Adjustable damping valve device with an emergency operating function for a vibration damper

Abstract

Adjustable damping valve device comprising an actuator with a solenoid coil and a valve armature, wherein the valve armature is slidably mounted in a sleeve-shaped return body, wherein the return body has a bottom-side pole disk which is fixedly arranged to a valve housing, wherein an emergency operating valve body switches between an emergency operating position and a normal operating position depending on the power supply to the solenoid coil, wherein the emergency operating valve body is switched by the force of the magnetic flux of the solenoid coil through the return body and the pole disk, wherein a magnetic flux resistance is arranged between the pole disk and the valve housing, wherein the magnetic flux resistance is formed by a reduction in the wall thickness of the return body.

Description

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

[0002] DE 10 2015 200 348 A1 relates to a generic damping valve device with an emergency operating element that moves from an emergency operating position to a normal operating position depending on the power supply to a solenoid coil. When the onboard electrical system is switched on, the damping valve device is supplied with a threshold current, which, in conjunction with the solenoid coil, provides a lifting force that, in turn, holds the emergency operating element in the normal position. If this power supply fails, the emergency operating element is moved to the emergency operating valve position, causing the damping valve device to generate a damping force that does not necessarily correspond to a maximum damping force characteristic.

[0003] An actuator comprising the solenoid coil further includes a sleeve-shaped return body in which a valve armature is slidably mounted. The return body comprises an annular body through which the valve armature is axially penetrated and which supports it. The annular body is fixed in a magnetically non-conductive sleeve section of the return body. This non-conductive sleeve section, acting as a magnetic flux resistor, is supported axially and radially by a valve housing section of the damping valve assembly. This valve housing section is part of the magnetic flux circuit of the solenoid coil.

[0004] Both the valve armature and the emergency operating valve body are integrated into the same magnetic flux circuit of the solenoid coil.

[0005] The object of the present invention is to improve the response behavior of the emergency operating valve body to a threshold current of the solenoid coil and to simplify the design of the damping valve device.

[0006] The problem is solved by creating a magnetic flux resistance that is achieved by reducing the wall thickness of the return body.

[0007] A significant advantage is that the sleeve-shaped section of the return body is no longer made up of multiple parts.

[0008] In a further advantageous embodiment of the invention, the reduction in wall thickness is achieved by increasing the inner diameter of the return body.

[0009] Furthermore, the first reduction in wall thickness is formed by an inner step of the return body, against which the pole disk is axially supported.

[0010] The reduction in wall thickness of the return element is limited to the axial extent of a contact surface between the pole disk and the return element. This results in a compact arrangement of the pole disk within the return element, combined with a simple component geometry for the return element.

[0011] Furthermore, the valve housing has an axial support surface for the solenoid coil, with the wall thickness reduction extending axially from this support surface. This measure also serves to simplify the implementation of the wall thickness reduction.

[0012] Preferably, the return element and the valve housing are manufactured seamlessly as a single piece. This measure reduces the manufacturing effort of the damping valve assembly.

[0013] Optionally, the backplate has a second magnetic flux resistance connected in parallel to a magnetic flux path from the backplate to the valve armature. This magnetic flux resistance is also formed by a reduction in the wall thickness of the backplate.

[0014] The two magnetic flux resistors can be dimensioned independently of each other with respect to their resistance function.

[0015] The following description of the figures will be used to explain the invention in more detail.

[0016] It shows: Fig. 1 Installation situation of the damping valve device on a vibration damper Fig. 2 Sectional view through the damping valve assembly.

[0017] In Fig. A vibration damper comprises a cylinder 1 in which a piston rod 3 is axially movable. A guide and sealing unit 7 extends the piston rod 3 from the upper end of the cylinder. Inside the cylinder 1, a piston assembly 9 with a piston valve assembly 11 is attached to the piston rod 3. The lower end of the cylinder 1 is closed by a base plate 13 with a base valve assembly 15. The cylinder 1 is enclosed by a reservoir tube 17. The reservoir tube 17 and an intermediate tube 5 form an annular space 19, which constitutes a compensating chamber. The space inside the cylinder 1 is divided by the piston assembly 9 into a first working chamber 21a and a second working chamber 21b. The working chambers 21a and 21b are filled with damping fluid. The compensating chamber 19 is filled with fluid up to the level 19a and with gas above that level.Within the compensation chamber 19, a first line section, namely a high-pressure section 23, is formed, which is connected to the second working chamber 21b via a bore 25 of the cylinder 1. An adjustable damping valve assembly 27, mounted laterally on the reservoir tube 17, is connected to this high-pressure section. A second line section leads from this (see figure 23). Fig. 2), namely a low-pressure section 29, into the equalization chamber 19.

[0018] When the piston rod 3 extends upwards from the cylinder 1, the upper working chamber 21b shrinks. An overpressure builds up in the upper working chamber 21b, which can only be released into the lower working chamber 21a via the piston valve assembly 11 as long as the adjustable damping valve assembly 27 is closed. When the adjustable damping valve assembly 27 is open, fluid simultaneously flows from the upper working chamber 21b through the high-pressure section 23 and the adjustable damping valve assembly 27 into the compensation chamber 19. The damping characteristic of the vibration damper during the extension of the piston rod 3 therefore depends on whether the adjustable damping valve assembly 27 is more or less open or closed.

