Frame with variable geometry for vehicles

Abstract

A frame (1) with variable geometry for vehicles comprises a first frame part (2), a second frame part (3) and a third frame part (4), wherein the first frame part (2) is movable with respect to the second frame part (3) in a direction of a longitudinal axis (A) of the frame (1), wherein the second frame part (3), together with the first frame part (2), is movable with respect to the third frame part (4) in a direction that is perpendicular to said longitudinal axis (A).

Description

Frame with variable geometry for vehiclesBACKGROUND OF THE INVENTION

[0001] The present invention relates to a front frame with variable geometry for vehicles, in particular, but not exclusively, for motor vehicles designed to be used in sporting competitions.PRIOR ART

[0002] IT 0001426745 discloses a front frame for motor vehicles, conceived, in particular, for motor vehicles designed to be used in sporting competitions, in which extreme conditions of use of the motor vehicle can be reached, in particular on bends, where bending angles up to even 65° can be reached.

[0003] The frame is made of two separate parts that are linked so as to be able to vary the reciprocal position thereof, in a direction that is transverse to the direction of travel of the motor vehicle, making it thus possible to vary the lateral stiffness of the frame.DESCRIPTION OF THE INVENTION

[0004] Different types of frame exist, which differ from one another according to the type of motor vehicle in which they are installed and for which they have been designed, dynamic features and dynamic performance, the torsional and transverse stiffness features that differ according to intended use, steering geometry, different wheelbases and centres of gravity, higher or lower production costs that depend on the differing constructional complexity.

[0005] Constructional complexities can affect production costs and productivity significantly because they may cause high production rejection percentages, in particular when very exacting production tolerances are required.

[0006] In any case, any frame for motor vehicles, in all cases, has to meet a technical requirement that consists of ensuring neutral driving in right-hand and left-hand curves, which depends directly on the correct longitudinal alignment between a plane that contains the steering axis and a plane that is orthogonal to the axis of the fulcrum of the rear swingarm at the centre line of the motor vehicle.

[0007] This correct alignment must ensure optimum driving neutrality, with a resulting improvement of dynamic performance and general safety of the motor vehicle.

[0008] One object of the present invention is to provide a frame with variable geometry fora motor vehicle that enables a correct longitudinal alignment to be maintained between a plane containing the steering axis and a plane orthogonal to the axis of the fulcrum of the rear swingarm in all conditions of use, also with a very small alignment tolerance, minimizing production rejections, with a consequent reduction in production costs and an increase in productivity.

[0009] The object of the invention is achieved by a frame with variable geometry for a motor vehicle according to claim 1.

[0010] Owing to the invention, it is possible to optimize the performance and safety of a motor vehicle, in all conditions of use, and increase productivity, reducing rejections and production costs.SHORT DESCRIPTION OF THE DRAWINGS

[0011] Further features and advantages of the invention will be clear from the following description, which is provided merely by way of non-limiting example, with reference to the attached drawings, in which: figure l is a perspective view of a frame for motor vehicles according to the invention; figure 2 is a rear view of the frame for motor vehicles for motor vehicles of figure 1; figure 3 is a top view of the frame for motor vehicles of figures 1 and 2.DETAILED DESCRIPTION OF THE INVENTION

[0012] The figures illustrate an embodiment of a frame 1 with variable geometry for a motor vehicle, according to the invention.

[0013] The frame 1 comprises a first frame part 2 in which the steering tube 15 of the motor vehicle is obtained; a second frame part 3, which constitutes the front frame of the motor vehicle and a third frame part 4 that constitutes the central frame of the motor vehicle, to which the engine of the motor vehicle is fixed.

[0014] The first frame part 2 and the second frame part 3 are movable with respect to the third frame part 4. Further, the first frame part 2 is movable with respect to the second frame part 3.

[0015] The first frame part 2 is housed in a seat 16 obtained in the second frame part 3 and can slide in said seat, with respect to the second frame part 3, in the direction of a longitudinal axis A of the vehicle.

[0016] Sliding of the first frame part 2 with respect to the second frame part 3 is controlledby a first linear actuator 6 connected both to the first frame part 2 and to the second frame part 3.

[0017] Owing to the sliding of the first frame part 2 with respect to the second frame part 3, it is possible to vary the steering angle of the motor vehicle, the pitch, and the height of the centre of gravity of the motor vehicle.

[0018] The second frame part 3 is fitted slidably to a first crosspiece 5, placed in a front zone of the third frame part 4 and a second crosspiece 8, placed in an intermediate zone of the third frame part 4.

[0019] The second frame part 3, together with the first frame part 2, slides with respect to the third frame part 4 in a direction that is perpendicular to the longitudinal axis A of the frame 1 (figure 3).

[0020] Sliding of the second frame part 3 with respect to the third frame part 4 is controlled by a pair of second linear actuators 7, connected to the second frame part 3 and to the third frame part 4.

[0021] The movement of the second frame part 3 on the first crosspiece 5 is counteracted by a first pair of springs 12, interposed between the first frame part 3 and the second frame part 4, on sides opposite the first frame part 3.

[0022] Similarly, the movement of the first frame part 3 on the second crosspiece 8 is counteracted by a second pair of springs 13, interposed between the first frame part 3 and the second frame part 4, on sides opposite the first frame part 3.

[0023] The first pair of springs 12 and the second pair of springs 13 prevent the second frame part 3 coming into contact with the third frame part 4 during the lateral sliding movements acting as spacing elements when they are compressed in “a pack”.

[0024] An initial position of the second frame part 3 with respect to the third frame part 4, for example a position set during the step of building the motor vehicle, is adjustable by a first micrometric adjusting device 10, associated with the first crosspiece 5, and a second micrometric adjusting device 11, associated with the second crosspiece 8.

