axle spring
By forming an annular elastomer support at the shaft and the lower end of the rigid cylinder to support the elastomer layer, the comfort and durability issues of the shaft spring under full load are solved, achieving excellent nonlinear spring characteristics and improved durability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NITTA CHEM IND PROD CO LTD
- Filing Date
- 2021-09-30
- Publication Date
- 2026-06-09
AI Technical Summary
Existing shaft springs provide good ride comfort when the vehicle is empty, but this is difficult to maintain when the vehicle is fully occupied. Furthermore, there is a risk of elastomer layer creep and peeling, which affects durability.
An annular elastomer support is formed at the lower end of the shaft and the rigid cylinder to support the elastomer layer, forming an alternating layered structure to improve the nonlinear spring characteristics, and the elastomer layer is supported by the elastomer support to prevent peeling and creep.
It increases the compressive load of the shaft spring in the high-load region, enhances the nonlinear spring characteristics, reduces durability risks, and prevents peeling and creep of the elastomer layer.
Smart Images
Figure CN116368056B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a shaft spring suitable for use in vehicles, particularly railway vehicles. Background Technology
[0002] For example, in railway vehicles, it is known that a shaft spring is sandwiched between the bogie frame and the axle-side components to mitigate the impact during vertical movement (see Patent Document 1). Figure 5 If we were to explain the specific structure, it would be as follows: Figure 6 As shown, the bogie 31 includes: a bogie frame 32 that supports the car body; an axle 34 that houses a pair of left and right wheels 33; an axle box 35 that houses a bearing that rotatably supports the axle 34; and an axle spring 36 that is clamped between the bogie frame 32 and the axle box 35.
[0003] Figure 7 This is a longitudinal sectional view of a prior art shaft spring 36. The shaft spring 36 includes: a shaft core (main shaft) 37; an outer cylinder 38 having the same axis P as the shaft core 37; and an elastic portion 41 clamped between the shaft core 37 and the outer cylinder 38. The shaft core 37 includes: a shaft portion 42 on which the elastic portion 41 is fixedly mounted; a flange portion 43 formed below the shaft portion 42; and a shaft base portion 44 connected to the flange portion 43. Recessed bearing portions 45 are formed at both ends of the axle box 35, which can fit into the shaft base portion 44 of the shaft spring 36. The shaft spring 36 is assembled onto the bogie by fixing the shaft base portion 44 of the shaft spring 36 into the bearing portion 45 and mounting the outer cylinder 38 to the side of the bogie frame 32.
[0004] The elastic part 41 has a stacked elastomer structure, which consists of multiple elastomer layers 39 (39a, 39b, 39c, and 39d) and multiple rigid cylinders 40 (40a, 40b, and 40c) stacked concentrically around the axis P. The elastomer layers 39a to 39d and the rigid cylinders 40a to 40c are formed into a cone shape with a V-shaped longitudinal cross-section. Furthermore, the outer peripheral surface of the shaft part 42 contacted by the elastomer layer 39a and the inner peripheral surface of the outer cylinder 38 contacted by the elastomer layer 39d are formed into a conical surface. In addition, the portion of the shaft core 37 other than the part with the elastic part 41 is covered by an elastomer film 46 to protect the shaft core 37.
[0005] As described above, the elastic part 41 has an inclined type of laminated elastic structure with an elastomer layer 39 and a rigid cylinder 40 inclined relative to the axis P. When a load is applied in the direction of the axis P (vertical direction) of the shaft spring 36, such as Figure 8As shown, the elastomer layer 39 undergoes elastic deformation, and the height of the shaft spring 36 changes, resulting in a structure that applies a shear load and a compressive load to the elastic portion 41. The compressive load on the shaft spring 36 increases with the amount of displacement of its height, thus exhibiting nonlinear spring characteristics. The nonlinear spring characteristics of the shaft spring 36 can be adjusted by changing the tilt angle of the elastic portion 41.
