KR20140071523A

KR20140071523A - Linear motor

Info

Publication number: KR20140071523A
Application number: KR20120125159A
Authority: KR
Inventors: 강승렬; 윤금영; 김종태
Original assignee: (주)파트론
Priority date: 2012-11-07
Filing date: 2012-11-07
Publication date: 2014-06-12
Also published as: KR101452737B1

Abstract

According to the linear motor of the present invention, it is possible to minimize the outflow of the magnetic field while minimizing the thickness of the linear motor, By maintaining the displacement, an appropriate amount of vibration can be maintained.

Description

Linear motor {LINEAR MOTOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor, and more particularly, to a linear motor in which a magnetic field flowing out to the outside is reduced so as not to affect other elements.

2. Description of the Related Art In recent years, personal portable terminals equipped with a separate stylus pen and equipped with a magnet on a stylus pen have been available for personal mobile terminals employing a touch screen method. In this way, determining whether the stylus pen is approaching is very sensitive to other magnetic fields around it, since it must sense the strength of the magnetic force.

However, recently, the personal portable device has been made slim for reasons of convenience and aesthetics of users, and not only the arrangement of the parts to be mounted in the inside becomes dense, but also the parts are miniaturized, so that a magnetic field interference problem may occur.

In particular, a vibration motor is a component that converts electrical energy into mechanical vibration through mutual action of a coil and a magnet. In recent years, a linear vibration motor is generally used instead of a rotary vibration motor which has been used for a long time because of its quick response and long life.

In a linear vibration motor, a vibrator coupled with an elastic body generates vibration while resonating up and down in accordance with the resonance frequency. Since the up-and-down resonance displacement must be secured, a magnet having a relatively strong magnetic force has to be used in order to reduce the thickness. The use of the magnet having such a strong magnetic force has caused a problem that interference between the magnet and the magnetic field of other parts, particularly the stylus pen, occurs.

Therefore, it is urgently required to study vibration motors which are thin in thickness while ensuring a vibration level above a certain level, and magnetic fields do not flow out to the outside.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vibration motor which can reduce a magnetic field flowing outward while being thin.

According to an aspect of the present invention, there is provided a linear motor comprising: a housing defining an inner space of a predetermined size; at least one magnet disposed inside the housing and having a through hole and generating a magnetic force; A vibrator having an oscillator and an elastic member coupled to the inside of the case to provide an elastic force, and an elastic member coupled to the oscillator and configured to transmit an electric signal to the coil, .

Here, the magnet may be formed in a columnar shape, and the through hole may penetrate the upper surface and the lower surface of the magnet.

Further, the filler may be filled in the through-hole.

In addition, the housing may have a through-hole fixing protrusion that engages with the inner circumferential surface of the through-hole.

The magnet may further include a plate coupled with the magnet.

According to the linear motor of the present invention, the outflow of the magnetic field can be minimized while minimizing the thickness.

Further, by maintaining the displacement of the vibrator, an appropriate vibration amount can be maintained.

1 is a sectional view of a linear motor according to an embodiment of the present invention.
2 is an exploded perspective view of a linear motor according to an embodiment of the present invention.
3 is an exploded perspective view of a linear motor according to an embodiment of the present invention.
4 is a perspective view of a portion of a linear motor according to an embodiment of the invention.
5 is a sectional view of a linear motor according to an embodiment of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the underlying concepts of the embodiments described. However, those skilled in the art will recognize that the embodiments described may be practiced without some or all of these specific details. In other instances, well-known components have not been described in detail so as not to unnecessarily obscure the basic concept of the present invention.

The embodiments of the present invention can be modified into various forms and the scope of the present invention should not be interpreted as being limited by the embodiments described below. The present embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes and the like of the components in the drawings are exaggerated in order to emphasize a clearer explanation.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. Respectively.

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

FIG. 1 is a schematic cross-sectional view of a linear motor 600 according to the present invention, and FIG. 2 is a schematic exploded perspective view of a linear motor 600 shown in FIG. 3 is a schematic cutaway perspective view of the linear motor 600 shown in Fig.

1 to 3, the linear motor 600 according to the present invention may include a housing 100, a magnet 200, a vibrator 300, an elastic member 400, and a substrate 500.

The housing 100 may include a case 110 and a bracket 130.

The case 110 may have an internal space of a predetermined size and an open bottom. The opened lower portion of the case 110 may be sealed with the bracket 130 to be described later. The inner space formed by the case 110 is limited by the engagement with the bracket 130.

