High-stability spring structure for thin linear vibration motor

Abstract

The invention relates to the technical field of motor springs, and particularly discloses a high-stability spring structure for a thin linear vibration motor, which comprises a spring substrate, and Y-shaped elastic units are symmetrically arranged on two sides of the spring substrate; the Y-shaped elastic unit comprises a first shaft piece, a connecting piece, a second shaft piece and a welding piece. The two ends of the first shaft piece are connected with the spring base piece and the connecting piece respectively, the two ends of the second shaft piece are connected with the connecting piece and the welding piece respectively, and the whole spring adopts a double-Y-shaped elastic unit folding mode to form a composite system of an elastic main chain and a stress branch chain with the L-shaped stress release groove. The method comprises the following steps of: carrying out cold hardening and four-section bending on an ultra-thin section to realize'high strength and high precision ', ultrathin material thinning, compact structure and stress space collaborative optimization, and meanwhile, through the design of four-section bending and an L-shaped stress groove, realizing three-stage stress gradient distribution within a free height of 1.2 mm, and improving the proportion of an effective stress region.

Description

Technical Field

[0001] This invention relates to the field of motor spring technology, and more specifically to a high-stability spring structure for thin linear vibration motors. Background Technology

[0002] Miniature vibration motors are indispensable components in industries such as electronics, automobiles, and home appliances, providing users with tactile feedback and vibration alerts. Linear motors are suitable for high-speed linear motion due to their simple structure; and the spring structure, as a component of a linear motor, is a crucial element.

[0003] Current vibration motor spring technology faces the impossible triangle of "thinning - high strength - long life":

[0004] ①The thickness limit of helical springs is limited by their three-dimensional structure;

[0005] ② The lateral dimension of a planar spring and stress concentration create a design paradox;

[0006] ③ Springback control and fatigue life are mutually restrictive in the processing of ultra-thin materials;

[0007] This technological bottleneck directly leads to:

[0008] The thickness of vibration modules in smart wearable devices has long been stuck in the 1.2-1.5mm range;

[0009] Haptic feedback latency >10ms (industry-leading standard requires ≤5ms);

[0010] Spring failures accounted for 32% of the product return rate. Summary of the Invention

[0011] The purpose of this invention is to provide a highly stable spring structure for a thin linear vibration motor to solve the problems mentioned above.

[0012] The objective of this invention can be achieved through the following technical solutions:

[0013] A high-stability spring structure for a thin linear vibration motor includes a spring substrate, on both sides of which Y-shaped elastic units are symmetrically arranged.

[0014] The Y-shaped elastic unit includes a first shaft piece, a connecting piece, a second shaft piece, and a welding piece;

[0015] The two ends of the first shaft piece are connected to the spring base piece and the connecting piece, respectively, and the two ends of the second shaft piece are connected to the connecting piece and the welding piece, respectively.

[0016] As a further aspect of the present invention: an L-shaped stress groove is formed on the side of the connecting piece between the first shaft piece and the second shaft piece.

[0017] As a further aspect of the present invention: the spring substrate and the first shaft are connected by a bending zone, wherein the bending angle of the bending zone is 35°.

[0018] As a further aspect of the present invention: the first shaft piece and the connecting piece are connected by a second bending zone, wherein the bending angle of the second bending zone is 35°.

[0019] As a further aspect of the present invention, the bending direction of the second bending zone is opposite to that of the first bending zone.

[0020] As a further aspect of the present invention: the connecting piece and the second shaft piece are connected by a three-bending zone, wherein the bending angle of the three-bending zone is 30°.

[0021] As a further aspect of the present invention: the second shaft piece and the welding piece are connected by a four-fold bending zone, wherein the bending angle of the four-fold bending zone is 30°.

[0022] As a further aspect of the present invention, the bending direction of the fourth bending zone is opposite to that of the third bending zone.

[0023] As a further aspect of the present invention, the bending direction of the third bending zone is opposite to that of the second bending zone.

[0024] As a further aspect of the present invention: the bending zone three and the bending zone two are located on the same side of the connecting piece.

[0025] The beneficial effects of this invention are:

[0026] (1) In this invention, the spring as a whole adopts the folding method of double Y-shaped elastic unit and L-shaped stress relief groove to form a composite system of "elastic main chain plus stress branch chain". Then, the ultra-thin material is cold-worked and four-segment bending to achieve the unity of "high strength and high precision". Then, the stiffness formula is reverse-designed to match the mainstream motor parameters (mover mass 2-5g).

