FR2795791A1 - MOTOR VEHICLE HAVING AUTOMATED CLUTCH ACTUATING DEVICE - Google Patents

Abstract

The invention relates to a motor vehicle with a device for automated clutch (3) actuation in the drive train of said motor vehicle, enabling the vehicle to start in a comfortable manner. The motor vehicle is fitted with a driving engine (2) and a gearbox (4), comprising a control unit (50) and an actuator which is controlled by the control unit and used to actuate the clutch. When the drive pedal (51) is actuated in a start procedure, the torque (Mk) which is transmitted by the clutch (3) is increased and substantially controlled according to a predefinable value (Msoll), and the torque transmitted by the clutch before the gearbox speed and engine speed reach the same speed is at least increased over a short time period and continually decreased in order to achieve a tangential balance between engine speed and gearbox speed.

Description

The invention relates to a motor vehicle having a device for the automated actuation of a clutch or a similar coupling device in the driveline of a motor vehicle.

By the document <B> DE </ B> 44 <B> 09 </ B> 122, there is known a device for regulating a clutch of a motor vehicle, by which, during a departure or rolling of the vehicle, the The actuation of the clutch is regulated, as regards the rotational speeds, in two phases. In a first phase, the input rotational speed is brought <B> to </ B> a set rotational speed, and, in a second phase, a differential rotational speed signal, derived from the difference between a input rotational speed signal and an output rotational speed signal, is slaved to a setpoint curve prefixed to the null value.

By the document <B> DE 197 Il 618, </ B> there is known an automated control of clutch, with which, during a departure, while a starting speed is engaged, but the acceleration is insufficient, an increased engine torque is placed at the disposal of the vehicle by a targeted disengagement of the clutch.

The object of the invention is to create a motor vehicle, having a device for the automated actuation of a clutch or a similar coupling device, and a driving method, ensuring a high level of comfort and reliability. strong acceleration during a departure and at the same time reducing the friction energy at the clutch.

Starting from a motor vehicle having a device for automatically actuating a clutch or a similar coupling device in the vehicle drivetrain, comprising a driving motor and a gearbox, or general, a gear change, a control unit and an actuator controlled by the control unit and serving <B> to </ B> the actuation of the clutch, in which, during a departure or implementation when the accelerator pedal is actuated, the torque Me transmitted by the clutch is increased and set essentially <B> to </ B> a Meco setpoint that can be prefixed, we obtain this result, in accordance with <B> to </ B> the invention, in that the torque transmittable by the clutch is at least briefly increased and lowered again <B> - </ B> essentially in at least a short time < B> - </ B> before the equality of speed is reached is between the rotational speed of the engine and a speed of rotation of the gearbox in order to obtain a tangential (progressive) equalization between the engine speed and the gearbox speed. This results in the fact that after the Meco control setpoint has been reached, an almost constant motor speed and a growing gear speed are established and that, by the increase and the consequent reduction of the transmittable torque by the clutch, the engine speed is briefly reduced before it goes back up again. In this way, the energy input at the clutch is reduced and the acceleration of the vehicle is increased. By a consequent lowering of the torque transmissible by the clutch, a tangential approximation of the motor speed <B> to </ B> is obtained at the speed of the box, so that when it <B> y </ B> between these two rotational speeds, torsional oscillations are not excited in the driveline. The clutch operation is thus improved with respect to vehicle acceleration, energy balance and comfort.

The torque reduction transmissible by the clutch, shortly before the equality of the rotational speeds of the engine and of the gearbox, can be achieved in the range of difference between these two speeds ranging from <B> 50% to 10%, so that the low clutch short time clutch causes a faster and more comfortable adjustment by tangential or progressive equalization of the variation curves of these two speeds of rotation.

<B> It </ B> is particularly advantageous that the torque transmissible by the clutch is at least briefly increased by a first value Ml, which can be prefixed, <B> to </ B> an increased value M2 and that it is then lowered again <B> to </ B> Ml. The duration and magnitude of the increase may be chosen to depend, for example, on the actuation of the accelerator pedal.

According to another exemplary embodiment, it is expedient for the torque transmissible by the clutch to be increased by a first value M1, which can be prefixed, <B> to </ B> by an increased value M2 and then decreased again until the rotation speeds of the engine and the gearbox are equal. It is particularly advantageous that the increase in torque transmissible by the clutch, from Mi <B> to </ B> M2, is effected as a function of the amplitude # of the actuation of the accelerator pedal. This provides an advantageous adaptation of the acceleration and reduction of the slip <B> to </ B> the amplitude of actuation of the accelerator by the driver, which provides a significant improvement in comfort.

