Hybrid bellows for vehicle height adjustment devices

Abstract

We provide a hybrid bellows for vehicle height adjustment devices that has a long lifespan. [Solution] The present invention relates to a hybrid bellows for a vehicle height adjustment device, the hybrid bellows comprising a multilayer body 2 having a first free end 3, a second free end 4, and an operating chamber 5 that can be formed between the free ends 3 and 4, the body 2 having an inner elastomer layer 6 facing the operating chamber 5 and an outer elastomer layer 8 facing the surrounding environment 7, the inner elastomer layer 6 having a first material composition and the outer elastomer layer 8 having a second material composition. The hybrid bellows is characterized in that the first material composition and the second material composition are different from each other. Furthermore, the present invention relates to a vehicle height adjustment device comprising such a hybrid bellows.

Description

Technical Field

[0001] The present invention relates to a hybrid bellows for a vehicle height adjustment device and a vehicle height adjustment device including such a hybrid bellows.

Background Art

[0002] Devices for adjusting the height or leveling of motor vehicles are used to vary the height of the vehicle or the driver's cab in an adjustable manner or to keep the height constant when the load varies. This height adaptation is achieved by changing the pressure in the hermetically sealed working chamber of the device, which pressure is varied by supplying a suitable working medium to the working chamber or discharging the working medium from the working chamber.

[0003] For this purpose, conventional devices have a bellows made of an elastomeric material that forms a working chamber together with a cover member and a rolling piston. Compressed air is often used as the working medium. For leveling, the bellows is wound up or unfolded by at least one roll fold along the outer surface of the rolling piston according to the pressure in the working chamber, thereby changing its height.

[0004] Bellows known from the prior art generally have a multilayer structure, and the central reinforcing layer is a single-layer or multi-layer rigid support layer embedded in an elastic matrix, and both of its surfaces, that is, the inner side facing the working chamber and the outer side facing the outside air, are respectively covered by elastomeric layers.

[0005] Such bellows are described, for example, in document EP4077517A1. However, since the working medium used there is compressed air, the conditions required for the inner elastomeric layer are substantially the same as the conditions required for the outer elastomeric layer. As a result, the elastomeric layers used there are both composed of the same rubber mixture.

Summary of the Invention

[0006] However, in bellows of fluid-operated systems, the working chamber is filled with a fluid medium rather than compressed air. Depending on the application, various media are used, such as water, glycol, oil, brake fluid, or mixtures of these substances. These fluid mediums apply a different degree of stress to the inside of the bellows than air, which can cause premature damage to the inner elastomer layer due to the early formation of cracks in the inner layer.

[0007] Therefore, the object of the present invention is to provide a hybrid bellows for vehicle height adjustment devices that improves upon the shortcomings of the prior art and has a longer lifespan than known solutions.

[0008] The main features of the present invention are described in claim 1. Further aspects of the present invention are described in claims 14 and 16. Specific embodiments of the present invention constitute the subject matter of claims 2 to 13, or claim 15.

[0009] According to the main claim, the above objective is achieved by a hybrid bellows for a vehicle height adjustment device. The hybrid bellows comprises a multilayer body having a first free end, a second free end, and an operating chamber formed or constructed between the free ends, the body having an inner elastomer layer facing the operating chamber and an outer elastomer layer facing the surrounding environment, the inner elastomer layer having a first material composition and the outer elastomer layer having a second material composition. The hybrid bellows is characterized in that the first material composition and the second material composition are different from each other. Therefore, the bellows are not of a "single type" with respect to the elastomer material used.

[0010] The term "operating chamber" is understood to refer to the region of the hybrid bellows located between the connection point of the first free end to the rolling piston and the connection point of the second free end to a cover member or the like, when the bellows is used for its intended purpose.

