Vibration damper and motor vehicle with an active suspension

Abstract

Vibration damper (1) with a damper piston (6) which is movable back and forth in a main tube (3) containing hydraulic medium in an axial direction relative to the main tube (3), wherein the main tube (3) is arranged in a reservoir tube (5), wherein an intermediate tube (4) is arranged between the main tube (3) and the reservoir tube (5), wherein the main tube (3), the intermediate tube (4) and the reservoir tube (5) are arranged coaxially in a triple-tube damper (2), wherein the damper piston (6) is attached to one end of a piston rod (7), wherein the triple-tube damper (2) has a central valve block (12) with two damper valve devices (8, 9) at its end facing away from the piston rod (7), wherein the triple-tube damper (2) has a gas compensation volume (21) at its piston-rod-side end, which is arranged in an annular space between the intermediate tube (4) and the reservoir tube (5), characterized in thatthat the triple-tube damper (2) is equipped with a hydraulic end-position damping (19), wherein the central valve block (12) is partially enclosed by an air spring (20) which is supported on an axial support ring (15) which is metallurgically connected to the container tube (5) and the central valve block (12) by a single main weld (60).

Description

[0001] The invention relates to a vibration damper with a damper piston which is movable back and forth in a main tube containing hydraulic medium in an axial direction relative to the main tube, wherein the main tube is arranged in a reservoir tube, wherein an intermediate tube is arranged between the main tube and the reservoir tube, wherein the main tube, the intermediate tube and the reservoir tube are arranged coaxially in a three-tube damper, wherein the damper piston is attached to one end of a piston rod, wherein the three-tube damper has a central valve block with two damper valve devices at its end facing away from the piston rod, and wherein the three-tube damper has a gas compensation volume at its piston rod end, which is arranged in an annular space between the intermediate tube and the reservoir tube.

[0002] German publication DE 11 2012 003 932 T5 of international patent application WO 2013 / 042569 A1 and German patent application DE 10 2019 108 092 B4 disclose motor vehicle shock absorbers in which a valve block is welded to an outer tube. German patent application DE 10 2015 209 179 A1 discloses a cylinder tube for a motor vehicle shock absorber, wherein mounting sleeves of an outer housing accommodating a valve are bonded to a connecting surface of the cylinder tube. German patent application DE 100 25 399 A1 discloses a motor vehicle shock absorber in which a valve housing is welded to a storage tube. German patent application DE 10 2012 009 220 A1 discloses a motor vehicle shock absorber in which a spring retaining ring is bonded to a cylinder section defining a secondary volume.Furthermore, patent application DE 10 2019 211 605 A1 discloses an air spring, patent application DE 10 2021 212 966 A1 discloses a vibration damper in which a welded connection of a pipe block is described, and patent application DE 10 2019 214 905 A1 discloses an air spring strut with a specially designed attachment of a rolling piston.

[0003] A vibration damper of this type is known from German patent application DE 10 2021 202 237 A1, which refers to patent application DE 10 2019 206 455 A1.

[0004] The object of the invention is to improve a vibration damper according to the preamble of claim 1 in terms of functionality and / or manufacturing technology.