[0027] (2) In this scheme, the material thickness of the spring is 0.1mm, which achieves the material thinning and the weight of a single piece is only 18mg. The structure is compact, with a free height of 1.2mm. While maintaining the vibration stroke of 0.4mm, the axial space is compressed by 40%, achieving stress space synergistic optimization. At the same time, through the four-segment bending plus L-shaped stress groove design, a three-level stress gradient distribution is achieved within the 1.2mm free height, and the effective stress area ratio is increased to 82%, while the traditional folding structure is only 60%. The 30° stepped bending plus R0.5 rounded corner disperses the maximum stress to below 480MPa. Attached Figure Description

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] Figure 1This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a front view schematic diagram of the overall structure of the present invention;

[0031] Figure 3 This is a side view of the overall structure of the present invention.

[0032] In the diagram: 1. Spring base plate; 2. Y-shaped elastic unit; 21. Bending zone 1; 22. First shaft plate; 23. Bending zone 2; 24. Connecting plate; 25. Bending zone 3; 26. Second shaft plate; 27. Bending zone 4; 28. Welding plate; 3. L-shaped stress groove. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figures 1-3 As shown, the present invention is a high-stability spring structure for a thin linear vibration motor, comprising a spring substrate 1, with Y-shaped elastic units 2 symmetrically arranged on both sides of the spring substrate 1; through symmetrical folding design and precise stress control, it achieves a thickness of 0.1mm, wherein the axial stiffness is 150N / m±5%, the lateral offset resistance is greater than 8:1, the service life is greater than 10 million cycles, and the overall thickness is less than 0.5mm;

[0035] The Y-type elastic unit 2 includes a first shaft piece 22, a connecting piece 24, a second shaft piece 26, and a welding piece 28; the side of the connecting piece 24 is provided with an L-shaped stress groove 3 between the first shaft piece 22 and the second shaft piece 26, that is, the spring is an integral structure, and the L-shaped stress groove 3 is formed by stamping.

[0036] The double Y-shaped symmetrical structure forms two sets of mirror-symmetrical Y-shaped elastic units 2. The axial expansion is eliminated by the 7.6×1.8mm planar layout. The four-segment bending path design, with each segment having a bending angle of 30°±1°, achieves multi-level deformation buffering and achieves a total thickness of 1.2mm (0.1mm for the spring body plus 1.1mm for the deformation space).

[0037] L-shaped stress relief grooves, 0.2mm wide and 2.8mm long, are formed on both sides of the spring, with a depth ratio of 1:1.4, reducing the stress peak by 35% (FEA verification); the L-shaped stress grooves are further reduced by four bends, decreasing the effective projected area by 63% (7.6 × 1.8mm). 2 );

[0038] The rounded corner design incorporates a 0.5mm radius at the root of the bend, and the rounded corner surface is electropolished to a thickness of less than 0.2μm to reduce crack initiation.

[0039] The ultra-thin material process of SUS304 foil with cold work hardening treatment (hardness HV420±20) uses a four-step precision bending die and a 32° pre-compensation angle to offset springback, which increases the springback speed by 40% and achieves accurate waveform reproduction within 5ms (measured amplitude fluctuation rate is less than 5%). The four-station die plus 32° pre-compensation controls the bending angle tolerance within ±1° (CPK≥1.67).

[0040] In summary, the spring adopts a double Y-shaped elastic unit 2 folding method and L-shaped stress relief groove 3 to form a composite system of "elastic main chain plus stress branch chain". Then, the ultra-thin material is cold-worked and four-segment bending to achieve the unity of "high strength and high precision". Finally, the stiffness formula is reverse-engineered to match the mainstream motor parameters (mover mass 2-5g).

[0041] The two ends of the first shaft piece 22 are connected to the spring base piece 1 and the connecting piece 24 respectively. The spring base piece 1 and the first shaft piece 22 are connected by a bending zone 1 21 with a bending angle of 35°. The first shaft piece 22 and the connecting piece 24 are connected by a bending zone 23 with a bending angle of 35°. The bending direction of the bending zone 23 is opposite to that of the bending zone 1 21.

