Improved structure of hydraulic shock absorber and hydraulic shock absorber thereof

Abstract

The utility model provides an improved structure of a hydraulic shock absorber and the hydraulic shock absorber thereof, and the improved structure of the hydraulic shock absorber comprises a compression cylinder located in the hydraulic shock absorber; the piston rod is connected to a piston of the hydraulic shock absorber, and the piston rod can be in sealing sliding fit with the compression cylinder; and the retaining structure is arranged at the end part of the piston rod in a sleeving manner, and the retaining structure can be rotatably sealed between the inner wall of the compression cylinder and the piston rod. According to the improved structure of the hydraulic shock absorber and the hydraulic shock absorber thereof, the compression chamber is used at the tail end of the compression stroke, so that the problem that damping force is increased when the compression stroke of the shock absorber is finished is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydraulic brake technical field especially relates to an improved structure of hydraulic shock absorber and hydraulic shock absorber thereof. BACKGROUND

[0002] The description in this section merely provides background information related to the present disclosure and does not constitute the prior art.

[0003] Currently, in the field of mechanical engineering, the hydraulic compression stop system is a device for controlling the movement and vibration of mechanical equipment. The traditional hydraulic compression stop system usually uses the position and speed of the piston rod to generate a predetermined damping force to control the movement of the equipment. However, with the development of technology, the market demand for systems capable of generating progressive damping force increase is increasing.

[0004] It should be noted that the above introduction to the technical background is only to facilitate a clear and complete description of the technical scheme of the present utility model, and to facilitate the understanding of the skilled in the art. The above technical scheme cannot be considered as known to the skilled in the art only because it is described in the background section of the present utility model. SUMMARY

[0005] The utility model aims at providing an improved structure of hydraulic shock absorber and hydraulic shock absorber thereof, which uses a compression chamber at the end of the compression stroke to solve the problem of the additional force generated at the end of the compression stroke affecting the performance of the standard valve.

[0006] The above implementation purposes of the utility model are mainly realized by the following technical scheme:

[0007] The utility model provides an improved structure of hydraulic shock absorber, which comprises an outer cylinder and a piston movably arranged in the outer cylinder, and further comprises a compression sealing mechanism capable of providing progressive damping force, wherein the compression sealing mechanism has:

[0008] A compression cylinder is located in the outer cylinder.

[0009] A piston rod is connected to the piston, and the piston rod can be sealingly and slidably matched with the compression cylinder.

[0010] A retaining structure is sleeved on the end of the piston rod, and the retaining structure is rotatably sealed between the inner wall of the compression cylinder and the piston rod.

[0011] According to an embodiment of the utility model, the retaining structure comprises a sealing ring and an open sealing ring stacked together, the end of the piston rod is formed with a convex column, and the sealing ring and the open sealing ring are sleeved on the convex column and are limited on the convex column by a retaining piece.

[0012] According to one embodiment of the utility model, the opening sealing ring is formed with a notch, and the notch and the opening of the opening sealing ring are oppositely arranged along the diameter direction of the opening sealing ring.

[0013] According to one embodiment of the utility model, the inner diameter of the sealing ring and the inner diameter of the opening sealing ring are the same, and both are greater than the outer diameter of the convex column.

[0014] According to one embodiment of the utility model, the end face of the sealing ring and the opening sealing ring is formed with a centering structure capable of cooperating with each other.

[0015] According to one embodiment of the utility model, the centering structure includes a first inclined surface formed on the end face of the sealing ring and a second inclined surface formed on the end face of the opening sealing ring, the first inclined surface is arranged radially outwardly in the direction away from the opening sealing ring, and the second inclined surface is arranged radially outwardly in the direction away from the sealing ring.

[0016] According to one embodiment of the utility model, the inclination angle of the first inclined surface is the same as the inclination angle of the second inclined surface.

[0017] According to one embodiment of the utility model, the sealing ring is convexly provided with an insertion ring in the direction of the opening sealing ring, and the insertion ring can extend into the opening sealing ring.

[0018] According to one embodiment of the utility model, the retaining structure is a spring sealing ring, the end of the piston rod is formed with a convex column, and the spring sealing ring is sleeved on the convex column.

