DE10030837A1 - Automatic clutch actuator for motor vehicle has drive transmitted by clutch briefly adjusted as engine and gearbox speeds are synchronised - Google Patents

Abstract

The motor vehicle uses a control to regulate the transmitted torque to a pre-set value (Meco) during set off of the vehicle when the accelerator pedal is actuated. The drive transmitted by the clutch (3) is at least briefly increased and lowered until it reaches equality between the engine (1) speed and gearbox speed to obtain tangential equalisation between the engine and gearbox.

Description

The invention relates to a motor vehicle with a device for automated Actuation of a clutch in the drive train of a motor vehicle.

DE 44 09 122 describes a device for regulating Motor vehicle clutch has become known, in which during a starting process the actuation is speed controlled in two phases. In a first phase the input speed leads to a target speed and in a second phase is a differential speed signal from the difference between a Input speed signal and an output speed signal one the specified target course up to the value zero.

An automated clutch control is known from DE 197 11 618 become, in which at a starting gear and not sufficient Acceleration through a targeted clutch opening an increased engine torque is set for the starting process.

The object of the invention is to provide a motor vehicle with a device for automated actuation of a clutch and a method of control too create, which a high comfort and a high during a start Acceleration is guaranteed and at the same time the frictional energy in the area the clutch is reduced.

According to the invention this is achieved in that in a motor vehicle with a device for the automated actuation of a clutch in the drive train of the vehicle, with a drive motor and a transmission, with a control unit and an actuator controlled by the control unit for actuating the clutch, with the accelerator pedal actuated during a start-up process, the torque M _k that can be transmitted by the clutch is increased and is essentially controlled to a predeterminable value M _should , the torque that can be transmitted by the clutch is increased, at least briefly, at least for a period shortly before the rotational speed equality between engine speed and transmission speed is reached and is lowered again to achieve a tangential adjustment between engine speed and gearbox speed. As a result, it is sufficient that after the setpoint of the control M has _{been reached} , an almost constant engine speed is set as the gearbox speed increases, and by increasing and then reducing the torque that can be transmitted by the clutch, the engine speed is reduced briefly before it increases again. As a result, the energy input in the area of the clutch is reduced and the acceleration of the vehicle is increased. By a closing lowering of the torque that can be transmitted from the clutch, a tangential approximation of the engine speed to the transmission speed is achieved, so that no torsional vibrations in the drive train are excited when the speed is the same. This improves the engagement process with regard to vehicle acceleration, energy balance and comfort.

Reducing the clutch torque shortly before reaching the Speed equality can occur with a speed difference between engine and Gearbox speed in the range of 50% to 10%, so that the short-term little opening of the clutch a faster and more comfortable Speed adjustment with a tangential adjustment of the speed curves causes.

It is particularly advantageous if the torque that can be transmitted by the clutch is increased from the first predeterminable value M ₁ to an increased value M ₂ at least briefly and then reduced again to M ₁ . The duration of the increase and the extent of the increase can, for example, be selected depending on the accelerator pedal actuation.

In another exemplary embodiment, it is expedient if the torque which can be transmitted by the clutch is increased from the first predeterminable value M ₁ to an increased value M ₂ and is then reduced again until the engine speed and gear speed are the same.

It is particularly advantageous if the torque that can be transmitted by the clutch is increased from M ₁ to M _{2 as a} function of the degree α of the accelerator pedal actuation. This results in an advantageous adaptation of the acceleration and the slip reduction to the accelerator pedal actuation set by the driver, which is particularly comfort-enhancing.

In another exemplary embodiment of the invention, it is expedient if the torque that can be transmitted by the clutch is increased from M ₁ to M _{2 as a} function of the speed and / or the acceleration of the vehicle.

Furthermore, it is expedient if that which can be transmitted by the clutch Torque according to the speed equality between engine speed and Gear speed is increased.

Embodiments of the invention are explained in more detail with reference to the figures, shows:

Fig. 1 is a schematic representation of a motor vehicle,

FIG. 2a is a diagram,

Fig. 2b is a diagram,

Fig. 3 is a timing diagram of vehicle data.

