Wave spring and heat treatment process thereof

Abstract

The invention relates to the related technical field of wave spring processing, and discloses a wave spring and a heat treatment process thereof, and the heat treatment process comprises the following steps: S1, carrying out vacuum heat treatment on production raw materials; according to the method, the alloy ring is subjected to punch forming to generate the trend of axial bending, the alloy ring is subjected to heat setting aging to generate large plastic deformation elastic force, after the inner diameter and the outer diameter of the wave spring are machined to the drawing size, performance correction, shape correction and loading aging of the wave spring are carried out, and the wave spring achieves plastic deformation while the correction meets the drawing size requirement; the final use performance is met, the wave spring generates stable plastic bending deformation, and the specified elastic force requirement is met; therefore, the use size and performance requirements are met, it is guaranteed that the product meets the design requirement, the use requirement and the actual state of the product are met, and the machining yield and performance of the high-temperature alloy wave spring product are improved.

Description

Technical Field

[0001] The invention relates to the technical field related to wave spring processing, in particular to a wave spring and a heat treatment process thereof. Background Art

[0002] As a common elastic mechanical part, springs are indispensable in various industries, from aerospace and nuclear reactors to stationery and children's toys. Existing springs include traditional compression springs and wave springs. Traditional compression springs are helical springs that withstand positive pressure. There is a certain gap between the coils of the compression spring. When subjected to external loads, the spring contracts and deforms to store deformation energy, which is manifested as the external force is proportional to the compression amount, the stiffness is a constant value, and the force-displacement curve is a straight line.

[0003] However, traditional compression springs cannot meet the requirements of complex force-displacement curves. Traditional wave springs are elastic elements with several peaks and valleys on a thin metal ring. The waves between different layers support each other. When subjected to external loads, the height between the peaks and valleys decreases, thereby storing deformation energy. It is manifested as a smooth force-displacement curve with a single stiffness change. It is usually used in situations where the load and deformation are not large, and the spring stiffness is required to be small and an axial preload needs to be applied.

[0004] However, traditional wave springs cannot meet the requirements of large loads. In order to make up for the shortcomings of traditional springs in situations where large loads and stiffness changes are required, it is necessary to propose a spring with large load and deformation, adjustable stiffness and simple structure to adapt to more complex spring demand situations. In order to solve this problem, a wave spring and its heat treatment process are proposed. Summary of the invention

[0005] The present invention provides a wave spring and a heat treatment process thereof, which solve the problems in the above-mentioned background technology.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] A wave spring and a heat treatment process thereof, wherein the heat treatment process steps are as follows:

[0008] S1: Vacuum heat treatment of production raw materials;

[0009] S2: Grinding and leveling the raw materials obtained in S1;

[0010] S3: cutting the raw material obtained in S2 into thin flat washers with a thickness of 1 mm;

[0011] S4: punching the thin flat washer obtained in S3 into a wave spring through a punching die;

[0012] S5: heat setting and aging the wave spring obtained in S4;

[0013] S6: Performing wire cutting processing on the inner ring of the wave spring obtained in S5 by using a wire cutting fixture;

[0014] S7: grinding the outer ring of the wave spring obtained in S6 by a grinding punching die;

[0015] S8: Use the calibration fixture to continuously press the wave spring obtained in S7 down to the rated height 4 to 6 times.

[0016] The wave spring is subjected to pressure correction and shape calibration;

[0017] S9: Load and age the wave spring obtained in S8.

[0018] Preferably, the stamping mold in S4 includes a lower template, a stamping core shaft, a die, a containing frame, a punch, an upper template, a mold handle, a guide pin and a guide sleeve; the upper end of the lower template is coaxially fixedly connected to the stamping core shaft, the die and the containing frame, the die is sleeved on the outer side of the stamping core shaft, the containing frame is sleeved on the outer side of the die, the outer edge of the lower template is vertically fixedly connected to the lower ends of multiple guide pins, the outer side of the upper end of each guide pin is slidably sleeved with a guide sleeve, the upper ends of the multiple guide sleeves are vertically fixedly connected to the upper template, the lower end of the upper template is coaxially fixedly connected to the punch, the punch and the die are cooperatively arranged, and the upper end of the upper template is provided with a mold handle.