[0019] According to one embodiment of the utility model, the retaining structure is a sealing ring formed by sequentially splicing a plurality of arc-shaped pieces, the arc-shaped pieces are connected by elastic pieces, the end of the piston rod is formed with a convex column, and the sealing ring is sleeved on the convex column.

[0020] According to one embodiment of the utility model, the elastic piece is located between the sealing ring and the convex column.

[0021] According to one embodiment of the utility model, the inner wall of the compression cylinder is provided with a damping groove extending in the axial direction thereof, and the damping groove is arranged extending from the opening of the compression cylinder to the bottom of the compression cylinder.

[0022] According to one embodiment of the utility model, the damping groove is a plurality of, and the plurality of damping grooves are arranged at intervals along the circumferential direction of the compression cylinder.

[0023] The utility model also provides a hydraulic shock absorber, including the outer tube and the piston of movably arranged in the outer tube, the hydraulic shock absorber still includes the improved structure of hydraulic shock absorber as above-mentioned, the improved structure is located in the hydraulic shock absorber.

[0024] Compared with the prior art, the technical scheme has the following characteristics and advantages:

[0025] The improved structure of the hydraulic shock absorber and the hydraulic shock absorber have the advantages that the compression sealing mechanism is added to the end of the compression stroke of the piston in the outer tube, a plurality of damping grooves are arranged on the inner wall of the compression cylinder of the compression sealing mechanism, the damping force increasing gradual characteristic can be adjusted and obtained, the excessive force of the hydraulic shock absorbing system can be avoided to damage the vehicle parts, and the structure makes the hydraulic shock absorbing system can produce the damping force of gradual increase. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the sectional view of the improved structure of the hydraulic shock absorber of the utility model.

[0027] Figure 2 It is the sectional view of the piston rod of the improved structure of the hydraulic shock absorber of the utility model and the compression cylinder.

[0028] Figure 3 It is Figure 2 The enlarged view of A part in the Fig.

[0029] Figure 4 It is the structure schematic view of the opening sealing ring of the utility model.

[0030] Figure 5 It is the bottom view sectional view of the improved structure of the hydraulic shock absorber of the utility model, wherein the gap orientation between the sealing ring and the compression cylinder is shown and is arranged in the position of the cylinder wall of the holding structure closer to the compression cylinder.

[0031] Figure 6 It is the bottom view sectional view of the improved structure of the hydraulic shock absorber of the utility model, wherein the gap orientation between the sealing ring and the compression cylinder is shown and is arranged in the position of the cylinder wall of the holding structure away from the compression cylinder.

[0032] Figure 7 It is the explosion view of the improved structure of the hydraulic shock absorber of the utility model.

[0033] Figure 8 It is the front view of the first embodiment of the holding structure of the improved structure of the hydraulic shock absorber of the utility model.

[0034] Figure 9 It is the bottom view of the holding structure of the improved structure of the hydraulic shock absorber of the utility model and has the first embodiment. Figure 1 .

[0035] Figure 10 The bottom view of the retaining structure with the first embodiment of the improved structure of the hydraulic shock absorber of the utility model Figure 2 .

[0036] Figure 11 The perspective view of the sealing ring of the retaining structure of the second embodiment of the improved structure of the hydraulic shock absorber of the utility model

[0037] Figure 12 The sectional view of the retaining structure of the third embodiment of the improved structure of the hydraulic shock absorber of the utility model

[0038] Figure 13 The perspective view of the retaining structure with the fourth embodiment of the improved structure of the hydraulic shock absorber of the utility model

[0039] Figure 14 The front view of the fifth embodiment of the retaining structure of the improved structure of the hydraulic shock absorber of the utility model

[0040] BRIEF DESCRIPTION OF DRAWINGS

[0041] 1, outer cylinder; 2, piston; 3, improved structure of hydraulic shock absorber; 31, compression cylinder; 311, damping groove; 32, piston rod; 321, convex column; 33, retaining structure; 331, sealing ring; 3311, insertion ring; 3312, first inclined surface; 332, open sealing ring; 3321, opening part; 3322, notch; 3323, second inclined surface; 333, arc-shaped piece; 334, elastic piece; 34, retaining piece; 4, adapter seat; 5, centering structure; F1, axis; F2, axis; C1, gap. DETAILED DESCRIPTION

[0042] In order to make the person skilled in the art better understand the technical scheme in the utility model, the technical scheme in the utility model embodiments will be described clearly and completely below in conjunction with the drawings in the utility model embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the utility model.

