Trailer for motor vehicle with servo-assisted steering

Abstract

The invention relates to a trailer (16) for a motor vehicle; said trailer comprising a chassis (22), a coupling device for a motor vehicle, said coupling device comprising a coupling head (20) fixed to the chassis and intended to be coupled to a tow hitch (14) of a motor vehicle; a steering system (26) with steering wheels (28) pivotally connected relative to the chassis (22). The steering system further comprises an actuator (40), a module (42) for obtaining an angle of inclination of the trailer (16) relative to the motor vehicle, the steering system (26) being configured to orient the steering wheels (28) according to said angle of inclination via the actuator (40). Figure to be published with the abstract: Figure 3

Description

Title of the invention: Trailer for motor vehicle with servo-assisted steering

[0001] The invention relates to the directional guidance of a trailer coupled to a motor vehicle. The invention relates to a trailer for a motor vehicle. The invention also relates to a coupling system for a motor vehicle trailer.

[0002] A trailer is an auxiliary vehicle used to increase the loading capacity of a towing vehicle, also known as a motor vehicle. When a trailer is attached to a towing vehicle, the need to reverse makes this maneuver difficult for someone unfamiliar with it. Without experience reversing, the trailer tends to become positioned across the motor vehicle, sometimes blocking it. Consequently, the possibility of reversing deters some people from using a trailer.

[0003] Furthermore, the presence of a trailer impacts the road handling of a motor vehicle. Indeed, when cornering, the mass of the trailer tends to pull the motor vehicle towards the outside of the curve. This weight can reduce grip on downhill slopes since the trailer tends to understeer relative to the trajectory imposed by the motor vehicle. This physical phenomenon impairs road holding and therefore safety.

[0004] US patent 20040251658A1 describes a trailer for a motorized wheelchair. The trailer is designed to be towed behind a four- or three-wheeled motorized wheelchair. A first coupling element is located on a tow bar at a directional distance behind the rear wheels of the motorized wheelchair, and a second coupling element is located on a trailer drawbar during towing. The two wheels are on axles for steerable towing. A handlebar operated by a user allows the trailer's direction of travel to be changed. However, such a coupling remains complex to maneuver in reverse, especially when the trailer must avoid obstacles.

[0005] The invention aims to address at least one of the problems or drawbacks encountered in the prior art. In particular, the invention aims to facilitate reversing a motor vehicle towing a trailer. The invention also aims to optimize the safety and ease of driving a motor vehicle towing a trailer.

[0006] According to a first aspect, the invention provides a trailer for a motor vehicle; said trailer comprising: a chassis, a coupling device for a motor vehicle, said coupling device comprising a coupling head fixed to the chassis and intended to be coupled to a coupling hook of a motor vehicle; a steering system with steering wheels connected in a pivotal manner relative to the chassis; notable in that the steering system further comprises an actuator, a module for obtaining an angle of inclination of the trailer relative to the motor vehicle, the steering system being configured to orient the steering wheels according to said angle of inclination via the actuator.

[0007] It will be understood that the invention proposes a trailer equipped with an angle sensor at the coupling head and an actuator controlling the trailer's steering wheels according to the measurement from the angle sensor.

[0008] The invention provides trajectory control for the trailer based on the angle it describes relative to the vehicle. Thus, the trailer remains aligned with the motor vehicle, or follows the curve that the vehicle describes.

[0009] Preferably, the obtaining module comprises a body pivoting about a vertical pivot axis, the pivoting body comprising an insertion slot intended to receive the motor vehicle towing hook; the pivoting body being configured to be driven in rotation by the towing hook in order to obtain the angle of inclination.

[0010] Preferably, the obtaining module comprises a flap pivotally connected to the coupling head along a horizontal pivot axis; the pivoting body being pivotally mounted relative to said flap.

[0011] Preferably, the flap is configured to retain a tow ball in the coupling head.

[0012] Preferably, the steering system is configured to be activated when the trailer is reversing, and to be deactivated when the trailer is moving forward.

[0013] Preferably, the trailer includes an electric drive battery for the motor vehicle, the electric battery having a capacity of at least 5 kWh; more preferably of at least 50 kWh.

[0014] Preferably, the steering system includes a transverse rack link connecting the steering wheels, the actuator comprising a pinion motor meshing with the rack.

