vehicle equipped with optimized steering of two deflectors placed in front of the front wheels

Abstract

The invention relates to a vehicle comprising two front wheels (12, 13) and two rigid deflectors (1, 2) positioned in front of the two front wheels (12, 13), each being rotatably mounted between an active position in which it protrudes under the vehicle in front of a front wheel (12, 13) extending in a vertical and transverse plane YZ of the vehicle, and an inactive position in which it is stored within the vehicle. The vehicle includes a braking system (10) comprising a brake booster (18) and a brake pedal (11).According to the invention, the vehicle includes an actuation mechanism for the two deflectors (1, 2) based on an actuation circuit (51) originating from the brake booster (18) and terminating in an actuator (52) which is connected to the two deflectors (1, 2). Pressing the brake pedal (11) simultaneously induces a braking phase of the vehicle and activates the actuator (52), causing the two deflectors (1, 2) to pivot until they reach the inactive position. Figure 4 for the abbreviated version.

Description

Title of the invention: vehicle equipped with optimized control of two deflectors placed in front of the front wheels

[0001] The present invention relates to a vehicle equipped with optimized control of two deflectors placed in front of the front wheels. We assume that a vehicle according to the invention conventionally comprises front wheels and rear wheels.

[0002] In order to better understand the positioning of the different parts involved in a vehicle according to the invention, the description is made with reference to a direct orthonormal frame XYZ in which X is a front-to-back longitudinal axis of the vehicle oriented towards the rear, Y is a transverse axis oriented towards the right of the vehicle and Z is a vertical axis directed upwards.

[0003] Currently, some motor vehicles are equipped with two deflectors, each positioned in front of a front wheel. Each deflector is a rigid, thin flap extending in a transverse and vertical plane YZ of the vehicle. These flaps, generally attached to a front bumper diffuser, are designed to deflect the air in front of the vehicle during its movement, preventing it from directly impacting the front wheels. In this way, these deflectors improve the vehicle's aerodynamics, resulting in: - reduced fuel consumption, - reduced CO2 emissions, - increased vehicle range.

[0004] It was observed that these deflectors have little influence when the vehicle is traveling at speeds of 70 km / h or less, but play a decisive role in fuel consumption when the vehicle is traveling at speeds above 70 km / h. To meet this specific need for deflector implementation, it was considered possible to control the rotation of these deflectors between an active, deployed position and an inactive, retracted position. To achieve this, each deflector is mounted for rotation around a transverse Y and horizontal axis of rotation of the vehicle, and can thus pivot around said axis from the active position, in which it protrudes under the vehicle, extending in a transverse and vertical YZ plane of the vehicle, to the inactive position, in which it extends in a horizontal plane, folded against a horizontal wall of the vehicle.These deflectors are automatically controlled according to a vehicle speed threshold, by means of a central processing unit that is on board the vehicle. When the input data from this central processing unit indicates that the deflectors should be placed in one of the two previous positions, the said central processing unit activates an electric motor that is associated with the deflector and which... causes the deflector to move into the desired position.

[0005] However, it turns out that a control of these deflectors based solely on the speed of the vehicle to be positioned relative to a threshold speed is not sufficiently precise, and that ultimately, these deflectors play a major role regardless of the speed of the vehicle and that their influence is negligible during vehicle braking phases.

[0006] A vehicle according to the invention is equipped with a control mechanism for the two flaps allowing said two flaps to be systematically placed in the active position during driving phases of said vehicle, and in the inactive position during braking phases of said vehicle.

[0007] The invention relates to a vehicle comprising two front wheels, a front bumper diffuser and two rigid deflectors placed in front of the two front wheels, each being mounted in rotation on the bumper diffuser between an active position in which it protrudes under the vehicle in front of a front wheel, extending in a vertical and transverse plane YZ of the vehicle, and an inactive position in which it extends horizontally, being stored against the diffuser, said vehicle comprising a braking system including a servo brake, a braking circuit including brake fluid, and a brake pedal.

