Patent Application
20230331300
The present invention relates to the technical field of devices used in a workshop to ensure, among other things, the adjustment of the parallelism of the steered wheels of a vehicle or, more generally, the adjustment of the vehicle running gear or its trajectory.
In order to ensure the safe use of a motor vehicle, it is necessary to regularly adjust the running gear of the latter. In addition, proper adjustment contributes to guaranteeing wear of the tires that is as even as possible as well as ensuring the correct operation of the active and passive safety devices integrated into the vehicle.
On a motor vehicle, the adjustment of the wheels is generally done by placing the vehicle on a car lift so as to be able to easily access the adjusting members of the running gear, namely the systems for connecting the wheels of the vehicle to the chassis. When adjusting the parallelism of the steered wheels, the operator can unintentionally slightly modify the orientation of the steered wheels, which can induce an adjustment bias and in particular a slight shift between the theoretical position of the steering wheel normally corresponding to a rectilinear trajectory and the actual position of the steering wheel actually corresponding to a rectilinear trajectory. However, this bias can be troublesome when the vehicle includes sensor systems which analyze the trajectory of the vehicle as a function of the position or the degree of rotation of the steering wheel. In order to avoid this bias, the operator making the vehicle settings, in particular that of the parallelism, must check at several stages of the adjustment action that the steering wheel is correctly placed in the neutral position corresponding to a straight trajectory when the steered wheels are parallel to each other in an orientation corresponding to a rectilinear trajectory of the vehicle. However, to place the steering wheel in the neutral position or check its placement in this neutral position, it is necessary to get seated in the driving position in the driver's seat in order to have the visual cues necessary for the check. However, when the vehicle is on a lift, on the one hand, it is difficult to quickly access the driving position and, on the other hand, the methods of locking the steering wheel necessary for the adjustments make access to the driver's seat almost impossible.
In order to respond to this problem, a steering wheel positioning aid device has been proposed comprising a plate intended to be fixed on the steering wheel and equipped with a spirit level giving a horizontal reference. When using the device, the operator sits in the driving position and turns the steering wheel so that the bubble is in a position corresponding to horizontality. This device has two drawbacks. First of all, it imposes as a prerequisite that the horizontality corresponds to the neutral position of the steering wheel. Then, it requires the operator to be perfectly in front of the level in order to avoid reading errors induced by parallax defects so that the operator can only carry out the check while being in the driving position.
It has also been proposed by a patent application DE102008008858 a system comprising a graduated disc intended to be fixed on the steering wheel and associated with a lamp fixed or placed on the dashboard projecting a luminous index on the graduated disc. Such a device makes it possible to monitor and measure the amplitude of rotation of the steering wheel according to the drift of the front gear and to ensure a control of the dynamic relationship between the rotation of the steering wheel and the variation of the steering angle but does not make it possible to know or control the neutral position of the steering wheel as is necessary to adjust in particular the parallelism of the steering gear, generally the front gear. In fact, there is nothing to guarantee, when fixing the graduated disc on the steering wheel, that the 0 of the disc corresponds to the neutral position of said steering wheel.
An application DE102013021475 proposed an automated system for adjusting the chassis and the steering system of a vehicle at the end of the production line. This system which is intended to operate without human intervention, aims to calibrate the steering angle sensors. To this end, the system comprises a device for projecting onto a surface of the steering wheel a temporally and/or spatially coded pattern adapted to be analyzed by an electronic image recognition system which, depending on the variations in shape of the pattern, calculates the angle of rotation of the steering wheel and sends it to a vehicle sensor calibration system. Such an automated system is particularly expensive so that it is not suitable for use in a workshop and cannot be implemented without a complex and sophisticated optical and computerized shape recognition system, not to mention the fact that it makes the working space inaccessible for placing a steering wheel lock or a brake pedal lock, and that it is incompatible with any vehicle lifting process where the chassis adjustment intervention cannot be carried out from below the vehicle.
It therefore appeared the need for means making it possible to control the placement of the steering wheel in the neutral position without necessarily being seated in the driver's seat in the driving position and without the implementation of heavy computer resources. Another object of the invention is to provide a simple, easy to implement, and reliable system for controlling the placement of the steering wheel of a vehicle in the neutral position.
In order to achieve this objective, the invention relates to a device for assisting the placement in a neutral position of a rectilinear trajectory of the steering wheel of a vehicle, this device comprising a light source configured to project at least one light pattern defining at least one alignment direction and fixing means adapted to allow temporary fixing of the device on the vehicle so that the light source is facing or situated in a plane facing the steering wheel so that the light pattern is projected at least inside the circle delimited by the steering wheel.
