Adjustable damping valve device with emergency operation valve for shock absorber

Abstract

The invention relates to an adjustable damping valve device, comprising an actuator with an excitation coil and a valve armature, wherein the valve armature is movably supported in a sleeve-like yoke body, wherein the yoke body has a pole disc on the bottom side, which is arranged position-fixed relative to the valve housing, wherein an emergency operation valve body is switched between an emergency operation state and a normal operation state depending on the power supply of the excitation coil, wherein the emergency operation valve body is switched by a force caused by the magnetic flux of the excitation coil through the yoke body and the pole disc, wherein a magnetic resistance is arranged between the pole disc and the valve housing, wherein the magnetic resistance is generated by an additional magnetic field outside the magnetic field of the excitation coil.

Description

Technical Field

[0001] The present invention relates to an adjustable damping valve device having an emergency operation valve as described in the preamble of claim 1. Background Technology

[0002] Document DE 10 2015 200 348 A1 relates to a general type of damping valve device having an emergency operating valve body that moves from an emergency operating position to a normal operating position depending on the power supply to the excitation coil. When the vehicle electronics are powered on, a threshold current is applied to the damping valve device, which, in conjunction with the excitation coil, generates a lifting force that holds the emergency operating valve body in the normal position. If the power supply is interrupted, the emergency operating valve body moves to the emergency operating position, causing the damping valve device to generate a damping force, which does not necessarily correspond to the stiffest damping force characteristic.

[0003] The actuator with an excitation coil also includes a sleeve-shaped yoke in which a valve armature is slidably supported. The yoke includes an annular body through which the valve armature passes axially and supports the armature. This annular body is fixed within a non-magnetic sleeve section of the yoke. This non-magnetic sleeve section acts as a magnetic reluctance, supporting the valve body section of the damping valve assembly axially and radially. This valve body section is part of the magnetic flux loop of the excitation coil.

[0004] The valve armature and the valve body of the emergency operation valve are located in the same magnetic flux circuit of the excitation coil. Summary of the Invention

[0005] The purpose of this invention is to improve the response behavior of the emergency operation valve body to the threshold current of the excitation coil and to simplify the structural design of the damping valve device.

[0006] The means to achieve this is to provide a circumferential side region with increased magnetic resistance for the valve body of the emergency operation valve.

[0007] This allows for a significant increase in the holding force acting on the valve body of the emergency operation valve without the need for, for example, a more powerful excitation coil or a higher drive current.

[0008] Preferably, the circumferential side region is formed by a shoulder that forms an air gap with the adjacent flux-conducting member. This shoulder is easy to manufacture; in particular, it is advantageous to use a sintering process to manufacture the emergency operation valve body.

[0009] To prevent the emergency operation valve body from tilting when switching between the emergency operation position and the normal position, the shoulder is divided into multiple individual notches by multiple guide elements configured as guide bars.

[0010] To facilitate the use of readily available original molding techniques for the emergency operation valve body, the notch is open on the end side.

[0011] Alternatively or in combination, a guide element configured as a guide protrusion is arranged in the shoulder.

[0012] The circumferential side region can also be formed by at least one surrounding groove.

[0013] The annular bar that restricts the surrounding groove can act as a guiding element, which has high magnetic resistance due to its small axial extension.

[0014] When a surface area with increased magnetic resistance is formed by a threaded profile, excellent guidance and high magnetic resistance can be achieved in particular.

[0015] Alternatively, it can be proposed that at least one guide element of the emergency operation valve body is formed from a component independent of the base of the valve body. This simplifies the manufacturing of the base and allows the use of a friction-optimized guide element. Attached Figure Description

[0016] The invention will be explained in more detail with reference to the following accompanying drawings. The drawings show:

[0017] Figure 1 This describes the installation status of the damping valve device on the shock absorber;

[0018] Figure 2 This is a cross-sectional view of a damping valve assembly;

[0019] Figure 3 yes Figure 2 A cross-sectional view of the emergency operation valve body component;

[0020] Figure 4 yes Figure 3 Top view;

[0021] Figure 5 yes Figure 3 Front view;

[0022] Figures 6 to 8 yes Figure 3 Alternative implementation methods. Detailed Implementation

