Adjustable damping valve device for a vibration damper

Abstract

Damping valve device (1) for a vibration damper (3), comprising a valve carrier (9) with a circumferential annular groove (11) in which a diameter-variable annular valve element (13) is arranged, which, together with a flow guide surface (15) for flowing damping medium, forms the throttling point (17), the throttling cross-section of which decreases with increasing flow velocity of the damping medium within the throttling point (17), wherein the circumferential annular groove (11) forms a pressure chamber (25) filled with damping medium, so that a radially outward actuating force acts on the valve element (13), wherein the pressure chamber (25) has a connection (29; 31) to at least one working chamber (33) of the vibration damper (3), wherein the cross-section of the connection (29; 31) to the pressure chamber (25) is adjustable, characterized in that the connection has a valve element (35) which is connected on one side to the connection (29;31) to the pressure chamber (25) and on the other hand to a control chamber (37), wherein the pressure inside the control chamber (37) is adjustable via an actuating means (39) and the valve carrier (11) has an annular space (43), wherein the annular space (43) forms the control chamber (37) and the valve element (35) is formed by an annular body.;

Description

[0001] The invention relates to an adjustable damping valve device according to the preamble of claim 1.

[0002] From DE 10 2020 209 101 A1, an adjustable damping valve device for a vibration damper is known. A drain opening or a bypass to the drain opening can be controlled via an actuating means. The ratio of the cross-sectional areas of the drain opening to an inlet opening determines the pressure level within a pressure chamber, the pressure of which exerts a radial pressure force on an annular valve element.

[0003] DE 10 2020 209 109 A1 also relates to an adjustable damping valve device. During adjustment, a radial mechanical actuating force is applied to a valve ring within an annular pressure chamber via a spreading tool.

[0004] The object of the present invention is to provide a further solution for adjusting the damping valve device.

[0005] The problem is solved by the features of claim 1.

[0006] The adjustment function of a damping valve assembly that is not otherwise adjustable can be upgraded by combining a valve element, control chamber, and actuator. A very simple component is used as the valve element, which is also easy to install.

[0007] In a further advantageous embodiment, the control chamber is implemented in an additional disc of the valve carrier. This measure serves to standardize the damping valve assembly.

[0008] With regard to a simple spatial geometry, the control chamber is formed by a blind opening of the additional disc facing the valve carrier and a cover side of the valve carrier.

[0009] Regarding the pressure support for adjusting the valve element, there is the possibility that the control chamber is connected to one of the working spaces.

[0010] Alternatively, the control chamber can be filled with a constant volume of control medium, which is displaced via the actuating device within the control chamber.

[0011] The invention allows for an overload function to be implemented in the damping valve assembly by having the actuating means control the cross-section of a drain opening in the pressure chamber, wherein the actuating means and / or the control chamber is equipped with a pressure limiting device. If the pressure inside the pressure chamber rises above a predetermined level, the effective cross-section of the drain opening is increased, thereby limiting the maximum damping force of the damping valve assembly.

[0012] The pressure limiting device can thus be easily formed by a movable wall as part of the control chamber.

[0013] The following description of the figures will be used to explain the invention in more detail.

[0014] It shows: Fig. 1 Adjustable damping valve device with constant control medium volume Fig. 2 Alternative variant to Fig. 1.

[0015] The Fig. Figure 1 shows an adjustable damping valve assembly 1 for a vibration damper 3, which comprises a working cylinder 5 filled with damping medium, in which a piston rod 7 is guided axially for movement. The damping valve assembly 1 is arranged on the piston rod 7, often in combination with a piston, known per se, equipped with damping valves.

[0016] A main component of the damping valve assembly 1 is formed by a valve carrier 9, which has an annular groove 11 in which an annular valve element 13 is guided. The valve element 13 can be, for example, radially elastic or multi-segmented and forms a throttling point 17 with a flow guide surface 15, which is formed by an inner wall of the working cylinder 5.

[0017] Depending on the flow velocity of the damping medium within the throttling point 17, a pressure drop is created, which generates a radial expansion force on the valve element 9 in the direction of the flow guide surface 15. A mechanical stop 19 and / or a return spring 21 define a minimum throttling cross-section between an outer surface 23 of the valve element 13 and the flow guide surface 15.

[0018] The damping valve assembly 1 has a pressure chamber 25 formed by the walls of the annular groove 11 and an inner outer surface 27 of the valve element 13. The pressure chamber 25 is connected to a working chamber 33 of the working cylinder 5 via at least one inlet port 29 and at least one outlet port 31. The pressure within the pressure chamber 25 exerts a radially outward actuating force on the valve body 13. The inlet port 29 and the outlet port 31 form a hydraulic connection, the cross-sectional ratio of which determines the damping force characteristic of the damping valve assembly 1.

[0019] The damping valve device 1 has a valve element 35 which is connected on one side to the connection 29; 31 to the pressure chamber 25 and on the other side to a control chamber 37, wherein the pressure inside the control chamber 37 is adjustable via an actuating means 39.

[0020] For this purpose, the valve carrier 9 has an annular space 43, which forms part of the control chamber 37. The valve element 35 in the control chamber 37 is also formed by a radially elastically expandable ring body, e.g., a sealing ring. The valve carrier 9 can be designed as already known from the prior art, since the control chamber 37 is formed in an additional disk 41 of the valve carrier 9. A hydraulic transition 47 exists between the annular space 43 of the valve carrier 9 and a second part 45 of the control chamber 37 inside the piston rod 7.

[0021] The control chamber 37 is formed by a blind opening in the auxiliary disc 41 facing the valve carrier 9 and a cover face 49 of the valve carrier 9. Consequently, the auxiliary disc 41 can even be designed as a simple stamped part. The control chamber 37 extends from a through-opening 51 within the auxiliary disc 41 to its inner diameter 53. The drain opening 31 is axially overlapping with the annular space 43, but radially outside the valve element 35 in an annular region.

