Multi-section nonlinear stiffness hourglass spring

Abstract

A multi-section nonlinear rigidity hourglass spring comprises a conical rubber body, a supporting plate and a mounting plate, the middle of the conical rubber body is a hollow vibration reduction area, the supporting plate and the mounting plate are arranged in parallel, the conical rubber body is connected between the supporting plate and the mounting plate in a vulcanized mode, and a rubber stopping piece is arranged in the middle of the hollow vibration reduction area of the conical rubber body. A first vibration reduction gap is formed between the side face of the rubber stop piece and the inner side face of the conical rubber body, and a second vibration reduction gap is formed between the top face of the rubber stop piece and the installation face where the installation plate is located. According to the hourglass spring provided by the invention, the rubber stop piece is arranged in the middle of the hollow vibration reduction area in the rubber body. When the hourglass spring is subjected to a large load, the inner side face of the rubber body can make contact with the rubber stop piece to form a section of non-linear variable stiffness, after the rubber stop piece makes contact with a metal piece on the mounting face where the mounting plate is located, another section of non-linear variable stiffness can be provided, and the non-linear change range of the stiffness is large.

Description

Technical Field

[0001] The invention relates to the technical field of rail vehicle vibration damping parts, in particular to a multi-section nonlinear stiffness hourglass spring. Background Art

[0002] The hourglass spring is a secondary suspension damping device for rail vehicles. Its basic structure is a rubber body vulcanized and connected between a support plate and a mounting plate arranged in parallel. The rubber body is a symmetrically distributed cone structure, and the middle of the rubber body is an empty damping area. The load deformation of the rubber body is used to provide flexible support for the vehicle to improve the comfort of the vehicle during driving and provide stiffness requirements under different loads. Since the vehicle is under different loads, the relevant damping devices need to provide a certain nonlinear change stiffness to meet different stiffness requirements, so matching nonlinear stiffness design in the development of hourglass springs is of great significance.

[0003] Through searching, technical documents on hourglass springs and variable stiffness designs have been disclosed in the prior art. For example, the utility model authorization announcement document with publication number "CN207526919U" and the name "hourglass spring and vehicle with hourglass spring". The hourglass spring disclosed therein has a small vertical stiffness and can replace the low stiffness characteristics of coil spring steel, and there is no sudden breakage. However, its stiffness tends to change linearly and cannot provide nonlinear variable stiffness. When the vehicle load changes significantly, it will not meet the application requirements.

[0004] For example, the invention patent publication document with the publication number "CN110762149A" and the name "A nonlinear mitigation variable stiffness hourglass spring". In the disclosed technical solution, the upper elastic body has an upper variable stiffness part for nonlinear mitigation variable stiffness, and the lower elastic body has a lower variable stiffness part for nonlinear mitigation variable stiffness; the upper elastic body also has an upper compression-expandable body, the upper variable stiffness part is an upper variable stiffness tray, and the outer periphery of the upper variable stiffness tray is an annular upper variable stiffness edge; the bottom of the upper compression-expandable body is connected to the upper variable stiffness tray inside the upper variable stiffness edge; the lower elastic body also has a lower compression-expandable body at the bottom, the lower variable stiffness part is a lower variable stiffness tray, and the outer periphery of the lower variable stiffness tray is an annular lower variable stiffness edge; the bottom of the lower compression-expandable body is connected to the lower variable stiffness tray inside the lower variable stiffness edge. This comparative document can contact the variable stiffness tray to provide nonlinear variable stiffness when the compression-expandable body is loaded and deformed. Although nonlinear stiffness change can be achieved, the range of change is small. After the variable stiffness tray and the compression-expandable body come into contact, another stage of nearly linear stiffness change is presented.

