Compound buffer spring with variable pitch and tapering wire diameter

Abstract

The utility model relates to composite buffer spring technical field, proposes a kind of composite buffer spring with variable pitch and gradually changing line diameter, including two connecting top plates, the outer ring spring for buffering is commonly connected between two the connecting top plates, a plurality of first buffer springs and second buffer springs are provided between two connecting top plates and are staggered, by the setting of first buffer spring and second buffer spring and so on structure of staggered arrangement, when impact load is small, mainly by the elastic deformation of outer ring spring;With the increase of compression stroke, the spring module inside the inside staggered successively participates in deformation, at the end of stroke, the semicircular web plate and so on structure inside each spring module are mutually contacted and provide rigid support, so that the overall support force is significantly increased with impact intensity smoothly, efficiently respond to the wide load from slight vibration to violent impact, solve the problem of insufficient impact absorption and single energy consumption mode in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of composite buffer spring technology, specifically to a composite buffer spring with variable pitch and gradually changing wire diameter. Background Technology

[0002] In the field of mechanical engineering, especially in vehicle suspension, heavy equipment, and vibration isolation systems for precision instruments, the performance of damping springs directly determines the vibration reduction effect, stability, and reliability of the entire system. Traditional constant-pitch helical springs, due to their linear relationship between load and deformation, often exhibit insufficient adaptability, a simplistic damping curve, and a tendency to resonate when dealing with complex and variable loads, particularly impact loads. To overcome these shortcomings and achieve nonlinear variable stiffness characteristics, the industry has undertaken numerous innovations, one mainstream approach being the development of variable-pitch springs made of composite materials.

[0003] In the prior art, a utility model patent with patent number CN201851569U and titled "Variable Pitch Helical Metal-Rubber Composite Spring" provides a typical solution. This technology aims to solve the problems of high energy consumption, low efficiency, and high noise in nonlinear applications caused by constant pitch springs. Its core solution is: a steel wire wound into a variable pitch helical metal spring serves as the skeleton, and then a layer of rubber material is wrapped around it, forming a metal-rubber composite. This structure combines, to a certain extent, the load-bearing capacity of a metal spring and the damping characteristics of a rubber material. Through the variable pitch design of the spring itself and the nonlinear deformation of the rubber layer, it achieves the goal of "variable stiffness," where the system stiffness changes with the increase or decrease of load, and also has the effect of vibration absorption and noise reduction.

[0004] Existing variable pitch composite springs suffer from core limitations in their cushioning performance: they rely on the overall deformation of a single spring body and rubber layer, resulting in gradual stiffness changes and a lack of active multi-stage triggering mechanisms, making it difficult to achieve an ideal cushioning curve and leading to insufficient absorption efficiency for large impacts. Furthermore, their internal structure is merely a material composite, lacking a phased mechanical interaction structure, resulting in a single energy dissipation method and limited design space for nonlinear characteristics. In addition, this structure lacks built-in guidance, making its resistance to eccentric loads and long-term stability highly dependent on external mechanisms, and it is susceptible to instability and wear risks under complex operating conditions. These shortcomings have spurred the demand for novel composite spring structures with active multi-stage cushioning, built-in guidance, and greater design flexibility. Utility Model Content

[0005] This invention proposes a composite buffer spring with variable pitch and gradually changing wire diameter, which solves the problems of insufficient impact absorption and single energy consumption mode in related technologies.

[0006] The technical solution of this utility model is as follows: a composite buffer spring with variable pitch and gradually changing wire diameter, comprising two connecting top plates; An outer ring spring for buffering is connected between the two connecting top plates. Several staggered first buffer springs and second buffer springs are arranged between the two connecting top plates. The first buffer springs and second buffer springs, together with the outer ring spring, provide composite buffering.

[0007] As a preferred embodiment of this utility model, a sliding shaft and an inner hole shaft are respectively provided on one side of the two connecting top plates, and the sliding shaft is inserted into the interior of the inner hole shaft.

[0008] As a preferred embodiment of this utility model, an arc-shaped groove is provided on one side of the connecting top plate, and the two ends of the outer spring are disposed inside the two arc-shaped grooves.

[0009] In a preferred embodiment of this utility model, a female bolt connector is fixedly connected to the center of the connecting top plate, and two bolt sub-connectors are fixedly connected to the ends of the first buffer springs located at both ends. The female bolt connector and the bolt sub-connectors are fixedly connected by bolts.