[0019] Preferably, S5 comprises the following steps:

[0020] S501: grouping the wave springs obtained in S4 into groups of 5 to 10;

[0021] S502: Install one group of wave springs into a heat setting tooling and perform vacuum heat treatment;

[0022] S503: furnace cooling the wave spring obtained in S502;

[0023] S504: air-cooling the wave spring obtained in S503;

[0024] S505: Repeat S502-S504 for each remaining group of wave springs.

[0025] Preferably, S502 the heat setting tooling includes a heat setting mandrel, a setting sleeve, a second gasket and a second nut; the outer wall of the setting mandrel is integrally provided with a coaxially arranged boss one, the outer side of the setting mandrel is sequentially fitted with a setting sleeve, a second gasket and a second nut, the setting sleeve is placed on the boss one, and the second nut is screwed and locked with the setting mandrel thread; the setting sleeve includes an upper sleeve and a lower sleeve, and the opposite surfaces of the upper sleeve and the lower sleeve are wavy surfaces matched with the wave spring.

[0026] Preferably, S6 the wire cutting fixture comprises a base, a cutting sleeve and a positioning cone sleeve; a placement groove is provided in the middle of the upper surface of the base, a through hole penetrating the placement groove in the middle is provided, and a cutting sleeve with a T-shaped annular structure is provided in the placement groove, and the annular cavity of the cutting sleeve is connected to the through hole of the placement groove with the same diameter, and the annular cavity of the cutting sleeve is matched with the positioning cone sleeve.

[0027] Preferably, S6 the wire cutting fixture comprises a base, a cutting sleeve and a positioning cone sleeve; a placement groove is provided in the middle of the upper surface of the base, a through hole penetrating the placement groove in the middle is provided, and a cutting sleeve with a T-shaped annular structure is provided in the placement groove, and the annular cavity of the cutting sleeve is connected to the through hole of the placement groove with the same diameter, and the annular cavity of the cutting sleeve is matched with the positioning cone sleeve.

[0028] Preferably, the correction fixture S8 includes a correction core shaft, a third washer, a correction sleeve and a fourth nut; the outer wall of the correction core shaft is integrally provided with a coaxially arranged boss three, and the outer side of the correction core shaft is sequentially fitted with a third washer, a correction sleeve and a fourth nut, the third washer is placed on the boss three, and the fourth nut is screwed and locked with the correction core shaft thread.

[0029] Preferably, the S9 comprises the following steps:

[0030] S901: compress the wave spring obtained in S8 to the working height through the heat setting tool;

[0031] S902: subjecting the heat setting tooling to vacuum heat treatment;

[0032] S903: air-cooling the wave spring obtained in S902.

[0033] The advantages and positive effects of the present invention are as follows: the alloy ring is stamped to form an axial bending tendency, and heat-set and aged to produce a large plastic deformation elastic force. After the inner and outer diameters of the wave spring are processed to the drawing dimensions, the performance of the wave spring is corrected, shaped and loaded for aging, so that the wave spring can achieve plastic deformation while meeting the drawing dimension requirements, meet the final use performance, and produce a relatively stable plastic bending deformation of the wave spring, and meet the specified elastic force requirements; therefore, the use size and performance requirements are met, ensuring that the product meets the design requirements, meets the use requirements and actual status of the product, and improves the processing yield and performance of high-temperature alloy wave spring products. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0035] Figure 1 It is a structural schematic diagram of the punching die in the present invention;

[0036] Figure 2 yes Figure 1 Schematic diagram of the structure of the medium heat setting tooling;

[0037] Figure 3 yes Figure 1 Schematic diagram of the connection relationship between the base of the centerline cutting fixture and the cutting sleeve;

[0038] Figure 4 yes Figure 1 Schematic diagram of the structure of the middle positioning cone sleeve;

