A variable stiffness vibration damping pad

Abstract

The purpose of this invention is to provide a vibration damping pad that is simple to manufacture, applicable to most rail transit scenarios, has good vibration reduction effect, and a long service life. Specifically, this invention provides a variable stiffness vibration damping pad, comprising: a body, plate-shaped, wherein the variable stiffness vibration damping pad forms multiple regions with different stiffnesses. These multiple regions with different stiffnesses include at least a low-stiffness region and a high-stiffness region with stiffness higher than the low-stiffness region. The low-stiffness region is located in the middle of the width direction, and the high-stiffness regions are symmetrically arranged at the two edges in the width direction. The low-stiffness region directly corresponds to the rail support area under the sleeper, reducing the overall stiffness of the track system, increasing elasticity, isolating and attenuating impact vibrations from the sleeper, and improving the vibration reduction effect; the high-stiffness region corresponds to the edge of the track slab, providing solid support and improving the safety and stability of train operation.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology and relates to vibration damping pads, specifically a variable stiffness vibration damping pad. Background Technology

[0002] In the field of rail transit, vibration damping pads can be laid between the track base plate and the roadbed to reduce the impact of vibration and reduce noise. They are usually made of rubber material and have concave and convex structures such as protrusions or grooves. The vibration damping effect is achieved by relying on the deformation of the concave and convex structures and the rigidity of the plate itself.

[0003] Traditional vibration damping pads have a uniform stiffness distribution. However, in practical applications, the stress on the pads varies depending on the scenario, and even within the same scenario, different parts of the pad may experience different stresses. For these scenarios, traditional uniform vibration damping pads are insufficient, making it difficult to achieve the desired vibration reduction and noise reduction effect. Summary of the Invention

[0004] The purpose of this invention is to solve the aforementioned problems of the prior art and provide a vibration damping pad that is simple to manufacture, applicable to most rail transit scenarios, has good vibration reduction effect, and a long service life. The specific technical solution is as follows:

[0005] The present invention provides a variable stiffness vibration damping pad, characterized in that it comprises: a body in the shape of a plate, wherein the variable stiffness vibration damping pad is formed with multiple regions of different stiffness, the multiple regions of different stiffness include at least a low stiffness region and a high stiffness region with a stiffness higher than that of the low stiffness region, the low stiffness region is located at the middle position in the width direction, and the high stiffness region is located at the two edge positions in the width direction.

[0006] The variable stiffness vibration damping pad provided by the present invention has multiple regions with different stiffnesses, with the low-stiffness region located in the middle. Therefore, when the variable stiffness vibration damping pad of the present invention is applied in track laying, the low-stiffness region directly corresponds to the rail support area under the sleeper. The vibration energy input in this area is most concentrated. The setting of the low-stiffness region can significantly reduce the overall stiffness of the track system and increase elasticity, thereby more effectively isolating and attenuating the impact vibration from the sleeper and improving the vibration damping effect. In addition, since the high-stiffness region is set at the two edges in the width direction, corresponding to the edge of the track slab during laying, it can provide solid support, which can limit the longitudinal and lateral displacement of the rail and sleeper, and improve the safety and stability of train operation. At the same time, the high-stiffness region can also provide sufficient lateral resistance to prevent the track structure from undergoing excessive deformation or displacement under the action of the train's lateral force.

[0007] The variable stiffness damping pad provided by the present invention may further include a protrusion, which contains a plurality of protrusions disposed on the surface of the body and integrally formed with the body, wherein the plurality of protrusions are distributed in rows and columns and the protrusions are of different sizes, thereby forming a plurality of regions with different stiffness.

[0008] Because different sizes of the protrusions create areas of varying stiffness, even when the vibration damping pad is made of homogeneous material, it is possible to effectively form multiple areas of different stiffness. Thus, without using simple processes or a uniform formula, areas of different stiffness can correspond to different stress parts in actual application scenarios.

[0009] Furthermore, in the variable stiffness damping pad provided by the present invention, the different sizes of the protrusions are due to different top surface dimensions and / or different spacing between the protrusions. Since different protrusion sizes are achieved by setting different top surfaces or spacing, the present invention can use uniform or relatively simple protrusion shapes (such as all protrusions having the same shape, or all protrusions having relatively regular shapes) to achieve different stiffness in different areas, avoiding manufacturing difficulties such as demolding difficulties caused by complex or irregular shapes.