[0006] Existing technical documents
[0007] Patent documents
[0008] Patent Document 1: Japanese Patent Application Publication No. 2003-40107 Summary of the Invention
[0009] (a) Technical problems to be solved
[0010] However, for the shaft springs with the above structure, the current situation is as follows: when a softer rubber is used as the elastomer layer in order to provide good ride comfort when the vehicle body weight is small, such as when the vehicle is empty, it is difficult to obtain nonlinear spring characteristics that can maintain good ride comfort when the vehicle body weight is large, such as when the vehicle is fully loaded, simply by adjusting the tilt angle of the elastic part.
[0011] Furthermore, the elastomeric layer is only connected to the shaft, rigid cylinder, or outer cylinder on its inner and outer radial sides, and lacks components that support the elastomeric layer in the axial direction. Therefore, with the use of shaft springs, creep may occur in the elastomeric layer, leading to a deterioration in ride comfort, or delamination may occur between the shaft, the outer circumferential surface of the rigid cylinder, and the elastomeric layer, posing a risk to the durability of the shaft spring.
[0012] Therefore, the present invention aims to provide a shaft spring that has excellent nonlinear spring characteristics and can reduce the risk of affecting durability.
[0013] (II) Technical Solution
[0014] To solve the above problems, as one aspect of the present invention, a shaft spring is provided, comprising: a shaft core, an outer cylinder, and an elastic portion sandwiched between the shaft core and the outer cylinder, wherein the elastic portion has a stacked elastic body structure in which an elastic body layer and a rigid cylinder are stacked in concentric circles, the shaft core has a shaft portion for bonding the elastic body layer, and an annular elastic body support portion extending outward in a radial direction is formed at the lower end of at least one of the shaft portion and the rigid cylinder, and the shaft spring has at least one of the following structures (A) and (B).
[0015] (A) The outer diameter of the elastomeric support is set to be greater than or equal to the opening diameter of the lower end of the rigid cylinder or outer cylinder adjacent to the shaft portion or rigid cylinder on which the elastomeric support is formed in the radial direction, and the elastomeric layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastomeric support is formed is formed to the elastomeric support.
[0016] (B) An elastomer layer is formed in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastomer support portion is formed, and when an axial load is applied to the shaft spring, a portion of the load is applied to the elastomer support portion.
[0017] Alternatively, the following structure can be adopted: the elastomeric support portion and the elastomeric layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastomeric support portion is formed are formed at least to a position perpendicular to the lower end of the rigid cylinder or outer cylinder that is in contact with the outer peripheral surface of the elastomeric layer.
[0018] The following structure can be adopted: at least two adjacent lower ends of the shaft, the rigid cylinder and the outer cylinder are formed with annular elastomeric support portions extending outward in the radial direction, the outer diameter of the elastomeric support portion with the smaller inner diameter of the adjacent elastomeric support portions is formed to be larger than the inner diameter of the elastomeric support portion with the larger inner diameter, and the elastomeric layer is formed in at least a portion of the space between the adjacent elastomeric support portions.
[0019] The following structure can be adopted: annular elastomeric support portions extending outward in a radial direction are formed at the lower ends of the shaft portion, the rigid cylinder, and the outer cylinder, respectively; the outer diameter of the elastomeric support portion with the smaller inner diameter among the adjacent elastomeric support portions is formed to be larger than the inner diameter of the elastomeric support portion with the larger inner diameter; and the elastomeric layer is formed in at least a portion of the space between the adjacent elastomeric support portions.
[0020] The following structure can be adopted: Regarding the elastic layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastic support portion is formed, when the thickness in the radial direction at the lower end position of the rigid cylinder or outer cylinder that is in contact with the outer peripheral surface of the elastic layer is set to D1, and the thickness in the axial direction of the shaft spring is set to D2, the condition (D2 / D1)≧1 is satisfied.