[0023] exist Figure 1In this shock absorber, a cylinder body 1 is provided, within which a piston rod 3 is axially movable. A guiding and sealing unit 7 guides the piston rod 3 out from the upper end of the cylinder body. Inside the cylinder body 1, a piston unit 9 with a piston valve assembly 11 is fixed at the piston rod 3. The lower end of the cylinder body 1 is closed by a bottom plate 13 with a bottom valve assembly 15. The cylinder body 1 is surrounded by a container tube 17. This container tube 17 and the intermediate tube 5 form an annular space 19, which is a balance chamber. The space inside the cylinder body 1 is divided into a first working chamber 21a and a second working chamber 21b by the piston unit 9. Working chambers 21a and 21b are filled with damping fluid. The balance chamber 19 is filled with liquid up to the liquid level 19a and then filled with gas above this level. A first conductive section, namely a high-pressure section 23, is formed inside the balance chamber 19, which is connected to the second working chamber 21b through a hole 25 in the cylinder body 1. Immediately following this high-pressure section is an adjustable damping valve device 27, which is laterally mounted on the container pipe 17. Not shown, the second conducting section, i.e., the low-pressure section 29, is guided from the adjustable damping valve device 27 into the balance chamber 19.

[0024] If the piston rod 3 moves upward from the cylinder 1, the upper working chamber 21b shrinks. Overpressure forms in this upper working chamber 21b, which can only be released into the lower working chamber 21a through the piston valve assembly 11, provided the adjustable damping valve 27 is closed. If the adjustable damping valve 27 is open, fluid flows from the upper working chamber 21b through the high-pressure section 23 and the adjustable damping valve 27 into the balance chamber 19 simultaneously. In other words, the damping characteristics of the shock absorber when the piston rod 3 moves out are related to the more or less the adjustable damping valve 27 is opened or closed.

[0025] If the piston rod 3 moves into the cylinder 1, overpressure is created in the lower working chamber 21a. Liquid can be transferred from the lower working chamber 21a to the upper working chamber 21b via the piston valve assembly 11. Liquid displaced by the increasing piston rod volume within the cylinder 1 is discharged into the balance chamber 19 via the bottom valve assembly 15. In the upper working chamber 21b, since the flow resistance of the piston valve assembly 11 is less than that of the bottom valve assembly 15, an increasing pressure also occurs. This increasing pressure can flow into the balance space 19 through the high-pressure section 23 when the damping valve device 27 is open. This means that when the damping valve device 27 is open, even when the piston rod is in, the damper has a softer characteristic when the adjustable damping valve device 27 is open, and a stiffer characteristic when the damping valve device 27 is closed, just as it does when the piston rod is out. It can be determined that the flow direction through the bypass high-pressure section 23 is always the same, regardless of whether the piston rod moves in or out.

[0026] Figure 2The adjustable damping valve device 27 is shown in cross-section. In principle, the present invention can also be used for the damping valve device 27 located on the piston rod 3.

[0027] Figure 2 The adjustable damping valve device 27 is shown in cross-section. In principle, the present invention can also be used for the damping valve device 27 located on the piston rod 3.

[0028] The damping valve assembly 27 includes an actuator 31 with an excitation coil 33 for controlling a valve armature 35, which is at least indirectly connected to a pilot valve 37, which in turn determines the closing force at the main stage valve 39. The main stage valve 39 has a main stage valve body 41, the rear side of which forms the valve seat surface 43 of the pilot valve body 45.

[0029] In addition, the damping valve device 27 also has an emergency operation function based on the position of the emergency operation valve body 47, which is preloaded by the spring 48 toward the pilot valve body 45.

[0030] The valve armature 35 is movably supported in a sleeve-shaped magnetic yoke 49, wherein the magnetic yoke 49 has an pole plate 51 located on its bottom side, which is fixedly arranged relative to the valve housing 53. In this embodiment, the valve armature 35 is supported in the pole plate 51 and in the cover region 61 of the magnetic yoke 49 via a central armature rod 55 with intermediate connecting support sleeves 57 and 59.

[0031] Depending on the power supply of the excitation coil 33, the emergency operation valve body 47 switches between the emergency operation state and the normal operation state. The emergency operation valve body 47 is switched by the force caused by the magnetic flux of the excitation coil 33 passing through the magnetic yoke 49 and the pole plate 51.

[0032] A magnetic reluctance is arranged between the pole plate 51 and the valve body 53 to prevent short circuits in the magnetic flux relative to the pole plate 51. This reluctance is used to conduct the magnetic flux from the pole plate 51 to the emergency operating valve body 47, thereby applying the largest possible traction force to the emergency operating valve body 47 relative to the current intensity set for the excitation coil 35. When the current in the excitation coil exceeds a threshold current, this traction force overcomes the force of the spring 48, holding the emergency operating valve body 47 in the normal operating position. In the emergency operating position, the back side of the emergency operating valve body 47 rests against the pilot valve body 45. The closing force is then indirectly transmitted to the pilot valve body 45 by the spring 48. In the normal operating position of the emergency operating valve body 47, a gap exists between the emergency operating valve body 47 and the pilot valve body 45, regardless of the operating position of the pilot valve body 45. It can be specified that in the normal operating position, the emergency operating valve body 47 rests against the pole plate 51.