[0015] Preferably, the steering wheels include axes of rotation, the steering system is configured to obtain an instantaneous center of rotation position of the motor vehicle; the steering system being configured to control the actuator so that the axes of rotation of the steering wheels intersect at the instantaneous center of rotation according to the angle of inclination.

[0016] Preferably, the steering system includes: a memory with geometric data of the motor vehicle and the trailer, a computer configured to calculate the position of the instantaneous center of rotation as a function of said geometric data.

[0017] Preferably, the steering system includes means of communication with the motor vehicle in order to obtain said position of the instantaneous center of rotation.

[0018] Preferably, the steering system includes a mechanism for indexing the orientation of the steering wheels relative to each other.

[0019] Preferably, the steering system is configured to activate the trailer reversing actuator, and to deactivate the trailer forwarding actuator.

[0020] Preferably, the acquisition module includes an angle sensor.

[0021] Preferably, the steering wheels are pivotally connected to the chassis along vertical directional axes.

[0022] Preferably, the angular stop includes an outgrowth.

[0023] Preferably, the steering system includes a computer.

[0024] Preferably, the calculator is integrated into the acquisition module.

[0025] According to another aspect, the invention proposes a coupling system between a trailer and a motor vehicle, the coupling system comprising a coupling hook with a mounting plate intended to be fixed to a motor vehicle structure, a coupling ball, an arched arm connecting the coupling ball to the mounting plate; a coupling head intended to be coupled to the coupling ball; a vertical pivot axis of the coupling head relative to the coupling hook; notable in that the arched arm includes an angular stop; the coupling system comprises a body pivoting about the vertical pivot axis and connected to the coupling head, the pivoting body comprising an insertion slot configured to cooperate with the angular stop so that the arched arm drives the pivoting body around the vertical pivot axis;The coupling system further includes a module for obtaining an angle of inclination between the coupling hook and the coupling head, depending on the angular position of the pivoting body relative to the coupling head.

[0026] Preferably, the angular stop comprises a rib projecting on the arched branch; the insertion slot being configured to cooperate with the rib.

[0027] Preferably, the coupling system includes an actuator configured to control the orientation of the trailer's steering wheels according to the angle of inclination.

[0028] Preferably, the hitch hook includes a rib projecting on the arched branch.

[0029] Preferably, the rib is a vertical rib.

[0030] Preferably, the rib extends from the tow ball.

[0031] According to another aspect, the invention provides a steering system for a trailer intended to be coupled to a motor vehicle; the steering system comprising steering wheels; notable in that the steering system also comprises: a coupling hook with a mounting plate intended to be fixed to a motor vehicle structure, a coupling ball, an arched arm connecting the coupling ball to the mounting plate; a coupling head intended to be coupled to the coupling ball; the steering system further comprises an actuator, a module for obtaining an angle of inclination between the coupling hook and the coupling head, the steering system being configured to orient the steering wheels according to said angle of inclination via the actuator.

[0032] Each feature introduced by the expression "preferably" given in relation to one of the aspects of the invention applies to all other aspects of the invention.

[0033] The invention will be well understood and other aspects and advantages will become clear upon reading the following description, given with reference to the attached figures listed below.

[0034] Fig. 1 is a side view of a motor vehicle coupled to a trailer according to the invention.

[0035] Fig. 2 is a top view of a motor vehicle coupled to a trailer according to the invention.

[0036] Fig. 3 is a view from below of a motor vehicle trailer according to the invention.

[0037] Fig. 4 is a horizontal section of a trailer hitch system according to the invention.

[0038] In the following description, the term "include" is synonymous with "include" and is not limiting in that it permits the presence of other elements in the trailer or steering coupling system to which it relates.

[0039] In this description, the terms "longitudinal," "longitudinally," "transverse," and "transversely" are used with respect to the vehicle's frame of reference in the mounting configuration. "Longitudinal" refers to the vehicle's principal direction of travel. "Transverse" refers to a direction perpendicular to the vehicle's principal direction of travel. "Front" refers to the vehicle's principal direction of travel. "Rear" refers to the opposite of the front of the vehicle.

[0040] The X-axis represents the longitudinal direction, the Y-axis represents the transverse direction, and the Z-axis represents the vertical direction of the motor vehicle. These three axes define a right-handed trihedron whose orientation is preserved across the figures.

