VEHICLE AND A SUSPENSION SYSTEM FOR THE VEHICLE

Abstract

Suspension system (12) for a vehicle (10), wherein the suspension system (12) comprises: a steering knuckle (44); a transverse arm (56) coupled to the steering knuckle (44), wherein the transverse arm (56) has a proximal end (58) with a first arm segment (60) and a second arm segment (62), each extending outwards from the proximal end (58) to a respective first and second distal end (64, 66) to define a space (68) between the first and second arm segment (60, 62); characterized by: a pre-tensioning device (70) which is at least partially arranged in the space (68) between the first and the second arm segment (60, 62), wherein the pre-tensioning device (70) is coupled to the first and / or the second distal end (64, 66) of the first and / or the second arm segment (60, 62) such that actuation of the pre-tensioning device (70) provides a first reaction force which counteracts a downward load acting on the control arm (56), wherein the first reaction force is substantially proportional to the downward load in order to substantially maintain a position of the steering knuckle (44).

Description

TECHNICAL FIELD

[0001] The present invention relates to a suspension system according to the preamble of claim 1. BACKGROUND

[0002] Such a suspension system is known from the generic document US 2 071 577 A. Essentially comparable suspension systems are disclosed in the documents US 2 998 241 A, US 3 027 177 A, US 4 168 075 A, US 4 540 10 197 A, US 6 182 979 B1, and US 8 454 041 B2.

[0003] Many vehicles have a suspension system.

[0004] When a vehicle travels over a bump or a pothole in a road, the suspension system can control various forces between the vehicle's sprung mass and the road, creating a smooth ride. For example, some passenger cars and trucks are equipped with a suspension system that includes a strut with a coil spring and a piston-cylinder assembly. The coil spring surrounds the piston-cylinder assembly, and the coil spring and piston-cylinder assembly interact to generate forces that dampen the movement of the sprung mass.

[0005] Additionally, some truck designs include a suspension system with a torsion bar that acts as a spring. The torsion bar is used instead of the coil spring mentioned above. The torsion bar is attached to an outer side surface of a lower control arm, and a steering knuckle is coupled to the lower control arm. The torsion bar is twisted to exert a moment force, which acts as a vertical force on the lower control arm to keep the truck's sprung mass suspended. A large space is used to provide space for the torsion bar to attach to the lower control arm on the outer side surface.

[0006] Additionally, some sports cars were designed with a spoiler on a trunk of the car to increase a downward force exerted on the car's sprung mass. The car's suspension system may include the strut mentioned above. The downward force exerted on the car's sprung mass due to the spoiler may cause the car's sprung mass to move downward toward the road. To counteract this downward force, a hydraulic actuator may be operatively coupled to the strut to adjust the seat height of the strut's coil spring. Adjusting the seat height changes the amount of compression of the coil spring, which counteracts the downward force.Another alternative to counteract this downward force is the use of a lift spring that is functionally coupled to the struts of opposite wheels and, in this configuration, can counteract the downward force when both sides of the vehicle experience a simultaneous vertical deflection.

[0007] The invention is based on the object of specifying a suspension system for a vehicle with which influences on the driving dynamics resulting from downward forces acting on the wishbones can be reduced.

[0008] This object is achieved with a suspension system having the features of claim 1. SUMMARY

[0009] The present invention provides a suspension system for a vehicle. The suspension system includes a steering knuckle and a control arm coupled to the steering knuckle. The control arm has a proximal end with a first arm segment and a second arm segment, each extending outwardly away from the proximal end to a respective first and second distal end to define a space between the first and second arm segments. The suspension system also includes a preload device at least partially disposed within the space between the first and second arm segments. The preload device is coupled to at least one of the first and second distal ends of the first and second arm segments, respectively, such that actuation of the preload device provides a first reaction force that counteracts a downward load acting on the control arm.The first reaction force is substantially proportional to the downward load to maintain a substantially upright position of the steering knuckle.

[0010] The present invention also provides a vehicle having a structure and a suspension system supporting the structure. The suspension system includes a steering knuckle and a control arm coupled to the steering knuckle. The control arm has a proximal end with a first arm segment and a second arm segment, each extending outwardly away from each other from the proximal end to respective first and second distal ends to define a space between the first and second arm segments. The suspension system also includes a preload device at least partially disposed within the space between the first and second arm segments. The preload device is coupled to at least one of the first and second distal ends of the first and second arm segments, respectively, such that actuation of the preload device provides a first reaction force that counteracts a downward load applied to the structure.The first reaction force is substantially proportional to the downward load to substantially maintain a position of the structure relative to the steering knuckle.

[0011] The detailed description and the drawings or figures are intended to support and describe the invention. While some of the best modes and other embodiments for carrying out the claims are described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic perspective view of a vehicle with a spoiler retracted. Fig. Figure 2 is a schematic, fragmentary perspective view of the vehicle with the spoiler extended. Fig. Figure 3 is a schematic cross-sectional view of a suspension system. Fig. Figure 4 is a schematic perspective view of the suspension system. Fig. Figure 5 is a schematic, fragmentary side view of the suspension system. Fig. 6 is a schematic perspective view of the suspension system having a preload device for one wheel of the vehicle and another preload device for another wheel of the vehicle. DETAILED DESCRIPTION

[0012] Those skilled in the art will recognize that terms such as "above," "below," "upward," "upward," "downward," "downward," "at the top," "at the bottom," "left," "right," etc., are used to describe the figures. In addition, the term "substantially" may denote a slight inaccuracy or slight variation of a condition, quantity, value, or dimension, etc.

[0013] Referring to the figures, wherein like reference characters indicate like or corresponding parts throughout the several views, a vehicle 10 is generally shown in Fig. 1, and a suspension system 12 for the vehicle 10 is shown generally in Fig. 3-6. The vehicle 10 may be a motor vehicle, such as a passenger car, a sports car, a truck, etc. Furthermore, the vehicle 10 may be a hybrid vehicle that uses an internal combustion engine and one or more motor-generators. Additionally, the vehicle 10 may be an electric vehicle that uses one or more motor-generators and forgoes the internal combustion engine. As another example, the vehicle 10 may be a vehicle that uses the internal combustion engine and forgoes the motor-generators. It should be understood that the vehicle 10 may alternatively not be a motor vehicle.

