Vibration damper for motor vehicle

Abstract

The invention relates to a shock absorber (10) for a vehicle, comprising: a shock absorber tube (14) filled with a hydraulic fluid; a working piston (18) connected to the piston rod (20) and arranged to be capable of reciprocating within the damper tube, the interior of the damper tube being divided by the working piston into a first working chamber (22) and a second working chamber (24); a pressure stop (48) having an auxiliary piston (50); and a pressure stop receptacle (82) mounted inside the damper tube (14) to receive the auxiliary piston; the additional piston (50) is arranged so as to be axially movable in the pressure stop receptacle (82) and divides the interior of the pressure stop receptacle (82) into a compression phase working chamber (56); the additional piston (50) and the piston rod (20) are arranged so as to be movable independently of one another, and a damping element (28) is arranged between the piston rod (20) and the additional piston (50) for damping the contact of the piston rod with the additional piston in the compression phase.

Description

Technical Field

[0001] The present invention relates to a shock absorber for motor vehicles having a pressure stop device. Background Technology

[0002] DE102023105059A1 discloses a hydraulic shock absorber with a hydraulic pressure stop. Hydraulic pressure stops are typically used to provide additional damping during the compression phase of a shock absorber. In known shock absorbers, an additional piston extends into the pressure stop chamber as the piston rod moves in the compression direction, thereby generating additional damping. The components interacting during compression damping must typically meet very precise manufacturing tolerances, for example, to compensate for lateral forces on the piston rod. Therefore, manufacturing these components is often very costly. Furthermore, mounting space for the pressure stop is limited, especially in shock absorbers with external damping valves or in monotube shock absorbers with external air chambers. Additionally, the noise generated when activating additional damping during the compression phase must be minimized to a level inaudible to the driver of the motor vehicle. Summary of the Invention

[0003] Based on this, the purpose of the present invention is to provide a vibration damper with a pressure stop device, which is low in manufacturing cost, easy to install and has low noise.

[0004] The present invention achieves the objective by a vibration damper having the features described in independent claim 1. Advantageous improvements can be obtained in the dependent claims.

[0005] According to a first aspect, a shock absorber for a vehicle includes: a shock absorber tube filled with hydraulic fluid; a working piston connected to a piston rod and arranged to reciprocate within the shock absorber tube, wherein the interior of the shock absorber tube is divided by the working piston into a first working chamber located on the piston rod side and a second working chamber located on the opposite side of the piston rod. The shock absorber preferably further includes a sealing assembly that fluid-tightly seals the shock absorber tube on the piston rod side. Furthermore, the shock absorber includes a pressure stop device having an additional piston and a pressure stop receptacle mounted inside the shock absorber tube to receive the additional piston, wherein the additional piston is arranged to move axially within the pressure stop receptacle and to separate a compression phase working chamber within the pressure stop receptacle. The additional piston and piston rod are arranged to move independently of each other. The shock absorber also has a damping element disposed between the piston rod and the additional piston and designed and arranged to dampen the contact between the piston rod and the additional piston during the compression phase.

[0006] The auxiliary piston is arranged along the compression direction of the piston rod, wherein the piston rod is preferably movable between a position spaced apart from the auxiliary piston and a position where the piston rod is in contact with the auxiliary piston. During the compression phase, the piston rod moves along the compression direction until it contacts the auxiliary piston and drives the auxiliary piston to move along the compression direction. A damping element between the piston rod and the auxiliary piston reliably minimizes the noise generated by the piston rod impacting the auxiliary piston.

[0007] The shock absorber is, for example, a single-tube or multi-tube shock absorber. For instance, a multi-tube shock absorber for a vehicle includes an outer tube and an inner tube arranged coaxially with the outer tube, wherein a compensation space for receiving hydraulic fluid is formed between the outer and inner tubes; it also includes a working piston connected to a piston rod, the working piston being arranged such that it can reciprocate within the inner tube, wherein the interior of the inner tube is divided by the working piston into a first working chamber on the piston rod side and a second working chamber on the piston rod-away side. The compensation chamber is preferably at least partially filled with gas, particularly at the upper end. The outer tube preferably constitutes at least a portion of the shock absorber housing. The inner surface of the inner tube is preferably designed as a guide for the working piston. The working piston preferably has a valve device through which the first and second working chambers are interconnected. In a single-tube shock absorber, there is no outer tube. The inner tube, referred to as the shock absorber tube, houses the piston rod and the working piston as described above for the inner tube.

[0008] In multi-tube vibration dampers, a sealing assembly is particularly provided, designed and arranged to provide a fluid seal to the interior of the outer tube on the piston rod side. The piston rod end of the inner tube is preferably attached to the sealing assembly. At the end opposite the sealing assembly, away from the piston rod, a compensation chamber and a second working chamber are preferably fluid-sealed via a base element. The compensation chamber is preferably connected to either the first or second working chamber through an opening in the inner tube. For example, the compensation chamber is sealed relative to the inner tube via a base element. The sealing assembly is preferably arranged coaxially with the piston rod and circumferentially surrounding it.