[0005] For example, the invention patent publication document with the publication number "CN115782946A" and the name "An hourglass spring for secondary vibration reduction". In the technical solution disclosed in this comparative document, a stopper fixed on the mounting plate is used to provide nonlinear stiffness changes. However, since the stopper needs to be assembled between a specific connecting plate and a mounting plate, the overall structure of the hourglass spring is complex and the installation is cumbersome. In addition, since the stopper is set on the mounting plate, it generates nonlinear variable stiffness when it contacts the rubber body, and has a larger variable stiffness range than the second comparative document, but the stopper cannot contact any metal parts, and the variable stiffness range is still limited. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a multi-section nonlinear stiffness hourglass spring, comprising a conical rubber body with a hollow vibration damping zone in the middle and a support plate and a mounting plate arranged in parallel, the conical rubber body being vulcanized and connected between the support plate and the mounting plate, a rubber stopper being provided in the middle of the hollow vibration damping zone of the conical rubber body, a first vibration damping gap being formed between the side surface of the rubber stopper and the inner side surface of the conical rubber body, a second vibration damping gap being formed between the top surface of the rubber stopper and the mounting surface where the mounting plate is located, and the spring has at least a first nonlinear stiffness when the first vibration damping gap is zero, and has at least a second nonlinear stiffness when the second vibration damping gap is zero.

[0007] Furthermore, the top surface of the rubber stopper includes a first arc surface.

[0008] Furthermore, the side surface of the rubber stopper and the inner side surface of the conical rubber body are connected via a first transition arc surface.

[0009] Furthermore, the side surface of the rubber stopper is a first inclined surface, the first inclined surface has a first inclination angle relative to the central axis of the hourglass spring, and the first inclination angle is an acute angle.

[0010] Furthermore, there is a second inclination angle between the inner side surface of the conical rubber body and the central axis of the hourglass spring, and the second inclination angle is smaller than the first inclination angle.

[0011] Furthermore, the first inclined surface is an arc-shaped convex surface, and the inner side surface of the conical rubber body is an arc-shaped concave surface.

[0012] Furthermore, the first transition arc surface is concave to form an annular gap groove, and the annular gap groove and the first inclined surface and the inner side surface of the conical rubber body are all transitioned by arc surfaces.

[0013] Furthermore, a second arc surface is provided as a transition between the first inclined surface and the first arc surface.

[0014] Furthermore, the support plate surface has an annular protrusion.

[0015] Furthermore, the top surface of the annular protrusion is an arc surface, the inner side surface is an inclined surface with a third inclination angle, the outer side surface of the conical rubber body has a fourth inclination angle, and the third inclination angle is smaller than the fourth inclination angle.

[0016] Compared with the prior art, the technical solution of the present application has the following beneficial effects: the hourglass spring provided by the present invention has a rubber stopper in the middle of the internal air damping area of ​​the rubber body. When the hourglass spring is subjected to a large load, the inner side of the rubber body can contact the rubber stopper to form a section of nonlinear variable stiffness. After the rubber stopper contacts the metal part of the mounting surface where the mounting plate is located, another section of nonlinear variable stiffness can be provided. The nonlinear stiffness variation range is large, which solves the problem of insufficient nonlinear stiffness variation in the prior art. In addition, the hourglass spring has good structural integrity, no redundant assembly structure, and is easy to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : Schematic diagram of hourglass spring structure provided in Embodiment 1 and Embodiment 3; Figure 2 : Figure 1 Partial magnified image; Figure 3 : Partial structural principle of the hourglass spring rubber body and rubber stopper provided in Example 2 Figure 1 ; Figure 4 : Partial structural principle of the hourglass spring rubber body and rubber stopper provided in Example 2 Figure 2 . DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] like Figure 1 and Figure 2 A multi-stage nonlinear stiffness hourglass spring comprises a conical rubber body 1 with a hollow vibration damping zone in the middle, and a support plate 2 and a mounting plate 3 arranged in parallel. The conical rubber body 1 is vulcanized and connected between the support plate 2 and the mounting plate 3. A rubber stopper 4 is provided in the middle of the hollow vibration damping zone of the conical rubber body 1. A first vibration damping gap S1 is formed between the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1. A second vibration damping gap S2 is formed between the top surface of the rubber stopper 4 and the mounting surface where the mounting plate 3 is located. When the first vibration damping gap S1 is zero, at least the first nonlinear stiffness is present. When the second vibration damping gap S2 is zero, at least the second nonlinear stiffness is present.