[0021] The structure can be as follows: the elastomeric support is formed such that when the shaft portion or rigid cylinder on which the elastomeric support is formed, and the elastomeric layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder, are in a non-adhesive state, the elastomeric layer can be maintained.
[0022] The structure can be as follows: the elastic support is formed to extend in a direction orthogonal to the axis of the shaft spring.
[0023] The structure can be as follows: the corner between the elastomeric support and the shaft or rigid cylinder on which the elastomeric support is formed is bent.
[0024] (III) Beneficial Effects
[0025] According to one aspect of the present invention, a shaft spring can be obtained which has the following structure: an annular elastic body support portion extending outward in a radial direction is formed at the lower end of at least one of the shaft portion and the rigid cylinder, and the elastic body support portion supports the elastic body layer that is in contact with the outer peripheral surface of the shaft portion or the rigid cylinder on which the elastic body support portion is formed. Therefore, the shaft spring has excellent nonlinear spring characteristics and can reduce the risk of affecting durability. Attached Figure Description
[0026] Figure 1 This is a longitudinal sectional view showing an embodiment of the shaft spring of the present invention.
[0027] Figure 2 It was by Figure 1 An enlarged view of the portion enclosed by circle A.
[0028] Figure 3 It means to Figure 1 A longitudinal sectional view of the shaft spring under load.
[0029] Figure 4 This is a graph showing the changes in the displacement and load of the shaft spring of the present invention.
[0030] Figure 5 It was by Figure 3 An enlarged view of the portion enclosed by circle B.
[0031] Figure 6 This is a side view showing a prior art shaft spring mounted on a bogie for railway vehicles.
[0032] Figure 7 This is a longitudinal sectional view of a shaft spring in the prior art.
[0033] Figure 8 It means to Figure 7 A longitudinal sectional view of the shaft spring under load. Detailed Implementation
[0034] The embodiments of the present invention will be described below with reference to the accompanying drawings. The shaft spring of this embodiment is used in railway vehicles, and its usage is similar to that of other applications. Figure 6 The shaft spring described herein is the same as that in the prior art. That is, in Figure 6The shaft spring of the present invention can be used in place of the shaft spring 36. Figure 1 This is a longitudinal sectional view showing an embodiment of the shaft spring of the present invention.
[0035] like Figure 1 As shown, the shaft spring of this embodiment includes: a shaft core 1, an outer cylinder 2, and an elastic portion 3 sandwiched between the shaft core 1 and the outer cylinder 2. The elastic portion 3 is a laminated elastomer structure consisting of alternating layers of elastomer layers 4 and rigid cylinders 5. The elastomer layers 4 are made of rubber-like elastomers. The rigid cylinders 5 are made of rigid materials such as metal or fiberglass. The shaft core 1, elastomer layers 4, rigid cylinders 5, and outer cylinder 2 all have the same axis P. The direction of the axis P is aligned with the vertical direction. Figure 1 In the diagram, arrow X indicates the up and down direction, X1 indicates the up direction, and arrow X2 indicates the down direction.
[0036] The shaft core 1 is made of metal and includes: a shaft portion 6 on which the elastic part 3 is fixedly mounted, a flange portion formed at the lower end of the shaft portion 6, and a shaft base portion 8 connected to the lower side of the flange portion. The elastic part 3 has a laminated elastomer structure, which is composed of: multiple elastomer layers 4a to 4d (hereinafter referred to as "elastomer layer 4" when describing all elastomer layers) and multiple rigid cylinders 5a to 5c (hereinafter referred to as "rigid cylinder 5" when describing all rigid cylinders) stacked concentrically around the shaft core P.
