Damping valve device

Abstract

Damping valve device (1), comprising a valve carrier (25) with a circumferential annular groove (27) in which a valve element (29) of variable diameter is arranged, which changes from a flow position to a throttle position depending on the flow velocity between the valve element (29) and a flow guide surface (33) of a damping medium, wherein a jacket surface (55) of the valve element (29) and the annular groove (27) delimit a pressure chamber (57) which has at least one inflow opening (59) and at least one outflow opening (61), wherein the pressure within the pressure chamber (57) exerts a radial adjusting force on the valve element (29), wherein within the pressure chamber (57; 57a; 57B) for the valve element (29) there is a pressure-dependent damping valve (53; 53A; 53B), wherein the valve element (29) is designed for a valve disc (63) of the pressure-dependent damping valve (53; 53A;53B) has a valve seat surface (75) and the valve seat surface (75) is formed by an annular profile (77) of the valve element (29), characterized in that the valve seat surface (75) has a partial section whose level position lies below a bottom side (81) of the valve disc (63) in the relaxed operating state of the valve disc (63) of the pressure-dependent damping valve (53; 53A; 53B).

Description

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

[0002] DE 10 2019 212 966 A1 discloses a damping valve device in which an annular valve element performs a radial expansion movement, so that a throttle cross-section formed by the valve element and a flow guide surface transitions from a maximum open position to a throttle position. In addition, the damping valve device comprises a pressure relief valve connected to a pressure chamber defined by a circumferential surface of the valve element, so that the circumferential surface represents a pressurized surface, via which a radial actuating force is exerted on the valve element depending on the pressure level within the pressure chamber.

[0003] An advantage of the pressure relief valve is that the damping valve device and thus the entire vibration damper is protected from overload, e.g. due to a blocking position of the valve element.

[0004] From the older DE 10 2021 213 455 A1, a damping valve device is known whose annular valve element is connected to a pressure chamber, the inlet of which is equipped with a frequency-selective valve located outside the pressure chamber. This is intended to hydraulically filter out, or at least attenuate, high-frequency excitations to the pressure chamber and thus to the valve element.

[0005] DE 10 2020 209 110 A1 discloses a generic damping valve device with a pressure-dependent damping valve within said pressure chamber that controls the inflow into the pressure chamber. The annular valve element, with its circular cover, has a valve seat surface for a valve disc of the pressure-dependent damping valve.

[0006] DE 10 2020 209 102 A1 also relates to a damping valve device with an annular valve element that assumes a throttle position relative to a flow guide surface depending on the speed. Valve elements are arranged outside a valve carrier to adjust the damping force characteristics of the damping valve device.

[0007] In DE 10 2021 201 425 A1, the damping valve device has an axially movable, additional valve body within a pressure chamber for the annular valve element, which alternately determines the cross-section of an outflow opening.

[0008] The object of the present invention is to improve the damping valve device so that an even more individual adjustment of the damping force characteristics is possible.

[0009] The problem is solved by the features of patent claim 1.

[0010] The pressure-dependent damping valve ensures a gentle start to the expansion movement of the annular valve element. This reliably prevents impact noises from the valve element within the annular groove. The arrangement of the pressure-dependent damping valve within the pressure chamber results in a particularly compact design.

[0011] This design offers the option of changing the pressure-actuated area of ​​the pressure-dependent damping valve in the opening direction depending on the throttle position of the valve element. This implements an additional progression in the damping force characteristic.

[0012] Due to the design of the valve seat surface on the valve element, the initial position of the valve element is reliably maintained with minimal flow to the damping valve device. The valve seat surface can thus always slide under the valve disc of the pressure-dependent damping valve.

[0013] In a further advantageous embodiment, the outflow opening is equipped with a pressure relief valve that opens in the outflow direction from the pressure chamber and is hydraulically arranged in series with the pressure-dependent damping valve in the inflow direction. The two damping valves in the pressure chamber enable the damping valve device to be specifically tuned to a specific damping force behavior, on the one hand, and to suppress any noise, on the other.

[0014] In a further advantageous embodiment of the invention, the pressure-dependent damping valve of the inflow direction is centered on an annular groove base surface of the annular groove.

[0015] Another option is for the valve seat surface of the pressure-dependent damping valve to divide the valve element's outer surface facing the pressure chamber into a first and a second partial area. For this purpose, for example, the valve seat surface on the valve element can be arranged at a distance from a side surface of the annular groove of the valve carrier. Dividing the pressure chamber into two also achieves a delayed operating movement of the valve element.

[0016] It is also possible to provide for a first pressure-dependent damping valve to open a first portion of the pressure chamber, and a second pressure-dependent damping valve to open a second portion of the pressure chamber. This arrangement of the pressure-dependent damping valves allows the damping force behavior of the damping valve device to be determined even more precisely.