[0014] How best in Fig. 1, Fig. 2 and Fig. 4, the vehicle 10 may include a structure 14. Generally, the suspension system 12 supports the structure 14, and the structure 14 is spaced from a road 16 or the ground. When the vehicle 10 travels over a bump or a hole in the road 16, the suspension system 12 may dampen the movement of the structure 14 toward and away from the road 16, thereby providing a smooth ride. In other words, the suspension system 12 may dampen the vertical movement of the structure 14 relative to the road 16. The structure 14 may therefore be one or more of: a chassis, a support structure, a frame, a subframe, a body, a strut, a panel, a skin, a beam, etc.Simply stated, the structure 14 may be any sprung mass component of the vehicle 10, including, for example, the body, frame, subframe, chassis, outer skin, or any load-bearing component supported by the suspension system 12. It will be appreciated that the structure 14 may be any suitable configuration.

[0015] The vehicle 10 can optionally have a spoiler 18 (see Fig. 1 and Fig. 2) or have a tail fin that can be retracted or extended to change a downward load (the downward load is in Fig. 1, Fig. 2 and Fig. 4 with the arrow 20) exerted on the structure 14 or the sprung mass of the vehicle 10. The downward load may be a downward force exerted on the structure 14. The spoiler 18 is exposed on the outside of the vehicle 10 and may, for example, be movably coupled to a trunk 22 of the vehicle 10. The spoiler 18 is in Fig. 1 and in Fig. 2 extended. In the retracted position, an outer surface 24 of the spoiler 18 and an outer surface 26 of the outer skin are substantially flush with each other, and therefore, the extended position of the spoiler 18 can be any position other than the retracted position. In other words, in the extended position of the spoiler 18, the outer surface 24 of the spoiler 18 is not substantially flush with the outer surface 26 of the outer skin.

[0016] The spoiler 18 can be adjusted automatically or manually. As shown in Fig. For example, as shown in Figure 2, a first motor 28 may be coupled to the spoiler 18 to move the spoiler 18 to a desired position, namely the extended or retracted position. The first motor 28 may be an electromechanical motor, an electric motor, or any other suitable mechanism for moving the spoiler 18. It will be appreciated that a position sensor 30 may be coupled to the spoiler 18 or a portion of the first motor 28 to detect the position of the spoiler 18.

[0017] When the vehicle 10 is moving, the aerodynamics create the downward load (arrow 20) exerted on the vehicle 10, and more specifically, on the structure 14 or sprung mass. Therefore, extending or retracting the spoiler 18 changes the aerodynamics of the vehicle 10, and thus changes the downward load exerted on the structure 14. Generally, when the spoiler 18 is extended, a first downward load is exerted on the structure 14, and when the spoiler 18 is retracted, a second downward load is exerted on the structure 14, where the first downward load is greater than the second downward load. For example, by increasing the downward load exerted on the structure 14 or the sprung mass, the cornering of the vehicle 10 may be improved compared to when a smaller downward load is exerted on the structure 14 or the sprung mass, respectively.The suspension system 12 discussed herein can counteract the downward load applied to the structure 14 to facilitate high-speed cornering. Specifically, the suspension system 12 can be actively adjusted to counteract the downward load applied to the structure 14. It will be appreciated that when the spoiler 18 is used, the spoiler 18 can be in any suitable position and configuration.

[0018] How best in Fig. 1 and Fig. 6, the vehicle 10 may also include a first wheel assembly 32 and, in certain embodiments, a second wheel assembly 34. The wheel assemblies 32, 34 rotate over the road 16 and are coupled to the suspension system 12. The wheel assemblies 32, 34 are disposed on opposite sides of the vehicle 10, such as on the left and right sides of the vehicle 10. For example, the first wheel assembly 32 may be disposed along a driver's side 36 of the vehicle 10, and the second wheel assembly 34 may be disposed along a passenger side 38 of the vehicle 10. Furthermore, the first and second wheel assemblies 32, 34 may be provided for a rear 40 of the vehicle 10, a front 142 of the vehicle 10, or any other suitable location on the vehicle 10.If the first and second wheel assemblies 32, 34 are provided for the rear 40 of the vehicle 10, the wheel assemblies 32, 34 may be referred to as rear wheel assemblies 32, 34.

[0019] The first and second wheel assemblies 32, 34 each include a tire 42 (as shown in Fig. 1 in solid lines and in Fig. 4 and Fig. 6 in dashed lines) and a hub supporting the corresponding tires 42. The download discussed above is a downward force applied to the structure 14, which is transmitted to the tires 42 and contributes to creating grip between the tires 42 and the road 16. For example, as the downward load applied to the structure 14 is increased, the downward force transmitted to or acting on the tires 42 increases, thereby creating greater grip between the tires 42 and the road 16.

[0020] With reference to Fig. 3 and Fig. 4, the suspension system 12 includes a steering knuckle 44. The steering knuckle 44 is coupled to the first wheel assembly 32. Specifically, the steering knuckle 44 is coupled to the hub of the first wheel assembly 32 such that the first wheel assembly 32 can rotate relative to the steering knuckle 44. The downward load exerted on the structure 14 is transferred to or acts on the steering knuckle 44 substantially along an axis 46. The axis 46 extends transversely to the road 16.

[0021] When the first wheel assembly 32 includes the tire 42, which is rotated to steer the vehicle 10, the steering knuckle 44 is pivotable with the tire 42. When the steering knuckle 44 is pivoted, the first wheel assembly 32 rotates, for example, to the left or to the right, thereby steering the vehicle 10 to the left or right. When the first wheel assembly 32 includes the tire 42, which is not rotated to steer the vehicle 10, the steering knuckle 44 is not pivotable with the tire 42. When the steering knuckle 44 does not pivot, the first wheel assembly 32 does not rotate, for example, to the left or right, to steer the vehicle 10.

