Shock absorber with second outer cylinder

Abstract

The invention relates to a damper comprising a first outer cylinder and a second outer cylinder connected to the first outer cylinder, wherein the two outer cylinders are mechanically fixed to each other in such a way that they are held by a hoop element, wherein the hoop element is configured as a double hoop which clamps the two cylinders over a circumferential area of more than 180°, respectively.

Description

Technical Field

[0001] The present invention relates to a vibration damper having a first external cylinder and a second external cylinder, as described in the preamble of claim 1. Background Technology

[0002] Especially for dampers optimized for shorter axial structural lengths, a second outer cylinder is typically included, which may house a damping medium reservoir or, if necessary, an adjustable damping valve. This requires fluid communication between the first and second outer cylinders. This fluid communication is typically formed by a rigid sleeve. For example, see reference DE 103 55 151 A1. In DE 103 55 151 A1, the sleeve serves only as a passageway. The mechanical fixing of the additional housing to the outer cylinder is provided by a web extending parallel to the sleeve. A primary reason for the parallel arrangement of the webs is that the side passages at the contact points between the sleeve and the outer cylinder or additional housing are too narrow for welding tools. This drawback is particularly pronounced with larger outer cylinder diameters, and can only be compensated for by correspondingly longer sleeves. However, this solution leads to spatial arrangement disadvantages.

[0003] If we consider, for example, document DE 102 60 395 B3, the impact of sleeve length on manufacturing feasibility becomes clearer. In this configuration, instead of welding, the additional housing is connected to the outer cylinder by multiple hoops (not shown). Such hoops are known from document DE 10 2011 075 910 A1, but they have drawbacks, such as the requirement to ensure that the preload within the hoops remains effective throughout the damper's service life. Otherwise, leakage may occur, potentially leading to complete damper failure. Summary of the Invention

[0004] The purpose of this invention is to provide a fixing technique between two cylinders that is easy to assemble and has high durability.

[0005] This objective is achieved by constructing the clamp element as a double clamp, wherein the double clamp clamps respectively enclose the two cylinders in a circumferential region greater than 180°.

[0006] The advantage of this structural form is that the double clamp can be designed as a robust component, and fatigue strength issues are not expected.

[0007] In an advantageous embodiment, the double clamp has two double half-shells with the same radius of curvature. The double half-shells can be easily radially fitted onto the two cylinder blocks.

[0008] Preferably, the dividing seam between the two twin shells is substantially parallel to the orientation of the pressure-conducting conduit between the two cylinders. The pressure medium filling the two cylinders generates expansion force. Through this arrangement of the dividing seam, the two twin shells withstand shear loads. This type of load is mechanically easier to handle than loads in the direction of fastener loosening between the twin shells.

[0009] Optionally, the two twin shells are provided with at least two centering elements, which bear lateral forces parallel to the dividing seam. The centering elements reduce the locking force required between the twin shells. The centering elements may be integrally formed with the twin shells or constitute separate components, such as mating parts.

[0010] Preferably, the two double-shell halves are held together by clamping elements.

[0011] Considering simple installation and optimal space utilization, the clamping element and centering element constitute a functional unit.

[0012] Another measure to enhance the function of the double clamp is that the double clamp is at least partially provided with an elastomeric element on its inner side. The elastomeric element protects the preferably machined surfaces of the two cylinders from scratches.

[0013] In another advantageous design, the at least one elastomeric element has a preload force whose line of action coincides substantially with the longitudinal axis of the connecting sleeve. An axial preload force is generated between the connecting sleeve and at least one cylinder by closing the double clamp.

[0014] To facilitate the installation of the two double-shell structures, the two double-shell structures are connected to each other at the dividing seam via a pivot joint.

[0015] The twin half-shell is preferably made of plastic to avoid potential contact corrosion with the two cylinders. Attached Figure Description

[0016] The invention will be described in more detail below with reference to the accompanying drawings.