[0037] The rigid cylinders 5a to 5c are formed into a conical shape with a V-shaped longitudinal cross-section. Furthermore, the outer peripheral surface of the upper part of the shaft portion 6, which is in contact with the elastomer layer 4a, and the inner peripheral surface of the outer cylinder 2, which is in contact with the elastomer layer 4d, are formed into conical surfaces. In this embodiment, annular elastomer support portions 7a to 7e (hereinafter referred to as "elastomer support portion 7") extending radially outward are formed at the lower ends of the shaft portion 6, the rigid cylinders 5a to 5c, and the outer cylinder, respectively. The elastomer support portion 7a also functions as a flange portion of the shaft core 1. In this embodiment, the elastomer layer 4 is vulcanized and bonded to the outer cylinder 2, the rigid cylinder 5, the shaft portion 6, and the elastomer support portion 7; however, this is not a limitation, and adhesives can also be used for bonding.
[0038] In this embodiment, the outer diameter of the elastic support 7 with the smaller inner diameter is larger than the inner diameter of the elastic support 7 with the larger inner diameter. Furthermore, the elastic layer 4 located between adjacent elastic support 7s is formed to at least a portion of the space where adjacent elastic support 7s overlap when the shaft spring is viewed from above. The fact that the elastic layer 4 is formed to a portion of the space between adjacent elastic support 7s means that a portion of this space is filled with a rubber-like elastomer in the overall height direction (vertical direction X) of the space. The cross-sectional shape of the elastic layer 4 thus formed is approximately L-shaped.
[0039] According to the above structure, the elastomer layer 4 is formed onto the elastomer support portion 7 formed on the shaft portion 6 or rigid cylinder 5 that is in contact with the inner peripheral surface of the elastomer layer 4. In other words, the elastomer layer 4 is supported by the shaft portion 6 or rigid cylinder 5 and the elastomer support portion 7 that are in contact with its inner peripheral surface. As a result, when a load is applied to the shaft spring, the compressive load increases and the spring constant increases in the high load region compared to shaft springs with existing structures, exhibiting excellent nonlinear spring characteristics. In addition, since the elastomer layer 4 is supported by the elastomer support portion 7, peeling and creep between the outer peripheral surface of the shaft portion 6 or rigid cylinder 5 and the elastomer layer 4 can be suppressed, reducing the risk of affecting durability.
[0040] Furthermore, in this embodiment, since the elastomer layer 4 is formed in the space formed by the overlapping of adjacent elastomer supports 7, 7 when the shaft spring is viewed from above, the compressive load is further increased in the high load area, resulting in better nonlinear spring characteristics.
[0041] Preferably, the corner between the shaft portion 6, the rigid cylinder 5, or the outer cylinder 2 and the elastomeric support portion 7 formed at its lower end is curved. This allows stress to be dispersed and crack formation to be suppressed when a load is applied to the elastomeric layer 4. The lower end position of the rigid cylinder 5 in this case will be explained using the rigid cylinder 5b as an example. Figure 2 It was by Figure 1 An enlarged view of the portion enclosed by circle A. In this invention, the lower end 5b1 of the rigid cylinder 5b is the point where the double-dotted line L1 passing through the inner circumferential surface of the rigid cylinder 5b intersects with the double-dotted line L2 passing through the lower surface of the elastomeric support 7c when viewed in section. This definition also applies to the other elastomeric supports 5a, 5c, and the lower end of the outer cylinder 2. The dashed line L3 in the figure represents a perpendicular line passing through the lower end 5b1 of the rigid cylinder 5b.
[0042] With the lower ends of the rigid cylinders 5a, 5b, 5c and the outer cylinder 2 designated as 5a1, 5b1, 5c1, and 2a1 respectively, considering the presence of the elastomer layer 4 and elastic deformation, the relationships between the lower ends 5a1, 5b1, 5c1, and 2a1 are set as follows: First, the distance from the axis P to each lower end is set to 5a1 < 5b1 < 5c1 < 2a1. That is, the inner diameter of each elastomer support is set to 7a < 7b < 7c < 7d < 7e. Furthermore, the distance from the upper surface of the elastomer support 7a to the upper direction X1 of each lower end is set to 5a1 < 5b1 < 5c1 < 2a1. That is, the height of each elastomer support is set to 7a < 7b < 7c < 7d < 7e.
