shock absorbers

Abstract

The invention relates to a shock absorber comprising a cylinder (1, 6) filled with a fluid and a piston rod (3, 7) guided therein, wherein the piston rod (3) is guided into or through the cylinder (1, 6) and is provided with two pistons (41, 73, 76) spaced apart from each other, in which axial bores (42, 74) are provided circumferentially radially spaced from the piston rod (3, 7) and on the outside of each of which a sealing disc (43, 75) for closing the axial bores (42, 74) of the associated piston (41, 73, 76) is axially movably mounted on the piston rod (3, 7), wherein the inner wall of the cylinder encompassing the pistons (41, 73, 76) has at least in certain regions a diameter that changes continuously in the axial direction, wherein at least one pressure equalization element (5, 5', 5'', 5'''') is arranged, which has a pressure-dependent variable volume and is in contact with the fluid.

Description

[0001] The invention relates to a shock absorber, in particular for wheeled vehicles, according to the preamble of patent claim 1.

[0002] Shock absorbers are used, for example, in the chassis of wheeled vehicles in conjunction with a suspension system to dampen vibrations of the sprung mass and thus quickly dissipate them. The more accurate term would be "vibration damper," since it is not the shock itself that is influenced, but its effect. Shock absorbers are not designed to absorb shocks transmitted to the vehicle from uneven road surfaces; that is the responsibility of the suspension. Shock absorbers dampen vibrations of the vehicle body on the suspension system, as well as vibrations of the wheels on the tire suspension. Shock absorbers are also used in a wide variety of applications, for example, to dampen vibrations of machines or machine parts, but also, for example, in furniture construction to dampen flap movements.

[0003] In vehicles, the primary function of a spring within the suspension is to counteract the mass of the vehicle body and the rider. Coil springs are regularly used in two-wheeled vehicles. The spring force of a coil spring generally has a linear progression relative to the compressed travel. At the beginning of a load, the spring is at rest and supports the weight of the vehicle and rider. A low spring constant (spring rate) ensures a comfortable ride. During the suspension travel, the spring force increases. A low and comfortable spring constant, however, allows bottoming out quickly and easily. A high spring constant, on the other hand, reduces bottoming out but impairs ride comfort. Light to moderate shocks caused by uneven road surfaces are less absorbed by a higher spring constant and are transmitted via the vehicle to the rider.The negative spring travel (rebound) is determined by the weight of the rider and vehicle. Further deflection (compression) is determined by the impact of road surface irregularities. The rider's weight can be adjusted by adjusting the coil spring preload.

[0004] By designing a shock absorber in both the rebound and compression directions, driving dynamics and thus ride comfort can be influenced. In the rebound stage of a shock absorber, the vehicle's suspension is damped during the relaxation process within a vibration. In the compression stage, the spring deflection speed is damped.

[0005] Shock absorbers in the automotive sector are usually hydraulic telescopic shock absorbers. These are based on the principle that the resistance to the flow of displaced oil depends on the flow velocity. In the shock absorber, hydraulic oil is forced through narrow bores and valve systems via a piston. The damping force, which counteracts the damper speed, increases progressively with increasing compression and rebound speed of the piston.

[0006] A disadvantage of previously known hydraulic shock absorbers (which, as explained above, are actually vibration dampers) is that, in a spring-damper arrangement, they impair the shock-absorbing effect of the spring in its freely oscillating central region due to their vibration damping. The degree of impairing this effect depends on the piston speed.

[0007] To overcome this problem, DE 20 2023 102 485 U1 presents a shock absorber in which any impairment of the shock absorption effect of an arranged suspension in its freely vibrating central region is avoided. For this purpose, a piston rod is arranged in a cylinder which extends through the cylinder and is provided with two spaced-apart pistons into which axial bores are formed circumferentially and radially spaced from the piston rod. On the respective outer side of the piston, a closing disc for closing the axial bores of the associated piston is mounted axially movably on the piston rod. The inner wall of the cylinder has, at least in some regions, a diameter which changes continuously in the axial direction, thereby causing travel-dependent damping, which enables vibration damping in the freely vibrating central region of a suspension to be minimized.This shock absorber has proven itself in practice and for the first time enables travel-dependent damping with a largely undamped zero position.