[0039] Figure 5 yes Figure 1 Schematic diagram of the structure of the grinding punch die;

[0040] Figure 6 yes Figure 1 Schematic diagram of the structure of the center correction fixture;

[0041] The symbols in the accompanying drawings are described as follows:

[0042] 1. Lower template; 10. Second cylindrical pin; 11. Guide pin; 12. Guide sleeve; 13. First cylindrical pin; 14. First washer; 15. First nut; 16. First screw; 17. Forming mandrel; 18. Forming sleeve; 19. Second washer;

[0043] 2. Punching mandrel; 20. Second nut; 21. Base; 22. Cutting sleeve; 23. Third screw; 24. Positioning cone sleeve; 25. Grinding mandrel; 26. Correction mandrel; 27. Third washer; 28. Correction sleeve; 29. ​​Fourth nut;

[0044] 3. Concave die; 32. Grinding sleeve; 34. Third nut;

[0045] 4. Container frame;

[0046] 5. Punch;

[0047] 6. Put on the template;

[0048] 7. Second screw;

[0049] 8. Die handle;

[0050] 9. The third cylindrical pin. DETAILED DESCRIPTION

[0051] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0052] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings:

[0053] Reference Figures 1 to 6 As shown, springs, as a common elastic mechanical part, are indispensable in various industries, from aerospace and nuclear reactors to stationery and children's toys. Existing springs include traditional compression springs and wave springs. Traditional compression springs are helical springs that withstand positive pressure. There is a certain gap between the coils of the compression spring. When subjected to external loads, the spring contracts and deforms to store deformation energy, which is manifested as the external force being proportional to the compression amount, the stiffness being a constant value, and the force-displacement curve being a straight line. However, traditional compression springs cannot meet the requirements of complex force-displacement curves. The traditional wave spring is an elastic element with several peaks and valleys on a thin metal ring, and the waves between different ring layers support each other. When subjected to external loads, the height between the peaks and valleys decreases, thereby storing deformation energy, which is manifested as a smooth force-displacement curve with a single stiffness change. It is usually used in situations where the load and deformation are not large, and the spring stiffness is required to be small and an axial preload needs to be applied. However, the traditional wave spring cannot meet the requirements of large loads. In order to make up for the shortcomings of traditional springs in situations where large loads and stiffness changes are required, it is necessary to propose a spring with large loads and deformations, adjustable stiffness changes and simple structure to adapt to more complex spring demand situations. In order to solve this type of problem, a wave spring and its heat treatment process are proposed, and the heat treatment process steps are as follows:

[0054] S1: Vacuum heat treatment of production raw materials;

[0055] S2: Grinding and leveling the raw materials obtained in S1;

[0056] S3: cutting the raw material obtained in S2 into thin flat washers with a thickness of 1 mm;

[0057] S4: punching the thin flat washer obtained in S3 into a wave spring through a punching die;

[0058] S5: heat setting and aging the wave spring obtained in S4;

[0059] S6: Performing wire cutting processing on the inner ring of the wave spring obtained in S5 by using a wire cutting fixture;

[0060] S7: grinding the outer ring of the wave spring obtained in S6 by a grinding punching die;

[0061] S8: Use the calibration fixture to continuously press the wave spring obtained in S7 down to the rated height 4 to 6 times.

[0062] The wave spring is subjected to pressure correction and shape calibration;

[0063] S9: The wave spring obtained in S8 is subjected to loading and aging. The alloy ring is stamped and formed to produce an axial bending tendency, and heat-set and aged to produce a large plastic deformation elastic force. After the inner and outer diameters of the wave spring are processed to the drawing dimensions, the wave spring is subjected to performance correction, profiling and loading and aging, so that the wave spring can achieve plastic deformation while meeting the drawing dimension requirements, meet the final use performance, and produce a relatively stable plastic bending deformation and meet the specified elastic force requirements. Therefore, the use size and performance requirements are met, ensuring that the product meets the design requirements, meets the product use requirements and actual status, and improves the processing yield and performance of high-temperature alloy wave spring products.

