Damping valve device for vibration dampers

Abstract

The present invention relates to a damping valve device (1) for a vibration damper (13), the damping valve device having progressive damping force characteristics, the damping valve device including a throttling point (37) connected to an annular, diameter-variable valve body (35), the valve body being supported in an annular groove (33) of a valve carrier (29), wherein the annular groove (33) and the inner surface (61) of the valve body (35) form a pressure chamber (55), wherein the valve body (35) moves radially toward the guide surface (39) in the closing direction as the flow velocity of the damping medium in the throttling point (37) increases, wherein at least one inflow channel (57) into the pressure chamber is fitted with a valve device (65), wherein the valve device (65) changes to a closed position as the flow velocity in the valve device (65) increases.

Description

Technical Field

[0001] This invention relates to a damping valve device for a vibration damper. Background Technology

[0002] A damping valve device for a vibration damper is known from the general type DE 10 2016 210 790A1, wherein the damping force characteristics are affected by a throttling point connected to an annular valve body, which can be switched to a throttling position, wherein the annular valve body moves radially in the closing direction as the flow velocity of the damping medium in the annular groove increases until a defined minimum flow cross section is achieved.

[0003] Tests have shown that the pressure levels generated in vibration dampers at maximum throttling can reach dangerous levels. To address this, a prior German patent proposed a pressure relief valve connected in parallel with the throttling point. However, this solution may necessitate the introduction of a separate flow path, which may not provide sufficient structural space under unfavorable structural space conditions (e.g., a combination of a small cylinder diameter and a large piston rod diameter). Summary of the Invention

[0004] The purpose of this invention is to solve the problems known in the prior art.

[0005] This objective is achieved by equipping at least one inflow channel into the pressure chamber with a valve device, wherein the valve device changes to a closed position as the flow velocity in the valve device increases.

[0006] In addition to the negative pressure within the throttling point, an expansion force can be generated on the valve body through the inflow channel. If this additional expansion force is reduced or cut off, overpressure in the damping valve device or vibration damper can be prevented. Another advantage is that the regulating parameters for throttling valves and valve devices are the same, namely the flow velocity of the damping medium.

[0007] In the first embodiment, the inflow opening of the inflow channel constitutes a component of the valve device. This variant offers the advantage that the valve device can be arranged outside the valve carrier, allowing the use of a standard valve carrier that can optionally be fitted with the valve device.

[0008] The most striking feature of the entire damping valve assembly is its remarkably simple structure. To achieve this, the valve assembly has at least one valve disc that performs axial closing motion. This is accomplished, for example, by a simple combination of a spacer and at least one valve disc acting on the inflow passage.

[0009] To support the overall characteristics of the damping valve device, the device includes a spring element that causes the valve body to return to its original position and possesses a spring force. This spring force enables the valve body to return to its original position towards the annular groove in the closed position. This clearly defines the operational behavior of the damping valve device.

[0010] It can be proposed that the valve carrier has a closing surface for at least one valve disc in the valve assembly. Alternatively, however, it is also possible that a valve body with a variable diameter, together with a resilient valve disc, constitutes the valve assembly. A radially expanding valve body is achieved, and the closing surface is also radially expanded on the valve body. Therefore, the lever arm of the pressure acting on the valve disc becomes larger, which causes the valve assembly to shift toward the closed position.

[0011] In another advantageous design of the invention, the valve body surrounds the valve carrier on the outside. This provides a larger area for arranging the closure surface for the valve device on the valve body.

[0012] In a particularly simple structural form, the valve body has a flexible bending region, which is an integral part of the valve assembly. This flexible bending region performs the function of at least one valve disc, thereby eliminating the need for the valve disc itself.

[0013] In another embodiment of the invention, the outflow opening of the inflow channel into the pressure chamber is fitted with a valve device. The advantage of this variant is that all relevant components of the damping valve are held or assembled within a valve carrier, preferably in such a way that at least one valve disc, together with the valve body, forms a valve device within an annular groove. Attached Figure Description

[0014] The present invention will be described in detail with the aid of the following accompanying drawings.

[0015] In the attached diagram:

[0016] Figure 1 A portion of the vibration damper is shown;

[0017] Figure 2 Show Figure 1 Damping valve device;

[0018] Figure 3 Show Figure 2 The characteristic curve of the damping force;

[0019] Figures 4 to 6 Show Figure 2 Alternative variants; Detailed Implementation

[0020] Figure 1A damping valve device 1 is shown for a vibration damper 3 of any structural configuration (shown only partially). Preferably, 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.