[0010] Preferably, the different top surface dimensions of the protrusions are such that, in regions with different stiffness, the top surface dimension of the protrusion in the region with lower stiffness is smaller than that in the region with higher stiffness. More preferably, the protrusion is frustum-shaped, with a top surface dimension of 10mm-22mm and a bottom surface dimension of 40mm-60mm. Even more preferably, the frustum shape can be a circular frustum, an elliptical frustum, a polygonal frustum, or an irregular frustum.

[0011] Furthermore, preferably, the spacing between the protrusions varies such that, in multiple regions with different stiffness, the spacing between columns of protrusions in the region with lower stiffness is greater than the spacing between columns of protrusions in the region with higher stiffness. More preferably, the spacing between columns of protrusions is 50mm-80mm.

[0012] The variable stiffness vibration damping pad provided by this invention also has the following technical feature: the variable stiffness vibration damping pad is made of rubber, and the content ratio of raw rubber material to filler in the rubber material of different stiffness regions is different. By setting the content ratio of raw rubber material to filler to be different, this invention can form different stiffnesses without changing the shape of each region. Furthermore, it can use molds with a uniform shape during the manufacturing process, thus reducing mold costs and operational complexity.

[0013] Preferably, in the variable stiffness vibration damping pad provided by the present invention, the multiple regions with different stiffnesses also include a medium stiffness region with a stiffness between the low stiffness region and the high stiffness region, and the medium stiffness region is located between the low stiffness region and the high stiffness region. In such a variable stiffness vibration damping pad, the medium stiffness region can guide the stress generated in the low stiffness region at the sleeper location to diffuse more smoothly to the high stiffness regions on both sides, making the pressure distribution more uniform, thereby improving durability and service life.

[0014] More preferably, the width of the low-stiffness zone is 3.5m-4.5m, the width of the medium-stiffness zone is 0.25m-0.35m, and the width of the high-stiffness zone is 0.37m-0.47m. This width arrangement ensures that the high-stiffness, low-stiffness, and medium-stiffness zones are rationally positioned to best correspond to the rail support areas and side edges in various track scenarios, thus allowing each zone to better fulfill its respective function.

[0015] In addition, the variable stiffness vibration damping pad provided by the present invention may also have the following technical features: the main body is an integral structure, or the main body contains multiple rubber layers and at least two fiber layers, with the fiber layers sandwiched between the rubber layers. Attached Figure Description

[0016] Figure 1 This is a front view structural diagram of the variable stiffness vibration damping pad according to Embodiment 1 of the present invention.

[0017] Figure 2 This is a side view of the variable stiffness vibration damping pad according to Embodiment 1 of the present invention.

[0018] Figure 3 yes Figure 1 Enlarged view of part A in the middle. Detailed Implementation

[0019] The terminology used in this invention, unless otherwise stated, generally has the meanings commonly understood by those skilled in the art. In the following embodiments, various processes, methods, and materials not described in detail are all conventional techniques known in the art.

[0020] The specific embodiments of the present invention will be described below with reference to the examples and accompanying drawings.

[0021] <Example 1>

[0022] Figure 1 This is a front view structural diagram of the variable stiffness vibration damping pad according to Embodiment 1 of the present invention. Figure 2 This is a side view of the variable stiffness vibration damping pad according to Embodiment 1 of the present invention.

[0023] like Figure 1-2 As shown, the variable stiffness damping pad 100 in this embodiment is made of rubber material and includes a body 101 and a protrusion 102.

[0024] The body 101 is a planar plate, rectangular in shape, with a thickness of 5mm-12mm, a long side dimension of 4.9m-6.1m, and a short side dimension of 0.8m-2.3m. In this embodiment, the specific thickness is 8mm, and the specific long and short side dimensions are 5.6m and 1.5m, respectively. In actual use, the long side of the body 101 is perpendicular to the length direction of the track, and the short side is parallel to the length direction of the track. For ease of description, the length direction of the track will be referred to as the length direction of the variable stiffness vibration damping pad 100 (i.e., Figure 1 The vertical direction of the track is referred to as the width direction of the variable stiffness damping pad 100 (i.e., the vertical direction). Figure 1 (Left and right directions in the middle).