[0009] In a single-tube shock absorber, the shock absorber particularly features a sealing assembly designed and arranged to seal the interior of the shock absorber tube on the piston rod side in a fluid-technical manner. The piston rod end of the shock absorber tube is preferably attached to the sealing assembly. At the end opposite the sealing assembly, away from the piston rod, the interior of the shock absorber tube is preferably sealed relative to fluid flow by a sealing element that is axially movable. This sealing element preferably separates, in the axial direction, its adjacent air chamber and the working chamber filled with hydraulic fluid.

[0010] In the following description, the term "damper" refers to both multi-tube and single-tube dampers, where the damper tube is the inner tube of a multi-tube damper.

[0011] The pressure stop device is preferably located inside the damper tube, particularly in the end region of the damper tube away from the piston rod, and preferably includes a pressure stop housing and an auxiliary piston. The auxiliary piston is axially movably mounted within the pressure stop housing and its outer circumferential surface preferably at least partially or completely abuts against the inner wall of the pressure stop housing in a fluid-tight manner. The auxiliary piston is preferably not connected to the piston rod. The auxiliary piston and piston rod are particularly mounted such that they are movable relative to each other. The pressure stop device also includes a compression stage working chamber, which is divided by the auxiliary piston within the damper tube (particularly within the pressure stop housing).

[0012] In the following description, "movement in the stretching direction" should be understood as movement in the direction toward the sealing assembly within the piston rod side region of the damping buffer; and "movement in the compression direction" should be understood as movement in the direction toward the base member within the region of the damping buffer away from the piston rod.

[0013] According to a first embodiment, the damping element is attached to the piston rod or an auxiliary piston. Optionally, the damper has two or more damping elements, wherein at least one damping element is attached to the piston rod and at least one damping element is attached to an auxiliary piston. The damping element is particularly attached to the end face of the auxiliary piston facing the piston rod, or to the end face of the piston rod facing the auxiliary piston.

[0014] According to another embodiment, the piston rod or auxiliary piston has a groove in which a damping element is disposed. Preferably, the piston rod has a contact surface for contacting the auxiliary piston, particularly formed on the end face of the piston rod facing the auxiliary piston. The groove is formed on the contact surface of the piston rod. Preferably, the auxiliary piston has a contact surface facing the piston rod and this contact surface is designed for contacting the piston rod (particularly the contact surface with the piston rod). The contact surface of the auxiliary piston preferably forms an end face facing the piston rod and preferably has a groove in which the damping element is disposed.

[0015] The additional piston preferably includes a valve body having at least one or more axially through holes, which are at least partially or completely covered by a valve plate on the piston rod side. The valve plate is preferably preloaded such that when a certain pressure is reached in the compression stage working chamber, the valve plate allows (hydraulic fluid) to flow from the compression stage working chamber into the second working chamber through the through holes. Therefore, the through holes and the valve plate together prevent the pressure in the compression stage working chamber from rising above a certain value.

[0016] The valve body preferably has a radially outwardly pointing shoulder at its piston rod end, which forms an axial contact surface for the throttling element. The throttling element is preferably mounted around the outer periphery of the valve body and is particularly designed and arranged such that it fluid-tightly seals against the inner wall of the damper tube. For example, the throttling element has a through opening through which hydraulic fluid can flow. The auxiliary piston preferably has a plate disposed at the end of the auxiliary piston (especially the valve body) remote from the piston rod. The valve body, valve plate, and plate are preferably connected by connecting elements (e.g., screws or rivets, optionally with washers). The plate preferably extends radially beyond the valve body and forms an axial contact surface for the throttling element. For example, grooves are formed in the connecting elements, valve body, or plate.

[0017] According to another embodiment, the volume of the groove is larger than the volume of the damping element. This has the advantage that when the damping element impacts the auxiliary piston or piston rod, the damping element is completely contained within the groove, and in particular, does not protrude from the groove. This significantly minimizes wear on the damping element. Preferably, the volume of the damping element is approximately 50% to 95% of the groove volume, particularly 70% to 90%, and preferably 80%. Preferably, the damping element is designed such that when the piston rod impacts the auxiliary piston, the damping element elastically deforms, causing the piston rod to at least partially abut against the auxiliary piston with its front side. In particular, the damping element is designed such that when the piston rod impacts the auxiliary piston, the damping element elastically deforms, causing it to be completely contained within the groove and not protrude beyond the groove in the axial direction.

[0018] According to another embodiment, the damping element is made of an elastic material. The damping element is preferably made of an elastic material, such as rubber (especially ECO black rubber) or TEEE (thermoplastic).

[0019] According to another embodiment, the damping element is designed and arranged such that: in a first position where the piston rod and the auxiliary piston are spaced apart from each other, the damping element protrudes axially from the groove, and in a second position where the piston rod and the auxiliary piston are in contact with each other, the damping element is completely located within the groove. This minimizes wear on the damping element. Preferably, in the second position, the contact surface of the auxiliary piston is in contact with the contact surface of the piston rod. The contact surfaces are preferably made of steel, so that in the absence of damping, audible noise is generated when the contact surfaces collide.