[0043] In existing shaft springs, such as Figure 7 As shown, the lower ends of the elastomer layers 39a-39d, which are in contact with the inner circumferential surfaces of the rigid cylinders 40a-40c and the outer cylinder 38, are positioned higher than the lower ends of the rigid cylinders 40a-40c and the outer cylinder 38. In contrast, the shaft spring of the present invention is formed such that the lower ends of the elastomer layers 4a-4d, which are in contact with the inner circumferential surfaces of the rigid cylinders 5a-5c and the outer cylinder 2, extend to the elastomer support portions 7a-7d, which are positioned lower than the lower ends of the rigid cylinders 5a-5c and the outer cylinder 2.
[0044] And, as Figure 2 As shown, the elastomeric layer 4, which is connected to the lower end of the rigid cylinder 5 or the outer cylinder 2 and is positioned downwards from that lower end, is formed at a position radially outwards from the lower end of the rigid cylinder 5 or the outer cylinder 2. Thus, as... Figure 3 As shown, when a load is applied to the shaft spring of the present invention, compared with the shaft spring of the prior art, the compressive load increases with the increase of the displacement of the shaft spring, thus exhibiting excellent nonlinear spring characteristics.
[0045] Figure 4 It means when using Figure 1 The shaft spring of the present invention shown is Figure 6 The diagram illustrates the relationship between the vertical displacement of a shaft spring in the X direction and the load on the shaft spring, as shown in the prior art. Solid lines represent the shaft spring of the present invention, while dashed lines represent shaft springs of the prior art. As shown, the shaft spring of the present invention has a lower spring coefficient in the commonly used load region (low load region) compared to prior art shaft springs, and a higher spring coefficient in the high load region. This suppresses the increase in shaft spring displacement. Furthermore, since the elastomer layer 4 is supported by the elastomer support portion 7, peeling and creep between the shaft portion 6 or the outer peripheral surface of the rigid cylinder 5 and the elastomer layer 4 can be suppressed, resulting in excellent durability.
[0046] For the shaft spring of this embodiment, the degree of load in which it achieves a higher spring coefficient can be determined by, for example... Figure 2 As shown, the thickness of the elastic layer 4 in the radial direction at the lower end of the rigid cylinder 5 or outer cylinder 2, which is in contact with the outer peripheral surface of the elastic layer 4, is set to D1, and the thickness in the axial direction P of the elastic layer 4 is set to D2, and the ratio (D2 / D1) is changed for adjustment. Specifically, the larger D2 / D1 is, the more the spring coefficient rise position can be shifted towards the high load region. That is, the larger D2 / D1 is, the more the spring coefficient in the commonly used load region can be maintained and the spring coefficient in the high load region can be increased. In this case, D2 / D1 ≥ 1 is preferred, and D2 / D1 ≥ 1.2 is more preferred.
[0047] Furthermore, in this embodiment, the method of forming an elastomer support 7 at the lower end of the shaft 6, the rigid cylinders 5a-5c, and the outer cylinder 2 has been described. However, it is also possible to provide an elastomer support 7 at the lower ends of at least two adjacent parts of the shaft 6, the rigid cylinders 5a-5c, and the outer cylinder 2. In this case, the spring coefficient of the elastomer layer 4 held by the adjacent elastomer supports 7 can be increased, and the risk of affecting the durability of the elastomer layer 4 can be reduced.
[0048] Alternatively, an elastomer support 7 can be provided at the lower end of at least one of the shaft portion 6, rigid cylinders 5a to 5c, and outer cylinder 2. In this case, it is sufficient to set the outer diameter of the elastomer support 7 to be greater than or equal to the opening diameter of the lower end of the rigid cylinder 5 or outer cylinder 2 adjacent to the shaft portion 6 or rigid cylinder 5 on which the elastomer support 7 is formed in the radial direction, and to form the elastomer layer 4 to the elastomer support 7.