[0025] The protrusion 102 includes a plurality of protrusions 103 disposed on the upper surface of the body 101 and integrally formed with the body 101. Each protrusion 103 is truncated cone in shape, with its bottom surface integrally formed with the upper surface of the body 101 and its top surface being a circular plane that is substantially parallel to the upper surface of the body 101.

[0026] In this embodiment, regions with different stiffness are formed by the different sizes of the protrusions 103 in the protrusion 102.

[0027] Figure 3 yes Figure 1 Enlarged view of part A in the middle.

[0028] like Figure 1 and Figure 3 As shown, the multiple protrusions 103 on the body 101 are arranged in rows and columns. In this embodiment, the spacing between the protrusions 103 in each row (measured by the distance between the centers of two adjacent protrusions 103 in different rows along the length direction) is the same, which is 50mm-70mm, and 60mm in this embodiment. Furthermore, the bottom surface dimensions (i.e., bottom diameter) of each protrusion 103 are the same, which is 40mm-60mm, and 50mm in this embodiment.

[0029] In this invention, different stiffness regions are formed by the different top surface dimensions of each column of protrusions 103 and the different spacing between each column of protrusions 103, namely two high stiffness regions 1, two medium stiffness regions 2 and one low stiffness region 3.

[0030] The low-stiffness region 3 is located in the middle of the width direction. The high-stiffness region 1 is symmetrically arranged on the left and right edges of the body 101 in the width direction. Two medium-stiffness regions 2 are symmetrically arranged on the left and right sides of the low-stiffness region 3 in the width direction, respectively located between the low-stiffness region 3 and the corresponding high-stiffness region 1. The width dimensions of the low-stiffness region 3, medium-stiffness region 2, and high-stiffness region 1 are 3.5m-4.5m, 0.25m-0.35m, and 0.37m-0.47m, respectively. In this embodiment, the width dimensions of the low-stiffness region 3, medium-stiffness region 2, and high-stiffness region 1 are 4m, 0.325m, and 0.42m, respectively.

[0031] The protrusions 103 in the low-stiffness zone 3 are low-stiffness zone protrusions 1033. The spacing L3 between each column of low-stiffness zone protrusions 1033 (measured as the spacing between two adjacent low-stiffness protrusions 1031 in different columns in the width direction) is 60mm-80mm, specifically 70mm in this embodiment. Furthermore, the top surface dimension (i.e., top surface diameter) D3 of each low-stiffness zone protrusion 1033 is 10mm-14mm, specifically 12mm in this embodiment.

[0032] The protrusions 103 in the medium stiffness zone 2 are medium stiffness zone protrusions 1032. The spacing L2 between each column of medium stiffness zone protrusions 1032 (measured by the spacing between two adjacent medium stiffness zone protrusions 1032 in different columns in the width direction) is smaller than the spacing L3 between each column of low stiffness zone protrusions 1033, which is 55mm-75mm, specifically 65mm in this embodiment. Furthermore, the top surface dimension D2 of each medium stiffness zone protrusion 1032 is larger than the top surface dimension D3 of the low stiffness zone protrusions 1033, which is 16mm-20mm, specifically 18mm in this embodiment.

[0033] The protrusions 103 in the high-stiffness zone 1 are high-stiffness zone protrusions 1031. The spacing L1 between each column of high-stiffness zone protrusions 1031 (measured by the spacing between two adjacent high-stiffness zone protrusions 1031 in different columns in the width direction) is smaller than the spacing L2 between each column of medium-stiffness zone protrusions 1032, which is 50mm-70mm, specifically 60mm in this embodiment. Furthermore, the top surface dimension D1 of each high-stiffness zone protrusion 1031 is larger than the top surface dimension D2 of the medium-stiffness zone protrusions 1032, which is 18mm-22mm, specifically 18mm in this embodiment.