[0043] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] Implementation Method 1

[0046] like Figure 1 As shown, this utility model provides an improved structure 3 for a hydraulic shock absorber, including a compression cylinder 31, a piston rod 32, and a retaining structure 33. The compression cylinder 31 is located inside the hydraulic shock absorber; the piston rod 32 is connected to the piston 2 of the hydraulic shock absorber, and the piston rod 32 can be sealed and slidably engaged with the compression cylinder 31; the retaining structure 33 is sleeved on the end of the piston rod 32, and the retaining structure 33 can be rotatably sealed between the inner wall of the compression cylinder 31 and the piston rod 32.

[0047] The improved structure of the hydraulic shock absorber of this utility model is configured at the end of the piston compression stroke inside the outer cylinder 1 to adjust and obtain a gradual increase in damping force, thereby avoiding excessive force generated by the hydraulic shock absorber system and damaging vehicle parts. The improved structure of the hydraulic shock absorber enables the hydraulic shock absorber system to generate a gradually increasing damping force.

[0048] Specifically, such as Figure 1 As shown, the hydraulic shock absorber has an outer cylinder 1 and a piston 2 movably disposed within the outer cylinder 1. The outer cylinder 1 is generally cylindrical, but its shape can be designed in other ways depending on actual needs; this application does not impose any limitations on this. The piston 2 is movably disposed within the outer cylinder 1. In practical applications, one end of the piston 2 extending out of the outer cylinder 1 is used to connect to external mechanical equipment. For example, the improved structure of this hydraulic shock absorber can be used to control the vibration or movement of external mechanical equipment.

[0049] The piston rod 32 is detachably connected to the end of the piston 2 extending into the outer cylinder 1, for example, a lug is formed at the end of the piston 2 extending into the outer cylinder 1, and a connecting groove is formed at the corresponding end of the piston rod 32, and the piston 2 is inserted into the connecting groove of the piston rod 32 through the lug to achieve detachable connection of the two, of course, in other embodiments, the piston rod 32 and the piston 2 can also be connected in a threaded connection manner, or the piston rod 32 and the piston 2 can be integrally formed, which is not limited herein.

[0050] The bottom of the compression cylinder 31 is connected to the compression stroke end of the outer cylinder 1 through the adapter 4, and the opening of the compression cylinder 31 opposite to the bottom of the compression cylinder 31 is arranged opposite to the piston rod 32. The retaining structure 33 is sleeved on the end of the piston rod 32, and the piston rod 32 can move reciprocatingly in the compression cylinder 31 during the reciprocating movement of the piston 2 in the outer cylinder 1, and the retaining structure 33 can be slidably attached to the inner wall of the compression cylinder 31. In the utility model, the inner wall of the compression cylinder 31 is provided with a plurality of damping grooves 311, the damping grooves 311 are arranged extending along the axis direction of the compression cylinder 31, and extend from the opening of the compression cylinder 31 to the bottom of the compression cylinder 31, and the plurality of damping grooves 311 are arranged spaced apart along the circumferential direction of the compression cylinder 31, and the plurality of damping grooves 311 can adjust and obtain the progressive characteristic of the increased damping force. Further, in order to obtain the precise increase of the damping force, in the embodiment, the groove width of the damping groove 311 can be gradually narrowed from the opening of the compression cylinder 31 to the bottom of the compression cylinder 31.

[0051] As shown in Figure 2 and Figure 3 , the inventor finds that the axis F1 of the piston rod 32 connected to the piston 2 deviates from the axis F2 of the compression cylinder 31 located in the outer cylinder 1 during the movement of the piston 2 in the outer cylinder 1, and when this misalignment problem occurs, the hydraulic shock absorption system will be subjected to various forces, thereby affecting the normal operation of the shock absorber. In order to solve this problem, the inventor improves the retaining structure 33.