[0020] Generally speaking, the hourglass spring is a vertically symmetrical structure, with the mounting plates 3 being vertically distributed on both sides of the support plate 2, and the conical rubber body 1 being symmetrically vulcanized and connected between the mounting plate 3 and the support plate 2 relative to the support plate 2. The rubber stopper 4 of the hourglass spring provided by the present invention is arranged in the middle of the air damping area of ​​the conical rubber body 1, that is, it is integrally formed with the entire conical rubber body 1. On the one hand, the entire hourglass spring has no other assembly structure, and after the conical rubber body 1 and the mounting plate 3 and the support plate 2 are vulcanized and connected, it forms a whole, which is convenient for installation and use in the secondary suspension of the vehicle.

[0021] When the hourglass spring is loaded, when it is subjected to a smaller load, the conical rubber body 1 begins to deform and compress, providing the hourglass spring with a relatively linear stiffness. When the load increases, the deformation of the conical rubber body 1 increases, and its inner side begins to approach the side of the rubber stopper 4. When the first vibration damping gap S1 is zero, that is, the inner side of the conical rubber body 1 and the side of the rubber stopper 4 are in contact, because the two sides of the rubber stopper 4 are contacted and gradually squeezed by the inner side of the conical rubber body 1, the rubber stopper 4 has a larger stiffness because it is a solid rubber with no air direction. At this time, the hourglass spring begins to show a significant nonlinear variable stiffness. During the period when the inner side of the conical rubber body 1 and the side of the rubber stopper 4 are constantly in contact, the hourglass spring begins to have a second section of nearly linear stiffness. When subjected to a larger load, the distance between the rubber stopper 4 and the mounting surface where the mounting plate 3 is located gradually decreases. When the second vibration damping gap S2 is zero, the top surface of the rubber stopper 4 begins to conflict with the mounting surface where the mounting plate 3 is located, and at this time, another significant nonlinear variable stiffness is provided for the hourglass spring. It should be noted that the mounting surface where the mounting plate 3 is located is not necessarily the mounting plate 3 itself. In this embodiment, the mounting plate 3 is an annular mounting plate with a central opening. However, in actual installation and use, the mounting plate 3 will be installed on a metal mounting surface. When the aforementioned larger load occurs, the top surface of the rubber stopper 4 conflicts with the metal mounting surface to provide a significant nonlinear and larger stiffness. Therefore, when the aforementioned first vibration damping gap S1 is zero and the second vibration damping gap S2 is zero, the hourglass spring will have two significant nonlinear stiffness changes, and the stiffness when the second vibration damping gap S2 is zero will be significantly greater than the stiffness when the first vibration damping gap S1 is zero, so the problem of insufficient nonlinear stiffness change in the prior art can be solved. Combined with the nearly linear stiffness of the conical rubber body 1 itself, the hourglass spring provided by the present invention has a multi-stage nonlinear variable stiffness property, and can be applied to application conditions that require a larger amplitude or richer variable stiffness.

[0022] The following describes the embodiments of the present invention respectively through several different embodiments.

[0023] Embodiment 1: Figure 1 and Figure 2 shown.

[0024] The top surface of the rubber stopper 4 preferably includes a first arc surface 41. In this embodiment, the rubber stopper 4 can be a protrusion that is partially spherical as a whole, so that when a large load occurs, its top surface and the mounting surface where the mounting plate 3 is located will contact in a gradually fitted state after the collision to provide a larger variable stiffness. The spherical protrusion of the rubber stopper 4 will not have excessive stress concentration during the aforementioned contact process, which has a positive effect on its fatigue performance. In addition, in the stage after the first vibration reduction gap S1 is zero, the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1 will also gradually fit together, so that the stiffness change in this stage will be more linear.

[0025] In the above embodiment, the rubber stopper 4 and the inner side surface of the conical rubber body 1 will be continuously compressed and squeezed due to the change of load, and there will be a certain stress concentration phenomenon at the connection between the two, which may be cracked and damaged in the long run. In order to solve this problem, the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1 are connected by a first transition arc surface 11 to eliminate stress concentration as much as possible.