[0017] In order to ensure a simple overall design of the damping valve device, the two pressure-dependent damping valves are hydraulically connected in series with respect to the discharge opening of the pressure chamber.

[0018] The invention will be explained in more detail with reference to the following description of the figures.

[0019] It shows: Fig. 1 Installation situation of the damping valve device in a vibration damper Fig. 2 Damping valve device as an assembly according to Fig. 1 Fig. 3 Qualitative damping force characteristic curve of the damping valve device according to Fig. 2 Fig. 4 - 7 Further embodiments of a damping valve device

[0020] 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.

[0021] The damping valve body 7 divides a cylinder 11 of the vibration damper 3 into a working chamber 13; 15 on the piston rod side and a working chamber 13; 15 remote from the piston rod, 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.

[0022] For example, a valve carrier 25 of the damping valve device 1 is fixed directly to the piston rod 9.

[0023] The valve carrier 25 has a circumferential annular groove 27 in which an annular valve element 29 with variable diameter is guided. 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. For example, the valve element can be designed as a radially elastic component. Alternatively, it is also possible for the valve element to have, for example, articulated legs that execute a radial pivoting movement. With regard to an articulated mounting, reference is made to DE 10 2019 215 558 A1 as an example. The valve element 29 forms the throttle point 31 with an inner wall of the cylinder 11, wherein the inner wall represents a flow guide surface 33.

[0024] 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.

[0025] 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.

[0026] 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 transitions to a throttle position and performs 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 created, which leads to a radial expansion of the valve element 29. To prevent the throttle point 31 from becoming blocked under any circumstances, the defined minimum flow cross-section can be maintained, for example, by the return spring 35. In the present embodiment, the valve carrier 25 has a stop 49 for this purpose, and a cover side of the valve element 25 has a counter-stop 51. ( Fig. 2)

[0027] Furthermore, the damping valve device 1 comprises at least one pressure-dependent damping valve 53 for controlling the operating behavior of the valve element 29. In the Fig. This is discussed in detail in sections 2 ff.

[0028] The Fig. Figure 2 shows the damping valve device 1 on a larger scale. In this Fig. 2 it can be seen that an inner circumferential surface 55 of the valve element 29 and the annular groove 27 of the valve carrier 25 delimit a pressure chamber 57 which is connected to the adjacent working chamber 13 via at least one inflow opening 59 and at least one outflow opening 61. The pressure within the pressure chamber 57 exerts a radial adjusting force on the valve element 29 and thus supports the expansion force effective due to the reduced pressure prevailing in the throttle point 31. Both pressure force components act in the same direction and have a greater effect with increasing flow velocity of the damping medium. When the throttle point 31 is effective, the working chamber on the piston rod side is divided into a partial working chamber between a piston rod guide and the valve carrier and a partial working chamber between the valve carrier and the piston 7.

[0029] The cross-section of the inlet opening 59 tends to be larger than the cross-section of the outlet opening 61. The ratio of these two cross-sections to each other can be used to adjust the basic operating behavior of the valve element 29. The larger the cross-section ratio, the lower the flow velocity during a triggering movement of the valve element 29.

[0030] Furthermore, the Fig. 2 that a pressure-dependent damping valve 53, which controls the inflow direction into the pressure chamber 57 for the valve element 29, is arranged within the pressure chamber 57. The pressure-dependent damping valve 53 comprises at least one valve disc 63, which rests on a valve seat surface 65 and is centered on an annular groove base surface 67 of the annular groove 27. A stop 68, for example in the form of a retaining ring, holds the valve disc 63 within the annular groove 27. In this exemplary embodiment, the valve seat surface 65 is formed by an annular groove side surface of the annular groove 27. The at least one valve disc 63 is designed to be elastic here. However, it can also be provided that a closing spring, if necessary, also preloads a rigid valve disc 63 onto the valve seat surface 65.

[0031] Optionally, the outflow opening 61 is also equipped with a pressure relief valve 69 opening in the outflow direction from the pressure chamber 57, which is hydraulically arranged in series with the pressure-dependent damping valve 53 in the inflow direction into the pressure chamber 57. The structural design of the pressure relief valve 69 is only an example.

[0032] The Fig. 3 shows the qualitative damping force curve of the damping valve device 1 according to Fig. 2. Starting from a stationary state of the vibration damper 3, in which no displacement of damping medium between the working chambers and thus no damping force occurs, see point P0, at low working speeds of the vibration damper 3 between the two points P0 and P1 the damping force level which is set by the maximum passage position of the valve element 29 acts, which is comparatively low.