[0041] In the present description, equality between values ​​is not to be understood in the strict sense insofar as each equality allows a variation of at most 10%, preferably at most 5%, more preferably at most 2%, between these values.

[0042] In this description, the terms "vertical" and "horizontal" are not to be understood in their strict sense. Indeed, they allow an inclination of at most 20°, preferably at most 10°, more preferably at most 5°, and even more preferably at most 2°; with respect to the strict meaning of these terms.

[0043] In this description, the technical characteristics are defined in the mounting configuration of the trailer or coupling system, unless otherwise explicitly stated.

[0044] Throughout the description, the different figures use the same reference signs to designate identical or similar entities.

[0045] Figure 1 represents a motor vehicle 10, according to an embodiment of the invention. The motor vehicle 10 comprises energy storage means and at least one motor (not shown) adapted to drive said motor vehicle 10.

[0046] The motor vehicle 10 comprises a general structure. The general structure forms an outer body, or the main frame of the motor vehicle. The general structure receives a coupling system 12, also referred to as a towing system.

[0047] On the vehicle side, the coupling system 12 comprises a coupling hook 14 surmounted by a coupling ball. The coupling system 12 is capable of towing a trailer 16 forming an auxiliary vehicle, or towed vehicle; the motor vehicle 10 being the towing vehicle. The trailer 16 has a mass of at least 350 kg; preferably at least 500 kg; more preferably at least 750 kg.

[0048] On the trailer side, the coupling system 12 comprises a coupling device 18 with a coupling head 20. The axle may include a suspension system. The coupling head 20 is designed to be coupled to the tow hook 14, by being fitted onto the tow ball. The trailer 16 further comprises a frame 22 connecting the coupling head 20 to the axle. The frame 22 forms the load-bearing structure of the trailer 16. The frame 22 is capable of carrying a load in the trailer 16. The coupling head 20 forms an inverted cup, open at the bottom.

[0049] According to one embodiment, the trailer 16 includes an electric battery 24. The electric battery 24 is connected to the motor vehicle 10. It is designated as an external electric battery. The electric battery 24 has a capacity of at least 5 kWh; preferably at least 20 kWh; more preferably of at least 50 kWh; even more preferably of at least 75 kWh. The electric battery 24 increases the range of the motor vehicle 10 when the latter is electrically driven.

[0050] The trailer 16 also includes a steering system 26 with steering wheels 28. The steering wheels 28 are pivotally connected to the chassis 22 along vertical pivot axes. The steering wheels 28 are capable of rotating about their horizontal axis of rotation and pivoting about their vertical directional axis 30, which also form directional pivot axes. The steering wheels 28 form the axle. In one embodiment, the trailer comprises a single axle.

[0051] According to an alternative of the invention, the trailer comprises several axles, including a rear axle; for example with steering wheels or with fixed orientation wheels.

[0052] According to one option, the coupling device includes a flap 32 pivotally connected to the coupling head 22 along a horizontal pivot axis. The flap 32 is a safety flap configured to retain a tow ball in the coupling head. The flap 32 is integral with the trailer 16. The flap 32 is movable between an open position for inserting the tow ball and a closed or safety position for retaining the tow ball.

[0053] The motor vehicle can, for example, be a private motor vehicle or a commercial motor vehicle.

[0054] The trailer can, for example, be a loading trailer or a caravan.

[0055] Figure 2 shows a tandem vehicle comprising a motor vehicle 10 pushing a trailer 16 around a curve in reverse, according to an embodiment of the invention. They respectively constitute a tractor vehicle and a towed vehicle. The motor vehicle 10 and the trailer 16 may correspond to those shown in relation to Figure 1. Due to the curve, the trailer 16 pivots at an angle of inclination 34 relative to the motor vehicle 10. The angle of inclination is measured between the longitudinal axes 36 of the trailer 16 and the motor vehicle 10.

[0056] When cornering, the motor vehicle 10 rotates about an instantaneous center of rotation 38. The position of the instantaneous center of rotation 38 is determined by an on-board computer of the motor vehicle 10 based on the orientations of its wheels. The instantaneous center of rotation 38 can be defined in an environmental frame of reference or a frame of reference of the motor vehicle 10.

