STABILIZER ASSEMBLY WITH ACTUATOR FOR A TWO-TRACK VEHICLE

Abstract

A stabilizer assembly for a two-track vehicle comprises: a first and a second stabilizer section; a spring element between the stabilizer sections; a hydraulic actuator having an actuator outer part and an actuator inner part, each of which is non-rotatably connected to one of the stabilizer sections, and an intermediate element connected to the actuator outer part and actuator inner part respectively via outer and inner engagement means, wherein one of the engagement means has a pitch component in the axial direction and the other runs parallel to the longitudinal axis, so that a relative rotational movement of the actuator parts is converted into an axial movement of the intermediate element, wherein the intermediate element pressurises a first and second hydraulic chamber respectively; the hydraulic chambers being hydraulically connected to one another with interposition of a control element.

Claims

1.-15. (canceled)

16. A stabilizer assembly for a two-track vehicle comprising: a first stabilizer section; a second stabilizer section; a hydraulic actuator having an actuator outer part which is connected to one of the first and second stabilizer sections in a rotationally fixed manner, and having an actuator inner part which is connected to the other one of the first and second stabilizer sections in a rotationally fixed manner, and an intermediate element connected to the actuator outer part via outer engagement means and connected to the actuator inner part via inner engagement means, wherein one of the outer and inner engagement means has a pitch component in the axial direction and the other one of the outer and inner engagement means extends parallel to the longitudinal axis so that a relative rotational movement between the actuator outer part and the actuator inner part is converted into an axial movement of the intermediate element, wherein the intermediate element pressurises a first hydraulic chamber when moving in a first direction and pressurises a second hydraulic chamber when moving in the opposite second direction; wherein a spring element is arranged between the first stabilizer section and the second stabilizer section; and wherein the first hydraulic chamber and the second hydraulic chamber are hydraulically connected to each other with a control element being interposed therebetween.

17. The stabilizer assembly according to claim 16, wherein both of a first hydraulic connector for the first hydraulic chamber and a second hydraulic connector for the second hydraulic chamber are connected to the actuator outer part.

18. The stabilizer assembly according to claim 17, wherein a first connecting line between the first hydraulic connector and the control element, and a second connecting line between the second hydraulic connector and the control element, are both configured rigid or flexible.

19. The stabilizer assembly according to claim 16, wherein the actuator outer part is configured as a housing part, and that the actuator inner part is configured as a hollow shaft, wherein one of the actuator outer part and the actuator inner part is connected to the first stabilizer section in a rotationally fixed manner, and the other one of the actuator outer part and the actuator inner part is connected to the second stabilizer section in a rotationally fixed manner.

20. The stabilizer assembly according to claim 19, wherein the spring element is configured as a torsion spring which is arranged functionally parallel to the actuator between the first stabilizer section and the second stabilizer section, wherein the torsion spring extends axially through the actuator inner part designed as hollow shaft, and includes a first end portion connected in a rotationally fixed manner to the first stabilizer section and a second end portion connected in a rotationally fixed manner to the second stabilizer section.

21. The stabilizer assembly according to claim 16, wherein the intermediate element has a first end portion associated with the first hydraulic chamber and a second end portion associated with the second hydraulic chamber, wherein one of the first end portion and the second end portion of the intermediate element is sealed relative to the actuator outer part by an outer seal and is seal-free relative to the actuator inner part, and the other one of the first end portion and the second end portion of the intermediate element is sealed relative to the actuator inner part by an inner seal and is seal-free relative to the actuator outer part.

22. The stabilizer assembly according to claim 16, wherein the outer engagement means run at an angle to the longitudinal axis and the inner engagement means run parallel to the longitudinal axis, or, wherein the outer engagement means run parallel to the longitudinal axis and the inner engagement means run at an angle to the longitudinal axis.

23. The stabilizer assembly according to claim 16, wherein the outer engagement means of the intermediate element are configured in the form of helical toothing which engages in a helically rotatable manner with a respective counter-toothing of the actuator outer part.

24. The stabilizer assembly according to claim 16, wherein the inner engagement means of the intermediate element are configured as splines which engage corresponding shaft splines of the actuator inner part in a rotationally fixed and axially displaceable manner.

25. The stabilizer assembly according to claim 16, wherein the axial extension of the engagement means running parallel to the longitudinal axis is shorter than an axial length of the intermediate element.

26. The stabilizer assembly according to claim 16, wherein the control element includes a damping unit and a pressure accumulator, with the damping unit being configured as a semi-active or active unit.