[0022] How best in Fig. 3 and Fig. 4, the steering knuckle 44 may include an upper segment 48 and a lower segment 50 disposed below the upper segment 48 relative to the axle 46. The steering knuckle 44 may also include a first side 52 and a second side 54 spaced apart from each other transversely of the axle 46. Generally, the first side 52 faces inwardly of the second wheel assembly 34, and the second side 54 faces outwardly of the second wheel assembly 34. The upper and lower segments 48, 50 may each include a portion of the first and second sides 52, 54.

[0023] With further reference to Fig. 3 and Fig. 4, the suspension system 12 further includes a control arm 56 coupled to the steering knuckle 44. Furthermore, the control arm 56 is also coupled to the structure 14. Therefore, the control arm 56 couples the steering knuckle 44 to the structure 14. The downward load applied to the structure 14 is transferred to or acts upon the control arm 56 and subsequently transferred to or acts upon the steering knuckle and the first wheel assembly 32.

[0024] With further reference to Fig. 3 and Fig. 4, the control arm 56 again has a proximal end 58 with a first arm segment 60 and a second arm segment 62, each extending outwardly away from the proximal end 58 to a respective first and second distal end 64, 66 to define a space 68 between the first and second arm segments 60, 62. Specifically, the proximal end 58 of the control arm 56 is coupled to the upper segment 48 of the steering knuckle 44. Therefore, the proximal end 58 of the control arm 56 couples the steering knuckle 44 to the structure 14. For example, a ball joint may couple the steering knuckle 44 to the proximal end 58 of the control arm 56.

[0025] To Fig. 4-6, the suspension system 12 also includes a preload device 70 disposed at least partially within the space 68 between the first and second arm segments 60, 62. The installation space is reduced by disposing the preload device 70 at least partially within the space 68. The preload device 70 may be provided for the suspension system 12 of the rear 40 of the vehicle 10 or the front 142 of the vehicle 10.

[0026] The pretensioning device 70 provides a reaction force (the reaction force is in Fig. 3 and Fig. 5 with the arrow 72) that counteracts the downward load (arrow 20). The pretensioner 70 is coupled to the first and / or second distal ends 64, 66 of the first and second arm segments 60, 62, respectively, such that actuation of the pretensioner 70 provides a first reaction force that counteracts the downward load acting on the control arm 56. The first reaction force is substantially proportional to the downward load to substantially maintain a position of the steering knuckle 44. As discussed above, the downward load is transmitted to or acts on the control arm 56, and is subsequently transmitted to or acts on the steering knuckle 44. More specifically, the pretensioner 70 is coupled to the first and / or second distal ends 64, 66 of the first and second arm segments 60, 62, respectively.second arm segment 60, 62 such that actuation of the pretensioner 70 provides the first reaction force that counteracts the downward load exerted on the structure 14. The first reaction force is substantially proportional to the downward load to maintain a vertical position of the structure 14 relative to the steering knuckle 44. By counteracting the first downward load, therefore, the structure 14 is enabled to substantially maintain its vertical position relative to the road 16. Thus, the suspension system 12 can be actively adjusted to counteract the downward load acting on the structure 14 to substantially maintain the suspension travel and thereby the vertical position of the structure 14 relative to the road 16. Simply stated, the reaction force is substantially opposite the downward load. The vertical position of the structure 14 can be the elevation of the structure 14 with respect to the road 16.Thus, the height of structure 14 relative to road 16 may be substantially maintained or changed (as discussed further below). In other words, the vertical position may be the position of structure 14 spaced from road 16 or a component of vehicle 10, such as steering knuckle 44, substantially along axis 46.

[0027] The phrase "and / or" should be construed to include a non-exclusive logical "or," i.e., at least one of the first distal end 64 or the second distal end 66. Therefore, in certain embodiments, the biasing device 70 is coupled to the first distal end 64 of the first arm segment 60 or to the second distal end 66 of the second arm segment 62. In other embodiments, the biasing device 70 is coupled to both the first and second distal ends 64, 66 of the first and second arm segments 60, 62, respectively.

[0028] How best in Fig. 3-5, the biasing device 70 may be disposed between the first and second distal ends 64, 66 of the first and second arm segments 60, 62, respectively. Furthermore, the first and second distal ends 64, 66 may be spaced apart from one another along a longitudinal axis 74. As further discussed below, a portion of the biasing device 70 may extend beyond the first and / or second distal ends 64, 66 of the first and second arm segments 60, 62, respectively. For example, as shown in Fig. 5, a portion of the biasing device 70 extends beyond the first distal end 64 of the first arm segment 60 and away from the second distal end 66 of the second arm segment 62. As another example, a portion of the biasing device 70 may extend beyond the second distal end 66 of the second arm segment 62 and away from the first distal end 64 of the first arm segment 60. The interpretation of the phrase "and / or" is explained above and will not be discussed again.

[0029] Generally, the control arm 56 is rotatable about the longitudinal axis 74. Therefore, as the control arm 56 rotates about the longitudinal axis 74, the structure 14 can accordingly move upwardly or downwardly relative to the road 16 or generally along the axis 46. Furthermore, as the control arm 56 rotates about the longitudinal axis 74, the control arm 56 moves relative to the steering knuckle 44.

[0030] The preloader 70 provides for active suspension adjustment. For example, when lane keeping and / or high-speed or cornering are desired, the spoiler 18 is moved from the retracted position to the extended position, and simultaneously or thereafter, the preloader 70 is actuated to counteract the increased downward load applied to the structure 14 to substantially maintain the vertical position of the structure 14 relative to the road 16. As another example, when good roadholding and / or low-speed driving are desired, the spoiler 18 is moved from the extended position back to the retracted position, and simultaneously or thereafter, the preloader 70 is actuated to change the reaction force that counteracts the downward force, thereby allowing the structure 14 to change its vertical position.It will be appreciated that when the pretensioner 70 and the spoiler 18 are actuated sequentially, the pretensioner 70 may be actuated before or after the spoiler 18. Therefore, the downward load and reaction force may continuously change depending on the desired operation of the vehicle 10.