[0017] The diagram is as follows: Figure 1 This is a full sectional view of the vibration damper; Figure 2 and 3 yes Figure 1 The external view of the shock absorber is shown. Figure 4 It shows Figure 1 The hydraulic connection between the cylinders is shown. Figure 5 and 6 It shows Figure 1 The double clamp shown; Figure 7 and 8 A double clamp with a riveted connection is shown; Figure 9 and 10 A double clamp employing a pivot joint is shown; Figures 11 to 15 It shows Figure 9 and 10 Alternatives to the design shown. Detailed Implementation

[0018] Figure 1 The diagram shows a full sectional view of the shock absorber 1. In this embodiment, the shock absorber 1 includes a working cylinder 3 completely filled with damping medium, within which a piston rod 5, together with a piston 7, is axially movable. The piston 7 can optionally be equipped with a damping valve or an overpressure valve, dividing the working cylinder 3 into a working chamber 9 on the piston rod side and a working chamber 11 away from the piston rod. The working chamber 9 on the piston rod side is connected to a fluid passage 15 via at least one connector opening 13, extending to a first adjustable damping valve device 17, which generates a damping force when the piston rod 5 extends out of the working cylinder 3 (see...). Figure 2 and 3 The structural design of the adjustable damping valve device 17 is secondary to the present invention. For example, see reference DE 10 2015 200 348 A1. Figure 1 In general, the internal structure of the shock absorber is not important to this invention.

[0019] The working chamber 11, located away from the piston rod, is also connected to the second adjustable damping valve device 23 via the connector opening 19 and the second fluid passage 21. This second adjustable damping valve device generates damping force during the retraction of the piston rod 5. Figure 1 As shown in the diagram, the structure of the second adjustable damping valve device 23 is the same as that of the first damping valve device 17. The two fluid channels 15 and 21 are not only spatially separated by an annular dividing element 25, but also hydraulically separated. On the outflow side, the two damping valve devices 17 and 23 are connected to a common annular storage channel 31 within the dividing element 25 via an outflow channel 27.

[0020] The working cylinder 3 is completely enclosed by the outer cylinder body 33, and thus extends from the piston rod guide 35, which serves as the seal for the working chamber 9 on the piston rod side, to the bottom 37 of the working chamber 11 away from the piston rod. The annular space between the outer cylinder body 33 and the working cylinder 3 is available for use by two fluid passages 15, 21.

[0021] The outer cylinder body 33 comprises three sections 33A, 33B, and 33V, which are non-detachably connected together. The middle section of the outer cylinder body 33 is formed by a valve seat 33V. The sleeve-shaped valve seat 33V is welded to the first cylinder body section 33A, which extends to the piston rod guide 35. The second cylinder body section 33B defines the second fluid passage 21 from the bottom 37 to the valve seat 33V.

[0022] In this embodiment, the valve seat 33V has a large wall thickness to facilitate a very simple connection between the valve housing 39 of the adjustable damping valve devices 17, 23 and the external cylinder 33. This structural form is not mandatory for this invention.

[0023] Figure 1 and Figure 2 As shown, a second cylinder 41 is fixed to the outer cylinder 33 of the damper 1. A rigid connecting sleeve 43 forms a fluid connection 45 for exchanging the damping medium between the joint opening 47 of the first outer cylinder 33 housing the connecting sleeve 43 and the joint opening 49 of the second cylinder 41. In this example, the second cylinder 41 has a storage section containing a damping medium storage section 51 and a gas filling section 53. An axially movable separating piston 55 is provided between the two working media. However, the additional housing 41 can also be used to house a pump or damping valve device.

[0024] The connecting sleeve 43 is connected to the second outer cylinder 41 by means of material fit and hydraulic sealing. The slightly larger wall thickness of the valve seat 33V compared to the adjacent cylinder sections 33A and 33B provides for the sealing insertion of the connecting sleeve 43 into the stepped bore joint opening 47 of the outer cylinder 33 (see [link]). Figure 4 The feasibility of ( ).