[0020] According to another embodiment, the damping element is in the shape of a ring, a sphere, a cuboid, a cube, a pyramid, or a cone.

[0021] According to another embodiment, the damping element is press-fitted into the groove. Specifically, the damping element is secured in the groove by force-locking, form-locking, and / or material-locking connections. Press-fitting provides a simple and reliable method for securing the damping element.

[0022] According to another embodiment, the damping element has a surface having at least one or more protrusions and recesses. Preferably, the end face of the damping element away from the groove has a plurality of protrusions and recesses, which are particularly equidistant from each other. Preferably, the end face of the damping element is wavy.

[0023] The damping element is preferably crown-shaped. In particular, the damping element is annular in shape, with its end face away from the groove having a profile such as wavy or sawtooth.

[0024] According to another embodiment, the groove is cylindrical, hemispherical, or annular in shape.

[0025] According to another embodiment, a reset element is arranged inside the damping element. The reset element is, for example, a wave spring, which is preferably arranged entirely inside the damping element. The reset element is particularly made of metal. Preferably, the profile of the reset element conforms to the surface geometry of the front side of the damping element.

[0026] According to another embodiment, the piston rod has a first piston rod section and a second piston rod section, a working piston is attached to the first piston rod section, the second piston rod section is adjacent to the working piston in the compression direction, and a damping element is attached to the second piston rod section. Optionally, the piston rod further includes a second piston rod section, which is designed, for example, as an additional piston rod separate from the first piston rod section and adjacent to the working piston in the axial direction (especially in the compression direction). The diameter of the second piston rod section is preferably substantially the same as the diameter of the first piston rod section of the piston rod. The second piston rod section constitutes the axial extension of the piston rod.

[0027] The pressure stop receiver preferably has a bypass opening formed at the piston rod end of the pressure stop receiver. The bypass opening is preferably designed such that its flow cross-section decreases in the compression direction. The bypass opening is preferably designed as a front cutout in the pressure stop receiver, wherein the area of ​​the bypass opening decreases in the compression direction along the pressure stop receiver. The bypass path formed by the bypass opening has a flow cross-section that decreases as the auxiliary piston moves in the compression direction. For example, this increases the damping of the auxiliary piston as it moves in the compression direction, thereby achieving progressive damping. Preferably, no bypass opening is formed in the region of the pressure stop receiver remote from the piston rod. This ensures that maximum damping is set before the auxiliary piston comes to a stop against the base member.

[0028] Optionally, the damper has an adapter installed inside the damper tube for attaching a damping valve device; or it has a flow channel formed inside the damper tube for connecting a compensation device; wherein an additional piston is arranged between the adapter or flow channel and the end of the damper tube away from the piston rod.

[0029] The damper may also optionally include a damping valve device, which is preferably attached to the damper tube via an adapter. The damping valve device is preferably fluidly connected to a second working chamber (particularly the interior of the damper tube) via an adapter. The damping valve device is, for example, a solenoid valve, which is particularly continuously adjustable. Optionally, the damping valve device is used only to provide additional damping during the compression phase.

[0030] The adapter is preferably installed entirely inside the damper tube, particularly in the working chamber of the damper tube away from the piston rod, and is preferably connected to the damper tube in a fixed position. In the axial direction, the adapter is preferably arranged spaced apart from the base member. For example, the adapter is arranged and designed such that it restricts the movement of the auxiliary piston in the tension direction. Optionally, the adapter constitutes an axial stop for the movement of the auxiliary piston in the tension direction, wherein the tension stop is particularly abutted against the adapter. The adapter is, for example, sleeve-shaped, and particularly constitutes a narrowing of the inner diameter of the damper tube.

[0031] The pressure stop receiver is particularly designed in a sleeve shape. Preferably, the additional piston is fluid-tightly abutted against the inner wall of the pressure stop receiver, wherein the pressure stop receiver constitutes a guide for the additional piston. Preferably, the additional piston and piston rod are movable independently of each other. This allows the piston rod to move without carrying the additional mass of the additional piston during normal operation of the damping buffer, wherein the additional piston is driven by the piston rod to move within the pressure stop chamber only during the damping phase of compression.

[0032] Optionally, a spring element is arranged between the auxiliary piston and the end of the damper tube furthest from the piston rod. The pressure stop device particularly includes this spring element, which preferably has its respective end regions abutting against the auxiliary piston and the end of the damper tube. The spring element is, for example, a helical spring. Preferably, the spring element is preloaded relative to the auxiliary piston, such that it applies a force to the auxiliary piston in the tensile direction.

[0033] Preferably, the auxiliary piston has a bypass passage and a throttling element for adjusting the flow cross-section of the bypass passage, wherein the throttling element is mounted movably in the axial direction. The bypass passage is particularly formed between the valve body and the throttling element. The bypass passage is added to the through-hole configuration and provides additional flow passage when the auxiliary piston moves in the compression or tension direction.