[0057] The steering system 26 further comprises an actuator 40 and a module 42 for obtaining the angle of inclination 34 of the trailer 16 relative to the motor vehicle 10. The steering system 26 is adapted to steer the steering wheels 28 depending on said angle of inclination via the actuator 40. The obtaining module 42 is a control module driving the actuator 40.

[0058] The steering system 26 is configured to be activated when the trailer 16 and the motor vehicle 10 are reversing, and to be deactivated when the trailer is moving forward. The steering system 26 is configured to activate the actuator 40 when the trailer is reversing, and to deactivate the actuator 40 when the trailer is moving forward to conserve energy. The actuator 40 is powered by the electric battery. When moving forward, the steering wheels 28 remain parallel to the longitudinal axis 36 of the trailer 16.

[0059] According to an alternative of the invention, the actuator 40 is powered by a battery of the motor vehicle 10.

[0060] According to one option, at high speed, for example above 90 km / h, the steering system 26 is configured so as to turn the steering wheels 28 of the trailer in the same direction as those of the motor vehicle. This aspect improves stability, and therefore safety.

[0061] The steering wheels 28 comprise axes of rotation 44. The axes of rotation 44 are horizontal and perpendicular to the vertical steering axes 30. The steering system 26 is configured to obtain an instantaneous center of rotation position 38 of the motor vehicle, notably through communication means. The steering system 26 is configured to control the actuator 40 so that the axes of rotation 44 of the steering wheels 28 intersect at the instantaneous center of rotation 38 according to the angle of inclination 34.

[0062] Figure 3 shows an underside view of a trailer 16, according to one embodiment of the invention. A motor vehicle 10 is shown by its rear bumper, from which the tow hitch 14 protrudes. The motor vehicle 10 and the trailer may correspond to those shown in relation to one of Figures 1 to 2.

[0063] The coupling system 12 includes a coupling hook 14 with a mounting plate 46 fixed to the structure of the motor vehicle 10, a coupling ball 48 (shown in dotted lines), an arched arm 50 physically connecting the coupling ball 48 to the mounting plate 46.

[0064] The chassis 22 of the trailer 16 includes several longitudinal members connected to the axle suspension system. The steering system 26 further includes an actuator 40 and a module 42 for determining the trailer's angle of inclination relative to the motor vehicle 10. The module 42 obtains, by means of communication, reading, or calculation, the angle of inclination between the coupling hook 14 and the coupling head 20. The angle of inclination is determined based on the angular position of the pivoting body relative to the coupling head 20. The steering system 26 is configured to orient the steering wheels 28 according to said angle of inclination via the actuator 40; by means of calculations via a computer.

[0065] The coupling system 12 has a coupling head 20 mounted on the tow ball 48; a vertical pivot axis 52 of the coupling head 20 relative to the tow hook 14 and thus of the trailer relative to the motor vehicle 10. The arched arm 50 includes an angular stop. The coupling system 12 includes a pivoting body 54 about the vertical pivot axis 52 and coupled, i.e., driven by the angular stop. The pivoting body 54 is connected to the coupling head 20.

[0066] Via the actuator 40, the coupling system 12 controls the orientation of the steering wheels 28, and therefore of their axes of rotation 44, so that they intersect at the instantaneous center of rotation of the motor vehicle 10. The calculation is performed based on the angle of inclination. The calculation can be based on average geometric data, or on actual data retrieved from memory, or provided by a user.

[0067] In general, the acquisition module includes an angle sensor, including in particular the pivoting body 54.

[0068] According to one embodiment, the steering system 26 comprises a rack and pinion cross linkage 70 connecting the steering wheels. The cross linkage 70 includes a rod and steering rods. The actuator comprises a pinion motor meshing with the rack. The rack is arranged on a cross bar. The cross bar forms a mechanism for indexing the orientation of the steering wheels relative to each other.

[0069] According to one embodiment of the invention, the steering system 26 is configured so as to maintain the tilt angle via the actuator 40 and the steering wheels 28.

[0070] According to an alternative embodiment of the invention, the steering system is configured to reduce the tilt angle via the actuator and the steering wheels. According to another option, the tilt angle is closed in order to align the trailer with the motor vehicle.

[0071] According to an alternative of the invention, the actuator comprises a cylinder, for example electric or hydraulic.

