WHEEL SUSPENSION FOR A MOTOR VEHICLE, MOTOR VEHICLE AND METHOD FOR OPERATING A WHEEL SUSPENSION OF THIS KIND

Abstract

A wheel suspension for a motor vehicle having a body and at least one wheel and supportable via the wheel on a roadway, having at least one spring element having a progressive spring characteristic curve, via which the wheel is supportable in a spring-loaded manner on the body, wherein a vertical adjustment device is provided, by which the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

Claims

1. (canceled)

12. A wheel suspension for a motor vehicle comprising: a body and at least one wheel and supportable via the wheel on a roadway, having at least one spring element having a progressive spring characteristic curve, via which the wheel is supportable in a spring-loaded manner on the body, wherein the vertical adjustment device, by which the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

13. The wheel suspension as claimed in claim 12, wherein the spring element is formed from a fiber-reinforced plastic.

14. The wheel suspension as claimed in claim 13, wherein the fiber-reinforced plastic is a glass-fiber-reinforced plastic.

15. The wheel suspension as claimed in claim 12, wherein the spring element is designed as a meandering spring.

16. The wheel suspension as claimed in claim 12, wherein the vertical adjustment device has at least one adjustment element, the length of which is adjustable, whereby the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

17. The wheel suspension as claimed in claim 15, wherein the adjustment element is arranged, with respect to a force flow extending from the body via the spring element and the adjustment element to the wheel, between the body and the spring element or between the wheel and the spring element.

18. The wheel suspension as claimed in claim 12, wherein the vertical adjustment device is hydraulically and/or electrically operable, so that the body is hydraulically and/or electromechanically vertically adjustable.

19. The wheel suspension as claimed in claim 12, wherein the wheel suspension comprises the body and the wheel.

20. The wheel suspension as claimed in claim 12, wherein an electronic computing unit, which is designed to ascertain a load of the body, to control the vertical adjustment device in dependence on the ascertained load, and thus to effectuate a vertical adjustment of the body, while a change of the spring rate of the spring element does not occur.

21. A motor vehicle, comprising: a body, having at least one wheel, via which the body is supportable on a roadway for the motor vehicle, and having a wheel suspension, which has at least one spring element having a progressive spring characteristic curve, via which the wheel is supported in a spring-loaded manner on the body, wherein a vertical adjustment device, by which the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

22. A method for operating a wheel suspension of a motor vehicle comprising: a body and at least one wheel and is supportable via the wheels on a roadway, having at least one spring element having a progressive spring characteristic curve, via which the wheel is supported in a spring-loaded manner on the body, wherein the body is vertically adjusted by means of a vertical adjustment device of the motor vehicle, while a change of the spring rate of the spring element does not occur.

23. The wheel suspension as claimed in claim 13, wherein the spring element is designed as a meandering spring.

24. The wheel suspension as claimed in claim 14, wherein the spring element is designed as a meandering spring.

25. The wheel suspension as claimed in claim 13, wherein the vertical adjustment device has at least one adjustment element, the length of which is adjustable, whereby the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

26. The wheel suspension as claimed in claim 14, wherein the vertical adjustment device has at least one adjustment element, the length of which is adjustable, whereby the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

27. The wheel suspension as claimed in claim 15, wherein the vertical adjustment device has at least one adjustment element, the length of which is adjustable, whereby the body is vertically adjustable, while a change of the spring rate of the spring element does not occur.

28. The wheel suspension as claimed in claim 13, wherein the adjustment element is arranged, with respect to a force flow extending from the body via the spring element and the adjustment element to the wheel, between the body and the spring element or between the wheel and the spring element.

29. The wheel suspension as claimed in claim 14, wherein the adjustment element is arranged, with respect to a force flow extending from the body via the spring element and the adjustment element to the wheel, between the body and the spring element or between the wheel and the spring element.

30. The wheel suspension as claimed in claim 16, wherein the adjustment element is arranged, with respect to a force flow extending from the body via the spring element and the adjustment element to the wheel, between the body and the spring element or between the wheel and the spring element.

Description

[0038] The drawing shows, in the single FIGURE, a detail of a schematic and sectional front view of a motor vehicle according to the invention, which is designed as an automobile, in particular as a passenger vehicle.

