Shock absorber and motor vehicle with active chassis

Abstract

The invention relates to a shock absorber (1) having a damping piston which can be moved back and forth in an axial direction relative to a main pipe having a hydraulic medium, the main pipe being arranged in a container pipe (5), an intermediate pipe being arranged between the main pipe and the container pipe (5), wherein the main pipe, the intermediate pipe and the container pipe (5) are coaxially arranged in a three-pipe damping structure (2), the damping piston is attached to the end of the piston rod, and the three-pipe damping structure (2) is equipped with a hydraulic end position damper and has a central valve block with two damper valve devices at the end thereof facing away from the piston rod. In order to improve the shock absorber (1) in terms of function and / or production technology, the central valve block is partially surrounded by an air spring which comprises an air spring housing surrounding the central valve block, and the three-pipe shock absorption structure (2) has a gas compensation volume at the end of the piston rod of the three-pipe shock absorption structure. And the gas compensation volume is arranged in an annular space between the intermediate tube and the container tube (5).

Description

Technical Field

[0001] The invention relates to a shock absorber having a shock absorbing piston which can be moved back and forth in an axial direction relative to the main pipe in a main pipe with a hydraulic medium, the main pipe being arranged in a container pipe, an intermediate pipe being arranged between the main pipe and the container pipe, wherein the main pipe, the intermediate pipe and the container pipe are coaxially arranged in a three-tube shock absorbing structure, wherein the shock absorbing piston is attached to the end of a piston rod, the three-tube shock absorbing structure is equipped with a hydraulic end position damping element and has a central valve block with two shock absorber valve devices at its end facing away from the piston rod. Background Art

[0002] German patent publication DE 10 2019 104 714 A1 discloses a motor vehicle shock absorber with an air spring unit, wherein a working space filled with compressed air surrounds a valve seat. German patent publication DE 10 2013 212 974 A1 discloses a motor vehicle shock absorber with an air spring unit, wherein the working space surrounds the valve seat. German patent publication DE 10 2013 11 3 737 A1 discloses a motor vehicle shock absorber with an air spring unit, wherein the switching valve is almost completely arranged in the switching volume of the chamber defining the air spring unit. German patent publication DE 197 53 637 A1 discloses a motor vehicle shock absorber with an air spring unit, wherein the residual pressure valve is arranged in the air spring piston. German patent publication DE 100 14 467 C1 discloses a motor vehicle shock absorber with an air spring unit, wherein an unwinding piston surrounds the housing of the variable damping device. Summary of the invention

[0003] The object of the invention is to improve a shock absorber according to the preamble of claim 1 with regard to function and / or production technology.

[0004] This problem is solved in a shock absorber having a damping piston which can be moved back and forth in an axial direction relative to the main pipe with a hydraulic medium, wherein the main pipe is arranged in a container pipe, an intermediate pipe is arranged between the main pipe and the container pipe, the main pipe, the intermediate pipe and the container pipe are arranged coaxially in a three-tube damping arrangement, the damping piston is attached to the end of the piston rod, wherein the three-tube damping arrangement is equipped with a hydraulic end position damping element and has a central valve block with two damper valve devices at its end facing away from the piston rod, wherein the central valve block is partially surrounded by an air spring, which includes an air spring housing surrounding the central valve block, wherein the three-tube damping arrangement has a gas compensation volume at its piston rod end, which is arranged in the annular space between the intermediate pipe and the container pipe. In one aspect, this provides a shock absorber or vibration damper which enables a motor vehicle equipped with the shock absorber or vibration damper to run very comfortably both at high and low frequencies. This provides an ingenious solution to the installation space conflicts caused by the combination of the gas compensation volume and the air spring on the three-tube shock absorber structure. At the piston end of the three-tube shock absorber structure, the annular space between the intermediate tube and the container tube is effectively used to accommodate the gas compensation volume. The gas compensation volume is advantageously shown as having an air bag for accommodating a gas such as air. The air bag is formed by an airtight flexible material. The air bag is located between the intermediate tube and the container tube and is connected to the bayonet valve. During operation of the shock absorber, the air bag provides separation of oil and gas. In addition, the air bag prevents oil foaming. At the end of the three-tube shock absorber structure facing away from the piston rod, by partially surrounding the central valve block with an air spring, a sufficiently large air volume can be provided for the air spring in a particularly advantageous manner. The resulting disadvantages in the connection of the hydraulic line to the central valve block are acceptable after weighing. In each case, the two shock absorber valve devices advantageously include a check valve. One of the shock absorber valve devices also includes a rebound valve. In addition to the check valve, the other shock absorber valve device advantageously also includes a pressure step valve. The air spring housing surrounding the central valve block allows the air spring chamber represented by the air spring to be maximized very effectively. This results in significant packaging advantages. In addition, the air spring can have a softer design because a larger volume can be provided in the air spring housing compared to conventional shock absorbers.