[0021] The damping valve body 7 divides the cylinder 11 of the vibration damper into a working space on the piston rod side and a working space away from the piston rod, both of which are filled with damping medium. In the damping valve body 7, the through passages for their respective flow directions are implemented with different pitch circles (Teilkreis). The design of the through passages is only considered exemplary. The outlet side of the through passages 17; 19 is at least partially covered by at least one valve disc 21; 23.

[0022] Additionally, the vibration damper has a stroke limiter 25 that abuts against a stop surface (e.g., piston rod guide 27) on the cylinder side after the defined extension movement of the piston rod 9.

[0023] The travel limiter 25 includes a valve carrier 29, which is directly fixed to the piston rod by a form-fit connection. An annular elastomeric element 31 is exemplarily placed on the top surface of the valve carrier 29, and this annular elastomeric element is held in place by a small radial preload even during the vibratory movement of the piston rod 9. The elastomeric element 31 acts as an additional support spring on the stop surface from the stop point.

[0024] The valve carrier 29 has a surrounding annular groove 33 in which a valve body 35 of variable diameter is carried. This valve body 35 is radially elastic and forms a throttling point 37 as part of the damping valve device 1. The valve body 35 forms a throttling point with the inner wall 39 of the cylinder 11, where the inner wall 39 forms a guide surface. In principle, the invention can also be implemented in a carrier disc independent of a stroke limiter. Furthermore, although the damping valve 5 in the piston 7 is advantageous, it is not necessarily required.

[0025] The valve body 35 carries a surrounding spring element on its outer side, which functions as a return spring 41, for example, in a fixed ring configuration. A variable throttling section 45 exists between the inner wall 39 and the outer surface 43 of the valve body 35, which generates additional damping force.

[0026] When the piston rod speed is within the first operating range (e.g., less than 1 m / s), the throttling point 37 is fully open. Therefore, the damping force is generated only from the through-passages 17 and 19 connected to the valve discs 21 and 23. Upon inflow into the valve discs 21 and 23, the valve discs 21 and 23 are lifted from their seat surfaces 47 and 49. This lifting motion is correspondingly limited by the support discs 51 and 53.

[0027] In a second operating range, with a piston rod speed greater than the limit speed of the first operating range (i.e., greater than the 1 m / s given exemplarily), the valve body 35 transitions to a throttling position and performs a closing motion in the direction of the guide flow surface 39. Due to the high flow velocity of the damping medium, a negative pressure is formed in the throttling point 37, which is formed as an annular gap, causing the valve body 35 to expand radially. However, to prevent blockage of the throttling point 37 under any circumstances, a defined minimum flow cross-section is maintained by a return spring 41. Alternatively or additionally, the valve body may have an axially extending portion on its surface 43, thereby similarly achieving a defined minimum flow cross-section when the valve body is applied to the inner wall.

[0028] Figure 2 A portion of the damping valve device 1 is shown, particularly the valve carrier 29 with the valve body 35. As can be seen in the enlarged view, the valve carrier 29, with its annular groove 33, and the valve body 35, with its inner surface 54, form a pressure chamber 55, which has an inflow channel 57 and an outflow channel 59. The outflow channel may be formed by an axial hole or also by an annular gap between the cover surface 61 of the valve body 35 and the sidewall 63 of the annular groove 33 facing the cover surface 61.

[0029] exist Figure 2 In this configuration, the valve body 35 occupies the smallest diameter, resulting in the largest opening section 45 for the throttling point 37. This state exists when the aforementioned velocity of the piston rod is, for example, 1 m / s and the filling of the associated pressure chamber has not yet caused the valve body 35 to expand.

[0030] also, Figure 2 As shown, at least one inflow passage 57 of the pressure chamber is fitted with a valve device 65, which transitions to a closed position as the flow velocity within the valve device 65 increases. For this purpose, the inflow opening 67 of the inflow passage 57 constitutes a component of the valve device 65. Another component of the valve device consists of at least one resilient valve disc 69 that performs an axial closing motion, which is coupled to the valve carrier 29 by at least one spacer gasket 71 connected upstream. For example, fastening can be achieved by means of a commercially available retaining ring (not shown). The valve carrier 29 provides a protruding valve seat surface 73 for the valve disc 69 outside the annular groove 33. A negative pressure is created within the annular gap 75 between the valve carrier 29 and the valve disc 69, depending on the flow velocity, which causes the valve device 65 to close. The term "closing motion" does not necessarily mean a complete seal, but can also simply reduce the volumetric flow rate entering the pressure chamber 55.