Typically, the case 110 may have a cylindrical shape with an open bottom. The side wall part of the case 110 may have an opening through which a connecting piece 530 of a substrate, which will be described later, is exposed to the outside.

The bracket 130 may be coupled with the lower surface of the case 110 to define an internal space. Since the bracket 130 is engaged with the lower surface of the case 110, the shape of the bracket 130 may correspond to the opened lower surface of the case 110. Typically, the case 110 is cylindrical with an open bottom, so it may be of the disc type of the bracket 130 in general.

The bracket 130 may be coupled at a position corresponding to the opening of the case 110 and may have a support piece 131 to which the connecting piece 530 may be disposed.

It is also possible that the bracket 130 forms an internal space and the case 110 seals the open side of the bracket 130 to define the internal space. The case 110 and the bracket 130 may be integrally formed.

The magnet 200, the vibrator 300, the elastic member 400, and the substrate 500, which will be described later, may be mounted on the inner space of the housing 100 formed by the case 110 and the bracket 130.

In particular, the magnet 200 may be coupled to the inner surface of the housing 100. 1 to 3, the magnet 200 is coupled to the lower surface of the housing 100, but it is also possible to couple the magnet 200 to the upper surface.

The housing 100 may have a fixing protrusion 150 which can fix and engage the magnet 200 when the magnet 200 is coupled to the inside of the housing 100. The fixing protrusion 150 includes an outer circumferential surface fixing protrusion 151 that engages with at least a portion of the outer circumferential surface of the magnet 200 and a through hole fixing protrusion 151 that engages with at least a portion of the inner circumferential surface of the through hole 210 of the magnet 200 153).

The fixing protrusions 150 may protrude vertically from the housing 100 to the inside of the housing 100.

The outer circumferential surface fixing protrusion 151 has a ring-shaped protruding projection or an annular arcuate portion having an inner diameter corresponding to the outer diameter of the outer circumferential surface of the magnet 200 so as to be able to engage with at least a part of the outer circumferential surface of the magnet 200. [ and may be a projecting projection of an arc shape.

The through-hole fixing protrusion 153 has the same shape as that of the outer circumferential surface fixing protrusion 151, but its outer diameter can correspond to the inner diameter of the through hole 210.

The fixing protrusions 150 can firmly couple the magnet 200 and facilitate the determination of the coupling position of the magnet during the manufacturing process.

FIG. 4 is a perspective view showing the magnet 200 of the linear motor 600 according to the present invention being coupled and the resin 230 being filled.

The magnet 200 is disposed inside the housing 100, has a through hole 210, and can generate magnetic force. The linear motor 600 of the present invention may include at least one magnet 200.

The magnet 200 may be typically formed in a columnar shape. The through hole 210 may penetrate the upper surface and the lower surface of the magnet 200.

Referring to FIG. 4, the filler 230 may be filled in the through hole 210. The filler 230 may be filled in the whole of the through hole 210 or may be filled only in the portion where the through hole 210 and the through hole fixing protrusion 153 are engaged.

The filler 230 may be a resin having an adhesive force. The filler 230 may be a magnetic fluid having magnetic properties, or may be a non-magnetic substance such as an epoxy having no magnetic property.

8 is leakage magnetic force comparison data of the magnet 200 having the through-hole 210. FIG. Referring to FIG. 8, when the through hole 210 having a different diameter is formed in the magnet 200, the leakage magnetic force is reduced by about 70% at the maximum.

The vibrator 300 may include a coil 310 that generates an electromagnetic force in cooperation with the magnet 200 and a weight 330 that vibrates integrally with the coil 310. The vibrator 300 is coupled with the elastic member 400 and is vibrated by receiving an elastic force.

The coil 310 may be formed in a ring shape through which the magnet 200 penetrates in the central portion and the weight 330 may be formed in an annular shape that can be coupled to the outer circumferential surface of the coil 310. The coil 310 and the weight 330 may be coupled through the coupling member 350. Therefore, the inner diameter of the coil 310 may be formed to be larger than the outer diameter of the magnet 200. The inner diameter of the weight 330 may be the same as or slightly larger than the outer diameter of the coil 310. The outer circumferential surface of the weight 330 may be formed smaller than the inner circumferential surface of the housing 100 so that the weight 330 does not come into contact with the housing 100 when vibrating.

The coil 310 may receive an AC electrical signal having a specific frequency from the substrate 500. The coil 310 and the weight 330, which are supplied with an AC electric signal, interact with the magnet 200 to vibrate at a specific natural frequency.

