Short-axis direction horizontal linear vibration actuator

Abstract

The present invention relates to a short-axis direction horizontal linear vibration actuator, and more particularly, to a short-axis direction horizontal linear vibration actuator that effectively controls a strong vibration force by concentrating a geomagnetic field, thereby minimizing driving noise. Accordingly, as the market for virtual reality (VR) and augmented reality (AR) expands beyond the mobile phone market, the short-axis direction horizontal linear vibration actuator can be applied to various goods such as car electronics, home appliances, and beauty products.

Description

TECHNICAL FIELD

[0001] The present invention relates to a short-axis direction horizontal linear vibration actuator, and more particularly, to a short-axis direction horizontal linear vibration actuator that effectively controls a strong vibration force by concentrating a geomagnetic field, thereby minimizing driving noise, and that can be applied to various goods such as automotive electronics, home appliances, and beauty products, as the market for virtual reality (VR) and augmented reality (AR) expands beyond the mobile phone market. BACKGROUND

[0002] The initial model of a vibration actuator mounted in a communication instrument for portability has a rotational vibration motor form having a stator and a rotor as basic structures. This rotational vibration motor fixes a shaft portion on a support of the stator, and makes the rotor rotate on the shaft portion to generate vibration. In order to increase the vibration force, the volume of the rotor is increased, or the number of rotations is increased to improve the vibration force. However, there are limitations in miniaturization and great difficulties in generating high vibration due to structural problems, and it is difficult to secure a lifespan of a predetermined time or more.

[0003] In order to improve the problems of the rotational vibration motor, a horizontal vibration actuator type vibration motor has recently been disclosed.

[0004] The disclosed horizontal vibration actuator type vibration motor includes an upper case portion and a lower case portion combined with each other, a magnetic force generating means formed on at least one surface of the upper case portion and the lower case portion, a magnet subjected to an attractive force or a repulsive force from the magnetic force generating means, a weight portion in which the magnet is installed to be integrated with the magnet and which moves up and down to increase the vibration force, an elastic means elastically supporting the weight portion on a lower portion of any one of the upper surface and the lower surface of the weight portion, and a fixing member for fixing the other end of the elastic means to the upper case portion and the lower case portion.

[0005] This horizontal vibration actuator type vibration motor can extend the lifespan, overcome the limit of size, and obtain a fast response speed compared to the rotational vibration motor, and thus has recently been widely used. However, when the up-and-down vibration actuator is mounted on a product to be driven, although the vibration transmission ability is excellent, the up-and-down vibration can generate resonance, and there is a problem in that the driving noise is large. In order to improve this resonance noise, many horizontal vibration actuators have recently been developed, but as the size of the instrument using the actuator increases, there is a problem in that it is difficult to express various haptic feedback vibration effects.

[0006] In addition, most of the horizontal vibration actuators form a vibration direction in a long-axis direction, and it is difficult to be mounted on a product requiring vibration in a short-axis direction.

[0007] Further, a strong vibration force can cause greater driving noise.

[0008] Therefore, there is a need to develop a vibration actuator that can improve the above problems.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] (Patent Document 1) Korean Patent Publication No. 10-2010-0073301 (2010.07.01.) SUMMARY

[0012] Technical Problem to be Solved

[0013] The present invention has been made to solve the problems of the prior art, and aims to provide a short-axis direction horizontal linear vibration actuator that can vibrate in a short-axis direction, thereby improving the problem that horizontal vibration motors mostly vibrate in a long-axis direction, thereby making it difficult to install the horizontal vibration motors in products that need to vibrate in a short-axis direction.

[0014] Further, the present invention aims to provide a short-axis direction horizontal linear vibration actuator that has a strong vibration force and can improve a vibration response time by minimizing a magnetic flux leakage to the outside and maximizing a magnetic field efficiency.

[0015] Further, the present invention aims to provide a short-axis direction horizontal linear vibration actuator that can effectively control a strong vibration force by concentrating an electromagnetic field and minimize driving noise.

[0016] Technical Solution

[0017] To achieve the above object, the present invention provides a short-axis direction horizontal linear vibration actuator, including: a bracket 10 that is a housing formed to fix and support a flexible printed circuit board 20, a spring 60, and a coil 90; a yoke plate 110 that fixes an upper magnet 100 and a weight part 120, and is combined with a yoke part 40 to form a closed loop of a magnetic field generated in the upper magnet 100, thereby shielding a magnetic flux leakage; and the weight part 120 that is fixed to the yoke plate 110, amplifies vibration using the weight of the weight part, and determines a resonance frequency.