[0034] As described above, in this embodiment, by setting the spacing L3 between the low-stiffness region protrusions 1033, the spacing L2 between the medium-stiffness region protrusions 1032, and the spacing L1 between the high-stiffness region protrusions 1031 to decrease sequentially, while setting the top surface dimension D3 of the low-stiffness region protrusions 1033, the top surface dimension D2 of the medium-stiffness region protrusions 1032, and the top surface dimension D1 of the high-stiffness region protrusions 1031 to increase sequentially, the stiffness of the low-stiffness region 3, the medium-stiffness region 2, and the high-stiffness region 1 is sequentially increased. This stiffness change can be achieved under homogeneous material conditions. Therefore, during manufacturing, a mold of the corresponding shape can be used to manufacture the pad according to conventional rubber molding processes, and a variable stiffness vibration damping pad can be obtained without complex processes.

[0035] Through experimentation, using 100 parts by weight of natural rubber as the main material, 40 parts by weight of filler (including 35 parts by weight of carbon black 660 and 5 parts by weight of silica) as filler, and 3.9 parts by weight of sulfur, accelerators DPG and MBTS as vulcanizing agents, and employing conventional rubber molding methods (mixing time not less than 8 minutes, vulcanization conditions of 155℃ for 20 minutes, and pressure of 15 MPa), the variable stiffness vibration damping pad 100 of this embodiment was manufactured. The stiffness of its low stiffness region 1 is approximately 0.022 N / mm. 3 The stiffness of the intermediate stiffness region 2 is approximately 0.027 N / mm. 3 The stiffness of high-stiffness region 1 is approximately 0.30 N / mm. 3 This satisfies the design requirements of gradually changing stiffness in this invention, and also meets the overall stiffness design requirements of most scenarios in existing rail transit (such as on rigid bridges, vibration-damping sections, etc.).

[0036] Furthermore, in this embodiment, since a low-stiffness zone 1 located in the middle of the width direction, a high-stiffness zone 1 located on both sides of the width direction, and a medium-stiffness zone 2 located on the left and right sides of the low-stiffness zone 3 are provided, the stiffness of the variable stiffness damping pad 100 changes in the width direction to be low in the middle and high on both sides, and there is a medium-stiffness transition region between the high-stiffness region and the low-stiffness region.

[0037] When the variable stiffness vibration damping pad 100 of this embodiment is applied in track laying, the low stiffness zone 1 in the middle can directly correspond to the rail support area under the sleeper. This rail support area is the area where vibration energy input is most concentrated. The low stiffness of the low stiffness zone 1 can significantly reduce the overall stiffness of the track system and increase elasticity, thereby more effectively isolating and attenuating the impact vibration from the sleeper. Especially in the low and medium frequency range (such as below 63Hz) where the vibration reduction requirement is the highest, the vibration reduction effect is very outstanding.

[0038] In addition, the high-rigidity zone 1 on both sides of the track bed after laying corresponds to the edge of the track slab and can provide solid support. On the one hand, this support can limit the longitudinal and lateral displacement of the rails and sleepers and maintain the geometric shape of the track, thereby improving the safety and stability of train operation. On the other hand, it can also provide sufficient lateral resistance to prevent the track structure from undergoing excessive deformation or displacement under the action of lateral forces of the train (such as when turning).

[0039] In other words, the variable stiffness damping pad 100 of this embodiment, with its low stiffness in the middle and high stiffness on both sides, provides the track system with "non-linear" stiffness characteristics in the width direction, making it suitable for track vibration reduction in various scenarios. Under small to medium loads, the middle region of the variable stiffness damping pad 100 deforms, exhibiting soft characteristics to achieve a vibration reduction effect; under extreme or unexpected loads, the load acts on the high stiffness regions on both sides, which can provide sufficient support and stability. Therefore, the variable stiffness damping pad 100 of this embodiment can improve the wheel-rail relationship, that is, help mitigate dynamic impacts between the wheel and rail, reduce the risk of derailment, and thus improve ride comfort.

[0040] Furthermore, the high-stiffness zone 1 enhances overall integrity and fatigue resistance, particularly preventing premature damage to the variable stiffness damping pad 100 due to edge creep and stress concentration. The high stiffness of these two edge sections acts like a "support beam," deforming in conjunction with the low-stiffness zone 3 and medium-stiffness zone 2 in the middle. This effectively reduces uneven settlement of the track structure under long-term cyclic loading, maintaining the overall flatness of the track bed slab. Simultaneously, this high-stiffness zone 1 makes the edge area more stable and less prone to deformation, preventing the damping pad from twisting or shifting, providing a good foundation for maintenance work and reducing the difficulty of maintenance operations.