[0033] like Figure 2As shown, the magnetic reluctance is formed by the wall thickness reduction portion 63 caused by the increase in the inner diameter of the magnetic yoke 49.

[0034] The magnetic yoke 49 has a multi-level stepped inner contour, wherein a wall thickness reduction portion 63 is formed through the inner shoulder 65 of the magnetic yoke 49, and the pole disk 51 is also axially supported on the inner shoulder.

[0035] The wall thickness reduction portion 63 of the yoke 49 is confined axially to a minimum longitudinal section, essentially limited to the axial range of the contact surface 67 between the pole plate 51 and the yoke 49. The contact surface 67 also serves as a pressure surface for force-transmitting connection with the valve housing 53. Furthermore, the wall thickness reduction portion 63 enhances the radial widening capability of the yoke 49 for accommodating the pole plate 51.

[0036] The valve housing 53 has an axial support surface 69 for the excitation coil 33, wherein a wall thickness reduction portion 63 extends axially from this support surface 69 toward the cover region 61 of the yoke 49. Thus, the area of ​​the wall thickness reduction portion 63 is entirely within the internal space confined by the excitation coil 33. The area of ​​the valve housing 53 located below the excitation coil 33 can be utilized and optimized for other functions.

[0037] In principle, the yoke 49 and the valve body 53 can be manufactured as two pieces and then joined together. Preferably, the yoke 49 and the valve body 53 are manufactured as a single, seamless piece. This one-piece structure avoids the manufacturing tolerances that may arise with a two-piece structure.

[0038] Optionally, the yoke 49 has a second magnetic reluctance 71 within a sleeve-shaped section, which is connected in parallel with the magnetic flux path from the yoke 49 to the valve armature 35. The second magnetic reluctance 71 is also formed by a wall thickness reduction portion, but this wall thickness reduction portion is formed by an externally surrounding groove. Starting from the region with the deepest radial depth of the groove, i.e., the minimum wall thickness, the wall thickness of the yoke 49 gradually increases in the direction toward the pole plate 51. The pole plate 51 further rests directly against the shoulder of the yoke 49. Therefore, a recessed stepped portion for the valve armature is formed from the second wall thickness reduction portion 71 to the region above the pole plate 51. In the direction toward the valve armature 35, the pole plate 51 can be constructed as a flat disc.

[0039] When the excitation coil 33 is energized, a closed magnetic flux path is formed around it. The valve housing cover 73 is a component with excellent magnetic flux conduction performance, and it is in direct contact with the yoke 49 in the region of the through opening 75 at the bottom 77. The magnetic flux enters the yoke 49 at this location. Continuing along the magnetic flux path to the second wall thickness reduction section 71, a section of the wall cross-section of the yoke 47 is optimized for the radial entry of the magnetic flux into the valve armature 35. Due to the second magnetic reluctance 71, the magnetic flux passes through the valve armature 35 and then switches to re-enter the yoke 49 towards the pole plate 51. The yoke and the pole plate together form a tauchprofil for the valve armature 35, that is, as the current increases and the valve armature 35 approaches the pole plate 51, the axial overlap with the yoke 49 increases in the region between the second magnetic reluctance 71 and the first magnetic reluctance 63. Furthermore, as the overlap increases, the conductive cross-section on the yoke 49 continuously increases in the direction towards the pole plate 51. When they are close enough, the magnetic flux enters the pole plate 51 directly from the valve armature 35.

[0040] The emergency operation valve body 47 has a blind hole opening 79 facing the pole plate 51, which together with the protruding shoulder 81 of the pole plate 51 forms a recessed profile with minimal axial overlap. When the excitation coil 33 is energized, a traction force can be applied to the emergency operation valve body 47, wherein magnetic flux can enter the valve housing 53 through the surrounding circumferential side 83 of the emergency operation valve body 47, thereby closing the magnetic flux of the excitation coil 33.

[0041] Figures 3 to 5 Shown in different views according to Figure 2 The emergency operating valve body. To maximize the traction force acting on the emergency operating valve body 47, the circumferential side region 85 of the emergency operating valve body has higher magnetic resistance.

[0042] exist Figures 3 to 5 In the middle, the circumferential side region 85 is formed by a shoulder 87, which forms an air gap with the adjacent magnetic flux conduction member, which in this example is the valve housing 53. The shoulder 87 is located at the end of the emergency operation valve body 47 facing the pole plate 51.

