Damping valve device with progressive damping force characteristic

Abstract

Damping valve device (1) for a vibration damper (3), comprising a throttle point (31) in conjunction with a valve element (29) which can be converted from a flow position to a throttle position depending on the flow velocity of a damping medium within the throttle point (31), wherein the valve element (29) is arranged as a ring element with a variable diameter within an annular groove (27) of a valve carrier (25), wherein the valve element (29) and the annular groove (27) have mutually facing cylindrical surfaces (55;61) form a pressure chamber (63), wherein the valve element (29) is positioned by a centering (91) at a radial distance to an annular groove base surface (61) of the annular groove (27) and the distance is adjustable by means of an adjusting device (93), characterized in that the damping valve device (1) is arranged on a piston rod (9) of the vibration damper (3) and an actuator rod (95) of the adjusting device (93) is guided within the piston rod (9) and radially movable transmission rods (97) are arranged between the valve element (29) and the actuator rod (95), the end faces (99) of which pointing towards the valve element (29) form the centering (91).

Description

[0001] The invention relates to a damping valve device with a progressive damping force characteristic according to the preamble of patent claim 1.

[0002] DE 10 2016 210 790 A1 describes a damping valve device for a vibration damper, comprising a first damping valve that transitions into a through-opening operating position in a first operating range with increasing flow velocity of a damping medium. The first damping valve is formed, for example, by a piston valve or a base valve of the vibration damper. A second operating range with a progressive damping force characteristic of the vibration damper is influenced by a throttle point in conjunction with a valve body that can be transferred from a through-opening position to a throttle position, independent of the stroke position of a piston rod of the vibration damper, depending on the flow velocity within the throttle position, wherein the valve body moves in the closing direction with increasing flow velocity of the damping medium.This creates an additional damping force that eliminates the need for a conventional pull or push stop, which is only effective in one end position of the piston rod.

[0003] The throttle point and the damping valve are hydraulically arranged in series, with the valve body being designed as a ring element with a variable diameter that executes a radial closing movement in the direction of a flow guide surface, where a defined minimum flow cross-section is maintained.

[0004] In DE 10 2019 212 966 A1 it is proposed that the ring element, which can be changed in diameter, is additionally supported by a compressive force within a pressure chamber formed by an annular groove.

[0005] The adjustable-diameter ring element is guided radially in the annular groove of the valve carrier, at least over a large circumferential area. This results in undefined operating behavior, particularly when activating the damping valve device.

[0006] The older DE 10 2021 201 441 A1 describes a damping valve device in which the valve carrier has an internal centering within a pressure chamber coaxial with the valve element. This defines the initial position of the valve element.

[0007] The generic document DE 10 2020 209 121 A1 describes a damping valve device in which a maximum passage position of the valve element can be adjusted by means of adjusting screws which are supported on the valve carrier of the damping valve device.

[0008] In DE 10 2020 209 101 A1, a flow connection of a pressure chamber of the damping valve device can be controlled by means of an actuating element within the piston rod in order to influence the pressure level in the pressure chamber via the throttling effect of the actuating element.

[0009] The object of the present invention is to further develop the function of internal centering.

[0010] The problem is solved by the features of patent claim 1.

[0011] The adjustability of the distance can be used to compensate for unavoidable component tolerances within the damping valve devices. Even a small adjustment range would be sufficient for this.

[0012] However, it is also possible to vary the activation point of the damping valve device over a larger functional range. The activation point is determined by the maximum size of the throttle cross-section of the damping valve device. The smaller the maximum size, the lower the flow velocity within the throttle can be, which leads to an expansion movement of the valve element due to the buildup of reduced pressure within the throttle.

[0013] The actuator rod can be moved manually or, for example, by means of an electromagnetic actuator.

[0014] The transmission rods are loosely inserted and clamped between the valve element and the actuator rod. This allows for compensation of relative movements between all components involved in the adjustment movement. This design also simplifies the installation of the damping valve device.

[0015] Another means of simplifying the construction of the damping valve device is that the transmission rods are guided within windows of the piston rod.