[0008] However, when using such a shock absorber, it has been shown that changes in the damping behavior can occur when the shock absorber is subjected to high loads.

[0009] The invention aims to remedy this situation. The invention is based on the object of providing a shock absorber of the above-mentioned type that exhibits essentially consistent damping behavior even under high loads. According to the invention, this object is achieved by a shock absorber having the features of the characterizing part of patent claim 1.

[0010] Surprisingly, it has been shown that a high load causes an increase in the fluid temperature within the cylinder. Due to the incompressibility of the fluid, in this case a hydraulic oil, this results in a pressure increase within the cylinder, which is the cause of the change in the damping behavior. The fact that at least one pressure compensation element is arranged in the cylinder, which has a pressure-dependent variable volume and is in contact with the fluid, counteracts an increase in pressure within the cylinder in the event of a temperature increase of the fluid, in particular a hydraulic oil. In the event of a pressure increase, the pressure compensation element is compressed, releasing additional volume within the cylinder, which leads to pressure equalization. In this way, the pressure in the cylinder is kept constant by the pressure compensation element.

[0011] In a further development of the invention, the at least one pressure compensation element is made of elastomer foam, foam rubber, or cellular rubber. These materials have cavities that are compressed under external pressure, thereby reducing the volume of the pressure compensation element.

[0012] In one embodiment of the invention, a pressure compensation element is arranged between the two pistons, at least partially surrounding the piston rod. This provides an alternative or additional pressure compensation volume.

[0013] In a further embodiment of the invention, at least two radially projecting support elements are arranged at a distance from one another between the pistons, between which at least one pressure compensation element is held. The support elements hold the pressure compensation element in position, allowing the hydraulic fluid to flow unhindered during operation.

[0014] In a further development of the invention, the cylinder inner wall is formed by the inner surface of at least one damper sleeve introduced into the cylinder, the outer diameter of which is smaller than the inner diameter of the cylinder. At least one pressure compensation element is arranged in the jacket gap formed between the cylinder and the at least one damper sleeve, and the jacket gap can be supplied with fluid via at least one passage opening. This provides a pressure compensation volume running along the cylinder wall as the fluid pressure increases. The pressure compensation element is compressed by hydraulic fluid flowing in through the passage opening and having an overpressure, thereby compensating for the overpressure.

[0015] In one embodiment of the invention, the cylinder is closed at one end, with the piston rod protruding from the other end. A piston guide is arranged between the two pistons, which has at least one pressure equalization opening. This allows for a space-saving damper design. The piston guide ensures linear guidance of the double piston and the piston rod.

[0016] At the same time, pressure equalization between the two pistons can take place through at least one pressure equalization opening.

[0017] In a further embodiment of the invention, at least one damper sleeve forming the cylinder's inner wall is arranged in the cylinder on each side of the piston guide, each of which forms a jacket gap in which a pressure compensation element is arranged. As a result, a pressure-dependent variable volume for pressure compensation is arranged on both sides. Preferably, the two jacket gaps formed by the two damper sleeves are of different widths, with the second gap facing the closed end of the cylinder preferably being wider than the first gap facing the open end of the cylinder.

[0018] In one embodiment of the invention, the size of the pressure compensation element essentially corresponds to the size of the gap. This achieves a maximum pressure-dependent variable volume.

[0019] In a further embodiment of the invention, at least one damper sleeve is formed from two successively arranged damper sub-sleeves, each having a different inner contour. This results in a damper sleeve structure composed of different damper sub-sleeves, allowing for a wide variety of configurations of the inner contour of the damper sleeve.

[0020] In a further development of the invention, the piston rod is constructed in several parts. This simplifies assembly.

[0021] In a refinement of the invention, the cylinder inner wall has a first region that widens conically in the axial direction and a second region that tapers conically. This achieves a travel-dependent damping behavior. Preferably, both pistons have an axially conically tapered section on their outer side facing the respective closure disc.

[0022] In a further embodiment of the invention, the damper sleeve is made of plastic, preferably a thermoplastic, in particular polycarbonate or polyamide. This enables cost-effective production, particularly using an injection molding process.

[0023] The application area of ​​the shock absorber according to the invention is not limited to vehicles, and in particular not to two-wheeled vehicles. Rather, other fields of application also arise, such as vibration damping in machinery or in furniture construction. Use in the construction industry, for example, for tall buildings or earthquake-resistant buildings, is also conceivable.