[0025] like Figure 2 and Figure 3 As shown in the comparison, the second outer cylinder 41 is held radially on the first outer cylinder 33 by a double clamp 57 in terms of its angular direction around the longitudinal axis 59 of the connecting sleeve 43. For this purpose, the double clamp 57 clamps the two cylinders 33 and 41 in a circumferential area of ​​greater than 180°.

[0026] like Figure 5 and Figure 6 As shown, the double clamp 57 has two double half-shells 57A and 57B with the same radius of curvature. The dividing seam 61 between the two double half-shells 57A and 57B is substantially parallel to the orientation of the connecting sleeve 43 that transmits pressure between the two cylinders 33 and 41 (see...). Figure 1Preferably, the dividing seam 61 does not extend in a simple straight line, but tends to be slightly arrow-shaped. At the intermediate contact section 61K, the dividing seam extends along the transverse axis of the two cylinder blocks. On both sides of the contact section 61K, the dividing seam 61 is bent radially outward.

[0027] The two double-shell halves 57A and 57B are preferably made of plastic. The working pressure inside cylinders 3, 33, and 41 generates a radial separation force between the two cylinders 33 and 41. For the double-shell halves 57A and 57B, this separation force manifests as a lateral force, which is borne by equipping the two double-shell halves with at least two centering elements 57Z, which bear the lateral force parallel to the dividing seam 61.

[0028] To reliably keep the two double-shell halves 57A and 57B closed, they are held together by a clamping element 57S. The clamping element 57S consists of a snap-fit ​​that passes through a through-hole 57D in one of the double-shell halves 57A and 57B. A snap-fit ​​or similar locking element is preferred over a threaded connection because the connection between the two cylinders 33 and 41 should not be opened by untrained personnel due to the pressure medium filling inside the cylinders 33 and 41. For this purpose, the snap-fit ​​ends are designed to be tapered to increase the difficulty of using pliers.

[0029] exist Figure 5 As can be seen in the cross-sectional view, the clamping element 57S and the centering element 57Z constitute a functional unit. The centering element 57Z consists of a cylinder section that engages with a through hole 57D of another double half-shell, which is designed as a stepped bore. The latch of the clamping element 57S extends from the cylinder section through the stepped bore to the back of the double half-shell.

[0030] Figure 5 and Figure 6 As shown, the double clamp 57 may optionally have an elastomeric element 57E at least partially disposed on its inner side. In a further design, the at least one elastomeric element 57E may have a preload, the line of action of which coincides substantially with the longitudinal axis 59 of the connecting sleeve 43. In this way, any manufacturing tolerances in the connection components from the first outer cylinder to the connecting sleeve and then to the second outer cylinder can be compensated for. Figure 5 In the diagram, the elastomer element 57E with this function is shown as an additional element.

[0031] Figure 7 and Figure 8A double clamp 57 is shown, in which the double half-shells 57A and 57B are held together by a riveted connection 57N. Here, the clamping and centering elements 57S and 57Z are also integrated into a common component, namely the rivet 57n or the riveted connection 57N. This technical solution simplifies the manufacture of the double half-shells 57A and 57B from plastic, as the clamping and centering elements 57S and 57Z are no longer integrally manufactured with one of the double half-shells 57A and 57B using injection molding technology. Furthermore, the riveted connection 57N between the two double half-shells 57A and 57B is more difficult to open because the two rivet heads are recessed into the through-holes 57D of the double half-shells 57A and 57B. To open the double half-shells 57A and 57B, they must be sawed open or the riveted connection 57N must be drilled, these steps constituting a certain safety hurdle.

