Linear vibration motor

Abstract

The invention relates to the technical field of exciters, in particular to a linear vibration motor, which comprises a shell, a linear vibration motor, a linear vibration motor and a driving device, the vibration assembly is suspended in the containing cavity and comprises a mass block and an elastic arm, the two sides of the elastic arm are connected with the mass block and the shell respectively, and the vibration assembly further comprises a magnetic circuit structure arranged on the mass block; the coil assembly is fixed in the shell and comprises a first coil and a second coil which are arranged in parallel; the magnetic circuit structure comprises first magnetic steel, second magnetic steel and third magnetic steel, the second magnetic steel and the third magnetic steel are arranged on the two sides of the first magnetic steel, the first coil is arranged in a cavity between the first magnetic steel and the second magnetic steel, and the second coil is arranged in a cavity between the first magnetic steel and the third magnetic steel. The opposite surfaces of the first magnetic steel and the second magnetic steel and the opposite surfaces of the first magnetic steel and the third magnetic steel have the same polarity, and the winding directions of the first coil and the second coil are opposite. Through the arrangement, the magnetic field utilization rate is improved, and the vibration effect of the linear vibration motor is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of exciters, and particularly to a linear vibration motor. Background Art

[0002] A linear vibration motor is an electrical appliance that can generate vibrations in a linear direction. It is widely used in electronic products such as smartphones, touch devices, and game controllers to provide vibration feedback.

[0003] In related technologies, a linear vibration motor generally includes a coil for generating an alternating magnetic field, a permanent magnet capable of providing a fixed magnetic field, a mass block fixedly connected to the permanent magnet, and a shrapnel structure connected between the mass block and the housing; when an electric current passes through the coil, an alternating magnetic field is generated, and the magnetic field generated by the coil interacts with the magnetic field generated by the permanent magnet, causing the mass block to perform reciprocating motion, and then transmitting the vibration to the outside.

[0004] However, the existing linear vibration motor has insufficient power, which affects the vibration effect of the motor. Summary of the Invention

[0005] In view of at least one of the above technical problems, the present invention provides a linear vibration motor, which improves the magnetic field utilization rate by improving the magnetic circuit, thereby improving the vibration effect.

[0006] According to a first aspect of the present invention, there is provided a linear vibration motor, comprising: A housing, the interior of which has a receiving chamber; A vibration assembly, which is suspended in the receiving chamber, includes a mass block and elastic arms respectively connected to the mass block and the housing on both sides, and the vibration assembly further includes a magnetic circuit structure provided on the mass block; A coil assembly, fixed in the housing, includes a first coil and a second coil arranged in parallel; Wherein, the magnetic circuit structure includes a first permanent magnet, and a second permanent magnet and a third permanent magnet arranged on both sides of the first permanent magnet. The first coil is placed in the cavity between the first permanent magnet and the second permanent magnet, the second coil is placed in the cavity between the first permanent magnet and the third permanent magnet, the opposite surfaces of the first permanent magnet and the second permanent magnet and the opposite surfaces of the first permanent magnet and the third permanent magnet have the same polarity, and the winding directions of the first coil and the second coil are opposite.

[0007] Furthermore, the first permanent magnet, the second permanent magnet, and the third permanent magnet are all three-pole permanent magnets, and the adjacent surfaces have opposite polarities. Two magnetic circuits are formed between the first coil and the second permanent magnet, between the first coil and the second coil, and between the second coil and the third permanent magnet.

[0008] Further, the mass block is hollow inside to form a rectangular hollow portion. On both side walls of the hollow portion in the length direction, there are card slots extending towards both ends. Both ends of the first permanent magnet are fixed in the card slots, and the hollow portion is divided into two hollow cavities. The second permanent magnet and the third permanent magnet are respectively fixed on the side walls of the two hollow cavities away from the first permanent magnet.

[0009] Further, magnetic conduction plates are also attached to the sides of the second permanent magnet and the third permanent magnet away from the first permanent magnet.

[0010] Further, the first coil and the second coil are wound around a skeleton, and the skeleton is made of a magnetic conduction material.

[0011] Further, the skeleton is made of iron-nickel alloy or nickel-cobalt alloy.

[0012] Further, the elastic arm includes a first end and a second end arranged in parallel, and further includes a first force arm with one end bent and connected to the first end, and a second force arm with one end bent and connected to the first force arm and the other end connected to the second end. The first end is connected to the mass block, and the second end is connected to the housing.

[0013] Further, the elastic arm further includes a connecting plate fittingly fixed on the upper surface or the lower surface of the mass block. At the edge of the connecting plate, there are connecting arms arranged vertically, and the connecting arms are connected to the first end.