27. The stabilizer assembly according to claim 26, wherein the damping unit comprises a frequency-selective valve which has a variable damping force as a function of an oscillation frequency of the stabilizer assembly, wherein the frequency-selective valve is configured to have a damping force that at high excitation frequencies of more than 5 Hz is lower than at low excitation frequencies of less than 2 Hz.

28. The stabilizer assembly according to claim 16, wherein the control element is arranged at least partially with axial overlap to the actuator and has a control housing which is firmly connected to the actuator outer part.

29. The stabilizer assembly according to claim 16, wherein the control element is arranged at least partially axially offset with respect to the actuator, the control housing being firmly connected at least indirectly to the actuator outer part.

30. The stabilizer assembly according to claim 29, wherein the control housing is connected to the stabilizer section connected to the actuator outer part via a connecting element, the connecting element being able to absorb angular differences.

Description

BRIEF SUMMARY OF THE DRAWINGS

[0024] Examples of embodiments are explained below with reference to the figures in the drawings. Herein:

[0025] FIG. 1 shows a stabilizer assembly according to the invention in a first embodiment;

[0026] FIG. 2 shows the actuator of the stabilizer assembly from FIG. 1 in detail in longitudinal section;

[0027] FIG. 3 shows the stabilizer assembly from FIG. 1 schematically;

[0028] FIG. 4 schematically shows a stabilizer assembly in a second embodiment;

[0029] FIG. 5 schematically shows a stabilizer assembly in a third embodiment;

[0030] FIG. 6 shows a stabilizer assembly in a further embodiment with modified connection of the control unit;

[0031] FIG. 7 shows a stabilizer assembly in a further embodiment with a modified arrangement of the control unit;

[0032] FIG. 8 shows an actuator assembly in a modified implementation for a stabilizer assembly;

[0033] FIG. 9 shows an actuator assembly in a modified implementation for a stabilizer assembly.

DESCRIPTION

[0034] FIGS. 1 to 3, which are described together below, show a stabilizer assembly 2 in a first embodiment.

[0035] The stabilizer assembly 2 comprises a first stabilizer section 3 and a second stabilizer section 4, which are coupled to one another via a spring element 5 so as to be rotatable relative to each other, with the stabilizer being operable with a first spring characteristic. The stabilizer assembly 2 further comprises a hydraulic actuator 6, via which the two stabilizer sections 3, 4 can be hydraulically coupled to each other in a functionally parallel arrangement to the spring element 5, wherein the stabilizer can be operated with a second spring characteristic.

[0036] The actuator 6 comprises an actuator outer part 7, which is non-rotatably connected to the first stabilizer section 3, an actuator inner part 8, which is non-rotatably connected to the second stabilizer section 4, and an intermediate element 9 arranged radially between the two actuator parts 7, 8. The actuator outer part 7 is formed as a housing part, and the actuator inner part 8 as a hollow shaft, without being restricted thereto. The actuator inner part 8 is mounted by suitable bearing means 10, 11 so as to be rotatable about the longitudinal axis A in the actuator outer part 7 and is sealed with respect thereto by suitable sealing elements 12, 13. The actuator outer part 7 comprises a connecting portion 14 which is firmly connected to the first stabilizer section 3. At the opposite end, the actuator inner part 8, formed as a hollow shaft, has a connecting portion 15 to which the second stabilizer section 4 is firmly connected. The spring element 5 is configured as a torsion bar spring, wherein a first spring end 16 is connected in a rotationally fixed manner to the connecting portion 14 of the actuator outer part 7 via a plug-in connection, and a second spring end 17 is connected in a rotationally fixed manner to the connecting portion 15 of the actuator inner part 8 via a plug-in connection. When the vehicle rolls, the two stabilizer sections 3, 4 and, respectively, the actuator parts 7, 8 connected thereto are rotated relative to each other so that the interposed spring element 5 is twisted and damps the rolling motion with a first spring rate.

[0037] A second spring rate results from the actuator 6, the intermediate element 9 of which is arranged between the actuator outer part 7 and the actuator inner part 8 in an axially movable manner like a piston. The intermediate element 9 is part of a rotation-translation converter, which is configured in such a way that a rotational movement of the two actuator parts 7, 8 relative to each other is or can be converted into an axial movement of the intermediate element 9. For this purpose, outer engagement means 18 are provided, with which the intermediate element 9 engages the actuator outer part 7, in a form-fitting manner, as well as inner engagement means 19, with which the intermediate element 9 engages the actuator inner part 8, in a form-fitting manner. In the present embodiment, the outer engagement means 18 have an incline component in the axial direction, whereas the inner engagement means 19 are axially incline-free with respect to the longitudinal axis A, respectively run parallel thereto. It is understood that a reverse assignment of the engagement means with and without a gradient component to the outer and inner actuator part is also possible.