[0019] When the piston rod 3 retracts into the cylinder 1, an overpressure builds up in the lower working chamber 21a. Fluid can flow from the lower working chamber 21a upwards through the piston valve assembly 11 into the upper working chamber 21b. The fluid displaced by the increasing piston rod volume within the cylinder 1 is expelled through the bottom valve assembly 15 into the compensation chamber 19. Since the flow resistance of the piston valve assembly 11 is lower than that of the bottom valve assembly 15, an increasing pressure also occurs in the upper working chamber 21b. With the damping valve assembly 27 open, this increasing pressure can again flow through the high-pressure section 23 into the compensation chamber 19.This means that with the damping valve assembly 27 open, the vibration damper has a softer characteristic when retracting if the adjustable damping valve assembly 27 is open, and a firmer characteristic when the damping valve assembly 27 is closed, just as when the piston rod is extending. It should be noted that the flow direction through the high-pressure section 23 of the bypass is always the same, regardless of whether the piston rod is retracting or extending.

[0020] The adjustable damping valve assembly 27 is located in the Fig. Figure 2 shows a cross-sectional view. In principle, the invention can also be used with a damping valve device 27 on the piston rod 3.

[0021] The damping valve assembly 27 comprises an actuator 31 with a solenoid coil 33 for controlling a valve armature 35, which is at least indirectly connected to a pre-stage valve 37, which in turn determines a closing force on a main stage valve 39. The main stage valve 39 has a main stage valve body 41, the rear side of which forms a valve seat surface 43 for a pre-stage valve body 45.

[0022] Furthermore, the damping valve assembly 27 has an emergency operating function based on the position of an emergency operating body 47, which is biased by a spring 48 in the direction of the pre-stage valve body 45.

[0023] The valve armature 35 is slidably mounted in a sleeve-shaped return body 49, the return body 49 having a bottom-side pole disk 51 that is fixedly arranged relative to a valve housing 53. In this embodiment, the valve armature 35 is mounted in the pole disk 51 and in a cover area 61 of the return body 49 via a central armature rod 55 with intermediate bearing sleeves 57; 59.

[0024] The emergency operating body 47 switches between an emergency operating position and a normal operating position depending on the power supply to the magnetic coil 33, whereby the emergency operating body 47 is switched by the force of the magnetic flux of the magnetic coil 33 through the backstop body 49 and the pole disk 51.

[0025] A magnetic flux resistor is arranged between the pole disk 51 and the valve housing 53, preventing a magnetic flux short circuit with respect to the pole disk 51. The magnetic flux resistor ensures that the magnetic flux is conducted from the pole disk 51 to the emergency operating element 47, thereby achieving the greatest possible tensile force on the emergency operating element 47 relative to the set current for the solenoid coil 35. This tensile force holds the emergency operating element 47 in the normal operating position against the force of the spring 48 when a threshold current for the solenoid coil is exceeded. In the emergency operating position, the emergency operating element 47 rests against the rear of the pre-stage valve body 45. The spring 48 then indirectly transmits a closing force to the pre-stage valve body 45.In the normal operating position of the emergency operating element 47, there is a gap between the emergency operating element 47 and the pre-stage valve body 45, irrespective of the operating position of the pre-stage valve body 45. It can be provided that the emergency operating element 47 rests against the pole disk 51 in the normal operating position.

[0026] How to Fig. 2 can be seen, the magnetic flux resistance is formed by a reduction in wall thickness 63 by an increase in the inner diameter of the return body 49.

[0027] The back end body 49 has a multi-stage internal profile, in which the wall thickness reduction 63 is formed by an internal shoulder 65 of the back end body 49, on which the pole disk 51 is also axially supported.

[0028] The reduction in wall thickness 63 of the return body 49 is axially limited to a minimal length, namely essentially to the axial extent of a contact surface 67 of the pole disk 51 with the return body 49. The contact surface 67 also serves as a pressing surface for a force-fit connection to the valve housing 53. The reduction in wall thickness 63 also promotes the radial expansion capability of the return body 49 to accommodate the pole disk 51.

[0029] The valve housing 53 has an axial support surface 69 for the solenoid coil 33, with the wall thickness reduction 63 extending axially from this support surface 69 towards the cover area 61 of the return body 49. Thus, the area with the wall thickness reduction 63 is located entirely within an internal area bounded by the solenoid coil 33. An area of ​​the valve housing 53 located below the solenoid coil 33 can be used and optimized for other functions.

[0030] In principle, the return element 49 and the valve housing 53 could be manufactured as two parts and then joined together. Preferably, the return element 49 and the valve housing 53 are manufactured seamlessly as a single piece. This one-piece construction avoids manufacturing tolerances that would result from a two-part design.