[0024] Further developments and refinements of the invention are specified in the remaining subclaims. Exemplary embodiments are illustrated in the drawings and described in detail below. They show: Fig. 1: the schematic representation of a shock absorber a) in a side view; b) in a transparent presentation; c) in longitudinal section; Fig. 2: the representation of the shock absorber from Fig. 1 in exploded view; Fig. 3: the schematic representation of a shock absorber in a second embodiment a) in a side view; b) in a transparent presentation; c) in longitudinal section; Fig. 4: the schematic representation of a shock absorber in a third embodiment a) in a side view; b) in a transparent presentation; c) in longitudinal section; Fig. 5: the schematic representation of a modular damper sleeve for use in the cylinder of a shock absorber and Fig. 6: The representation of the damping performance characteristics of a shock absorber within a compression-tension cycle at elevated fluid temperature with and without pressure compensation element.

[0025] The example shown in Fig. 1 comprises a cylinder 1 filled with a fluid, in this case hydraulic oil, into which a damper sleeve 2 is inserted, through which a piston rod 3 is slidably guided. Arranged on the piston rod 3 is a piston module 4 which is formed from two pistons 41 connected to one another via a spacer 40, which pistons are provided with axial bores 42 and on whose outward-facing side a closing disk 43 is axially displaceably mounted on the piston rod 3. Between the two pistons 41, two support disks 44 are arranged on the spacer 40 at a distance from one another, between which support disks a pressure compensation element 5 is held. In the exemplary embodiment, the pressure compensation element 5 is hollow cylindrical and made of foam rubber.

[0026] The cylinder 1 comprises a cylinder tube 11, which is closed at each end by a sealing and guide assembly 12, which is sealed to the cylinder tube 11 by an O-ring 13 and sealed to the radially and axially movable piston rod 3 by a hydraulic sealing ring 14. The sealing and guide assemblies 12 are each axially fixed in the cylinder tube 11 by a closure piece 15. The damper sleeve 2 is axially held in the cylinder tube 11 between the sealing and guide assemblies 12 arranged on both sides.

[0027] In the exemplary embodiment, the damper sleeve 2 is composed of three damper sleeve parts 21, 22, 23, which are made of a thermoplastic material, in this case polyamide, and whose individual inner contours complement each other to form the effective inner contour of the damper sleeve 2. The damping behavior of the shock absorber can be adjusted by adjusting the inner contour of the damper sleeve 2.

[0028] The outer diameter of the damper sleeve 2 is approximately 2 percent smaller than the inner diameter of the cylinder tube 11, creating a jacket gap 16 between the cylinder tube 11 and the damper sleeve 2. The damper sleeve 2 is thus axially fixed and held in a floating manner within the cylinder tube 11.

[0029] The piston rod 3 comprises two piston rod pieces 31, 32, which are screwed to the piston module 4. For this purpose, the piston module 4 in the exemplary embodiment has axial threaded blind bores at both ends, into which a piston rod piece 31, 32 is screwed with an external thread provided for this purpose at the end. Alternatively, a threaded rod can also be arranged, which is guided through an axial through-bore provided in the piston module 4 and to which the two piston rod pieces 31, 32 are screwed. The two piston rod pieces 31, 32 also have, on their side facing the piston module 4, a reduced-diameter shoulder 33, which extends up to the respective piston 41 and on which a respective closure disc 43 is mounted for axial displacement.

[0030] The second piston rod piece 32 further has, at its end opposite the piston module 4, a connecting pin 34 for connection to a connecting rod of a spring module to form a spring-damper system.

[0031] The piston module 4 consists of two pistons 41 that are connected to one another via a cylindrical spacer 40. The pistons 41 are essentially identical in design and have a cylindrical section 411, which is adjoined by a conically tapered section 412. The pistons 41 are arranged opposite one another, pivoted by 180 degrees, so that the tapered section 412 is directed outward in each case. Axial bores 42 are formed in the pistons 41, radially spaced from the spacer 40 and regularly spaced from one another.

[0032] Two support discs 44 are arranged at a distance from one another on the spacer 40, the outer diameter of which is smaller than the outer diameter of the pistons 41. A pressure compensation element 5 is held between the support discs 44. In the exemplary embodiment, the pressure compensation element 5 is hollow-cylindrical and made of foam rubber. The outer diameter of the pressure compensation element 5 essentially corresponds to the outer diameter of the support discs 44.