[0005] The problem is solved in a vibration damper with a damper piston that is movable back and forth in a main tube containing hydraulic fluid in an axial direction relative to the main tube, wherein the main tube is arranged in a reservoir tube, wherein an intermediate tube is arranged between the main tube and the reservoir tube, wherein the main tube, the intermediate tube and the reservoir tube are arranged coaxially in a triple-tube damper, wherein the damper piston is attached to one end of a piston rod, wherein the triple-tube damper has a central valve block with two damper valve assemblies at its end opposite the piston rod, and wherein the triple-tube damper has a gas compensation volume at its piston-rod end, which is arranged in an annular space between the intermediate tube and the reservoir tube, by equipping the triple-tube damper with hydraulic end-position damping, wherein the central valve block is partially equipped with an air spring.The unit is enclosed and supported by an axial support ring, which is bonded to the reservoir tube and the central valve block by a single main weld. This provides a vibration damper or shock absorber that enables very comfortable operation of a motor vehicle equipped with the vibration damper or shock absorber at both high and low frequencies. This elegantly resolves a space constraint that arises from the combination of the gas compensation volume and the air spring on the triple-tube damper. At the piston-side end of the triple-tube damper, the annular space between the intermediate tube and the reservoir tube is effectively used to house the gas compensation volume. The gas compensation volume is advantageously represented by a gas bag containing a gas, such as air, also known as a gasbag. The gasbag is made of a gas-tight, flexible material. The gasbag orThe gas bag is located between the intermediate tube and the reservoir tube and is connected via a bayonet valve. During operation of the vibration damper, the gas bag ensures separation between the oil and gas. Furthermore, the gas bag prevents the oil from foaming. At the end of the triple-tube damper opposite the piston rod, a sufficiently large air volume can be advantageously provided for the air spring by partially modifying the central valve block. The resulting disadvantage regarding the connection of hydraulic lines to the central valve block is deliberately accepted. Both damper valve assemblies advantageously include a check valve. One of the damper valve assemblies also includes a rebound valve. The other damper valve assembly advantageously includes a compression valve in addition to the check valve. The central valve block is preferably machined.The main weld seam allows the air spring to be easily and stably supported axially at the lower end of the container pipe and the central valve block.

[0006] A preferred embodiment of the vibration damper is characterized in that the axial support ring has a rectangular ring cross-section. This significantly simplifies the application of the weld seam to the axial support ring, the container tube, and the central valve block.

[0007] Another preferred embodiment of the vibration damper is characterized in that the axial support ring is combined with a support sleeve that surrounds the container tube on the outside. This increases the stability of the container tube at the end with the axial support ring. Furthermore, the support sleeve allows for a particularly simple design of a tensile restraint for the air spring supported by the axial support ring in the installed state.

[0008] Another preferred embodiment of the vibration damper is characterized in that the support sleeve has a chamfer on the outside at an end facing away from the axial support ring. This simplifies the assembly and fastening of the air spring.

[0009] Another preferred embodiment of the vibration damper is characterized in that the support sleeve is combined with an adapter body that serves to provide axial tensile restraint for the air spring mounted on the axial support ring. This significantly simplifies the assembly of the air spring.

[0010] Another preferred embodiment of the vibration damper is characterized in that the air spring has an air spring housing which is fixed to the adapter body in an axial direction by a snap or detent connection. Snap hooks or detent hooks for representing the detent or snap connection are advantageously attached to the air spring housing, in particular to a lower housing part of the air spring housing. Both the air spring housing and the adapter body are advantageously made of a plastic material. This enables cost-effective production in large quantities, for example, using an injection molding process.

[0011] Another preferred embodiment of the vibration damper is characterized in that the main weld seam is arranged on an annular surface of the axial support ring facing the central valve block. This simplifies the welding of the axial support ring to the container pipe and the central valve block.

[0012] Another preferred embodiment of the vibration damper is characterized in that the main weld is arranged on an outer circumferential surface of a base block of the central valve block. The base block has, for example, the shape of a straight circular cylinder. Advantageously, the main weld extends completely around the outside of the container tube. This ensures a very stable attachment of the axial support ring to the container tube and the central valve block in a simple manner.

[0013] The invention further relates to a motor vehicle with an active suspension system comprising at least one vibration damper as previously described. The claimed motor vehicle advantageously comprises a front axle and a rear axle, each equipped with a motor-pump unit and two vibration dampers.

[0014] Further advantages, features, and details of the invention will become apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. The drawing shows: Fig. 1 a perspective view of a strut with a three-tube damper; Fig. 2 the triple-tube damper Fig. 1 in a schematic sectional view; Fig. 3 the triple-tube damper Fig. 1 in a longitudinal section view, where one container pipe of the triple-pipe damper is not shown in section; Fig. 4 a perspective view of a vibration damper with a three-tube damper, which is enclosed with an air spring at one end facing a front axle; Fig. 5 a vibration damper with a triple-tube damper assigned to a rear axle of a motor vehicle; and the Fig. 6 an enlarged section from Fig. 3 in a half longitudinal section.

