Adjustable damping valve device

Abstract

Adjustable damping valve assembly comprising an actuator with a solenoid coil and a valve armature, which is radially guided in a return body by means of radially projecting and axially spaced guide surfaces provided on the valve armature.

Description

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

[0002] DE 10 2009 016 464 A1 discloses an adjustable damping valve device comprising a pre-stage valve and a main-stage valve. The pre-stage valve is actuated by an actuator consisting of a solenoid coil and a magnet armature. The magnet armature also consists of several individual parts, namely a central shaft and an annular valve armature.

[0003] The magnet armature is radially mounted by two spring plates, a first of which is located in the base of the magnetic return element, and a second of which is located in a pole plate on the housing. This design principle presents two potential sources of error. There may be a misalignment between the shaft and the valve armature. Furthermore, the two spring plates may exhibit a slight radial offset from each other. Although both misalignment errors are very minor in themselves, they nevertheless lead to a functional disadvantage.

[0004] DE 198 22 448 A1 also relates to an adjustable damping valve device with a pilot valve and a main valve. In contrast, the valve armature is radially mounted in the return path body. Instead, the return path body has radial projections with axially spaced guide surfaces. The disadvantage of this design is that during the axial movement of the valve armature, the contact area and thus the transmission cross-section fluctuates in size and thus the resistance for the magnetic flux of the actuator between the valve armature and the return path body. Furthermore, the volume of the valve armature usable for the magnetic flux varies if, for example, one end of the valve armature is moved beyond the contact area on the return path body.

[0005] The object of the present invention is to improve the mounting of the valve armature within the damping valve device.

[0006] The task is solved by the radially projecting guide surfaces on the valve armature.

[0007] The advantage is that there is always a constant, large transmission cross-section for the magnetic flux in the area of ​​the guide surfaces. Due to the arrangement of the guide surfaces at the respective end areas of the valve armature, the entire volume of the valve armature can be used to transmit the magnetic flux.

[0008] A further advantage is that the guide surfaces of the valve armature are located on its outer surface, making them very accessible for manufacturing. Even with modern manufacturing methods, surfaces on an inner surface are more difficult to manufacture, e.g., due to the limited space for tool access or for measuring the guide surfaces.

[0009] In one embodiment, at least one of the guide surfaces is formed by an additional element. There are several possibilities for this.

[0010] The additional element can be formed by an additional ring, for example, which is pressed on. The forces acting on the ring are very low, so there are no particularly stringent requirements for the connection between the ring and the valve armature.

[0011] There are various optimization approaches for an additional ring. For example, the additional ring can be made at least partially of a material optimized for magnetic flux. A copper ring, for example, would be conceivable.

[0012] Alternatively, the additional ring can be made at least partially of a friction-optimized material, such as Teflon, which is very thin as a film and therefore has little resistance.

[0013] Another possibility is for the additional ring to be formed by a partial coating on the valve armature. The coating can be very thin and does not require any space for attaching a ring to the valve armature. A possible coating could be a chrome layer, for example.

[0014] According to an advantageous subclaim, the at least one guide surface can be manufactured using a non-cutting forming process. The guide surface can be pressed out of the outer surface of the valve armature, for example, using a rolling tool.

[0015] Particularly in large-scale production, it can be stipulated that the valve armature is manufactured using a sintering process.

[0016] The invention will be explained in more detail with reference to the following description of the figures.

[0017] It shows: Fig. 1 vibration damper with an adjustable damping valve device Fig. 2 Damping valve device according to Fig. 1 on average Fig. 3 Alternative design of a damping valve device according to Fig. 2

[0018] In Fig. 1, a vibration damper comprises a cylinder 1 in which a piston rod 3 is arranged for axial movement. A guide and sealing unit 7 guides the piston rod 3 out of the upper end of the cylinder. Within the cylinder 1, a piston unit 9 with a piston valve arrangement 11 is attached to the piston rod 3. The lower end of the cylinder 1 is closed off by a base plate 13 with a base valve arrangement 15. The cylinder 1 is enclosed by a container tube 17. The container tube 17 and an intermediate tube 5 form an annular space 19, which represents a compensation chamber. The space within the cylinder 1 is divided by the piston unit 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 compensation chamber 19 is filled with fluid up to the level 19a and with gas above.Within the compensation chamber 19, a first line section, namely a high-pressure section 23, is formed, which communicates with the second working chamber 21b via a bore 25 of the cylinder 1. This high-pressure section is followed by an adjustable damping valve device 27, mounted laterally on the container tube 17. A second line section, namely a low-pressure section 29, leads from this section (see ). Fig. 2, into the compensation chamber 19.

[0019] When the piston rod 3 extends upwards out of 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 through the piston valve assembly 11 as long as the adjustable damping valve 27 is closed. When the adjustable damping valve device 27 is open, fluid simultaneously flows from the upper working chamber 21b through the high-pressure section 23 and the adjustable damping valve device 27 into the compensation chamber 19. The damping characteristics of the vibration damper when the piston rod 3 extends therefore depend on whether the adjustable damping valve device 27 is more or less open or closed.