[0031] Specifically, the pretensioner 70 is operable in a first mode to provide the first reaction force substantially proportional to the downward load. The pretensioner 70 is also operable in a second mode to provide a second reaction force that opposes the downward load acting on the control arm 56 such that the second reaction force is different from the downward load, thereby allowing the control arm 56 to selectively rotate about the longitudinal axis 74 to change the position of the control arm 56 relative to the steering knuckle 44. More specifically, the second mode provides the second reaction force that opposes the downward load applied to the structure 14. Therefore, the second reaction force is different from the downward load, thereby allowing the control arm 56 to selectively rotate about the longitudinal axis 74 to change the vertical position of the structure 14 relative to the steering knuckle 44.The preload device 70 can be operated in both the first and second modes. When the preload device 70 is operated in the second mode, the preload device 70 is rotated to change the reaction force that counteracts the downward load.

[0032] The first reaction force and the second reaction force may have any suitable amounts or values. The first and second reaction forces may change depending on whether the vehicle 10 is operating in the first or second mode. Furthermore, the first and second reaction forces may change depending on the downward load applied to the structure 14. The downward load may change due to the speed of the vehicle 10, the position of the spoiler 18, the amount of weight being in or removed from the vehicle 10, etc. Therefore, the first reaction force may be greater than, less than, or equal to the second reaction force depending on the amount of the downward load and / or the mode. The change in the reaction force allows the structure 14 to be moved closer to the road 16, i.e.that the distance between the structure 14 and the road 16 is decreased, or moved further away from the road 16, that is, that the distance between the structure 14 and the road 16 is increased. For example, if the reaction force is less than the downward load, the structure 14 may be moved closer to the road 16. As another example, if the reaction force is greater than the downward load, the structure 14 may be moved away from the road 16. Furthermore, if the downward load changes due to changes in the speed of the vehicle 10 or the position of the spoiler 18, the first reaction force may be changed accordingly to substantially maintain the vertical position of the structure 14 relative to the road 16, or the second reaction force may be changed accordingly to allow the vertical position of the structure 14 relative to the road 16 to be changed.Therefore, the downward load and reaction force can change continuously.

[0033] With reference to Fig. 3 and Fig. 4, the pretensioner 70 may include a torsion bar 76 disposed within the space 68 and extending along the longitudinal axis 74. Positioning the torsion bar 76 within the space 68 between the first and second distal ends 64, 66 creates a compact package for the pretensioner 70. In certain embodiments, the torsion bar 76 extends concentrically or coaxially with the longitudinal axis 74. The torsion bar 76 may include a first end portion 78 and a second end portion 80 spaced apart from each other along the longitudinal axis 74. One of the first and second end portions 78, 80 of the torsion bar 76 is fixed, while the other of the first and second end portions 78, 80 is rotatable to exert a torsional force on the torsion bar 76. Simply put, a torque can be applied to the torsion bar 76 to provide the initial reaction force that counteracts the downward load.Therefore, a torque may be applied to the torsion bar 76 in the first mode, and the torque applied to the torsion bar 76 may be varied in the second mode. Thus, a torque may be applied to the torsion bar 76 in both the first and second modes, and it may be varied depending on the amount of downward load and / or the mode. The torsional force is transmitted to or acts on the control arm 56 as the reaction force that counteracts the downward load. The reaction force may be directed substantially upward through the control arm 56 and the steering knuckle 44 to counteract the downward load that is directed substantially downward through the control arm 56 and the steering knuckle 44. Generally, the preloader 70 acts or functions as an adjustable load spring.

[0034] With further reference to Fig. 3 and Fig. 4, the pretensioner 70 may additionally include a housing 82 attached to the first or second distal end 64, 66 of the first or second arm segments 60, 62, respectively, to couple the pretensioner 70 to the control arm 56. In certain embodiments, the housing 82 is therefore attached to the first distal end 64 of the first arm segment 60 or to the second distal end 66 of the second arm segment 62. In other embodiments, the housing 82 is attached to both the first and second distal ends 64, 66 of the first or second arm segments 60, 62, respectively, to couple the pretensioner 70 to the control arm 56. The housing 82 is attached to the control arm 56 such that the reaction force is transmitted through the housing 82 to or acts on the control arm 56.

[0035] The housing 82 can be rotatable about the longitudinal axis 74. Thus, the housing 82 is attached to the first or second distal end 64, 66, or both, such that the control arm 56 and the housing 82 are selectively rotatable as a unit about the longitudinal axis 74. Simply stated, the housing 82 is attached to the control arm 56 such that the housing 82 and the control arm 56 can rotate as a unit or together about the longitudinal axis 74. Therefore, for example, the biasing device 70 can be coupled to both the first and second distal ends 64, 66 of the first and second arm segments 60, 62, respectively, such that the control arm 56 and the housing 82 are selectively rotatable as a unit.

[0036] With reference to Fig. 3-5, in certain embodiments, the housing 82 may have a first end 84 and a second end 86 spaced apart along the longitudinal axis 74. The first and / or second distal ends 64, 66 of the first and second arm segments 60, 62, respectively, may be attached to the housing 82. In certain embodiments, the first distal end 64 is attached adjacent to the first end 84 of the housing 82, and / or the second distal end 66 is attached adjacent to the second end 86 of the housing 82. Furthermore, in certain embodiments, the first end 84 of the housing 82 is located beyond the first distal end 64 of the first arm segment 60 from the space 68, and / or the second end 86 of the housing 82 is located beyond the second distal end 66 of the second arm segment 62 from the space 68.Simply put, the first and second ends 84, 86 of the housing 82 are spaced apart from the space 68 between the first and second arm segments 60, 62. In other words, the first and second ends 84, 86 of the housing 82 are not located in the space 68 between the first and second arm segments 60, 62.