[0015] In the Fig. 1, Fig. 2 to Fig. Figure 3 shows a spring strut 10 with a spring fork 11 in various views. The spring strut 10 includes a vibration damper 1, which is also referred to as a shock absorber. The vibration damper 1 is designed as a three-tube damper 2 with a main tube 3, an intermediate tube 4, and a reservoir tube 5.

[0016] The strut 10 with the vibration damper 1, designed as a triple-tube damper 2, is part of a hydraulic system used in a motor vehicle to provide active damping control during operation. The motor vehicle preferably comprises four wheels, each of which is assigned a vibration damper 1 designed as a triple-tube damper 2. The triple-tube damper or vibration damper is also referred to simply as a damper. In the active suspension of the motor vehicle, the hydraulic damper acts as a shock absorber.

[0017] The triple-tube damper 2 is operated with a hydraulic medium. The hydraulic medium is preferably a hydraulic fluid, also referred to as hydraulic oil or simply oil. In addition to a hydraulic damper volume, the hydraulic damper includes a gas compensation volume 21.

[0018] The active damping control system comprises a hydraulic actuator unit that is hydraulically connected to the dampers via hydraulic lines. In the active suspension of the vehicle, the hydraulic actuator unit serves to selectively activate or control the hydraulic dampers. For this purpose, the hydraulic actuator unit advantageously includes a separate hydraulic pump for each damper. Two hydraulic pumps per axle of the vehicle can be combined in a single motor-pump unit. The hydraulic pumps assigned to each axle are advantageously controllable separately via a common control unit.

[0019] In the main tube 3 of the triple-tube damper 2 is a damper piston 6 in Fig. 2. The piston is guided so that it can move downwards and upwards. A piston rod 7 extends from the damper piston 6, which is located in Fig. 2 extends upwards through a sealing guide unit 32 out of the triple-tube damper 2. One in Fig. 2 The upper end of the piston rod 7, not shown, is connected to a supporting structure of the motor vehicle.

[0020] The main tube 3, the intermediate tube 4, and the reservoir tube 5 are arranged coaxially and provided with gaps in the radial direction. An annular space between the main tube 3 and the intermediate tube 4 allows the hydraulic medium to flow through, in particular a downward return of the hydraulic medium, without the need for additional hydraulic lines. An annular space between the intermediate tube 4 and the reservoir tube 5 advantageously serves to accommodate the gas equalization volume 21.

[0021] The gas compensation volume 21 is represented by a gas bag 22, which is located at a piston rod-side end of the triple-tube damper 2, i.e., in Fig. 2 above, between the intermediate tube 4 and the holding 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 19 with a hydraulic pull stop 39.

[0022] At his in Fig. At its lower end, the triple-tube damper 2 is equipped with a central valve block 12. Two damper valve assemblies 8 and 9 are integrated into the central valve block 12. Each damper valve assemblies 8 and 9 includes a check valve.

[0023] Furthermore, the damper valve assembly 8 includes a rebound valve which is hydraulically connected via an annular gap 71 to the annular space between the main tube 3 and the intermediate tube 4. The main tube 3 is in Fig. 2 below connected via a relatively large central through-hole 72 to a pressure stage valve in the damper valve assembly 9.

[0024] The central valve block 12 comprises a base block 13, which is designed, for example, as a solid tube body. The base block 13 has, for example, the external shape of a straight circular cylinder. The base block 13 is designed, for example, as a milled part and is attached to the lower end of the triple-tube damper 2.

[0025] The central valve block 12 further comprises two damper valve blocks 16, 17, which essentially have the shape of straight circular cylinders. The two damper valve blocks 16, 17 can be integrally connected to the base block 13. The damper valve blocks 16, 17 serve to accommodate and / or represent the damper valve assemblies 8 and 9. The two damper valve blocks 16, 17 are arranged coaxially to each other and transversely to the longitudinal axis of the triple-tube damper 2.

[0026] The central valve block 12 further comprises a connection valve block 18. The connection valve block 18 is designed as a separate component and is attached to the base block 13. For example, two screws 73, 74 are used to attach the connection valve block 18 to the base block 13 of the central valve block 12.