[0034] In particular, the bypass passage is at least partially formed by grooves in the valve body. These grooves are preferably formed in the radially outward circumferential surface of the valve body. For example, the valve body has multiple grooves, which are arranged equidistantly from each other in the circumferential direction. In particular, the plate has multiple cutouts. The bypass passage is preferably formed by cutouts in the plate, grooves in the valve body, and throttling elements.

[0035] The throttling element is preferably designed and arranged such that it releases a first flow cross-section of the bypass passage in a first position and a second flow cross-section of the bypass passage in a second position. According to another embodiment, the first flow cross-section is smaller than the second flow cross-section. According to another embodiment, the throttling element is arranged such that it moves to the first position when the auxiliary piston moves in the compression direction, and to the second position when the auxiliary piston moves in the extension direction. This results in greater damping for the auxiliary piston when it moves in the compression direction than when it moves in the extension direction. Therefore, the auxiliary piston functions as a pressure stop while providing additional damping to the piston rod in the compression direction.

[0036] The throttling element is preferably arranged and designed such that when the auxiliary piston moves in the compression direction, the throttling element abuts against a shoulder of the valve body and at least partially or completely closes the bypass passage. Preferably, the bypass passage includes a first flow cross-section, which coincides, for example, with the cross-section of the through opening in the throttling element. The throttling element is preferably arranged and designed such that when the auxiliary piston moves in the extension direction, the throttling element abuts against a shoulder (especially against a plate) away from the piston rod and releases the bypass passage (especially the second flow passage).

[0037] For example, the throttling element is designed as an annular ring. A throttling element designed as a piston ring, for example, has a through opening designed as a slot, which forms a complete circumferential interruption of the annular piston ring. Attached Figure Description

[0038] The present invention will now be described in more detail with reference to several exemplary embodiments and accompanying drawings.

[0039] Figure 1 A schematic diagram of a vibration damper according to an exemplary embodiment is shown in longitudinal sectional view.

[0040] Figure 2 A schematic diagram showing details of a vibration damper according to another exemplary embodiment is presented in longitudinal sectional view.

[0041] Figure 3 A perspective view shows a schematic diagram of the details of the piston rod of a shock absorber according to another exemplary embodiment.

[0042] Figure 4a A schematic diagram showing details of the piston rod of a shock absorber according to another exemplary embodiment is presented in longitudinal sectional view.

[0043] Figure 4b A perspective view shows a schematic diagram of the details of the piston rod of a shock absorber according to another exemplary embodiment.

[0044] Figure 5A schematic diagram showing details of a vibration damper according to another exemplary embodiment is presented in longitudinal sectional view.

[0045] Figure 6 A schematic diagram of an additional piston according to another exemplary embodiment is shown in longitudinal sectional view. Detailed Implementation

[0046] Figure 1 A vibration damper 10 is shown, which is, for example, a multi-tube vibration damper, such as a dual-tube vibration damper. The vibration damper 10 has an outer tube 12, which forms the outer surface of the vibration damper 10, and more particularly, the housing of the vibration damper. Inside the outer tube 12, a vibration damper tube 14, also referred to as the inner tube, is arranged coaxially with the outer tube. A compensation cavity 16 is formed between the outer tube 12 and the inner tube 14, and this compensation cavity is preferably at least partially or completely filled with hydraulic fluid. For example, the compensation cavity 16 is partially filled with gas.

[0047] A working piston 18, connected to piston rod 20, is arranged inside inner tube 14 such that the working piston can move within inner tube 14, wherein inner tube is preferably designed as a guide for working piston 18. Working piston 18 preferably has valve devices. For example, the valve devices include a tension stage valve for damping piston movement during the tension stage and a compression stage valve for damping piston movement during the compression stage. Preferably, each valve consists of a through opening through the piston and a valve plate assembly. Working piston 18 divides the interior of inner tube 14 into a first working chamber 22 located on the piston rod side and a second working chamber 24 located away from the piston rod. Piston rod 20 is preferably connected to the vehicle body via its end extending out of damper tube 14. For example, piston rod 20 has a first piston rod section 21 extending to working piston 18, to which working piston 18 is attached. Working piston 18 is preferably attached to the end region of the first piston rod section 21 opposite to the end of piston rod 20 extending out of damper tube 14. For example, piston rod 20 includes a second piston rod segment 44, and more particularly, an additional piston rod 42 connected to the working piston 18 in the axial direction (especially in the compression direction D). The additional piston rod 42 preferably constitutes an axial extension of piston rod 20 (especially the first piston rod segment 21). The diameter of the additional piston rod 42 is preferably substantially the same as the diameter of the first piston rod segment 21 of piston rod 20. For example, the additional piston rod 42 has two different diameters. In a first region of the piston rod, the additional piston rod 42 has, for example, a first diameter that matches the diameter of piston rod 20. In a second region of the additional piston rod 42 away from the piston rod, the additional piston rod 42 has, in particular, a second diameter smaller than the first diameter. The second piston rod segment 44 preferably has an axial length greater than the axial length of the adapter (not shown) for attaching the damping valve device. It may also be included that the damper 10 does not have a separate additional piston rod 42. In this case, with... Figure 1 and Figure 2 Compared to the piston rod 20 in the first piston rod, the piston rod 20 has an extension portion. This piston rod 20 extends beyond the working piston 18 along the compression direction D. Preferably, this extension portion is the area where the piston rod 20 extends beyond the working piston 18 along the compression direction D. This extension portion is preferably integrally formed with the piston rod 20 and / or made as a single piece.