[0032] Figure 9 and Figure 10 One embodiment of the double clamp 57 is shown, wherein two double half-shells 57A, 57B are connected to each other along the dividing seam 61 by a pivot joint 57G. Preferably, the pivot joint 57G is located at the turning point of the two double half-shells 57A, 57B, i.e., spatially in the middle of the two double half-shells 57A, 57B. Closing movement on one half-shell will also cause closing movement on the other half-shell. Combined clamping and centering elements are also used here, wherein the pivot joint 57G guides the two double half-shells 57A, 57B to move closer to each other even when the clamping element 57S is open. In the region of the centering element 57Z with the clamping element 57S, the two double half-shells 57A, 57B overlap in the circumferential direction. The pivot joint 57G bears part of the load applied to the double clamp 57 by the internal working pressure of the damper. However, the overlap also contributes to the stability of the closed double clamp 57.

[0033] Figure 11 A double clamp 57 employing a pivot joint 57G is shown, which is based on Figure 9 and 10 The design of the variant shown. The main difference lies in the design of the centering and clamping functions. Figure 9 and 10 In the double clamp 57, the clamping element 57S or snap fastener not only performs the clamping function but also the centering function. The snap fastener engages with a groove extending in the circumferential direction, which serves as the centering element 57Z. The dividing seam 61 between the two double half-shells 57A and 57B is designed as a butt joint (stumpfer Stoß).

[0034] exist Figure 12 middle, Figure 11The double half-shell 57A is shown as a single part, and it can be seen that the clamping element 57S is positioned circumferentially ahead of the centering element 57Z. Both ends of the double half-shell 57A have an external recess 57TA and an internal recess 57TI, which open on one side towards the end face 57ST of the double half-shell 57A. Referring to the same circumferential area, the recess 57TA is formed in the outer wall 57AW, while another recess 57TI is formed in the inner wall 57IW. Therefore, when viewed directly at the end face 57ST, the recesses 57TA and 57TI are arranged in an alternating pattern at the dividing seam 61. The recess 57TA in the outer wall has a constant radial width, and combined with a gradually increasing axial height along the circumferential direction, a raised side 57SF exists starting from the clamping element 57S. The recess 57TI in the inner wall 57IW also has a raised side 57SF starting from the clamping element 57S.

[0035] Figure 13 A second double-shell 57B is shown, which also has recesses 57TA2 at both ends in the outer wall 57AW, on which a locking profile 57R for clamping element 57S is formed at the circumferentially closed end. The recesses 57TA2 in the outer wall 57AW are provided with guide ramps 57ER that slope toward the closed end of the recesses 57TA2. The recesses 57TI2 in the inner wall 57IW may also be provided with guide ramps 57ER, which also slope toward the closed end of the recesses 57TI2.

[0036] The pivot joint 57G is formed by a joint pin 57GB on the double half-shell 57B, which has an axially defined profiled protrusion 57PN. Correspondingly, the support opening 57Ö in the double half-shell 57A has an axial groove 57X. Figure 14 and 15 The installation process is illustrated. For clarity, outer cylinder block 33 and outer cylinder block 41 are not shown. The two double-shell halves 57A, 57B are visually aligned with each other, with the support opening 57Ö overlapping the articulated pin 57GB. The form-fit connection between the axial groove 57X ​​and the contoured protrusion 57PN causes the two double-shell halves 57A, 57B to be aligned with each other in the circumferential direction, thus defining the... Figure 15 The installation position is shown. In the outer walls of the two double-shell halves 57A and 57B, the profile of the guide ramp 57ER of the recess 57TA2 overlaps with the side surface 57SF of the recess 57TA. When the two double-shell halves 57A and 57B move axially relative to each other, they also undergo rotational relative motion, wherein the clamping element 57S penetrates deeper into the recess 57TA2 in the outer wall of the other double-shell halves 57B and crosses the locking profile 57R until it reaches... Figure 11The closed position is shown. The recesses 57TA, 57TI, 57TA2, and 57TI2 that are joined circumferentially at the ends of the double half-shells 57A and 57B not only fix the double half-shells 57A and 57B in the circumferential direction, but also prevent the simple axial lifting movement of one double half-shell 57A relative to the other double half-shell 57B, because one end of one double half-shell 57A and 57B is axially joined from above to the corresponding recess in the region of the dividing seam 61, while the opposite end of the dividing seam 61 is joined from below to the corresponding recess.

