Composite bushing and control arm

Abstract

The application discloses a composite bushing, and belongs to the technical field of automobile suspension systems, and relates to the technical scheme that the composite bushing comprises an outer tube, an inner tube and a rubber main spring, the inner tube is coaxially arranged in the outer tube, an elastomer I is formed by injection molding on the outer wall of the middle part of the inner tube, an elastomer II is formed by injection molding on the outer side of the elastomer I, the rigidity of the elastomer II is greater than that of the rubber main spring, the elastomer II is connected with the elastomer I and the inner tube, the elastomer II is arched towards the outer tube and the cross section is arc-shaped, the rubber main spring is filled between the inner tube and the outer tube, and the rubber main spring surrounds the elastomer II. The rubber main spring adhesively connects the outer tube, the inner tube and the elastomer II into a whole in a gapless matching state, small amplitude vibration is absorbed by the low-rigidity rubber main spring and the elastomer I, and the NVH performance of the vehicle is improved; when large amplitude sharp turning or braking occurs, the high-rigidity elastomer II shares the load, the radial rigidity is improved, the wheel positioning is maintained, and the driving comfort of the vehicle is ensured. The application further discloses a control arm.

Description

Technical Field

[0001] This invention belongs to the technical field of automotive suspension systems, and specifically relates to a composite bushing and control arm. Background Technology

[0002] Rubber bushings are a crucial component of automotive suspension. They are typically used to connect the suspension to the subframe, primarily for vibration damping, ensuring suspension compliance, and sound insulation. They transmit and withstand forces and torques in all directions, ensuring smooth and stable driving.

[0003] For example, Chinese patent CN205668479U discloses an upper connecting rod rubber bushing, comprising an outer skeleton, an inner skeleton, and a rubber component. The outer skeleton, inner skeleton, and rubber component are integrally vulcanized. Both the outer skeleton and inner skeleton are cylindrical tube structures, with the diameter of the outer skeleton being larger than that of the inner skeleton. The outer skeleton is fitted over the middle of the inner skeleton. Both the inner and outer skeletons are made of aluminum, and the inner and outer skeletons are connected by the rubber component. The upper and lower sidewalls of the rubber component are both concave inward. This type of bushing has tear resistance and durability, and the rubber component can withstand shear forces. However, its axial stiffness is limited, making it difficult to meet the impact requirements of the suspension control arm in the radial and axial directions.

[0004] Therefore, one applicant has developed a bushing for increasing axial stiffness (publication number CN202545578U), which includes a cylindrical shell with a cylindrical inner core having a spherical protrusion in the middle. An integrally vulcanized rubber layer separates the cylindrical shell and the inner core. This bushing is vulcanized in a mold from the cylindrical shell, inner core, and rubber together. After molding, the cylindrical shell is locked and riveted, increasing the product's axial stiffness and meeting the impact requirements of the suspension control arm in the axial direction.

[0005] The aforementioned suspension bushings need to withstand static and dynamic loads during use. The dynamic loads include radial, axial, and torsional loads. The spherical protrusion in the center of the inner core sacrifices the thickness of the rubber layer between the cylindrical shell and the spherical protrusion. Although this satisfies the axial stiffness of the bushing and makes the inner core less prone to axial movement, it reduces the energy absorption effect of the rubber layer to a certain extent, resulting in insufficient vibration damping, excessive shaking, and reduced vehicle driving comfort. If the volume of the spherical protrusion is reduced, its axial stiffness will also be reduced. Therefore, the existing rubber bushings urgently need improvement. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems in the prior art by proposing a composite bushing. The first technical problem to be solved by this invention is: how to improve driving comfort while ensuring the axial stiffness of the bushing.

[0007] The purpose of this invention is to address the aforementioned problems in the prior art by proposing a control arm. The second technical problem to be solved by this invention is: how to improve the axial stiffness and driving comfort of the control arm inner bushing.

[0008] The first technical objective of this invention can be achieved through the following technical solution: A composite bushing includes an outer tube, an inner tube, and a rubber main spring. The inner tube is coaxially disposed inside the outer tube. An elastomer I is injection-molded on the outer wall of the middle part of the inner tube, and an elastomer II is injection-molded on the outer side of the elastomer I. The stiffness of the elastomer II is greater than that of the rubber main spring. The elastomer II is connected to both the elastomer I and the inner tube. The elastomer II arches towards the outer tube and has an arc-shaped cross-section. The rubber main spring fills the space between the inner tube and the outer tube and surrounds the elastomer II.