[0037] With further reference to Fig. 3-5, the suspension system 12 may also include at least one bushing or at least one bearing 88 coupled to the housing 82. The bushing or bearing 88 may minimize friction between the housing 82 and the bushing during rotation of the housing 82 about the longitudinal axis 74. In certain embodiments, multiple bushings or bearings 88 may be used. Generally, the bushings or bearings 88 surround the exterior of the housing 82 and may support the housing 82. One bushing or bearing 88 may be disposed adjacent the first end 84 of the housing 82, and another bushing or bearing 88 may be disposed adjacent the second end 86 of the housing 82. Thus, in certain embodiments, the bushings or bearings 88 are disposed outside the space 68 between the first and second arm segments 60, 62.In other words, the bushings or bearings 88 are spaced from the space 68 between the first and second arm segments 60, 62. Therefore, in certain embodiments, one bushing or bearing 88 is disposed between the first end 84 of the housing 82 and the first distal end 64 of the first arm segment 60, and another bushing or bearing 88 is disposed between the second end 86 of the housing 82 and the second distal end 66 of the second arm segment 62. Simply stated, the bushings or bearings 88 may be disposed outside of the first and second arm segments 60, 62. It will be appreciated that the bushing(s) or bearing(s) 88 may be located in any suitable position.

[0038] Furthermore, the bushings are attached to the structure 14. For example, the bushings may be disposed between a pair of ribs 90 on the frame. Specifically, the bushings may include a pair of feet 92 wedged between the pair of ribs 90 to secure the bushings to the structure 14. It will be appreciated that the bushings may be attached or mounted to the structure 14 in any position, configuration, and / or by any method. The feet 92 may transfer the downward load exerted on the structure 14 to the housing 82, the control arm 56, the steering knuckle 44, and therefore to the first wheel assembly 32. Furthermore, the reaction force is transferred from the housing 82 and the control arm 56 to counteract the downward load.Simply put, the downward load exerted on the structure 14 acts on or is transmitted to the bushings, and this downward load acts on or is transmitted to the housing 82 and thus to the control arm 56 through the bushings. The bushings / bearings may be pillow block bushings or pillow block bearings. It should be understood that the bushing(s) or bearing(s) 88 may be any suitable configuration.

[0039] How best in Fig. 3, the torsion bar 76 may be at least partially disposed within the interior of the housing 82. For example, the housing 82 may have a first length 94, and the torsion bar 76 may have a second length 96 that is greater than the first length 94 such that the torsion bar 76 extends outside the housing 82. Generally, a portion of the second length 96 of the torsion bar 76 may be located within the housing 82, and another portion of the torsion bar 76 may extend outside the housing 82. It will be appreciated that the housing 82 and the torsion bar 76 may have any suitable length. Furthermore, the torsion bar 76 may have any suitable thickness. Additionally, a portion of the torsion bar 76 may extend beyond the first and / or second distal ends 64, 66 of the first and second arm segments 60, 62, respectively. As shown in Fig. 5, a portion of the torsion bar 76 extends beyond the first distal end 64 of the first arm segment 60 and away from the second distal end 66 of the second arm segment 62. As another example, a portion of the torsion bar 76 may extend beyond the second distal end 66 of the second arm segment 62 and away from the first distal end 64 of the first arm segment 60. In one configuration, approximately 20% of the second length 96 of the torsion bar 76 extends beyond the second distal end 66 of the second arm segment 62 and away from the first distal end 64 of the first arm segment 60. It will be appreciated that the torsion bar 76 may be located at any suitable position relative to the control arm 56.

[0040] In certain embodiments, the second end portion 80 (of the torsion bar 76) is fixed to the housing 82, and the first end portion 78 is disposed outside the housing 82. Specifically, the second end portion 80 of the torsion bar 76 may be fixed to the housing 82, and more specifically, to the second end 86 of the housing 82. The fixing of the second end portion 80 to the housing 82 provides the fixed point with respect to which the torsion bar 76 can be twisted or rotated. Therefore, the rotation of the torsion bar 76 provides the torsional force that is transmitted to, or acts as the reaction force on, the control arm 56 that counteracts the downward load. Specifically, the torque applied to the torsion bar 76 by the rotation or twisting of the torsion bar 76 creates a moment (a torsional force) that acts on the housing 82 orthe wishbone 56 and generates the reaction force to counteract the downward load.

[0041] The torsion bar 76 is generally spaced from the housing 82 except at the attachment point between the second end portion 80 and the second end 86 of the housing 82, thereby minimizing frictional engagement during rotation of the torsion bar 76. The attachment of the second end portion 80 of the torsion bar 76 to the second end 86 of the housing 82 allows the reaction force created by the preloader 70 to be transmitted to the housing 82 and the control arm 56 to counteract the downward load. Therefore, when the preloader 70 is operated in the first mode, the torsion bar 76 is twisted or rotated and therefore exerts the first reaction force on the housing 82, which acts on the control arm 56 to counteract the downward load.When the preloader 70 is operated in the second mode, the torsion bar 76 is twisted or rotated in the same direction or in the opposite direction to that in which the torsion bar 76 was rotated in the first mode, and therefore exerts the second reaction force on the housing 82, which acts on the control arm 56 to counteract the downward load.

[0042] A portion of the torsion bar 76 may be selectively rotatable about the longitudinal axis 74. Specifically, one end of the torsion bar 76 is fixed to the housing 82 to prevent rotation of that end, while the other end of the torsion bar 76 is rotatable to twist or partially reverse the torsion bar 76. For example, the first end portion 78 of the torsion bar 76 is selectively rotatable about the longitudinal axis 74 to apply the torsional force to the torsion bar 76 to provide the first and second reaction forces that counteract the downward load. Therefore, when the spoiler 18 is extended to the desired position, the downward load is exerted on the structure 14, which acts on the control arm 56 and therefore on the housing 82 of the pretensioner 70, and the rotation of the torsion bar 76 causes the torsion bar 76 to exert the torsional force on the housing 82 and thereby on the control arm 56 to counteract the downward load.For example, when the first end portion 78 of the torsion bar 76 is rotated counterclockwise, as indicated by arrow 98 (see . Fig. 3 and Fig. 4), the torsional force increases. It will be appreciated that the torsion bar 76 may be attached to the housing 82 in configurations other than that shown, such that clockwise rotation of the torsion bar 76 may increase the torsional force instead of counterclockwise rotation.