[0016] The preferred adjustment movement of the actuator rod is an axial displacement within the piston rod. To implement the axial adjustment movement of the actuator rod and centering, a conical connection is provided between the actuator rod and the transmission rods.

[0017] Optionally, the maximum throttle position of the valve element can be determined by a stop on the carrier side, whose effective diameter is adjustable for the valve element. This allows both the minimum and maximum throttle cross-section of the damping valve device to be adjusted.

[0018] For this purpose, the stop can be adjusted using an adjusting element, which can also be manually or, for example, electromagnetically.

[0019] For example, a cover plate of the valve carrier forming the stop is made up of several parts and has at least one radial parting line between the cover plate parts.

[0020] To minimize any possible leakage paths, the cover plate has a cover cap that at least partially covers the joint.

[0021] A particularly compact design of a combined adjustment of the throttle cross sections is achieved by guiding the actuator rod within the actuating element for the stop.

[0022] The invention will be explained in more detail with reference to the following figures. It shows: Fig. 1 Section of a vibration damper in the area of ​​the damping valve device Fig. 2 Damping valve device according to Fig. 1 in detail

[0023] The Fig. Figure 1 shows a damping valve device 1 for a vibration damper 3 of any design (shown only in part). In addition to the damping valve device 1, the vibration damper 3 comprises a first damping valve 5 with a damping valve body designed as a piston 7, which is attached to a piston rod 9.

[0024] The damping valve body 7 divides a cylinder 11 of the vibration damper into a working chamber 13; 15 on the piston rod side and a working chamber 13; 15 on the piston rod side, both filled with damping medium. The damping valve body 7 contains passages 17; 19, each for a flow direction, on different pitch circles. The design of the passages 17; 19 is only an example. One outlet side of the passages 17; 19 is at least partially covered by at least one valve disc 21; 23.

[0025] For example, a valve carrier 25 of the damping valve device 1 is fixed directly to the piston rod 9. The valve carrier 25 has a circumferential annular groove 27 in which a valve element 29 with variable diameter is guided ( Fig. 2). This valve element 29 is radially movable and forms a valve body for a throttle point 31 as part of the damping valve device 1. The valve element 29 forms the throttle point 31 with an inner wall of the cylinder 11, the inner wall representing a flow guide surface 33.

[0026] The valve element 29 is equipped with a return spring 35, as shown in the Fig. 2 is shown enlarged. Between the flow guide surface 33 and an outer surface 37 of the valve element 29 there is a variable throttle cross-section 39, which generates an additional damping force for the damping valve 5.

[0027] At a piston rod speed in a first operating range, e.g., less than 1 m / s, the throttle point 31 is fully open. The damping force is then generated only by the passages 17; 19 in conjunction with the valve discs 21; 23. When flow occurs against the valve discs 21; 23, the valve discs 21; 23 lift off their valve seat surface 41; 43. The lifting movement is limited by a support disc 45; 47.

[0028] In a second operating range with a piston rod speed that is greater than the limiting speed of the first operating range, i.e., greater than the exemplary 1 m / s, the valve element 29 moves into a maximum expansion position and thus into a throttle position with the minimum throttle cross-section 39, and in doing so executes a closing movement in the direction of the flow guide surface 33. Due to the high flow velocity of the damping medium in the throttle point 31, which is shaped as an annular gap, a negative pressure is formed, which leads to the radial expansion of the valve element 29. To ensure that the throttle point 31 cannot become blocked under any circumstances, the valve carrier 25 has a stop 49 on a cover plate 51 or 53 of the valve carrier 25. ( Fig. 2)

[0029] The Fig. 2 shows a detailed view of the damping valve device 1 according to Fig. 1. The enlargement shows that the annular groove 27, with an inner circumferential surface 55 of the valve element 29, annular groove side surfaces 57; 59 of the cover discs 51; 53, and an annular groove base surface 61, forms a pressure chamber 63 that is connected to the working chamber of the vibration damper 3 via at least one inflow opening 65 and one outflow opening 67. During a working movement of the vibration damper 3, the pressure chamber 63 causes a radially outwardly directed force component that expands the valve element 29 and supports the negative pressure situation prevailing in the throttle point 31. The functional designations "inflow opening" and "outflow opening" are to be interchanged accordingly if the flow to the damping valve device is opposite.