[0039] The single FIGURE shows a detail in a schematic and sectional front view of a motor vehicle 10 designed as an automobile, in particular as a passenger vehicle, which has a body in the form of a self-supporting vehicle body 12. The motor vehicle 10 has at least one wheel 14, via which the motor vehicle 10 is supportable or supported downward in the vehicle vertical direction on a roadway 16 for the motor vehicle 10. In this case, the vehicle vertical direction is illustrated in the FIGURE by a double arrow 18. In particular, the motor vehicle 10 has multiple wheels, of which the wheel identified by 14 is recognizable in the FIGURE. The motor vehicle 10 preferably has at least or precisely four wheels, wherein the statements above and hereinafter on the wheel 14 can also be transferred readily to the other wheels. The motor vehicle 10 furthermore comprises a wheel suspesion 20, via which the wheel 14 is movably attached to the vehicle body 12. The wheel suspesion 20 permits relative movements between the wheel 14 and the vehicle body 12 at least extending in the vehicle vertical direction, so that the wheel 14 can move upward in relation to the vehicle body 12 in the vehicle vertical direction and can thus be compressed. In addition, for example, the wheel 14 can move downward in the vehicle vertical direction in relation to the vehicle body 12. For this purpose, the wheel suspesion 20 comprises a suspension rod arrangement 22, which has suspension rods 24, 26, and 28 also referred to as wheel suspension rods or guide suspension rods. The suspension rods 26 and 28 are designed, for example, as wishbones and are articulated on one side with the vehicle body 12 and are articulated on the other side with a wheel mount 30 of the wheel suspesion 20, wherein the wheel 14 is rotatably mounted on the wheel mount 30. The suspension rod 24 is coupled in an articulated manner on one side with the vehicle body 12 and is coupled in an articulated manner on the other side with the wheel mount 30. During retractions and extensions of the wheel 14 in relation to the vehicle body 12, the wheel mount 30 can pivot in relation to the suspension rods 24, 26, 28 and overall it is apparent that the wheel 14 is linked via the wheel suspesion 20 to the vehicle body 12.

[0040] The wheel suspesion 20 additionally comprises at least one spring element 32, via which the wheel 14 is supportable or supported in a spring-loaded manner on the vehicle body 12. The spring element 32 is designed as a mechanical spring element or as a mechanical spring, so that the spring element 32 is a spring different from a pneumatic spring and thus from an air spring. In particular, the spring element 32 is designed as a coiled spring, in particular as a coiled compression spring.

[0041] It has been shown to be particularly advantageous if the spring element 32 is designed as a meandering spring. Since the spring element 32 is designed as a mechanical spring element, the spring element 32 is formed from a solid material, i.e., from a material which exists in the solid phase at a temperature of 25 C. The material from which the spring element 32 is formed is also referred to as a substance, wherein the spring element 32 is intrinsically rigid or dimensionally stable and elastically deformable at the same time.

[0042] The spring element 32 designed as a mechanical spring or as a mechanical spring element is supported on one side at least indirectly on the wheel 14 and on the other side at least indirectly on the vehicle body 12. On the wheel side, the spring element 32 is supported via the suspension arm arrangement 22 and via the suspension arm 24 and the wheel mount 30 on the wheel 14. If a retraction of the wheel 14 occurs, which moves in the context of the retraction upward in relation to the body 12 in the vehicle vertical direction, the spring element 32 is thus tensioned, in particular pressed together or compressed. In this way, the spring element 32 provides a spring force, by means of which the wheel 14 can be moved back downward in the vehicle vertical direction in relation to the body 12, whereby the wheel 14 extends, for example. To damp an oscillation of such retraction and extension movements of the wheel 14, for example, a shock absorber (not shown in the FIGURE) is provided, by means of which following relative movements in the vehicle vertical direction between the wheel 14 and the vehicle body 12 are to be damped, i.e., are damped. In particular, the retractions and extensions of the wheel 14 in relation to the vehicle body 12 can be damped by means of the shock absorber. The spring element 32 has a progressive spring characteristic curve, so that the spring element 32 is designed as a progressive suspension spring or progressive body spring. In other words, the spring element 32 has a progressive characteristic. The preferably hydraulic shock absorber is arranged or connected in parallel to the spring element 32 and is coupled on one side at least indirectly to the vehicle body 12 and on the other side indirectly to the wheel 14.