[0031] Preferably, the valve assembly 65 is only effective when the valve body 35 brings the throttle valve 37 to its maximum throttling position and the vibration damper 3 reaches a critical pressure level. The precise point of use depends on the specific vibration damper 3 and / or its application in the vehicle. The spring element 41 is preloaded to a greater extent when the valve body 35 expands radially toward the guide surface 39 or the inner wall. The spring element that returns the valve body 35 to its return motion has a spring force F. F The spring force resists the pressure F within the pressure chamber 55 in the closed position of the valve device 65. D The valve body 35 is reset in the direction of the annular groove 33. Here, the damping medium is discharged from the pressure chamber 55 through the outlet channel 59 by means of the diameter reduction portion of the valve body 35 in the direction of the annular groove 33.

[0032] Figure 3 The effect of valve device 65 is shown. The dashed damping force characteristic curve below describes the damping force characteristics of damping valve 5. The parabolic rise indicates the operating point of throttle valve 37, whose damping force characteristic curve rises significantly more than that of damping valve 5. When the critical value Δp of damping valve device 1 or vibration damper 3 is reached, inflow channel 57 is closed and throttle valve 37 reopens under the restoring force of spring element 41. However, the damping force does not return to the damping force of damping valve 5, but rather to a higher damping force level, which can be represented by the dip in the characteristic curve. The combined action of throttle valve 37 and damping valve 5 can be adjusted by the size of spring element 41.

[0033] According to Figure 4 In this embodiment, a valve body 35 with a variable diameter, together with a resilient valve disc 69, constitutes a valve device 65. For this purpose, a valve seat surface 73 of the valve device 65 is provided on the valve body 35. Furthermore, the valve body 35 surrounds the valve carrier 29 on its outer side and thus radially overlaps with the outer cover surface 77 of the valve carrier 29. This arrangement allows the valve seat surface 73 to be moved radially inward when needed.

[0034] The axial displacement of the valve body 35 caused by the inner surface 54 inclined toward the pressure chamber 55 also closes the annular gap 79 extending between the overlapping section 81 of the valve body 35 and the valve carrier 29. When the valve device 65 switches to the closing motion, all possible inflow sections are closed by the valve disc 69 from the inflow direction.

[0035] As the valve body 35 expands, the diameter of the valve seat surface 73 increases due to the higher flow velocity in the throttle valve 37. Consequently, the distance between the valve seat surface 73 and the outer diameter of the spacer 71 also lengthens, increasing the lever arm of the negative pressure within the valve assembly 65 due to the higher instantaneous flow velocity. Subsequently, the valve disc 69 rotates to the closed position more quickly.

[0036] According to Figure 5 In this embodiment, the valve body 35 has a flexible region 83, which is a component of the valve device 65. Here, the valve body 35 extends radially inward such that the flexible region 83 overlaps with the inflow channel 57, wherein there is an axial gap between the cover surface 77 of the valve carrier 29 and the flexible region 83. The flexible region 83 of the valve body 35, together with the valve carrier 29, constitutes the valve device 65. Therefore, no additional components are required. The pressure F within the pressure chamber 55... D This causes the closing motion, and the spring force F F This causes the valve device 65 to open.

[0037] Upon inflow to the throttling point 37, a radial diameter expansion and axial displacement of the valve body 35 toward the sidewall 63 occur. If the flow between the annular gap 79 of the elastic region 83 and the cover surface 77 of the valve carrier 29 exceeds a critical velocity, the elastic region moves toward the cover surface 77 and closes or restricts at least some additional damping medium from flowing into the pressure chamber 55.

[0038] With the help of Figure 6 It should be shown that in the damping valve device 1, the outflow opening 85 of the inflow channel 57 into the pressure chamber can also be fitted with the valve device 65. The valve carrier 29 is axially divided into two parts, precisely pre-tightening the valve disc 73 and the spacer gasket 71 by its upper part 29A and lower part 29B. Thus, an annular gap 87 exists between the sidewall 89 of the annular groove 33 and the valve disc 69. There is a radial overlap between the valve disc 69 and the cover surface 91 of the valve body, which is maintained even when the valve body is at its maximum expansion. When the damping medium appears on the bottom side of the valve disc 69 via the inflow channel 57, the valve disc 69 deforms toward the valve body 35. The pressure chamber is radially closed outward by means of the seal 93. The damping medium flows toward the pressure chamber 55 around the valve disc 69, thereby generating a negative pressure on the top side of the valve disc, which assists the elastic adjustment movement of the valve disc 69 until the valve disc is in its maximum position against the cover surface 91 of the valve body 35 and at least reduces the further inflow of the damping medium into the pressure chamber 55. Thus, the valve disc 69 and the valve body 35 together constitute the valve device 69.