[0033] From operating point P1, the flow velocity within the throttle point 31 is so great that a reduced pressure within the throttle point 31 causes an expansion force on the valve element 29, so that the throttle cross-section 39 of the throttle point 31 decreases and thus the damping force increases. In the exemplary embodiment, the pressure-dependent damping valve in the pressure chamber opens from operating point P2, whereby the throttle cross-section 39 of the throttle point 31 further decreases and the damping force increases. The gradient depends on the ratio of the outflow cross-section 61 to the inflow cross-section 59. From point P3, the optional pressure relief valve 69 of the pressure chamber 57 opens, so that the further increase in the damping force is significantly more moderate.

[0034] The damping valve device according to the Fig. 4 is based on the principle according to the Fig. 2. In addition, the valve element for the valve disc 63 of the pressure-dependent damping valve 53 has a stop surface 71 in the lift direction. In the initial position of the annular valve element 29, i.e. at the maximum flow cross-section 33 of the throttle point 31, there is a radial overlap between the valve disc 63 and the stop surface 71 of the valve element 29. This overlap can be partial, since the valve disc 63 rests on the valve seat surface 65 of the annular groove side surface and a desired minimum flow cross-section on the damping valve 53, if desired, is determined between these two components. At an increased pressure within the inlet opening 59, the lift force would be sufficient for a lift movement of the valve disc 63. However, the lift movement of the valve disc 63 is limited by the stop surface 71 on the valve element 29 or, if necessary, blocked.Only when the valve element 29 has completed a certain expansion movement in the direction of the flow guide surface 33 does the stop surface 71 release the pressurized damping valve 53. This tends to shift the operating point P2 toward the operating point P3, which remains unchanged at the discharge opening 61 with an otherwise identical design of the pressure relief valve 6. A positive side effect is that the lifting movement of the valve disc 63 leads to a pressing force on the valve element 29 in the direction of an annular groove side surface 73 opposite the valve disc 63. This at least reduces impact noises caused by an axial force component when the valve element is flowing against it.

[0035] The inventive design of the damping valve device 1 according to Fig. 5 is characterized in that the valve element 29 of the throttle point 31 for the valve disc 63 of the pressure-dependent damping valve 53 has a valve seat surface 75. The valve seat surface 75 is preferably formed by an annular profile 77 of the valve element 29, which extends as a flange from the inner circumferential surface 55 of the valve element 29 in the direction of the annular groove base surface 67. The valve seat surface 75 on the annular profile 77 is oriented in the direction of the outflow opening 61. A partial region of the annular groove side surface forms an axial support surface 79 on the inner diameter region of the at least one valve disc 63 of the pressure-dependent damping valve 53. Alternatively, a simple support sleeve can also be used between the annular groove side surface and the first valve disc 63.

[0036] Preferably, the valve seat surface 75 has a partial section whose level lies below a bottom side 81 of the valve disc 63 in the relaxed operating state of the valve disc 63 of the pressure-dependent damping valve 53. In this exemplary embodiment, the valve seat surface 75 is designed to slope conically toward the annular groove base surface 67.

[0037] When the annular valve element 29 expands, the pressurized surface on the valve disc 63 resting on the valve seat surface 75 increases. Due to the conical, sloping valve seat surface 75 on the valve element 29, the preload on the valve disc 63 or the valve discs is reduced. Consequently, the necessary opening pressure on the pressure-dependent damping valve 53 decreases the closer the valve element 29 approaches the flow guide surface 33 or the smaller the throttle cross-section 39 of the throttle point 31 is. Due to this characteristic of the damping valve device 1, the operating point P2 tends to shift in the direction of the operating point P1, with otherwise identical dimensions of the components of the damping valve device 1. The conical valve seat surface 75 in conjunction with the return spring 35 leads to a reliable return of the valve element 29 to the intended starting position of the valve element 29, i.e.that the valve disc 63 of the pressure-dependent damping valve 53 can slide back onto the valve seat surface 75.

[0038] The second embodiment of the damping valve device 1 according to the invention Fig. 6 is based on the design according to Fig. 5. In contrast, the valve seat surface 75 of the pressure-dependent damping valve 53 divides the outer surface 55 of the valve element 29 facing the pressure chamber 57 into a first and a second partial area 55A; 55B and thus the pressure chamber 57 into a first and a second partial area 57A; 57B. In comparison to the function according to Fig. 5, a first unthrottled or slightly throttled partial area 57A between the inlet opening 59 and the valve seat surface 75 on the valve element 29 is available for an operating movement of the valve element 29. This first partial area of ​​the pressure chamber 57A or the jacket surface 55A is thus available even with the slightest flow into the pressure chamber 57. The second partial area 57B of the pressure chamber 57 only takes effect after the pressure-dependent damping valve 53B has opened. If one uses an identical valve design as in Fig. 5, then the operating point P2 tends to shift towards the operating point P1.

