KR20140096230A - Vibrator for linear vibration moter and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a vibrator for a linear vibration motor and a manufacturing method thereof. More specifically, the vibrator for a linear vibration motor comprises: a yoke included in a frame, having a middle part sunken downwards to have an installation space part, having a first insertion hole formed on a sunken bottom surface, and having a plurality of injection grooves formed from the middle part of a lower side surface towards an outer circumference at regular intervals in a circumferential direction; a plate having an injection space part formed between the yoke and the plate by a die having a second injection hole formed thereon; a mass body enveloping the outer side of the yoke; a main magnet injected integrally with the yoke, the plate and the mass body by mixing a magnetic body having a certain size with melted plastic and injecting the magnetic body into the injection space part and the injection grooves through the first injection hole and the second injection hole; a submagnet combined with the upper side of the plate; and a spring having elasticity, having one end part coupled to a part not having the injection grooves formed thereon of the lower side surface of the yoke, and having the other end part inserted into the inner side surface of the frame. The present invention, as specified above, can improve work efficiency by integrally molding the yoke and the plate in the molding process of the main magnet thus reducing coupling processes and operation time; can reduce the costs by reducing the operation processes thus reducing a necessary space; and can improve vibration efficiency by increasing the coupling force and the weight thus ensuring magnetic force by high vibration.

Description

Technical Field [0001] The present invention relates to a vibrator for a linear vibration motor,

More particularly, the present invention relates to a vibrator, and more particularly, to a vibration motor, a part of each of the components, which are separately manufactured and joined together, is integrally formed, thereby reducing the number of work processes, thereby reducing work time and cost, The present invention relates to a vibrator for a linear vibration motor and a method of manufacturing the same.

In general, the sound heard by the ear is a wave created by the vibration of an object, a special form of kinetic energy that arises when an atom moves in a regular pattern.

Various acoustical instruments used in real life use kinetic energy of electrons moving when electric current flows in the electric wire, and vibration caused by such kinetic energy is generated, and the vibration is transmitted to the outside or outputted as occasion demands.

A commonly used mobile phone is configured to output sound and vibration, and a vibration motor is provided together with such a speaker to output vibration to the outside.

A conventional vibration motor (linear vibration actuator) includes a moving part made of a mass having a predetermined mass attached to a yoke and a yoke surrounding the magnet, as disclosed in Japanese Patent No. 10-0550904, And a coil assembly disposed on the base assembly.

And a plate spring integrated case having a cylindrical side surface portion and a top surface portion connected to the side surface portion and formed by a leaf spring partly contacting the upper surface of the motion portion.

Here, the moving part is composed of a magnet, a plate, a yoke, and a mass, and the magnet, the plate, the yoke, and the mass body are respectively manufactured and sequentially bonded, and a plurality of operators are sequentially bonded to each other.

In this way, when a plurality of workers join each constitution step by step, the fatigue due to the simple labor of the worker accumulates, so that the work efficiency is lowered with the elapse of time and the failure can be caused.

Of course, the defective rate can be lowered by a skilled worker. However, since the vibration motor is used in portable devices such as an earphone, a mobile phone, and a game machine, it is small and the size of the magnet, plate, yoke, There is a problem that the incidence of defects is high even when assembled with a small machine.

Particularly, as the concentricity of the magnet and the plate becomes more than the allowable value, an eccentric magnetic field is formed to cause defects such as defects such as detachment due to poor bonding strength and the like.

These defects can not be sold because the defects are unconditionally produced in subsequent processes even if any one of the bonding processes is mistaken. Particularly, in the case of sensitive magnets, plates, yokes and masses, And to develop a technique that can improve the working efficiency.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method of manufacturing a magnet, which includes a first injection hole and a plate having a second injection hole formed therein, It is possible to reduce work process time, work time, cost, and mutual bonding force as compared with the prior art, so that it is possible to secure the magnetic force due to the high vibration by increasing the weight, And a method for manufacturing the same.