[0043] To be able to implement a particularly high level of comfort and a particularly advantageous driving behavior of the motor vehicle 10, the wheel suspesion 20 and thus the motor vehicle 10 comprises a vertical adjustment device 34, by means of which the vehicle body 12 is vertically adjustable, while a change of the spring rate of the spring element 32 does not occur. The feature that the body 12 is vertically adjustable by means of the vertical adjustment device 34, in particular in relation to the roadway 16, is to be understood to mean that the vehicle body 12 can be moved by means of the vertical adjustment device 34 in the vehicle vertical direction in relation to the roadway 16, while the vehicle body 12 is supported via the wheel 14 on the roadway 16.

[0044] The FIGURE shows the spring element 32, for example, in a first state, in which the vehicle body 12 or the motor vehicle 10 as a whole is unloaded. If the vehicle body 12 is not loaded, so that the mass of the motor vehicle 10 as a whole increases, the vehicle body 12 thus sinks in the direction of the roadway 16 if initially a vertical adjustment of the vehicle body 12 does not occur. Due to this sinking of the vehicle body 12, the vehicle body 12 moves downward in the vehicle vertical direction in the direction of the roadway 16, whereby the spring element 32 is compressed and thus tensioned starting from the first state. The spring element 32 thus enters a second state, in which the spring element 32 is more strongly compressed and thus more strongly tensioned in relation to the first state. Since the spring element 32 has a progressive spring characteristic curve, the spring rate of the spring element 32 is higher or greater in the second state than in the first state.

[0045] In other words, the spring rate of the spring element 32 has a first value in the first state and a second value greater than the first value in the second state, wherein the respective value is a positive greater number in relation to zero or a positive greater value in relation to zero.

[0046] To now maintain the greater spring rate, and at the same time to implement a sufficient ground clearance, however, i.e., to implement a sufficient distance extending in the vehicle vertical direction between the vehicle body 12 and the roadway 16, the vehicle body 12 is moved upward away from the roadway 16 in the vehicle vertical direction by means of the vertical adjustment device 34, while the second state of the spring element 32 and thus the spring rate greater than the first state is maintained, i.e., during this a change of the spring rate of the spring element 32 does not occur.

[0047] This takes place in the exemplary embodiment illustrated in the FIGURE in that the vertical adjustment device 34 has at least one adjustment element 36. The adjustment element 36 is in particular coupled in an articulated manner on one side at least indirectly, in particular directly, with the spring element 32, in particular with its one end 38. On the other side, the adjustment element 36 is in particular coupled in an articulated manner at least indirectly, in particular directly, with the vehicle body 12. The adjustment element 36 has a first adjustment part 40 and a second adjustment part 42, wherein the adjustment part 40 is coupled with the spring element 32 and the adjustment part 42 is coupled with the vehicle body 12. The adjustment parts 40 and 42 are translationally movable in relation to one another along a movement direction illustrated by a double arrow 44 in the FIGURE, wherein the movement direction extends obliquely or in parallel to the vehicle vertical direction.

[0048] The vertical adjustment device 34, in particular the adjustment element 36, has a drive 46, by means of which the adjustment parts 40 and 42 are translationally movable in relation to one another along the movement direction. If, for example, by means of the drive 46, one of the adjustment parts 40 and 42 is translationally moved in relation to the respective other adjustment part 42 or 40, respectively, in a first direction coinciding with the movement direction, thus, for example, the vehicle body 12 is moved upward in the vehicle direction away from the roadway 16, i.e., raised, while a change of the spring rate of the spring element 32 does not occur. If, for example, by means of the drive 46, the one adjustment part 40 or 42 is translationally moved in a direction opposite to the first direction and thus coinciding with the movement direction in relation to the respective other adjustment part 42 or 40, respectively, thus, for example, the body 12 is moved downward in the vehicle vertical direction in the direction of the roadway 16 and thus lowered, while a change of the spring rate of the spring element 32 does not occur. A change of the spring rate of the spring element 32 does not occur during the raising and lowering of the 07780687US vehicle body 12 in particular in that during the lowering or raising of the vehicle body 12, a length change of the spring element 32 does not occur.