[0072] Figure 4 shows a steering system 26 for a motor vehicle trailer, according to an embodiment of the invention. The motor vehicle and the trailer may correspond to those shown in relation to one of Figures 1 to 3.

[0073] Generally, the coupling hook 14, in particular the curved arm 50, includes means for preventing rotation. The means for preventing rotation include an angular stop 60. The angular stop 60 includes a projection extending from the curved arm 50.

[0074] The coupling system 12 comprises a pivoting body 54 about the vertical pivot axis 52 and connected to the coupling head 20. The pivoting body 54 includes an insertion slot 56 configured to cooperate with the angular stop 60, such that the arched arm 50 rotates the pivoting body about the vertical pivot axis 52 during its lateral oscillations. The width of the arched arm 50 is equal to the width of the insertion slot 56. Their diameters are equal.

[0075] The coupling system 12 further includes a module 42 for obtaining an angle of inclination between the coupling hook 14 and the coupling head 20, as a function of an angular position of the pivoting body 54 relative to the coupling head 20, or more precisely relative to a flap 32. The interface between the pivoting body 54 and the flap 32 has position sensors to determine the orientation of the pivoting body 54.

[0076] The coupling module 42 comprises a flap 32 pivotally connected to the coupling head 20 along a horizontal pivot axis. The pivoting body 54 pivots inside the flap 32. It is capable of pivoting at least 90°, preferably at least 120°, relative to the flap 32. The flap 32 is a safety flap configured to retain the coupling ball 48 in the coupling head 20.

[0077] The pivoting body 54 is movable within the flap 32. It generally forms a pivoting ring. The ring is slotted to allow the longitudinal insertion of the arched arm 50. The pivoting body 54 also forms a pivoting fork and clamps the arched arm 50. The pivoting fork cooperates with the angular stop 60 to transmit pivoting movements around the vertical pivot axis 52.

[0078] The insertion slot 56 is open at the rear. It is configured to cooperate with the angular stop 60 so that the arched arm 50 drives the pivoting body around the vertical pivot axis 52. The width of the insertion slot 56 is less than the width of the angular stop 60.

[0079] The angular stop 60 comprises a rib 58 projecting on the arched arm 50. The insertion slot 56 is configured to cooperate with the rib 58. The width of the rib 58 is substantially adjusted to the width of the insertion slot 56. The lateral faces of the rib 58 are intended to abut against the internal faces of the insertion slot 56.

[0080] The steering system 26, in particular the input module 42, includes a memory 62 containing geometric data of the motor vehicle and the trailer. The input module 42 also includes a control unit 64. The control unit 64 is configured to calculate the instantaneous center of rotation position based on said geometric data. The control unit 64 calculates a wheel swivel command. guidelines based on the angle of inclination, said setpoint being applied via the actuator.

[0081] The steering system 26, in particular the acquisition module 42, includes means 66 for communicating with the motor vehicle in order to obtain said position of the instantaneous center of rotation. Communication may be via a plug connected to the motor vehicle. Alternatively, communication is carried out by electromagnetic waves.

[0082] The computer 64 is a processor. The processor may comprise one or more programmable electronic microprocessors or microcontrollers. In addition, the processor may comprise a central processing unit (CPU), memory (in addition to or as separate memory as illustrated by reference number 62), and an input / output (I / O) interface through which the processor may receive a plurality of input signals. Such an I / O interface is also configured to generate a plurality of output signals including, but not limited to, those used to control and / or provide data to be displayed.

[0083] Memory 62 is intended for storing data and instructions or code (i.e., software) that can be read and / or written by the processor. The memory may include various forms of non-volatile (i.e., non-transient) memory. Non-volatile memory includes flash memory or read-only memory (ROM), and any type of programmable read-only memory (e.g., PROM, EPROM, EEPROM). The memory optionally includes volatile memory, including random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), and synchronous dynamic random access memory (SDRAM). According to the invention, the memory may be internal to the processor or, alternatively, form a separate component.

[0084] According to an alternative of the invention, the angular stop comprises a vertical groove formed in the arched arm, and in the insertion slot the pivoting body comprises a pin engaged in said vertical groove.

[0085] According to an alternative of the invention, the angular stop comprises a flat.