[0030] The Fig.2 further shows that the stop 49 is adjustable. The adjustable stop 49 is formed by a carrier-side edge 69. Preferably, the stop 49 is formed integrally with a cover or one of the cover discs 51; 53 of the valve carrier 25.

[0031] The stop 49 is designed to be continuously adjustable with regard to an effective diameter 71 for the valve element 29, for example by the cover disks 51 of the valve carrier 25 being designed in several parts and having at least one radial parting line 73 between the cover disk parts 51A; 51B. This allows the radial distance between the two cover disk parts 51A; 51B to be adjustable. For this purpose, the valve carrier 25, or the two cover disk parts 51A; 51B, are designed to be radially spreadable via an adjusting element 75. A tension spring 77, for example a ribbon spring, which surrounds the cover disk parts 51A; 51B, pretensions the two cover disk parts 51A, 51B against the adjusting element 75 and thus always ensures a defined position of the cover disk parts 51A; 51B to the actuating element 75 and thus for a defined effective diameter 71 of the stop 49.

[0032] The adjusting element 75 is guided within the hollow piston rod 9 of the vibration damper 3 and has an adjusting cone 79 which engages in the joint 73 between the two cover disc parts 51A; 51B.

[0033] During the adjustment of the minimum throttle cross-section, the adjusting element 75 is inserted axially into the piston rod 9 to a greater or lesser depth. Once the desired setting has been achieved, the valve carrier 25 is fixed to the piston rod 9 using a clamping nut 81. This also permanently adjusts the effective diameter 71 of the stop 49. The adjusting element 75 can then be removed again if necessary.

[0034] Optionally, the cover 51 or the cover disc parts 51A; 51B have a cover cap 83 that at least partially covers the parting line 73 between the cover disc parts 51A; 51B. The cover cap 83 is arranged on the side of the cover disc parts 51A; 51B facing away from the pressure chamber 63 and is centered on the piston rod 9. The cover disc parts 51A; 51B penetrate the piston rod 9 via through windows 85 and rest against the actuating element 75 via the force of the tension spring 77.

[0035] The cover cap 83 can be designed with at least one radial channel 87 in combination with a collecting groove 89 so that the cross-section of the outflow opening 67 is not influenced under any circumstances, e.g., by axial play of the components 51A; 51B within the annular groove 27.

[0036] Regardless of the adjustability of the effective diameter 21, the valve element 29 is positioned by a centering device 91 at a radial distance from the annular groove base surface 61 within the annular groove 27. The return spring 35 permanently biases the valve element 29 toward the centering device 91. The radial distance between the valve element 29 and the annular groove base surface 61 is adjustable by means of an adjusting device 93. Below a defined flow velocity, the valve element 29 rests against the centering device 91, resulting in the maximum throttle cross-section and consequently the lowest damping force setting. A large throttle cross-section means that a comparably moderate flow velocity is present for a given volume flow through the throttle point 31. The radial expansion force on the valve element 29 caused by a velocity-dependent underpressure is correspondingly low.

[0037] If the distance between the outer surface 37 and the flow guide surface 33 is reduced, i.e., the throttle cross-section 39 is reduced, the flow velocity increases and the reduced pressure increases at a comparable volume flow. Consequently, the expansion force acting on the valve element 29 increases. This relationship can be exploited by the adjustment device 93 to change the damping force characteristic of the damping valve device 1.

[0038] An actuator rod 95, as a component of the adjustment device 93, is guided within the piston rod 9. The actuator rod 95 can be driven manually, e.g., for a basic adjustment of the damping valve device 1, or externally powered, e.g., by means of an electromagnetic actuator. The actuator rod 95 can also extend axially outside the piston rod 9 and thus outside the vibration damper 3.