[0010] As a preferred embodiment of this utility model, the first buffer spring is composed of two circular first buffer connecting pieces and a first arc-shaped buffer wall, with the two first buffer connecting pieces fixedly connected to the upper and lower ends of the first arc-shaped buffer wall. An upper semi-circular connecting plate and an upper semi-circular inner plate are fixedly connected to the inner wall of the first buffer connecting piece located at the upper end, and a lower semi-circular connecting plate and a lower semi-circular inner plate are fixedly connected to the inner wall of the first buffer connecting piece located at the lower end.

[0011] In a preferred embodiment of this utility model, the upper semi-arc connecting plate is connected to the lower semi-arc connecting plate, the upper semi-arc inner plate is connected to the lower semi-arc inner plate, and a contact groove is provided at the connection between the upper semi-arc connecting plate and the lower semi-arc connecting plate and at the connection between the upper semi-arc inner plate and the lower semi-arc inner plate. A plurality of circumferentially distributed and staggered first buffer grooves are provided on the first arc-shaped buffer wall, and a first inner through hole is provided on the first buffer connecting piece. The inner hole shaft and the sliding shaft both pass through the interior of the first inner through hole.

[0012] As a preferred embodiment of this utility model, the second buffer spring is composed of two circular second buffer connecting pieces and a second arc-shaped buffer wall, with the two second buffer connecting pieces fixedly connected to the upper and lower ends of the second arc-shaped buffer wall; The upper staggered arc-shaped connecting plate and the upper staggered semi-arc inner plate are fixedly connected to the inner wall of the second buffer connecting plate located at the upper end, and the lower staggered arc-shaped connecting plate and the lower staggered semi-arc inner plate are fixedly connected to the inner wall of the second buffer connecting plate located at the lower end.

[0013] In a preferred embodiment of this utility model, the upper staggered arc-shaped connecting plate and the upper staggered semi-arc inner plate are connected to each other, the upper staggered semi-arc inner plate and the lower staggered semi-arc inner plate are connected to each other, a plurality of circumferentially distributed staggered second buffer grooves are provided on the second arc-shaped buffer wall, and a second inner through hole is provided on the second buffer connecting piece, and the inner hole shaft and the sliding shaft both pass through the interior of the second inner through hole.

[0014] 1. This utility model, through the staggered arrangement of the first buffer spring and the second buffer spring, etc., when the impact load is small, the outer spring mainly undergoes elastic deformation; as the compression stroke increases, the internal staggered spring modules participate in the deformation one after another. At the end of the stroke, the semi-arc connecting plates and other structures inside each spring module contact each other and provide rigid support, so that the overall support force increases smoothly and significantly with the impact intensity, effectively coping with a wide range of loads from slight vibration to severe impact.

[0015] 2. This utility model, through the setting of arc-shaped buffer walls, semi-arc connecting plates and other structures, guides the wall surface to generate nonlinear bending deformation during compression to dissipate energy; at the same time, the connecting plate structures inside each module and between modules contact at predetermined stroke points, further consuming energy and changing the force flow path through structural interference and friction, thereby achieving richer nonlinear damping characteristics that go beyond the deformation of a single material. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the installation structure of the first buffer spring and the second buffer spring of this utility model; Figure 3 This is a schematic diagram of the overall structure of the connecting top plate of this utility model; Figure 4 This is a schematic diagram of the overall structure of the first and second buffer springs of this utility model; Figure 5 This is a front view of the overall structure of the first and second buffer springs of this utility model; Figure 6 This utility model Figure 5 Sectional view at point AA; Figure 7 This is a cross-sectional view of the first buffer spring of this utility model; Figure 8 This is a cross-sectional view of the second buffer spring of this utility model.

[0018] In the diagram: 1. Connecting top plate; 11. Bolt female connector; 12. Arc groove; 13. Sliding shaft; 14. Inner hole shaft; 2. Outer coil spring; 3. First buffer spring; 30. Bolt joint; 31. First buffer connecting piece; 32. First arc-shaped buffer wall; 33. Upper semi-arc connecting plate; 34. Lower semi-arc connecting plate; 35. Contact groove; 36. Upper semi-arc inner plate; 37. Lower semi-arc inner plate; 38. First inner through hole; 39. First buffer groove; 4. Second buffer spring; 41. Second buffer connecting piece; 42. Second arc-shaped buffer wall; 43. Upper staggered arc-shaped connecting plate; 44. Lower staggered arc-shaped connecting plate; 45. Upper staggered semi-arc inner plate; 46. Lower staggered semi-arc inner plate; 47. Second inner through hole; 48. Second buffer groove. Detailed Implementation

[0019] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model.