[0025] The first micrometric adjusting device 10 and the second micrometric adjusting device 11 are configured to perform a micrometric adjustment of the reciprocal position of the second frame part 3 and of the third frame part 4. Micrometric adjusting enables a possible misalignment of the longitudinal axis of the frame as a whole that arises from the normal production tolerances to be corrected precisely. In fact, the aforesaid micrometric adjusting devices enable the axis of the steering tube 15 to be aligned correctly with respectto the centre line of the rear swingarm 17 of the frame 1 if there is a misalignment of the longitudinal axis of the frame.

[0026] The alignment of the axis of the steering tube 15 is controlled by a pair of sensors 14, fitted to the third frame part 4, on opposite sides with respect to the second frame part 3, each of which detects the position of a respective reference element 9 fixed to a respective side of the second frame part 3.

[0027] The possibility of correcting a possible misalignment of the longitudinal axis A of the frame 1 enables wider tolerances to be used during the step of producing the frame 1, also possible production errors to be compensated and production waste to be substantially reduced to zero.

[0028] The first frame part 2, the second frame part 3 and the third frame part 4 can be made of the same material or of different materials, both to obtain advantages of a financial character and to improve the performance of the frame 1 according to the invention.

[0029] The first linear actuator 6 and the second linear actuators 7 can be of mechanical, electromechanical, hydraulic, electro-hydraulic, magnetic, electromagnetic, electronic type, or of any other type.

[0030] The first linear actuator 6 and the second linear actuators 7 can be actuated by the driver of the vehicle, or be actuated remotely, by a command-and-control device located on the motor vehicle.

[0031] In the command-and-control device, reciprocal positions of the parts of the frame 1 can be stored, which depend for example on the features of the route that the motor vehicle has to travel, and on possible satellite signals that identify the position of the motor vehicle on the route, so as to vary in real time the geometry of the frame to adapt the frame instant by instant to the features of the route.

[0032] The frame 1 according to the invention, owing to the three-part structure the reciprocal positions of which can be varied, enables the dynamic behaviour of the motor vehicle to be adjusted in any condition of use, by being able to increase the wheelbase of the vehicle, together with lowering the centre of gravity, on fast portions of the route, thus ensuring greater traction and greater stability, and thus being able to reduce the steering angle and the wheelbase of the motor vehicle, with consequent raising of the centre of gravity of the motor vehicle on bends and counter bends with a small / medium radius, increasing the handleability of the motor vehicle even in changes of direction, in the speed of entering, travelling through and exiting every single bend.

[0033] Further, the transverse movement of the second frame part 3 with respect to the third frame part 4 enables a controlled misalignment to be achieved that further increases the efficacy of the frame 1 in all conditions of use.

[0034] The driver of the motor vehicle can configure the longitudinal and transverse position of the frame 1 within parameters preset by the manufacturer with resulting advantages in terms of performance, feeling and safety.

Claims

CLAIMS1. Frame (1) with variable geometry for vehicles characterized in that it comprises a first frame part (2), a second frame part (3) and a third frame part (4), wherein the first frame part (2) is movable with respect to the second frame part (3) in a direction of a longitudinal axis (A) of the frame (1), wherein the second frame part (3), together with the first frame part (2), is movable with respect to the third frame part (4) in a direction that is perpendicular to said longitudinal axis (A).

2. Frame (1) according to claim 1, wherein the first frame part (2), comprising a steering tube (15) of the motor vehicle, is housed in a seat (16) of the second frame part (3) and is slidable inside said seat (16).

3. Frame (1) according to claim 1, or 2, wherein the second frame part (3) is slidable on a first crosspiece (5) and on a second crosspiece (8) of the third frame part (4).

4. Frame (1) according to one of claims 1 to 3, wherein a movement of the first frame part (2) with respect to the second frame part (3) is driven by a first linear actuator (6).

5. Frame (1) according to claim 3, or 4, wherein a movement of the second frame part (3) with respect to the third frame part (4) is driven by a pair of second linear actuators (7).

6. Frame (1) according to one of claims 3 to 5, wherein a first pair of springs (12) is interposed between the first frame part (3) and the second frame part (4) on the first crosspiece (5), wherein the springs (12) are arranged on opposite sides with respect to the first frame part (3).

7. Frame (1) according to one of claims 3 to 6, wherein a second pair of springs (13) is interposed between the first frame part (3) and the second frame part (4) on the second crosspiece (8), wherein the springs (13) are arranged on opposite sides with respect to the first frame part (3).

8. Frame (1) according to one of claims 3 to 7, further comprising a first micrometric adjusting device (10), associated with the first crosspiece (5), and a second micrometric adjusting device (11), associated with the second crosspiece (8), whereinthe first micrometric adjusting device (10) and the second micrometric adjusting device (11) are configured to perform a micrometric adjustment of the reciprocal position of the second frame part (3) and of the third frame part (4).

9. Frame (1) according to one of the preceding claims, further comprising a pair of sensors (14), fitted to the third frame part (4), on opposite sides with respect to the second frame part (3), wherein each sensor (14) is configured to detect a position of a respective reference element (9) fixed to a respective side of the second frame part (3).

10. Frame (1) according to one of claims 4 to 9, wherein the first linear actuator (6) and the second linear actuators (7) are operationally associated with a command and control device installed on the vehicle, wherein an operation of the first linear actuator and / or of the second linear actuator can be controlled by a driver of the vehicle via the command and control device, or remotely, on the basis of reciprocal positions of said first part (2), second part (3), and third part (4) that are stored in the command and control device, said reciprocal positions depending on features of a route on which the vehicle moves and / or on satellite signals that identify the position of the vehicle on the route.

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