Advantageously, the projection of the light alignment pattern inside the circle delimited by the steering wheel allows the operator to check the placement in the neutral position of the steering wheel without being seated in the driver's seat. Indeed, thanks to the invention the operator can check from outside the vehicle that the steering wheel is aligned with the projected light alignment pattern, without parallax error. In the event of a positioning fault, the operator can also maneuver the steering wheel from outside the vehicle to align the steering wheel with the reference pattern.
According to one characteristic of the invention, the fixing means comprise an elongated crosspiece on which the light source is fixed and which comprises at each of its two ends at least one finger forming an acute angle with the longitudinal direction of the crosspiece, the at least one of the two fingers being movable in longitudinal translation relative to the crosspiece and being associated with clamping means configured to allow gripping with the two fingers a part of the vehicle so as to fix the device on the latter. Such fixing means make it possible to easily fix the device to an element of the vehicle other than the steering wheel and which is in a fixed position with respect to the latter.
According to a variant of this characteristic, the distance between the two opposite fingers is greater than or equal to 0.9 m. According to another variant of this characteristic, the crosspiece has a length greater than or equal to 0.6 m. These variants advantageously make it possible to fix the device according to the invention to the bodywork of the vehicle and for example on or between the uprights of the two front or rear doors, the crosspiece and the light source being inside the vehicle. Such a method of fixing makes it possible to use the body or the body of the vehicle as a reference for positioning the device according to the invention. The device according to the invention can then be fixed to the body of the vehicle with the doors being open or closed—the windows being open.
According to a variant of this characteristic, the two fingers are movable in longitudinal translation with respect to the crosspiece and each one is associated with clamping means providing elastic return of the corresponding finger towards the crosspiece or the center of the crosspiece.
According to yet another variant of this characteristic, the light source is movable along the crosspiece so as to adjust the longitudinal position of the light source relative to the crosspiece. Advantageously, this variant makes it possible to place the light source substantially opposite the steering wheel.
According to another characteristic of the invention, the light pattern comprises at least one line segment.
According to yet another characteristic of the invention, the light source comprises at least one laser light source suitable for projecting at least a substantially horizontal rectilinear light line.
According to a variant of this characteristic, the light source is a laser diode suitable for projecting a cross formed from two orthogonal straight lines.
Of course, the different characteristics, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or exclusive of each other.
In addition, various other characteristics of the invention emerge from the appended description made with reference to the drawings which illustrate non-limiting forms of embodiment of the invention and where:
The geometry adjustment or pre-geometry operation consists in adjusting/checking the components of the running gear of a vehicle following a fault observed in trajectory and/or dynamic behavior.
This operation is either mandated by expertise, in the context of an accident and repaired vehicle, or by customer complaint, or by simple mechanical “logic” during the repair of a vehicle (for example following a mechanical operation which requires the removal/refitting/replacement of the engine subframe or the removal/refitting/replacement of an axle) or even linked to the replacement of certain worn parts such as the steering ball joints, axial ball joints, silent support blocks (defects typically noted by a technical inspection).
A badly adjusted or misaligned running gear means random vehicle trajectory, degraded handling, deviant braking, premature wear of the vehicle's rubber or tires, excessive shifting sometimes leading to a return visit to the technical inspection. A few isolated cases have also shown that the deactivation of the ESP system may be due to a heading drift. Dysfunction of the running gear or its incorrect adjustment can also induce a fault in other safety systems (active or passive) fitted to the vehicle (adaptive cruise control, white line crossing warning/lane keeping assistance, automatic emergency braking, . . . ).
This running gear adjustment is carried out in the workshop and requires specific equipment with a human worker trained in the operation but also in the equipment used.
The vehicle is placed on a lift, typically a scissor lift where the vehicle rests on its wheels. This lift is fitted with free plates for the bearing points of the wheels so as not to apply any stress on the running gear, either axial or lateral. Depending on the technology of the material used, the vehicle can also be placed on an arm lift.
There are a few preliminary steps specific to the vehicle which will not be described here, such as checking the pressure and condition of the tires, checking the loads transported unevenly distributed in the vehicle (especially in the case of lifting by a platform lift).
The operator then installs the specific geo equipment on the vehicle and/or on the lift in order to begin the work.
The detailed points of the operation will not be described because each geometry or control device for the running gear has its own implementation methods, but among all of these methods, one is common to all scenarios, that is the placement of the steering wheel V in a neutral position N.
In fact, after reading the pivot angle, caster, deviations and other characteristics, before making the necessary adjustments resulting from these preliminary measurements, the operator must hold the steering wheel of the vehicle in a very precise position, and it is in this step that device according to the invention intervenes.
Indeed, regardless of the adjustment methods or equipment used, it is always imperative to adjust a straight steering wheel position (visually, the angle of rotation given to the steering wheel must be that of a steering wheel which keeps the trajectory perfectly straight of the vehicle on a straight road, i.e. a 0 degree angle or neutral position of the steering wheel). Then, this position must be blocked with the tool provided by the equipment manufacturer of the geometry device.