[0020] Example like Figures 1-8 As shown, a composite buffer spring with variable pitch and gradually changing wire diameter includes two connecting top plates 1; An outer ring spring 2 for buffering is connected between the two connecting top plates 1. Several first buffer springs 3 and second buffer springs 4 are arranged alternately between the two connecting top plates 1. The first buffer springs 3 and second buffer springs 4 together with the outer ring spring 2 perform compound buffering.

[0021] A composite buffer spring device with variable pitch and gradually changing wire diameter is disclosed. The core of the device lies in its composite buffer structure, which mainly consists of two parallel connecting top plates 1 forming a load-bearing base. Between the two connecting top plates 1, there is a common outer spring 2, which serves as the main buffer element. The outer spring 2 is responsible for bearing and attenuating most of the external load. To provide multi-level and non-linear buffering characteristics, several first buffer springs 3 and second buffer springs 4 are also arranged in the space between the two connecting top plates 1. The first buffer springs 3 and second buffer springs 4 are arranged in an alternating manner. When the device is subjected to axial compression, the outer spring 2 first undergoes elastic deformation. As the compression stroke increases, the alternating first and second buffer springs 4 successively contact and participate in the deformation, so that the outer spring 2 works together with the multiple sets of internally alternating springs to form a composite buffer. The outer spring 2 provides initial, relatively soft stiffness, while the internally alternating spring sets gradually intervene in the subsequent stroke, providing increasing support force, thereby achieving a buffering effect of variable pitch and gradually changing stiffness, effectively coping with impacts of different intensities.

[0022] A sliding shaft 13 and an inner shaft 14 are respectively provided on one side of the two connecting top plates 1, with the sliding shaft 13 inserted into the inside of the inner shaft 14.

[0023] On opposite sides of the two connecting top plates 1, a sliding shaft 13 and an inner bore shaft 14 are fixedly installed respectively. A cylindrical sliding shaft 13 extends inward from the center of one connecting top plate 1, while a cylindrical inner bore shaft 14 is installed at the corresponding position of the other connecting top plate 1. The inner bore shaft 14 has a smooth cylindrical hole. During device assembly, the sliding shaft 13 is precisely inserted into the inner hole of the inner bore shaft 14 with its outer cylindrical surface, forming a clearance fit or transition fit. This insertion fit between the sliding shaft 13 and the inner bore shaft 14 constitutes the guiding mechanism of the device. When the buffer spring is compressed by external pressure, the two connecting top plates 1 tend to move closer to each other. At this time, the sliding shaft 13 slides axially in the hole of the inner bore shaft 14. Its mating surface plays a guiding and positioning role, ensuring that the entire spring assembly always moves axially during compression and rebound, preventing radial offset, twisting or instability, and ensuring the smoothness and reliability of the buffering process.

[0024] An arc-shaped groove 12 is provided on one side of the top plate 1, and the two ends of the outer spring 2 are located inside the two arc-shaped grooves 12.

[0025] On the inner side of each connecting top plate 1, a specific arc-shaped groove 12 is provided. The radius of curvature of the arc-shaped groove 12 matches the radius of the outer spring 2 wire. The groove depth is sufficient to accommodate and stably support the end of the spring. During assembly, the upper and lower ends of the outer spring 2 are precisely placed into the arc-shaped grooves 12 of the two connecting top plates 1. The arc-shaped grooves 12 effectively limit and fix the ends of the outer spring 2, preventing them from slipping or shifting during operation. External force is directly transmitted to the ends of the outer spring 2 through the connecting top plate 1, and the spring undergoes compression deformation, thereby converting mechanical energy into the elastic potential energy of the spring and realizing the buffering function.

[0026] A bolt female connector 11 is fixedly connected to the center of the connecting top plate 1, and two bolt sub-connectors 30 are fixedly connected to the ends of the first buffer springs 3 located at both ends. The bolt female connector 11 and the bolt sub-connector 30 are fixedly connected by bolts.