[0048] The interior of the outer tube 12 is sealed on the piston rod side by a sealing assembly 34. At the end opposite the sealing assembly 34, away from the piston rod, the compensation chamber 16 is sealed by a base member 36. The interior of the damper tube 14 (particularly the second working chamber 24) is preferably also sealed relative to the fluid by the base member 36. Alternatively, a separate base element, separate from the base member, can be provided to seal the outer tube. Preferably, the damper 10 does not have a base valve. The piston rod end of the inner tube 14 is preferably attached to the sealing assembly 34.

[0049] The outer tube 12 is preferably cylindrical and optionally has a smaller diameter at the piston rod end region, which is at least partially surrounded by the end cap 26. The end cap 26 forms the end part of the outer tube 12 and at least partially surrounds the sealing assembly 34.

[0050] For example, the damper 10 includes a tension stop 46 fixedly attached to the piston rod 20. The tension stop 46 is, for example, annular and disposed within a first working chamber 22 between the working piston 18 and the sealing assembly 34. Preferably, the tension stop 46 (particularly the end face facing the sealing assembly 34) forms a stop surface that contacts the sealing assembly 34 when the piston rod moves in the tension direction Z. The tension stop 46 serves to limit the movement of the piston rod in the tension direction Z. For example, the damper 10 includes a tension stop sleeve 30 coaxially mounted to the damper tube 14 and mounted on the sealing assembly side at the end of the damper tube 14. Preferably, the outer surface of the tension stop sleeve 30 abuts against the inner surface of the damper tube 14. The tension stop sleeve 30 is preferably designed to axially guide the tension stop during the tensioning phase. Optionally, the shock absorber 10 is not provided with a tension stop sleeve 30. In this case, a flow gap is formed between the tension stop 46 and the inner wall of the shock absorber tube 14, through which hydraulic fluid can flow during the piston rod movement.

[0051] The damper 10 optionally includes two or exactly one damping valve device (not shown) for damping the movement of the piston rod during the tension and compression phases. The direction of movement of the piston rod 20 during the compression phase D and the tension phase Z is as follows: Figure 1The damping valve device is shown by arrows Z and D. It is in fluid communication with the second working chamber 24 (particularly the interior of the damper tube 14) via a sleeve-shaped adapter (not shown). The damping valve device is, for example, a solenoid-controlled valve, which is particularly continuously adjustable. Optionally, the damping valve device is used only to provide additional damping during the compression phase.

[0052] For example, the damper 10 includes a pressure stop device 48 disposed inside the damper tube 14, particularly in the end region of the damper tube 14 remote from the piston rod. The pressure stop device 48 preferably includes a pressure stop receiving member 82 and an auxiliary piston 50, which is axially movable within the pressure stop receiving member 82 and preferably at least partially or completely fluid-tightly abuts the inner wall of the pressure stop receiving member 82 with its outer circumferential surface. Preferably, the auxiliary piston 50 is axially movable within the pressure stop receiving member 82, wherein the pressure stop receiving member 82 serves as a guide for the auxiliary piston 50. For example, the auxiliary piston 50 is not attached to the piston rod 20 or the auxiliary piston rod 42. The pressure stop device 48 also particularly includes a spring element 52, which is preferably disposed between the auxiliary piston 50 and the base member 36, with each end region abutting against the auxiliary piston and the base member, respectively. The spring element 52 is, for example, a coil spring. In particular, the additional piston 50 divides the pressure stop receiver 82 into a compression stage working chamber 56. The compression stage working chamber 56 is preferably arranged entirely within the pressure stop receiver 82. For example, the pressure stop receiver 82 is sleeve-shaped and fluid-tightly attached to the base member 36, especially by means of its end away from the piston rod. Preferably, the pressure stop receiver 82 fluid-tightly abuts against the inner wall of the damper tube 14 by means of its outer diameter.

[0053] In a relaxed or slightly preloaded state, the spring element 52 is in contact with the auxiliary piston 50 and the base 36.

[0054] During the operation of the vibration damper 10, when the piston rod 20 moves along the compression direction D, the auxiliary piston rod 42 moves axially toward the auxiliary piston 50 and pushes the auxiliary piston 50 toward the base member 36 along the compression direction D, at which time the spring element 52 is loaded. Subsequently, when the piston rod 20 moves along the tension direction Z, the auxiliary piston is pressed along the tension direction Z by the spring element 52 until it returns to its initial position.