[0064] It should be noted that the punching mold in S4 includes a lower template 1, a punching core shaft 2, a die 3, a frame 4, a punch 5, an upper template 6, a die handle 8, a guide post 11 and a guide sleeve 12; the upper end of the lower template 1 is coaxially fixedly connected with the punching core shaft 2, the die 3 and the frame 4, the die 3 is sleeved on the outer side of the punching core shaft 2, the frame 4 is sleeved on the outer side of the die 3, the outer edge of the lower template 1 is vertically fixedly connected with the lower ends of a plurality of guide posts 11, and each of the upper ends of the guide posts 11 is Guide sleeves 12 are slidably mounted on the outside, and the upper ends of the guide sleeves 12 are vertically fixedly connected to the upper template 6. The lower end of the upper template 6 is coaxially fixedly connected to the punch 5. The punch 5 is matched with the die 3, and a die handle 8 is provided at the upper end of the upper template 6. Judging from the shape of the wave spring, the material is stretched during stamping, and the inner and outer diameters are reduced or enlarged. Therefore, the punching die adopts an intermediate punching core shaft for positioning, which not only reduces the change in the inner diameter of the wave spring, but also reduces the rebound amount.

[0065] Furthermore, the wave shape of the wave spring is formed by die pressing. When designing the die, the wave shape and the chord height HA are mainly considered. The wave shape of the wave spring is usually a sine curve. In order to simplify the calculation and make the die convenient, the sine curve is simplified to an arc for design and manufacturing.

[0066] It should also be noted that the chord height HA of the punching die consists of:

[0067] A: The free height H of the wave spring;

[0068] B: When the wave spring is molded, the rebound amount is the same as that of the cold-rolled spiral spring; therefore, when designing the punching die, the die depth, i.e. the chord height HA, should be deepened to compensate for the free height reduction value H1 after the wave spring rebounds;

[0069] C: After the wave spring is pressed, its free height H is significantly lower than before the pressing. Therefore, a free height reduction H2 is reserved after the pressing. According to previous tests, the chord height HA of the punching die is H+0.1~0.5H. When the thickness δ of the wave spring material is small and the width B is large, the chord height HA takes a small value, otherwise it takes a larger value.

[0070] Furthermore, the die arc R=L2+HA2 / 4HA; in the formula: L is the chord length of the crest or trough at the smooth connection between the crest E and the trough C, wherein: L=πD / 2N, D is the outer diameter of the wave spring, N is the number of crests or troughs, preferably three, and the height difference of the three evenly distributed crests and troughs is within 0.1mm; after many tests and analyses, when the inner diameter d and the outer diameter D of the wave spring both have a single-sided margin of 1mm, the stamping height of the thin flat washer is 9.1mm, and a larger axial elastic force is generated at this time.

[0071] It should be noted that when in use, the thin flat washer obtained by S3 is put on the outside of the punching core shaft 2 and placed on the die 3, and then the upper mold plate 6 is released to drive the punch 5 to cooperate with the die 3 to mold the thin flat washer into a wave spring with a height of HA1; when the wave spring with a height of HA1 is subjected to a spring compression force of P(N)(43±3N), the spring compression height is Hb.

[0072] The containing frame 4 is mainly used for positioning the punch 5 and the die 3; the outer edge of the lower die plate 1 is vertically fixedly connected to the lower ends of a plurality of guide pillars 11 uniformly distributed along its circumference, and a guide sleeve 12 is slidably mounted on the outer side of the upper end of each guide pillar 11, and the upper ends of the plurality of guide sleeves 12 are vertically fixedly connected to the upper die plate 6, and the lower end of the upper die plate 6 is coaxially fixedly connected to the punch 5 by a second screw 7 and a cylindrical pin 2 10, the punch 5 is cooperatively arranged with the die 3, and the upper end of the upper die plate 6 is provided with a die handle 8 by a cylindrical pin 3 9.

[0073] It is worth mentioning that in the S5 process, the wave spring after molding is mainly subjected to stress relief and aging by heat treatment. After shaping and aging, the mechanical properties and use characteristics of the wave spring can be improved, and the size of the wave spring can be stabilized.

