WO2018192622A2

WO2018192622A2 - Method for relaxing a power train of a motor vehicle

Info

Publication number: WO2018192622A2
Application number: PCT/DE2018/100349
Authority: WO
Inventors: Marian Preisner
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2017-04-18
Filing date: 2018-04-13
Publication date: 2018-10-25
Also published as: CN110462262B; CN110462262A; DE102017108208A1; WO2018192622A3; DE102017108208B4

Abstract

The invention relates to a method for relaxing a power train of a motor vehicle, which comprises a semi-automatic transmission system. One gear is manually engaged and a clutch which is arranged between an internal combustion engine and the transmission is automatically actuated. The actuation of a gear shift lever for manually disengaging the gear is detected and the clutch is opened according to the detected movement. In a method in which no resistance is sensed when the gear shift lever is actuated, the power train relaxes according to a position of the gear shift lever, prior to the clutch being completely disengaged.

Description

The invention relates to a method for relaxing a drive train of a motor vehicle, which comprises a partially automated transmission system, wherein a gear is manually engaged and arranged between the engine and transmission clutch is automatically actuated and the operation of a selector lever for manual laying the gear is detected, wherein in response to the detected movement, the clutch is opened.

A method for controlling a drive train of a motor vehicle is known from DE 10 201 1 105 990 A1, in which a transmission, for example an automated manual transmission, is provided for spreading the usable speed band of the internal combustion engine. Between the crankshaft of the internal combustion engine and the at least one transmission input shaft of the transmission, a friction clutch is provided, which is controlled by a control unit. At successive interrupt intervals, powertrain skew angles of the powertrain are detected causing tension in the driveline.

The use of semi-automated transmission systems in which the driver engages the gear itself but the clutch is automatically actuated initiates a gearshift by the driver by moving the selector lever in the "disengage gear." A sensor detects the movement of the selector lever and thus causes the clutch to open and reduce engine torque.This reduction is necessary to allow the driveline to be relaxed and the gear to be laid out.

It is known to relax the driveline with a fixed gradient, depending on the gear and accelerator pedal. As a result of the tensioning of the drive train, a resistance arises in the actuating path of the selector lever when the driver has overcome the free travel in the selector lever, which is why further disengagement of the gear is not possible.

The invention has for its object to provide a method for relaxing a drive train of a motor vehicle, in which the driver feels no resistance when laying out the aisle.

According to the invention the object is achieved in that the drive train is relaxed in response to a position of the selector lever before the gear is completely designed. By the rapid relaxation of the drive train, the gear can be designed comfortably and without noticeable resistance, since the relaxation of the drive train is already fully formed during the free travel of the selector lever.

Advantageously, the clutch is already fully open when a free travel of the selector lever is overcome. This supports the relaxation of the drive train.

In one embodiment, a clutch torque and / or an engine torque for Ent-voltage of the drive train are reduced. Since this takes place during the free travel of the selector lever, thus a very fast relaxation of the drive train is achieved.

In a linear approach, the clutch torque is reduced when laying the gear in response to a distance traveled by the selector lever. As a result, the relaxation time for the drive train can be realized particularly quickly.

In a development, the clutch torque is assigned to an engine torque. By this is meant that the engine torque is set equal to the clutch torque so that both clutch torque and engine torque are reduced at the same time and preferably reach zero, at which point the complete relaxation of the drive train can be concluded.

Thus, the engine torque is also completely reduced when the free travel of the selector lever is overcome, the clutch torque is assigned to the engine torque only when the clutch torque is smaller than a driver's desired torque. The driver command torque, which is preferably set by the accelerator pedal by the driver, then corresponds to the engine torque that the engine would deliver if no external torque intervention were active. In one variant, the drive train is relaxed as a function of a speed of the selector lever when laying the gear. This ensures that the driver himself determines the comfort in a deployment process.