[0055] The damper 10 also includes a damping element 28, which is arranged and designed to dampen the impact of the piston rod 20 (especially the auxiliary piston rod 42) on the auxiliary piston 50 during the compression phase. The damping element 28 is preferably made of an elastic material, such as rubber (especially ECO black rubber) or TEEE (thermoplastic). Exemplarily, the damping element 28 is spherical. It is also contemplated that the damping element 28 be cuboid, cubic, pyramidal, or conical. Other geometries with angular or circular cross-sections may also be used.

[0056] Preferably, the piston rod 20 (especially the auxiliary piston rod 42) has a contact surface 38a for contacting the auxiliary piston 50, which is formed particularly on the end face of the piston rod 20 facing the auxiliary piston 50. The piston rod 20 (especially the auxiliary piston rod 42) has a groove 32 in the contact surface 38a, in which a damping element 28 is disposed. The damping element 28 is preferably fastened in the groove, preferably by form-locking, force-locking and / or material-locking. In particular, the damping element 28 is press-fitted into the groove 32. For example, the groove 32 extends axially relative to the contact surface 38a in the direction toward the main piston 18.

[0057] Preferably, the volume of the groove 32 is greater than the volume of the damping element 28. Preferably, the volume of the damping element 28 is approximately 50% to 95% of the volume of the groove 32, particularly 70% to 90%, and preferably 80%. Preferably, the damping element 28 is designed such that when the piston rod 20 impacts the auxiliary piston 50, the damping element elastically deforms, causing the piston rod 20 to at least partially abut against the auxiliary piston 50 with its front side. In particular, the damping element 28 is designed such that when the piston rod 20 impacts the auxiliary piston 50, the damping element elastically deforms, causing the damping element to be completely contained within the groove 32 and not extend beyond the groove 32 in the axial direction. Preferably, the damping element 28 is designed and arranged such that in a first position where the piston rod 20 and the auxiliary piston 50 are spaced apart, the damping element protrudes axially from the groove 32, and in a second position where the piston rod 20 and the auxiliary piston 50 are in contact, the damping element is completely contained within the groove 32.

[0058] Figure 2 The diagram shows the details based on the enlarged image. Figure 1 One detail of the vibration damping buffer 10, in which, Figure 2 The damper 10 shown is positioned where the piston rod 20 is not in contact with the auxiliary piston 50. Figure 2 Key components and Figure 1 The key components are consistent. Figure 3 A detailed view of an exemplary embodiment of the piston rod 20 is shown, wherein the groove 32 is exemplaryly formed into a cylindrical shape.

[0059] Figure 4a and Figure 4b Another exemplary embodiment of the damping element 28 is shown, wherein the components of the damper 10 are... Figures 1 to 3 The components are basically the same. Figure 4a and Figure 4b The damping element 28 is exemplary in a crown shape. Optionally, the damping element 28 has a surface facing the auxiliary piston 50, which has at least one or more protrusions and recesses. For example, the surface is designed to be wavy. For example, the damping element 28 is designed to be circular, wherein the surface facing the auxiliary piston 50 is wavy. The recess 32 is also designed to be circular. Optionally, the damping element 28 has a reset element (e.g., a wave spring) which is completely disposed inside the damping element 28.

[0060] exist Figure 5 In the position shown, the piston rod 20 moves further along the compression direction D, wherein the auxiliary piston 50 abuts against the contact surface 38a of the piston rod 20 and preferably moves with the piston rod 20 along the compression direction D. At this time, the spring element 52 is loaded, so that it applies a force along the tension direction Z to the auxiliary piston 50, which preferably increases during the movement along the compression direction D. Figure 5 In the position shown, the damping element 28 is exemplaryly arranged entirely within the recess 32, wherein the contact surface 38a abuts against the additional piston 50.

[0061] Figure 6 The auxiliary piston 50 is shown in detail. The auxiliary piston 50 includes a valve body 58 having at least one or more axial through-holes 60 covered by a valve plate 62. The valve plate 62 is attached to the piston rod end of the valve body 58 and preloaded such that when a certain pressure is reached within the compression stage working chamber 56, the valve plate allows (hydraulic fluid) to flow from the compression stage working chamber 56 through the through-holes 60 into the second working chamber 24. Therefore, the through-holes 60 and the valve plate 62 together prevent the pressure within the compression stage working chamber 56 from rising above a certain value.

[0062] The auxiliary piston 50 includes, for example, a piston ring 64 arranged circumferentially around the valve body 58 and particularly movable axially. The piston ring 64 is, for example, circular or cylindrical. The valve body 58 has, for example, a radially outward shoulder 66 at its piston rod end, which forms an axial contact surface for the piston ring 64. The piston ring 64 is designed to seal fluidically relative to the inner wall of the damper tube 14. For example, the piston ring 64 has a through opening 76 through which hydraulic fluid can flow. The auxiliary piston 50 preferably has a plate 68 arranged at the end of the auxiliary piston 50 away from the piston rod, particularly on the valve body 58. The plate 68 preferably extends radially beyond the valve body 58 and forms an axial contact surface for the piston ring 64. The valve body 58, the valve plate 62, and the plate 68 are preferably connected by connecting elements 78 (e.g., screws or rivets, such as those with washers).