[0074] And, S501: grouping the wave springs obtained in S4 into groups of 5 to 10;

[0075] S502: Install one group of wave springs into a heat setting tooling and perform vacuum heat treatment;

[0076] S503: furnace cooling the wave spring obtained in S502;

[0077] S504: air-cooling the wave spring obtained in S503;

[0078] S505: Repeat S502-S504 for each remaining group of wave springs; the above process can lay a foundation for the wave spring to be finalized and achieve performance standards.

[0079] In addition, if the wave spring after heat setting cannot fully meet the wave spring performance and wave size requirements, it is necessary to grind and repair the shaping tooling according to the actual elastic force and the peak and trough height values. During the repair, attention should be paid to the smoothness of the arc and the multiple peaks or troughs should be at the same height to ensure the integrity of the wave spring during shaping.

[0080] The heat-setting tooling includes a heat-setting mandrel 17, a shaping sleeve 18, a second gasket 19 and a second nut 20; the outer wall of the shaping mandrel 17 is integrally provided with a coaxially arranged boss 1, and the outer side of the shaping mandrel 17 is fitted with a shaping sleeve 18, a second gasket 19 and a second nut 20 in sequence, the shaping sleeve 18 is placed on the boss 1, and the second nut 20 is threadedly screwed and locked with the shaping mandrel 17; the shaping sleeve 18 includes an upper sleeve and a lower sleeve, and the opposing surfaces of the upper sleeve and the lower sleeve are wavy surfaces matched with the wave spring; when in use, a group of wave springs are placed in the wavy surface between the upper sleeve and the lower sleeve, and then the shaping sleeve 18 is locked by the second nut 20, and then the entire heat-setting tooling is placed in a vacuum heat treatment furnace.

[0081] It should be noted that when using a grinding punching die to grind the outer diameter of the wave spring, it is also necessary to do it at the rated compression amount, and clamping processing is performed on every 5-10 wave springs as a group. The grinding punching die includes a grinding mandrel 25, a grinding sleeve 32, a concave-convex washer 42 and a third nut 34; the outer wall of the grinding mandrel 25 is integrally provided with a coaxially arranged boss 2, and the outer side of the grinding mandrel 25 is sequentially fitted with a grinding sleeve 32, a concave-convex washer 42 and a third nut 34, the grinding sleeve 32 is matched with the boss 2, and the third nut 34 is threadedly screwed and locked with the grinding mandrel 25; the concave-convex washer 42 is used to ensure concentricity and uniform compression.

[0082] When in use, the wave spring obtained in S6 is sleeved on the outside of the grinding mandrel 25 and placed between the second boss and the grinding sleeve 32. After being locked by the third nut 34, the outer ring of the wave spring is ground by a grinder.

[0083] The wave spring is cured by heat treatment with compression deformation. The mechanical properties and use characteristics of the wave spring can also be improved after loading and aging, and its performance can be cured while stabilizing the size of the wave spring.

[0084] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the embodiments described in the specific implementation manners. Any other implementation manners derived by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. A wave spring and a heat treatment process thereof, characterized in that: The heat treatment process steps are as follows: S1: Vacuum heat treatment of production raw materials; S2: Grinding and leveling the raw materials obtained in S1; S3: cutting the raw material obtained in S2 into thin flat washers with a thickness of 1 mm; S4: punching the thin flat washer obtained in S3 into a wave spring through a punching die; S5: heat setting and aging the wave spring obtained in S4; S6: Performing wire cutting processing on the inner ring of the wave spring obtained in S5 by using a wire cutting fixture; S7: grinding the outer ring of the wave spring obtained in S6 by a grinding punching die; S8: Press the wave spring obtained in S7 to the rated height 4 to 6 times continuously through the correction fixture to perform pressure correction and shape correction on the wave spring; S9: Load and age the wave spring obtained in S8.