[0041] In the embodiment, since a medium stiffness zone 2 is also provided between the low stiffness zone 3 in the middle and the high stiffness zone 1 on both sides, this gradual stiffness from the middle to both sides can guide the stress generated at the sleeper position to diffuse more smoothly to both sides, making the pressure distribution more uniform, avoiding local stress peaks, thereby improving the durability and service life of the variable stiffness damping pad 100 itself.

[0042] <Example 2>

[0043] The difference between this embodiment and Embodiment 1 is that Embodiment 1 uses different sizes of protrusions 103 to form regions with different stiffness, while this embodiment uses different materials for the regions to obtain different stiffness. Therefore, this embodiment can use a uniform protrusion size.

[0044] Specifically, the variable stiffness damping pad in this embodiment also includes a high stiffness region, a medium stiffness region, and a low stiffness region. The low stiffness region is located in the middle of the width direction, the high stiffness region is located at the two side edges in the width direction, and the medium stiffness region is located between the high stiffness region and the low stiffness region.

[0045] The high-stiffness, medium-stiffness, and low-stiffness regions are all made of rubber materials, but the proportions of raw rubber (such as natural rubber) and fillers (such as carbon black and silica) differ in these three regions. Specifically, the filler content decreases sequentially from high-stiffness to medium-stiffness to low-stiffness, thus creating regions with different stiffness levels.

[0046] In manufacturing the variable stiffness vibration damping pad of this embodiment, different raw rubber materials, fillers, and other materials can be mixed separately, kneaded, and calendered to form different sheet-shaped rubber blanks. Then, the rubber blanks are cut according to the corresponding length and width dimensions of the high-stiffness, medium-stiffness, and low-stiffness zones. The high-stiffness, medium-stiffness, and low-stiffness zones are placed into a mold according to a predetermined positional relationship (i.e., the low-stiffness zone in the middle, the high-stiffness zones on both sides, and the medium-stiffness zone in between), and then vulcanized together. Before molding, the edges of each rubber blank can be tightly fitted and / or coated with adhesive to improve the overall integrity after vulcanization.

[0047] The above is a detailed description of the embodiments, which is intended to enable those skilled in the art to correctly understand and use the present invention. Any improvements or modifications to technical solutions obtained by those skilled in the art based on the present invention and on the existing technology, without innovative effort but only through analysis, analogy, or limited enumeration, should be within the scope of protection defined by the claims.

[0048] For example, in Embodiment 1, the protrusion 103 is in the shape of a frustum of a cone. This shape provides the most uniform force transmission in all directions, making it the most suitable protrusion shape for the embodiment. However, as an alternative, in other embodiments, the protrusion 103 can also adopt other suitable frustum shapes, such as triangular frustums, square frustums, or other polygonal frustums, or elliptical frustums, irregularly shaped frustums, etc., as long as the top surface dimension changes between the low-stiffness region protrusion 1033, the medium-stiffness region protrusion 1032, and the high-stiffness region protrusion 1031, where the top surface dimension can be the farthest distance between two points on the edge of the top surface of the frustum.

[0049] Furthermore, in Embodiment 1, the width dimensions of the two high-stiffness zones 1 are the same, and the width dimensions of the two medium-stiffness zones 2 are also the same. Alternatively, in other embodiments, the width dimensions of the two high-stiffness zones 1 can be set differently to accommodate different stress conditions at the two edges of the track. Similarly, the width dimensions of the two medium-stiffness zones 2 can also be set differently depending on the stress conditions. For example, at locations such as curves in the track, the high-stiffness zones 1 and medium-stiffness zones 2 on both sides can be set differently to accommodate different stress conditions on both sides of the curve.

[0050] The variable stiffness damping pads in Examples 1 and 2 both have high stiffness, low stiffness, and medium stiffness regions, with the medium stiffness region acting as a transitional zone for stress transmission. Alternatively, in other embodiments, the medium stiffness region can be omitted, and the high stiffness region can be placed directly adjacent to the low stiffness region.