[0008] According to the invention, the vehicle includes an actuation mechanism for the two deflectors based on an actuation circuit in which the brake fluid circulates and on an actuator, said actuation circuit originating on the brake booster and leading to the actuator which is connected to the two deflectors, and, during a phase of vehicle driving, the deflectors are automatically placed in the active position, pressure on the brake pedal causing both a braking phase of the vehicle and an activation of the actuator causing the two deflectors to pivot to the inactive position.The unique feature of a vehicle according to the invention is that, during its rolling motion, the deflectors are always in the active position, diverting the air in front of the vehicle to its sides to improve its aerodynamics. During braking, they automatically return to the inactive position, where they have no effect on the air in front of the vehicle. Thus, during each braking phase, since the vehicle's aerodynamics no longer need to be optimized, the deflectors automatically retract. It should be noted that the axis of rotation of each of the two reflectors extends along a transverse Y-axis of the vehicle.In a vehicle according to the invention, pressure on the brake pedal causes a displacement of brake fluid, both in the braking circuit and in the actuation circuit of the two deflectors, reflecting the fact that at each braking phase the deflectors retract.

[0009] According to one possible feature of the invention, the two deflectors are mounted Mounted on a single cylindrical actuating rod extending along a transverse Y-axis of the vehicle, the actuator, when activated by pressure on the brake pedal, causes the actuating rod to rotate around its axis of revolution, thus placing the two deflectors in the active position. In this way, the actuator is configured to cause a rotation of a given angular amplitude of the actuating rod connecting the two deflectors. Using a single actuating rod for both deflectors simplifies the deflector actuation mechanism and reduces potential sources of failure by minimizing the number of parts involved in the actuation process.

[0010] According to one possible embodiment of the invention, the two deflectors are positioned at the two ends of the actuating rod under consideration, along a longitudinal axis of said actuating rod, with the actuator acting on a central area of ​​this actuating rod. Thanks to this configuration, the actuation mechanism of the two deflectors is balanced, limiting the risk of drift over time from one deflector operating more effectively at the expense of the other. Advantageously, the length of the actuating rod connecting the central area to each deflector is constant.

[0011] According to one possible feature of the invention, the actuator is a single-acting cylinder having a body that receives the brake fluid, and a sliding rod housed within said body. One free end of the sliding rod is connected to a secondary shaft that is fixed perpendicular to the actuating rod, such that a translational displacement of the sliding rod within the body, caused by pressure applied to the brake pedal, results in a displacement of the secondary shaft, which in turn causes the actuating rod to rotate about its axis of revolution. In this configuration, a translational displacement of the sliding rod within the cylinder body results in a rotational displacement of the secondary shaft around the actuating rod, causing the actuating rod to rotate about its axis of revolution.Applying pressure to the brake pedal will first cause brake fluid to move through the actuation circuit and then into the body of the single-acting cylinder, moving the sliding rod in the body in translation to generate a rotation of the actuating rod in a direction that will favor a movement of the deflectors towards the inactive position.

[0012] According to a possible feature of the invention, the free end of the sliding rod is mounted articulated on the secondary axis.

[0013] According to a possible feature of the invention, the actuation circuit includes a flow limiter placed between the servobrake and the actuator, the flow limiter This allows for a delay between the moment the brake pedal is released and the moment the deflectors return to their active position. Schematically, the principle of such a limiter is to have a supply and a return line for brake fluid, such that the cross-section of the return line is smaller than that of the supply line. The cross-section of the supply line is sized so that it does not influence the flow of brake fluid to the cylinder. In this way, after the driver applies pressure to the brake pedal to slow the vehicle and place the deflectors in the inactive position, when the pressure on the brake pedal is released, the deflectors will not instantly return to their active position. The flow limiter will, in effect, delay the repositioning of these deflectors to the active position.Thus, for example, in the specific case where the vehicle needs to be temporarily braked when approaching a speed bump, if the driver wishes to cross the bump, they will release the brake pedal before the deflectors have instantly returned to their active position due to the flow limiter. The vehicle will then cross the speed bump while the deflectors are in the inactive position, and therefore without risk of damaging them.