[0039] Radially movable transmission rods 97 are arranged between the valve element 29 and the actuator rod 95 as part of the adjustment device 93, the end faces 99 of which point in the direction of the valve element 29 form the actual centering 91. Two transmission rods 99 are sufficient to achieve sufficient centering of the valve element 29. The transmission rods 99 run outside the inflow and / or outflow openings 65; 67 and are guided within windows 101 of the piston rod 9. The cross-section of the transmission rods 97 is ultimately subordinate, so that the windows 101 can also be formed by simple transverse openings / bores. In the illustration, the transmission rods 97 slide along the annular groove side surface 57, although this feature is not absolutely necessary; it merely improves the axial support of the transmission rod 97.

[0040] Preferably, the actuator rod 95 performs an axial adjustment movement. In principle, however, a rotational adjustment movement would also be conceivable, for example, in conjunction with a cam profile on the actuator rod. In this exemplary embodiment, a conical connection 103 is provided between the actuator rod 95 and the transmission rods 97 to convert an axial movement of the actuator rod 95 into a radial adjustment movement of the transmission rods 97.

[0041] If both a stop adjustment and an adjustment of the centering diameter are provided in the damping valve device 1, then the actuator rod 97 is preferably guided within the actuating element 75 for the stop 49. Reference symbol 1 damping valve device 3 vibration dampers 5 first damping valve 7 Damping valve body 9 Piston rod 11 cylinders 13 piston rod side working space 15 working area remote from the piston rod 17 passage channels 19 passage channels 21 Valve disc 23 Valve disc 25 valve carriers 27 Ring groove 29 Valve element 29A Leg of the valve element 29B Leg of the valve element 31 throttle point 33 Flow guide surface 35 Return spring 37 outer surface of the valve element 39 Throttle cross-section of the throttle point 41 Valve seat surface 43 Valve seat surface 45 support disc 47 Support disc 49 stop 51 Cover disc 53 Cover disc 55 inner surface of the valve element 57 Ring groove side surface 59 Ring groove side surface 61 Ring groove base area 63 Printing room 65 Inlet opening 67 Outlet opening 69 rand 71 effective diameter 73 Separation joint 75 Control element 77 tension spring 79 Adjusting cone 81 clamping nut 83 Cover cap 85 passage windows 87 Radial canal 89 collecting groove 91 Centering 93 Adjustment device 95 Actuator rod 97 transmission rods 99 frontal area 101 windows 103 Cone connection

Claims

[1] Damping valve device (1) for a vibration damper (3), comprising a throttle point (31) in conjunction with a valve element (29) which can be transferred from a passage position into a throttle position depending on the flow velocity of a damping medium within the throttle point (31), wherein the valve element (29) is arranged as a ring element whose diameter can be changed within an annular groove (27) of a valve carrier (25), wherein the valve element (29) and the annular groove (27) form a pressure chamber (63) with mutually facing lateral surfaces (55; 61), wherein the valve element (29) is positioned by a centering device (91) at a radial distance from an annular groove base surface (61) of the annular groove (27), and the distance can be adjusted by means of an adjusting device (93), characterized bythat the damping valve device (1) is arranged on a piston rod (9) of the vibration damper (3) and an actuator rod (95) of the adjusting device (93) is guided within the piston rod (9) and radially movable transmission rods (97) are arranged between the valve element (29) and the actuator rod (95), the end faces (99) of which point in the direction of the valve element (29) form the centering (91). [2] Damping valve device according to claim 1, characterized by that the transmission rods (97) are guided within windows (101) of the piston rod (9). [3] Damping valve device according to claim 1, characterized by that there is a conical connection (103) between the actuator rod (95) and the transmission rods (97). [4] Damping valve device according to one of claims 1-3, characterized bythat a maximum throttle position of the valve element (29) is determined by a support-side stop (49), the effective diameter (71) of which is adjustable for the valve element (29). [5] Damping valve device according to claim 4, characterized by that the stop (49) is adjustable by means of an adjusting element (75). [6] Damping valve device according to one of claims 4 or 5, characterized by that a cover disc (51) of the valve carrier (25) forming the stop (49) is designed in several parts and has at least one radial parting line (73) between the cover disc parts (51A; 51B). [7] Damping valve device according to claim 6, characterized by that the cover disc (51) has a cover cap (83) which at least partially covers the parting line (71). [8] Damping valve device according to one of claims 5-7, characterized by that the actuator rod (95) is guided within the actuating element (75) for the stop (49).

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