[0005] A preferred exemplary embodiment of the shock absorber is characterized in that the air spring housing comprises an upper housing part which surrounds the container tube on the outside. The upper housing part advantageously surrounds the lower end region of the container tube. The multi-part design of the air spring housing simplifies the production and assembly of the air spring.

[0006] Another preferred exemplary embodiment of the shock absorber is characterized in that the three-tube shock absorber structure comprises a bellows which surrounds the outside of the container tube above the housing upper part. The bellows is advantageously used to realize the movement of the shock absorber caused by operation in the installed state and during operation.

[0007] Another preferred exemplary embodiment of the shock absorber is characterized in that the housing top part is polygonal on the outside. The available installation space can thus be optimally utilized. The air spring housing with the housing top part and the housing bottom part is advantageously manufactured as an injection molded part from a suitable plastic material.

[0008] Another preferred exemplary embodiment of the shock absorber is characterized in that the air spring housing comprises a housing lower part which surrounds the container tube on the outside. The housing lower part is preferably detachably connected to the housing upper part of the air spring housing, for example by a snap-on or latching connection. This further simplifies the production and assembly of the air spring housing.

[0009] Another preferred exemplary embodiment of the shock absorber is characterized in that the housing lower part is polygonal on the outside. This also proves to be advantageous in terms of the use of the available installation space.

[0010] Another preferred exemplary embodiment of the shock absorber is characterized in that the housing lower part has at least one recess for the shock absorber valve block on the central valve block. A free end of the shock absorber valve block preferably protrudes outwards beyond the housing lower part. This ensures that the shock absorber valve block can be accessed from the outside.

[0011] Another preferred exemplary embodiment of the shock absorber is characterized in that the housing lower part has at least one recess for connecting the valve block on the central valve block. This enables the hydraulic line to be connected to the central valve block even when the air spring is installed.

[0012] The invention also relates to a motor vehicle with an active chassis comprising at least one of the aforementioned shock absorbers. The motor vehicle with the active chassis advantageously comprises four wheels, to which in each case one of the aforementioned shock absorbers is associated.

[0013] The present invention also relates to a container tube, an intermediate tube, a main tube, a central valve block, an air spring housing, in particular a housing upper part and / or a housing lower part, for the aforementioned shock absorber. The above parts can be purchased separately. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Further advantages, features and details of the invention emerge from the following description, in which various exemplary embodiments of the invention are described in detail with reference to the attached drawings. The drawings show:

[0015] Figure 1 A perspective view of a buffer strut having a three-tube shock absorbing structure is shown;

[0016] Figure 2 A schematic cross section is shown Figure 1 Three-tube shock-absorbing structure;

[0017] Figure 3 The longitudinal section view shows Figure 1 A three-tube shock absorbing structure, wherein the container tube of the three-tube shock absorbing structure is not shown in cross section;

[0018] Figure 4 shows a perspective view of a shock absorber having a three-tube shock absorber structure which is surrounded by an air spring at one end facing the front axle;

[0019] Figure 5 A shock absorber having a triple-tube shock-absorbing structure associated with a rear axle of a motor vehicle is shown. DETAILED DESCRIPTION

[0020] Figures 1 to 3 A damper strut 10 with a spring fork 11 is shown in different views. The damper strut 10 comprises a shock absorber 1 , also called a vibration absorber. The shock absorber 1 is designed as a three-tube shock-absorbing structure 2 with a main tube 3 , a middle tube 4 and a reservoir tube 5 .