[0014] According to a possible feature of the invention, the flow limiter is associated with a mechanical retarder which has been previously dimensioned to allow a repositioning of the deflectors in the active position after a given period, after a release of the brake pedal.

[0015] According to a possible feature of the invention, a thermostatic valve is fixed to the servobrake, the actuation circuit originating on this thermostatic valve, said electrostatic valve preventing any return of brake fluid to the servobrake if the temperature of said brake fluid has reached a threshold value, maintaining the deflectors in the inactive position.

[0016] According to one possible feature of the invention, each deflector is flat and has a rectangular shape, said deflector moving from the active position to the inactive position and vice versa by means of a 90° rotation. These deflectors can be likened to lightweight and thin shutters that can move easily, without requiring excessive actuation energy.

[0017] The invention also relates to a method of actuating the two deflectors of a vehicle according to the invention, when said two deflectors are in an active position.

[0018] According to the invention, the process comprises the following steps: -a step of applying pressure to the brake pedal for a fairly long period, causing both a braking phase of the vehicle and a rotation phase of the deflectors until each reaches the inactive position, -a step of releasing the brake pedal causing the deflectors to rotate in the opposite direction until they reach the active position.

[0019] The principle of such a method is that each time the brake pedal is pressed for a sufficiently long time, the flaps automatically return to the inactive position, and each time the brake pedal is released, the flaps return to their active position. There is no intermediate position between the active and inactive positions. The term "sufficiently long time" means "time exceeding a predefined threshold value."

[0020] A vehicle according to the invention has the advantage of having deflectors placed in front of the front wheels, the position of which is adjustable solely according to the position of the brake pedal: In this way, the brake pedal has a dual action: -to ensure a braking phase of the vehicle, -cause the deflectors to be stored in the inactive position.

[0021] It follows that the deflectors are deployed in the active position only when needed, that is, during all phases of vehicle operation not involving braking. A vehicle according to the invention also has the advantage of including an actuation mechanism for the two deflectors that is judiciously designed within the vehicle, based on an existing braking circuit. In this way, the actuation mechanism for these deflectors did not have to be completely reinvented.

[0022] A detailed description of a preferred embodiment of a vehicle according to the invention is given below, with reference to the following figures:

[0023] [Fig-1] Fig. 1 is a schematic perspective view of a vehicle according to the invention showing the location of the deflectors,

[0024] [Fig.2] Fig.2 is a schematic perspective view of a braking system of a state-of-the-art vehicle,

[0025] [Fig.3] Fig.3 is a schematic perspective view of a braking system and of a mechanism for actuating the two deflectors of a vehicle according to the invention, the two deflectors being in the active position,

[0026] [Fig.4] [Fig.4] is the schematic view of [Fig.3], the two deflectors being in the inactive position.

[0027] Referring to [Fig. 1], certain motor vehicles are equipped with two deflectors 1, 2, each positioned in front of a front wheel 3. Each of said deflectors 1, 2 is in the form of a rigid, thin flap, generally having a rectangular outline. These deflectors 1, 2 extend in a transverse and vertical plane YZ of the vehicle. These deflectors 1, 2, which are generally attached to a front bumper diffuser 4, are intended to deflect the air in front of the vehicle during a during the rolling phase of the vehicle, so that this air does not directly impact the front wheels 3 placed just behind the said deflectors 1, 2. In this way, these deflectors 1,2 improve the aerodynamics of the vehicle with the main consequences being: -a reduction in the fuel consumption of said vehicle, -a reduction in the emission of CO2 particles, -an increase in the range of the vehicle.

[0028] However, it was observed that these deflectors 1, 2 were not always useful, regardless of the vehicle's operating phase. Therefore, one solution was to mount each of the two deflectors 1, 2 in rotation around an axis of rotation fixed to the bumper diffuser 4, and extending along a transverse axis Y of the vehicle. In this way, each deflector 1, 2 is mounted in rotation on the diffuser 4, between an active position in which it extends under the vehicle in a vertical and transverse plane YZ of the vehicle, and an inactive position in which it is stored against a wall of the bumper diffuser 4, extending in a horizontal plane. Each deflector 1, 2 thus moves from one position to the other by means of a 90° rotation.Software from a central processing unit embedded in the vehicle then controls the movement of these deflectors 1, 2 between the active and inactive positions, according to the needs encountered, related to the different phases of vehicle use and in particular to its speed.