According to another exemplary embodiment of the invention, it is expedient that the increase in the torque transmissible by the clutch, from Ml <B> to </ B> M2, is effected as a function of the speed and / or acceleration of the vehicle.

It is also appropriate that the torque transmissible by the clutch is increased after achieving equality of rotation speeds between the engine and the box.

Other characteristics and advantages of the invention will emerge more clearly from the following description of nonlimiting exemplary embodiments, as well as the appended drawings, in which: <B>: </ B> <B> - </ B > Figure <B> 1 </ B> is a schematic representation of a motor vehicle <B> - </ B> Figure 2a is a diagram illustrating the increase and decrease according to the invention of the torque transmissible by clutch <B> - </ B> Figure <B> 2b </ B> is a similar diagram <B>; </ B> and <B> - </ B> Figure <B> 3 </ B> is a time-based representation of vehicle running parameters.

Figure <B> 1 </ B> represents a motor vehicle <B> 1 </ B> equipped with a drive motor 2 and including a clutch <B> 3 </ B> and a gearbox 4 in the driveline, the box being followed by a drive shaft <B> 5 </ B> driving, via a differential <B> 6, </ B> two shafts of wheels 7a and <B> 7b, <B> to </ B> turn the driving wheels 8a and <B> 8b. </ B> The clutch <B> 3 </ B> is represented as a clutch <B> to </ B> friction <B> to </ B> dry, having a pressure plate <B> 10, </ B> a clutch plate <B> 11, </ B> a disengagement stop 12 and release fork <B> 13. </ B> The clutch is mounted on a flywheel <B> 9 </ B> and can be loaded or actuated via the release fork <B> 13, </ B> by an actuator <B> 15 </ B> having a cylinder emitter <B> 16, </ B> a pressure medium line, a hydraulic line <B> 17 </ B> for example, and a cylinder Receiver <B> 18. </ B> The actuator is provided with an inlet / exhaust port 21 communicating with a reservoir 22 for the pressure medium. The actuator is shown as a device powered by a pressure medium and having an electric motor <B> 19 </ B> acting via a speed reducer on the piston 20 of the emitter cylinder, so that the torque transmission system can be engaged and disengaged through the pressure fluid line <B> 17 </ B> and the receiving cylinder <B> 18. </ B>

According to another embodiment of the invention, the actuation of the clutch is also possible by a purely hydraulic type actuator, comprising a pump, a pressure accumulator, valves and a receiver cylinder, as known from example by the document <B> DE </ B> 44 <B> 26 260. </ B>

 The actuation of the clutch can be performed again, according to another embodiment of the invention, by an actuator of the mechanical type <B> to </ B> electric motor, having an electric motor for the training and possibly followed by a speed reducer.

The illustrated <B> 15 </ B> actuator further comprises a control apparatus 15a with a control electronics for controlling actuation of the clutch by the actuator. The power electronics and / or control electronics can or can be housed in the housing <B> 15b </ B> of the actuator, but it is also possible to house the electronics and the actuator itself in separate housings.

The vehicle <B> 1 </ B> has, for control, various sensors whose signals are used by the control unit 15a for the purpose of generating the pilot signal for actuating the clutch. For example, the gearbox 4 has a shift lever <B> 30 </ B> to which is or are coordinated (s) a sensor <B> 31 </ B> to detect the gear engaged in the gearbox. box and / or sensor <B> 32 </ B> to detect a shift intention. These two sensors make it possible to detect the actuation of the shift lever and / or the speed or gear ratio of the gearbox.

The vehicle is equipped in addition to at least one speed sensor <B> 33 </ B> which detects a rotation speed of the gearbox, for example the output speed of the gearbox by means of a sensor < B> 33 </ B> installed between the drive shaft <B> 5 </ B> and the differential <B> 6. In the place of such a sensor, it is also possible to provide a sensor for detecting the rotation speed <B> at the entrance to the box 4. A butterfly sensor 34 is also provided. to detect the position of the throttle valve. The vehicle is also equipped with a speed sensor <B> 35 </ B> to detect the rotational speed of the engine 2. The vehicle can be equipped in addition to an accelerator sensor <B> 52 </ B > which detects the amplitude of activation of the accelerator pedal <B> 51. At the location of the signal provided by the latter sensor, it is also possible to use the throttle sensor signal 34 to obtain an indication of the amplitude of the accelerator pedal operation.

