Restriction body of a vibration damper

Abstract

The present invention discloses a limiting body for a vibration damper and a damping valve device for a vibration damper, comprising a valve body of variable diameter guided by a valve support and, starting from a flow-through position, the valve body takes a limiting position by a radial closing movement toward the flow-guided surface, depending on the flow velocity of the damping medium within the limiting body, wherein the closing movement of the valve body is controlled by at least one damping device.

Description

Technical Field

[0001] This invention relates to a limiting element of a vibration damper. Background Technology

[0002] DE 10 2016 210 790A1 discloses a damping valve device having a valve body with a variable diameter that performs a radial closing motion according to the flow velocity within the restrictor, thereby changing the cross-section of the restrictor.

[0003] The valve body has transverse grooves and is radially elastic. The limiting ring determines the maximum expansion of the valve body and also ensures the valve body's return movement towards its initial position, where the flow passage cross-section of the limiting body is also at its maximum.

[0004] In such damping valve devices, the response behavior of the valve body to changes in flow rate decisively determines the quality of the damping valve device. Response speed and the dimensions of the minimum limiting body cross-section play a crucial role in this regard. Summary of the Invention

[0005] The objective of this invention is to further develop the type of damping valve device discussed in terms of functional quality.

[0006] This objective is achieved by the fact that the closing movement of the valve body is controlled by at least one damping device.

[0007] Damping devices can have a significant impact on the response speed of damping valve devices. The maximum achievable damping force can be considered independent of this. In addition to response speed, the engagement point of the damping valve device also changes.

[0008] In a further advantageous embodiment, the damping device is supported on the valve support. The aim is to avoid any additional frictional effects between the damping valve assembly and the cylinder. Furthermore, the damping device will then depend on the dimensional tolerances of the cylinder.

[0009] One possibility for adapting the damping device, and therefore the operating behavior of the damping valve device, is that the damping device only begins to function after the valve body has completed its free travel. From the position of maximum flow in the valve body, the damping force of the limiting body increases only moderately. This initial effective range of the limiting body can be traversed fairly quickly, allowing high damping force to accumulate at a corresponding speed. This setup is suitable for designing more dynamic vibration dampers.

[0010] To make the orientation of the restraint body more conducive to comfort, the damping device can start operating from the initial position of the valve body. The distinction here is whether the damping device generates basic damping force from the initial position or only accumulates damping force after the expansion motion begins.

[0011] In principle, the valve body can control multiple damping devices, which are placed around the valve body, for example, in a circumferential direction, and these damping devices operate at different diameters of the valve body. The damping devices thus operate in a cascade manner, allowing for highly selective adaptation of the required damping force characteristics of the damping devices.

[0012] The damping device has a particularly simple design and is formed by at least one elastomer body.

[0013] Alternatively, the damping device can be implemented as a hydraulic damping device.

[0014] By implementing the elastomer body as a hollow body that can be filled with a damping medium, a combination of the two construction principles can be achieved. This design is also very easy to manufacture and assemble.

[0015] Fundamentally, damping valve assemblies do not absolutely require a damping device to be installed on the valve body. To utilize the standard design of the valve support, the damping device is supported on a cover of the valve support. Furthermore, the additional cover simplifies the assembly of the damping valve assembly and creates extra installation space for the damping device.

[0016] In the case of a hydraulic damping device, if the valve body and valve support form a pressure chamber that is compressed during the expansion movement of the valve body, a particularly simple design can be achieved because the components used for the pressure chamber are present under any circumstances.

[0017] The minimalist design is characterized by a pressure chamber defined by the top side of the valve body and a portion of the sidewall of an annular groove. The completed pressure chamber can then be made usable simply by inserting a seal or forming raised annular walls on both sides.

[0018] Alternatively, the valve support can have a hydraulic damping device with at least one pressure chamber filled with a damping medium, in which a displacement body controlled by the valve body performs a working movement. This design provides a number of parameters to suit the damping characteristics of the damping device.

[0019] In another embodiment, the pressure chamber is formed by the valve body. This variant offers the advantage of ease of assembly because the components of the damping device are first mounted on the valve body and then inserted into the annular groove of the valve support.

[0020] For this purpose, the shifting element can also be designed as a connecting rod mounted on the valve support. Through the valve body's return motion, the shifting element always moves to its initial position. The shifting element does not require a separate return spring. Attached Figure Description

[0021] The invention will be explained in more detail with reference to the following accompanying drawings.