In a particularly simple embodiment, rapid deceleration of the drive train takes place during rapid movement of the selector lever. Alternatively, with a slow movement of the selector lever, a slower relaxation of the drive train takes place, although an increased comfort for the driver is set. In one embodiment, movement of the selector lever is detected from the beginning of the actuation. This ensures that the resistance-free free travel to be traversed by the selector lever is used completely to realize a relaxation of the drive train in this period.

The invention allows numerous embodiments. One of them will be explained in more detail with reference to the figures shown in the drawing. Show it:

Fig. 1: a schematic diagram of a partially automated transmission system with a

Selector lever with H-circuit diagram, Fig. 2: an embodiment of the method according to the invention.

In Fig. 1 is a schematic diagram of a partially automated transmission system 1 of a motor vehicle with a selector lever 2 for a gearshift with a H-circuit diagram 3 is shown. , For the sake of simplicity, the reverse gear has been omitted. Between a combustion engine 4 and a transmission 5, a clutch 6 is arranged. A control unit 7 is connected to the engine 4 and the clutch 6. In the semi-automatic transmission system 1, the gear is manually engaged or disengaged by operation of the selector lever 2 and the clutch 6 is automatically actuated by the control unit 7. The selector lever 2 is in the 4th gear of the H-circuit diagram 3 in the engaged state E. In the engaged state E, the selector lever 2 assumes the rest position s ₀ . To start a gear change, the selector lever 2 is moved from this rest position s _o in the direction of the neutral lane 8 in order to design the fourth gear. In this case, the selector lever 2 moves in the direction of the neutral lane 8 via the state "Will be designed" WA to the state "Gear is deployed" GA by the path s. This movement is detected by a sensor 9 and passed on to the control unit 7 of the vehicle. As soon as the sensor 9 detects the movement of the selector lever 2, the clutch 6 is opened by the control unit 7.

During the movement of the selector lever 2 from the rest position s _o , the selector lever 2 initially overcomes a free travel s _ma x, in which the selector lever 2 can be moved without resistance. If the selector lever 2 has traveled the free travel s _ma x, the beta tion of the selector lever 2 against a resistance, so that the gear can not be interpreted. To prevent this, proceed as follows:

So that the clutch 6 is fully open. if the free travel s _ma x is overcome, the following applies:

Trqcl = Trqcl, max [1- (s-So) / s max] (1) with

Trqcl current clutch torque,

Trqcl, max the clutch torque at the beginning of the selector lever movement,

So rest position of the selector lever 1 at the beginning of the selector lever movement, s the current position of the selector lever,

Smax the free travel of the selector lever, measured from the rest position So off.

To allow now during the free travel of the selector lever 2, a relaxation of the drive train of the motor vehicle, a clutch torque Trqcl the clutch 6 and an engine torque Trqeng of the engine 4 are completely reduced. So that the engine torque Trqeng is also completely reduced when the Leerweg s _ma xdes selector lever 8 is overcome, the clutch torque Trqcl the engine torque Trqeng assigned, provided that the clutch torque Trqcl is smaller than the driver request torque TrqDrvReq. Trqeng = Trqcl, if Trqcl <TrqDrvReq, (2) where

Trqeng current engine torque

TrqDrvReq driver request torque

The driver's desired torque corresponds to the engine torque that the engine 4 would deliver if no external torque intervention were active and is accordingly dependent on the position of the accelerator pedal of the vehicle. FIG. 2 shows an exemplary embodiment of the method according to the invention, the clutch torque Trqcl and the engine torque Trqeng being determined as a function of the movement. tion of the selector lever 2 are shown. In Fig. 2a, the selector lever path s is shown over time t, while in Fig. 2b the torque T is shown over time t. In this case, different courses of the clutch torque Trqcl and the engine torque Trqeng are shown. First of all, it is assumed that the clutch torque Trqcl always lies above the engine torque Trqeng (FIG. 2 b), so that the engine torque Trqeng can be transmitted to the wheels of the motor vehicle without slip. In an unwanted contact of the selector lever 2, which is represented by the elevation E in Fig. 2a, there is a lowering of the clutch torque to the value TrqcIA, which, however, has no effect on the output torque and on the clutch slip, since it is greater than the engine torque Trqeng is. Generally, this means that any movement of the selector lever 2 in the limits between the rest position So and a threshold value s _t0 i has no effect on the output torque and on the clutch slip (FIG. 2 b). Since the driver perceives only a reduction of the engine torque Trqeng and not the clutch torque Trqcl in an adhesive clutch, this volatile movement of the selector lever 2 remains up to a certain limit without effect on the drive train.