[0011] Hybrid bellows designed in this manner are particularly suitable for fluid-pressure acting systems because the inner and outer elastomer layers of the bellows can be optimally adapted to their respective contact media. The media in contact with the outer or inner layer of the bellows are referred to as the contact media. In the case of the outer layer, the contact media is typically air, while the contact media of the inner layer is, in particular, an incompressible fluid. As a result, the outer elastomer layer can be selected to give the layer specific resistance to ambient air. Furthermore, the material composition of the outer layer can be selected to withstand further environmental influences such as heat, cold, or ozone. The inner layer of the bellows can have a material composition that is particularly resistant to each fluid in the working chamber. In the context of this disclosure, the material composition of the inner layer is referred to as the "first material composition," and the material composition of the outer layer is referred to as the "second material composition." Because the first and second material compositions of the bellows are optimally adapted to their respective contact media, the risk of damage or wear of the hybrid bellows due to chemical degradation is minimized.

[0012] According to one embodiment, when a hybrid bellows is used in its intended application, the working chamber can be configured to be filled with fluid. The working chamber should be particularly liquid-tight. This prevents unintended leakage of fluid from the working chamber. At the same time, it also prevents unintended inflow of air from the external environment into the working chamber.

[0013] According to one embodiment, the fluid in the working chamber is selected from the group consisting of brake fluid, oil, particularly hydraulic oil, coolant, glycol, and mixtures of glycol and water. It is particularly advantageous that the selected fluid is one that is already used in a particular vehicle, provided that it does not increase the maintenance burden.

[0014] According to one embodiment, the second material composition can consist of an elastomer selected from the group consisting of natural rubber, polybutadiene rubber ("BR"), acrylonitrile butadiene rubber ("NBR"), hydrogenated acrylonitrile butadiene rubber, silicone, or ethylene propylene diene monomer rubber ("EPDM"). The above materials are characterized by particularly high resistance to oil and / or glycol-containing liquids. BR is characterized by high elasticity and very good low-temperature properties due to its low glass transition temperature. NBR has polar groups that interact minimally with non-polar liquids such as benzene, oil, and fat, so the material does not swell after contact with these media. EPDM can withstand temperatures up to 150°C. This material is also resistant to polar substances. Preferably, the first and second material compositions should be selected so that they can be designed to adhere to each other. When using an intermediate layer having a third material composition, the first and second material compositions should be selected so that they can be arranged to adhere to the third material composition, respectively.

[0015] According to one embodiment, the first material composition may include a chlorobutadiene rubber elastomer ("CR elastomer" or "CR elastomer"). CR elastomers are particularly robust against the effects of the external environment and are therefore suitable for use in the outer elastomer layer. In addition, because CR elastomers have a long track record of use in bellows, their properties can be easily predicted and / or simulated during the design phase.

[0016] According to one embodiment, the main body may have a reinforcing layer positioned between the inner elastomer layer and the outer elastomer layer. The reinforcing layer stabilizes the hybrid bellows. This ensures that the unreinforced seal bellows can withstand high pressure without undesirable deformation or breakage.

[0017] According to one embodiment, the reinforcing layer comprises an elastomer matrix and at least one rigid support layer, the at least one rigid support layer being at least partially embedded in the elastomer matrix. According to one development, the reinforcing layer can also be configured to have two rigid support layers, which are at least partially embedded in the elastomer matrix. The use of multiple rigid support layers has proven particularly suitable because, as a result, the reinforcing layer is lightweight while achieving high stability.

[0018] According to one embodiment, the elastomer matrix can also be configured to have a third material composition. According to one development, the third material composition can be substantially the same as the first material composition, or the third material composition can be substantially the same as the second material composition. As a result, the manufacture of the bellows is simplified because the same equipment, or at least the same parts of the equipment, used to manufacture the inner or outer elastomer layer can be used to manufacture the reinforcing layer elastomer. However, it is also conceivable that the third material composition is different from the first and second material compositions.