[0026] Embodiment 2: Figure 3 and Figure 4 shown.

[0027] In the above embodiment, although the side of the rubber stopper 4 and the inner side of the conical rubber body 1 are connected by the first transition arc surface 11, stress concentration can be eliminated to a certain extent. However, since the rubber stopper 4 is a spherical protrusion as a whole, if the diameter of the first transition arc surface 11 is too large, the first vibration reduction gap S1 will be too large, so that when the load occurs, the side of the rubber stopper 4 and the inner side of the conical rubber body 1 will not be able to contact and fit. Therefore, on this basis, the rubber stopper 4 of this embodiment adopts a more preferred design.

[0028] The side surface of the rubber stopper 4 is a first inclined surface 42, and the first inclined surface 42 has a first inclination angle α relative to the central axis L of the hourglass spring, and the first inclination angle α is an acute angle. The rubber stopper 4 designed in this way will generally present a trapezoidal design. The second vibration-damping gap S2 formed between the first inclined surface 42 and the inner side surface of the conical rubber body 1 will be smaller than that in the first embodiment. It can be understood that when a load occurs, the inner side surface of the conical rubber body 1 will collide with the side surface of the rubber stopper 4 earlier to provide nonlinear variable stiffness.

[0029] Furthermore, the inner side surface of the conical rubber body 1 is an arc-shaped concave surface 43. In the prior art, the inner side surface of the conical rubber body 1 of the hourglass spring is mostly a convex surface, but in this embodiment, it is more preferably designed as an arc-shaped concave surface 43. Because the rubber stopper 4 is a spherical protrusion as a whole, if the inner side surface of the conical rubber body 1 is designed as a convex surface, it will be compressed and deformed under load, which will make the rigidity of the conical rubber body 1 too large, resulting in the rubber stopper 4 being difficult to contact the mounting surface where the mounting plate 3 is located, thereby affecting the final variable rigidity effect.

[0030] Furthermore, the first transition arc surface 11 is concave to form an annular gap groove 44, and the annular gap groove 44 and the first inclined surface 42 and the inner side surface of the conical rubber body 1 are all transitioned by an arc surface. The design of the annular gap groove 44 makes the connection between the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1 have an inward concave empty area. During the extrusion deformation of the two, the existence of the annular gap groove 44 greatly reduces the direct stress between the two, and improves the fatigue performance of this section. Due to the existence of the first inclined surface 42, the contact between the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1 will not be affected. The design of this annular gap groove 44 will be better than the stress relief effect of the first transition arc surface 11 in the first embodiment. Preferably, the annular gap groove 44 can be designed as a teardrop-shaped profile, that is, the spacing at the bottom of the groove is larger and the spacing at the opening is smaller, so that the opening of the annular gap groove 44 will fit in contact and gradually transition to the inside of the groove under the action of load, and there will be an empty area at its bottom to relieve stress.

[0031] Furthermore, there is a second inclination angle β between the inner side surface of the conical rubber body 1 and the central axis L of the hourglass spring, and the second inclination angle β is smaller than the first inclination angle α. With such a design, a progressive profile will be formed between the inner side surface of the conical rubber body 1 and the first inclined surface 42. When the load occurs, at the stage when the second vibration damping gap S2 is zero, the inner side surface of the conical rubber body 1 and the first inclined surface 42 will gradually fit together, and the fitting area and length are larger than those of the first embodiment, and the stiffness change is more linear at this stage.

[0032] Furthermore, the first inclined surface 42 and the first arc surface 41 are transitioned by the second arc surface 45, so that when the side surface of the rubber stopper 4 and the inner side surface of the conical rubber body 1 are in contact with each other, there is a smooth transition and the stiffness change is more linear.

[0033] Embodiment 3: Figure 1 shown.