As with any intervention in the workshop, even using machines, tools, instruments, there is human intervention to set up these tools or to interpret the results given by these tools. Here, in the chain of running gear adjustment operations, all the steps which the operator must carry out will not be listed.
However, in all cases, the operator must pay particular attention to a crucial point which determines the entire sequence of operations, that means the “correct” sequence of operations, because at the end of the work, during the dynamic test of the vehicle, if an anomaly is observed (and this is not so rare), he could always ask the question: was the steering wheel really straight or in the neutral position, as illustrated in
With regard to positioning the steering wheel V straight (i.e. in neutral position N) and the use of the steering wheel lock B, there is no machine or mechanical device that could guide the operator in this task. The operation therefore results from an approximation which depends on the operator. In addition, the operation of locking the steering wheel in the neutral position cannot be carried out in the driving position, on the driver's seat, because the steering wheel lock B and possibly a brake pedal press, once placed, will prevent the operator from getting out of the vehicle or, if he is in the driving position, he will not be able to get out at the risk of varying the position of the steering wheel that he has just adjusted.
Therefore, as is commonly practiced in a workshop, this operation of adjusting and fitting the steering wheel lock is done from outside the vehicle, either with the door open, or with the door closed with the driver's window down. In any case, it is impossible for the operator to be facing the steering wheel and there is, when adjusting by eye, a parallax error as shown in
In this step of positioning the steering wheel V in neutral position N, the operator intervenes from the outside or at best from the door sill of the vehicle (door open) with, a fortiori, this error of remanent interpretation Δ due to this parallax. Even if he tries to free himself from it by contorting himself, objectively he will never find the position of the driver sitting on his seat, occupying the natural driving position, facing the driving position. He will therefore make a steering wheel positioning error.
The invention therefore aims at avoiding this error by means of the device, according to the invention, for aiding placement in the neutral position of the straight trajectory of the steering wheel of a vehicle as illustrated in
In the present case, the fixing means 3 of the device are formed by a self-tightening telescopic bar adapted to cling to the structure of the vehicle as more particularly illustrated in detail in
In addition, according to the illustrated example, the light source 2 is fitted to the crosspiece by means of a cradle 10 which itself is fixed to the crosspiece 4 via a slider 11 which is movable in translation along the crosspiece 4. The cradle 10 is connected to the slider by a pivot connection with axis A1 substantially perpendicular to the direction of extension of the crosspiece 4. Finally, the light source 2 is connected to the cradle 10 by a pivot connection with axis A2 perpendicular to axis A1. This mode of adaptation of the light source on the crosspiece 4, by means of a system whose kinematics is similar to a universal joint, allows adjustment of the position and orientation of the light source 2 relative to the projection area of the pattern M.
It should be noted that, according to the invention, the crosspiece may comprise several segments sliding one inside the other while being associated with means for locking their relative translation. This embodiment makes it possible to adjust the length of the crosspiece 4 independently of the position of the clamping fingers with respect to said crosspiece, and, therefore, to adapt the length of the crosspiece to the dimensions of the bodywork element(s) to which the device according to the invention is hooked or fixed.
According to the illustrated example, the luminous pattern is a luminous cross projected on the target surface to initially visualize a horizontal virtual line in the passenger compartment. In order to increase the efficiency of the system, this cross is produced by a laser which points the target whatever its material or color (including black) and whatever its shape, flat or complex. It constitutes a real level of light in the passenger compartment and crosses it from side to side and via the steering wheel, the desired level for the latter. Due to the projection made on the surfaces of the steering wheel, even when viewed from the outside, there can no longer be a problem of visual interpretation and there is no longer any parallax error.
It should be noted that according to one embodiment of the invention, the light source is fixed or linked to the crosspiece so as to be movable in translation relative to the crosspiece while being able to be immobilized thereon. This embodiment then makes it possible to adjust the longitudinal position of the light source and, for example, makes it possible to place it exactly in front of the steering wheel.
Also, to perfect the use, in addition to the properties of the laser beam, the device further comprises an auxiliary light source capable of illuminating the area around the target in order to allow the user to effectively visualize the near environment in which he must operate.
According to the illustrated example, the device in accordance with the invention is suitable for:
The best possible placement is that of the support from the roof of the car passing through the openings of the vehicle because they are perfectly symmetrical and guarantee a positioning base perfectly parallel to the dashboard. The rearward position of the system makes it possible, thanks to the opening angle of the laser lens, to project a light trace whose width then becomes maximum and covers the entire width of the dashboard. The crosspiece of the device, which can then be called a “ruler or roof bar” formed by the self-tightening telescopic bar described above, is clamped or hooked onto the structure of the vehicle as shown in
Of course, various other embodiments of the invention can be contemplated within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003030 | Mar 2020 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/052559 | 3/28/2021 | WO |