[0022] In the attached diagram:

[0023] Figure 1 A cross-sectional view of the vibration damper within the area of ​​the damping valve device is shown;

[0024] Figure 2 It shows Figure 1 The diagram shows a plan view of the valve body of the limiting body.

[0025] Figure 3 and Figure 4 A damping device with an elastomer body is shown;

[0026] Figure 5 The damping device on the cover of the valve support of the limiting body is shown;

[0027] Figures 6 to 10 A hydraulic damping device for the limiting body is shown;

[0028] Figure 11 It shows Figures 3 to 10 The damping force characteristics of the embodiment shown. Detailed Implementation

[0029] Figure 1 A damping valve device 1 for a vibration damper 3 of arbitrary structure is shown, with only a portion illustrated. The damping valve device 1 includes a first damping valve 5 having a damping valve body implemented as a piston 7, which is fastened to a piston rod 9.

[0030] The damping valve body 7 divides the cylinder 11 of the vibration damper into a working chamber on the piston rod side and a working chamber away from the piston rod side, both of which are filled with damping medium. Through channels for their respective flow directions are formed on different pitch circles of the damping valve body 7. The configuration of the through channels should be considered purely illustrative. The outlet sides of the through channels 17 and 19 are at least partially covered by at least one valve disc 21 and 23.

[0031] In addition, the vibration damper has a tension stop 25 that abuts against a stop surface of the cylinder, such as the piston rod guide 27, due to the limited upward extension movement of the piston rod 9.

[0032] The tension stop 25 includes a tension stop disc that serves as a valve support 29, which is directly fixed to the piston rod by a forced coupling. For example, an annular elastomer element 31 is placed on the upper side of the valve support 29, which can be held in place by a small radial prestress even when the piston rod 9 vibrates. From the point of contact with the stop surface, the elastomer element 31 acts as an additional support spring.

[0033] The support member 29 has a surrounding groove 33 in which a variable-diameter valve body 35 is guided. The diameter of this valve body 35 can be increased, forming a component of a limiting body 37 as part of the damping valve device 1. The valve body 35 forms the limiting body 37 with the inner wall 39 of the cylinder 11, where the inner wall 39 forms a flow guiding surface. In principle, the invention can also be formed in a support disc independent of the tension stop.

[0034] Externally, the valve body 35 has a return spring 41, for example, in the form of a retaining ring. This return spring 41 may also optionally perform the function of an expansion limiter for the valve body 35.

[0035] When the piston rod speed is within the first operating range, for example, less than 1 m / s, the limiting body 37 is fully open. The damping force is then generated entirely by the through channels 17 and 19 and the valve discs 21 and 23. When there is flow toward the valve discs 21 and 23, the valve discs 21 and 23 rise from the valve seat surfaces 47 and 49. The upward movement is limited by the support discs 51 and 53 in their respective cases.

[0036] When the piston rod speed exceeds the limit speed of the first operating range, i.e., exceeds the second operating range of 1 m / s as exemplified, the valve body 35 moves to the restricted position and, in the process, performs a closing movement toward the guide surface 39. Due to the high flow velocity of the damping medium within the annular gap-shaped restrictor 37, pressure is reduced, causing the valve body 35 to expand radially. However, to ensure that the restrictor 37 is not potentially blocked, a defined minimum flow cross-section is maintained by the return spring 41, or the outer contour of the valve body, together with the guide surface 39, defines the minimum flow cross-section.

[0037] Figure 2 Showing from Figure 1 The diagram shows a plan view of the optional valve body 35, representing the cross-section of the vibration damper 3. For clarity, the valve support 29, the retaining ring 41, and the piston rod 9 are omitted from the figure. It can be seen that the valve body 35 has a lateral clearance 55, which reduces the pressure required for the radial expansion movement of the valve body 35. The valve body 35 is shown in the flow-through position at minimum flow velocity. Therefore, the flow-through cross-section 57 is the largest. The flow-through cross-section 57 is defined by the inner wall 39 of the cylinder 11 and the outer surface 45 of the valve body 35.