Fig. 1 shows a motor vehicle 1 with a drive motor 2 , with a clutch 3 and a transmission 4 in the drive train, the transmission being followed by a drive shaft 5 , which drives two drive shafts 7 a and 7 b by means of a differential 6 , which in turn drives the drive driven wheels 8 a and 8 b. The clutch 3 is shown as a dry friction clutch with a pressure plate 10 , clutch plate 11 , release bearing 12 and release fork 13 , which is mounted on a flywheel 9 , the clutch using a release fork 13 by means of an actuator 15 with a master cylinder 16 of a pressure medium line, such as hydraulic line 17 , and a slave cylinder 18 can be acted upon or operated. The actuator is provided with a sniffer bore 21 , which is connected to a reservoir 22 for the pressure medium. The actuator is shown as a pressure medium actuated actuator which has an electric motor 19 which actuates the master cylinder piston 20 via a gear so that the torque transmission system can be engaged and disengaged via the pressure medium line 17 and the slave cylinder 18 .

The actuation of the clutch can in a further embodiment Invention also by means of a purely hydraulic actuator with pump, Pressure accumulator and valves and slave cylinders take place, such as this has become known from DE 44 26 260.  

The clutch can also be actuated in a further exemplary embodiment the invention by means of a mechanical-electromotive actuator an electric motor as a drive and possibly a downstream one Gearbox.

Furthermore, the actuator 15 comprises a control unit 15 a with control electronics for controlling the actuation of the clutch by means of the actuator, wherein the power electronics and / or the control electronics can be arranged within the actuator housing 15 b. The arrangement of the electronics and the actuator can also be implemented within separate housings.

The vehicle 1 has various sensors for control purposes, the sensor signals of which are used by the control unit to generate the control signal. For example, the transmission 4 has a gear shift lever 30 with a gear recognition sensor 31 and / or a shift intention sensor 32 , which / which detects an actuation of the gear shift lever and / or the position of a transmission position.

Furthermore, the vehicle is equipped with at least one speed sensor 33 , which detects the speed of the transmission, such as the transmission output shaft. Instead, there may also be a sensor that detects the transmission input speed. Furthermore, a throttle valve sensor 34 is arranged, which detects the throttle valve position. There is also a speed sensor 35 which detects the engine speed. An accelerator pedal sensor 52 can also be arranged, which detects the degree of actuation of the accelerator pedal 51 , such as the accelerator pedal. Instead of the accelerator pedal sensor value, the signal from the throttle valve sensor 34 can also be used in order to obtain a measure of the accelerator pedal actuation.

The passage detection sensor 31 directly or indirectly detects the position of transmission-internal switching elements or the engaged gear in the gearbox, so that is registered by means of the signal of at least the engaged gear from the control unit 15 a. Furthermore, in the case of an analog sensor, the movement of the transmission-internal shifting elements can be detected, so that an early detection of the next gear engaged can be carried out. There is a data bus connection 60 , such as a CAN bus, between the individual control devices of the motor vehicle, such as the control unit 15 a of the automated clutch, and the engine control 50 , the control devices sending and / or receiving signals of the vehicle or of states or sensor data via this data bus . For example, the engine control can determine the engine speed and make it available to the other control units via the data bus, such as send, so that these other control units do not have to determine this size again.

When starting, the torque M _{K that can} be transmitted by the clutch is controlled as a function of the accelerator pedal position, such as the accelerator pedal, and / or the rate of change of the accelerator pedal position over time. Due to the increased engine speed when the accelerator pedal is actuated and the clutch torque M _K controlled by the control unit 15 a, which can be transmitted from the clutch, at least as much torque is transmitted to the drive wheels that the vehicle starts off.

The torque M _K that can be transmitted by the clutch is controlled according to the following formula:

M _K = M _{K_general} .V,

where:
M _K is the torque that can be transmitted by the clutch and that is controlled to a setpoint value M _target that is _dependent on the vehicle condition, M _{K_generally} is a general torque that can be transmitted by the clutch that, for example, depends on the engine speed, engine torque and / or by means of a map or a characteristic curve the accelerator pedal actuation is determined, and V is a factor which takes over the fine control for reducing the slip duration and the amount of slip and thus contributes to reducing the energy input in the area of the clutch.

FIGS. 2a and 2b show the dependence of the factor V as a function of the quotient n _Get / n between the _motor transmission speed n _Get and the engine speed n _engine. Fig. 2a shows an embodiment, in which shortly before equality of rotational speed at n _Get / n = _motor 1 at a predetermined value n _Get / n _engine = x, an increase in the factor V is controlled. After reaching the maximum value ΔV, the value of V drops back to the original value.

FIG. 2b shows an embodiment in which shortly before the rotational speed equality at n _Get / n = _motor 1 at a predetermined value n _Get / n _engine = x, an increase in the factor V is controlled. After reaching the maximum value IN, the value of V drops until the speed equality with n _Get / n _Motor = 1.