[0033] When the piston rod 3 moves in the tensile direction (tensile load), the fluid in the cylinder 1 is compressed by the first piston 41, which is at the front in the direction of movement. As a result, the closing disc 43 arranged in front of the first piston 41 is pressed against the first piston 41, whereby the axial bores 42 located in the first piston 41 are closed. The fluid is pressed through the annular gap formed between the cylindrical section 411 of the first piston 41 and the inner wall of the damper sleeve 2. The conical section 412, which tapers axially towards the closing disc 43, assists the flow of the fluid into the annular gap. The inner diameter of the damper sleeve 2, which changes in the axial direction, results in a width of the annular gap formed between the first piston 41 and the inner wall of the damper sleeve 2 that changes over the travel, thereby resulting in damping that changes over the travel.The fluid can then flow unhindered through the axial bores 42 of the second piston 41, with the associated closure disc 43 being forced away from this second piston 41 by the fluid. The second piston 41 is positioned here in the region of the maximum inner diameter of the damper sleeve 2 composed of the three damper sleeve parts 21, 22, 23, so that the annular gap formed between the second piston 41 and the inner wall of the damper sleeve 2 has a maximum width through which the fluid can flow. The inner contour of the damper sleeve 2 determines the damping effect of the shock absorber over its travel.

[0034] When the piston rod 3 moves in the compression direction, the above process is reversed, with the fluid in the cylinder 1 now being compressed again by the piston 41 at the front in the direction of movement and being pressed through the annular gap formed between the cylindrical section 411 of this piston 41 and the inner wall of the damper sleeve 2.

[0035] As the load on the shock absorber 1 increases due to vibrations of the piston rod 3 equipped with the piston module 4, the fluid in the cylinder 1 heats up, causing it to expand. This expansion causes an increase in the fluid pressure, in this case, of hydraulic oil. The increasing pressure of the hydraulic oil, which also applies to the pressure compensation element 5, compresses it. This increases the effective volume of the cylinder tube 11, thereby reducing the fluid pressure again.

[0036] If the fluid temperature subsequently drops again, the pressure of the fluid applied to the pressure compensation element 5 decreases, causing the pressure compensation element 5 to expand again. The resulting reduction in the effective volume of the cylinder tube 1 again equalizes the fluid pressure. In this way, the pressure compensation element 5 prevents a change in the damper performance characteristics due to a rise in the fluid temperature.

[0037] In Fig. Figure 6 compares the characteristics of the shock absorber according to the invention (measurement curve b) with an identical shock absorber without a pressure compensation element (measurement curve a). As can be seen there, the deviation from the zero-force line caused by the increased fluid temperature in measurement curve a of the shock absorber without a pressure compensation element is eliminated in measurement curve b of the shock absorber according to the invention with the pressure compensation element.

[0038] In the shock absorber chosen as a further embodiment according to Fig. 3, a damper sleeve 2' is inserted into the cylinder tube 11 of the cylinder 1. The damper sleeve 2' is formed from two damper sleeve parts 21', 22', each having a circumferential collar 24 at its end. A hollow-cylindrical pressure compensation element 5' is applied to each of the damper sleeve parts 21', 22', the height of which essentially corresponds to the height of the circumferential collar 24. Recesses are made in the end faces and in the inner, adjacent collars 24 of the adjacent damper sleeve parts 21', 22', forming a channel through which the two pressure compensation elements 5' are connected to the interior space defined by the damper sleeve 2'. The two pressure compensation elements 5' are thus constantly supplied with fluid. The functioning of the shock absorber essentially corresponds to the functioning of the first exemplary embodiment described above.

[0039] If the fluid in cylinder 1 heats up, it expands, which in turn causes an increase in fluid pressure. Due to the increasing pressure of the fluid applied to the pressure compensation elements 5' arranged in the jacket gap, these are compressed, whereby the effective volume of the cylinder tube 11 is increased. This in turn reduces the fluid pressure. If the fluid temperature subsequently drops again, the pressure of the fluid applied to the pressure compensation elements 5' drops, causing the pressure compensation elements 5' to expand again. This reduces the effective volume of the cylinder tube 11 again, whereby the fluid pressure is again equalized.