[0027] At the center of each connecting top plate 1, a bolt female connector 11 is fixedly connected. The connector has a threaded hole inside. Corresponding to the two first buffer springs 3 located at the uppermost and lowermost ends, a bolt sub-connector 30 is fixedly connected to its end. The sub-connector has a through hole in its center. During installation, the through hole on the bolt sub-connector 30 is aligned with the threaded hole on the bolt female connector 11. Then, a standard bolt is passed through the through hole and screwed into the threaded hole. By tightening the bolt, a preload is generated, thereby firmly fixing and clamping the end of the first buffer spring 3 to the connecting top plate 1. The bolt connection method provides a robust and reliable mechanical connection, ensuring that the first buffer spring 3 will not loosen from the main structure during repeated buffering cycles.

[0028] The first buffer spring 3 is composed of two circular first buffer connecting pieces 31 and a first arc-shaped buffer wall 32. The two first buffer connecting pieces 31 are fixedly connected to the upper and lower ends of the first arc-shaped buffer wall 32. An upper semi-circular connecting plate 33 and an upper semi-circular inner plate 36 are fixedly connected to the inner wall of the first buffer connecting plate 31 located at the upper end, and a lower semi-circular connecting plate 34 and a lower semi-circular inner plate 37 are fixedly connected to the inner wall of the first buffer connecting plate 31 located at the lower end.

[0029] The first buffer spring 3 is an independent elastic module. Its main structure consists of two annular first buffer connecting pieces 31 and a first arc-shaped buffer wall 32 connecting the two connecting pieces. The two first buffer connecting pieces 31 are parallel and coaxially arranged, and the first arc-shaped buffer wall 32 is located between them. Its upper and lower edges are fixedly connected to the two connecting pieces, thus forming a cylindrical structure with axial elasticity. In order to enhance the hierarchical nature of its internal support and buffering, an upper semi-arc connecting plate 33 and an upper semi-arc inner plate 36 are fixedly connected to the inner wall surface of the upper first buffer connecting piece 31. Similarly, a lower semi-arc connecting plate 34 and a lower semi-arc inner plate 37 are fixedly connected to the inner wall surface of the lower first buffer connecting piece 31. These semi-arc connecting plates and semi-arc inner plates all extend toward the center of the module. The semi-arc connecting plates are located radially inward closer to the central axis, while the semi-arc inner plates are located radially outward.

[0030] The upper semi-arc connecting plate 33 is connected to the lower semi-arc connecting plate 34, and the upper semi-arc inner plate 36 is connected to the lower semi-arc inner plate 37. The connection between the upper semi-arc connecting plate 33 and the lower semi-arc connecting plate 34 and the connection between the upper semi-arc inner plate 36 and the lower semi-arc inner plate 37 are provided with contact grooves 35. The first arc-shaped buffer wall 32 is provided with a number of circumferentially distributed and intersecting first buffer grooves 39. The first buffer connecting piece 31 is provided with a first inner through hole 38. The inner hole shaft 14 and the sliding shaft 13 both pass through the interior of the first inner through hole 38.

[0031] In the initial state or under small load, the first buffer spring 3 deforms as a whole elastic unit. As the compression increases, its internal components begin to interact. The upper semi-arc plate 33 extending from the top and the lower semi-arc plate 34 extending from the bottom will approach and eventually contact each other near the central axis. Similarly, the upper semi-arc inner plate 36 and the lower semi-arc inner plate 37 also contact each other in a similar manner at a slightly outward position. The contact area of ​​these two pairs of plates forms a specific contact groove 35 structure, which essentially provides alignment and limiting space for the contact surface to ensure smooth contact. At the same time, several grooves machined on the first arc-shaped buffer wall 32... The first buffer grooves 39, which are evenly distributed and staggered around the circumference, serve as stress concentration areas and pre-set deformation guidance areas. When the pressure increases, the arc-shaped buffer wall preferentially undergoes elastic bending or wrinkling deformation at the locations of these grooves, absorbing more energy and achieving a variable pitch buffering effect. In addition, the first inner through holes 38 opened on the two first buffer connecting pieces 31 provide channels for the sliding shaft 13 and the inner hole shaft 14 that pass through the entire device. The sliding shaft 13 and the inner hole shaft 14 pass through these through holes, which not only play the aforementioned overall guiding role, but also limit the excessive radial deformation of the first buffer spring 3 module, so that it mainly undergoes the axial compression and wall bending deformation expected in the design.

