AU2016203726A1 - Parametric chassis system for vehicles, comprising four suspension elements, incorporating a lateral torsion bar and co-axial damper unit, in a box-module, that allows central location of heavy items, such as batteries. - Google Patents

Abstract

PARAMETRIC CHASSIS SYSTEM FOR VEHICLES, COMPRISING FOUR SUSPENSION ELEMENTS, INCORPORATING A LATERAL TORSION BAR AND CO-AXIAL DAMPER UNIT, IN A BOX-MODULE, THAT ALLOWS CENTRAL LOCATION OF HEAVY ITEMS, SUCH AS A parametric chassis system for vehicles, comprising a rear subframe, formed by a pair of two opposed box-panels (20) encasing two pre-fabricated suspension-box-modules (17) connected to a pair of trailing arms (5), for the rear suspension, each suspension-box-module (17) comprising a lateral torsion bar (1) and an enveloping co-axial damper unit (9) and locating the two trailing arms (5) via bases (4), whereby a track of the rear subframe is defined by a size of a track panel used as a spacer connecting the two opposed suspension-box-modules (17), a front subframe, which corresponds to the reversed rear subframe, whereby two leading arms (5) located by the front subframe locate wheels and accommodate steering via two swivels, and two longitudinal panels which define a wheel base (39) of the vehicle (53) and connect the rear subframe to the front subframe, wherein the four suspension-box-modules (17) of the front subframe and the rear subframe in fully active/adaptive mode, feature asymmetric steering characteristics are reproduced on each corner of the chassis, feature electronic control without mechanical connection and give the vehicle control of ride-height, control of body-roll and control of dynamic handling, by always ensuring the verticality of the wheels, to the desired degree.

Description

PARAMETRIC CHASSIS SYSTEM FOR VEHICLES, COMPRISING FOUR SUSPENSION ELEMENTS, INCORPORATING A LATERAL TORSION BAR AND CO-AXIAL DAMPER UNIT, IN A BOX-MODULE, THAT ALLOWS CENTRAL LOCATION OF HEAVY ITEMS, SUCH AS BATTERIES.

DESCRIPTION A parametric chassis system for road vehicles, comprising four suspension elements, incorporating a lateral torsion bar and an enveloping co-axial damper unit, situated inside a box-structure, that allows that storage of heavy items, such as batteries or fuel cells, within the chassis. The suspension element uses a longitudinal arm which transmits drive and brake forces-to the wheel. The suspension module, which incorporates a lateral torsion bar and a coaxial damper unit, acts as a structural member of the chassis, having active-adaptive and asymmetrical-steer features.

Up until now, such a suspension and chassis arrangement has not been devised. In recent years there has been a tendency to increase the wheelbase, due to cabin-space and handling (understeering) considerations. The increase of the wheelbase results in a heavier vehicle, which is further induced by the need to incorporate heavy items such batteries or fuel cells.

It is an object of the present invention to substantially overcome or ameliorate one or more of the above disadvantages, or at least provide a useful alternative. A first aspect of the present invention provides a parametric chassis system for vehicles, comprising a rear subframe, formed by a pair of two opposed box-panels encasing two pre-fabricated suspension-box-modules connected to a pair of trailing arms, for the rear suspension, each suspension-box-module comprising a lateral torsion bar and an enveloping coaxial damper unit and locating the two trailing arms via bases, whereby a track of the rear subframe is defined by a size of a track panel used as a spacer connecting the two opposed suspension-box-modules, a front subframe, which corresponds to the reversed rear subframe, whereby two leading arms located by the front subframe locate wheels and accommodate steering via two swivels, and two longitudinal panels which define a wheel base of the vehicle and connect the rear subframe to the front subframe, wherein the four suspension-box-modules of the front subframe and the rear subframe in fully active/adaptive mode, feature asymmetric steering characteristics are reproduced on each comer of the chassis, feature electronic control without mechanical connection and give the vehicle control of ride-height, control of body-roll and control of dynamic handling, by always ensuring the verticality of the wheels, to the desired degree. A second aspect of the present invention provides a body-shell of a vehicle, comprising the parametric chassis system according the above first aspect, and external body-shell members, wherein the body-shell formed by the chassis system and the body-shell members is supplementary self-carrying.

At least a preferred embodiment utilises a multiplicity of identical subsystems, providing high structural rigidity, for a given wheelbase: and a low-cost, compact, light construction. Furthermore, the bay accommodating the heavy items is inherently designed-in the chassis and not fitted as an afterthought. The well known suspension of leading and trailing arms is coupled to a new concept of springing, using a lateral torsion bar and an enveloping co-axial damper unit, which can be activated in an active-adaptive manner. The resulting chassis can be produced in a cost-effective way, utilising the concept of component multiplicity, positioning four identical suspension modules on each corner of the chassis. Furthermore, the chassis uses the modules as structural members, achieving high structural rigidity, for a given wheelbase, as the frame is made shorter by a length of two suspension arms (by comparison to adopting conventional McPherson linkages or transverse arms) while improving wheel compliance.