[0018] The yoke plate 110 includes a yoke plate body 111, a magnetic field concentrated portion of the upper surface of the yoke plate body 111 is formed by a concave groove 113 in a forged form, for coating and fixing a magnetic fluid 130, the magnetic fluid 130 is disposed at the upper surface of the yoke plate body 111 at the support groove 113; the upper surface of the weight portion 120 forms a weight portion protrusion 122 protruding higher than the upper surface of the yoke plate body 111; the upper surface of the yoke plate body 111 coated with the magnetic fluid 130 forms a certain space.

[0019] Further, the bracket 10 and the spring 60 and the first support portion 70 and the second support portion 80 disposed at both ends of the spring are respectively provided with shock absorbers 150 in diagonal directions.

[0020] Further, the magnetic fluid 130 is a colloidal liquid form of iron oxide with a particle diameter of 10.0 nm mixed with base oil and surfactant.

[0021] Inventive Effects

[0022] The present application can be applied to products that are limited in installation due to vibration in the long axis direction, and can expand the range of applicable products by improving the vibration direction to the short axis direction.

[0023] In addition, the present application locates the coil at the center and sets the magnets up and down to form a closed magnetic field loop, improve the electromagnetic field force, and maximize the vibration force to further improve the vibration response time.

[0024] In addition, the present application uses the characteristics of magnetic fluid (Magnetic Fluid) that is magnetized by the influence of a magnet, fixes it at a specified position, uses the shock absorbing effect of the soft liquid component, can effectively control the vibration force, and can improve the noise. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a cross-sectional view of a short axis direction horizontal linear vibration actuator of the present application.

[0026] Figure 2 is an exploded perspective view of a short axis direction horizontal linear vibration actuator of the present application.

[0027] Figure 3 is a longitudinal cross-sectional view of a short axis direction horizontal linear vibration actuator of the present application.

[0028] Figure 4 is a plan view of a short axis direction horizontal linear vibration actuator of the present application and a diagram showing the magnetic field distribution and leakage flux thereof.

[0029] Figure 5FIG. 1 is a plan view of a linear vibration actuator of the prior art, and FIG. 2 is a diagram showing a magnetic field distribution and a leakage magnetic flux of the linear vibration actuator of the prior art.

[0030] Figure 6 FIG. 3 is a graph showing a vibration force characteristic of a short-axis direction horizontal linear vibration actuator of the present application, and FIG. 4 is a comparative graph of the vibration force characteristic of the short-axis direction horizontal linear vibration actuator of the present application and that of the prior art.

[0031] Figure 7 FIG. 5 is a plan view of another embodiment of the short-axis direction horizontal linear vibration actuator of the present application.

[0032] REFERENCE NUMERALS

[0033] 10: holder 20: flexible printed circuit board

[0034] 30: insulating tape 40: yoke portion

[0035] 50: lower magnet 60: spring

[0036] 70: first support portion 80: second support portion

[0037] 90: coil 100: upper magnet

[0038] 110: yoke plate 120: weight portion

[0039] 122: weight portion protrusion 130: magnetic fluid

[0040] 140: box portion DETAILED DESCRIPTION

[0041] Hereinafter, the present application can be variously changed, and can have various embodiments, and a specific embodiment will be described in detail with reference to the accompanying drawings. However, the present application is not limited to only the specific embodiment, and it should be understood that the present application includes all changes, equivalents, and substitutions having the idea and technical scope of the present application.

[0042] In order for those skilled in the art to more clearly understand the present application, embodiments of the present application are provided. Therefore, the shapes of the respective elements shown in the accompanying drawings can be exaggerated for a clearer explanation, and when the present application is explained, detailed explanations of related known technologies will be omitted if it is considered that the detailed explanations will confuse the gist of the present application.

[0043] The terms of first, second, and the like can be used when explaining various constituent elements, but the constituent elements are not limited to the terms. The terms are used only to distinguish one constituent element from other constituent elements.

[0044] The terms used in the present application are used only to explain specific embodiments and are not intended to limit the present application. The singular expression includes the plural meaning unless it is explicitly stated to the contrary.

[0045] The terms such as "include" or "have" used in the present application are used to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described in the specification, and are understood to not preclude the presence or addition of one or more other features, numbers, steps, actions, components, parts or combinations thereof.