[0038] The valve body 35 has a profile 59 that restricts an annular cross-section between the valve body 35 and the inner wall 39 of the cylinder 11. In this illustration, the restricting profile 59 is implemented as a single radial protrusion on the side surface 45. This creates a C-shaped restricting section 57. Between the cam-shaped protrusion 59 and the inner wall 39, there is a significantly reduced width restricting section 61, which is maintained even under maximum expansion movement of the valve body 35. Here, the dimensions of the radial protrusion 59, or restricting portion, are determined such that it exists only on the restricting body 37 ( Figure 1 The operating range of the radial profile 59 affects the damping effect. Due to the relatively large circumferential range of the radial profile 59, a clearance relative to the side surface 45 of the valve body 35 can be added outside the radial profile 59.

[0039] also, Figure 2 The valve body 35 is shown to include at least two branches 63, 65, which are mounted movably around a pivot support 67. This feature is independent of the radial protrusion 59, but the two features complement each other in an advantageous manner given that the limiting profile 59 forms part of the pivot support 67 (e.g., support pin 69).

[0040] In this embodiment, branches 63 and 65 overlap in the circumferential direction, and a pivot support 67 is formed in the overlapping area. There is also overlap between the two branches 63 and 65 in the region of the lateral gap 55 to minimize the destructive leakage cross-section. Figure 1 As shown, the valve support 29 has two receiving openings 73 that receive the support pin 69. The receiving openings on the valve support 29 can be implemented as simple through holes, for example. The same applies to the support openings 75, 77. However, to provide some clearance within the pivot support, one of the support openings 75, 77 can also be implemented as a slot along the circumferential direction of the branch.

[0041] When the restrictor is activated, i.e., when the flow velocity in the restrictor section 57 is correspondingly high, the two branches 63 and 65 of the valve body pivot radially about the pivot support 67 toward the inner wall of the cylinder 11. If branches 63 and 65 are in full surface contact, the restrictor section 61 remains open and the damping effect is established.

[0042] Figure 3 The cross-section of the valve support 29 is shown in the region confined within the restrictor 37. In this enlarged view, it can be seen that the restrictor 37 has a damping device 79 that acts opposite to the closing movement of the valve body 35 and thus controls the overall behavior of the restrictor 37.

[0043] In this exemplary embodiment, a damping device 79, formed by at least one elastomer body 81, is supported on a valve support 29. For this purpose, the valve support 29 has a surrounding or alternatively segmented web 83 into which at least one elastomer body 79 is fitted. A radial clearance exists between the valve body 35 and the elastomer body 81, thereby ensuring that the expansion rate of the valve body 35 within a first actuation stroke range, and therefore the response rate, is controlled by the pressure or pressure forces within the pressure chamber 85 and the restraint body 37, and by the force of the return spring 41. The pressure chamber 85 is defined by the inner surface 87 of the valve body 35, the bottom surface 89 of the recess, and the recess sidewalls 91, 93 of the valve support 29. The damping medium flows into the pressure chamber 85 via the inlet opening 95 and flows back out via the outlet channel 97. The cross-sectional ratio of the inlet channel 95 to the outlet channel 97 affects the pressure accumulation in the pressure chamber 85. Once the valve body has completed its free travel 99 through its radial expansion motion and rests against the elastic body 81, the elastic body 81 applies an additional spring force on one hand, and a damping force on the other hand, opposite to the expansion motion of the valve body 35. Therefore, the expansion motion of the valve body toward the guide surface 39 on the cylinder 11 is slowed down.

[0044] For example, Figure 2 Two damping devices are depicted, each with different free travel relative to branches 63 and 65. Therefore, damping devices 79 function at different diameters of the valve body 35. The number and associated free travel 99 allow for the determination of additional parameters for the setting of the limiting body 37 and thus the entire damping valve assembly 1.

[0045] Figure 4 It shows the basis Figure 3 In one embodiment of the limiting body 37, the damping device 79 of the limiting body 37 is already in operation from the initial position where the diameter of the valve body 35 is at its smallest during expansion movement. In this case, it can be further specified that the elastic body 81 rests solely against the valve body 35, or that the elastic body already has a significant prestress that acts as a reaction force against the expansion movement.

[0046] and Figure 3 The illustrated embodiments form a comparison, Figure 5 The damping device 79 shown is supported on a cover 101 separate from the valve support 29. This cover 101 can be used as an option and offers the advantage that the valve support 29 does not require a web 83 to close the annular groove 33, thus simplifying its manufacture. Here, the cover 101 is centered on the shoulder of the top side of the valve support and, since no significant axial force is generated, can be easily secured by an interference fit.