[0009] Through the above technical solution, the high-rigidity elastomer II is directly used as the support and energy-absorbing component between the outer tube and the inner tube. The elastomer I and the rubber main spring wrap the elastomer II. The three components of the elastomer II, elastomer I and the rubber main spring can absorb the static load and dynamic load of the vehicle, ensuring the energy absorption effect and vibration attenuation. The arc-shaped arched part can suppress the axial movement of the inner tube and also ensure the axial stiffness of the composite bushing.

[0010] In the aforementioned composite bushing, the cross-section of the first elastomer is arc-shaped, and the second elastomer completely covers the first elastomer.

[0011] In the above-mentioned composite bushing, the cross-section of the first elastic body is arc-shaped, and the first elastic body is provided with connecting feet extending towards the outer tube. The second elastic body has pre-drilled holes spaced apart, and the connecting feet pass through the pre-drilled holes and are connected to the rubber main spring.

[0012] In the aforementioned composite bushing, the outer wall of the inner tube is provided with at least two mounting grooves, and each of the two mounting grooves is provided with a spring piece 1. Each of the two spring pieces 1 is inclined toward the outer end of the inner tube, and the two ends of the elastic body 2 are respectively connected to the two spring pieces 1.

[0013] In the aforementioned composite bushing, the outer wall of the inner tube is provided with at least one positioning rib, the positioning rib being located between the two spring sheets and being covered by the elastic body.

[0014] In the aforementioned composite bushing, the rubber main spring and elastomer one are both made of synthetic rubber, while elastomer two is made of long glass fiber reinforced TPU.

[0015] In the aforementioned composite bushing, positioning grooves are provided on the inner walls at both ends of the outer tube, and these positioning grooves are filled by the rubber main spring.

[0016] In the composite bushing described above, several protrusions are spaced apart at the opening of the positioning groove, and the gaps between the protrusions are filled by the rubber main spring.

[0017] In the aforementioned composite bushing, each of the two positioning grooves is provided with a second spring piece, both of the second spring pieces are inclined toward the outer end of the outer tube, the second spring piece has a notch, and the two second spring pieces are surrounded by the rubber main spring.

[0018] The second technical objective of this invention can be achieved through the following technical solution: A control arm includes a swing arm and the aforementioned composite bushing, wherein the swing arm has an assembly hole for mounting the composite bushing.

[0019] In summary, the advantages of this invention compared to the prior art are as follows: The rubber main spring bonds the outer tube, inner tube, and elastomer II into a seamless, integrated unit. Small vibrations are absorbed by the low-stiffness rubber main spring and elastomer I, improving the vehicle's NVH performance. During sharp turns or braking, the high-stiffness elastomer II shares the load, increasing radial stiffness, maintaining wheel alignment, and ensuring driving comfort. The TPU (thermoplastic polyurethane) elastomer II is compressed under extreme conditions, preventing direct impact between the inner tube metal and the outer tube, while also providing progressive damping. In other words, the thickness of the rubber main spring is sufficient to ensure the energy absorption effect between the outer and inner tubes, significantly increasing the upper limit of the load that this bushing can bear and enhancing the vibration damping effect; the second elastomer mainly bears the compressive load between the outer and inner tubes and maintains the radial stiffness of this bushing according to its own material, avoiding the problems of slow vehicle response and poor swing arm following caused by insufficient radial stiffness of the bushing; at the same time, the rubber elastomer one can support the second elastomer and ensure the normal deformation of the second elastomer. When the inner tube swings relative to the outer tube, the arc-shaped arch of the second elastomer can also ensure the axial stiffness of this bushing, thereby reducing the swing of the inner tube and thus improving the driving experience of the vehicle.

[0020] When the inner tube moves axially along its length, the inner tube and the second elastic body together cause the rubber main spring to deform. The first and second spring plates further suppress the deformation amplitude of the rubber main spring, thus ensuring the axial stiffness of the bushing. The positioning groove not only improves the bonding strength between the rubber main spring and the outer tube, but also helps to suppress the axial movement of the rubber main spring, thereby further ensuring the axial stiffness of the bushing. Furthermore, this bushing uses rubber main springs of different materials and stiffnesses, along with the second elastic body, as buffer components. By simply changing the thickness of the second elastic body, the overall radial stiffness and damping performance of the bushing can be altered. This makes subsequent adjustments to the bushing's performance easier and less costly, thereby improving the bushing's applicability to different vehicles.