Preferred embodiments of the invention will be described hereinafter, by way of examples only, with reference to the accompanying drawings.

Referring to Fig.l, a section of the suspension module is shown. The lateral torsion bar, the enveloping co-axial damper unit, their location on the frame, the suspension arm and wheel are presented.

In Fig.2 an alternative locating system (using a bracket) for the suspension arm is shown.

In Fig.3 a locating arrangement for the reactive springing of the active-adaptive control is shown.

In Fig.4 an alternative to the variable anchoring, (locating the fixing end) of the torsion bar, is shown.

In Fig. 5 the power transmission system, with a belt through the arm, is displayed.

In Fig. 6 the suspension system without the panel, the arm and the wheel, as well as the sections of the suspension module and the track element of the chassis are displayed.

In Fig. 7 an alternative hinged upper section of the arm of the paneled suspension is shown.

In Fig. 8 a system of arm with upper solid section and secondary inner section is displayed.

In Fig. 9 the chassis is displayed by half, as it is externally. On the one side, the partial elements of the suspension and the front supplementary external upper-section of the body-shell are shown.

In Fig. 10 a schematic section of an alternative front assembly is displayed, where the suspension arms are hinged.

In Fig. 11 an alternative arm of the suspension and the wheel are displayed.

In Fig. 12 an alternative arm of the suspension, the wheel, the damper in a section, the torsion bar and the track element are displayed.

In Fig. 13 the transmission system of the arm via a belt is displayed.

In Fig. 14 the invented system is displayed in perspective, with a section of two modules.

In Fig. 15 one quarter of the frame is displayed in perspective, where the basic parts of the invention are shown. Namely, the motor, the transmission system through the arm, the system of asymmetric steering, module in section, the torsion bar and the co-axial system of damper and the track element.

In Fig. 16 a plan view of one quarter of the frame is displayed.

In Fig. 17 the system of the chassis is displayed in plan view, that is formed by the integration of four quarters.

Referring to a selected indicative example of industrial application of the invention, a number of the main sections and components of the system are listed below.

More specifically, the basic parts of the invention are the following : 1. Suspension bar. 2. Suspension axis. 3. Anchoring end (Passive end or Active end). 4. End connection base (Suspension connection). 5. Suspension arm. 6. Wheel. 7. Fastener securing the arm to the torsion bar. 8. Connection unit of suspension arm to the torsion bar. 9. Damper (Active or not). 10. Wings of damper. 11. Base of wings (of damper). 12. Connection of the torsion bar to the wings of damper. 13. Damper flanges (seals). 14. Feed and control valves of liquid for the damper. 15. Support bearing (of suspension). 16. Inner bearing (of support of the suspension). 17. Suspension box-module, comprising lateral torsion-bar and enveloping co-axial damper unit. 18. Anchoring of damper to the box-module. 19. Point of anchoring of the torsion bar. 20. Panel of suspension and sleeve of position of the casing of the suspension. 21. Support guides of the suspension module, in the panel of the frame. 22. Securing section for the box-module, on the panel. 23. Securing section of the rod on the chassis. 24. Securing bulge on the bar. 25. External supporting bracket of the arm on the chassis. 26. External fastener for connection of the arm to the chassis. 27. Active end of anchoring. 28. Shank at the connection end of the reaction mechanism . 29. External support bearings (of the arm). 30. Internal support bearings of the arm . 31. Sliding mechanism of anchoring. 32. Sliding groove in the torsion bar. 33. Ring for transmission of motion (co-axial with bar). 34. Transmission belt. 35. Transmission wheels (or pulleys). 36. Support bearings. 37. Elastic cover of transmission belt. 38. Track element or member (panel). 39. Wheelbase element or member (panel). 40. Upper solid section of the suspension arm. 41. Secondary inner section of the suspension arm. 42. Hinged upper section of the suspension arm. 43. Hinged lower section of the suspension arm. 44. Steered wheel shank (king-pin spindle or swivel, for steering). 45. Supplementary exterior upper member of body shell (front and rear). 46. Storage bay of alternative fuels or batteries. 47. Total frame (chassis) of vehicle. 48. Electric motor (for power transmission and braking). 49. Slot for access in to the storage area. 50. Aerodynamic surface on the arm. 51. Universal joint (Constant velocity joint). 52. Total sub-system (Figure 16). 53. Vehicle (Figure 17) consisting of 4 sub-systems. 54. Assembly of power transmission (drive unit). 55. Assembly of the steering input (for the steered wheel). 56. Assembly for the control of pressure of the liquid for the damper. 57. Assembly for the control of the reactive force of the torsion bar (in the active spring mode).