[0027] Designing the connection valve block 18 as a separate component offers several advantages, including the ability to create package-dependent designs for the vibration damper with relatively little design effort, particularly when installing it in different vehicle variants or derivatives. Furthermore, the separate connection valve block 18 can be designed and positioned on the base block 13 in such a way as to ideally meet specific crash requirements for a vehicle equipped with the vibration damper 1.

[0028] With regard to the package-dependent design of the connection valve block 18, the positioning of hydraulic connections 23, 24 is particularly important. As can be seen especially in the Fig. 4 and Fig. 5 shows the connection for hydraulic lines 27, 28. The triple-tube damper 2 can be actively hydraulically controlled via the hydraulic lines 27, 28. For this purpose, the hydraulic lines 27, 28 are hydraulically integrated into an active damping control 29, which is located in Fig. 4 is only indicated by a rectangle.

[0029] In the Fig. 4 and Fig. Figure 5 illustrates in perspective how the three-tube damper 2 with the central valve block 12 at its lower end can be designed to fit the installation space, especially when installed in a motor vehicle 30 with an active suspension 31.

[0030] The in the Fig. 4 and Fig. 5 only with the help of various components 43 to 46 in Fig. 4 and 47 to 49, 53 to 56 in Fig. The depicted motor vehicle 30 places high demands on a designer, particularly because hoses and lines, especially the hydraulic lines 27, 28, require sufficient clearance to the surrounding components throughout the entire spring and steering stroke during operation of the motor vehicle 30. Furthermore, the bending radii and stretch lengths that occur must be taken into account.

[0031] An additional design effort arises from the fact that the vibration damper 1, designed as a three-tube damper 2, as can be seen, for example, in Fig. 3, which is also combined with an air spring 20. The air spring 20 is advantageously designed and arranged such that it surrounds the central valve block 12 from the lower end of the triple-tube damper 2. This maximizes the air spring space that can be created with the air spring 20. Due to the large volume, the air spring 20 can be advantageously made softer. Furthermore, the design and arrangement of the air spring 20 on and around the central valve block 12 result in packaging advantages.

[0032] The air spring 20 comprises an air spring housing 50 with an upper housing part 51 and a lower housing part 52. The air spring housing 50 contains a single, relatively large volume of air. The air spring housing 50 extends around the lower end of the triple-tube damper 2 with the central valve block 12. In the axial direction, the air spring housing 50 is arranged between a bellows 58 and the central valve block 12, which is partially enclosed by the lower housing part 52.

[0033] The air spring housing 50 is supported by its lower housing part 52 on an axial support ring 15, which is attached to the lower end of the triple-tube damper 2. The axial support ring 15 is combined with an adapter body 14, which allows the air spring housing 50 to be attached externally to the reservoir tube 5 of the triple-tube damper 2. The air spring housing 50 is attached to the adapter body 14, for example, by a snap-fit ​​or detent connection.

[0034] In Fig. Figure 4 shows how the air spring housing 50 of the air spring 20 surrounds the central valve block 12 in such a way that the connection valve block 18 remains free. Fig. Component 4 is the triple-tube damper 2 of a front axle of the motor vehicle 30. Component 43 is a brake air supply. Component 44 is a lower control arm. Component 45 is a tie rod. Component 46 is a driveshaft.

[0035] In Fig. Figure 4 shows how the air spring volume of the air spring 20 extends around the connection valve block 18. Thus, a maximum air spring volume can be represented with the air spring housing 50. Furthermore, it can be seen in Fig. 4, that the connection valve block 18 is designed in such a way that, firstly, the connection of the hydraulic lines 27, 28 to the central valve block 12 is simplified. In addition, the shut-off screws 41, 42 of shut-off valves 25, 26 integrated into the connection valve block 18 are still accessible even when the air spring 20 is installed.

[0036] In Fig. Component 5 is the triple-tube damper 2 of a rear axle of the motor vehicle 30. Component 47 is another hydraulic line. Component 48 is a brake caliper. Component 49 is a lower control arm. Component 53 is a control arm cover. Component 54 is a bracket with a brake line. Component 55 is an upper control arm. Component 56 is a wheel carrier.