[0021] The connecting foot passes through the reserved hole and is circumferentially limited by the reserved hole. After the connecting foot is combined with the rubber main spring, the connecting foot can improve the integrity of the rubber main spring, elastomer two, and elastomer one, making the finished product more robust. The outer side of the rubber main spring is fixed by the outer tube and the positioning groove, and the inner side of the rubber main spring is anchored by the inner tube, the outer wall of elastomer two, and the connecting foot. When the inner tube is twisted relative to the outer tube, the rubber main spring deforms and absorbs energy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the external structure of an embodiment; Figure 2 for Figure 1 One of the cross-sectional schematic diagrams; Figure 3 for Figure 1 An explosion diagram; Figure 4 This is a partial cross-sectional schematic diagram of an embodiment; Figure 5 This is a schematic diagram of the inner tube structure in the embodiment; Figure 6 for Figure 1 The second sectional view; Figure 7 This is another structural schematic diagram of an embodiment; Figure 8 A schematic diagram of the structure after adding the second spring in the embodiment; Figure 9 This is a cross-sectional view of the outer casing in the embodiment; Figure 10 An exploded view of the composite bushing and the swing arm; Figure 11 This is a schematic diagram of the swing arm structure in the embodiment.

[0023] Reference numerals: 100, outer tube; 110, positioning groove; 111, protrusion; 120, spring piece two; 121, notch two; 200. Inner tube; 210. Mounting groove; 211. Spring clip one; 212. Notch one; 220. Positioning rib; 300. Rubber main spring; 310. Deformation groove; 400. Elastomer 1; 410. Connecting foot; 500, Elastomer II; 510, Pre-drilled hole; 600, swing arm; 610, assembly hole. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0025] A composite bushing, such as Figures 1-9 As shown, the device includes an outer tube 100, an inner tube 200, and a rubber main spring 300. The inner tube 200 is coaxially disposed inside the outer tube 100. An elastomer 400 is injection molded on the outer wall of the middle part of the inner tube 200. An elastomer 500 is injection molded on the outside of the elastomer 400. The stiffness of the elastomer 500 is greater than that of the rubber main spring 300 and the elastomer 400. The elastomer 500 is connected to both the elastomer 400 and the inner tube 200. The elastomer 500 arches towards the outer tube 100 and has an arc-shaped cross-section. The rubber main spring 300 fills the space between the inner tube 200 and the outer tube 100. The outer side of the elastomer 500 is surrounded by the rubber main spring 300.

[0026] like Figures 2-6 As shown, the cross-section of elastomer 400 is arc-shaped, and the outer wall of elastomer 400 is fitted to the inner side of elastomer 500. The outer wall of elastomer 400 is provided with connecting feet 410 extending towards the outer tube 100. Pre-drilled holes 510 are spaced apart on elastomer 500. The connecting feet 410 pass through the pre-drilled holes 510 and are thermally bonded to the rubber main spring 300. In this embodiment, at least two connecting feet 410 are provided, and the number of pre-drilled holes 510 corresponds one-to-one with the number of connecting feet 410.

[0027] like Figure 7 As shown, in at least one embodiment, the cross-section of the first elastomer 400 is arc-shaped, and the second elastomer 500 completely covers the first elastomer 400, thereby omitting the connecting foot 410.

[0028] The outer wall of the inner tube 200 is provided with at least two mounting grooves 210. Each mounting groove 210 is provided with a spring piece 211. The spring piece 211 has elastic deformation properties. The two spring pieces 211 are inclined towards the outer end of the inner tube 200. The two ends of the elastic body 500 are respectively bonded to the end faces of the two spring pieces 211. The spring piece 211 has a notch 212 for radial expansion and contraction, so that the end of the inner tube 200 can open the spring piece 211, so that the spring piece 211 can slide into the mounting groove 210, reducing the processing difficulty of the inner tube 200.