2. A wave spring and heat treatment process thereof according to claim 1, characterized in that: The punching mold described in S4 comprises a lower template (1), a punching core shaft (2), a die (3), a frame (4), a punch (5), an upper template (6), a die handle (8), a guide column (11) and a guide sleeve (12); the upper end of the lower template (1) is coaxially fixedly connected with the punching core shaft (2), the die (3) and the frame (4); the die (3) is sleeved on the outer side of the punching core shaft (2); the frame (4) is sleeved on the outer side of the die (3); the outer edge of the lower template (1) is vertically fixedly connected with the lower ends of a plurality of guide columns (11); the outer side of the upper end of each guide column (11) is slidably sleeved with a guide sleeve (12); the upper ends of the plurality of guide sleeves (12) are vertically fixedly connected with the upper template (6); the lower end of the upper template (6) is coaxially fixedly connected with the punch (5); the punch (5) and the die (3) are cooperatively arranged; and the upper end of the upper template (6) is provided with a die handle (8).

3. A wave spring and heat treatment process thereof according to claim 1, characterized in that: The S5 comprises the following steps: S501: grouping the wave springs obtained in S4 into groups of 5 to 10; S502: Install one group of wave springs into a heat setting tooling and perform vacuum heat treatment; S503: furnace cooling the wave spring obtained in S502; S504: air-cooling the wave spring obtained in S503; S505: Repeat S502-S504 for each remaining group of wave springs.

4. A wave spring and heat treatment process thereof according to claim 3, characterized in that: S502 The heat-setting tooling includes a heat-setting core shaft (17), a setting sleeve (18), a second gasket (19) and a second nut (20); the outer wall of the setting core shaft (17) is integrally provided with a coaxially arranged boss one, and the outer side of the setting core shaft (17) is fitted with a setting sleeve (18), a second gasket (19) and a second nut (20) in sequence, the setting sleeve (18) is placed on the boss one, and the second nut (20) is screwed and locked with the setting core shaft (17); the setting sleeve (18) includes an upper sleeve and a lower sleeve, and the opposite surfaces of the upper sleeve and the lower sleeve are wave surfaces matched with the wave spring.

5. A wave spring and heat treatment process thereof according to claim 4, characterized in that: S6 The wire cutting fixture comprises a base (21), a cutting sleeve (22) and a positioning cone sleeve (24); a placement groove is provided in the middle of the upper surface of the base (21), a through hole is provided in the middle of the placement groove which runs through the thickness direction thereof, a cutting sleeve (22) having a T-shaped annular structure is provided in the placement groove, the annular cavity of the cutting sleeve (22) is connected with the through hole of the placement groove in the same diameter, and the annular cavity of the cutting sleeve (22) is matched with the positioning cone sleeve (24).

6. A wave spring and heat treatment process thereof according to claim 5, characterized in that: S7 The grinding punching die comprises a grinding mandrel (25), a grinding sleeve (32), a concave-convex washer (42) and a third nut (34); the outer wall of the grinding mandrel (25) is integrally provided with a coaxially arranged boss 2, and the outer side of the grinding mandrel (25) is sequentially fitted with a grinding sleeve (32), a concave-convex washer (42) and a third nut (34); the grinding sleeve (32) is matched with the boss 2, and the third nut (34) is threadedly screwed and locked with the grinding mandrel (25).

7. A wave spring and heat treatment process thereof according to claim 6, characterized in that: S8 The correction fixture comprises a correction core shaft (26), a third gasket (27), a correction sleeve (28) and a fourth nut (29); the outer wall of the correction core shaft (26) is integrally provided with a coaxially arranged boss three, and the outer side of the correction core shaft (26) is fitted with a third gasket (27), a correction sleeve (28) and a fourth nut (29) in sequence, the third gasket (27) is placed on the boss three, and the fourth nut (29) is screwed and locked with the correction core shaft (26).

8. A wave spring and heat treatment process thereof according to claim 7, characterized in that: The S9 comprises the following steps: S901: compress the wave spring obtained in S8 to the working height through the heat setting tool; S902: subjecting the heat setting tooling to vacuum heat treatment; S903: air-cooling the wave spring obtained in S902.

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