[0052] According to one feasible embodiment of the utility model, the retaining structure 33 comprises a sealing ring 331 and an open sealing ring 332 stacked together, the end of the piston rod 32 is formed with a lug 321, and the sealing ring 331 and the open sealing ring 332 are sleeved on the lug 321 and are limited on the lug 321 by the retaining piece 34.

[0053] Specifically, as shown in Figure 4 , the open sealing ring 332 has an opening part 3321, which can compensate for the geometric error between the inner diameter of the compression cylinder 31 and the retaining structure 33 (the error is caused by the production tolerance and the thermal expansion of the material), and can also make the piston rod 32 move radially to solve the problem of misalignment of the axis F1 and the axis F2.

[0054] In this embodiment, the inner diameter of the open seal ring 332 and the inner diameter of the seal ring 331 are the same, and both are larger than the outer diameter of the piston rod 32, so that the open seal ring 332 and the seal ring 331 can both move radially relative to the piston rod 32 and both can rotate circumferentially around the piston rod 32, to further solve the problem of misalignment between the axis F1 and the axis F2.

[0055] When the piston rod 32 and the retaining structure 33 move relative to the axis F2 of the compression cylinder 31, the retaining structure 33 compensates for the error a between the axis F1 and the axis F2 and sets the open seal ring 332 and the seal ring 331 to the axis F2 of the compression cylinder 31. When the improved structure of the hydraulic shock absorber is working, the retaining structure 33 can rotate on the piston rod 32.

[0056] As shown in Figure 5 When the gap C1 between the open seal ring 332 of the retaining structure 33 and the compression cylinder 31 is oriented to be set at a position where the retaining structure 33 is closer to the cylinder wall of the compression cylinder 31, the area of the oil flow in the gap C1 through the opening part 3321 of the open seal ring 332 is reduced; when the oil flow area is smaller, the oil quantity restriction is greater, and the hydraulic braking system will generate a greater damping force.

[0057] As shown in Figure 6 When the gap C1 between the open seal ring 332 of the retaining structure 33 and the compression cylinder 31 is oriented to be set at a position where the retaining structure 33 is away from the cylinder wall of the compression cylinder 31, the area of the oil flow in the gap C1 through the opening part 3321 of the open seal ring 332 is increased; when the oil flow area is larger, the oil quantity restriction is smaller, and the hydraulic braking system will generate a smaller damping force.

[0058] As can be seen, exposing and covering the gap C1 will cause a significant change in the oil flow area, which will make the damping force of the hydraulic shock absorbing system have a higher variability. In order to solve this problem, the inventors have further improved the structure of the open seal ring 332.

[0059] According to one embodiment of the present application, as shown in Figure 7 and Figure 8 The open seal ring 332 is formed with a notch 3322, and the notch 3322 is oppositely arranged with the opening part 3321 of the open seal ring 332 along the diameter direction of the open seal ring 332. Specifically, the notch 3322 is a groove formed on the outer wall of the open seal ring 332, and the opening direction of the notch 3322 is oppositely arranged with the opening part 3321 along the diameter direction of the open seal ring 332.

[0060] In this embodiment, as shown in Figure 9 and Figure 10As shown, when the sealing ring 331 of the retaining structure 33 moves radially relative to the piston rod 32, whether to the position where the opening part 3321 of the opening sealing ring 332 is located or to the position where the notch 3322 of the opening sealing ring 332 is located, the oil flow area in the gap C1 between the retaining structure 33 and the compression cylinder 31 can be kept in a relatively stable area, so that the amount of oil flowing through the gap C1 can be kept stable, thereby realizing the variable control of the damping force of the hydraulic damping system.

[0061] Further, in order to make the combination of the sealing ring 331 and the opening sealing ring 332 more stable and prevent them from separating during work to affect the function of the retaining structure 33, as shown, Figure 11 As shown, the sealing ring 331 is provided with an insertion ring 3311 in the direction towards the opening sealing ring 332, and the insertion ring 3311 can extend into the opening sealing ring 332.