[0043] Especially combined Figure 4 and Figure 5 As can be seen, the shoulder 87 is divided into multiple individual recesses 91 by a plurality of guide elements 89 configured as guide strips. The guide strips 89 are sufficiently narrow in the circumferential direction, thus having high conduction resistance. Therefore, there are more than three guide strips. The recesses 91 are open at the end sides. Therefore, there is no undercut, which would increase the difficulty of demolding the emergency operation valve body 47 from, for example, a sintering mold.

[0044] like Figure 6As shown, for the emergency operation valve body 47, a guide element configured as a guide protrusion 93 can also be alternatively arranged in the shoulder 87.

[0045] exist Figure 7 In the circumferential side region 85, at least one surrounding groove 95 is formed, and an annular strip 97 constraining the surrounding groove acts as a guide element. At least one guide element 89, 93, 97 of the emergency operation valve body 47 can be formed seamlessly in one piece, or it can be formed from a component independent of the base 99 of the emergency operation valve body 47. In particular, in the case of independent components, for example... Figure 7 As shown on the right, friction-optimized materials, such as Teflon rings or plastic bumps, can be used for the at least one guide element 93, 97.

[0046] According to Figure 8 In the embodiment of the emergency operation valve body 47, the surface region 85 with increased magnetic resistance is formed by a threaded profile portion 103. This threaded profile portion 103 can be easily machined. Furthermore, a sharp threaded surface with extremely high conduction resistance can also be provided. List of reference numerals in the attached diagram: 1. Cylinder block 3 Piston rod 5. Intermediate pipe 7. Guiding and sealing unit 9 Piston Units 11 Piston Valve Assembly 13. Base plate 15. Bottom Valve Assembly 17 Container tube 19. Circular Space Working chambers 21a and 21b 23 High-voltage section 25 holes 27 Damping valve device 29 Low-voltage section 31 Actuator 33 Excitation Coil 35 Valve armature 37 Pilot valve 39 Main stage valve 41 Main stage valve body 43 Valve seat face 45 Pilot valve body 47 Emergency Operation Valve Body 48 Springs 49 yoke body 51 Extreme Disk 53 valve housing 55 Armstock 57 Support sleeve 59 Support sleeve 61 Covered Area 63. Section with reduced wall thickness 65 Shoulders 67 Contact surface 69 Support surface 71 Second magnetoresistive 73 Valve housing cover 75 Through opening 77 Bottom 79 Blind hole opening 81 Shoulders 83 Circumferential side 85 circumferential lateral region 87 Shoulders 89. Guiding element 91 Notch 93 Guide bump 95 Groove 97 Circular stripes 99 Emergency operation valve body base 101 Independent component as a guiding element 103 Thread profile.

Claims

1. An adjustable damping valve device (27), the damping valve device comprising an actuator (31) having an excitation coil (33) and a valve armature (35), wherein, The valve armature (35) is movably supported in a sleeve-shaped magnetic yoke (49), wherein the magnetic yoke (49) has a pole plate (51) located on the bottom side, the pole plate being fixedly arranged relative to the valve housing (53), wherein the emergency operation valve body (47) switches between an emergency operation state and a normal operation state according to the power supply of the excitation coil (33), wherein the emergency operation valve body (47) is switched by the force caused by the magnetic flux of the excitation coil (33) passing through the magnetic yoke (49) and the pole plate (51), wherein the outer peripheral side surface (83) of the emergency operation valve body acts as the magnetic flux transmission surface, characterized in that the emergency operation valve body (47) has a circumferential side surface region (85) with increased magnetic resistance.

2. The adjustable damping valve device (27) according to claim 1, characterized in that, The circumferential side region (85) is formed by a shoulder (87), which forms an air gap relative to the adjacent magnetic flux conduction member (53).

3. The adjustable damping valve device (27) according to claim 2, characterized in that, The shoulder (87) is divided into multiple individual notches (91) by multiple guide elements (89) configured as guide strips.

4. The adjustable damping valve device (27) according to claim 3, characterized in that, The notch (91) is open at the end.

5. The adjustable damping valve device (27) according to any one of claims 1 to 4, characterized in that, A guide element configured as a guide protrusion (93) is arranged in the shoulder (87).

6. The adjustable damping valve device (27) according to any one of claims 1 to 5, characterized in that, The circumferential side region (85) is formed by at least one surrounding groove (95).

7. The adjustable damping valve device (27) according to claim 6, characterized in that, The annular bar (97) that restricts the surrounding groove (95) acts as a guide element.

8. The adjustable damping valve device (27) according to claim 1, characterized in that, The circumferential side region (85) with increased magnetic resistance is formed by the threaded profile portion (103).

9. The adjustable damping valve device (27) according to any one of claims 1 to 7, characterized in that, At least one guide element (89, 93, 97) of the emergency operation valve body (47) is formed by a component independent of the base (99) of the emergency operation valve body (47).

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