[0019] According to one embodiment, each rigid support layer can be configured to comprise a plurality of rigid support sections. According to one development, the rigid support sections can preferably be composed of polyamide and / or polyester fibers, yarns, or filaments, or polyamide and / or polyester fabrics. The use of such fiber reinforcements has proven particularly suitable because the hybrid bellows are lightweight yet highly stable, and their flexibility is limited to the flexibility of the fibers in the fiber direction. As a result, the bellows can be manufactured very simply and at low cost. In the context of this disclosure, the terms “fiber,” “yarn,” and “filament” are used synonymously unless otherwise consistent with the context. All of these terms refer to substantially elongated structures made of natural or synthetic materials, where natural fiber materials are derived from plants, animals, or minerals, and synthetic fiber materials include polymers in particular.

[0020] In another embodiment, the present invention relates to a height adjustment device for adjusting the height of a vehicle, comprising two hybrid bellows according to the disclosure. The height adjustment device also comprises a first wall member and a second wall member axially spaced from the first wall member, wherein the first wall member, the second wall member, and the hybrid bellows form an operating chamber. For this purpose, the free end of each hybrid bellows is fixed to the first wall member or the second wall member, for example, via a clamping ring. Such a height adjustment device is particularly long-lasting and thereby achieves high chemical resistance because the elastomer layer applied to the inner or outer reinforcing layer side can be adapted to the respective contact medium.

[0021] According to one embodiment, the height adjustment device can be a fluid pressure type height adjustment device. A hybrid bellows defines a pressurized working chamber, and the bellows forms a roll fold. Pressure changes in the working chamber result in volume changes, which in turn cause movement of the bellows in the roll fold, and as a result adjust the vertical position of the vehicle.

[0022] According to one embodiment, the height adjustment device is a base point adjustment device for a helical spring inside an automobile chassis.

[0023] In yet another aspect, the present invention relates to a system for adjusting the height of a vehicle, comprising a height adjustment device according to the present disclosure, a first spring support, a second spring support, and a spring disposed between the first spring support and the second spring support.

[0024] Other aspects, details, and advantages of the invention will become apparent from the following description of embodiments with reference to the wording of the claims and the drawings. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic cross-sectional view of the body of the hybrid bellows according to the first embodiment. [Figure 2] This is a schematic cross-sectional view of the body of a hybrid bellows according to the second embodiment. [Figure 3] It is a schematic cross-sectional view of the main body of the hybrid bellows according to the third embodiment. [Figure 4] It is a diagram showing a vehicle height adjustment system according to one possible embodiment. **[Embodiments for Carrying out the Invention]**

[0026] In the drawings, the same or corresponding members are given the same reference numerals respectively, and when not appropriate, they are not described repeatedly. Features that have already been described are not described repeatedly to avoid repetition, and can be applied to all members having the same reference numerals or corresponding reference numerals to each other unless explicitly excluded. The disclosure content included throughout this specification can be appropriately transferred to the same parts having the same reference numerals or the same component names. The position information selected in the detailed description, such as upper, lower, side, etc., refers to the directly described and shown drawings, and when the position is changed, it is appropriately applied to the new position. Furthermore, individual features or combinations of features from different exemplary embodiments shown and described can also represent independent, inventive, or solutions according to the present invention.

[0027] FIG. 1 shows a schematic cross-section of the main body 2 of a hybrid bellows 1 according to one possible embodiment. The main body 2 has a first free end 3 and a second free end 4, and these two free ends 3, 4 are each connected to, for example, a rolling piston and a cover member (both not shown), thereby forming an operating chamber 5. The main body includes an inner elastomer layer 6 facing the operating chamber 5 and an outer elastomer layer 8 facing the external environment 7. The operating chamber 5 is filled with a fluid 13.

[0028] The inner elastomer layer 6 has a first material composition, and the outer elastomer layer 8 has a second material composition different from the first material composition. In the illustrated example, the difference between the two material compositions is indicated by different hatching lines of the elastomer layers 6, 8.

[0029] A two-layer reinforcing layer 9 is also positioned between the inner elastomer layer 6 and the outer elastomer layer 8. Therefore, the reinforcing layer 9 shown in Figure 1 has two rigid support layers 11 embedded in a common elastomer matrix 10 of the reinforcing layer 9. Each rigid support layer 11 comprises a plurality of filamentous rigid support portions 12, preferably made from polyamide and / or polyester. In the illustrated example, the third material composition of the elastomer matrix 10 of the reinforcing layer 9 is substantially identical to the first material composition of the inner elastomer layer 6 and is indicated by similar hatching lines. As a result, the reinforcing layer 9 can be formed simultaneously with the inner elastomer layer 6 in the same process, thus simplifying the manufacture of the bellows 1.