[0014] Further, the elastic arm and the connecting plate are integrally formed.

[0015] Further, two elastic arms are symmetrically arranged in the thickness direction at the same end of the mass block.

[0016] The beneficial effects of the present invention are as follows: Through the same polarities of the permanent magnets on the opposite surfaces in the magnetic circuit structure and the setting of the first coil and the second coil with opposite winding directions in the magnetic circuit structure, the utilization rate of the magnetic field of the magnetic circuit is higher, and a stronger driving force can be provided, thereby improving the vibration effect of the linear vibration motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic structural diagram of the linear vibration motor in the embodiment of the present invention; Figure 2 Schematic diagram of the magnetic circuit structure and the coil assembly in the embodiment of the present invention; Figure 3 Schematic diagram of the magnetic circuit in the embodiment of the present invention; Figure 4 Schematic diagram of the winding direction structure of the coil assembly in the embodiment of the present invention; Figure 5 Schematic diagram of the connection structure between the mass block and the magnetic circuit structure in the embodiment of the present invention; Figure 6 Schematic diagram of the structure of a conventional spring arm in the prior art; Figure 7 Schematic diagram of the structure of the spring arm in the embodiment of the present invention; Figure 8 Schematic diagram of a structural deformation of the spring arm in the embodiment of the present invention; Figure 9 Schematic diagram of the structural arrangement of another spring arm in the embodiment of the present invention.

[0019] Explanation of reference numerals: 1. Outer shell; 2. Vibration assembly; 21. Mass block; 211. Hollow part; 211a. Card slot; 22. Spring arm; 221. First end; 222. Second end; 223. First force arm; 224. Second force arm; 225. Connection plate; 226. Connection arm; 23. Magnetic circuit structure; 231. First magnet; 232. Second magnet; 233. Third magnet; 234. Magnetic conduction plate; 3. Coil assembly; 31. First coil; 32. Second coil; 33. Skeleton. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] As Figures 1 to 9 shown, the linear vibration motor includes a housing 1, a vibration assembly 2 and a coil assembly 3, specifically as Figure 1 shown in, the interior of the housing 1 has a receiving chamber. In some embodiments of the present invention, the housing 1 can be composed of a bottom plate and an upper shell, or can be integrally formed by bending sheet metal. The receiving chamber inside it is used to fix the coil assembly 3 and the vibration assembly 2.

[0024] Please continue to refer to Figure 1 , in the embodiments of the present invention, the vibration assembly 2 is suspended in the receiving chamber and includes a mass block 21 and spring arms 22 respectively connected to the mass block 21 and the housing 1 on both sides. The vibration assembly 2 further includes a magnetic circuit structure 23 provided on the mass block 21; in some embodiments of the present invention, one end of the spring arm 22 is connected to the housing 1 and the other end is connected to the mass block 21, so that the mass block 21 is suspended in the receiving chamber. In the embodiments of the present invention, the spring arms 22 are provided on both sides in the length direction of the mass block 21, so that the mass block 21 vibrates along the Figure 1 X-axis direction as shown in.

[0025] In the embodiments of the present invention, the coil assembly 3 is fixed inside the housing 1 and includes a first coil 31 and a second coil 32 arranged in parallel. The first coil 31 and the second coil 32 can be electrically connected by means of an FPC flexible circuit board. The specific driving method of the coil alternating current is the prior art and will not be elaborated here.

[0026] Please continue to refer to Figure 2 , in the embodiments of the present invention, the magnetic circuit structure 23 includes a first magnet 231 and second magnets 232 and 233 provided on both sides of the first magnet 231. The first coil 31 is placed in the cavity between the first magnet 231 and the second magnet 232, and the second coil 32 is placed in the cavity between the first magnet 231 and the third magnet 233. The opposite faces of the first magnet 231 and the second magnet 232 and the opposite faces of the first magnet 231 and the third magnet 233 have the same polarity, and the winding directions of the first coil 31 and the second coil 32 are opposite. By setting the same polarity of the opposite faces of the first magnet 231 and the second magnet 232, the magnetic field lines between them repel each other, so that after the coil is energized, the magnetic fields generated in the directions towards the first magnet 231 side and the second magnet 232 side can both be subjected to force. Similarly, asFigure 4 As shown, by setting the winding directions of the second coil 32 to be opposite, the magnetic fields generated in the directions of the second coil 32 towards the first magnet 231 side and the third magnet 233 side are both subjected to force; compared with the prior art, the utilization rate of the magnetic field is higher, and thus more sufficient power can be provided.