According to an aspect of the present invention, there is provided an injection molding machine including a first injection hole formed at a bottom surface of a recessed portion protruding downward from a central portion thereof, and a plurality of injection holes formed in a circumferential direction at a lower- A plate having a second injection hole formed therein to surround the yoke and spaced a predetermined distance apart from the yoke to form an injection space between the yoke and the yoke, a mass having a predetermined mass, And a main magnet which is injected into the injection space and the injection groove and injected into the yoke, the plate, and the mass body integrally with each other when the magnetic body of a predetermined size is mixed with the melted molten material, and when the main magnet is injected, A coil provided in the frame cover of the vibration motor is positioned between the inner surface of the recessed central portion of the yoke And forms a reaction space part. The vibration space is formed inside the frame forming the outer shape of the vibration motor, and vibrates in response to the vibration of the coil.

Preferably, the yoke has a coupling protrusion protruded along an upper outer peripheral surface, and a coupling groove is formed inside the mass to correspond to the coupling protrusion.

In addition, the first injection hole of the yoke is inclined outwardly toward the lower side in the installation space portion, the cross-sectional area gradually increases, and the main magnet injected into the first injection hole and the installation space portion, So that the bonding force is improved.

In addition, the second injection hole of the plate is inclined outward toward the upper side, so that the main magnet is integrally coupled to the second injection hole to improve the coupling force.

The main magnet is injected through at least one selected from the first injection hole and the second injection hole.

The magnetic material of the main magnet may be at least one selected from the group consisting of Sm, Fe, barium ferrite, strontium ferrite, neodymium (Nd) and cobalt cobalt.

In addition, the mass body may have an extended injection groove formed at a portion thereof contacting the lower end of the yoke formed with the injection groove, the extended injection groove being formed to be larger than the depth of the injection groove, and the main magnet, As well as up to the lower end of the outer circumferential surface of the yoke as it is filled up to the extended injection groove.

Further, a sub-magnet is further provided on the upper side of the plate.

The sub-magnet is formed by sintering neodymium (Nd).

The lower end polarity of the sub-magnet is the same as the upper end polarity of the tangential main magnet, so that mutual repulsive force acts.

In the plate, a seating space is formed at the center so that the sub-magnet is seated.

In addition, the injection grooves of the yokes are formed in a straight line with the same width, or the width thereof is changed and formed along a straight line, or the same width or width is changed and spirally formed.

A second sub-magnet is further provided between the yoke and the mass body.

Further, the second sub-magnet is installed in place of a part of the mass body, so that the outer shape of the mass body is maintained.

The integrally formed yokes, plates, masses and main magnet are retracted in the frame by a spring, the spring is resilient, and one end is joined to a portion of the lower side of the yoke where injection grooves are not formed And the other end is fitted to the inner side surface of the frame, and one end is positioned above the other end such that the yoke is spaced apart from the bottom surface of the frame.

Further, the spring is joined to the yoke by laser welding.

The spring includes a first spring frame connected to the yoke, a second spring frame spaced apart from the first frame and fixed to the frame, and a second spring frame connected spirally between the first spring frame and the second spring frame And includes a plurality of elastic portions.

In addition, the spring is formed along a straight line or in a spiral shape when viewed in a plan view.

Placing a plate on a mounting groove of a lower mold having a lower injection hole and projecting a mounting block so as to form a mounting groove on a central portion thereof; mounting a yoke having a plurality of injection holes formed on the lower surface thereof to a mounting block of the lower mold A step of mounting a mass on the outer side of the stationary yoke, a step of covering an upper mold having an upper injection hole formed thereon with a lower mold to which the yoke is fixed, and a step of mixing the magnetic material through at least one of the lower injection hole and the upper injection hole A step of forming a main magnet integrally with the plate, the yoke, and the mass by injecting the melted melted material, separating the main magnet integrally formed with the plate and the yoke from the upper mold and the lower mold, Coupling the sub-magnet to the coupled plate, and coupling the sub- And joining one end of the spring to a portion where the injection groove is not formed.