[0038] The engagement means 18 with an axial pitch component are provided in the form of a helical arrangement, in which an outer helical toothing 29 of the intermediate element 9 engages in a counter-part inner helical toothing 30 of the actuator outer part 7 in such a way that the intermediate element and the actuator outer part can be rotated against each other in a helical manner. The engagement means 19 without an axial pitch component are configured in the form of a splined toothing, wherein an inner hollow shaft toothing 31 of the intermediate element 9 engages a counter-part shaft toothing 32 of the actuator inner part 8 in a rotationally fixed and axially movable manner. For sufficient axial moveability of the intermediate element 9 relative to the actuator inner part 8, the effective axial length of the axis-parallel engagement means 19 is shorter than the axial length of the intermediate element 9, e.g., shorter than 0.5 times the axial length of the intermediate element.

[0039] When moving the intermediate element 9 in a first axial direction R1, a first hydraulic chamber 20 is pressurised. When moving in the opposite second direction R2, a second hydraulic chamber 21 is pressurised, which is arranged on the opposite side of the piston element. The two hydraulic chambers 20, 21 are hydraulically sealed against each other by the piston element and hydraulically connected to each other with interposition of a control element 22. This includes the possibility that the two hydraulic chambers 20, 21 are hydraulically connectable to each other via the control element 22, i.e., the hydraulic chambers are connected to each other in at least one condition of the control element 22.

[0040] For sealing the hydraulic chambers 20, 21, an inner seal 24 is provided at a first end portion 23 of the intermediate element 9, which seals the first hydraulic chamber 20 to the actuator inner part 8, with the first end portion 23 being seal-free to the actuator outer part 7. An outer seal 26 is provided at the second end portion 25 of the intermediate element 9, which seals the second hydraulic chamber 21 to the actuator outer part 7, with the second end section 25 being seal-free to the actuator inner part 8. Thus, only two seals 24, 26 are required to seal the intermediate element 9 from the two hydraulic chambers 20, 21. The end portions 23, 25 can be provided as seal carriers which are firmly connected to the intermediate element 9, for example by means of welding.

[0041] A first hydraulic connector 27 to the first hydraulic chamber 20 and a second hydraulic connector 28 to the second hydraulic chamber 21 are provided on the actuator outer part 7. The connectors 27, 28 are hydraulically connected to the control element 22 via hydraulic lines 38, 39, which can be provided as rigid or flexible lines.

[0042] The control element 22 can be configured according to the requirements of the stabilizer assembly 2. By designing the control element 22 accordingly, the damping of the stabilizer assembly 2 can be adjusted as required depending on the speed of the forces and/or moments introduced, which in turn depend on the frequency of movement of the vehicle. Preferably, the hydraulic actuator 6 is designed in such a way that a low damping force is achieved at higher frequencies of, for example, greater than 2 Hz, e.g., greater than 5 Hz, and a greater damping force is generated at lower frequencies of, for example, less than 5 Hz, e.g., less than 2 Hz.

[0043] Various functional examples of the actuator 6 and, respectively, control element 22 are explained below with reference to FIGS. 3 to 5. It will be understood that the stabilizer assembly shown in FIG. 1 can be provided with any of the actuators or control elements described below.

[0044] In the example shown in FIG. 3, the actuator 6 with control element 22 is configured as a semi-active system. For this purpose, the control element 22 comprises a damping unit 33, which is hydraulically connected to the first and second hydraulic chambers 20, 21, and a pressure accumulator 34. In the present case, the damping unit 33 is configured in the form of a frequency-selective valve, which enables a variable damping force depending on an oscillation frequency and/or oscillation amplitude of the stabilizer assembly 2. The frequency-selective valve is designed in such a way that it has a lower damping force at higher excitation frequencies and/or vibration amplitudes, than at lower excitation frequencies and/or vibration amplitudes. The pressure accumulator 34 serves to compensate for temperature changes and can be integrated into the control element or connected to it as a separate element. An external control or circuit is not provided in this implementation.