[0063] The piston ring 64 is preferably arranged around the valve body 58 such that it can move axially (especially continuously) from a first position to a second position, in which the piston ring abuts against the shoulder 66 of the valve body 58, and in the second position, the piston ring abuts against the plate 68. The valve body 58 preferably has grooves 70 on its outer surface, which are preferably aligned with cutouts 80 in the plate 68 to form a bypass passage 74 between the working chamber 56 during compression and the working chamber 24 away from the piston rod.

[0064] When the auxiliary piston 50 moves along the compression direction D, the piston ring 64 abuts against the shoulder 66 of the valve body 58, at least partially closing the bypass passage 74. At this time, the bypass passage 74 includes a first flow cross-section, which, for example, coincides with the cross-section of the through opening 76 in the piston ring 64. Figure 6 The position of piston ring 64 is shown when the auxiliary piston 50 moves along the stretching direction Z, wherein piston ring 64 abuts against plate 68 and preferably opens bypass channel 74. Figure 6 In the position of piston ring 64 shown, the bypass passage 74 has a second flow cross-section, which is larger than the first flow cross-section. Piston ring 64 is preferably used as a throttling element to adjust the flow cross-section of bypass passage 74.

[0065] The grooves 70 are preferably formed on the radially outward circumferential surface of the valve body 58. For example, the valve body 58 has a plurality of grooves 70, which are equidistant from each other circumferentially. The grooves 70 preferably extend axially from the end of the valve body 58 away from the piston rod to the shoulder 66 of the valve body 58. For example, the grooves 70 are designed as semi-shells with a semi-circular cross-section. The grooves preferably have a circular, partially circular, or angular cross-section. In particular, all the grooves 70 are designed identically.

[0066] Plate 68 preferably has a plurality of slits 80 through which hydraulic fluid can flow. The slits 80 are preferably aligned with grooves 70. In particular, at least a portion of the slits 80 are aligned with through holes 60. A bypass passage 74 is preferably formed by the slits 80 in plate 68, the grooves 70 in valve body 58, and piston ring 64. Plate 68 is, for example, rotatable about the axial central axis of auxiliary piston 50, such that the alignment of the slits 80 relative to through holes 60 and grooves 70 is adjustable and thus allows for changes in the flow cross-section.

[0067] For example, piston ring 64 has a through opening 76 designed as a slot, which forms a complete circumferential interruption of the annular piston ring 64. For example, piston ring 64 has multiple (especially three) through openings 76. Opposite through openings 76 are preferably designed identically. For example, through openings 76 are designed as grooves in the inner wall of piston ring 64 and / or the piston rod side end face.

[0068] For example, the auxiliary piston 50 has a damping element 28. Preferably, either the auxiliary piston 50 or the piston rod 20 has the damping element 28. The damping element 28 is particularly attached to the end face of the auxiliary piston 50 facing the piston rod 20. Preferably, the auxiliary piston has a contact surface 38b facing the piston rod 20 and is designed to contact the piston rod 20 (particularly the contact surface 38a of the piston rod 20). The contact surface 38b preferably forms an end face facing the piston rod 20 and preferably has a groove 32 in which the damping element 28 is disposed. For example, the groove 32 is formed in the connecting element 78. The damping element 28 and the groove 32 are consistent with the embodiment described for the groove 32 and the damping element 28 for the piston rod 20.

[0069] Figure 1 and Figure 5The pressure stop receiver 82 shown is exemplary cylindrical and has a bypass opening 54 that extends through the wall of the pressure stop receiver 82 and forms another bypass for hydraulic fluid between the auxiliary piston 50 and the inner wall of the damper tube 14. For example, the bypass opening 54 extends from the piston rod end of the pressure stop receiver 82 to approximately the axial center of the pressure stop receiver 82. For example, the bypass opening 54 is designed to gradually narrow in the compression direction, such that the flow cross-section of the bypass opening 54 decreases in the compression direction. For example, the pressure stop receiver 82 has two bypass openings 54, which are particularly identical. Preferably, the bypass openings 54 are arranged opposite to each other, particularly offset 180° circumferentially. The bypass openings 54 form another bypass path through which hydraulic fluid flows from the compression stage working chamber 56 between the auxiliary piston 50 and the inner wall of the damper tube 14. The structural design of the bypass opening 54 extending along the compression direction D can, for example, ensure progressive damping of the auxiliary piston in the compression direction, because the flow cross-section of the bypass path decreases as the auxiliary piston 50 moves along the compression direction D.