The value for increasing ΔV can be controlled as a function of the accelerator pedal actuation or the time change of the accelerator pedal actuation, so that the following applies: ΔV = f (α, dα / dt, ...). Different values ΔV ₁ and ΔV ₂ can thus be achieved with different values of the accelerator pedal actuation. The value x of the beginning of the increase can, for example, also be selected depending on the driving speed and / or depending on the accelerator pedal.

FIG. 3 is a timing chart of various vehicle sizes, as a function of time t. The curves are designated as follows: the accelerator pedal actuation or the throttle valve position 101 ; engine torque 102 ; the torque 103 that can be transmitted by the clutch; transmission speed 104 and engine speed 105 .

Before time ( 110 ) the accelerator pedal is not actuated, the clutch is disengaged. The engine speed is essentially at idle speed, the engine torque is at the drag torque value of approx. -50 Nm and the transmission speed is zero. At time ( 110 ) the accelerator pedal is actuated and the engine torque rises to a predeterminable value which corresponds to the accelerator pedal actuation. At the same time, the engine speed increases. The clutch is also engaged automatically so that the torque 103 that can be transmitted by the clutch increases and adjusts to the value M ₁ .

At time ( 111 ), engine torque 102 and engine speed 105 are almost constant, and transmission speed 104 increases.

At time ( 112 ) at constant engine speed 105 , at constant engine torque 102 and at constant torque 103 that can be transmitted by the clutch, the factor V for controlling the torque M _K transmitted by the clutch is increased according to FIGS. 2a or 2b.

This increases the torque 103 that can be transmitted by the clutch and the engine speed 105 drops slightly. After the maximum of M _K ( 103 ) has been exceeded, M _K drops again until the speed equality of engine and transmission speed is reached at time ( 113 ).

By lowering the torque that can be transmitted by the clutch the engine speed nestles tangentially to the increasing gear speed.

The claims submitted with the application are drafted strikes without prejudice for obtaining further patent protection. The The applicant reserves the right to add more, so far only in the description and / or To claim drawings disclosed combination of features.

Relationships used in subclaims point to further training the subject of the main claim by the features of the respective towards subclaim; they are not considered a waiver of achieving one independent, objective protection for the combinations of features of to understand related subclaims.

Since the subjects of the subclaims with regard to the prior art reserves the right to make its own independent inventions on the priority date Applicant before becoming the subject of independent claims or part to make statements of compliance. You can also continue to invent independently containing one of the subjects of the preceding subclaims have independent design.

The exemplary embodiments are not to be understood as a limitation of the invention hen. Rather, there are numerous variations within the scope of the present disclosure  Rations and modifications possible, especially such variants, elements and combinations and / or materials, for example by combination or modification of individual in connection with that in the general Be writing and embodiments and the claims described and in the features or elements contained in the drawings or procedural step ten can be removed by the person skilled in the art with a view to solving the problem and through combinable features to a new item or new ones Lead process steps or process step sequences, also insofar as they Test and work procedures concern.

Claims (6)

1. Motor vehicle with a device for the automated actuation of a clutch in the drive train of the vehicle, with a drive motor and egg nem, with a control unit and an actuator controlled by the control unit ge for actuating the clutch, wherein with actuated Fahrpe dal during a start-up process of the clutch transmissible torque M _{k is} increased and is essentially controlled to a predeterminable value M _intended , characterized in that the torque which can be transmitted by the clutch is increased at least briefly before reaching the speed equality between engine speed and transmission speed and is reduced again and again by to achieve a tangential alignment between engine speed and gearbox speed. 2. Motor vehicle according to claim 1, characterized in that the torque which can be transmitted from the clutch is increased from the first predeterminable value M ₁ to an increased value M ₂ and is then reduced again to M ₁ . 3. Motor vehicle according to claim 1, characterized in that the torque that can be transmitted from the clutch is increased from the first predeterminable value M ₁ to an increased value M ₂ and is then reduced again until the speed equals between the engine and transmission speeds. 4. Motor vehicle according to claim 2 or 3, characterized in that the increase in the transmissible torque of the clutch from M ₁ to M _{2 is} dependent on the degree of accelerator pedal actuation. 5. Motor vehicle according to claim 2 or 3, characterized in that the increase in the torque transmitted by the clutch from M ₁ to M _{2 is} dependent on the speed and / or acceleration of the driving tool. 6. Motor vehicle according to one of the preceding claims, characterized records that the torque transmitted by the clutch after the Speed equality between engine speed and transmission speed is increased.