As described above, according to the vibrator for a linear vibration motor and the method of manufacturing the same according to the present invention, since the yoke and the plate are integrally formed when the main magnet is formed, the joining process and the working time can be shortened, As the work process is reduced, the space required is reduced to reduce the cost, and the mutual bonding force can also be improved, so that the magnetic force can be secured by the high vibration by increasing the weight, It is a very useful and effective invention.

1 is a view showing a vibrator for a linear vibration motor according to the present invention,
Fig. 2 is a view showing a state in which a vibrator for a linear vibration motor according to the present invention is separated,
3 is a view showing a state where the vibrator according to the present invention is engaged with the vibration motor,
4 is a view showing another embodiment of a vibrator for a linear vibration motor according to the present invention,
5 is a view showing a state in which a second sub magnet is further provided in a vibrator for a linear vibration motor according to the present invention,
6 is a view showing an injection groove of a yoke according to the present invention,
7 is a view showing a spring according to the present invention,
8 is a view showing another embodiment of the spring according to the present invention,
9 is a view showing a method of manufacturing a vibrator for a linear vibration motor according to the present invention,
10 is a view showing a manufacturing process of a vibrator for a linear vibration motor according to the present invention,
11 is a view showing an assembled vibrator according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

It should be noted that the present invention is not limited to the scope of the present invention but is only illustrative and various modifications are possible within the scope of the present invention.

FIG. 1 is a view showing a vibrator for a linear vibration motor according to the present invention, FIG. 2 is a view showing a state in which a vibrator for a linear vibration motor according to the present invention is separated, FIG. 3 is a cross- FIG. 4 is a view showing another embodiment of a vibrator for a linear vibration motor according to the present invention, and FIG. 5 is a view showing a state in which a second sub magnet is attached to a vibrator for a linear vibration motor according to the present invention FIG. 6 is a view showing an injection groove of a yoke according to the present invention, FIG. 7 is a view showing a spring according to the present invention, and FIG. 8 is a cross- 9 is a view showing a method of manufacturing a vibrator for a linear vibration motor according to the present invention, and Fig. 10 is a view showing a manufacturing process of a vibrator for a linear vibration motor according to the present invention And, Figure 11 is a diagram illustrating a lean assembled transducer in accordance with the present invention.

As shown in the figure, a vibrator 10 for a linear vibration motor is composed of a yoke 100, a plate 200, a main magnet 300, and a mass body 400.

First, the yoke 100 is provided inside a frame 20 having a frame cover 40 on which a coil 30 is formed. The center portion of the yoke 100 is recessed so as to protrude downward, A hole 120 is formed.

In addition, the yoke 100 has a plurality of injection grooves 130 formed in the circumferential direction at the center of the lower side surface at a predetermined interval along the circumferential direction.

It is preferable that the yoke 100 has a coupling protrusion 140 protruding along the upper peripheral surface and a coupling groove 410 formed inside the mass body 400 to correspond to the coupling protrusion 140 And is made of metal or non-metal, and in one embodiment, made of samarium (SM).

The plate 200 is spaced apart from the yoke 100 by a predetermined distance and a second injection hole 210 is formed to define an injection space 110 between the yoke 100 and the plate 200 do.

The injection space part 110 is formed not only by the yoke 100 and the plate 200 but also by the injection space part 110 in which the four sides are closed as the yoke 100 and the plate 200 are mounted on the mold, .

The mass body 400 is provided to surround the outside of the yoke 100 and is formed to have a certain amount of mass.

It is preferable that the mass body 400 is bonded to the yoke 100 by an adhesive member (not shown). In one embodiment, the mass body 400 is made of tungsten.

The main magnet 300 mixes and ejects the magnetic substance 310 having a predetermined size with magnetism into the molten melt 320 in a state where the injection space portion 110 is formed, 200, and mass body 400, respectively.

In other words, after the magnet body 310 of a predetermined size is mixed with the melted material 320 in the melted state, the magnetic material 310 is melted through the first injection hole 120 of the yoke 100 or the second injection hole 210 of the plate 200 And injected and molded together with the yoke 100 and the plate 200.