By this invention, a frame (47) (chassis) of a vehicle is produced (Figure 14), that is cheap to manufacture, by using prefabricated sub-systems (17) and parametric components (38),(39). The chassis is simple and robust and can accept active-adaptive technology at the inner anchoring (19) of the torsion bar (1) in the suspension module (17). (Figure 6).

According to a selected application of the invention, the invented system of frame, is of chassis type (Figure 9), employing a pair of totally lagging arms (5) for the rear suspension. A sub-frame is created by two opposed panels (20), connecting the two prefabricated transverse systems (17) of bar (1)(for springing) / damper (9) in box-modules, that connect the suspension arms (5) via the bases (4) to the bars (1) (Figure 1).

The vehicle’s (rear) track is defined by the centre section of the track : element (38). (Figure 6).

The same system reversed, serves as the front suspension, with the difference that the arm (5) on its end, instead of anchoring steadily the bearing of the wheel (6), allows its rotation around an axis through the shank (44) (figure 11).

The front and rear suspensions are characterized by successive repetition (duplication), in the case of the sub-frames and for the entire frame. A frame is formed, by the use of sections of the wheelbase (39), in which the active suspensions (27, 28, 31 & 57) / dampers (9, 14, 56) and the panels of storage of batteries or alternative fuels (46) (Figure 9), all participate. This assembly, in fully active / adaptive mode has control of height, control of roll and control of dynamic handling that ensures always the verticality of the wheels to the desired degree.

In a passive mode, the invented system induces the driving characteristics (advantages and disadvantages) of lagging/advancing (trailing/leading) arms (with the necessary interventions for bump-steer, roll-steer etc). This is achieved by the contouring of the profile of the external support bearing (29) of the suspension (Figures 4, 5, 11), in combination with the design of the shank (44) (Figure 12).

That was a simplified version of the invention.

The culminating application of this innovation is the use of four identical subsystems that have active and adaptive suspension, power transmission / braking and steering for the wheel, that is based on a system of lateral torsion bar (1) (spring) and damper (9), in a box-module (17) embedded in a panel (20), connected to a motor (48), a transmission assembly (54), a transmission ring (33), transmission wheels (35), suspension arm (5), steering system (by one or two electric/hydraulic or equivalent mechanisms (55)), control assembly for the pressure of the damper liquid (56) and control assembly for reactive springing of the torsion bar (57), implementing asymmetric steering.

Asymmetric steering is defined as inducing greater steering angles on the outer (front and rear) wheels than the inner wheels.

During the vehicle’s turning process, the weight transference increases the loads on the wheels of the outer side of each axle. The outer wheels are steered by greater steering angles, whereas the inner wheels complete dynamically their rotations, steered by smaller angles, in function with the differential in loading between the outer and the inner wheel. In quasi-static dynamic conditions (with very small vehicle speeds) the front and the rear outer wheels turn and are steered, whereas the inner wheels turn and are steered less, changing the rates of their rotation, without violating the principle of creation of an angle of lateral sliding (sideslip) according to Ackermann.

In the invented system (Figure 9), a robust total sub-frame is created for the (front and rear) suspension, that allows the creation of a storage area (46) for heavy batteries or fuel cells in the centre, that is accessible externally through a slot (49). This allows the manufacture of a total body shell that is supplementary self-carrying, in combination with external sections of the body-shell (45) (front and rear). These can be designed by a tailoring technique, with the main design criterion being the absorption of impact energy, without the need of other design arrangements (Figure 9).

The suspension box-module (17) in a panel (20) (Figure 1) encloses the suspension. The torsion bar (1), that constitutes the "spring" of the suspension, is anchored to the. panel of the frame (20) in the inner fixed point of anchoring (19). The torsion bar (1) has different cross-sections and form, in relation to its length. The bulge (24) secures its position on the frame (23). On the outer end of the bar (1), the wings (10) of the damper (9) are fixed on the bar, via sections (11), (12). During the travelling of the suspension, the bar (1) is rotated differentially around the axis (2) (as a function of its length), rotating the wings (10). The casing of the damper (9) is anchored (18) on to the casing (17) of the box-module. The damping is achieved through the relative rotary motion of the wings, fixed on the outer end of the bar (1) and the smaller fixed wings connected to the casing (9), or through any other assembly. The contained liquid in the damper (9) is sealed by flanges (13) and through valves (14) of supply/control and relevant assemblies (56), the active damping is achieved. Supplementary damping may also be achieved through already known aerodynamic surfaces (50) (Figure 10). The box-module of the suspension (17) is placed and supported with surfaces (21) and it is secured on the panel of the frame (20), through the securing section for the box-module on the panel (22).