[0039] List of reference numerals

[0040] 1 Damping valve device

[0041] 3 Vibration dampers

[0042] 5 First damping valve

[0043] 7 Damping valve body

[0044] 9 Piston rod

[0045] 11 Cylinder Block

[0046] 13 Working chamber on the piston rod side

[0047] 15. Working chamber away from the piston rod

[0048] 17 Through passage

[0049] 19 Through passage

[0050] 21 Valve disc

[0051] 23 Valve disc

[0052] 25 Travel limit switch

[0053] 27 Piston rod guide

[0054] 29 Valve Carrier

[0055] 31 Elastomer Components

[0056] 33 Annular groove

[0057] 35 Valve body

[0058] 37 Throttling Points

[0059] 39 Inner wall

[0060] 41 Spring element

[0061] 43 Surface

[0062] 45 Throttling section

[0063] 47 Valve seat face

[0064] 49 Valve seat face

[0065] 51 Support level

[0066] 53 Support level

[0067] 54 Surface

[0068] 55 Pressure Chamber

[0069] 57 Inflow Channel

[0070] 59 Outflow Channel

[0071] 61. Cover

[0072] 63 Sidewall

[0073] 65 Valve Device

[0074] 67 Inflow Opening

[0075] 69 Valve disc

[0076] 71 Spacer Washer

[0077] 73 Valve seat face

[0078] 75 Annular gap

[0079] 77. Cover

[0080] 79 Annular gap

[0081] 81 Overlapping Sections

[0082] 83 Bending elastic region

[0083] 85 outflow opening

[0084] 87 Annular gap

[0085] 89 Sidewalls

[0086] 91 Cover

[0087] 93 Seals

Claims

1. A damping valve device (1) for a vibration damper (3), the damping valve device having progressive damping force characteristics, the damping valve device including a throttling point (37) connected to an annular, diameter-variable valve body (35), the valve body being supported in an annular groove (33) of a valve carrier (29), wherein the annular groove (33) and the inner surface (61) of the valve body (35) form a pressure chamber (55), the pressure chamber having at least one inflow channel (57), wherein, The inner wall of the cylinder (11) of the vibration damper forms a guide surface (39), and the valve body (35) moves radially toward the guide surface (39) in the closing direction as the flow velocity of the damping medium in the throttling point (37) increases. The valve body (35) is characterized in that at least one inflow channel (57) into the pressure chamber is equipped with a valve device (65), wherein the valve device (65) changes to a closed position as the flow velocity in the valve device (65) increases.

2. The damping valve device according to claim 1, characterized in that, The inflow opening (67) of the inflow channel (57) constitutes a component of the valve device (65).

3. The damping valve device according to claim 1, characterized in that, The valve device (65) has at least one valve disc (69) that performs axial closing motion.

4. The damping valve device according to claim 2, characterized in that, The valve device (65) has at least one valve disc (69) that performs axial closing motion.

5. The damping valve device according to any one of claims 1 to 4, characterized in that, The spring element (41) that causes the valve body (35) to perform a reset movement has a spring force FF, which enables the valve body (35) to perform a reset movement toward the annular groove (33) in the closed position of the valve device (65).

6. The damping valve device according to claim 3 or 4, characterized in that, The valve body (35) with a variable diameter, together with the valve disc (69), constitutes the valve device (65).

7. The damping valve device according to any one of claims 1 to 4, characterized in that, The valve body (35) surrounds the valve carrier (29) on the outside.

8. The damping valve device according to claim 7, characterized in that, The valve body (35) has a bending elastic region (83), which is a component of the valve device (65).

9. The damping valve device according to claim 8, characterized in that, The bending elastic region (83) of the valve body (35) together with the valve carrier (29) constitutes the valve device (65).

10. The damping valve device according to any one of claims 1 to 4, characterized in that, The valve device (65) is installed at the outlet opening (85) of the inflow channel (57) into the pressure chamber (55).

11. The damping valve device according to claim 3 or 4, characterized in that, The at least one valve disc (69) together with the valve body (35) forms the valve device within the annular groove (33).

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