[0049] This is implemented in that the adjustment element 36 is arranged, with respect to a force flow extending from the vehicle body 12 via the adjustment element 36 and the spring element 32 to the wheel 14 and via this to the roadway 16, between the vehicle body 12 and the spring element 32, so that the adjustment element 36 and the spring element 32 are arranged or connected in series to one another in the described force flow. Alternatively thereto, it would be conceivable that the adjustment element 36 is arranged between the spring element 32 and the wheel 14, so that then the adjustment element 36 and the spring element 32 are also arranged or connected in series to one another in the force flow. The drive 46 is preferably a hydraulic drive, so that the adjustment parts 40 and 42 are translationally movable in relation to one another hydraulically. Furthermore, it can preferably be provided that the drive 46 is an electric drive, so that the drive 46 is designed, for example, as an electric motor. The adjustment parts 40 and 42 are thus translationally movable in relation to one another electrically, for example.

[0050] To be able to implement a particularly high level of robustness of the spring element 32, in particular with respect to corrosion, it is preferably provided that the spring element 32 is formed from a glass-fiber-reinforced plastic and thus from a fiber-reinforced plastic.

[0051] One of the adjustment parts 40 and 42 has, for example, a piston rod and a piston connected thereto, wherein the respective other adjustment part 42 or 40, respectively, has a cylinder, in which the piston is accommodated so it is translationally movable. The cylinder and the piston form a chamber, which can be supplied, for example, with an operating medium, in particular with a hydraulic liquid. For example, if hydraulic liquid is introduced into the chamber, for example, the piston and the piston rod are thus extended out of the cylinder, whereby a length enlargement or length increase of the adjustment element 36 is effectuated. The vehicle body 12 is raised, for example, by such a length enlargement of the adjustment element 36. If at least a part of the hydraulic liquid initially accommodated in the chamber is discharged from the chamber, the piston and the piston rod are thus retracted into the cylinder, whereby a length shortening or length reduction of the adjustment element 36 is effectuated. The vehicle body 12 is lowered by such a length shortening. The adjustment element 36 thus has, for example, a hydraulic cylinder, by means of which the vehicle body 12 is hydraulically vertically adjustable.

[0052] To implement an electrical or electromechanical vertical adjustment of the vehicle body 12, for example, one of the adjustment parts 40 and 42 is designed as a threaded spindle and the respective other adjustment part 42 or 40, respectively, is designed as a nut, which is screwed via respective thread of the nut and the threaded spindle onto the threaded spindle. In the exemplary embodiment illustrated in the FIGURE, for example, the one adjustment part is the adjustment part 40, which is designed as a threaded spindle or has the piston rod and the piston connected thereto. The other adjustment part is, for example, the adjustment part 42, which is thus designed as the mentioned cylinder or as the nut, respectively.

[0053] By means of the drive 46, the threaded spindle and the nut can be rotated in relation to one another around the rotational axis, wherein such relative rotations between the threaded spindle and the threaded nut are converted by means of the thread into translational movements between the nut and the threaded spindle. In the context of such a translational relative movement between the nut and the threaded spindle, for example, the nut is translationally moved along the threaded spindle in relation to the threaded spindle. Depending on the direction in which the threaded spindle and the nut are rotated in relation to one another, the vehicle body 12 is then raised or lowered.

[0054] To implement a particularly high level of driving comfort, the motor vehicle 10, in particular the wheel suspesion 20, comprises an electronic computing unit 48 schematically shown separately in the FIGURE. In the scope of a method for operating the wheel suspesion 20, for example, a load of the vehicle body 12 is ascertained by means of the electronic computing unit 48. Alternatively or additionally, a retraction state of the wheel 14 in relation to the vehicle body 12 and/or a distance extending in the vehicle vertical direction between the vehicle body 12 and the roadway 16 is ascertained by means of the electronic computing unit 48. In dependence on the ascertained load and/or in dependence on ascertained retraction and/or in dependence on the ascertained distance, the electronic computing unit 48 controls the drive 46, whereby a vertical adjustment of the vehicle body 12 is effectuated, while a change of the spring rate of the spring element 32 does not occur.

[0055] In this way, independently of the load, the same ride height and thus the same ground clearance of the motor vehicle 10 can always be implemented, without a person having to be active for this purpose. Since the vertical adjustment takes place without change of the spring rate of the spring element 32, for example, in the loaded state, the greater spring rate of the spring element 32 in relation to the unloaded state can be maintained, so that particularly advantageous driving behavior and a particularly high level of driving comfort can be ensured.