[0046] First, the present application relates to a short-axis direction horizontal linear vibration actuator, which is composed of at least any one or more of a bracket 10, a flexible printed circuit board 20, an insulating tape 30, a yoke portion 40, a lower magnet 50, a spring 60, a first support portion 70, a second support portion 80, a coil 90, an upper magnet 100, a yoke plate 110, a weight portion 120, a magnetic fluid 130 and a box portion 140.

[0047] Hereinafter, preferred embodiments of the present application will be described in more detail with reference to the accompanying drawings.

[0048] Referring to Figures 1 to 3 , Figure 1 is a cross-sectional view of a short-axis direction horizontal linear vibration actuator of the present application; Figure 2 is an exploded perspective view of a short-axis direction horizontal linear vibration actuator of the present application; Figure 3 is a longitudinal cross-sectional view of a short-axis direction horizontal linear vibration actuator of the present application.

[0049] According to the short-axis direction horizontal linear vibration actuator of the present application, a flexible printed circuit board 20 for supplying an external electric signal to a coil 90 is provided on a bracket 10 having a housing, and an insulating tape 30 is attached to a coil attachment surface of the bracket 10, thereby preventing insulation between the bracket 10 and the coil 90.

[0050] Further, a yoke portion 40 is provided to form a closed loop of a magnetic field generated by a lower magnet 50, thereby shielding a leakage magnetic flux, and the yoke portion 40 is fixed to a spring 60, a lower magnet 50 and a yoke plate 110.

[0051] The lower magnet 50 is fixed to the yoke portion 40 by a permanent magnet, thereby generating a magnetic field, and the magnetic field acts with a magnetic field of the coil 90, so that a vibration body generates horizontal vibration.

[0052] Further, the spring 60 is connected to the bracket 10 and the yoke 40 to amplify the vibration and determine the resonance frequency, and a first support part 70 is provided to be fixed to the spring 60 and fixed to the yoke 40 to support the spring 60, thereby preventing deformation and breakage of the spring.

[0053] Further, a coil 90 is provided to generate a magnetic field by an external electric signal and interact with the magnetic field of the magnet to generate vibration, and an upper magnet 100 is provided to be fixed to the yoke plate 110 by a permanent magnet to generate a magnetic field and interact with the magnetic field of the coil 90, thereby allowing the vibration body to generate horizontal vibration.

[0054] The yoke plate 110 fixes the upper magnet 100 and the weight part 120 and combines with the yoke 40 to form a closed loop of the magnetic field generated by the upper magnet 100, thereby shielding the magnetic flux leakage, and the yoke plate 110 has the weight part 120 combined therewith to amplify the vibration by the weight of the weight part and determine the resonance frequency.

[0055] The upper surface of the yoke plate 110 is in contact with the case part 140 and provided with a magnetic fluid 130 to control the vibration force and improve the response speed and noise, and the case part 140 is further provided to form an outer shell to protect the vibration body and shield the magnetic flux leakage.

[0056] Here, the magnetic fluid 130 is a colloidal liquid form of iron oxide having a particle diameter of 10.0 nm mixed with base oil and a surfactant, which does not deteriorate even after a long time, and is a simple liquid without magnetism when the magnetic field is 0, but is magnetized by the magnetic field of a magnet or the like from the outside.

[0057] The yoke plate 110 includes a yoke plate body 111, and a portion of the upper surface of the yoke plate body 111 where the magnetic field is concentrated is formed with a support groove (113) in a forged form by engraving, and in order to more effectively use such a magnetic fluid 130, the magnetic fluid 130 is coated and fixed in the support groove 113 on the portion of the upper surface of the yoke plate body 111 where the magnetic field is concentrated, as shown in the enlarged view of the left upper portion of Figure 3 As shown in the enlarged view of the left upper portion of

[0058] Further, as shown in the enlarged view of the left upper portion of Figure 3As shown in the enlarged view of the right upper portion, in order to fix the magnetic fluid 130 and prevent it from being lost, a support groove 113 in the shape of forging is formed in the center of the main body 111 of the yoke plate 110 by engraving, and the step of the support groove 113 is formed by "WxD", and the magnetic fluid 130 is coated in the support groove 113 in the center of the main body 111 of the yoke plate 110 with a width of "W" and a depth of "D", so that the magnetic field concentration effect can be further improved, and when the magnetic fluid 130 is coated, the shape of the magnetic fluid 130 can be more easily formed.

[0059] In addition, when the yoke plate 110 directly collides with the box portion due to external impact, in order to prevent the scattering and loss of the magnetic fluid 130 due to extrusion, a structure is provided which is higher than the yoke plate 110 by "T", so that the scattering and loss of the magnetic fluid 130 are prevented by forming a space.