[0047] exist Figure 3 and Figure 4 In the illustrated embodiment, the flexing work on the elastomer is used for damping. Figure 6 A variant is shown in which the damping device additionally has hydraulic damping. For this purpose, based on... Figure 3 The elastomeric body 81 of the illustrated structural principle is implemented as a hollow body, which can be filled with damping medium and at least partially emptied through opening 103. Opening 103 acts as a confinement through which the volume 105 of damping medium is removed from the hollow body by the expanding valve body 35. Hydraulic damping further provides an advantage for the speed-dependent effect of the damping device, i.e., when the valve body 35 expands relatively rapidly, the damping device 79 also generates a higher damping force that acts in the opposite direction. During the reset movement, the elastomeric body 81 relaxes again, and thus the hollow body is filled with damping medium through opening 103.

[0048] Figure 7 A limiting body 37 with a valve support 29 is shown, which also has a hydraulic damping device 79, wherein the valve body 35 and the valve support 29 form a pressure chamber 107 that is compressed during the expansion movement of the valve body. For this purpose, the pressure chamber 107 is defined by a top side 109 of the valve body and a portion of the recess sidewall of the annular recess 33. Separate annular webs 111 and 113, also formed by separate seals, are arranged on the top side 109 and the recess sidewall 93. The annular web 111 on the top side 109 extends inside the annular web 113 of the recess sidewall 93, with a radial gap between the two webs. This variant is a fully hydraulically driven damping device 79. The gap 115 between the annular webs 111 and 113 and the opposing wall region, or alternatively, a separate limiting opening 117 in the valve support 29, can be used to measure the limiting effect.

[0049] Figure 8 The limiting body 37 is depicted, wherein the valve support 29 has a hydraulic damping device having at least one pressure chamber 107 filled with a damping medium, and within this pressure chamber, a displacement body 119 controlled by the valve body 35 performs a working movement. Here, the pressure chamber 107 is formed corresponding to... Figure 2 In the web plate 83, or according to Figure 4 The cover 101 is located in the valve body. Compared to the conventional valve body 35, no changes are required to the valve body 35.

[0050] A pin-shaped component serves as a shifter 119, which enters the pressure chamber 107 and, in the process, moves out of the damping medium via the limiting opening 117. A return spring 121 ensures that the shifter 119 performs a reset motion back to its initial position. A free-stroke design can also be used here, in which the shifter is active even in the initial position of the valve body 35. The return spring 121 is sized such that it only ensures the reset motion of the shifter 119, but a higher elasticity can also be used to assist the return spring 41.

[0051] exist Figure 9 In the embodiment of the damping device 79 shown, this device is arranged within the valve body 35, i.e., the valve body 35 forms the pressure chamber 107. It is also here that the limiting opening 117 in the valve body 35 is used to generate damping force. It is also in this case that the cover 101 is used to simplify assembly. In principle, the valve support 29 can also be axially divided into upper and lower parts. In other respects, the operating principle is the same as... Figure 8 The illustrated embodiment is consistent.

[0052] Figure 10 A variant of the hydraulic damping device 79 is shown, wherein a displacement body 119 is implemented as a connecting rod that passes radially through the valve body 35 and is mounted on the valve support 29. In the illustration, the annular gap between the displacement body 119 and the wall forming the stepped opening of the pressure chamber serves as a limiting opening in which the displacement body is arranged. A seal 123 is responsible for sealingly separating the pressure chamber 107 of the damping device 79 relative to a pressure chamber 85 radially inside the valve body 35.

[0053] With its installation, the shifter 119 can have a certain angular mobility to avoid hindering the expansion movement of the valve body 35. Since the return spring 41 of the valve body 35 ensures the return of the shifter 119 by the movement of the valve body 35 relative to the valve support 29, the damping device 79 does not require a return spring.

[0054] Figure 11 The effect of damping device 79 on the damping force behavior of restrictor 37 is illustrated. Damping force characteristic "1" describes the damping force behavior of damping valve 5 without restrictor 37. The other extreme is described by damping force characteristic "2", representing restrictor 37 without damping device 79. Once the volumetric flow rate Q has reached the threshold and Δp appears at restrictor 37, restrictor 37 begins to take effect, and the damping force increases very gradually. This increase in damping force can optionally level off again by means of the pressure relief valve.

[0055] By using the damping device 79 with a free travel of 99%, a rounded damping force characteristic that improves comfort, conforming to damping force characteristic "3," can be achieved. When the damping device 79 does not have a free travel of 99, the damping force follows damping force characteristic "4." The damping force curve is significantly shallower. If the damping device 79 operates under a certain preload or prestress—that is, even at the minimum diameter of the valve body 35, the damping device not only functions but also carries damping force—then a shift in damping force characteristic "4" will occur. The illustrative damping force characteristic "5" illustrates this working principle.