[0020] When the piston rod 3 retracts into the cylinder 1, an overpressure builds up in the lower working chamber 21a. Fluid can flow upwards from the lower working chamber 21a through the piston valve arrangement 11 into the upper working chamber 21b. The fluid displaced within the cylinder 1 by the increasing piston rod volume is expelled through the base valve arrangement 15 into the compensation chamber 19. Since the flow resistance of the piston valve arrangement 11 is lower than the flow resistance of the base valve arrangement 15, an increasing pressure also occurs in the upper working chamber 21b. This increasing pressure can, when the damping valve device 27 is open, flow through the high-pressure section 23 into the compensation chamber 19.This means that when the damping valve device 27 is open, the vibration damper has a softer characteristic during retraction when the adjustable damping valve device 27 is open and a harder characteristic when the damping valve device 27 is closed, just as it does when the piston rod is extended. 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.

[0021] The Fig. 2 shows the adjustable damping valve device 27 according to the Fig. 1 in a sectional view. In principle, the adjustable damping valve device 27 can also be arranged on the piston rod 3 or in a valve block separate from the outer container tube 17. Furthermore, a separate damping valve device 27 can be provided for each direction of movement of the piston rod. Within a housing 31, the damping valve device 27 comprises a main stage valve 33 and a pre-stage valve 35, with which an external force is applied to the main stage valve 33. The precise structural design of the pre-stage and main stage valves 33; 35 is known, for example, from DE 10 2013 218 658 A1.

[0022] An actuator 37, which comprises a solenoid coil 39 and a valve armature 41, serves to control the pre-stage valve 35. A central axis 43 of the valve armature 41 extends through a housing-side through-hole 45 in a pole disk 47, which, however, does not perform a guiding function for the central axis 43 and thus for the valve armature 41. There is a press fit between the valve armature 41 and the central axis 43. This configuration, however, is to be understood only as an example.

[0023] The valve armature 41 slides in a sleeve-shaped return body 49, which extends within the solenoid coil 39 and has a bottom 51 at its end. An inner sliding surface 53 of the return body 49 has a constant diameter. However, this feature is not mandatory.

[0024] It is essential that radially projecting guide surfaces 55; 57 are provided on the valve armature 41. The two axially spaced guide surfaces 55; 57 are provided at the end region of each outer circumferential surface 59 of the valve armature and are operatively connected to the sliding surface 53 of the return element 49 with minimal play. The conduction resistance to the magnetic flux of the solenoid coil 39 is minimal at the transition from the sliding surface 53 into the valve armature 41 or from the valve armature 41 via the guide surfaces 55; 57 into the sliding surface 53.

[0025] The Fig. Figure 2 shows the simplest embodiment of the invention, in which the guide surfaces 55; 57 are formed integrally with the valve armature 41. The at least one guide surface 55; 57 can be manufactured using a non-cutting forming process. For this purpose, a roller tool can be used, for example, which creates a circumferential collar with the radial guide surfaces 55; 57 from the solid material of the valve armature 41 by pressing and the associated volume displacement. Alternatively, the valve armature 41 can be manufactured using a sintering process.

[0026] In the design of the valve armature 41 according to Fig.3, the at least one guide surface 55; 57 is formed by an additional element 61; 63. Optionally, the additional element 61; 63 can be formed by an additional ring. The additional ring can be made at least partially of a material optimized for the magnetic flux of the friction-optimized element. The advantage is that the material of the valve armature 41 does not necessarily determine the technical properties of the guide surfaces 55; 57. The additional ring 61; 63 can also be formed by a partial coating on the valve armature 41, whereby the installation space required for the guide surfaces 55; 57 can be reduced compared to an additional ring. Reference symbol 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 Annular space 21a / b Working Chamber 23 high-pressure section 25 bore 27 Damping valve device 29 Low-pressure section 31 housings 33 Main stage valve 35 Pre-stage valve 37 Actuator 39 Solenoid coil 41 valve anchor 43 Axis 45 passage opening 47 Pole disc 49 Return body 51 Floor 53 Sliding surface 55 guide surface 57 Guide surface 59 Shell surface of the valve armature 61 additional element for guide surface 63 additional element for guide surface QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2009 016 464 A1

[0002] DE 198 22 448 A1

[0004] DE 10 2013 218 658 A1

[0021]

Claims

[1] Adjustable damping valve device (27), comprising an actuator (37) with a magnetic coil (39) and a valve armature (41) which is radially guided in a return body (49) by means of radially projecting and axially spaced guide surfaces (55; 57), characterized by that the radially projecting guide surfaces (55; 57) are formed on the valve armature (41). [2] Adjustable damping valve device according to claim 1, characterized by that at least one of the guide surfaces (55; 57) is formed by an additional element (61; 63). [3] Adjustable damping valve device according to claim 2, characterized by that the additional element (61; 63) is formed by an additional ring. [4] Adjustable damping valve device according to claim 3, characterized by that the additional ring (61; 63) consists at least partially of a material optimized for the magnetic flux. [5] Adjustable damping valve device according to claim 3, characterized by that the additional ring (61; 63) consists at least partially of a friction-optimized material. [6] Adjustable damping valve device according to at least one of claims 3 to 5, characterized by that the additional ring (61; 63) is formed by a partial coating on the valve armature. [7] Method for producing an adjustable damping valve device according to claim 1, characterized by that the at least one guide surface (55; 57) is produced by means of a non-cutting forming process. [8] Method for producing an adjustable damping valve device according to claim 1, characterized by that the valve armature (41) is produced by means of a sintering process.

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