JP2004195444A - Electromagnetic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic actuator capable of adjusting a resonant frequency in a manufacturing process. <P>SOLUTION: The electromagnetic actuator 1 has a magnet 7, a pole piece 9 mounted on the magnet 7, a yoke 31, a weight 11 fixed to the yoke 31 together with a spring 17, a base 13 equipped with an outside terminal 51 and an inside terminal 52, a coil 3 mounted on the base 13, and a spring cover 61 for pressing the spring 17 on the base 13. In the actuator 1, an outside end terminal 17b of the spring 17 is slidably fixed, and after adjusting, the resonance frequency is finally fixed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic actuator used for a mobile phone, a pager, or the like, for notifying a call at the time of signal reception by vibration.
[0002]
[Prior art]
As this type of electromagnetic actuator, one disclosed in WO 99/39843 is known. FIG. 3 shows this electromagnetic actuator. As shown in FIG. 3, in the electromagnetic actuator 100, in a case 101, a magnet 105 is arranged in a groove of a yoke 103, and a coil 109 is located in the groove with a gap between the magnet 105 and attached to a diaphragm 107. The yoke 103 is supported by upper and lower diaphragms 111 and 113 disposed in parallel with the side surface of the housing 101. By applying a low-frequency current to the coil 109, the yoke 103 vibrates due to 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 high-frequency sound. In addition, a flange 115 is arranged from the case 101 toward the inside radial direction, and regulates the vibration direction of the yoke 103 in the vertical direction.
[0003]
[Problems to be solved by the invention]
However, the above-described technique has a problem in that the resonance frequency varies due to the weight of the yoke 103 and the dimensions of the diaphragms 111 and 113.
[0004]
Therefore, an object of the present invention is to provide an electromagnetic actuator that can adjust a resonance frequency in a 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 mounted on the magnet, a yoke facing the pole piece, a weight mounted on the yoke, a spring supporting the weight at its inner end, an outer terminal and an inner terminal. Equipped with a base, a coil mounted on the base, and a spring cover for pressing the outer end of the spring against the base.The coil is arranged in the gap between the pole piece and the yoke, and the inner terminal and the outer terminal are connected to the coil. In an electromagnetic actuator in which a weight oscillates when an alternating current is applied,
The outer end of the spring is slidably fixed, and finally fixed after adjusting the resonance frequency.
[0006]
According to the first aspect of the present invention, since the outer end of the spring is slidably fixed, and the resonance frequency is adjusted and finally fixed, 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 present invention, the outer end of the spring is exposed by exposing the outermost end thereof through a groove provided in the base, and the outermost end is slid to cause resonance. The frequency is adjusted.
[0008]
According to the second aspect of the invention, the same operation and effect as those of the first aspect of the invention can be obtained, and the resonance frequency can be adjusted in the final manufacturing process, so that the adjustment process can be simplified.
[0009]
According to a third aspect of the present invention, in the first aspect of the present invention, the outer terminal and the inner terminal are fitted and fixed to the base so that the bottom surface is on the same plane.
[0010]
According to the third aspect of the present invention, the same effects as those of the first or second aspect can be obtained, and the outer terminal and the inner terminal are formed on the same bottom surface. It can be soldered to the printed circuit board by passing.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a 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 informs a carrier of information received through a mobile phone by vibration.
[0012]
The electromagnetic actuator 1 has a base including a magnet 7, a pole piece 9, a yoke 31, a weight 11 fixed to the yoke 31 together with the inner end 17a of the spring 17, and an outer terminal 51 and an inner terminal 52 which are conductors. 13, a coil 3 mounted on the upright portion 13a of the base 13, a spring cover 61 for pressing the outer end 17b of the spring 17 against the base 13, and a cover 14 for housing these. The coil 3 is connected to the outer terminal 51 and the inner terminal 52, and by applying an alternating current, the weight 11 vibrates up and down in FIG. In this specification, the terms above and below are used for convenience, but do 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 made of a metal material such as stainless steel. Notches are provided at three locations in the circumferential direction on the inner end 17a, and are fitted with three projections provided on the inner circumference of the weight 11. The circumferential portion 11a of the weight 11 is bonded and fixed to the outer surface of the outer wall 31a of the yoke 31, and the lug 31b provided on the outer periphery of the yoke 31 is fixed by sandwiching the inner end 17a of the spring 17 between the weight 11 and the spring. The outer end 17b of the spring 17 has the outermost ends 17b1 (three places) extending downward at the ends.
[0015]
The base 13 is a resin molded product. The base 13 is provided with an upright portion 13a that rises upward at the center. The center of the lower bottom is fitted (press-fitted) with the inner terminal 52, and the outer terminal 51 is mounted and fixed on 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 the inside is connected to the coil 3 to apply an alternating current. The inner terminal 52 has a circular shape, and the outer terminal 51 has a donut flat shape. When the outer terminal 51 is fitted to the base 13, it forms the bottom surface of the electromagnetic actuator 1, and this bottom surface is located on the same plane.
[0016]
The coil 3 is mounted on the outer peripheral surface of the upright portion 13a, and one lead wire of the coil 3 is soldered to the inner surface (upper surface) of the inner terminal 52 via a slit provided in the upright portion 13a. The outer peripheral portion (one location) of the outer terminal 51 stands up and penetrates the base 13. The other lead wire of the coil 3 is soldered to the upright portion along the upper surface of the base 13.