[0029] First, an elastomer 400 and a connecting foot 410 are injection molded on the outer wall of the inner tube 200. Then, two spring pieces 211 are respectively inserted into the corresponding mounting slots 210. The inner tube 200 is placed in the mold and an elastomer 500 is injection molded, so that the inner tube 200, elastomer 400, elastomer 500, and two spring pieces 211 are a whole component for subsequent production. Finally, flowing rubber is injected between the inner tube 200 and the outer tube 100. The cooled rubber becomes the rubber main spring 300. The inner side of the rubber main spring 300 is bonded to the inner tube 200, the elastomer 500, and the connecting foot 410, and the outer side of the rubber main spring 300 is bonded to the inner wall of the outer tube 100.

[0030] like Figure 2 , Figure 4 , Figure 5 As shown, further, the outer wall of the inner tube 200 is provided with at least one positioning rib 220. The positioning rib 220 is located between the two elastic pieces 211 and is covered by the elastic body 400. The positioning rib 220 is used to ensure the injection molding firmness of the elastic body 400 and the inner tube 200.

[0031] The rubber main spring 300 and elastomer 400 are both made of synthetic rubber (a mixture of natural rubber and butadiene rubber), while elastomer 500 is made of long glass fiber reinforced TPU (a composite material of long glass fiber (LGF) and thermoplastic polyurethane (TPU)). The inner wall of the outer tube 100, the connecting foot 410, the elastomer 500, and the outer wall of the inner tube 200 are all coated with adhesive, such as a rubber adhesive like Chemlock 205 (CH205), to improve the connection between the rubber main spring and the outer tube 100, connecting foot 410, elastomer 500, and inner tube 200. Both ends of the rubber main spring 300 are provided with deformation grooves 310, which provide space for the rubber main spring 300 to twist and yaw, while also preventing stress concentration that could lead to fatigue damage.

[0032] like Figures 1-6 As shown, positioning grooves 110 are provided on the inner walls of both ends of the outer tube 100. The positioning grooves 110 are filled with rubber main springs 300 and are used to anchor the rubber main springs 300, thereby ensuring the bonding strength between the rubber main springs 300 and the outer tube 100. At the same time, they can also help suppress the axial movement of the rubber main springs 300, thereby further ensuring the axial stiffness of this bushing.

[0033] Furthermore, the positioning groove 110 has several protrusions 111 spaced apart at the opening, and the gaps between the protrusions 111 are filled by the rubber main spring 300 to enhance the bonding strength between the rubber main spring 300 and the positioning groove 110.

[0034] like Figure 8 , Figure 9 As shown, in some embodiments, each of the two positioning grooves 110 is provided with a second spring piece 120. Both second spring pieces 120 are inclined toward the outer end of the outer tube 100. The second spring piece 120 has a notch 121, which allows the second spring piece 120 to elastically deform. The second spring piece 120 abuts against the side wall of the positioning groove 110. The two second spring pieces 120 are surrounded by a rubber main spring 300.

[0035] The working principle of this invention is as follows: The rubber main spring 300 bonds the outer tube 100, inner tube 200, and elastomer 2 500 into a seamless whole. Small vibrations are absorbed by the low-stiffness rubber main spring 300 and elastomer 1 400. The combined thickness of the rubber main spring 300 and elastomer 1 400 is sufficient to ensure the energy absorption effect between the outer tube 100 and inner tube 200, significantly improving the upper limit of the load-bearing capacity of the rubber bushing, enhancing the vibration damping effect, and improving the NVH performance of the vehicle. The rubber elastomer 1 400 can support elastomer 2 500 without affecting the normal deformation of elastomer 2 500. When the inner tube 200 wobbles relative to the outer tube 100, the arc-shaped arch of elastomer 2 500 can also ensure the axial stiffness of the bushing, thereby reducing the wobble of the inner tube 200. When the inner tube 200 twists relative to the outer tube 100, the rubber main spring 300 deforms and absorbs the energy. During sharp turns or braking, the high-stiffness elastomer 2500 shares the compressive load between the outer tube 100 and the inner tube 200. The TPU elastomer 2500 is compressed under extreme conditions, providing progressive damping to improve the driving comfort of the vehicle.