[0021] The shock absorber 10 with the shock absorber 1 designed as a three-tube shock absorber structure 2 is part of a hydraulic system which is used in a motor vehicle as an active shock absorber control during operation of the motor vehicle. The motor vehicle preferably comprises four wheels, each of which is associated with a shock absorber 1 designed as a three-tube shock absorber structure 2. The three-tube shock absorber structure or shock absorber is also referred to as shock absorber for short. The hydraulic shock absorber represents a shock absorber in the active chassis of a motor vehicle.

[0022] The three-tube shock absorber arrangement 2 is operated with a hydraulic medium. The hydraulic medium is preferably a hydraulic fluid, which is also called hydraulic oil or simply “oil”. In addition to the hydraulic shock absorber volume, the hydraulic shock absorber comprises a gas compensation volume 21 .

[0023] The active damping control comprises a hydraulic actuator device which is hydraulically connected to the shock absorber via a hydraulic line. The hydraulic actuator device in the active chassis of the motor vehicle serves to activate or drive the hydraulic shock absorber in a targeted manner. To this end, the hydraulic actuator device advantageously comprises an independent hydraulic pump for each shock absorber. Two hydraulic pumps can be combined together in each axle of the motor vehicle to form an electric pump unit. The hydraulic pumps associated with the respective axle are advantageously individually controllable via a common control unit.

[0024] In the main pipe 3 of the three-tube shock absorbing structure 2, Figure 2 The damping piston 6 in the damping device can move up and down. The piston rod 7 extends from the damping piston 6. Figure 2 In the embodiment, the damping piston extends upwardly out of the three-tube damping structure 2 through the sealing guide unit 32. The upper end of the piston rod 7 ( Figure 2 ) connected to a supporting structure of a motor vehicle.

[0025] The main pipe 3, the intermediate pipe 4 and the container pipe 5 are arranged coaxially and are provided with a gap in the radial direction. The annular space between the main pipe 3 and the intermediate pipe 4 allows the hydraulic medium to pass downwards, in particular the return line of the hydraulic medium, without the need for an additional hydraulic line. The annular space between the intermediate pipe 4 and the container pipe 5 is advantageously used to accommodate the gas compensation volume 21.

[0026] The gas compensation volume 21 is shown with a gas bag 22 which is received at the end of the piston rod of the three-tube shock absorbing structure 2, namely at Figure 2 , between the intermediate tube 4 and the container tube 5. Radially, within the gas compensation volume 21, the piston rod 7 in the main tube 3 is surrounded by a hydraulic end position damping element 19 with a hydraulic pull stop 39.

[0027] exist Figure 2 In the embodiment of the present invention, the three-tube shock-absorbing structure 2 is equipped with a central valve block 12 at its lower end. Two shock absorber valve devices 8 and 9 are integrated in the central valve block 12. In each case, the shock absorber valve devices 8 and 9 include non-return valves.

[0028] Furthermore, the shock absorber valve device 8 comprises a rebound valve which is hydraulically connected to the annular space between the main pipe 3 and the intermediate pipe 4 via the annular gap 71. Figure 2 In the embodiment, the main pipe 3 is connected via a relatively large central through hole 72 to a pressure step valve in the shock absorber valve device 9 at the bottom.

[0029] The central valve block 12 includes a base block 13, which is constructed as a complete tube, for example. The outside of the base block 13 has the shape of a right cylindrical shell, for example. For example, the base block 13 is constructed as a milled part and attached to the lower end of the three-tube shock absorbing structure 2.