The sensor <B> 31 </ B> detects directly or indirectly the position of internal elements of the gearbox or the speed (gear) engaged in the gearbox, so that its signal allows at least <B> to < The steering unit 15a to record the engaged speed. If it is an analog sensor, it allows in addition to detect the movement of the internal elements of the box, so that the next gear engaged can be detected early. Between the different control devices of the motor vehicle, such as the control unit 15a of the automated clutch and the motor control <B> 50, <B> 60 </ B> exists by a data bus, a CAN bus for example, <B> to </ B> through which the control and / or control devices transmit and / or receive signals from the vehicle or relative <B> to </ B> states or data provided by the sensors. For example, the motor control can determine the rotational speed of the motor and put it <B> at </ B> disposal, for example by its transmission <B> to </ B> through the data bus, to other devices of steering / control, so that they are not obliged to determine said size again.

When starting or starting the vehicle, the torque Me transmissible by the clutch <B> 3 </ B> is adjusted or controlled according to the position of the accelerator pedal <B> 51 </ B > or a similar organ and / or the rate of change of its position. Under the effect of the increase of the engine speed, as a result of the actuation of the accelerator, and the torque Me set by the control unit 15a and transmittable by the clutch, the drive wheels 8a, <B > 8b </ B> are at least large enough for the vehicle to start <B> rolling. The torque Me transmitted by the clutch, is set according to the following formula Me <B≥ </ B> Megén <B> * </ B> V, <B> WHERE </ B> Me is the torque transmissible by the clutch, which is set <B> to </ B> a Meco setpoint according to a vehicle parameter, Megén is a general torque transmittable by the clutch, which is fixed by a characteristic diagram or a characteristic curve, for example, depending on the speed of rotation of the engine, the engine torque and / or the operation of the accelerator pedal, and V is a factor corresponding to the fine adjustment to reduce the duration of the slip and its importance ( of its speed) and therefore contributes <B> to </ B> reducing the energy input at the clutch.

Figures 2a and <B> 2b </ B> show the dependence of factor V as a function of the quotient nbo / rimot between box speed nbc) and engine speed nmc) t. FIG. 2a shows an exemplary embodiment in which an increase in the factor V is applied <B> to </ B> a nbo / rimot value <B≥ </ B> x that can be prefixed, shortly before the equality of rotational speeds are obtained <B> at </ B> nbo / nmc) t <B≥ 1. </ B> After the maximum value AV has been reached, the value of V goes down again <B> to < / B> the original value.

Figure <B> 2b </ B> shows an example embodiment in which an increase of the factor V is also applied, <B> to </ B> a nboffimot value <B≥ </ B> x can be prefixed, little before equality of rotation speeds is obtained <B> at </ B> nboffimot <B≥ 1. </ B> After the maximum value AV has been reached, the value of V decreases until the equality of rotation speeds is obtained <B> at </ B> nbo / nmot <B≥ 1. </ B>

The AV increase value can be adjusted according to the action of the accelerator pedal or the variation in time of this actuation, so that <B>: </ B> AV <B≥ < / B> fx, du / dt, <B> ...). </ B> Different values AV1 and AV2 can thus be obtained for different values of the actuation of the accelerator pedal. The value x of the beginning of the increase can also be chosen, for example, as a function of the running speed of the vehicle and / or according to the actuation of the accelerator. Figure <B> 3 </ B> is a time-based representation of different vehicle parameters. The actuation of the accelerator pedal or the position of the throttle valve is represented by the curve <B> 101, </ B> the engine torque by the curve 102, the torque transmittable by the clutch by the curve <B > 103, </ B> the box speed by the curve 104 and the motor speed by the curve <B> 105. </ B>

Before the instant <B> (110), </ B> the throttle is not actuated and the clutch is disengaged. The engine speed is essentially <B> at </ B> the idle speed, the engine torque corresponds to the idle torque of approximately <B> - 50 </ B> Nm and the speed of the gearbox is zero. <B> At <B> (110), </ B> the throttle is activated and the engine torque rises to a prefixable value. , corresponding <B> to </ B> the actuation of the accelerator. The motor speed rises simultaneously. Similarly, the clutch is automatically engaged (partially), so that the torque <B> 103 </ B> transmitted by the clutch increases and adjusts <B> to </ B> the value Ml.