[0043] A distal portion 100 of the second end portion 80 of the torsion bar 76 and the second end 86 of the housing 82 may be splined together to prevent rotation of the torsion bar 76 at this attachment point. Generally, the splines of the second end 86 of the housing 82 are disposed within the housing 82 to cooperate with the splines of the distal portion 100 of the second end portion 80 of the torsion bar 76. It will be appreciated that the second end portion 80 of the torsion bar 76 may be attached to the housing 82 in other suitable configurations, such as keyed, flat, tapered, etc., or may be secured to the housing 82 by any suitable method, such as welding, adhesive, etc.

[0044] With reference to Fig. 4 and Fig. 5, the pretensioner 70 may include an actuator 102 coupled to the first end portion 78 of the torsion bar 76 to selectively rotate the first end portion 78 of the torsion bar 76. The actuator 102 is further attached to the structure 14. Therefore, the actuator 102 supports the first end portion 78 of the torsion bar 76. The actuator 102 may, for example, be attached to the structure 14. In certain embodiments, the actuator 102 is attached to the frame adjacent to a bumper beam 104. In other embodiments, the actuator 102 is attached to the bumper beam 104. The bumper beam 104 may extend across the vehicle 10 (see Fig. 6), for example, between the first and second wheel assemblies 32, 34. It will be appreciated that the actuator 102 may be mounted at any suitable position on the structure 14. The actuator 102 is in Fig. 3 removed for illustration purposes only.

[0045] With further reference to Fig. 4 and Fig. 5, in certain embodiments, the actuator 102 may include a motor 106 (referred to herein as a second motor 106) coupled to the first end portion 78 of the torsion bar 76 for selectively rotating the first end portion 78 of the torsion bar 76. Furthermore, the actuator 102 may include a drive mechanism 108 coupled to the second motor 106 and the first end portion 78 of the torsion bar 76 for selectively rotating the first end portion 78 of the torsion bar 76. For example, actuation of the second motor 106 moves, rotates, or drives the drive mechanism 108, which rotates the first end portion 78 of the torsion bar 76. The drive mechanism 108 may be a planetary gear set, a multi-stage planetary gear set, a belt drive, or any other suitable mechanism to rotate the torsion bar 76 and hold it in the desired position.If the drive mechanism 108 is a planetary gear set, in certain embodiments, the planetary gear set may optionally be concentric or coaxial with the longitudinal axis 74. The second motor 106 may be an electromechanical motor, an electric motor, or any other suitable mechanism for operating the drive mechanism 108. It will be appreciated that a position sensor 110 may be coupled to the torsion bar 76, the drive mechanism 108, and / or a portion of the second motor 106 to detect the position of the torsion bar 76 and / or the drive mechanism 108.

[0046] The second end portion 80 of the torsion bar 76 is fixed to the housing 82 to prevent rotation of that end, while the first end portion 78 of the torsion bar 76 is rotatable when the second motor 106 is actuated to twist or partially reverse the torsion bar 76. A distal portion 112 of the first end portion 78 of the torsion bar 76 may be provided with gearing, and a portion of the drive mechanism 108 may be provided with gearing to cooperate with the distal portion 112 of the first end portion 78. Therefore, movement of the drive mechanism 108 correspondingly rotates the first end portion 78 of the torsion bar 76. It should be appreciated that the first end portion 78 of the torsion bar 76 and the drive mechanism 108 may be coupled together in any suitable configuration, for example, keyed, flat, conical, etc., or coupled together by any suitable method, such as welding, an adhesive, etc. It will also be appreciated that the first end portion 78 of the torsion bar 76 and the drive mechanism 108 may be coupled together by any suitable configurations / components to rotate the torsion bar 76.

[0047] Actuation of the actuator 102 can rotate the first end portion 78 of the torsion bar 76 to the desired position to exert the desired reaction force that counteracts the downward load applied to the structure 14. A controller 114 can be used to selectively actuate the pretensioner 70, and more specifically, the actuator 102, to rotate the torsion bar 76 to the desired position. The controller 114 can generally be part of an electronic control module that communicates with various components of the vehicle 10. For example, the controller 114 can communicate with the first and second motors 28, 106 and also with the position sensors 30, 110, if used. As another example, the controller 114 can communicate with a speed sensor 116 to determine the speed at which the vehicle 10 is moving.The speed of the vehicle 10 can be used by the controller 114 to determine aerodynamic information and thereby determine the downward load exerted on the structure 14. Specifically, the controller 114 can compile data from the position sensors 30, 110 and the speed sensor 116, and also calculate data for moving the spoiler 18 to the desired position and driving the drive mechanism 108 to rotate the torsion bar 76 to the desired position. Simply put, the controller 114 can transmit a signal to the actuator 102 to operate it in the first or second mode. It will be appreciated that more than one controller 114 may be used and that these controllers may communicate with one another.

[0048] The controller 114 includes a processor 118 and a memory 120 in which instructions for communicating with the spoiler 18, the actuator 102, the speed sensor 116, and / or the position sensors 30, 110 are recorded. The controller 114 is configured to execute the instructions from the memory 120 using the processor 118. For example, the controller 114 may be a host machine or a distributed system, e.g., a computer, such as a digital computer or microcomputer, acting as a vehicle control module and / or as a proportional-integral-derivative (PID) controller having a processor and a memory 120 having accessible, non-transitory, and computer-readable storage, such as read-only memory (ROM) or flash memory.The controller 114 may also include random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), a high-speed clock, analog-to-digital (A / D) and / or digital-to-analog (D / A) conversion circuitry, any necessary input / output circuitry and associated devices, as well as any necessary signal conditioning and / or signal buffering circuitry. Therefore, the controller 114 may include all software, hardware, memory 120, algorithms, interconnections, sensors, etc., necessary to monitor and control the first and second motors 28, 106, the speed sensor 116, and the position sensors 30, 110. Thus, a control method may be embodied as software or firmware associated with the controller 114.It will be appreciated that the controller 114 may also include any device capable of analyzing data from the position sensors 30, 110 and the speed sensor 116, comparing data, and making the necessary decisions required to control and monitor the first and second motors 28, 106, the speed sensor 116, and the position sensors 30, 110.