[0051] As a further alternative, in other embodiments, the number and arrangement of regions with different stiffness can be changed. For example, more high / medium / low stiffness regions can be set, and the positional relationship between these regions can be changed to suit the application scenarios with different stress conditions.

[0052] Furthermore, the variable stiffness damping pads in Examples 1 and 2 are both molded from rubber material, with the main body being a single-layer rubber structure. As an alternative, in other embodiments, the main body can be a multi-layer structure, i.e., multiple rubber layers with a textile layer sandwiched between them, to improve overall tensile and flexural strength. Further, damping layers or other layer structures can be added to enhance overall performance. Additionally, the variable stiffness damping pads in Examples 1 and 2 are integral structures. As an alternative, in other embodiments, the variable stiffness damping pad can be a split structure formed by splicing and overlapping multiple damping pad blocks, as long as the spliced ​​damping pads also form areas with corresponding different stiffnesses.

Claims

1. A variable stiffness vibration damping pad, used in track laying, characterized in that, include: The main body is plate-shaped, with a long side dimension of 4.9m-6.1m and a short side dimension of 0.8m-2.3m. The variable stiffness damping pad has multiple regions with different stiffnesses. The plurality of regions with different stiffnesses include at least a low-stiffness region and a high-stiffness region with stiffness higher than that of the low-stiffness region. The low-stiffness zone is located in the middle of the width direction, and after being laid, it corresponds to the rail support area under the sleeper. The high-rigidity zone is located at both edges in the width direction, corresponding to the edge of the track bed slab after it is laid.

2. The variable stiffness vibration damping mat of claim 1, wherein, Also includes: The protrusion includes a plurality of protrusions disposed on the surface of the body and integrally formed therewith. The multiple protrusions are arranged in rows and columns, and the protrusions are of different sizes, thereby forming multiple regions with different stiffnesses.

3. The variable stiffness vibration damping pad according to claim 2, characterized in that: wherein, The different dimensions of the protrusions refer to different top surface dimensions of the protrusions and / or different spacing between the protrusions.

4. The variable stiffness vibration damping pad according to claim 3, characterized in that: wherein The different dimensions of the top surface of the protrusion are as follows: In the plurality of regions with different stiffness, the top surface dimension of the protrusion in the region with lower stiffness is smaller than the top surface dimension of the protrusion in the region with higher stiffness.

5. The variable stiffness vibration damping pad according to claim 4, characterized in that: wherein The protrusion is frustum-shaped. The top surface of the protrusion has a dimension of 10mm-22mm, and the bottom surface has a dimension of 40mm-60mm.

6. The variable stiffness vibration damping pad according to claim 5, characterized in that: wherein The frustum shape can be a circular frustum, an elliptical frustum, a polygonal frustum, or an irregular frustum.

7. The variable stiffness vibration damping pad according to claim 3, characterized in that: wherein The different spacing of the protrusions is as follows: In the plurality of regions with different stiffness, the spacing between the columns of protrusions in the region with lower stiffness is greater than the spacing between the columns of protrusions in the region with higher stiffness.

8. The variable stiffness vibration damping pad according to claim 7, characterized in that: wherein, The spacing between the protrusions in each column is 50mm-80mm.

9. The variable stiffness vibration damping pad according to claim 1, characterized in that, wherein, The variable stiffness damping pad is made of rubber. The rubber materials in regions with different stiffness have different ratios of raw rubber and filler content.

10. The variable stiffness vibration damping pad according to claim 1, characterized in that: wherein The multiple regions with different stiffnesses also include a medium-stiffness region with a stiffness between the low-stiffness region and the high-stiffness region. The medium stiffness region is located between the low stiffness region and the high stiffness region.

11. The variable stiffness vibration damping pad according to claim 10, characterized in that: in, The width of the low-stiffness zone is 3.5m-4.5m. The width of the medium stiffness zone is 0.25m-0.35m. The width of the high-rigidity region is 0.37m-0.47m.

12. The variable stiffness vibration damping pad according to claim 1, characterized in that: in, The main body is a single-piece structure, or The body contains a plurality of rubber layers and at least two fiber layers, and the fiber layers are sandwiched between the rubber layers.

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