[0070] For example, the pressure stop receiver 82 includes a plurality of connecting arms 40 formed at the end region of the pressure stop receiver 82 away from the piston rod and pointing axially. The connecting arms 40 are designed to form a form-locking connection with the base member 36, particularly a snap-fit ​​connection. Preferably, the pressure stop receiver 82 has a plurality of connecting arms 40, particularly a plurality of identically designed connecting arms 40, which are equidistant from each other, particularly circumferentially. The connecting arms 40 are reversibly deformable, for example, radially outward, thereby increasing the inner diameter of the pressure stop receiver 82. In particular, the connecting arms 40 have radially inwardly pointing shoulders at their ends away from the piston rod. To connect the pressure stop receiver 82 to the base member 36, the pressure stop receiver is pushed onto the base member 36, at which point the connecting arms 40 undergo reversible deformation and form a form-locking connection, particularly a snap-fit ​​lock, with a region in the base member 36 preferably complementary to the connecting arms 40.

[0071] List of reference numerals

[0072] 10 shock absorbers

[0073] 12 outer tubes

[0074] 14 Vibration damper tube / inner tube

[0075] 16 Compensation Chambers

[0076] 18 working pistons

[0077] 20 piston rod

[0078] 21 First piston rod section

[0079] 22 First working chamber

[0080] 24 Second working chamber

[0081] 26 end caps

[0082] 28 damping elements

[0083] 30 tension stop sleeve

[0084] 32 grooves

[0085] 34 Sealing Components

[0086] 36 base components

[0087] 38a contact surface

[0088] 38b contact surface

[0089] 40 connecting arms

[0090] 42 Additional Piston Rod

[0091] 44 Second piston rod section

[0092] 46 Tension stop

[0093] 48 Pressure Stop Device

[0094] 50 additional pistons

[0095] 52 Spring Components

[0096] 54. Bypass opening in pressure stop receiver

[0097] 56 Compression Stage Working Chamber

[0098] 58 Valve Body

[0099] 60 through hole

[0100] 62 valve plate

[0101] 64 piston rings

[0102] 66 shoulder

[0103] 68 pieces

[0104] 70 grooves

[0105] 74 bypass channels

[0106] 76 through openings

[0107] 78 connecting elements

[0108] 80 incisions

[0109] 82 Pressure Stop Retainer

[0110] Z-tension direction

[0111] D compression direction

Claims

1. A shock absorber (10) for a vehicle, the shock absorber comprising: - Shock absorber tube (14) filled with hydraulic fluid. - Working piston (18), which is connected to piston rod (20) and arranged to reciprocate within damper tube (14), wherein the interior of damper tube (14) is divided by working piston (18) into a first working chamber (22) and a second working chamber (24). - A pressure stop device (48) with an additional piston (50), and - Pressure stop receiver (82), which is installed inside the damper tube (14) to receive an additional piston (50). - Wherein, the additional piston (50) is arranged to move axially within the pressure stop receiver (82) and to separate the compression stage working chamber (56) within the pressure stop receiver (82), and - In this configuration, the auxiliary piston (50) and the piston rod (20) are arranged to move independently of each other. Its features are, A damping element (28) is arranged between the piston rod (20) and the auxiliary piston (50) to dampen the contact between the piston rod (20) and the auxiliary piston (50) during the compression phase.

2. The vibration damper (10) according to claim 1, wherein, The damping element (28) is attached to the piston rod (20) or the auxiliary piston (50).

3. The vibration damper (10) according to any one of the preceding claims, wherein, The piston rod (20) or auxiliary piston (50) has a groove (32) in which the damping element (28) is arranged.

4. The vibration damper (10) according to claim 3, wherein, The volume of the groove (32) is greater than the volume of the damping element (28).

5. The vibration damper (10) according to any one of the preceding claims, wherein, The damping element (28) is made of an elastic material.

6. The vibration damper (10) according to claim 3, wherein, The damping element (28) is designed and arranged such that: in a first position where the piston rod (20) and the auxiliary piston (50) are spaced apart from each other, the damping element protrudes axially from the groove (32), and in a second position where the piston rod (20) and the auxiliary piston (50) are in contact with each other, the damping element is fully arranged within the groove (32).

7. The vibration damper (10) according to any one of the preceding claims, wherein, The damping element (28) is designed to be circular, spherical, cuboid, cubic, pyramidal, cylindrical, or conical.

8. The vibration damper (10) according to claim 3, wherein, The damping element (28) is fixed in the groove (32) by press fitting.

9. The vibration damper (10) according to any one of the preceding claims, wherein, The damping element (28) has a surface having at least one or more protrusions and depressions.

10. The vibration damper (10) according to any one of the preceding claims, wherein, The groove (32) is cylindrical, hemispherical or annular in shape.

11. The vibration damper (10) according to any one of the preceding claims, wherein, A reset element is arranged inside the damping element (28).

12. The vibration damper (10) according to any one of the preceding claims, wherein, The piston rod (20) has a first piston rod section (21) and a second piston rod section (44), the working piston (18) is attached to the first piston rod section (21), the second piston rod section (44) is adjacent to the working piston (18) in the compression direction (D), and the damping element (28) is attached to the second piston rod section.

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