[0049] Therefore, the controller 114 may communicate with the actuator 102 to actively control the pretensioner 70. For example, the actuator 102 may be activated when the pretensioner 70 is in the first mode and / or the second mode. The controller 114 may determine the amount of torque (rotation or twist) to be applied to the torsion bar 76 based on the angle of the spoiler 18 and / or the speed of the vehicle 10 and / or the amount of downward load applied to the structure 14 and / or the height of the structure 14 relative to the road 16 using a height sensor, the amount of weight being placed in or removed from the vehicle 10, etc. The controller 114 may store one or more calculations or algorithms that may be used to determine the position of the pretensioner 70.Optionally, a transducer may be connected to the controller 114 and the actuator 102 to assist in controlling the position of the pretensioner 70 and specifically the torsion bar 76.

[0050] Additionally, the actuator 102 may also optionally include one or more stops to limit one or more directions of rotation of the torsion bar 76. Therefore, when the stops are used, one stop may limit the rotation of the torsion bar 76 to a minimum torque applied to the torsion bar 76, and another stop may limit the torque of the torsion bar 76 to a maximum torque applied to the torsion bar 76.

[0051] To Fig. 4, the suspension system 12 may further include a piston shock absorber 122 coupled to the steering knuckle 44 and partially disposed within the space 68 between the first and second arm segments 60, 62. In certain embodiments, the piston shock absorber 122 is coupled to the structure 14 and the first side 52 of the steering knuckle 44. The piston shock absorber 122 extends through the space 68, and therefore, a portion of the piston shock absorber 122 is disposed above the control arm 56, and a portion of the piston shock absorber 122 is disposed below the control arm 56. In other words, a portion of the piston shock absorber 122 is disposed above the longitudinal axis 74 with respect to the axis 46, and a portion of the piston shock absorber 122 is disposed below the longitudinal axis 74 with respect to the axis 46. Therefore, the control arm 56 and the housing 82 of the preload device 70 cooperate to surround a portion of the piston shock absorber 122.

[0052] The piston shock absorber 122 may include a cylinder with a piston movably disposed within the cylinder. The piston shock absorber 122 dampens the movement of the structure 14 or the sprung mass of the vehicle 10 as the vehicle 10 travels over the road 16. For example, the piston shock absorber 122 may dampen the movement of the structure 14 as the vehicle 10 travels over bumps, holes, etc. The preloader 70 may also dampen the movement of the structure 14, in addition to the preloader 70 being able to substantially maintain the vertical position of the structure 14 in the first mode or change the vertical position of the structure 14 in the second mode.

[0053] The piston shock absorber 122 is operable without the use of a coil spring surrounding the cylinder. Simply stated, the piston shock absorber 122 does not use a coil spring, as discussed above in the Background section.

[0054] In certain embodiments, the control arm 56 is further defined as a first control arm 56 (and is referred to as the first control arm 56 in the discussion below), and the suspension system 12 may further include a second control arm 126 (see Fig. 3 and Fig. 4), which is spaced apart from the first control arm 56. The second control arm 126 is also coupled to the steering knuckle 44. Specifically, the second control arm 126 is coupled to the lower segment 50 of the steering knuckle 44. Additionally, the second control arm 126 is coupled to the structure 14. Therefore, the second control arm 126 generally couples the steering knuckle 44 to the structure 14. For example, a ball joint may couple the steering knuckle 44 to the second control arm 126.

[0055] How best in Fig. 4, in certain embodiments, the first control arm 56 is coupled to the steering knuckle 44 above the second control arm 126. In other words, the second control arm 126 is disposed below the first control arm 56, and therefore, the second control arm 126 is disposed closer to the road 16 than the first control arm 56. Simply stated, the second control arm 126 is disposed below the longitudinal axis 74 relative to the axle 46. The first control arm 56 may be referred to as an upper control arm, and the second control arm 126 may be referred to as a lower control arm.

[0056] With reference to Fig. 3, the second control arm 126 is rotatable about a first axis 128 spaced from the longitudinal axis 74. In certain embodiments, the first axis 128 and the longitudinal axis 74 may be spaced apart and substantially parallel to each other. As the first and / or second control arms 56, 126 rotate about the longitudinal axis 74 or the first axis 128, respectively, the structure 14 moves accordingly relative to the road 16. For example, the structure 14 may be moved upwardly or downwardly relative to the steering knuckle 44, the road 16, or the axle 46.

[0057] As in Fig.6, the suspension system 12 may include suspension components on both sides of the vehicle 10. Thus, the components discussed above may be duplicated for the other side of the vehicle 10. In other words, the suspension components may be coupled to the second wheel assembly 34. Therefore, one preloader 70 may be used for the first wheel assembly 32, and a second preloader 130 may be used for the second wheel assembly 34.Thus, a second steering knuckle 132 may be coupled to the second wheel assembly 34; a third control arm 134, which may also be referred to as an upper control arm, may be coupled to the second steering knuckle 132; a fourth control arm 136, which may also be referred to as a lower control arm, may be coupled to the second steering knuckle 132; a second piston shock absorber 138 and a second actuator 140 may be coupled to the second steering knuckle 132, etc. Each of these additional suspension components may have the same features as discussed above, except that these components operate along the opposite side of the vehicle 10.