[0045] FIG. 4 shows a second embodiment of the actuator 6, respectively the control unit 22, which is configured as an active system. This design largely corresponds to the design shown in FIG. 3, the description of which is referred to here in order to avoid repetition. The same details are marked with the same reference signs. In addition to the above system, two externally controllable switching valves 35, 36 are provided in this embodiment according to FIG. 4, which are arranged between the hydraulic chambers 20, 21 and the connectors of the frequency-selective valve. In the closed position of the switching valves 35, 36, which is shown in FIG. 4, the hydraulic connection between the chambers 20, 21 is interrupted so that the piston element 9 of the actuator 6 is prevented from moving axially. In this switching position, the actuator outer part 7 and the actuator inner part 8 are locked to each other in a torsionally rigid manner. This results in a comparatively hard spring behavior, bypassing the spring element 5. In the open position of the switching valves 35, 36, the two chambers 20, 21 communicate hydraulically with each other, so that the piston element 9 can move axially when the two stabilizer sections 3, 4 rotate relative to each other. Damping takes place in this switching position by means of the frequency-selective valve 33 variably depending on the vibration frequency of the stabilizer assembly. The frequency-selective valve 33 can be configured as in the embodiment according to FIG. 3.

[0046] FIG. 5 shows a third embodiment of the actuator 6, respectively control unit 22, which is provided as an active system. This example is characterized in that only a controllable switching valve 35 is provided, but no frequency-selective valve. The switching function is as described in FIG. 4. In the closed position of the switching valve 35, the two chambers 20, 21 are hydraulically separated from each other. In the open position of the switching valve 35, the two chambers 20, 21 communicate hydraulically with each other so that a relative rotation of the two stabilizer sections 3, 4 to each other is possible and the piston element 9 can be moved axially accordingly.

[0047] The design of the actuator 6 results in flexibility with regard to the configuration and arrangement of the control element 22. Various examples for the arrangement of the control element 22 are explained below with reference to FIGS. 6 to 9.

[0048] In the embodiment shown in FIG. 6, the control element 22 is arranged with axial overlap to the actuator 6. The housing 37 of the control element 22 is firmly connected to the actuator outer part 7, for example by gluing, welding or a screw connection. The connecting lines 38, 39 and/or connectors 27, 28 open into axial end portions of the actuator 6.

[0049] In the example shown in FIG. 7, the control element is arranged axially offset from the actuator 6. In this case, the control housing 37 is firmly connected to a stabilizer section 3 and is seated on it. The lines 38, 39 can be configured in such a way that they have a low rotational moveability in order to compensate for relative twisting between the stabilizer sections 3, 4.

[0050] The embodiment shown in FIG. 8 is characterized in that the pressure accumulator 34 of the control element 22 is provided as a separate element and is connected to the damping element 33. Furthermore, the control element 22 and the pressure accumulator 34 are arranged with axial overlap to the actuator 6. The housing 37 of the control element 22 is firmly connected to the actuator housing 7. The connecting lines 38, 39, and connectors 27, 28 respectively connect to a jacket portion of the actuator housing.

[0051] In the example shown in FIG. 9, the control element 22 comprises the damping unit 33 and the pressure accumulator 34 as a single unit. The control element 22 is longer than the actuator 6 and projects beyond it in the axial direction on one side. The connecting lines 38, 39, and respectively connectors 27, 28, connect to a jacket section of the actuator housing.

LIST OF REFERENCE SIGNS

[0052] 2 stabilizer assembly [0053] 3 first stabilizer section [0054] 4 second stabilizer section [0055] 5 spring element [0056] 6 actuator [0057] 7 actuator outer part [0058] 8 actuator inner part [0059] 9 intermediate element [0060] 10 bearing means [0061] 11 bearing means [0062] 12 sealing element [0063] 13 sealing element [0064] 14 connecting portion [0065] 15 connecting portion [0066] 16 first spring end [0067] 17 second spring end [0068] 18 outer engagement means [0069] 19 inner engagement means [0070] 20 first hydraulic chamber [0071] 21 second hydraulic chamber [0072] 22 control element [0073] 23 first end portion [0074] 24 inner seal [0075] 25 second end portion [0076] 26 outer seal [0077] 27 first connector [0078] 28 second connector [0079] 29 external helical toothing [0080] 30 inner helical toothing [0081] 31 hollow shaft toothing [0082] 32 shaft toothing [0083] 33 damping unit [0084] 34 pressure accumulator [0085] 35 switching valve [0086] 36 switching valve [0087] 37 control housing [0088] 38 line [0089] 39 line [0090] A axis [0091] R1 first direction [0092] R2 second direction