A multi-layer constant force volute spring and a production process thereof

Abstract

The present application relates to a kind of multilayer constant force scroll spring and its production process, including several coil springs;Several described coil springs are successively stacked and are refuted into shape, and the two ends of coil spring are fixed respectively.The beneficial effects of the present application are that:1.thin single-layer coil spring is stacked after forming the constant force scroll spring with consistent bending radius, compared with directly using thicker spring, the forming method of the present application can make the scroll spring curl to small volume more, to realize the increase of its torsion in the case of not increasing or increasing less scroll spring volume, meet the industrial needs;2.the torsion of multiple times after stacking can be obtained after the two ends of single-layer coil spring with consistent inner diameter are fixed respectively, meet the requirement of increasing torsion.

Description

Technical Field

[0001] This invention relates to the field of spring technology, and in particular to a multi-layer constant force spiral spring and its manufacturing process. Background Technology

[0002] With technological advancements and the increasing variety of product specifications, the widespread use of spiral springs in various products has expanded. Examples include lifting devices for medical beds, lifting devices for large displays, commutators for large, special-purpose AC / DC motors, brush holders supporting brushes on slip rings, high-performance super-stroke suspended window sash balancers, gate cable tensioning devices for large-scale water conservancy projects, carbon slip ring assemblies for wind turbines, and seatbelt height adjusters for automobiles, among others.

[0003] While increasing the number of springs or improving spring materials can certainly provide elasticity, increasing the number of springs is generally limited by installation space, and improving spring materials usually significantly increases manufacturing costs. Increasing the torque by increasing the thickness of a single spring layer has certain limitations in production and cannot achieve the required small-scale specifications. Therefore, the above-mentioned technical methods cannot meet customer needs in many cases.

[0004] Chinese utility model patent CN2388411Y discloses a staggered steel strip spiral spring cylinder. The spring steel strip is fixed to the mandrel and outer shell by rivets. The spring steel strip consists of two or more layers, with varying lengths in each layer. One end of all the strips is stacked and fixed to the mandrel, while the other end of the longest strip is fixed to the outer shell. The other ends of the remaining strips are freely unwound. This design allows for control of the output torque within a specified range where variations are approximately constant, making it suitable for mechanical products requiring constant elastic force for drive or energy storage.

[0005] However, because the spiral spring cylinder has a freely unwinding end, when the outermost end is pulled, the freely unwinding end on the inner side does not apply pressure to the outer end. Therefore, its effect of increasing torque is limited and cannot meet the requirements. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention discloses a multi-layer constant force spiral spring and its manufacturing process, which can increase the torque of the spiral spring while minimizing its volume to meet industrial application needs.

[0007] A multi-layer constant force spiral spring includes several spiral springs; the several spiral springs are stacked in sequence and then reversed to form a shape, and the two ends of the spiral springs are fixed respectively.

[0008] A further provision of the above technical solution is that the inner tail of the coil spring is welded and fixed in a stepped shape.

[0009] A further provision of the above technical solution is that the outer side of the coil spring is fixed by a fixing component.

[0010] This invention also discloses a manufacturing process for a multi-layer constant force spiral spring, comprising the following steps:

[0011] 1) Steel strip slicing;

[0012] 2) Trimming: Trim the edges of both sides and make the two ends R-shaped;

[0013] 3) Formed coil spring: Steel strip is formed into a single-layer coil spring using a vortex rolling machine;

[0014] 4) Temperature setting: Place multiple coiled springs in an oven for temperature setting, and then air cool to room temperature;

[0015] 5) Stacking: Stacking one end of several coil springs together and fixing them with a fixing component;

[0016] 6) Reversal: The end with the screw is reversed and attached to the inner ring of the coil spring using a reversal fixture to form a semi-finished product of a multi-layer coil spring;

[0017] 7) Welding: Weld the outer ends of the reversed semi-finished product layer by layer;

[0018] 8) Assembly: The welded semi-finished product is reversed onto the assembly mandrel using a reverse clamp.

[0019] A further setting of the above technical solution is: the hardness of the steel strip is HV540-560.

[0020] A further setting of the above technical solution is: in step 5, the outer end of the coil spring is fixed by a fixing component.

[0021] The above technical solution is further configured as follows: the semi-finished product in step 7 is a multi-layer coil spring with a fixed end in the center and a movable end on the outside.

[0022] The above technical solution is further configured such that the temperature in the oven is set to 300℃~350℃ and the setting time is 100min~150min.

[0023] The above technical solution is further configured such that the temperature in the oven is set to 315℃ and the setting time is 120min.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. By stacking thin single-layer coil springs to form a constant force spiral spring with the same bending radius, compared with directly using a thicker spring, the forming method of the present invention can make the spiral spring curled to a smaller volume, so as to increase its torque without increasing or with a small increase in the volume of the spiral spring, thus meeting industrial needs.