[0039] With the design of the damping valve device 1 according to Fig. 7 appears in comparison to the execution after Fig. 6 an opposite effect is achieved. After opening a first pressure-dependent damping valve 53A, only the first partial area 57A of the pressure chamber 57 is released. Even during an expansion movement of the annular valve element 29, a valve disc 63B of a second pressure-dependent damping valve 53B still rests on a valve seat surface 75 of the valve element 29. This valve seat surface 75 can, for example, correspond to the design of the valve seat surface 75 according to the Fig. 6. Only when the second pressure-dependent damping valve 53B lifts off the valve seat surface 75, the second partial area 57B of the pressure chamber 57 is released, which causes a further force component on the valve element 29 in the direction of the flow guide surface 33. A greater opening force is necessary for the second damping valve 53B than for the first damping valve 63A. The second damping valve 53B thus divides the annular groove 27 into two pressure chambers 57A; 57B, which are arranged axially in series, so that the two pressure-dependent damping valves 53A; 53B are also hydraulically connected in series with respect to the outflow opening 61 of the pressure chamber 57. As a result, the operating point P2 with respect to the illustration according to Fig. 3 shifted towards the operating point P3.

[0040] The variant of the damping valve device according to the invention Fig. 7 can also be connected to the damping valve 53 of the damping valve device according to Fig. 4. A combination of the damping valve 53 according to the Fig. 5 in the function of the damping valve 53A according to the Fig. 7 may be useful. In addition, in the execution according to Fig. 7 the discharge opening 61 must be equipped with a pressure relief valve 69. 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 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 Counter stop 53 Damping valve 53A Damping valve 53B Damping valve 55 lateral surface 55A Partial area of ​​the lateral surface 55B Partial area of ​​the lateral surface 57 Printing room 57A first part of the pressure chamber 57B second part of the pressure chamber 59 Inlet opening 61 Outlet opening 63 Valve disc of the damping valve 53 65 valve seat surface 67 Ring groove base area 68 tee 69 Pressure relief valve 71 Stop surface 73 Ring groove side surface 75 valve seat surface 77 Ring profile 79 Support surface 81 subpage

Claims

[1] Damping valve device (1), comprising a valve carrier (25) with a circumferential annular groove (27) in which a valve element (29) of variable diameter is arranged, which changes from a through position to a throttle position depending on the flow velocity between the valve element (29) and a flow guide surface (33) of a damping medium, wherein a jacket surface (55) of the valve element (29) and the annular groove (27) delimit a pressure chamber (57) which has at least one inflow opening (59) and at least one outflow opening (61), wherein the pressure within the pressure chamber (57) exerts a radial adjusting force on the valve element (29), wherein within the pressure chamber (57; 57a; 57B) for the valve element (29) a pressure-dependent damping valve controlling the inflow into the pressure chamber (57; 57A; 57B) (53; 53A; 53B), wherein the valve element (29) is designed for a valve disc (63) of the pressure-dependent damping valve (53; 53A;53B) has a valve seat surface (75) and the valve seat surface (75) is formed by an annular profile (77) of the valve element (29); characterized by that the valve seat surface (75) has a partial section whose level position lies below a bottom side (81) of the valve disc (63) in the relaxed operating state of the valve disc (63) of the pressure-dependent damping valve (53; 53A; 53B). [2] Damping valve device (1) according to claim 1, characterized by that the outflow opening (61) is equipped with a pressure relief valve (69) opening in the outflow direction from the pressure chamber (57; 57B), which is hydraulically arranged in series with the pressure-dependent damping valve (53; 53A; 53B) of the inflow direction. [3] Damping valve device (1) according to at least one of claims 1 or 2, characterized by that the pressure-dependent damping valve (53; 53A; 53B) of the inflow direction is centered on an annular groove base surface (67) of the annular groove (27). [4] Damping valve device (1) according to claim 1, characterized by that the valve seat surface (75) of the pressure-dependent damping valve (53; 53B) divides a jacket surface (55) of the valve element (29) facing the pressure chamber (57) into a first and a second partial region (55A; 55B). [5] Damping valve device (1) according to claim 4, characterized by that a first pressure-dependent opening damping valve (53A) releases a first partial area (57A) of the pressure chamber (57) and a second pressure-dependent damping valve (53B) releases a second partial area (57B) of the pressure chamber (57). [6] Damping valve device according to claim 5, characterized by that the two pressure-dependent damping valves (53A; 53B) are hydraulically connected in series with respect to the outflow opening (61) of the pressure chamber (57; 57B).

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