[0042] The two ends of the second shaft piece 26 are connected to the connecting piece 24 and the welding piece 28 respectively. The connecting piece 24 and the second shaft piece 26 are connected by a bending zone 3 25 with a bending angle of 30°. The second shaft piece 26 and the welding piece 28 are connected by a bending zone 4 27 with a bending angle of 30°. The bending direction of the bending zone 4 27 is opposite to that of the bending zone 3 25, and the bending direction of the bending zone 3 25 is opposite to that of the bending zone 23. The bending zone 3 25 and the bending zone 23 are located on the same side of the connecting piece 24.

[0043] The 0.1mm material is folded four times in a double Y-shape, achieving an equivalent linear stroke of 2.4mm within a free height of 1.2mm (the stroke-to-height ratio of traditional structures is 1:1). The axial stiffness is jointly controlled by the bending angle (30°) and the groove length (2.8mm), and is decoupled from the free height. When achieving a stiffness of 150N / m, the free height is reduced by 40% compared to traditional solutions. The 1.2mm free height structure is compatible with fully automated mounting processes (vacuum nozzle gripping qualification rate > 99.9%), and the mounting accuracy requirement is reduced by 50% compared to traditional springs (allowing a positioning deviation of ±0.1mm).

[0044] In this design, the spring is made of a material with a thickness of 0.1mm, achieving extremely thin material and a single piece weighing only 18mg. The structure is compact with a free height of 1.2mm. While maintaining a vibration stroke of 0.4mm, the axial space is compressed by 40%, achieving stress space optimization. At the same time, through the design of four-segment bending and L-shaped stress groove 3, a three-level stress gradient distribution is achieved within a free height of 1.2mm, increasing the effective stress zone ratio to 82%, compared to only 60% in traditional folding structures. The 30° stepped bending and R0.5 rounded corners disperse the maximum stress to below 480MPa (FEA simulation verification).

[0045] The table below compares the spring performance parameters of this solution with those of traditional springs to visually demonstrate the improved value of the springs in this solution:

[0046]

[0047] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A high-stability spring structure for a thin linear vibration motor, characterized in that, It includes a spring substrate (1), on both sides of which Y-shaped elastic units (2) are symmetrically arranged; The Y-shaped elastic unit (2) includes a first shaft piece (22), a connecting piece (24), a second shaft piece (26), and a welding piece (28); The two ends of the first shaft piece (22) are connected to the spring base piece (1) and the connecting piece (24) respectively, and the two ends of the second shaft piece (26) are connected to the connecting piece (24) and the welding piece (28) respectively.

2. The high-stability spring structure for a thin linear vibration motor according to claim 1, characterized in that, The side of the connecting piece (24) is provided with an L-shaped stress groove (3) located between the first shaft piece (22) and the second shaft piece (26).

3. The high-stability spring structure for a thin linear vibration motor according to claim 1, characterized in that, The spring base plate (1) and the first shaft plate (22) are connected by a bending zone (21), and the bending angle of the bending zone (21) is 35°.

4. The high-stability spring structure for a thin linear vibration motor according to claim 3, characterized in that, The first shaft piece (22) and the connecting piece (24) are connected by a second bending zone (23), and the bending angle of the second bending zone (23) is 35°.

5. The high-stability spring structure for a thin linear vibration motor according to claim 4, characterized in that, The bending direction of the second bending zone (23) is opposite to that of the first bending zone (21).

6. The high-stability spring structure for a thin linear vibration motor according to claim 4, characterized in that, The connecting piece (24) and the second shaft piece (26) are connected by a three-bending zone (25), the bending angle of which is 30°.

7. The high-stability spring structure for a thin linear vibration motor according to claim 6, characterized in that, The second shaft piece (26) and the welding piece (28) are connected by a four-bending zone (27), the bending angle of which is 30°.

8. The high-stability spring structure for a thin linear vibration motor according to claim 7, characterized in that, The bending direction of the fourth bending zone (27) is opposite to that of the third bending zone (25).

9. The high-stability spring structure for a thin linear vibration motor according to claim 6, characterized in that, The bending direction of the third bending zone (25) is opposite to that of the second bending zone (23).

10. The high-stability spring structure for a thin linear vibration motor according to claim 6, characterized in that, The bending zone 3 (25) and bending zone 2 (23) are located on the same side of the connecting piece (24).

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