[0034] On the basis of the above embodiment, the support plate 2 is further optimized to provide more variable stiffness performance. The support plate 2 has an annular protrusion 5 on its surface. The annular protrusion 5 can be a metal protrusion, or a vulcanized rubber layer structure outside the metal protrusion, or a rubber body structure as a whole. When the conical rubber body 1 is deformed under load, its outer side surface can contact the annular protrusion 5 when the load reaches a certain level, thereby providing another nonlinear stiffness change.

[0035] Furthermore, the top surface of the annular protrusion 5 is an arc surface, the inner side surface is an inclined surface with a third inclination angle γ, the outer side surface of the conical rubber body 1 has a fourth inclination angle δ, and the third inclination angle γ is smaller than the fourth inclination angle δ. With such a design, the inner side surface of the annular protrusion 5 and the outer side surface of the conical rubber body 1 are also a progressive profile, that is, the outer side surface of the conical rubber body 1 will gradually fit the inner side surface of the annular protrusion 5, providing a more linear stiffness change at this stage, and also making the outer side surface of the conical rubber body 1 more uniformly stressed after contact, thereby improving its fatigue resistance.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage nonlinear stiffness hourglass spring, comprising a conical rubber body (1) with a hollow vibration damping zone in the middle, and a support plate (2) and a mounting plate (3) arranged in parallel, wherein the conical rubber body (1) is vulcanized and connected between the support plate (2) and the mounting plate (3), and characterized in that: The conical rubber body (1) has a rubber stopper (4) in the middle of the free-side vibration damping area, a first vibration damping gap (S1) is formed between the side surface of the rubber stopper (4) and the inner side surface of the conical rubber body (1), and a second vibration damping gap (S2) is formed between the top surface of the rubber stopper (4) and the mounting surface where the mounting plate (3) is located, and when the first vibration damping gap (S1) is zero, at least a first nonlinear stiffness is present, and when the second vibration damping gap (S2) is zero, at least a second nonlinear stiffness is present.

2. The multi-stage nonlinear stiffness hourglass spring according to claim 1, characterized in that: The top surface of the rubber stopper (4) comprises a first arc surface (41).

3. The multi-section nonlinear stiffness hourglass spring according to claim 2, characterized in that: The side surface of the rubber stopper (4) and the inner side surface of the conical rubber body (1) are connected via a first transition arc surface (11).

4. The multi-section nonlinear stiffness hourglass spring according to claim 3, characterized in that: The side surface of the rubber stopper (4) is a first inclined surface (42), and the first inclined surface (42) has a first inclination angle (α) relative to the central axis (L) of the hourglass spring, and the first inclination angle (α) is an acute angle.

5. The multi-section nonlinear stiffness hourglass spring according to claim 4, characterized in that: There is a second inclination angle (β) between the inner side surface of the conical rubber body (1) and the central axis (L) of the hourglass spring, and the second inclination angle (β) is smaller than the first inclination angle (α).

6. The multi-section nonlinear stiffness hourglass spring according to claim 5, characterized in that: The first inclined surface (42) is an arc-shaped convex surface, and the inner side surface of the conical rubber body (1) is an arc-shaped concave surface (43).

7. The multi-section nonlinear stiffness hourglass spring according to claim 3, characterized in that: The first transition arc surface (11) is concave to form an annular gap groove (44), and the annular gap groove (44) and the first inclined surface (42) and the inner side surface of the conical rubber body (1) are all transitioned by arc surfaces.

8. The multi-stage nonlinear stiffness hourglass spring according to any one of claims 4 to 7, characterized in that: A second arc surface (45) transitions between the first inclined surface (42) and the first arc surface (41).

9. The multi-stage nonlinear stiffness hourglass spring according to any one of claims 1 to 7, characterized in that: The support plate (2) has an annular protrusion (5) on its surface.

10. The multi-section nonlinear stiffness hourglass spring according to claim 9, characterized in that: The top surface of the annular protrusion (5) is an arc surface, the inner side surface is an inclined surface with a third inclination angle (γ), the outer side surface of the conical rubber body (1) has a fourth inclination angle (δ), and the third inclination angle (γ) is smaller than the fourth inclination angle (δ).

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