[0029] Following this initial observation, which led to the conclusion that the deflectors 1, 2 were not always useful regardless of the vehicle's operating phase, it was found that these deflectors 1, 2 were simply not useful during the vehicle's braking phases. Rather than reprogramming the central processing unit's software to place the two deflectors 1, 2 in the inactive position during each braking phase, the present invention consists of directly indexing the actuation mechanism of the two deflectors 1, 2 to the vehicle's braking system 10. In this way, pressure applied to a brake pedal 11 of a vehicle according to the invention will have a dual action: -to trigger a braking phase of the vehicle, -move deflectors 1, 2 until they reach the inactive position.

[0030] With reference to [Fig. 2], a vehicle generally comprises two front wheels 12, 13 and two rear wheels 14, 15, as well as a braking system 10, including the brake pedal 11, and a brake booster 18. The braking system 10 also includes a front circuit 16 for circulating brake fluid and a rear circuit 17 for circulating brake fluid, the brake fluid being the same in said front circuit 16 and said rear circuit 17. Schematically, the front brake fluid circuit 16 includes a component connecting the brake booster 18 to a braking element 19 acting on a front wheel 12, 13 and another component connecting the The brake booster 18 is connected to a braking element 20 acting on the other front wheel 12, 13. These two braking elements 19, 20 can, for example, be brake discs. Similarly, and schematically, the rear brake fluid circulation circuit 17 comprises a component connecting the brake booster 18 to a braking element 21 acting on a rear wheel 14, 15 and another component connecting the brake booster 18 to a braking element 22 acting on the other rear wheel 14, 15. These two braking elements can, for example, be brake shoes. Pressing the brake pedal 11, which interacts with the brake booster 18, causes the brake fluid to move in the front circuit 16 and the rear circuit 17, activating the various braking elements 19, 20, 21, 22 which tightly grip the various wheels 12, 13, 14, 15 to ensure braking of the vehicle.Releasing the brake pedal 11 instantly stops the vehicle's braking, allowing it to then roll freely.

[0031] Within the framework of the present invention, the braking system, which is already well known on existing vehicles, is described in summary form, without going into details of operation.

[0032] With reference to Figures 3 and 4, the actuation mechanism 50 for the deflectors 1, 2 of a vehicle according to the invention is directly grafted onto the braking system 10 of said vehicle. This actuation mechanism 50 comprises an actuation circuit 51, and an actuator 52 located upstream of the two deflectors 1, 2.

[0033] For a vehicle according to the invention, the two deflectors 1, 2 are attached to an actuating rod 53 extending along a transverse axis Y of the vehicle. This actuating rod 53 is cylindrical and elongated, and the two deflectors 1, 3 are attached to the two ends of this actuating rod 53 considered along a longitudinal axis of said actuating rod 53, without protruding from the actuating rod. A secondary axis 54 in the form of a straight cylindrical rod is fixed in the middle of the actuating rod 53 so as to extend perpendicularly to it. There is no possibility of movement between the two deflectors 1, 2 and the actuating rod 53, nor between the secondary axis 54 and said actuating rod 53. It should be noted that the actuating rod 53 is straight.

[0034] The actuation circuit 51 originates on the brake booster 18 and terminates in the actuator 52. This actuation circuit 51 is traversed by brake fluid, and the actuator 52 consists of a single-acting cylinder. This single-acting cylinder 52 comprises a hollow, cylindrical body 55 in which a sliding rod 56, preferably cylindrical in shape, is placed. The body 55 is delimited by a cylindrical side wall 55 and by a flat, circular bottom 57. The sliding rod 56 is mounted in the hollow body 55 by means of a pre-stressed return element 59, such as, for example, a coil spring, which tends by default to repel said rod. sliding rod 56, from the bottom 57 of the body 55. The length of the sliding rod 56 is greater than that of the body 55, so that said sliding rod 56 emerges from said body 55 when it is in contact with the bottom 57 of said body 55. The sliding rod 56 thus has a first end which is located opposite the bottom 57 of the body 55, and a second end which emerges from said body 55 and which is hinged on the secondary axis 54 which is fixed to the actuating rod 53. The first end and the second end mentioned above are to be considered with respect to a longitudinal axis of the sliding rod 56.