[0049] The elastomeric layer 4, which is in contact with the outer peripheral surface of the shaft portion 6 or rigid cylinder 5 where the elastomeric support portion 7 is formed, is integrally formed continuously from the upper part of the shaft portion 6 or rigid cylinder 5 to the elastomeric support portion 7. The radial thickness of this elastomeric layer 4, which is located downwards from the lower end of the rigid cylinder 5 or outer cylinder 2 in contact with its outer peripheral surface (elastomeric layer 4low), can be appropriately set according to the required nonlinear spring characteristics. However, to increase the spring coefficient in high-load areas, it is preferable to... Figure 2 As shown, the elastomer layer 4 is formed at a position perpendicular to the lower end of the rigid cylinder 5 or the outer cylinder 2 that is in contact with the outer peripheral surface of the elastomer layer 4.
[0050] This condition does not necessarily have to be met under no-load conditions. Typically, considering the elastic deformation of the elastomer, the outer peripheral end face 4out of the elastomer layer 4low is formed as a concave surface. This concave surface will change due to the elastic deformation of the elastomer layer 4. Figure 5As shown, it is planarized. Therefore, it can also be set so that even when there is no load, a portion of the outer peripheral end face 4out of the elastomer layer 4low is closer to the inward side than the vertical line L3, when a load is applied to the shaft spring, the outer peripheral end face 4out of the elastomer layer 4low will reach the position of the vertical line L3 due to elastic deformation.
[0051] Alternatively, in this invention, when a load is applied to the shaft spring in the axial direction, a portion of the load is applied to the elastomer support 7. Specifically, a compressive load is applied to the elastomer support 7 whenever the elastomer layer 4 undergoes elastic deformation. This suppresses excessive deformation of the elastomer layer 4 and reduces the risk of affecting durability.
[0052] In this case, the shapes of the elastomer support 7 and the elastomer layer 4low are not particularly limited, as long as they are formed such that a portion of the axial load (especially the load in the high-load area) applied to the shaft spring is applied to the elastomer support 7. However, the radial width of the elastomer support 7 and the radial thickness of the elastomer layer 4low are preferably at least 1 / 3 of D1, and more preferably at least 1 / 2 of D1. Furthermore, the radial width of the elastomer support 7 refers to (outer diameter - inner diameter) / 2 of the elastomer support 7.
[0053] Furthermore, the elastomeric support 7 can be configured to retain the elastomeric layer 4 when the shaft portion 6 or rigid cylinder 5 to which the elastomeric support 7 is formed, and the elastomeric layer 4 in contact with the outer peripheral surface of the shaft portion 6 or rigid cylinder 5, are in a non-adhesive state. Therefore, even if the elastomeric layer 4 peels off from the outer peripheral surface of the shaft portion 6 or rigid cylinder 5 in contact with its inner peripheral surface, it can prevent the elastomeric layer 4 from detaching from the shaft portion 6 or rigid cylinder 5. That is, it can maintain its function as a shaft spring.
[0054] To ensure that the shape of the elastic support portion 7 can be maintained even when the shaft portion 6 or rigid cylinder 5 with the elastic support portion 7 is peeled off from the outer peripheral surface of the shaft portion 6 or rigid cylinder 5, the shaft spring is manufactured such that any one of the outer peripheral surfaces of the shaft portion 6 or rigid cylinder 5 is not bonded to the elastic layer 4. In this case, products with various shapes of elastic support portions 7 formed on the shaft portion 6 or rigid cylinder 5 that are not bonded to the elastic layer 4 are prepared in advance, and shaft springs with different shapes of elastic support portions 7 are manufactured.
[0055] Furthermore, an elastomer support 7 can be selected such that it maintains the shape of the elastomer layer when a specified load is applied to the shaft spring using a compression testing machine. This test can be performed on each of the elastomer supports 7a to 7d. This method applies not only to cases where the elastomer supports 7 are formed entirely on the shaft portion 6 or the rigid cylinder 5, but also to cases where the elastomer supports 7 are formed on a portion of the component.