A reaction space part 150 for placing the coil 30 provided in the frame cover 40 of the vibration motor between the inner surface of the depressed central part of the yoke 100 and the inner surface of the depressed central part of the yoke 100 when the main magnet 300 is injected, .

The molten material 320 in a molten state in which the magnetic material 310 is mixed may be injected through at least one of the first injection hole 120 and the second injection hole 210. In one embodiment, And the gas in the injection space part 110 is discharged through the second injection hole 210 and the main magnet 300 is injected.

Of course, the gas may be injected through the second injection hole 210, the gas may be discharged through the first injection hole 120, and may be simultaneously injected and discharged through the first injection hole 120 and the second injection hole 210 Gas discharge may also occur.

Here, the first injection hole 120 of the yoke 100 is formed to be inclined outward from the installation space 110 toward the lower side, and the sectional area gradually increases from the upper side to the lower side.

The first injection hole 120 is provided to improve the coupling force with the main magnet 300. The first injection hole 120 is injected through the first injection hole 120 in a molten state and then the lower end of the solidified main magnet 300 is injected into the first injection hole 120, And is formed so as to correspond to the inclined inner surface of the injection hole 120 and is injected in the engaged state, the bonding force is further improved.

The second injection hole 210 of the plate 200 is formed to be inclined outward toward the upper side, and the sectional area gradually increases from the lower side to the upper side.

The second injection hole 210 is for injecting molten material through the second injection hole 210 and then the upper end of the solidified main magnet 300 is inserted into the second injection hole 210, And is formed so as to correspond to the inclined inner surface of the injection hole 210 and is injected in the engaged state, the bonding force is further improved.

Here, the magnetic substance 310 of the main magnet 300 is at least one selected from the group consisting of Sm, Fe, barium ferrite, strontium ferrite, neodymium (Nd), and cobalt hydrate, To the molten melt 320.

At this time, the magnetic material 310 of the main magnet 300 may be made of a magnetic material having its own magnetism, or may be magnetized as necessary through a device capable of imparting magnetism.

The melt 320 is made of plastic or rubber, and a molten material that can be solidified after cooling can be used.

A sub magnet 500 is further provided on the upper side of the plate 200. The sub magnet 500 is coupled to the upper side of the plate 200 integrally projected on the upper side of the main magnet 300, (Not shown).

The plate 200 is formed with a seating space 220 at the center so that the sub magnet 500 can be seated thereon and the sub magnet 500 is forced into the seating space 220, And at the same time, they can be bonded to each other by interference fit.

The sub-magnet 500 is formed by sintering neodymium (Nd), and may be formed of other materials having magnetism.

At this time, the lower end polarity of the sub magnet 500 is the same as the upper end polarity of the contacting main magnet 300, so that mutual repulsive force acts.

An unstable magnetic field is formed between the main magnet 300 and the sub-magnet 500 by the repulsive force, and a current is applied to the coil, which vibrates in response to the unstable magnetic field.

3, the vibrator 10, in which the yoke 100, the plate 200, the main magnet 300, and the mass body 400 are integrally formed, is installed and used in the vibration motor, Since the integrated magnetic circuit 10 is easily installed inside the frame 20, the conventional processes can be omitted to improve the production time and work efficiency.

Here, the spring 600 is further provided with a spring 600 for resiliently moving the vibrator 10, and the spring 600 has elasticity, and has one end portion at a portion where the injection groove 130 is not formed in the lower side of the yoke 100 And the other end is fitted to the inner side surface of the frame 20.

The spring 600 is installed such that one end of the spring 100 is positioned above the other end so as to be spaced apart from the bottom surface of the frame 20 and is preferably joined to the yoke 100 by laser welding.

4, the mass body 400 further includes an extended injection groove 420 at a portion contacting the lower end of the yoke 100 in which the injection groove 130 is formed.