[0030] The central valve block 12 also includes two shock absorber valve blocks 16, 17, which are essentially of right cylindrical design. The two shock absorber valve blocks 16, 17 can be connected integrally to the base block 13. The shock absorber valve blocks 16, 17 are used to receive and / or represent the shock absorber valve devices 8 and 9. The two shock absorber valve blocks 16, 17 are arranged coaxially to each other and transversely to the longitudinal axis of the three-tube shock absorbing structure 2.

[0031] The central valve block 12 further includes a connecting valve block 18. The connecting valve block 18 is constructed as a separate component and is attached to the base block 13. For example, two screws 73, 74 are used to attach the connecting valve block 18 to the base block 13 of the central valve block 12.

[0032] Designing the connecting valve block 18 as a separate component has the advantage, in particular, that a packaging-related design of the shock absorber can be achieved with relatively little design effort, in particular when installed in different motor vehicle variants or motor vehicle retrofits. In addition, the separate connecting valve block 18 can be designed and arranged on the base block 13 so that the specific crash requirements of the motor vehicle equipped with the shock absorber 1 can be perfectly met.

[0033] Regarding the packaging-related design of the connecting valve block 18, the positioning of the hydraulic connectors 23, 24 is particularly important. The hydraulic connectors 23, 24 at the connecting valve block 18 are used to connect hydraulic lines 27, 28, especially as Figure 4 and Figure 5 It can be seen that the three-tube shock absorbing structure 2 can be actively hydraulically controlled via hydraulic lines 27 and 28. To this end, the hydraulic lines 27 and 28 are hydraulically connected to the Figure 4 The active damping control element 29 is represented only by a rectangle.

[0034] Figure 4 and Figure 5 It is shown in perspective how a three-tube shock-absorbing structure 2 with a central valve block 12 at its lower end can be designed to fit into an installation space, in particular when installed in a motor vehicle 30 with an active chassis 31 .

[0035] exist Figure 4 and Figure 5 Only with the help of Figure 4 The various components 43 to 46 and Figure 5 The individual components 47 to 49, 53 to 56 in the motor vehicle 30 are shown, which places high demands on the designer, especially because the hoses and lines, especially the hydraulic lines 27, 28, need to be sufficiently spaced from the surrounding components during the operation of the motor vehicle 30 and throughout the entire spring and steering stroke. In addition, the bending radii and stretching lengths that occur must be observed.

[0036] For example, Figure 3 It can be seen that the shock absorber 1 configured as a three-tube shock absorbing structure 2 combined with the air spring 20 leads to additional design work. The air spring 20 is advantageously configured and arranged so that the air spring 20 surrounds the central valve block 12 from the lower end of the three-tube shock absorbing structure 2. In one aspect, this maximizes the air spring space that can be represented by the air spring 20. Due to the larger volume, the air spring 20 can be advantageously designed to be softer. In addition, the design and arrangement of the air spring 20 on and around the central valve block 12 creates packaging advantages.

[0037] The air spring 20 comprises an air spring housing 50 having a housing top 51 and a housing bottom 52. The air spring housing 50 comprises a single relatively large air volume. The air spring housing 50 extends around the lower end of the three-tube damping structure 2 having the central valve block 12. In the axial direction, the air spring housing 50 is arranged between the bellows 58 and the central valve block 12, which is partially surrounded by the housing bottom 52.

[0038] The air spring housing 50 rests with its housing lower part 52 on the axial support ring 15, which is attached to the lower end of the three-tube damping structure 2. The axial support ring 15 is combined with an adapter body 14, which allows the air spring housing 50 to be attached on the outside to the container tube 5 of the three-tube damping structure 2. The air spring housing 50 is attached to the adapter body 14, for example by a snap-on or latching connection.

[0039] Figure 4 It is shown how the air spring housing 50 of the air spring 20 surrounds the central valve block 12, so that the connecting valve block 18 remains free. Figure 4 In the embodiment, the three-tube shock-absorbing structure 2 is associated with the front axle of the motor vehicle 30. Component 43 is the brake air supply. Component 44 is the lower transverse link. Component 45 is the tie rod. Component 46 is the cardan shaft.