[0037] In Fig. Figure 5 shows that the connection valve block 18 is specifically designed to ensure sufficient clearance to the wheel carrier 56 throughout the entire spring and steering stroke. Furthermore, the connection valve block 18, the hydraulic lines 27, 28, and the additional hydraulic line 47 are designed to ensure sufficient clearance to the brake components throughout the entire spring and steering stroke.

[0038] In Fig. 6 is an excerpt from Fig. 3 shown in half-section. In the sectional view of the Fig. Figure 6 shows that the base block 13 of the central valve block 12 is connected to its base block by a short piece. Fig. The upper end of the central valve block 12 is located inside the container pipe 5. The base block can be designed accordingly for this purpose. This simplifies the positioning of the central valve block 12 relative to the container pipe 5.

[0039] At the in Fig. At the lower end of the container pipe 5, an axial support ring 15 is welded to both the container pipe 5 and the central valve block 12, in particular to the base block 13 of the central valve block 12, by means of a circumferential main weld 60. The main weld 60 thus joins three components together in a metallurgical bond.

[0040] The axial support ring 15 is combined with a support sleeve 61. The support sleeve 61 surrounds the container pipe 5 above the axial support ring 15. The support sleeve 61 is firmly connected to the container pipe 5. The support sleeve 61 serves, firstly, to ensure the stability of the container pipe 5 at its Fig. 6 to increase the lower end.

[0041] Furthermore, the support sleeve 61 serves to attach an adapter body 64 to the container tube 5. The adapter body 64, in turn, serves as a tension restraint for the air spring when the air spring housing 50 is placed on the axial support ring 15. A chamfer 62 simplifies the assembly of the adapter body 64.

Claims

[1] Vibration damper (1) with a damper piston (6) which is movable back and forth in a main tube (3) containing hydraulic medium in an axial direction with respect to the main tube (3), wherein the main tube (3) is arranged in a reservoir tube (5), wherein an intermediate tube (4) is arranged between the main tube (3) and the reservoir tube (5), wherein the main tube (3), the intermediate tube (4) and the reservoir tube (5) are arranged coaxially in a triple-tube damper (2), wherein the damper piston (6) is attached to one end of a piston rod (7), wherein the triple-tube damper (2) has a central valve block (12) with two damper valve assemblies (8, 9) at its end opposite the piston rod (7), wherein the triple-tube damper (2) has a gas compensation volume (21) at its piston rod end, which is arranged in an annular space between the intermediate tube (4) and the reservoir tube (5), characterized by, that the triple-tube damper (2) is equipped with a hydraulic end-position damping (19), wherein the central valve block (12) is partially enclosed by an air spring (20) which is supported on an axial support ring (15) which is materially bonded to the container tube (5) and the central valve block (12) by a single main weld (60). [2] Vibration damper according to claim 1, characterized by , that the axial support ring (15) has a rectangular ring cross-section. [3] Vibration damper according to any one of the preceding claims, characterized by , that the axial support ring (15) is combined with a support sleeve (61) that surrounds the container tube (5) on the outside. [4] Vibration damper according to claim 3, characterized by , that the support sleeve (61) has a chamfer (62) on the outside at an end facing away from the axial support ring (15). [5] Vibration damper according to claim 3 or 4, characterized by, that the support sleeve (61) is combined with an adapter body (64) which serves to provide an axial tensile restraint for the air spring (20) mounted on the axial support ring (15). [6] Vibration damper according to claim 5, characterized by , that the air spring (20) has an air spring housing (50) which is fixed to the adapter body (64) in an axial direction by a snap or detent connection. [7] Vibration damper according to any one of the preceding claims, characterized by , that the main weld (60) is arranged on an annular surface of the axial support ring (15) facing the central valve block (12). [8] Vibration damper according to any one of the preceding claims, characterized by , that the main weld (60) is arranged on an outer circumferential surface of a base block (13) of the central valve block (12). [9] Motor vehicle (30) with an active suspension (31) comprising at least one vibration damper (1) according to any of the preceding claims.

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