[0027] In the above embodiment, by setting the polarities of the opposite-facing magnets in the magnetic circuit structure 23 to be the same and setting the first coil 31 and the second coil 32 with opposite winding directions in the magnetic circuit structure 23, the utilization rate of the magnetic field of the magnetic circuit is higher, a stronger driving force can be provided, and thus the vibration effect of the linear vibration motor is improved.

[0028] Based on the above embodiment, as Figure 3 shown, the first magnet 231, the second magnet 232, and the third magnet 233 are all three-pole magnets, and the polarities of adjacent faces are opposite. Specifically, please refer to Figure 3 , taking the first magnet 231 as an example, the polarities of its middle and both ends are opposite, and the polarities of its upper and lower faces are also opposite. Through the setting of this structural form, two magnetic circuits are formed between the first coil 31 and the second magnet 232, between the first coil 31 and the second coil 32, and between the second coil 32 and the third magnet 233. Through the setting of the three-pole magnet, 6 magnetic circuits as shown in Figure 3 are formed between the magnet and the coil, thereby further improving the utilization rate of the magnetic field.

[0029] In the embodiment of the present invention, as Figure 5 shown, the mass block 21 is provided with a hollow interior, forming a rectangular hollow portion 211. Card slots 211a extending towards both ends are opened on the two side walls of the hollow portion 211 in the length direction. Both ends of the first magnet 231 are fixed in the card slots 211a, and the hollow portion 211 is divided into two hollow cavities. The second magnet 232 and the third magnet 233 are respectively fixed on the side walls of the two hollow cavities away from the first magnet 231. When specifically fixing the first magnet 231, it can be achieved by means of bonding, or a snap structure can be provided at the card slots 211a. Through the setting of the card slots 211a, it is convenient to position and fix the first magnet 231.

[0030] In order to reduce the magnetic circuit waste of the second magnet 232 and the third magnet 233, in the embodiment of the present invention, please continue to refer to Figure 5, on the side of the second magnet 232 and the third magnet 233 away from the first magnet 231, a magnetic conductive plate 234 is also attached. Through the setting of the magnetic conductive plate 234, the magnetic induction lines are mostly transmitted through the magnetic conductive plate 234, thereby reducing the waste of the magnetic field; at the same time, the way of fixing the second magnet 232 and the third magnet 233 on the side wall of the hollow part 211 of the mass block 21 also facilitates the fixing of the magnets.

[0031] As Figure 4 shown in, in an embodiment of the present invention, the first coil 31 and the second coil 32 are wound around a bobbin 33, and the bobbin 33 is a magnetic conductive material. Specifically, in some embodiments of the present invention, the bobbin 33 is an iron-nickel alloy or a nickel-cobalt alloy. When the bobbin 33 is specifically processed, the process of injection powder metallurgy can be used to complete. Through the setting of the bobbin 33, the magnetic circuit of the coil is stronger to improve the driving force of the mass block 21.

[0032] In an embodiment of the present invention, the structure of the elastic arm 22 is also improved. As Figure 6 shown in is a traditional C-shaped elastic sheet. During the movement of the traditional elastic sheet, the force arm rotates around the fulcrum. In addition to the movement stroke in the X direction as Figure 6 shown in, there is also a certain degree of movement stroke in the Y direction; as Figure 6 shown in, y1 is the moving distance along the Y direction. This kind of moving distance will cause the magnets and the coils to approach each other. The traditional solution is to increase the gap between the coils and the magnets, but this way also reduces the interaction between the coils and the magnets, thereby reducing the driving force. In an embodiment of the present invention, as Figure 7 shown in, the elastic arm 22 includes a first end 221 and a second end 222 arranged in parallel, and further includes a first force arm 223 whose one end is bent and connected to the first end 221, and a second force arm 224 whose one end is bent and connected to the first force arm 223 and the other end is connected to the second end 222. The first end 221 is connected to the mass block 21, and the second end 222 is connected to the housing 1. In this way, through the increase of the force arms, the first force arm 223 mainly moves along the fulcrum between it and the second force arm 224, and the second force arm 224 mainly moves along the fulcrum at the connection with the second end 222. In this way, the length of the first force arm 223 is less than that of the traditional force arm, so its displacement in the y direction is reduced, and the movement directions of the first force arm 223 and the second force arm 224 in the y direction are opposite, and thus the total stroke of the first force arm 223 and the second force arm 224 in the y direction is much less than that of the traditional force arm. Through such a structure setting of the elastic arm 22, the magnetic gap can be further reduced and the magnetic force can be enhanced.