[0030] Figure 2 is a schematic cross-sectional view of the main body 2 of the hybrid bellows 1 according to the second embodiment. The hybrid bellows 1 shown in Figure 2 differs from the hybrid bellows 1 in Figure 1 mainly in that the third material composition of the elastomer matrix 10 of the reinforcing layer 9 is substantially the same as the second material composition of the outer elastomer layer 8.

[0031] Figure 3 is a schematic cross-sectional view of the main body 2 of the hybrid bellows 1 according to the third embodiment. In the case of Figure 3, all three material compositions are different from each other. Therefore, the elastomer matrix 10 of the reinforcing layer 9 has a different material composition from the inner elastomer layer 6 and the outer elastomer layer 8, and the inner elastomer layer 6 and the outer elastomer layer 8 also have different material compositions from each other.

[0032] Figure 4 shows a vehicle height adjustment system 100 according to one possible embodiment. The system 100 dampens and mitigates the impact of the vehicle and performs leveling or height adjustment. To level the vehicle, the system includes a height adjustment device 14, which in the case of Figure 4 is a base point adjustment device. The height adjustment device 14 includes a first wall member 15 and a second wall member 16, spaced apart from each other along the longitudinal axis L. The wall members 15, 16 are connected via two hybrid bellows 1, which together with the bellows 1 enclose a variable fluid volume within the working chamber 5 by forming a roll fold 20. For this purpose, the free ends 3, 4 of the hybrid bellows are fixed to the first wall member 15 or the second wall member 16, respectively. The second wall member 16 also functions as a first spring support 17 for a spring 19. The system 100 shown in Figure 4 illustrates an intended use example of the hybrid bellows 1 described herein.

[0033] The longitudinal axis L passes through the system 100, and height adjustment is also performed in this direction. The system 100 includes a damper 23, which is a hydraulic damper in the illustrated example. The stopper cover member 21 is attached to the front of the hydraulic damper 23. The damper rod protrudes from the damper housing at the same front and is connected to an opposing support 18 which functions as a second spring support.

[0034] System 100 also includes a spring 19, which is a compression coil spring as shown in Figure 4. The spring is supported at a first end by a first spring support 17 and at a second spring support 18. In the illustrated example, the first spring support 17 is the upper surface of the second wall member 15, and the second spring support 18 is the opposing support 18. When a force is applied to the height adjustment device 14 in the direction of the opposing support 18, or when a force is applied to the opposing support 18 in the direction of the height adjustment device 14, the spring 19 is compressed. To prevent overloading or complete compression of the spring 19, system 100 also includes an elastic additional spring 22. The additional spring 22 is positioned between the height adjustment device 14 and the opposing support 18. Furthermore, the additional spring 22 faces the stopper cover member 21 along its longitudinal axis L. As a result, the additional spring 22 can press against the stopper cover member 21 and restrict the path of the spring.

[0035] When a load is applied to the vehicle, the spring 19 deflects along a path corresponding to the load, causing the vehicle to descend accordingly. This displacement can be offset by leveling by the height adjustment device 14. To return the vehicle to its original height before the load was applied, additional fluid 13 is injected into the working chamber 5 of the height adjustment device 14. This increases the volume of the working chamber 5, displacing the second wall member 16 of the height adjustment device 14 and the base point of the spring 19. The pre-pressurized spring 19 adjusts along its longitudinal axis L, pushing against the opposing support 18, thereby pushing the vehicle back to its original height.

[0036] The present invention is not limited to any of the embodiments described above and can be modified in various ways. To avoid duplication, features disclosed in relation to the apparatus are also applicable as features disclosed in relation to the method, and features disclosed in relation to the method are also applicable as features disclosed in relation to the apparatus.