[0032] The second buffer spring 4 is composed of two circular second buffer connecting pieces 41 and a second arc-shaped buffer wall 42. The two second buffer connecting pieces 41 are fixedly connected to the upper and lower ends of the second arc-shaped buffer wall 42. The upper staggered arc-shaped connecting plate 43 and the upper staggered semi-arc inner plate 45 are fixedly connected to the inner wall of the upper second buffer connecting plate 41, and the lower staggered arc-shaped connecting plate 44 and the lower staggered semi-arc inner plate 46 are fixedly connected to the inner wall of the lower second buffer connecting plate 41.

[0033] The second buffer spring 4 is also an independent elastic module, consisting of two annular second buffer connecting plates 41 and a second arc-shaped buffer wall 42 connecting them. The inner wall of the upper second buffer connecting plate 41 is fixed with an upper staggered arc-shaped connecting plate 43 and an upper staggered semi-arc inner plate 45, while the lower one is fixed with a lower staggered arc-shaped connecting plate 44 and a lower staggered semi-arc inner plate 46. When the first buffer spring 3 and the second buffer spring 4 are staggered in the assembly, a gradual and phased increase in stiffness is achieved.

[0034] The upper staggered arc-shaped connecting plate 43 and the upper staggered semi-arc inner plate 45 are connected to each other, and the lower staggered semi-arc inner plate 46 of the upper staggered semi-arc inner plate 45 are connected to each other. The second arc-shaped buffer wall 42 is provided with a number of circumferentially distributed staggered second buffer grooves 48. The second buffer connecting piece 41 is provided with a second inner through hole 47. The inner hole shaft 14 and the sliding shaft 13 both pass through the interior of the second inner through hole 47.

[0035] Inside the second buffer spring 4, the upper staggered arc-shaped connecting plate 43 extending from the upper end and the upper staggered semi-arc inner plate 45 are connected to each other to form the upper component, and the lower staggered semi-arc inner plate 46 extending from the lower end forms the corresponding lower component. During compression, the second buffer grooves 48, which are evenly distributed and staggered on the second arc-shaped buffer wall 42, work on a similar principle to the first buffer groove 39. They dissipate energy and change stiffness characteristics by guiding the wall surface to generate specific nonlinear deformation. The staggered distribution of these grooves helps to make the deformation more uniform and stable. The second inner through hole 47 opened on the second buffer connecting piece 41 has a diameter that matches the sliding shaft 13 and the inner hole shaft 14. When the sliding shaft 13 and the inner hole shaft 14 pass through the through hole, they provide radial constraint for the second buffer spring 4 module, ensuring that during axial compression, the internal staggered arc-shaped connecting plate and other components can move according to the design path and contact and interact with the components of the adjacent first buffer spring 3 module at a predetermined stroke point.

[0036] Working principle: When an external impact force is applied to one of the connecting top plates 1, the two connecting top plates 1 begin to approach each other. At this time, the sliding shaft 13 fixed to one of the connecting top plates 1 immediately slides in the inner hole shaft 14 of the other connecting top plate 1, providing stable axial guidance for the entire compression process and preventing component displacement. The impact force is first transmitted to the outer ring spring 2 through the support surface of the arc groove 12 on the connecting top plate 1, causing it to undergo elastic compression and providing initial, relatively gentle buffering force. At the same time, as the compression stroke increases, multiple first buffer springs 3 and second buffer springs 4, which are staggered between the two connecting top plates 1, begin to gradually participate in the work. The first buffer springs 3 located at the uppermost and lowermost ends are firmly connected to the bolt female joint 11 at the center of the connecting top plate 1 through the bolt sub-joint 30 at their ends. The force is transmitted from this point. Each first buffer spring 3 and second buffer spring 4 undergoes axial compression deformation in its respective first inner through hole 38 and second inner through hole 47, with the sliding shaft 13 and inner hole shaft 14 as guide rods. During this process, the buffer grooves 39 and 48, which are staggered on the first arc-shaped buffer wall 32 of the first buffer spring 3 and the second arc-shaped buffer wall 42 of the second buffer spring 4, guide the wall surface to produce nonlinear bending deformation, absorb energy and change stiffness. As the compression goes deeper, the upper half-arc plate 33 and the lower half-arc plate 34 inside each first buffer spring 3 come into contact at the contact groove 35 in the central area. At the same time, the upper half-arc inner plate 36 and the lower half-arc inner plate 37 also come into contact, forming internal support and increasing its stiffness. Meanwhile, the second buffer spring 4, which intersects with it, also has its internal structures such as the upper interlaced arc-shaped connecting plate 43, the upper interlaced semi-arc inner plate 45, and the lower interlaced semi-arc inner plate 46, which contact and interact with the adjacent first buffer spring 3 at the predetermined stroke point. This mechanism, which intervenes in stages from the outside to the inside through interlaced modules, allows the outer ring spring 2, the first buffer spring 3 group, and the second buffer spring 4 group to work together. The supporting force provided increases smoothly and significantly with the compression stroke, achieving a composite buffering effect of variable pitch and gradual wire diameter, effectively coping with impacts of different intensities. When the external force is removed, the potential energy stored in the elastic deformation of each spring is released. Guided by the sliding shaft 13 and the inner hole shaft 14, all components smoothly return to their positions, ready for the next buffering cycle.