[0058] Furthermore, the controller 114, discussed above, may communicate with both pretensioners 70, 130 and thus with both actuators 102, 140 to provide the desired amount of torsional force to the respective torsion bars 76. For example, the controller 114 may communicate with each of the actuators 102, 140 to provide a substantially proportional or substantially equal torsional force to each of the torsion bars 76 to provide the substantially proportional or substantially equal reaction force on both sides of the vehicle 10 to counteract the downward load. Alternatively, the controller 114 may communicate with each of the actuators 102, 140 to provide different torsional forces to each of the torsion bars 76 to create different reaction forces on the sides of the vehicle 10 to counteract the downward load.

[0059] The suspension system 12 described herein is configured to provide a compact package for the suspension system 12 within the vehicle 10. Additionally, the pretensioners 70, 130 can provide active control to substantially maintain the vertical position of the structure 14 and / or to change the vertical position of the structure 14. Furthermore, the pretensioners 70, 130 can actively control the pitch angle and / or the roll angle of the structure 14.

[0060] Pitching motion may occur when the vehicle 10 accelerates or decelerates, causing the structure 14 to rock forward or backward. Therefore, the controller 114 may actuate the actuators 102, 140 to minimize the pitch angle of the structure 14. Generally, the controller 114 may use some of the data / information, etc., discussed above, as well as acceleration / deceleration data of the vehicle 10, to determine the desired positions of the biasing devices 70, 130 to minimize the pitch angle.

[0061] Roll may occur when the vehicle 10 is cornering (moving around a bend / curve), causing the structure 14 to rock away from the center of the bend. Therefore, the controller 114 may actuate the actuators 102, 140 to minimize the roll angle of the structure 14. In general, the controller 114 may use some of the data / information, etc., discussed above to determine the desired positions of the biasing devices 70, 130 to minimize the roll angle.

[0062] Furthermore, when a predetermined axial force is applied to the front 142 or rear 40 of the vehicle 10, positioning the preloaders 70, 130 adjacent the bumper beam 104 allows the torsion bars 76 to disengage and translate into the bumper beam 104 in certain situations to minimize reinforcement of the structural bars of the vehicle 10, thereby allowing the structural bars to translate to absorb energy, and / or allowing the torsion bars 76 to deform to absorb energy in certain situations. Additionally, the preloaders 70, 130 can be actuated by the controller 114 to act as a stabilizer for the vehicle 10.

Claims

[1] Suspension system (12) for a vehicle (10), the suspension system (12) comprising: a steering knuckle (44); a control arm (56) coupled to the steering knuckle (44), the control arm (56) having a proximal end (58) with a first arm segment (60) and a second arm segment (62) each extending outwardly away from the proximal end (58) to a respective first and second distal end (64, 66) to define a space (68) between the first and second arm segments (60, 62); characterized by : a preload device (70) disposed at least partially within the space (68) between the first and second arm segments (60, 62), the preload device (70) being coupled to at least one of the first and second distal ends (64, 66) of the first and second arm segments (60, 62), respectively, such that actuation of the preload device (70) provides a first reaction force counteracting a downward load acting on the control arm (56), the first reaction force being substantially proportional to the downward load to substantially maintain a position of the steering knuckle (44). [2] The suspension system (12) for a vehicle (10) of claim 1, wherein the preloading means (70) is disposed between the first and second distal ends (64, 66) of the first and second arm segments (60, 62), respectively, the first and second distal ends (64, 66) being spaced apart from one another along a longitudinal axis (74), and wherein the preloading means (70) is operated in a first mode to provide the first reaction force substantially proportional to the downward load and in a second mode to provide a second reaction force opposing the downward load acting on the control arm (56) such that the second reaction force is different from the downward load, thereby enabling the control arm (56) to be selectively rotated about the longitudinal axis (74) to vary the position of the control arm (56) relative to the steering knuckle (44). [3] The suspension system (12) for a vehicle (10) of claim 1, wherein the preloading means (70) comprises a torsion bar (76) disposed within the space (68) and extending along a longitudinal axis. [4] The suspension system (12) for a vehicle (10) of claim 3, wherein the preloading device (70) includes a housing (82) attached to one of the first and second distal ends (64, 66) of the first and second arm segments (60, 62), respectively, for coupling the preloading device (70) to the control arm (56), the control arm (56) and the housing (82) being selectively rotatable as a unit about a longitudinal axis (74), and the torsion bar (76) being at least partially disposed within the housing (82). [5] The suspension system (12) for a vehicle (10) of claim 3, wherein the preloading device (70) includes a housing (82) attached to both the first and second distal ends (64, 66) of the first and second arm segments (60, 62), respectively, for coupling the preloading device (70) to the control arm (56), the control arm (56) and the housing (82) being selectively rotatable as a unit about the longitudinal axis (74), and the torsion bar (76) being at least partially disposed within the housing (82). [6] The suspension system (12) for a vehicle (10) of claim 5, wherein the housing (82) has a first length and the torsion bar (76) has a second length greater than the first length such that the torsion bar (76) extends outside the housing (82). [7] The suspension system (12) for a vehicle (10) of claim 6, wherein the torsion bar (76) has a first end portion (78) and a second end portion (80) spaced apart along the longitudinal axis (74), the first end portion (78) being fixed to the housing (82) and the first end portion (78) being disposed outside the housing (82), and the first end portion (78) of the torsion bar (76) being selectively rotatable about the longitudinal axis (74) to apply a torsional force to the torsion bar (76) to provide the first reaction force that counteracts the downward load. [8] The suspension system (12) for a vehicle (10) of claim 7, wherein the pretensioner (70) includes an actuator (102) coupled to the first end portion (78) of the torsion bar (76) for selectively rotating the first end portion (78) of the torsion bar (76). [9] The suspension system (12) for a vehicle (10) of claim 8, wherein the actuator (102) includes a motor (106) coupled to the first end portion (78) of the torsion bar (76) for selectively rotating the first end portion (78) of the torsion bar (76). [10] The suspension system (12) for a vehicle (10) of claim 9, wherein the actuator (102) includes a drive mechanism coupled to the motor (106) and the first end portion (78) of the torsion bar (76) for selectively rotating the first end portion (78) of the torsion bar (76).

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