[0037] All features and advantages described in the claims, specification, and drawings, including structural details, spatial arrangement, and method steps, may be essential to the present invention, individually or in very different combinations. [Explanation of symbols]

[0038] 1 Hybrid Bellows 2 Main unit 3 1st free end 4 Second free end 5. Working chamber 6. Inner elastomer layer 7. Surrounding Environment 8. Outer elastomer layer 9 Reinforcement layer 10 Elastomer Matrix 11 Rigid support layer 12 Rigid support part 13 Fluid 14 Height adjustment device 15. First wall member 16. Second wall member 17. First spring support section 18 Opposing support part 19 springs 20 roll folds 21 Stopper cover component 22 Additional springs 23 Damper 100 Systems L Long axis A-axis

Claims

1. A hybrid bellows (1) for a vehicle height adjustment device (14), comprising a multilayer body (2) having a first free end (3), a second free end (4), and an operating chamber (5) formed between these free ends (3, 4), wherein the body (2) has an inner elastomer layer (6) facing the operating chamber (5) and an outer elastomer layer (8) facing the surrounding environment (7), the inner elastomer layer (6) having a first material composition, the outer elastomer layer (8) having a second material composition, and the first and second material compositions being different from each other, the hybrid bellows (1).

2. The hybrid bellows (1) according to claim 1, wherein the working chamber (5) is filled with fluid (13) when used for its intended purpose.

3. The hybrid bellows (1) according to claim 2, wherein the fluid (13) in the working chamber (5) is selected from the group consisting of brake fluid, oil, particularly hydraulic oil, coolant, glycol, and a mixture of glycol and water.

4. The hybrid bellows (1) according to any one of claims 1 to 3, wherein the first material composition comprises an elastomer selected from the group consisting of natural rubber, polybutadiene rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, silicone, or ethylene propylene diene monomer rubber.

5. The hybrid bellows (1) according to any one of claims 1 to 4, wherein the second material composition comprises a chlorobutadiene rubber elastomer.

6. The hybrid bellows (1) according to any one of claims 1 to 5, wherein the main body (2) has a reinforcing layer (9) disposed between the inner elastomer layer (6) and the outer elastomer layer (8).

7. The hybrid bellows (1) according to claim 6, wherein the reinforcing layer (9) comprises an elastomer matrix (10) and at least one rigid support layer (11), and at least one rigid support layer (11) is at least partially embedded in the elastomer matrix (10).

8. The hybrid bellows (1) according to claim 7, wherein the reinforcing layer (9) has two rigid support layers (11) that are at least partially embedded in the elastomer matrix (10).

9. The hybrid bellows (1) according to claim 7 or claim 8, wherein the elastomer matrix (10) has a third material composition.

10. The hybrid bellows (1) according to claim 9, wherein the third material composition is substantially the same as the first material composition, or the third material composition is substantially the same as the second material composition.

11. The hybrid bellows (1) according to any one of claims 7 to 10, wherein each of the rigid support layers (11) includes a plurality of rigid support parts (12).

12. The hybrid bellows (1) according to claim 11, wherein the rigid support portion (12) is a fiber made of polyamide and / or polyester, or a woven fabric made of polyamide and / or polyester.

13. The hybrid bellows (1) according to any one of claims 1 to 12, wherein the working chamber (5) formed by the main body (2) has a liquid-tight structure.

14. A vehicle height adjustment device (14) comprising two hybrid bellows (1) according to any one of claims 1 to 13, a first wall member (15), and a second wall member (16) spaced axially apart from the first wall member (15), wherein the first wall member (15), the second wall member (16), and the two hybrid bellows (1) form an operating chamber (5).

15. The height adjustment device (14) according to claim 14, wherein the height adjustment device (14) is a fluid pressure operated height adjustment device (14).

16. A vehicle height adjustment system (100), comprising a height adjustment device (14) according to claim 14 or claim 15, a first spring support (17), a second spring support (18), and a spring (19) disposed between the first spring support (17) and the second spring support (18).

Images