[0031] Optionally, the backstop body 49 has a second magnetic flux resistor 71 within the sleeve-shaped section, which is connected in parallel to a magnetic flux path from the backstop body 49 to the valve armature 35. The second magnetic flux resistor 71 is also formed by a reduction in wall thickness, but this reduction is formed by an outer circumferential groove. Starting from the radially deepest region of the groove, or the thinnest wall thickness, the wall thickness of the backstop body 49 increases towards the pole disk 51. The pole disk 51 also rests directly against the shoulder of the backstop body 49. Consequently, the area from the second reduction in wall thickness 71 to the top surface of the pole disk 51 forms a step for the valve armature. The pole disk 51 can be designed as a flat disk in the direction of the valve armature 35.

[0032] When the solenoid coil 33 is energized, a closed magnetic flux path exists around the solenoid coil 33. A valve housing cover 73 is a component that conducts the magnetic flux very well and has direct contact with the return element 49 in the area of ​​a through-opening 75 in a base 77. The magnetic flux enters the return element 49 at this point. Further along the path up to the second wall thickness reduction 71, the return element 47 has a wall cross-section optimized for radial transmission of the magnetic flux to the valve armature 35. Due to the second magnetic flux resistance 71, the magnetic flux passes through the valve armature 35 and then, in the direction of the pole disk 51, returns to the return element 49, which then, together with the pole disk, forms a plunge profile for the valve armature 35.With increasing current and as the valve armature 35 approaches the pole disk 51, there is a greater axial overlap with the return element 49 in the area between the second and the first magnetic flux resistance 71; 63. Furthermore, with increasing overlap, there is a larger conductor cross-section at the return element 49 in the direction of the pole disk 51. With sufficient approach, the magnetic flux passes directly from the valve armature 35 into the pole disk 51.

[0033] The emergency operating element 47 has a blind opening 79 facing the pole disk 51, which, together with a projecting shoulder 81 of the pole disk 51, also forms a plunge profile and has a small axial overlap. When the solenoid coil 33 is energized, a tensile force can be exerted on the emergency operating element 47, whereby a circumferential surface 81 of the emergency operating element 47 allows the magnetic flux to pass into the valve housing 53 in order to close the magnetic flux of the solenoid coil 33. Reference sign 1 cylinder 3 Piston rod 5 Intermediate pipe 7 Guide and sealing unit 9 piston unit 11 Piston valve arrangement 13 Base plate 15 Bottom valve arrangement 17 Container pipe 19 Ring space 21a / b Chamber of Labour 23 High-pressure section 25 bore 27 Damping valve device 29 Low-pressure section 31 Actuator 33 Magnetic coil 35 Valve anchors 37 Pre-stage valve 39 Main stage valve 41 Main stage valve bodies 43 Valve seat surface 45 Pre-stage valve bodies 47 emergency power units 48 springs 49 Return body 51 Polarizing disc 53 Valve housings 55 Anchor rod 57 Bearing sleeve 59 Bearing sleeve 61 Cover area 63 Wall thickness reduction 65 paragraph 67 Contact area 69 support surface 71 second magnetic flux resistance 73 Valve housing cover 75 Passage opening 77 Floor 79 Blind hole opening Paragraph 81 83 Surface area QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2015 200 348 A1

[0002]

Claims

[1] Adjustable damping valve device (27) comprising an actuator (31) with a solenoid coil (33) and a valve armature (35), wherein the valve armature (35) is slidably mounted in a sleeve-shaped return body (49), wherein the return body (49) has a bottom-side pole disk (51) which is fixedly arranged to a valve housing (53), wherein an emergency operating element (47) switches between an emergency operating position and a normal operating position depending on the power supply to the solenoid coil (33), wherein the emergency operating element (47) is switched by the force of the magnetic flux of the solenoid coil (33) through the return body (47) and the pole disk (51), wherein a magnetic flux resistor is arranged between the pole disk (51) and the valve housing (53), characterized by , that the magnetic flux resistance is formed by a reduction in wall thickness (63) of the return body (49). [2] Adjustable damping valve device (27) according to claim 1, characterized by , that the first wall thickness reduction (63) is formed by an increase in the inner diameter of the return body (49). [3] Adjustable damping valve device (27) according to claim 2, characterized by , that the first wall thickness reduction (63) is formed by an inner shoulder (65) of the return body (49) on which the pole disk (51) is axially supported. [4] Adjustable damping valve device (27) according to claim 2 or 3, characterized by , that the wall thickness reduction (63) of the return body (49) is essentially limited to the axial extension of a contact surface (67) of the pole disk (51) with the return body (49). [5] Adjustable damping valve device (27) according to any one of claims 1 to 4, characterized by , that the valve housing (53) has an axial support surface (69) for the solenoid coil (33), wherein the wall thickness reduction (63) extends axially from this support surface (69). [6] Adjustable damping valve device (27) according to any one of claims 1 to 5, characterized by , that the return body (49) and the valve housing (53) are seamlessly manufactured as a single piece. [7] Adjustable damping valve device (27) according to any one of claims 1 to 6, characterized by , that the backflow body (49) has a second magnetic flux resistance (71) which is connected in parallel to a magnetic flux path from the backflow body (49) to the valve armature (35).

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