[0036] When the inner tube 200 moves axially along its length, the inner tube 200, elastomer 200, and elastomer 400 together drive the deformation of the rubber main spring 300. Spring plates 211 and 120 further suppress the deformation amplitude of the rubber main spring 300, thus ensuring the axial stiffness of the bushing. Furthermore, the injection molding of elastomer 200 bonds the inner tube 200, elastomer 400, and spring plate 211 together. When elastomer 200 is subjected to ultimate compressive load, it can push spring plate 211 and elastomer 400 to deform, preventing elastomer 200 from exceeding the predetermined deformation amplitude and being damaged. This bushing uses a synthetic rubber main spring 300 and elastomer 400, and a long glass fiber reinforced TPU elastomer 500 as a buffer component. By simply changing the thickness of elastomer 500, the overall radial stiffness and damping performance of the bushing can be changed, making it easier to adjust the bushing's performance later, so that this bushing can be used in various vehicle suspensions.

[0037] Connecting foot 410 passes through reserved hole 510 and is circumferentially limited by reserved hole 510. After connecting foot 410 is combined with rubber main spring 300, connecting foot 410 can improve the integrity of rubber main spring 300, elastomer 1 400 and elastomer 2 500, making the finished product more robust and ensuring its service life.

[0038] A control arm, such as Figures 10-11 As shown, this control arm includes a swing arm 600 and the aforementioned composite bushing. The swing arm 600 has mounting holes 610 for installing the composite bushing. The composite bushing has sufficient axial stiffness and significantly improves driving comfort.

[0039] The specific embodiments described herein are merely illustrative of the spirit of the invention; those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, but without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A composite bushing, characterized in that: The device includes an outer tube (100), an inner tube (200), and a rubber main spring (300). The inner tube (200) is coaxially disposed inside the outer tube (100). An elastomer 1 (400) is injection molded on the outer wall of the middle part of the inner tube (200). An elastomer 2 (500) is injection molded on the outer side of the elastomer 1 (400). The stiffness of the elastomer 2 (500) is greater than that of the rubber main spring (300). The elastomer 2 (500) is connected to both the elastomer 1 (400) and the inner tube (200). The elastomer 2 (500) arches towards the outer tube (100) and has an arc-shaped cross-section. The rubber main spring (300) fills the space between the inner tube (200) and the outer tube (100) and surrounds the elastomer 2 (500).

2. The composite bushing according to claim 1, characterized in that: The cross-section of the first elastomer (400) is arc-shaped, and the second elastomer (500) completely covers the first elastomer (400).

3. The composite bushing according to claim 1, characterized in that: The cross-section of the first elastic body (400) is arc-shaped. The first elastic body (400) is provided with a connecting foot (410) extending towards the outer tube (100). The second elastic body (500) is provided with reserved holes (510) spaced apart. The connecting foot (410) passes through the reserved hole (510) and is connected to the rubber main spring (300).

4. The composite bushing according to any one of claims 2-3, characterized in that: The outer wall of the inner tube (200) is provided with at least two mounting grooves (210), and each of the two mounting grooves (210) is provided with a spring piece (211). Each of the two spring pieces (211) is inclined toward the outer end of the inner tube (200), and the two ends of the elastic body (500) are respectively connected to the two spring pieces (211).

5. The composite bushing according to claim 4, characterized in that: The outer wall of the inner tube (200) is provided with at least one positioning rib (220), the positioning rib (220) is located between the two elastic pieces (211), and the positioning rib (220) is covered by the elastic body (400).

6. The composite bushing according to claim 4, characterized in that: The rubber main spring (300) and elastomer one (400) are both made of synthetic rubber, while the elastomer two (500) is made of long glass fiber reinforced TPU.

7. The composite bushing according to claim 4, characterized in that: Positioning grooves (110) are provided on the inner walls at both ends of the outer tube (100), and the positioning grooves (110) are filled by the rubber main spring (300).

8. The composite bushing according to claim 7, characterized in that: The positioning groove (110) has a plurality of protrusions (111) spaced apart at the opening, and the gap between each of the protrusions (111) is filled by the rubber main spring (300).

9. The composite bushing according to claim 7, characterized in that: Both positioning grooves (110) are provided with spring sheet two (120), both spring sheet two (120) are inclined towards the outer end of the outer tube (100), each spring sheet two (120) has a notch two (121), and both spring sheet two (120) are surrounded by the rubber main spring (300).

10. A control arm, characterized in that: The control arm includes a swing arm (600) and a composite bushing according to any one of claims 1-9, wherein the swing arm (600) is provided with an assembly hole (610) for mounting the composite bushing.

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