudes from the groove 13b (three places) on the outer peripheral portion.
[0020]
The spring constant of the spring 17 and the total mass of the weight 11, the yoke 31, the magnet 7, and the pole piece 9 constitute a mechanical vibration system, and the resonance frequency should match the frequency of the alternating current applied to the coil 3. Is desirable.
[0021]
The weight 11 is formed by sintering powder of a high specific gravity material such as tungsten. When an alternating current is applied to the coil 3, an electromagnetic force is applied, and the weight 11 fixed to the yoke 31 is moved in the vertical direction. Vibrate. In order to ensure vertical vibration amplitude, there is a space between the upper surface of the yoke 31 and the cover 14, between the lower surface of the pole piece 9 and the base 13, and between the lower surface of the ear 31 b of the yoke 31 and the outer terminal 51. In addition, three meat reliefs 11 b are provided on the outer periphery of the weight 11.
[0022]
Although the outer end 17b of the spring 17 is pressed by the presser 61a, when the outermost end 17b1 protruding to the bottom is slid in the circumferential direction (angular direction) along the groove 13b, the outer end 17b rotates and simultaneously The weight 11 and the yoke 31 fixed to the inner end 17a also rotate. Since the inner end 17a is sandwiched by fitting with the protrusion of the weight 11, it is strongly fixed in the rotational direction.
[0023]
In the manufacturing process, a single frequency alternating current is applied to the outer terminal 51 and the inner terminal 52 from the outside to measure the vibration amount. When the frequency of the applied current is changed, the amount of vibration changes according to the resonance characteristics of the vibration system. Similarly, when the outermost end portion 17b1 is slid, the length of the outer end 17b to the presser 61a changes, so that the resonance frequency of the vibration system changes. The amount of change due to the slide may be small because it mainly covers the variation in the weight of the weight 11 and the variation in the dimensions of the spring 17.
[0024]
In this way, the vibration system can be adjusted to a predetermined resonance frequency by sliding the outermost end portion 17b1 while measuring the amount of vibration by applying an alternating current of a single frequency. After the adjustment, the protruding portion of the outermost end portion 17b1 is cut and fixed with an adhesive at the portion of the groove 13b.
[0025]
Next, the operation of the present embodiment will be described based on the above-described configuration and manufacturing process.
[0026]
The electromagnetic actuator 1 is mounted on a printed circuit board such as a cellular phone. When an alternating current of a single frequency is supplied from the printed circuit board, the electromagnetic actuator 1 resonates and vibrates at that frequency, and informs the user of information such as an incoming call. The resonance frequency of the vibration system is determined by the spring constant of the spring 17 and the total mass of the weight 11 and the like.
[0027]
Due to variations that are unavoidable in manufacturing, the individual electromagnetic actuators 1 have variations in the resonance frequency, so that the vibration amount is reduced by the variation as it is.
[0028]
In the present embodiment, the resonance frequency of all the electromagnetic actuators 1 obtained from the production line can be adjusted by sliding the outermost end portion 17b1 of the spring 17 to adjust the resonance frequency of the vibration system to a predetermined value. The maximum vibration amount can be output by matching the frequencies.
[0029]
Further, in the present embodiment, the resonance frequency can be adjusted in the measurement state of the vibration amount that is the final manufacturing process of the electromagnetic actuator 1, so that the process can be prevented from becoming complicated. At the same time, since the end 17b1 is simply an extension of the end of the spring 17, it can be realized at a low cost, and the adjustment is a simple slide operation, so that the operation can be easily performed.
[0030]
Furthermore, in the present embodiment, the outer terminal 51 and the inner terminal 52 that are fitted and fixed to the base 13 are the bottom surfaces on the same plane, so that cream solder or the like is applied to the alternating current supply pattern of a printed circuit board such as a cellular phone. Mounting and passing through the automatic solder bath, it is possible to easily fix and connect to the printed circuit board without manual work.
[0031]
In the embodiment of the present invention, the vibration actuator has been described. However, the present invention is not limited to this, and it goes without saying that the present invention can also be effectively applied to an electromagnetic actuator that generates both vibration and sound.
[0032]
【The invention's effect】
In the first aspect of the invention, the resonance frequency can be adjusted during the assembly process, so that a large amount of vibration can be obtained while suppressing variations in the resonance frequency.
[0033]
The invention described in claim 2 has the same effect as that of the invention described in claim 1, and the resonance frequency can be adjusted in the final manufacturing process, so that the adjustment process can be simplified and the manufacturing cost can be reduced. can do.
[0034]
The invention described in claim 3 can achieve the same effect as that of the invention described in any one of claims 1 to 2, and can be fixed and connected to the printed circuit board by passing through an automatic solder bath.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an electromagnetic actuator according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the electromagnetic actuator shown in FIG.
FIG. 3 is a cross-sectional view showing a conventional electromagnetic actuator.
[Explanation of symbols]
1 Electromagnetic Actuator 3 Coil 7 Magnet 9 Pole Piece 11 Weight 13 Base 14 Cover 17 Spring 31 Yoke 51 Outer Terminal 52 Inner Terminal 61 Spring Cover

Claims (3)

A magnet, a pole piece attached to the magnet, a yoke facing the pole piece, a weight attached to the yoke, a spring supporting the weight at its inner end, a base attached to the outer terminal and the inner terminal, and attached to the base And a spring cover that presses the outer end of the spring against the base, the coil is disposed in the gap where the pole piece and the yoke are opposed, and the weight is applied by applying an alternating current to the coil from the inner and outer terminals. In an electromagnetic actuator that vibrates,
An electromagnetic actuator characterized in that an outer end of a spring is slidably fixed and finally fixed after adjusting a resonance frequency. 2. The electromagnetic actuator according to claim 1, wherein the outer end of the spring is exposed through a groove provided in the base at the outermost end, and the resonance frequency is adjusted by sliding the outermost end. . 3. The electromagnetic actuator according to claim 1, wherein the outer terminal and the inner terminal are fitted and fixed to the base so as to be a bottom surface on the same plane.

Images