[0037] Furthermore, there is an overlap along the circumferential direction in the areas of the recesses 57TA, 57TI, 57TA2, and 57TI2, so the pressure inside the damper 1 can be particularly well borne by the overlapping portion. List of reference numerals in the attached diagram: 1. Vibration damper 3 working cylinders 5. Piston rod 7 Pistons 9. Working chamber on the piston rod side 11. Working chamber away from the piston rod 13 Connector opening 15 Fluid Channels 17 First Adjustable Damping Valve Device 19 Connector opening 21 Second Fluid Channel 23 Second Adjustable Damping Valve Device 25. Separating elements 27 Outflow Channel 31 Storage Channels 33 External cylinder block 35 Piston rod guide 37 Bottom (Outer Cylinder Block) 39 valve housing 41 Second external cylinder block 43 Connecting sleeve 45 Flow connection part 47 Connector opening 49 Connector opening 51 Damping medium storage section 53 Gas filling section 55 Separator Piston 57 Double-link clamp 57A Double Half-Shell 57AB1 clamp 57AB2 clamp 57AW outer wall 57B Double Half-Shell 57D through hole 57E Elastomer Element 57ER Import Sloping Surface 57G pivot joint 57GB joint pin 57IW Inner Wall 57N Riveted Connection 57n Rivets for riveted joints 57PN contour protrusion 57R Lock Outline 57S clamping element 57ST end face 57TA Recess, outer wall 57TA2 Recess, outer wall 57TI recessed area, inner wall 57TI2 Recess, inner wall 57X Axial Groove 57Z centering element 57Ö Support opening 59. Longitudinal axis of the connecting sleeve 61 dividing seam 61K contact section 63. Horizontal axis 65. Lateral axis.

Claims

1. A shock absorber (1), the shock absorber comprising a first outer cylinder (33) and a second outer cylinder (41) connected to the first outer cylinder, wherein, The two cylinders (33, 41) are mechanically fixed to each other in such a way that the two cylinders (33, 41) are held by a hoop element (57), characterized in that the hoop element is constructed as a double clamp (57), the double clamp clamping the two cylinders (33, 41) in a circumferential area of ​​greater than 180° respectively.

2. The vibration damper (1) according to claim 1, characterized in that, The double clamp (57) has two double half shells (57A, 57B) with the same radius of curvature.

3. The vibration damper (1) according to claim 2, characterized in that, The dividing seam (61) between the two double half-shells (57A, 57B) is substantially parallel to the orientation of the connecting pipes that transmit pressure between the two outer cylinders (33, 41).

4. The vibration damper (1) according to claim 3, characterized in that, The two double-shell structures (57A, 57B) are equipped with at least two centering elements (57Z), which bear lateral forces parallel to the dividing seam (61).

5. The vibration damper (1) according to any one of claims 2 to 4, characterized in that, The two double half-shells (57A, 57B) are held together by a clamping element (57S).

6. The vibration damper (1) according to claim 5, characterized in that, The clamping element (57S) and the centering element (57Z) constitute a functional unit.

7. The vibration damper (1) according to any one of claims 1 to 6, characterized in that, The double clamp (57) is provided with an elastomeric element (57E) at least partially on its inner side.

8. The vibration damper (1) according to claim 7, characterized in that, At least one of the elastomer elements (57E) has a preload force whose line of action is substantially coincident with the longitudinal axis (59) of the connecting sleeve (47).

9. The vibration damper (1) according to claim 3, characterized in that, The two double-shell halves (57A, 57B) are connected to each other at the dividing seam (61) by a pivot joint (57G).

10. The vibration damper (1) according to any one of claims 2 to 9, characterized in that, The double half-shells (57A, 57B) are made of plastic.

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