The extended injection groove 420 is formed to be larger than the formed depth of the injection groove 130. The main magnet 300 is formed by the extended injection groove 420 so that the injection groove 130, To the lower end of the outer circumferential surface of the yoke 100, as shown in FIG.

Thus, the yoke 100, the plate 200, and the mass body 400 can be more firmly joined together with the main magnet 300.

As shown in FIG. 5, a second sub-magnet 700 is further provided between the yoke 100 and the mass body 400.

Since the second sub-magnet 700 is installed in place of a part of the mass body 400, the second sub-magnet 700 can be maintained without deforming the mass of the mass body, and the overall weight can be maintained without fluctuation.

The second sub-magnet 700 reacts with at least one of the main magnet 300 and the sub-magnet 500 to form a magnetic field, thereby applying a current to the coil and vibrating in response to the magnetic field.

Here, when the lower end of the main magnet 300 is an N pole and the upper end is an S pole, the lower end of the sub magnet 500 is an S pole, and the upper end thereof is an N pole, and a repulsive force is generated.

An unstable magnetic field is formed between the main magnet 300 and the sub-magnet 500 by the repulsive force, and a current is applied to the coil, which vibrates in response to the unstable magnetic field.

The poles of the upper and lower ends of the second sub-magnet 700 are formed to be different from the poles of the main magnet 300.

In one embodiment, when the lower end of the main magnet 300 is an N pole and the upper end is an S pole, the lower end of the second sub magnet 700 is an S pole and the upper end is an N pole.

6, the injection grooves 130 of the yoke 100 are formed along a straight line having the same width as viewed in a plane, a width thereof is changed and formed along a straight line, or the same width or width is changed, As shown in FIG.

It is, of course, possible to use selectively depending on the case.

7, the spring 600 is composed of the first spring frame 610, the second spring frame 620, and the elastic portion 630.

The first spring frame 610 is joined to the yoke 100 and the second spring frame 620 is fixed to the frame 20 at a predetermined distance from the first spring frame 610.

A plurality of elastic portions 630 are provided to spirally connect the first spring frame 610 and the second spring frame 620.

The spring 600 allows the oscillator 10 integrally formed with the yoke 100, the plate 200, the mass body 400, and the main magnet 300 to be easily vibrated.

As shown in FIG. 8, the spring 600 'of another embodiment is formed along a straight line or in a spiral shape when viewed from the plane, and can be deformed and vibrated when the vibrator 10 vibrates.

9 to 10, the plate mounting step S10, the yoke mounting step S20, the mass mounting step S30, the upper mold covering step S10, (S40), a main magnet forming step (S50), a separating step (S60), a sub magnet coupling step (S70), and a spring connecting step (S80).

In the plate mounting step S10, the plate 200 is mounted on the lower mold 70. First, the lower mold 70 is protruded from the mounting block 72 so that the mounting groove 74 is formed at the center, A lower injection hole 76 is formed.

Of course, the lower mold 70 may be formed with a gas discharge hole (not shown) depending on the case. The lower discharge hole 76 may be formed only by a gas discharge hole (not shown) 76 and a gas discharge hole may be formed.

It is preferable that a gas discharge hole (not shown) is formed in the upper mold 80 by injecting the molten main magnet 300 when only the lower injection hole 76 is formed in the lower mold 70. [

When only a gas discharge hole (not shown) is formed in the lower mold 70, an upper injection hole 86 is formed in the upper mold 80 so that the molten main magnet 300 is injected.

When the lower injection hole 76 and the gas discharge hole are formed in the lower mold 70, the upper injection hole 86 and the gas discharge hole are formed in the upper metal mold 80 so that the molten main magnet 300 is short- As shown in FIG.

The plate 200 is placed in the mounting groove 72 of the lower mold 70 in the plate mounting step S10.

The yoke 100 is mounted on the stationary block 74 of the lower mold 70 so that the yoke 100 having the plurality of injection grooves 130 formed on the bottom thereof is inserted into the plate 200 An injection space part 130 is formed in which the main magnet 300 can be installed therebetween.