<B> At <B> (111), </ B> the engine torque 102 and the engine speed <B> 105 </ B> are almost constant and the gearbox speed 104 .

<B> at </ B> the instant (112), the motor speed <B> 195 </ B> being constant, the motor torque 102 being constant and the torque <B> 103 </ B> transmittable by the Since the clutch is also constant, the factor V for controlling the torque Me trans missible by the clutch is increased according to Figure 2a or <B> 2b. </ B>

As a result, the torque <B> 103 </ B> transmitted by the clutch increases and the motor speed <B> 105 </ B> decreases slightly. After exceeding the maximum of Me <B> (103), Me goes down again, until, <B> at </ B> the instant <B> (113), </ B> the engine and gearbox rotation speeds are equal.

As a result of the reduction in torque transmissible by the clutch, the rotational speed of the motor is adjusted tangentially <B> to </ B> the increasing speed of rotation of the gearbox.

The claims filed together with this application are proposals for wording without prejudice to obtaining broader protection. The applicant reserves the right to claim further combinations of features heretofore disclosed only in the description and / or drawings. Attachments used in dependent claims, refer to the development of the subject matter of the main claim by the features of the dependent claim in question <B>; </ B> they are not <B> to </ B> to consider as a waiver to obtain standalone device protection for the feature combinations of the dependent dependent claims.

Since the subject-matter of the dependent claims may, in the light of the prior art on the priority date, constitute independent and independent inventions, the plaintiff reserves the right to be the subject of independent claims or divisional applications. . They may further contain autonomous inventions having a configuration independent of the objects of the preceding dependent claims.

The exemplary embodiments should not be understood as limiting the invention. On the contrary, many changes and modifications are possible in the context of the present disclosure; <B> these are in particular variants, elements and combinations and / or materials which, for example by combination or modification of individual features, elements or process steps, described in connection with the general description and embodiments as well as the claims and contained in the drawings, are usable by those skilled in the art for the solution of a problem and may lead, by characteristics that may be combined, to a new object, or new process steps or sequences, <b> y </ B> included insofar as they concern production, control and work processes.

Claims (1)

<U> CLAIMS </ U> <B> 1. </ B> Motor vehicle <B> (1) </ B> having a device for automated actuation of a clutch <B> (3) </ B or a similar coupling device in the kinematic chain of the vehicle, comprising a drive motor and a gearbox or, in general, a gearshift, a drive unit and an actuator driven by the control unit and serving <B> to </ B> the actuation of the clutch, wherein, during a departure or rolling of the vehicle, while the accelerator pedal is actuated, the torque Me transmissible by the clutch is increased and set essentially <B> to </ B> a Meco setpoint that can be prefixed, characterized in that the torque transmissible by the clutch is at least briefly increased and lowered again before achieve equal speed between the rotational speed of the motor and a rotational speed of the gearbox. speeds in order to obtain a tangential equalization between the motor speed and the gear speed. 2. Motor vehicle according to claim 1, characterized in that the torque transmissible by the clutch <B> (3) </ B> is increased by a first value M1, which can be prefixed, <B> to </ B> an increased M2 value and is then lowered from <B> to </ B> Mi. <B> 3. </ B> A motor vehicle according to claim 1, </ B> characterized in that the torque transmissible by the clutch <B> (3) </ B> is increased <B> to </ B> from a first value M1, which can be prefixed, <B> to </ B> an increased value M2 and is then lowered again until the speed is equalized between the engine speed and the gear speed. 4. Motor vehicle according to claim 2 or <B> 3, </ B> characterized in that the increase in torque transmissible by the clutch <B> (3), </ B> of Ml <B> to < / B> M2, is effected according to the amplitude of operation of the accelerator pedal <B> (51). </ B> <B> 5. </ B> The motor vehicle according to claim 2 or <B> 3, </ B> characterized in that the increase of the torque transmissible by the clutch <B> (3), </ B> from Ml <B> to </ B> M2 is effected by according to the speed and / or the acceleration of the vehicle. <B> 6. </ B> Motor vehicle according to one of the preceding claims, characterized in that the torque transmissible by the clutch <B> (3) </ B> is increased after achieving equal speed between the engine speed and the gearbox speed.