The bar (1) is connected and secured to the suspension arm (5) through sections (7) and (8) (Figure 1). The arm (5) through the bar (1) is alternatively supported via the bracket (25) to the frame and it is secured through the fastener (26) (Figures 2, 6, 7). The suspension arm in active mode reacts on the end (27), through a shank (28) (Figure 3). Alternatively, the apparent constant (torsional rigidity) of the torsion bar changes through the transfer of the anchoring point, using a sliding mechanism (31), (32) and relevant assemblies (Figure 4).

The bar (1) constitutes a structural element of the suspension and the frame, which allows the power transmission / braking (Figure 5), using a ring for the transmission of motion (33) (Figures 5,15,16). The location of the suspension arm is achieved with inner bearings (30) (figure 4).

The arm (5) alternatively is located via bearings (29) externally on to the box-module of the suspension, that give kinematic features during the passive operation to the suspension. (Figures 4, 5,11).

The arm (5) through the wheels (35) and a belt (34) transmits motion (power and braking) to the driven wheel (6) (Figures 5,13,15,16).

The chassis (47) (Figure 14) and (53) (Figure 17) is formed by a repetitive insertion of four modules (17) in panels (20), that are connected through defining sections of the track (38) and the wheelbase (39) (Figure 6). Using traditional transmission systems (namely without belt), the drive assembly passes through the section of the track (38).

Alternatively, the wheel (6) is suspended on the panel (20) through hinged arms (42) and (43) (Figure 7 & 10), or through solid sections of an arm (5) with sections (40), (41), (Figure 8). The form of the arms (5), (40), (41) (42) & (43) depends on a kinematic/dynamic analysis of the loads that are generated during the motion.

The invented system of frame, allows its connection with supplementary external-upper-sections of the body-shell (45) (front and rear) that are designed based primarily on their impact absorbtion, disregarding other design compromises. These sections (45) constitute zones of controlled distortion (figure 9).

Claims (8)

1. A parametric chassis system for vehicles, comprising a rear subframe, formed by a pair of two opposed box-panels encasing two pre-fabricated suspension-box-modules connected to a pair of trailing arms, for the rear suspension, each suspension-box-module comprising a lateral torsion bar and an enveloping co-axial damper unit and locating the two trailing arms via bases, whereby a track of the rear subframe is defined by a size of a track panel used as a spacer connecting the two opposed suspension-box-modules, a front subframe, which corresponds to the reversed rear subframe, whereby two leading arms located by the front subframe locate wheels and accommodate steering via two swivels, and two longitudinal panels which define a wheel base of the vehicle and connect the rear subframe to the front subframe, wherein the four suspension-box-modules of the front subframe and the rear subframe in fully active/adaptive mode, feature asymmetric steering characteristics are reproduced on each comer of the chassis, feature electronic control without mechanical connection and give the vehicle control of ride-height, control of body-roll and control of dynamic handling, by always ensuring the verticality of the wheels, to the desired degree.

2. The parametric chassis system according to claim 1, further comprising panels of a storage bay for storing a battery or a fuel cell of the vehicle, the storage bay being accessible externally through a slot.

3. The parametric chassis system according to claim 1 or claim 2, wherein each suspension-box-module is anchored on one of the box-panels of the rear and front subframes at an inner anchoring point, and wherein a bulge on the torsion bar of each suspension-box-module secures the position the torsion bar relative to the corresponding rear subframe or front subframe.

4. The parametric chassis system according to any one preceding claim, wherein the trailing arms and the torsion bars of the suspension-box-modules of the rear subframe are located via brackets on the rear subframe, and wherein the leading arms and the torsion bars of the suspension-box-modules of the front subframe are located via brackets on the front subframe.

5. The parametric chassis system according to any one preceding claim, wherein the trailing and leading arms of the rear subframe and the front subframe are seated on bearings externally of the respective suspension-box-module.

6. The parametric chassis system according to any one preceding claim, wherein each suspension-box-module is supported with support surfaces in one of the box-panels and is secured on the respective box-panel though a securing section.

7. A body-shell of a vehicle, comprising the parametric chassis system according to any one preceding claim, and external body-shell members, wherein the body-shell formed by the chassis system and the body-shell members is supplementary self-carrying.

8. The body-shell according to claim 7, wherein the external body-shell members are designed by a tailoring technique, using a design criterion for high impact-energy-absorption for the body-shell, without the need of other design criteria that would have originated from the design of the chassis.