[0040] Figure 4 It is shown how the air spring volume of the air spring 20 extends around the connecting valve block 18. Therefore, the maximum air spring volume can be represented by the air spring housing 50. In addition, Figure 4 The connecting valve block 18 is shown to be designed so that, on the one hand, the connection of the hydraulic lines 27, 28 to the central valve block 12 is simplified. Furthermore, even when the air spring 20 is installed, the shutoff screws 41, 42 of the shutoff valves 25, 26 integrated in the connecting valve block 18 remain accessible.

[0041] exist Figure 5 In the embodiment of the invention, the three-tube shock-absorbing structure 2 is associated with the rear axle of a motor vehicle 30. Component 47 is another hydraulic line. Component 48 is a brake caliper. Component 49 is a lower transverse link. Component 53 is a transverse link cover. Component 54 is a bracket with brake lines. Component 55 is an upper transverse link. Component 56 is a wheel carrier.

[0042] from Figure 5 As can be seen in the figure, the connecting valve block 18 is designed in a targeted manner so that there is a sufficient spacing from the wheel carrier 56 throughout the entire spring and steering stroke. In addition, the connecting valve block 18 and the hydraulic lines 27, 28 and the further hydraulic line 47 are designed so that there is a sufficient spacing from the brake periphery throughout the entire spring and steering stroke.

Claims

1. A shock absorber (1) comprising a damping piston (6) which can be moved back and forth in an axial direction relative to a main pipe (3) containing a hydraulic medium, wherein: The main pipe (3) is arranged in a container pipe (5), and the intermediate pipe (4) is arranged between the main pipe (3) and the container pipe (5), wherein the main pipe (3), the intermediate pipe (4) and the container pipe (5) are coaxially arranged in a three-tube shock-absorbing structure (2), and the shock-absorbing piston (6) is attached to the end of the piston rod (7), wherein the three-tube shock-absorbing structure (2) is equipped with a hydraulic end position damping member (19) and has a central valve block (12) including two shock-absorbing valve devices (8, 9) at its end facing away from the piston rod (7), characterized in that the central valve block (12) is partially surrounded by an air spring (20), and the air spring includes an air spring housing (50) surrounding the central valve block (12), wherein the three-tube shock-absorbing structure (2) has a gas compensation volume (21) at its end located on the piston rod side, and the gas compensation volume is arranged in the annular space between the intermediate pipe (4) and the container pipe (5).

2. The shock absorber according to claim 1, characterized in that: The air spring housing (50) comprises a housing upper part (51) which surrounds the container tube (5) from the outside.

3. The shock absorber according to claim 2, characterized in that: The three-tube shock-absorbing structure (2) comprises a bellows (58) which surrounds the container tube (5) from the outside above the upper part (51) of the shell.

4. The shock absorber according to claim 2 or 3, characterized in that: The housing upper part (51) is polygonal on the outside.

5. Shock absorber according to any one of the preceding claims, characterized in that The air spring housing (50) comprises a housing lower part (52) which surrounds the container tube (5) from the outside.

6. The shock absorber according to claim 5, characterized in that The housing lower part (52) is polygonal on the outside.

7. The shock absorber according to claim 5 or 6, characterized in that: The housing lower part (52) has at least one recess for a shock absorber valve block (16, 17) on the central valve block (12).

8. The shock absorber according to any one of claims 5 to 7, characterized in that The housing lower part (52) has at least one recess for a connecting valve block (18) on a central valve block (12).

9. A motor vehicle (30) having an active chassis (31) comprising at least one shock absorber (1) according to any one of the preceding claims.

10. A container tube (5), an intermediate tube (4), a main tube (3), a central valve block (12), an air spring housing (50), in particular a housing upper part (51) and / or a housing lower part (52), for a shock absorber (1) according to any one of claims 1 to 8.

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