The mass body 400 is fixed to the outer side of the yoke 100 by interference fit or the adhesive member (not shown) is attached to the yoke 100, It is possible to join and mount them.

The upper mold covering step S40 covers the lower mold 70 where the yoke 100 is mounted by the upper mold 80 having the upper injection hole 86. The lower mold 70 and the upper mold 80, So that the main magnet 300 is prepared for injection.

In the main magnet forming step S50, the molten plastic 320 mixed with the magnetic material 310 is injected through at least one of the lower ejection hole 76 and the upper ejection hole 86, (200) and the yoke (100).

In other words, when the molten plastic 320 mixed with the magnetic material 310 is injected through the lower injection hole 76, the molten plastic 320 injected through the second injection hole 220 formed in the plate 200 is injected into the main magnet 300 ) Is injected.

Conversely, when the molten plastic 320 mixed with the magnetic material 310 is injected through the upper injection hole 86, the molten plastic 320 injected through the first injection hole 120 formed in the yoke 100 is injected into the main magnet 300, Lt; / RTI >

When the molten plastic 320 mixed with the magnetic material 310 is simultaneously injected through the lower injection hole 76 and the upper injection hole 86, the first injection hole 120 formed in the yoke 100, The main magnet 300 is simultaneously injected through the second injection hole 220 formed in the main body 200.

Of course, it is a matter of course that the gas existing inside the closed upper mold 80 and the lower mold 70 is discharged through the gas discharge holes formed in the upper mold 80 and the lower mold 70.

In the separation step S60, the main magnet 300 formed integrally with the plate 200, the yoke 100, and the mass body 400 is separated from the upper mold 80 and the lower mold 70.

In the sub-magnet coupling step S70, the sub magnet 500 is coupled to the plate 200 integrally coupled to the main magnet 300, and the sub magnet coupling is preferably performed using an adhesive member (not shown).

The spring joining step S80 joins one end of the spring 600 to a portion of the lower side of the yoke 100 where the injection groove 130 is not formed by laser welding.

Accordingly, only the sub-magnet 500 and the spring 600 are separately joined in a state where the yoke 100, the plate 200, the main magnet 300, and the mass body 400 are integrally formed, It is possible to shorten the working time and improve the working efficiency.

Here, as shown in FIG. 11, a plurality of linear vibrator motor vibrators 10 are arranged in a straight line and assembled into one.

The plurality of assembled oscillators 10 are separately used as needed.

A plurality of yokes 100 are formed on one metal plate formed in the lengthwise direction and a plurality of the yokes 100 and the corresponding plates 200 and the masses 400 can be mounted on the molds 70, 80 and then the main magnet 300 can be assembled into one piece by molding.

Needless to say, it can be used regardless of the method of assembling the plurality of vibrators 10.

10: Oscillator 20: Frame
30: coil 40: diaphragm
70: lower mold 80: upper mold
100: yoke 110: injection space part
120: first injection hole 130: injection groove
140: coupling protrusion 150: reaction space part
200: plate 210: second injection hole
220: seating space part 300: main magnet
310: Magnetic body 320: Melt
400: Mass body 410: Coupling groove
420: Extended injection groove 500: Submagnet
600: spring 700: second sub magnet

Claims (19)