[0062] Specifically, the outer diameter of the insertion ring 3311 is slightly smaller than the inner diameter of the opening sealing ring 332, so that after the insertion ring 3311 is inserted into the opening sealing ring 332 and the opening sealing ring 332 produces a compression movement, the geometric error in the compression cylinder 31 can be compensated, and the relative positional stability of the sealing ring 331 and the opening sealing ring 332 is also realized.

[0063] According to an embodiment of the utility model, as shown, Figure 12 As shown, the end faces of the sealing ring 331 and the opening sealing ring 332 are provided with centering structures 5 that can cooperate with each other.

[0064] Specifically, the centering structures 5 include a first inclined surface 3312 formed on the end face of the sealing ring 331 and a second inclined surface 3323 formed on the end face of the opening sealing ring 332, the first inclined surface 3312 is inclined and arranged radially outward in the direction away from the opening sealing ring 332, and the second inclined surface 3323 is inclined and arranged radially outward in the direction close to the sealing ring 331.

[0065] Through the arrangement of the first inclined surface 3312 and the second inclined surface 3323, the sealing ring 331 and the opening sealing ring 332 can be better combined together, and the movement of the two relative to the piston rod 32 can be synchronized, further ensuring that the oil flow area in the gap C1 is unchanged, and ensuring the stability of the oil flow.

[0066] According to an embodiment of the utility model, as shown, Figure 13 As shown, the retaining structure 33 is a spring sealing ring, the end of the piston rod 32 is provided with a protruding column 321, and the spring sealing ring is sleeved on the protruding column 321.

[0067] By setting the retaining structure 33 as a spring seal ring, the spring seal ring is designed in a spiral structure, which can allow the spring seal ring to expand and compress during the operation of the improved structure of the hydraulic shock absorber. When the spring seal ring moves into the compression cylinder 31, the inner wall of the compression cylinder 31 can exert pressure on the outer diameter of the spring seal ring, under the action of the pressure, the spring seal ring starts to twist (similar to a coil spring) and adjusts its outer diameter to adapt to the inner diameter of the compression cylinder 31, so that the piston rod 32 moves radially to ensure that the axis F1 of the piston rod 32 is coaxially arranged with the axis F2 of the compression cylinder 31.

[0068] According to one embodiment of the utility model, as Figure 14 shown, the retaining structure 33 is a sealing ring formed by sequentially splicing a plurality of arc-shaped pieces 333, and every two adjacent arc-shaped pieces 333 are connected by an elastic piece 334, and the end of the piston rod 32 is formed with a convex column 321, and the sealing ring is sleeved on the convex column 321.

[0069] Specifically, in the embodiment, the arc-shaped piece 333 is four, and the four arc-shaped pieces 333 are spliced end to end to form a ring-shaped structure, and the arc-shaped elastic piece 334 is connected between the inner sides of the two adjacent arc-shaped pieces 333, when the retaining structure 33 is sleeved on the convex column 321, the elastic piece 334 is located between the retaining structure 33 and the convex column 321, and the elastic pieces 334 can provide radial elastic force for the retaining structure 33 between the compression cylinder 31 and the convex column 321, in addition, the retaining structure 33 composed of the arc-shaped pieces 333 can move radially on the convex column 321 to compensate for the misalignment of the axis F1 of the piston rod 32 and the axis F2 of the compression cylinder 31. When the retaining structure 33 moves radially relative to the piston rod 32, it moves to the position of the opening part 3321 of the open seal ring 332 or the position of the notch 3322 radially opposite to the opening part 3321, the oil flow area can be maintained on a relatively stable area, thereby maintaining the stability of the oil flow through the gap C1, and the purpose of controlling the damping force of the hydraulic shock absorbing system is achieved.

[0070] Embodiment two

[0071] As Figures 1 to 14 shown, the utility model also provides a hydraulic shock absorber, which comprises an outer cylinder 1 and a piston 2 movably arranged in the outer cylinder 1, and the hydraulic shock absorber further comprises an improved structure 3 of the hydraulic shock absorber as described above, and the improved structure 3 is located in the hydraulic shock absorber. Wherein, the specific structure and beneficial effects of the improved structure 3 of the hydraulic shock absorber are the same as those of the first embodiment, and will not be repeated here.