[0035] Referring to [Fig. 3], when the vehicle is in motion and no pressure is exerted on the brake pedal 11, the deflectors 1, 2 are in the active position in which they extend in a transverse and vertical plane YZ of the vehicle. They can thus deflect the air in front of the vehicle and thereby improve its aerodynamics.

[0036] Referring to [Fig.4], when the driver applies pressure to the brake pedal 11 while the vehicle is in motion, two simultaneous actions are generated: -a conventional braking phase of the vehicle in which each brake element 19, 20, 21, 22 exerts pressure on the relevant wheel 12, 13, 14, 15, -a rotation of the deflectors 1, 2 which thus pass from the active position to the inactive position for which they are stored along the vehicle and no longer perform any function of deflecting the air.

[0037] The method for switching the deflectors 1, 2 from the active position to the inactive position follows the following steps: -a step of applying pressure with the foot on the brake pedal 11 which will cause a displacement of the brake fluid circulating in the actuation circuit 51, -a step of brake fluid inflow into the body 55 of the single-acting cylinder 52, -a step of movement of the sliding rod 56 towards the bottom 57 of the body 55 under the effect of the inflow of brake fluid into said body, said movement being achieved by overcoming the force produced by default by the pre-stressed return element 59 which naturally tends to push the sliding rod 56 away from the bottom 57, -a step of rotating the secondary shaft 54 ​​which is fixed in an articulated manner to the sliding rod 56, this rotation taking place around the actuating rod 53 which then pivots around its axis of revolution, -a step of simultaneous pivoting of the two deflectors 1, 2 which then reach the inactive position.

[0038] As long as the brake pedal 11 remains depressed, the deflectors 1, 2 remain in the inactive position. Releasing the brake pedal 11 allows both deflectors 1, 2 to instantly return to the active position, the steps of the following process as previously described, taking place in the opposite direction: part of the brake fluid comes out of the body 55 of the single-acting cylinder 52, allowing the pre-stressed element 59 to bring the sliding rod 56 back to the bottom of the body 55, this movement of the sliding rod 56 causing the secondary axis 54 to rotate in the opposite direction, which in turn causes the actuating rod 53 to rotate in the opposite direction around its axis of revolution.

[0039] The actuation circuit 51 is equipped with a flow limiter 60 located upstream of the actuator 52, between the brake booster 18 and said actuator 52, to delay the instantaneous repositioning of the two deflectors 1, 2 in the active position when the driver releases pressure on the brake pedal 11. Schematically, the principle of such a limiter 60 is to have a supply and a return brake fluid line, such that the cross-sectional area of ​​the return line is smaller than that of the supply line. The cross-sectional area of ​​the supply line is dimensioned in such a way that it does not influence the flow of brake fluid to the cylinder. Thus, for example, in the particular case where the vehicle must be temporarily braked when approaching a speed bump.When the driver decides to go over the speed bump, they will release the brake pedal before the deflectors have instantly returned to their active position thanks to the flow limiter. The vehicle will then be able to go over the speed bump while the deflectors are in the inactive position, thus preventing any risk of damage to them.

[0040] During vehicle operation, the brake fluid may overheat and reach an excessively high temperature. A thermostatic valve 61 is then attached to the brake booster 18 so that the actuation circuit 51 originates from this thermostatic valve 61. This electrostatic valve 61 prevents any return of brake fluid to the brake booster 18 if the temperature of said brake fluid has reached a threshold value, thus maintaining the deflectors 1, 2 in the inactive position.