[0040] In order to keep the width of the jacket gap accommodating the pressure compensation elements 5' small, the spacer 40 arranged between the two pistons 41 of the piston module 4 can be used in an analogous manner to the embodiment in Fig. 1 a further pressure compensation element 5 may be applied.

[0041] The shock absorber chosen as the third embodiment according to Fig. 4 comprises a cylinder 6 filled with a fluid, in this case hydraulic oil, with a cylinder tube 61 closed at one end by a sealing and guide package 62, which is sealed against a radially and axially movable piston rod 7 by a hydraulic sealing ring 63. The sealing and guide package 62 is axially fixed in the cylinder tube 61 by a closure piece 64. At its end opposite the closure piece 64, the cylinder tube 61 is closed by a plug 65. Between the closure piece 64 and the plug 65, a support ring 66 is arranged in the cylinder tube 61 as a piston guide. The support ring is provided with axial bores 67 and through which the piston rod 7 is guided.

[0042] The piston rod 7 is composed of a first piston rod section 71 and a second piston rod section 72, which are screwed together and between which a first piston 73 is held. A closure disc 75 is held axially displaceably on the first piston rod section 71. An end piece 77 is screwed onto the end of the second piston rod section 72, on which another closure disc 75 is guided axially displaceably. A second piston 76 is held between the second piston rod section 72 and the end piece 77, which in the exemplary embodiment has a smaller outer diameter than the first piston 73. The two pistons 73, 76 are in turn provided with axial bores 74.

[0043] A split damper sleeve 8 is arranged in the cylinder tube 61. It is made of a thermoplastic material, in this case polyamide, and is formed from four damper sleeve parts 81, 82, 84, 85, whose individual inner contours complement each other to form the effective inner contour of the damper sleeve 8. Positioned between the sealing and guide assembly 62 and the support ring 66 is a first damper sleeve assembly comprising two adjacent damper sleeve parts 81, 82, each of which has a circumferential collar 83 at its end. A first, hollow-cylindrical pressure compensation element 5" is arranged between the collar 83 of the damper sleeve part 81 resting against the sealing and guide package 62, the height of which substantially corresponds to the height of the collar 83. A second damper sleeve arrangement is formed from two further adjacent damper sleeve parts 84, 85 and is positioned between the support ring 66 and the plug 65.The damper sleeve parts 84, 85 also each have a circumferential collar 86 at their ends.

[0044] A second, hollow-cylindrical pressure compensation element 5''' is arranged between the collars 86 of the damper sleeve part 85 resting against the plug 65, the height of which substantially corresponds to the height of the collar 86. The height of the collars 86 and of the pressure compensation element 5''' is selected to be greater than the height of the collars 83 and of the pressure compensation element 5''. The space required for this is provided by the smaller outer diameter of the second piston 76 compared to the first piston 73. With the exception of the collars 83, 86 resting against the sealing and guide package 62 and the plug 65, all collars 83, 86 are provided with recesses around their circumference, forming channels that are connected to radial bores 68 that are circumferentially introduced into the support ring 66 and open into the axial bores 67. As a result, the pressure compensation elements 5'', 5''', which in the exemplary embodiment are made of foam rubber, are continuously supplied with hydraulic oil.

[0045] The functioning of this shock absorber, in particular the piston 73 provided with axial bores 74 in interaction with the closure discs 75 and with the inner contour of the damper sleeve 8, essentially corresponds to the functioning of the previously described shock absorbers, with the difference that the piston rod is led out of the cylinder 6 only on one side and is guided by a support ring 66 arranged in the cylinder tube 61 and acting as a piston guide.

[0046] This configuration results in an additional, significant change in the effective volume of the cylinder tube 61 upon movement of the piston rod 7 with the pistons 73, 76 arranged thereon, which leads to a negative or positive pressure of the fluid, which in turn would impede or even block the movement of the piston rod 7. This additional volume change is compensated by the pressure compensation elements 5''', which are larger than in the previous embodiments.