[0022] In this embodiment, the control chamber 37 is filled with a constant volume of control medium, which is displaced within the control chamber 37 via the actuating means 39.

[0023] Within the piston rod 7, an axially movable displacement rod 39 is guided as an actuating means, forming a wall of the control chamber 37 within the piston rod at its end face. The displacement rod 39 is sealed by at least one ring seal 55, ensuring a constant volume of control medium within the control chamber 37. An axial retraction movement of the displacement rod 39 into the partial chamber 45 within the piston rod 7 causes a radial expansion movement of the valve element 35 due to the incompressibility of the control medium. This expansion movement narrows the cross-section of the discharge opening 31, thereby increasing the damping force characteristic of the damping valve assembly 1.

[0024] An extension movement of the displacement rod 39 causes the partial space 45 within the piston rod 7 to increase in size. The inherent elasticity of the valve element 35 causes a flow of control medium from the partial space within the additional disc 41. This increases the effective cross-section of the outlet opening 31, resulting in a reduction of the damping force characteristic.

[0025] Optionally, the actuating element 39 and / or the control chamber 37 may be equipped with a pressure limiting device 57. In this specific example, the pressure limiting device 57 is formed by a movable wall 59 as part of the control chamber 45. The displacement rod 39 has a spring-loaded insert 61, which is guided axially within the displacement rod 63. The pressure within the pressure chamber 25 also acts on the valve element 35. This results in a pressure transmission from the pressure chamber 25 to the control chamber 37. A pressure level above a limit value accordingly leads to a load on the insert 61 within the displacement rod 39, which can deflect against the force of a preload spring 63. This allows the volume of the control chamber 37 to increase and compensate for the peak pressure.The cross-section of the drain opening is gradually opened by the valve element, thereby limiting the peak pressure within the pressure chamber 25.

[0026] The damping valve device 1 according to Fig. 2 corresponds in its mode of operation and basic structure to the version according to Fig. 1. In contrast, the control chamber 37 is connected to the working chamber 33. For this purpose, the piston rod 7 has a radial channel 65 which, together with the actuating means 39, forms a slide valve 67.

[0027] The valve element 35 comprises two coaxial sealing rings with different diameters. The purpose of this design is to ensure that the pressurized area of ​​the valve element 35 is larger in the direction of the control chamber 37 than in the direction of the outlet opening 31. In principle, this design principle could also be achieved with a one-piece valve element 35. Depending on the cross-section of the gate valve 67, a pressure level builds up within the control chamber 37, which leads to an expansion of the valve element 35 and thus to a reduction in the cross-section of the outlet opening 31. The design according to [reference missing] is also possible. Fig. 2 with a pressure limiting device 57 according to Fig. 1 can be combined. Reference sign 1 Damping valve device 3 vibration dampers 5 working cylinders 7 Piston rod 9 valve carriers 11 Ring groove 13 Valve element 15 Flow guide surface 17 Throttle point 19 attacks 21 Return spring 23 outer surface of the valve element 25 pressure chamber 27 inner surface area of ​​the valve element 29 Inlet opening 31 Drain opening 33 Workroom 35 Valve element 37 Tax Chamber 39 Actuators 41 Additional disc 43 Ring space 45 second part of the tax chamber 47 hydraulic transition 49 Cover page 51 Passage opening 53 inner diameter 55 ring seal 57 Pressure relief device 59 movable wall 61 deployment 63 Preload spring 65 Radial canal 67 Slide valve

Claims

[1] Damping valve device (1) for a vibration damper (3), comprising a valve carrier (9) with a circumferential annular groove (11) in which a diameter-adjustable annular valve element (13) is arranged, which, together with a flow guide surface (15) for flowing damping medium, forms the throttle point (17), the throttle cross-section of which decreases with increasing flow velocity of the damping medium within the throttle point (17), wherein the circumferential annular groove (11) forms a pressure chamber (25) filled with damping medium, so that a radially outwardly directed actuating force acts on the valve element (13), wherein the pressure chamber (25) has a connection (29; 31) to at least one working chamber (33) of the vibration damper (3), wherein the cross-section of the connection (29; 31) to the pressure chamber (25) is adjustable, characterized byin that the connection has a valve element (35) which is connected on the one hand to the connection (29; 31) to the pressure chamber (25) and on the other hand to a control chamber (37), wherein the pressure within the control chamber (37) can be adjusted via an adjusting means (39) and the valve carrier (11) has an annular space (43), wherein the annular space (43) forms the control chamber (37) and the valve element (35) is formed by an annular body. [2] Damping valve device according to claim 1, characterized by that the control chamber (37) is designed in an additional disc (41) of the valve carrier (9). [3] Damping valve device according to claim 2, characterized by that the control chamber (37) is formed by a blind hole opening of the additional disc (41) facing the valve carrier (9) and a cover side (49) of the valve carrier (9). [4] Damping valve device according to at least one of claims 1 to 3, characterized bythat the control chamber (37) is connected to one of the working chambers (33). [5] Damping valve device according to at least one of claims 1 to 3, characterized by that the control chamber (37) is filled with a constant control medium volume, which is displaced within the control chamber (37) via the actuating means (39). [6] Damping valve device according to at least one of claims 1 to 5, characterized by that the adjusting means (39) controls the cross-section of a discharge opening (31) of the pressure chamber (25), wherein the adjusting means (39) and / or the control chamber (37) is designed with a pressure limiting device (57). [7] Damping valve device according to claim 6, characterized by that the pressure limiting device (57) is formed by a movable wall (59) as part of the control chamber (37).

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