[0056] The embodiments of the present invention have been described above, but the scope of the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the invention. For example, in this embodiment, the elastic support 7 is described as extending in a direction orthogonal to the axis P (horizontal direction), but it is not limited thereto, and it can also be formed in a downward inclined manner. In this case, the inclination angle of the elastic support 7 relative to the axis P is set to be larger than the inclination angle of the shaft portion 6 or the rigid cylinder 5 on which the elastic support 7 is formed. The gentler the inclination angle of the elastic support 7, the lower the spring coefficient in the high-load area, so the inclination angle can be appropriately set according to the required nonlinear spring characteristics.
[0057] The constituent elements disclosed in this embodiment and the above-described variations can be combined with each other, and new technical features can be formed through combination.
[0058] Explanation of reference numerals in the attached figures
[0059] 1-Shaft core; 2-Outer cylinder; 3-Elastic part; 4-Elastomer layer; 5-Hard cylinder; 6-Shaft part; 7-Elastomer support part; 8-Shaft base.
Claims
1. A shaft spring comprising: a shaft core, an outer cylinder, and an elastic portion sandwiched between the shaft core and the outer cylinder, the elastic portion having a laminated elastic structure in which an elastomer layer and a rigid cylinder are alternately stacked in concentric circles, the shaft core having a shaft portion for bonding the elastomer layers, and an annular elastomer support portion being formed at the lower end of at least one of the shaft portion and the rigid cylinder, the elastomer support portion extending radially outward in a direction orthogonal to the axis of the shaft spring. The outer diameter of the elastomeric support is set to be greater than or equal to the opening diameter of the lower end of the rigid cylinder or outer cylinder adjacent to the shaft portion or rigid cylinder on which the elastomeric support is formed in the radial direction. In the elastomeric layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastomeric support is formed, the entire surface of the outer peripheral end face of the portion located on the lower side of the rigid cylinder or outer cylinder that is in contact with the outer peripheral surface of the elastomeric layer is formed at least in a position further outward in the radial direction than the position of the following vertical line, which passes through the lower end of the rigid cylinder or outer cylinder that is in contact with the outer peripheral surface of the elastomeric layer.
2. The shaft spring according to claim 1, characterized in that, At least two adjacent lower ends of the shaft, the rigid cylinder, and the outer cylinder are formed with annular elastomeric support portions extending outward in a radial direction. The outer diameter of the elastomeric support portion with the smaller inner diameter is formed to be larger than the inner diameter of the elastomeric support portion with the larger inner diameter. The elastomeric layer is formed in at least a portion of the space between the adjacent elastomeric support portions.
3. The shaft spring according to claim 2, characterized in that, An annular elastomeric support portion extending radially outward is formed at the lower end of the shaft portion, the rigid cylinder, and the outer cylinder, respectively. The outer diameter of the elastomeric support portion with the smaller inner diameter among the adjacent elastomeric support portions is formed to be larger than the inner diameter of the elastomeric support portion with the larger inner diameter. The elastomeric layer is formed in at least a portion of the space between the adjacent elastomeric support portions.
4. The shaft spring according to any one of claims 1 to 3, characterized in that, Regarding the elastomeric layer that is in contact with the outer peripheral surface of the shaft portion or rigid cylinder on which the elastomeric support portion is formed, when the thickness in the radial direction at the lower end position of the rigid cylinder or outer cylinder in contact with the outer peripheral surface of the elastomeric layer is set to D1, and the thickness in the axial direction of the shaft spring is set to D2, the condition (D2 / D1)≥1 is satisfied.
5. The shaft spring according to any one of claims 1 to 3, characterized in that, The corner between the elastomeric support portion and the shaft portion or rigid cylinder on which the elastomeric support portion is formed is bent.
6. The shaft spring according to claim 4, characterized in that, The corner between the elastomeric support portion and the shaft portion or rigid cylinder on which the elastomeric support portion is formed is bent.