[0037] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A composite buffer spring with variable pitch and gradually changing wire diameter, comprising two connecting top plates (1), characterized in that... ； An outer ring spring (2) for buffering is connected between the two connecting top plates (1). Several first buffer springs (3) and second buffer springs (4) are arranged alternately between the two connecting top plates (1). The first buffer springs (3) and the second buffer springs (4) together with the outer ring springs (2) perform composite buffering.

2. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 1, characterized in that, Each of the two connecting top plates (1) is provided with a sliding shaft (13) and an inner hole shaft (14) on one side, and the sliding shaft (13) is inserted into the interior of the inner hole shaft (14).

3. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 1, characterized in that, An arc-shaped groove (12) is provided on one side of the connecting top plate (1), and the two ends of the outer ring spring (2) are located inside the two arc-shaped grooves (12).

4. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 1, characterized in that, The center of the connecting top plate (1) is fixedly connected to a bolt female connector (11), and the ends of the two first buffer springs (3) located at both ends are fixedly connected to bolt sub-connectors (30). The bolt female connector (11) and the bolt sub-connectors (30) are fixedly connected by bolts.

5. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 2, characterized in that, The first buffer spring (3) is composed of two circular first buffer connecting pieces (31) and a first arc-shaped buffer wall (32). The two first buffer connecting pieces (31) are fixedly connected to the upper and lower ends of the first arc-shaped buffer wall (32). The upper half-arc plate (33) and the upper half-arc inner plate (36) are fixedly connected to the inner wall of the first buffer connecting piece (31) located at the upper end, and the lower half-arc plate (34) and the lower half-arc inner plate (37) are fixedly connected to the inner wall of the first buffer connecting piece (31) located at the lower end.

6. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 5, characterized in that, The upper semi-arc connecting plate (33) is connected to the lower semi-arc connecting plate (34), the upper semi-arc inner plate (36) is connected to the lower semi-arc inner plate (37), and a contact groove (35) is provided at the connection between the upper semi-arc connecting plate (33) and the lower semi-arc connecting plate (34) and the connection between the upper semi-arc inner plate (36) and the lower semi-arc inner plate (37). A plurality of circumferentially distributed and intersecting first buffer grooves (39) are provided on the first arc-shaped buffer wall (32), and a first inner through hole (38) is provided on the first buffer connecting piece (31). The inner hole shaft (14) and the sliding shaft (13) both pass through the interior of the first inner through hole (38).

7. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 2, characterized in that, The second buffer spring (4) is composed of two circular second buffer connecting pieces (41) and a second arc-shaped buffer wall (42). The two second buffer connecting pieces (41) are fixedly connected to the upper and lower ends of the second arc-shaped buffer wall (42). The upper staggered arc plate (43) and the upper staggered semi-arc inner plate (45) are fixedly connected to the inner wall of the second buffer connecting piece (41) located at the upper end, and the lower staggered arc plate (44) and the lower staggered semi-arc inner plate (46) are fixedly connected to the inner wall of the second buffer connecting piece (41) located at the lower end.

8. A composite buffer spring with variable pitch and gradually changing wire diameter according to claim 7, characterized in that, The upper staggered arc-shaped connecting plate (43) and the upper staggered semi-arc inner plate (45) are connected to each other. The upper staggered semi-arc inner plate (45) and the lower staggered semi-arc inner plate (46) are connected to each other. The second arc-shaped buffer wall (42) is provided with a number of circumferentially distributed staggered second buffer grooves (48). The second buffer connecting piece (41) is provided with a second inner through hole (47). The inner hole shaft (14) and the sliding shaft (13) both pass through the interior of the second inner through hole (47).

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