[0056] List of reference numerals

[0057] 1 Damping valve device

[0058] 3 Vibration dampers

[0059] 5 First damping valve

[0060] 7 Damping valve body

[0061] 9 Piston rod

[0062] 11 Cylinder Block

[0063] 13 Working chamber on the piston rod side

[0064] 15. Working chamber away from the piston rod

[0065] 17 Through passage

[0066] 19 Through passage

[0067] 21 Valve disc

[0068] 23 Valve disc

[0069] 25 Tension stop

[0070] 27 Piston rod guide

[0071] 29 Valve support

[0072] 31 Elastomer Components

[0073] 33 Annular groove

[0074] 35 Valve body

[0075] 37 Restricted Body

[0076] 39 Inner wall

[0077] 41. Return spring

[0078] 45 side surface

[0079] 47 Valve seat surface

[0080] 49 Valve seat surface

[0081] 51 Support level

[0082] 53 Support level

[0083] 55 Lateral clearance

[0084] 57 Flow cross section

[0085] 59 Outlines

[0086] 61. Restricted Section

[0087] 63 branches

[0088] 65 branches

[0089] 67 Pivot support

[0090] 69 Support pins

[0091] 71 Support ring

[0092] 73. Acceptance opening

[0093] 75 Support opening

[0094] 77 Support opening

[0095] 79 Damping device

[0096] 81 Elastomer Body

[0097] 83 Web

[0098] 85 Pressure Chamber

[0099] 87 Side Surface

[0100] 89. Groove bottom surface

[0101] 91. Groove sidewall

[0102] 93. Groove sidewall

[0103] 95 Inflow Opening

[0104] 97 Outflow Channel

[0105] 99 Free Travel

[0106] 101 Cover

[0107] 103 Opening

[0108] 105 Damping medium volume

[0109] 107 Pressure Chamber

[0110] 109 Top Side

[0111] 111 Circular Web

[0112] 113 Annular web

[0113] 115 gap

[0114] 117 Restricted opening

[0115] 119 Displacement body

[0116] 121 Return spring

[0117] 123 Seals

Claims

1. A limiting body for a vibration damper (3), comprising a valve body (35) of variable diameter, the valve body being guided by a valve support (29) and, starting from a flow-through position, the valve body assuming a limiting position by radial closing movement toward a flow-guided surface (39) according to the flow velocity of the damping medium within the limiting body (37), wherein, The closing movement of the valve body (35) is controlled by at least one damping device (79), wherein the damping device (79) is supported on the valve support (29), and wherein the damping device (79) is formed of at least one elastomer body (81).

2. The limiting body as claimed in claim 1, wherein, The damping device (79) begins to function after the free travel (99) of the valve body (35).

3. The limiting body as claimed in claim 1, wherein, The damping device (79) begins to function from the initial position of the valve body (35).

4. The limiting body as described in any one of claims 1 to 3, wherein, The valve body (35) is controlled by a plurality of damping devices (79), which act at different diameters of the valve body (35).

5. The limiting body as claimed in claim 1, wherein, The damping device (79) is implemented as a hydraulic damping device.

6. The limiting body as claimed in claim 5, wherein, The elastomer body (81) is implemented as a hollow body capable of being filled with a damping medium.

7. The limiting body as described in any one of claims 1 to 3, wherein, The damping device (79) is supported on the cover (101) of the valve support (29).

8. The limiting body as claimed in claim 5, wherein, The valve body (35) and the valve support (29) are formed in a pressure chamber (107) that is compressed during the expansion movement of the valve body.

9. The limiting body as claimed in claim 8, wherein, The pressure chamber (107) is defined by the top side (109) of the valve body (35) and a portion of the sidewall (13) of the annular groove (33).

10. The limiting body as claimed in claim 5, wherein, The valve support (29) has the hydraulic damping device (79) having at least one pressure chamber (107) filled with a damping medium, and in the pressure chamber, a displacement body (119) controlled by the valve body (35) performs working movement.

11. The limiting body as claimed in claim 10, wherein, The pressure chamber (107) is formed by the valve body (35).

12. The limiting body as claimed in claim 11, wherein, The displacement body (119) is designed as a connecting rod mounted on the valve support (29).

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