[0072] The hydraulic shock absorber of the utility model has the improved structure 3 added at the end of the piston compression stroke in the outer cylinder 1, so that the progressive characteristic of the increased damping force is adjusted and obtained, and the vehicle parts are prevented from being damaged by the excessive force generated by the hydraulic shock absorbing system.

[0073] The above-described specific embodiments further specifically describe the purpose, technical scheme and beneficial effects of the utility model, and it should be understood that the above-described specific embodiments are merely specific embodiments of the utility model and are not used to limit the protection scope of the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An improved structure of a hydraulic shock absorber, characterized in that, include: A compression cylinder is located inside the hydraulic shock absorber; A piston rod is connected to the piston of the hydraulic shock absorber, and the piston rod can be in a sealing sliding fit with the compression cylinder; A retaining structure is sleeved on the end of the piston rod, and the retaining structure is rotatably sealed between the inner wall of the compression cylinder and the piston rod.

2. The improved structure of the hydraulic shock absorber as described in claim 1, characterized in that, The retaining structure includes a sealing ring and an open sealing ring stacked together. The end of the piston rod is formed with a protrusion. Both the sealing ring and the open sealing ring are sleeved on the protrusion and are constrained on the protrusion by a retainer.

3. The improved structure of the hydraulic shock absorber as described in claim 2, characterized in that, A groove is formed on the open sealing ring, and the groove is positioned opposite to the opening of the open sealing ring along the diameter direction of the open sealing ring.

4. The improved structure of the hydraulic shock absorber as described in claim 2 or 3, characterized in that, The inner diameter of the sealing ring is the same as the inner diameter of the open sealing ring, and both are larger than the outer diameter of the protrusion.

5. The improved structure of the hydraulic shock absorber as described in claim 2, characterized in that, The end faces of the sealing ring and the open sealing ring that are attached to each other form a centering structure that can cooperate with each other.

6. The improved structure of the hydraulic shock absorber as described in claim 5, characterized in that, The centering structure includes a first inclined surface formed on the end face of the sealing ring and a second inclined surface formed on the end face of the open sealing ring. The first inclined surface is radially inclined outward in a direction away from the open sealing ring, and the second inclined surface is radially inclined outward in a direction away from the sealing ring.

7. The improved structure of the hydraulic shock absorber as described in claim 6, characterized in that, The inclination angle of the first inclined plane is the same as that of the second inclined plane.

8. The improved structure of the hydraulic shock absorber as described in claim 3, characterized in that, The sealing ring has an insertion ring protruding in the direction of the open sealing ring, and the insertion ring can extend into the open sealing ring.

9. The improved structure of the hydraulic shock absorber as described in claim 1, characterized in that, The retaining structure is a spring sealing ring, and a protrusion is formed at the end of the piston rod, with the spring sealing ring sleeved on the protrusion.

10. The improved structure of the hydraulic shock absorber as described in claim 1, characterized in that, The retaining structure is a sealing ring formed by sequentially splicing multiple arc-shaped parts together. The arc-shaped parts are connected by elastic elements. The end of the piston rod has a protrusion, and the sealing ring is sleeved on the protrusion.

11. The improved structure of the hydraulic shock absorber as described in claim 10, characterized in that, The elastic element is located between the sealing ring and the protrusion.

12. The improved structure of the hydraulic shock absorber as described in claim 1, characterized in that, The inner wall of the compression cylinder is provided with a damping groove extending along its axial direction, the damping groove extending from the opening of the compression cylinder to the bottom of the compression cylinder.

13. The improved structure of the hydraulic shock absorber as described in claim 12, characterized in that, There are multiple damping grooves, which are spaced apart along the circumferential direction of the compression cylinder.

14. A hydraulic shock absorber, characterized in that, The hydraulic damper includes an outer cylinder and a piston movably disposed within the outer cylinder, and further includes an improved structure of the hydraulic damper as claimed in any one of claims 1 to 13, the improved structure being located within the hydraulic damper.

Images