[0026] 2. By fixing the two ends of multiple single-layer coil springs with the same inner diameter respectively, the torque can be multiplied by the sum of the two layers, thus satisfying the requirement to increase the torque. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the semi-finished product.

[0028] Figure 2 This is a schematic diagram of a spiral spring.

[0029] Figure 3 This is a schematic diagram of the anti-rejection fixture.

[0030] The attached diagram is labeled as follows: 100, coil spring; 200, fixing component; 300, assembly mandrel; 400, anti-reverse clamp; 401, slot. Detailed Implementation

[0031] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0032] like Figures 1-3 As shown in the following embodiments, a multilayer constant force spring and its manufacturing process are disclosed.

[0033] Example 1

[0034] Specific reference Figure 2 As shown, a multi-layer constant force spiral spring includes several coil springs 100; the several coil springs 100 are stacked in sequence and then reversed to form a shape, and the two ends of the coil springs 100 are fixed respectively.

[0035] The above is the basic scheme of this embodiment. A combination is formed by stacking several coil springs 100 in sequence. When in use, its torque is the sum of the torques of the multiple coil springs 100, thus increasing the torque.

[0036] If a thick steel strip is directly spiral-wound, the inner diameter of the formed bend is larger due to the thickness of the steel strip, directly leading to an increase in the volume of the spiral spring. Since torque is inversely proportional to the inner diameter of the bend, the torque decreases as the inner diameter of the bend increases. However, a spiral spring formed by stacking layers has a smaller inner diameter for both the single-layer and stacked constant-force spiral springs. Therefore, the extension torque reaches its maximum value, and the volume of the spiral spring is only slightly larger than that of a single-layer spiral spring, meeting the requirement for a small volume in use.

[0037] The reversal is an assembly method used when multiple single-layer coil springs 100 are stacked. The specific operation is as follows: the outer end of the first single-layer coil spring 100 is fixed to the reversal fixture 400, and then the outer end of the second single-layer coil spring 100 is also fixed to the same reversal fixture 400 and located at the center of the reversal fixture 400, and the fixed sections overlap, that is, the inner end face of the second single-layer coil spring 100 is in close contact with the outer end face of the first single-layer coil spring 100. The above process is repeated. After the outer ends of several single-layer coil springs 100 are fixed, the coiled parts of multiple single-layer coil springs 100 are operated simultaneously to wrap around the outer periphery of the reversal fixture 400, so that the surfaces of adjacent coil springs 100 are in close contact, and the assembly is completed.

[0038] In this embodiment, the inner tail of the coil spring 100 is welded and fixed in a stepped shape.

[0039] In order to control the torque of the formed spiral spring, it is necessary to ensure that the torque of a single spiral spring 100 is within a certain range. Therefore, the thickness and length of a single spiral spring 100 need to be consistent. During the forming process, the inner diameter of the outer spiral spring 100 is larger, and the inner diameter of the inner spiral spring 100 is smaller. After the outer ends of each spiral spring 100 are flush and fixed, the inner ends of each spiral spring 100 are not in a flush position, but rather present a stepped shape.

[0040] In other embodiments, other fixing methods can be used to fix the inner end of the stepped coil spring 100 without affecting its use.

[0041] The outer side of the coil spring 100 is fixed by the fixing component 200.

[0042] Preferably, in this embodiment, the outer end of the coil spring 100 is fixed by a screw.

[0043] In other embodiments, the outer end of the coil spring 100 may also be secured by other components.

[0044] Preferably, in this embodiment, there are 4 single-layer coil springs 100.

[0045] Example 2

[0046] Specific reference Figures 1-3 As shown, this embodiment discloses a manufacturing process for a multi-layer constant force spiral spring, specifically including the following steps:

[0047] 1) Steel strip slicing;

[0048] 2) Trimming: Trim the edges of both sides and make the two ends R-shaped;

[0049] 3) Formed coil spring 100: The steel strip is formed into a single-layer coil spring 100 by a vortex machine;

[0050] 4) Temperature setting: Place multiple coil springs 100 into an oven for temperature setting, and then air cool to room temperature;

[0051] 5) Stacking: Stack one end of several coil springs 100 and fix them with a fixing component;

[0052] 6) Reversal: The screw-containing end is reversed to the inner ring of the coil spring 100 using the reversal fixture 400 to form a semi-finished product of the multi-layer coil spring 100.

[0053] 7) Welding: Weld the outer ends of the reversed semi-finished product layer by layer;

[0054] 8) Assembly: The welded semi-finished product is reversed onto the assembly mandrel 300 using the reverse clamp 400.

[0055] The above is the basic scheme of this embodiment.

[0056] In step 1, the raw material of the steel strip is cut into several steel strips of the required size, and each steel strip has the same length and width. At the same time, the surface of the steel strip is kept intact and free of obvious defects such as tears or peeling, so that the stress at different locations is the same or similar.

[0057] In step 5, the outer ends of several coil springs 100 are pulled out and stacked flush onto a steel plate or other flat tooling.

