Adjustable damping valve device with emergency operation function for shock absorber

Abstract

Adjustable damper 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 formed by a wall thickness reduction of the yoke body.

Description

Technical Field

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

[0002] Document DE 10 2015 200 348 A1 relates to a general-purpose damping valve device with 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 provided 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 magnetic yoke in which a valve armature is slidably supported. The yoke includes an annular body through which the valve armature is axially passed and supported. 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 form magnetic reluctance by reducing the wall thickness of the magnetic yoke.

[0007] One important advantage is that the sleeve-shaped section of the magnetic yoke no longer uses a multi-piece design.

[0008] In another advantageous embodiment of the invention, the reduced wall thickness portion is formed by the enlarged inner diameter portion of the magnetic yoke.

[0009] Furthermore, the first wall thickness reduction section is formed by a shoulder on the inner side of the magnetic yoke, and the pole plate is axially supported at this shoulder.

[0010] Here, the reduced wall thickness of the yoke is limited to the axial extension range of the contact surface between the pole disk and the yoke. Thus, the pole disk is compactly arranged inside the yoke, while the yoke's structural geometry is simple.

[0011] Furthermore, the valve housing has an axial support surface for the excitation coil, from which the wall thickness reduction portion extends axially. This feature also facilitates the implementation of the wall thickness reduction portion.

[0012] Preferably, the magnetic yoke and valve housing are constructed as a single, seamless piece. This reduces the manufacturing cost of the damping valve assembly.

[0013] Optionally, the yoke has a second magnetic reluctance that runs parallel to the magnetic flux path from the yoke to the valve armature. This second magnetic reluctance is also formed by a portion of the yoke with a reduced wall thickness.

[0014] The dimensions of these two magnetoresistors can be determined independently of each other based on their impeding function. Attached Figure Description

[0015] The invention is explained in more detail with reference to the following description of the accompanying drawings. The drawings show:

[0016] Figure 1 This describes the installation status of the damping valve device on the shock absorber;

[0017] Figure 2 This is a cross-sectional view of a damping valve assembly. Detailed Implementation

[0018] exist Figure 1 In 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 to 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 forms 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. Following this high-pressure section is an adjustable damping valve device 27, laterally mounted on the container pipe 17. The second conduction section (see...) Figure 2 The low-pressure section 29 is guided from the adjustable damping valve device 27 into the balance chamber 19.

[0019] 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 device 27 is closed. If the adjustable damping valve device 27 is open, liquid flows from the upper working chamber 21b through the high-pressure section 23 and the adjustable damping valve device 27 simultaneously into the balance chamber 19. 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 device 27 is opened or closed.

[0020] 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 gradually 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, a gradually increasing pressure also occurs. This gradually increasing pressure can flow into the balance chamber 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 its bottom side, which is fixedly arranged relative to the valve housing 53. In this embodiment, the valve armature 35 is supported by a central armature rod 55, which connects a support sleeve 59 located at the pole plate 51 and a support sleeve 57 located at the cover region 61 of the magnetic yoke 49.

[0025] 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.

[0026] 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.

[0027] like Figure 2 As shown, the magnetic reluctance is formed by a wall thickness reduction portion 63 formed by the expansion of the inner diameter of the magnetic yoke 49.

[0028] 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.

[0029] The wall thickness reduction portion 63 of the yoke 49 is confined axially to a minimum longitudinal section, essentially within the axial extension 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.

[0030] 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 the 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 region defined 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.

[0031] 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 constructed as a single, seamless piece. This one-piece structure avoids the manufacturing tolerances that may arise with a two-piece structure.

[0032] Optionally, the yoke 49 has a second magnetic reluctance 71 within a sleeve-shaped section, which runs parallel to 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 reduction is achieved through 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 towards 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. The pole plate 51 facing the valve armature 35 can be constructed as a flat disc shape.

[0033] 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, the cross-section of the wall of the yoke 47 is optimized to allow the magnetic flux to enter the valve armature 35 radially. 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 gradually increases towards the pole plate 51. When they are close enough, the magnetic flux enters the pole plate 51 directly from the valve armature 35.

[0034] The emergency operation valve body 47 has a blind hole opening 79 facing the pole plate 51. This blind hole opening, together with the protruding shoulder 81 of the pole plate 51, forms a recessed profile and has a small 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 circumferential side 81 of the emergency operation valve body 47, thereby closing the magnetic flux of the excitation coil 33. 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. Side view.

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 a magnetic reluctance is arranged between the pole plate (51) and the valve housing (53), characterized in that the magnetic reluctance is formed by a wall thickness reduction portion (63) of the magnetic yoke (49).

2. The adjustable damping valve device (27) according to claim 1, characterized in that, The first wall thickness reduction section (63) is formed by the inner diameter expansion section of the magnetic yoke (49).

3. The adjustable damping valve device (27) according to claim 2, characterized in that, The first wall thickness reduction portion (63) is formed by the shoulder (65) on the inner side of the magnetic yoke (49), and the pole plate (51) is axially supported on the shoulder.

4. The adjustable damping valve device (27) according to claim 2 or 3, characterized in that, The wall thickness reduction portion (63) of the magnetic yoke (49) is substantially limited to the axial extension range of the contact surface (67) between the pole plate (51) and the magnetic yoke (49).

5. The adjustable damping valve device (27) according to any one of claims 1 to 4, characterized in that, The valve housing (53) has an axial support surface (69) for the excitation coil (33), wherein the wall thickness reduction portion (63) extends axially from the support surface (69).

6. The adjustable damping valve device (27) according to any one of claims 1 to 5, characterized in that, The magnetic yoke (49) and the valve housing (53) are constructed as a single seamless piece.

7. The adjustable damping valve device (27) according to any one of claims 1 to 6, characterized in that, The yoke (49) has a second magnetic resistance (71) that runs parallel to the magnetic flux path from the yoke (49) to the valve armature (35).

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