[0047] If the pressure of the fluid (in this case hydraulic oil) acting on the pressure compensation elements 5'', 5''' arranged in the jacket gaps formed by the damper sleeve parts 81, 85 and the cylinder tube 61 increases due to movement of the piston rod 7 as well as due to an increase in the fluid temperature, the pressure compensation elements 5'', 5''' are compressed, whereby the effective volume of the cylinder tube 11 accessible to the fluid is again increased, thereby reducing the fluid pressure. If the fluid pressure acting on the pressure compensation elements 5'', 5''' decreases due to an opposite movement of the piston rod 7 as well as due to a decrease in the fluid temperature, the pressure compensation elements 5'', 5''' expand again. This reduces the effective cylinder tube volume again, whereby the fluid pressure is equalized again. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2023 102 485 U1

[0007]

Claims

[1] Shock absorber, comprising a cylinder (1, 6) filled with a fluid and a piston rod (3, 7) guided in the cylinder, wherein the piston rod (3) is guided into the cylinder (1, 6) or through it and is provided with two pistons (41, 73, 76) spaced apart from one another, into which axial bores (42, 74) are introduced circumferentially and radially spaced from the piston rod (3, 7), and on the outside of which a closure disc (43, 75) for closing the axial bores (42, 74) of the associated piston (41, 73, 76) is mounted axially movably on the piston rod (3, 7), wherein the inner cylinder wall surrounding the pistons (41, 73, 76) has, at least in some regions, a diameter that changes continuously in the axial direction, characterized by that at least one pressure compensation element (5, 5', 5'', 5''') is arranged in the cylinder (1, 6), which has a pressure-dependent variable volume and which is in contact with the fluid. [2] Shock absorber according to claim 1, characterized by that the at least one pressure compensation element (5, 5', 5'', 5''') is made of elastomer foam, foam rubber or cellular rubber. [3] Shock absorber according to claim 1 or 2, characterized by that a pressure compensation element (5) is arranged between the two pistons (41) surrounding the piston rod (3) at least in some areas. [4] Shock absorber according to claim 3, characterized by that between the pistons (41) there are at least two radially projecting support elements (44) arranged at a distance from one another, between which at least one pressure compensation element (5) is held. [5] Shock absorber according to one of the preceding claims, characterized byin that the cylinder inner wall is formed by the inner surface of at least one damper sleeve (2, 8) introduced into the cylinder (1, 6), the outer diameter of which is smaller than the inner diameter of the cylinder (1, 6), wherein at least one pressure compensation element (5', 5'', 5''') is arranged in the jacket gap formed between the cylinder (1, 6) and the at least one damper sleeve (2, 8), and wherein the jacket gap can be acted upon by the fluid via at least one passage opening. [6] Shock absorber according to one of the preceding claims, characterized by that the cylinder (6) is closed at one end, the piston rod (7) protruding from the other end therefrom and a piston guide (66) having at least one pressure equalization opening (67) is arranged between the two pistons (73, 76). [7] Shock absorber according to claim 6, characterized bythat in the cylinder (6) on each side of the piston guide (66) at least one damper sleeve (81, 85) forming the cylinder inner wall is arranged, through each of which a jacket gap is formed in which a pressure compensation element (5'', 5''') is arranged. [8] Shock absorber according to claim 7, characterized by that the two jacket gaps formed by the two damper sleeves (81, 85) are of different widths, wherein preferably the second gap facing the closed end of the cylinder (6) is wider than the first gap facing the open end of the cylinder (6). [9] Shock absorber according to one of claims 5 to 8, characterized by that the size of the pressure compensation element (5'', 5''') essentially corresponds to the size of the gap. [10] Shock absorber according to one of claims 5 to 9, characterized bythat at least one damper sleeve (2, 8) is formed from at least two damper part sleeves (21, 22, 23, 81, 82, 84, 85) arranged one behind the other, which have a different inner contour to one another. [11] Shock absorber according to one of the preceding claims, characterized by that the piston rod (3, 7) is designed in several parts. [12] Shock absorber according to one of the preceding claims, characterized by that the cylinder inner wall has a conically widening area in the axial direction in a first area and a conically tapering area in a subsequent second area. [13] Shock absorber according to one of the preceding claims, characterized by that the damper sleeve (2, 8) is made of plastic, preferably of a thermoplastic plastic, in particular of polycarbonate or polyamide. [14] Shock absorber according to one of the preceding claims, characterized bythat the two pistons (41, 73, 76) have an axially conically tapered section on their outer side facing the respective closure disc (43, 75).

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