In Fig. 2a, the curve A shows a normal movement sequence in the operation of the selector lever 2 by the driver. After overcoming the idle travel s _ma x, both the engine torque Trqeng and the clutch torque Trqcl are reduced to 0 after the expiration of the time t2.

If the driver, as shown in Fig. 2a curve B, the selector lever 2 very quickly, allowing a sporty switching, the clutch torque Trqcl and the engine torque Trqeng are already reduced to 0 after the expiration of the period t1. In comparison, a comfortable switching is represented by the curve C in Fig. 2a, in which the selector lever 2 is moved quite slowly. In this case, the longest time duration t3 is required for passing through the idle travel s _ma x, so that the clutch torque Trqcl and the engine torque Trqeng move relatively slowly to 0 in comparison to the other shifting processes. Whenever the clutch torque Trqcl and the engine torque Trqeng have reached the value 0, the drive train is completely relaxed.

On account of the embodiments explained in connection with FIG. 2, the advantage consists in that, in the case of a regular disengaging of the gear, the drive train is decompressed as a function of the speed of the selector lever 2. This relaxes the drivetrain and opens the clutch in a natural and driver-specific manner. If the driver switches quickly, the drivetrain will also move quickly and under certain circumstances opened with a certain comfort restriction. The slower the selector lever movement, the more comfortable is the relaxation of the drive train, which can be read at the times t2 and t3.

LIST OF REFERENCE NUMBERS

transmission system

selector lever

H shift pattern

internal combustion engine

transmission

clutch

control unit

Neutral Lane

sensor

Claims

claims

1. A method for relaxing a drive train of a motor vehicle, which comprises a partially automated transmission system (1), wherein a gear is engaged manually and between a combustion engine (4) and transmission (5) arranged clutch (6) is automatically actuated and the operation of a selector lever (2) is detected for manual interpretation of the gear, wherein in response to the detected movement, the clutch (6) is opened, characterized in that the drive train in response to a position of the selector lever (2) is relaxed before the gear is completely designed ,

2. The method according to claim 1, characterized in that the coupling (6) is completely opened during overcoming an idle travel of the selector lever (2).

3. The method according to claim 1 or 2, characterized in that a clutch torque (Trqcl) and / or an engine torque (Trqeng) are reduced to relax the drive train.

4. The method according to claim 1, 2 or 3, characterized in that the clutch torque (Trqcl) when laying the gear in response to a by the selector lever (2) traveled path (s) is reduced.

5. The method according to at least one of the preceding claims, characterized in that the clutch torque (Trqcl) an engine torque (Trqeng) is assigned.

6. The method according to at least one of the preceding claims, characterized in that the clutch torque (Trqcl) the engine torque (Trqeng) is assigned when the clutch torque (Trqcl) is smaller than a driver's desired torque.

7. The method according to at least one of the preceding claims, characterized in that the drive train is relaxed as a function of a speed of the selector lever (2) when laying the gear.

8. The method according to claim 7, characterized in that at a rapid movement of the selector lever (2) there is a rapid relaxation of the drive train.

9. The method according to claim 7, characterized in that at a slow movement of the selector lever (2) takes place a slower relaxation of the drive train.

10. The method according to at least one of the preceding claims, characterized in that a movement of the selector lever (2) from the beginning of the operation is detected.