The weight 330 may be a vibrator 300 that vibrates together with the coil 310. The weight 330 can adjust the resonance frequency and adjust the amount of vibration by increasing the mass of the vibrator 300.

The elastic member 400 may be coupled to the inside of the vibrator 300 and the housing 100 to provide an elastic force. One side of the elastic member 400 can be coupled to the inside of the housing 100. The other side of the elastic member 400 can engage with the vibrator 300.

The elastic member 400 may be, for example, a coil spring or a leaf spring, but is not limited thereto.

The substrate 500 is coupled with the vibrator 300 and transmits an electric signal to the coil 310. The substrate 500 is composed of a vibrating piece 510 that vibrates integrally with the vibrator 300 and a connecting piece 530 that extends from the vibrating piece 510 and is connected to the outside.

The vibrating element 510 may be a flexible material or an elastic material so as to be able to oscillate integrally with the vibrator 300. For example, it may be a flexible printed circuit board (FPCB), but is not limited thereto.

One end of the vibrating element 510 is coupled with the vibrator 300 to supply an alternating current electrical signal having a specific frequency to the coil 310. [ The other end of the vibrating element 510 extends to the connecting piece 530.

The connecting piece 530 is disposed on the upper surface of the supporting piece 131 of the bracket 130 and receives an AC electric signal having a specific frequency from the outside. Therefore, a terminal portion that can be connected to the outside may be formed at one end of the connecting piece 530. [

The connecting piece 530 may be formed in a ring shape or an arc shape so as to surround at least a part of the outer circumferential surface of the magnet 200 without being in contact with the magnet 200. [

5 is a cross-sectional view of a linear motor 600 according to an embodiment of the present invention. 6 is an exploded perspective view of a linear motor 600 according to an embodiment of the present invention. 7 is a cross-sectional view of a portion of a linear motor 600 according to an embodiment of the present invention.

5 to 7, the linear motor 600 according to the present invention may further include one plate 251, 253 to be coupled to the magnet 200. The plates 251 and 253 may have an upper plate 251 and a lower plate 253 depending on the position where the magnet 200 is coupled. At least one of the upper plate 251 and the lower plate 253 of the plates 251 and 253 may be coupled to the magnet 200.

The plates 251 and 253 allow the magnetic flux passing through the coil 310 to flow smoothly into the magnet 200. The plates 251 and 253 may be formed of a magnetic material, but are not limited thereto. The plates 251 and 253 and the magnet 200 may be combined using a magnetic fluid, but are not limited thereto.

Even when the plates 251 and 253 are coupled to the magnet 200, the through hole of the magnet 200 can be filled with the filler 230.

When the lower plate 253 is coupled to the lower surface of the magnet 200, the through hole fixing protrusion 153 may not be formed in the housing 100.

The lower plate 253 coupled to the lower surface of the magnet 200 may have a through hole fixing protrusion 153 which is coupled to the inner circumferential surface of the through hole 210 on the upper surface. The through hole fixing protrusion 153 provided in the lower plate 253 is inserted into the through hole 210 of the magnet 200 to fix the magnet 200. The surfaces of the through hole fixing projections 153 and the through holes 210 may be combined by the filler 230.

100: Housing
110: Case 130: Bracket
151: outer circumferential surface fixing protrusion 153: through hole fixing protrusion
200: Magnet
210: Through hole 230: Filler
251: upper plate 253: lower plate
300: oscillator
310: coil 330: weight
400: elastic member
500: substrate
510: Vibrating piece 530: Connecting piece

Claims

A housing defining an internal space of a predetermined size;
At least one magnet disposed inside the housing and having a through hole, the magnet generating magnetic force;
A vibrator having a coil for generating an electromagnetic force in interaction with the magnet and a weight for oscillating as a unit with the coil;
An elastic member coupled to the vibrator and the case to provide an elastic force; And
A substrate coupled to the oscillator and configured to transmit an electrical signal to the coil,
Linear motor.

The method according to claim 1,
The magnet is formed in a columnar shape,
The through-hole passes through the upper surface and the lower surface of the magnet
Linear motor.

The method according to claim 1,
When the filler is filled in the through hole
Linear motor.

The method according to claim 1,
The housing has a through-hole fixing protrusion that engages with an inner circumferential surface of the through-hole
Linear motor.

The method according to claim 1,
Further comprising at least one plate engaging with said magnet
Linear motor.

6. The method of claim 5,
The plate is engaged with the lower surface of the magnet,
And the upper surface of the plate has a through-hole fixing protrusion that engages with the inner circumferential surface of the through-hole
Linear motor.