[0060] Referring to Figure 4 , Figure 4 is a plan view of a short-axis direction horizontal linear vibration actuator of the present application and a diagram showing the magnetic field distribution and leakage magnetic flux thereof.

[0061] The magnetic fluid 130 provided on the upper portion of the yoke plate 110 according to the present application is provided in the center of the yoke plate 110 where the magnetic field is concentrated by the magnetization characteristics, so that the loss of the magnetic fluid 130 is prevented, and the vibration force and driving noise can be effectively improved by the soft damping effect of the magnetic fluid 130. At this time, the leakage magnetic flux of the short-axis direction horizontal linear vibration actuator of the present application is 0.006 [Tesla], and it can be seen that most of the leakage magnetic flux is shielded.

[0062] Figure 5 is a plan view of a linear vibration actuator of the prior art and a diagram showing the magnetic field distribution and leakage magnetic flux thereof.

[0063] With respect to the short-axis direction horizontal linear vibration actuator of the present application, as shown in Figure 5 , the existing linear vibration actuator has an assembly groove portion provided on the yoke plate assembled with the yoke portion, and it can be seen that a part of the magnetic flux leaks through the gap of the corner portion of the assembly groove portion. At this time, as shown in the magnetic field distribution diagram and the leakage magnetic flux diagram, it can be confirmed that the magnetic flux leaked through the gap of the assembly is about 1,514 [Tesla].

[0064] Figure 6 is a vibration force characteristic graph of the short-axis direction horizontal linear vibration actuator of the present application and a comparison diagram with the existing actuator.

[0065] The short-axis direction horizontal linear vibration actuator of the present application can improve the driving noise by easily controlling the vibration force, and it can be seen that, compared to the existing vibration in which a slight waveform distortion is generated at a certain period, the present application does not generate a slight waveform distortion, and can obtain a vibration with a more stable period.

[0066] Figure 7 A plan view of another embodiment of the short-axis direction horizontal linear vibration actuator of the present application.

[0067] The short-axis direction horizontal linear vibration actuator of the present application, the holder 10, the spring 60, and the first support portion 70 and the second support portion 80 are constituted by a simple combination, and in addition to this form, as shown in Figure 7 the holder 10, the spring 60, and the first support portion 70 and the second support portion 80 are respectively provided with a damper in a diagonal direction. In this case, the vibration force can be more easily controlled, and thus the driving noise can be improved.

[0068] The present application has been described above based on the drawings, but this is merely an example, and various substitutions, modifications, and changes can be made within the scope of the technical idea of the present application, and are not limited to the foregoing embodiments and the drawings.

Claims

1. A horizontal linear vibration actuator in the short axis direction, comprising: A bracket (10), which is a shell, is fixed and supports a flexible printed circuit board (20), a spring (60), and a coil (90); a yoke plate (110), which fixes the upper magnet (100) and the weight part (120), and is combined with the yoke part (40) to form a closed loop of the magnetic field generated in the upper magnet (100), thereby shielding the leakage magnetic flux; the weight part (120), which is fixed to the yoke plate (110), uses the weight of the weight part to amplify the vibration and determine the resonant frequency, characterized in that: The yoke plate (110) includes a yoke plate body (111). The magnetic field concentration portion on the upper part of the yoke plate body (111) is formed by engraving a forged support groove (113) for coating and fixing magnetic fluid (130). The magnetic fluid (130) is disposed at the support groove (113) on the upper part of the yoke plate body (111). A weight portion protrusion (122) is formed on the upper part of the weight portion (120) that protrudes from the upper part of the yoke plate body (111). A certain space is formed on the upper part of the yoke plate body (111) coated with magnetic fluid (130). One end of the spring is provided with a first support part (70), which is fixed to the spring (60) and fixed to the yoke part (40) to support the spring (60); the other end of the spring is provided with a second support part (80), which is fixed to the spring (60) and fixed to the bracket (10) to support the spring (60). A shock absorber (150) is provided between the bracket (10) and the spring (60); a shock absorber (150) is provided between the first support portion (70) at one end of the bracket (10) and the spring (60); a shock absorber (150) is provided between the yoke portion (40) and the second support portion (80) at the other end of the spring (60); the shock absorber (150) between the first support portion (70) at one end of the bracket (10) and the spring (60) is arranged diagonally with the shock absorber (150) between the yoke portion (40) and the second support portion (80) at the other end of the spring (60); The magnetic fluid (130) is a colloidal liquid formed by mixing iron oxide with a particle diameter of 10.0 nm with base oil and surfactant.

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