[0058] In step 6, the outer end of the stacked coil springs 100 is fixed by the fixing member 200 and installed onto the anti-coupling clamp 400. The portion near the outer end is inserted into the slot 401 of the anti-coupling clamp 400, so that the fixing member 200 is located at the center of the anti-coupling clamp 400. The installed coil springs 100 are then anti-coupling, causing them to coil around the outer periphery of the anti-coupling clamp 400. At this time, the inner end of the formed semi-finished product is the end fixed by the fixing member 200, and the outer end is a movable end without fixing, and the movable end is set in a stepped shape, as shown in the figure. Figure 1 As shown.

[0059] In this embodiment, the anti-reverse clamp 400 has a cylindrical structure and a slot 401 is provided on the side wall. The end of the coil spring 100 can extend into the hollow part of the center 400 of the anti-reverse clamp through the slot 401.

[0060] In step 8, the semi-finished product is placed on the anti-shipment jig 400. The welded end is pulled out and wound onto the assembly mandrel 300. Simultaneously, the assembly mandrel 300 and the anti-shipment jig 400 are rotated, causing the semi-finished product on the anti-shipment jig 400 to be anti-shipped onto the assembly mandrel 300. At this point, the welded end is located at the inner end, tightly against the assembly mandrel 300, and the end fixed by the fixing component 200 is the outer end. (Refer to...) Figure 2 As shown.

[0061] When using it, the outer end of the spiral spring needs to be pulled uniformly. Therefore, before reversing, the inner end of the single-layer spiral spring 100 needs to be flush to form an end.

[0062] When directly forming a spiral spring using a thick steel strip, the large thickness of the steel strip results in a larger bending inner diameter, directly increasing the volume of the spiral spring. Since torque is inversely proportional to the bending inner diameter, the torque decreases as the bending inner diameter increases. However, a spiral spring formed by stacking layers has a smaller inner diameter for each single-layer spring 100, meaning the bending inner diameter of the stacked constant-force spring is also smaller. Therefore, the extension and contraction torque reaches its maximum value. Furthermore, the stacking method only requires that the volume of the original single-layer spring 100 after forming is not significantly different from the original single-layer spring 100, thus meeting the industrial need for spiral springs with small volume and high torque.

[0063] Preferably, the steel strip has a hardness of HV540-560.

[0064] Preferably, in this embodiment, the straightness of the side of the steel strip is ≤4 / 1000, which can ensure the toughness of the steel strip.

[0065] In this embodiment, in step 5, the outer end of the coil spring 100 is fixed by the fixing component 200.

[0066] In other embodiments, the outer end of the coil spring 100 may also be secured by other components.

[0067] In this embodiment, the semi-finished product in step 7 is a multi-layer coil spring 100 with a fixed end in the center and a movable end on the outside.

[0068] In this embodiment, the temperature in the oven is set to 300℃~350℃, and the setting time is 100min~150min.

[0069] Preferably, the oven is set at a temperature of 315°C and a setting time of 120 minutes.

[0070] By shaping and then air-cooling to room temperature, the shaping performance and color of the single-layer coil spring 100 are guaranteed to be golden yellow.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A manufacturing process for a multi-layer constant force spiral spring, comprising a plurality of spiral springs (100); characterized in that: Several coil springs (100) are stacked in sequence and then reversed to form a shape, with the two ends of each coil spring (100) fixed respectively; It also includes the following steps: 1) Steel strip slicing; 2) Trimming: Trim the edges of both sides and make the two ends R-shaped; 3) Formed coil spring (100): The steel strip is formed into a single-layer coil spring (100) by a vortex machine; 4) Temperature setting: Place multiple coil springs (100) into an oven for temperature setting, and then air cool to room temperature; 5) Stacking: Stack one end of several coil springs (100) and fix them by fixing component (200); 6) Reversal: The end with the screw is reversed to the inner ring of the coil spring (100) by the reversal jig (400) to form a semi-finished product of the multi-layer coil spring (100); 7) Welding: Weld the outer ends of the reversed semi-finished product layer by layer; 8) Assembly: The welded semi-finished product is reversed onto the assembly mandrel (300) using the reverse clamp (400).

2. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: The inner tail of the coil spring (100) is welded and fixed in a stepped manner.

3. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: The outer side of the coil spring (100) is fixed by a fixing component (200).

4. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: The steel strip has a hardness of HV540-560.

5. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: In step 5), the outer end of the coil spring (100) is fixed by the fixing component (200).

6. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: The semi-finished product in step 7 is a multi-layer coil spring (100) with a fixed end in the center and a movable end on the outside.

7. The manufacturing process of the multi-layer constant force spiral spring according to claim 1, characterized in that: The oven is set at a temperature of 300℃~350℃ and a setting time of 100min~150min.

8. The manufacturing process of the multi-layer constant force spiral spring according to claim 7, characterized in that: The oven is set at 315℃ and the setting time is 120 minutes.

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