A yoke in which a central portion is protruded downward, a first injection hole is formed in a depressed bottom surface, and a plurality of injection grooves are formed in a circumferential direction at a predetermined interval in a circumferential direction;
A plate having a second injection hole formed therein and spaced apart from the yoke by a predetermined distance to form an injection space between the yoke and the yoke;
A mass provided to surround the outside of the yoke and having a predetermined mass;
And a main magnet which mixes a magnetic substance of a certain size having magnetism with a melt in a molten state and is injected into the injection space and the injection groove and is injected together with the yoke, the plate and the mass,
A reaction space part for placing a coil provided in the frame cover of the vibration motor is formed between the main magnet and the inner side surface of the depressed center part of the yoke when the main magnet is injected,
Wherein the vibrator is vibratably installed in a frame forming an outer shape of the vibration motor and outputs vibration to the outside as it vibrates in response to the coil.
2. The yoke according to claim 1,
Wherein an engaging projection is formed to protrude along an upper outer circumferential surface and an engaging groove is formed on the inner side of the mass body so as to correspond to the engaging projection.
[2] The apparatus of claim 1, wherein the first injection hole of the yoke comprises:
The mounting space portion is inclined outward toward the lower side, the sectional area gradually increases,
Wherein the first injection hole and the main magnet injected into the installation space and solidified are integrally joined to the first injection hole to improve the coupling force.
2. The apparatus of claim 1, wherein the second injection hole of the plate comprises:
And the main magnet is integrally joined to the second injection hole so that the coupling force is improved.
The magnetron according to claim 1,
And the second injection hole is injected through at least one selected from the first injection hole and the second injection hole.
The magnetic sensor according to claim 1, wherein the magnetic body of the main magnet comprises:
Wherein at least one selected from the group consisting of silicon nitride (Sm) and iron (Fe), barium ferrite, strontium ferrite, neodymium (Nd) and hydantoin cobalt.
2. The method of claim 1,
Wherein an extended injection groove is formed in a portion of the yoke having the injection groove formed therein and in contact with a lower end thereof, the extended injection groove is formed to be larger than the depth of the injection groove,
Wherein the main magnet is formed up to the lower end of the outer circumferential surface of the yoke when the main magnet is filled up to the injection groove as well as the injection groove.
The method according to claim 1,
And a sub-magnet is further provided on the upper side of the plate.
9. The sub-magnet according to claim 8,
Wherein the first electrode is formed by sintering neodymium (Nd).
9. The semiconductor device according to claim 8, wherein the lower end polarity of the sub-
And a mutual repulsive force is applied to the main magnet so as to have the same polarity as that of the upper end of the main magnet.
9. The apparatus of claim 8,
And a seating space is formed at a center portion of the sub magnet to seat the sub magnet.
The motorcycle according to claim 1, wherein the injection groove of the yoke
Are formed along a straight line having the same width, or have a width varying along a straight line, or are formed in a high-helix shape having the same width or width.
The method according to claim 1,
And a second sub magnet is further provided between the yoke and the mass body.
14. The sub-magnet according to claim 13, wherein the second sub-
And the outer shape of the mass body is maintained by being installed in place of a part of the mass body.
The method according to claim 1,
The integrally molded yoke, plate, mass, and main magnet are retracted within the frame by a spring,
The spring has elasticity, one end is joined to a portion of the lower side of the yoke where the injection groove is not formed, and the other end is fitted to the inner surface of the frame. And the upper end of the end portion is located above the end portion of the linear vibration motor.
16. The method of claim 15,
And is bonded to the yoke by laser welding.
16. The method of claim 15,
A first spring frame joined to the yoke;
A second spring frame spaced apart from the first frame and fixed to the frame; And
And a plurality of elastic portions provided to spirally connect the first spring frame and the second spring frame.
16. The method of claim 15,
And is formed along a straight line or in a spiral shape when viewed in plan.
Placing a plate on a mounting groove of a lower mold in which a mounting block is protruded to form a mounting groove in a central portion and a lower injection hole is formed;
Mounting a yoke having a plurality of injection grooves on a bottom surface thereof to a mounting block of the lower mold;
Mounting a mass on the outside of the stationary yoke;
Covering an upper mold having an upper injection hole formed therein with a lower mold having the yoke mounted thereon;
Injecting molten melt mixed with a magnetic material through at least one of the lower injection hole and the upper injection hole to form a main magnet integrally with the plate, the yoke, and the mass;
Separating the main magnet integrated with the plate and the yoke from the upper mold and the lower mold;
Coupling a sub magnet to a plate integrally coupled to the main magnet; And
And joining one end portion of the spring to a portion of the lower side surface of the yoke where the injection groove is not formed.

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