[0086] According to an alternative of the invention, the arched branch comprises a square profile.

[0087] The invention comprises the combination of all the embodiments illustrated by all the figures.

Claims

Demands

1. Trailer (16) for motor vehicle (10); said trailer (16) comprising: a chassis (22), a coupling device (18) for a motor vehicle (10), said coupling device (18) comprising a coupling head (20) fixed to the chassis (22) and intended to be coupled to a coupling hook (14) of a motor vehicle (10); a steering system (26) with steering wheels (28) pivotally connected relative to the chassis (22); characterized in that the steering system (26) further comprises an actuator (40), a module for obtaining an angle of inclination (34) of the trailer (16) relative to the motor vehicle (10), the steering system (26) being configured to orient the steering wheels (28) according to said angle of inclination (34) via the actuator (40).

2. Trailer (16) according to claim 1, characterized in that the obtaining module (42) comprises a pivoting body (54) about a vertical pivoting axis (52), the pivoting body (54) comprising an insertion slot (56) for receiving the coupling hook (14) of a motor vehicle (10); the pivoting body (54) being configured to be driven in rotation by the coupling hook (14) in order to obtain the angle of inclination (34).

3. Trailer (16) according to claim 2, characterized in that the obtaining module (42) comprises a flap (32) pivotally connected to the coupling head (20) along a horizontal pivot axis; the pivoting body (54) being pivotally mounted relative to said flap (32); preferably, the flap (32) is configured to retain a coupling ball (48) in the coupling head (20).

4. Trailer (16) according to any one of claims 1 to 3, characterized in that the steering system (26) is configured to be activated when the trailer (16) is in reverse, and to be deactivated when the trailer (16) is in forward; preferably, the trailer (16) comprises an electric battery (24) for driving the motor vehicle (10), the electric battery (24) comprising a capacity of at least 5 kWh; more preferably of at least 50 kWh.

5. Trailer (16) according to any one of claims 1 to 4, characterized in that the steering system (26) comprises a transverse linkage (70) rack connecting the steering wheels (28), the actuator (40) comprising a pinion motor engaging the rack.

6. Trailer (16) according to any one of claims 1 to 5, characterized in that the steering wheels (28) comprise axes of rotation (44), the steering system (26) is configured to obtain an instantaneous center of rotation position (38) of the motor vehicle (10); the steering system (26) being configured to control the actuator (40) so that the axes of rotation (44) of the steering wheels (28) intersect at the instantaneous center of rotation (38) according to the angle of inclination (34).

7. Trailer (16) according to claim 6, characterized in that the steering system (26) comprises: a memory (62) with geometric data of motor vehicle (10) and of the trailer (16), a computer (64) configured to calculate the position of instantaneous center of rotation (38) as a function of said geometric data; preferably, the steering system (26) comprises means of communication (66) with the motor vehicle (10) in order to obtain said position of instantaneous center of rotation (38).

8. Coupling system (12) between a trailer (16) and a motor vehicle (10), the coupling system (12) comprising a coupling hook (14) with a mounting plate (46) intended to be fixed to a motor vehicle structure (10), a coupling ball (48), an arched arm (50) connecting the coupling ball (48) to the mounting plate (46); a coupling head (20) intended to be coupled to the coupling ball (48); a vertical pivot axis (52) of the coupling head (20) relative to the coupling hook (14); characterized in that the arched arm (50) comprises an angular stop (60);the coupling system (12) includes a pivoting body (54) about the vertical pivot axis (52) and connected to the coupling head (20), the pivoting body (54) including an insertion slot (56) configured to cooperate with the angular stop (60) so that the arched arm (50) drives the pivoting body (54) around the vertical pivot axis (52); the coupling system (12) further includes a module for obtaining an angle of inclination (34) between the coupling hook (14) and the coupling head (20), depending on an angular position of the pivoting body (54) relative to the coupling head (20).

9. Coupling system (12) according to claim 8, characterized in that the angular stop (60) comprises a rib (58) projecting on the arched arm (50); the insertion slot (56) being configured to cooperate with the rib (58).

10. Coupling system (12) according to any one of claims 8 to 9, characterized in that the coupling system includes an actuator (40) configured to control a steering wheel orientation (28) of the trailer (16) as a function of the tilt angle (34).

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