[0033] In some embodiments of the present invention, as Figure 8As shown in the figure, the spring arm 22 further includes a connecting plate 225 that is fitted and fixed to the upper or lower surface of the mass 21. At the edge of the connecting plate 225, there is a connecting arm 226 arranged vertically, and the connecting arm 226 is connected to the first end 221. Through the setting of the connecting plate 225, on the one hand, the installation difficulty is reduced. On the other hand, since the connecting arm 226 is perpendicular to the connecting plate 225, after the connecting plate 225 is fixed to the mass 21, the connection between the first end 221 of the spring arm 22 and the mass 21 is eliminated, thus simplifying the installation steps and improving the positioning accuracy. In the embodiment of the present invention, the spring arm 22 and the connecting plate 225 are integrally formed. Specifically, it can be achieved by the process of sheet metal bending. Regarding the fixation of the connecting plate 225 to the mass 21, a positioning structure can be provided on the connecting plate 225, and then it can be fixed by bonding or welding.

[0034] In some other embodiments of the present invention, the arrangement mode of the spring arm 22 is also improved, such as Figure 9 As shown in the figure, two spring arms 22 are symmetrically arranged in the thickness direction at the same end of the mass 21. That is, the first ends 221 of the spring arms 22 are respectively fixed on both sides in the width direction of the mass 21, and the second ends 222 of the two spring arms 22 are connected to the housing. In this way, through the setting of the structure form of the four spring arms 22, when the mass 21 is moving, the left spring arm 22 pulls outwards, and the right spring arm 22 contracts inwards. The overall force on the mass 21 is symmetrical, and this movement path is a strictly horizontal movement. In addition, the spring arm 22 can also reduce the stiffness in the direction perpendicular to the movement direction, thereby further reducing the phenomenon of stress concentration.

[0035] Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A linear vibration motor, characterized in that, Comprising: A housing, the interior of which has a receiving chamber; A vibration assembly, which is suspended in the receiving chamber, includes a mass block and elastic arms respectively connected to the mass block and the housing on both sides, and the vibration assembly further includes a magnetic circuit structure arranged on the mass block; A coil assembly, fixed in the housing, includes a first coil and a second coil arranged in parallel; Wherein, the magnetic circuit structure includes a first magnet and second and third magnets arranged on both sides of the first magnet. The first coil is placed in the cavity between the first magnet and the second magnet, and the second coil is placed in the cavity between the first magnet and the third magnet. The surfaces of the first magnet opposite to the second magnet and the first magnet opposite to the third magnet have the same polarity, and the winding directions of the first coil and the second coil are opposite.

2. The linear vibration motor according to claim 1, characterized in that The first magnet, the second magnet and the third magnet are all three-pole magnets, and the adjacent surfaces have opposite polarities. Two magnetic circuits are formed between the first coil and the second magnet, between the first coil and the second coil, and between the second coil and the third magnet.

3. The linear vibration motor according to claim 1, characterized in that The mass block is hollowly arranged to form a rectangular hollow part. Slots extending towards both ends are opened on the two side walls of the hollow part in the length direction. Both ends of the first magnet are fixed in the slots, and the hollow part is separated into two hollow cavities. The second magnet and the third magnet are respectively fixed on the side walls of the two hollow cavities away from the first magnet.

4. The linear vibration motor according to claim 3, characterized in that The second magnet and the third magnet are also attached with magnetic conductive plates on the sides away from the first magnet.

5. The linear vibration motor according to claim 1, characterized in that The first coil and the second coil are wound on a skeleton, and the skeleton is made of a magnetic conductive material.

6. The linear vibration motor according to claim 5, characterized in that The skeleton is made of iron-nickel alloy or nickel-cobalt alloy.

7. The linear vibration motor according to claim 1, characterized in that The elastic arm includes a first end and a second end arranged in parallel, and further includes a first force arm with one end bent and connected to the first end, and a second force arm with one end bent and connected to the first force arm and the other end connected to the second end. The first end is connected to the mass block, and the second end is connected to the housing.

8. The linear vibration motor according to claim 7, characterized in that The elastic arm further includes a connecting plate attached and fixed to the upper surface or the lower surface of the mass block. The edge of the connecting plate has a connecting arm arranged vertically, and the connecting arm is connected to the first end.

9. The linear vibration motor according to claim 8, characterized in that The elastic arm and the connecting plate are integrally formed.

10. The linear vibration motor according to claim 7, characterized in that Two elastic arms are symmetrically arranged in the thickness direction at the same end of the mass block.

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