[0017]
The spring 17, to which the weight 11, the yoke 31, the magnet 7, and the pole piece 9 are fixed, is fitted into the base 13 with its outermost end 17b1 penetrating through grooves 13b (three places) provided in the base 13. The groove 13b has a width of about 10 degrees in the circumferential direction (angular direction).
[0018]
The ring-shaped metal spring cover 61 is provided with retainers 61a (three places) projecting inward at the upper part, and holes 61b (three places) on the side surface. The hole 61b is fitted with a projection provided on the base 13. By fitting the spring cover 61 into the base 13 while fitting the spring cover 61 into the base 13, the presser 61 a presses the outer end 17 b of the spring 17 against the base 13.
[0019]
The cover 14 covers the whole from above by fitting with the outermost peripheral portion of the base 13. The bottom portion is covered with the base 13, the outer terminal 51, and the inner terminal 52, and the outermost ends 17b1 (three places) of the spring 17 protrude from the grooves 13b (three places) on the outer peripheral portion.
[0020]
The spring constant of the spring 17 and the total mass of the weight 11 and the yoke 31, the magnet 7, and the pole piece 9 constitute a mechanical vibration system, and the resonance frequency is made to 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, and when an alternating current is applied to the coil 3, an electromagnetic force acts, and the weight 11 fixed to the yoke 31 moves in the vertical direction. Vibrate. In order to secure the vertical vibration amplitude, a space is provided 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 lug 31b of the yoke 31 and the outer terminal 51. At the same time, three weight reliefs 11b 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 at the same time. The weight 11 and the yoke 31 fixed to the inner end 17a also rotate. Note that the inner end 17a is firmly fixed in the rotation direction since it is sandwiched between the protrusions of the weight 11 by being fitted therewith.
[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 amount of vibration. 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 17b1 is slid, the length of the outer end 17b up 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 since it is sufficient to mainly cover the variation in the weight of the weight 11 and the variation in the dimensions of the spring 17.
[0024]
As described above, the vibration system can be adjusted to a predetermined resonance frequency by sliding the extreme end 17b1 while applying a single-frequency alternating current and measuring the vibration amount. After the adjustment, the protruding portion of the outermost 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 mobile phone. When an alternating current of a single frequency is supplied from the printed circuit board, the electromagnetic actuator 1 resonates and vibrates at the frequency, and informs the wearer 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]
Since the individual electromagnetic actuators 1 have variations in the resonance frequency due to variations that are inevitable in manufacturing, the vibration amount is reduced by the variation as it is.
[0028]
In the present embodiment, since the resonance frequency of the vibration system can be adjusted to a predetermined value by sliding the outermost end portion 17b1 of the spring 17, the resonance of all the electromagnetic actuators 1 obtained from the manufacturing line can be adjusted. The maximum vibration amount can be output by matching the frequencies.
[0029]
Further, in the present embodiment, since the resonance frequency can be adjusted in the state of measuring the amount of vibration which is the final manufacturing process of the electromagnetic actuator 1, the process can be prevented from becoming complicated. At the same time, the outermost end 17b1 can be realized inexpensively because the end of the spring 17 is simply extended, and the operation can be performed simply because the adjustment is a simple sliding operation.
[0030]
Further, in the present embodiment, the outer terminal 51 and the inner terminal 52 that are fitted and fixed to the base 13 are on the same bottom surface, so that cream solder or the like is applied to the AC current supply pattern of a printed circuit board such as a mobile phone. If it is mounted via an automatic solder bath, it can be easily fixed and connected to a printed circuit board without manual work.
[0031]
In the embodiment of the present invention, a vibration actuator has been described. However, the present invention is not limited to this, and it goes without saying that the present invention can be effectively applied to an electromagnetic actuator that generates both vibration and sound.
[0032]
【The invention's effect】
According to the first aspect of the present invention, the resonance frequency can be adjusted during the assembling process, so that the variation in the resonance frequency can be suppressed and a large vibration amount can be obtained.
[0033]
According to the second aspect of the invention, the same effects as those of the first aspect of the invention can be obtained, and the resonance frequency can be adjusted in the final manufacturing process, so that the adjusting process can be simplified and the manufacturing cost can be reduced. can do.
[0034]
According to the third aspect of the invention, the same effects as those of the first and second aspects of the invention can be obtained, and the fixing and connection to the printed circuit board can be performed by passing through the automatic solder bath.
[Brief description of the drawings]
FIG. 1 is a 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 of FIG.
FIG. 3 is a cross-sectional view showing a conventional electromagnetic actuator.
[Explanation of symbols]
DESCRIPTION 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 equipped with the outer and inner terminals, and attached to the base And a spring cover that presses the outer end of the spring to the base.The coil is placed in the gap where the pole piece and the yoke face each other, and the weight is applied by applying alternating current to the coil from the inner terminal and the outer terminal. In a vibrating electromagnetic actuator,
An electromagnetic actuator wherein an outer end of a spring is slidably fixed, and a resonance frequency is adjusted and finally fixed. 2. The electromagnetic actuator according to claim 1, wherein the outer end of the spring is exposed at its extreme end through a groove provided in the base, and the resonant frequency is adjusted by sliding the extreme end. . The electromagnetic actuator according to any one of claims 1 to 2, wherein the outer terminal and the inner terminal are fitted and fixed to the base so as to be on the same bottom surface.

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