Claims

Demands

1. A vehicle comprising two front wheels (12, 13), a front bumper diffuser (4) and two rigid deflectors (1, 2) positioned in front of the two front wheels (12, 13), each being rotatably mounted on the bumper diffuser (4) between an active position in which it protrudes under the vehicle in front of a front wheel (12, 13) extending in a vertical and transverse plane YZ of the vehicle, and an inactive position in which it extends horizontally, being stored against the diffuser (4), said vehicle comprising a braking system (10) including a brake booster (18), a braking circuit (16, 17) including brake fluid, and a brake pedal (11), characterized in that it comprises a mechanism for actuating the two deflectors (1, 2) based on an actuation circuit (51) through which the brake fluid circulates and on an actuator (52),said actuation circuit (51) originating on the brake booster (18) and leading to the actuator (52) which is connected to the two deflectors (1, 2), and in that during a vehicle driving phase the deflectors (1, 2) are automatically placed in the active position, pressure on the brake pedal (11) causing both a braking phase of the vehicle and an activation of the actuator (52) resulting in a pivoting of the two deflectors (1, 2) until they reach the inactive position.

2. Vehicle according to claim 1, characterized in that the two deflectors (1, 2) are mounted on the same cylindrical actuating rod (53) extending along a transverse axis Y of the vehicle and are fixed on said actuating rod (53), and in that the actuator (52) when activated by pressure on the brake pedal (11), causes this actuating rod (53) to rotate around its axis of revolution to place the two deflectors (1,2) in the active position.

3. Vehicle according to claim 2, characterized in that the two deflectors (1,2) are placed at the two ends of the actuating rod (53) considered along a longitudinal axis of said actuating rod (53), and in that the actuator (53) acts on a central area of ​​this actuating rod (53).

4. A vehicle according to any one of claims 2 or 3, characterized in that the actuator is a single-acting cylinder (52) having a body (55) receiving the brake fluid, and a sliding rod (56) which is housed in said body (55), and in that a free end of the sliding rod (56) is connected to a secondary axis (54) which is fixed to the actuating rod (53) by being perpendicular to it, so that a translational displacement of the sliding rod (56) in the body (55) generated by a pressure exerted on the brake pedal (11), causes a displacement of the secondary axis (54) which then causes a rotation of the actuating rod (53) around its axis of revolution.

5. Vehicle according to claim 4, characterized in that the free end of the sliding rod (56) is mounted articulated on the secondary axis (54).

6. Vehicle according to any one of claims 1 to 5, characterized in that the actuation circuit (51) includes a flow limiter (60) placed between the brake booster (18) and the actuator (52), and in that the flow limiter (60) makes it possible to introduce a delay between the moment when the brake pedal (11) is released and the moment when the deflectors (1, 2) return to the active position.

7. Vehicle according to claim 6, characterized in that the flow limiter (60) is associated with a mechanical retarder which has been previously dimensioned to allow a repositioning of the deflectors (1,2) in the active position after a given period, after a release of the brake pedal (11).

8. Vehicle according to any one of claims 1 to 7, characterized in that a thermostatic valve (61) is fixed to the brake booster (18), and in that the actuation circuit (51) originates on this thermostatic valve (61), said thermostatic valve (61) preventing any return of brake fluid to the brake booster (18) if the temperature of said brake fluid has reached a threshold value, maintaining the deflectors (1, 2) in the inactive position.

9. Vehicle according to any one of claims 1 to 8, characterized in that each deflector (1,2) is flat and has a rectangular shape, and in that said deflector (1,2) moves from the active position to the inactive position and vice versa by means of a 90° rotation.

10. A method for actuating the two deflectors (1, 2) of a vehicle according to any one of claims 1 to 9 when said two deflectors (1, 2) are in an active position, characterized in that it comprises the following steps: - a step of pressing the brake pedal (11) for a sufficiently long period, causing both a braking phase of the vehicle and a phase of rotating the deflectors (1, 2) until each reaches the inactive position, -a step of releasing the brake pedal (11) causing the deflectors (1,2) to rotate in the opposite direction until they reach the active position.

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