DE19841917A1 - Drive system for motor vehicles - Google Patents

Abstract

The system incorporates a regulator unit (13) for a an automatic clutch operator. The unit has a module (14) for control of a crawling movement of the vehicle. This is activated, when it recognizes that the vehicle has stopped, or almost stopped, the accelerator pedal is not operated and the first hear is engaged and the engine is started. When the module is activated, the regulator unit is operated to ready the transfer of a set momentum to the transmission (21). The momentum is within a set range of pref. 8 - 15Nm. The regulator unit has associated sensors (43,41) for load and road angle.

Description

The invention relates to a drive arrangement according to the preamble of the patent claim 1 and a method of operating the same.

From DE 32 43 461 A1, for example, it is a drive arrangement with a burner engine, the power of which can be adjusted by means of an associated throttle valve, and with an automatically operated friction clutch between the internal combustion engine machine and a downstream manual transmission is known. That before Manual transmission seen can be actuated automatically by means of assigned actuators. This drive arrangement has a control device, which at least signals from the driving speed, the actuation position of the accelerator pedal and a brake sensors indicating actuation. The turned on in the manual transmission Driving gear is put by the control device by actuation of the transmission assigned actuators, so that the information of the currently selected gear is present. The between internal combustion engine and The gearbox provided clutch is an actuator, designated by the second actuator net, assigned by which the clutch can be actuated automatically. For a crawl movement of the vehicle by positioning the shift lever on actuation Position "D" can be selected, the friction clutch will alternate by means of the actuator  rend out and indented so that the vehicle begins to crawl. This actuation mode of alternating engagement and disengagement of the friction clutch is included called semi-engaged state. This clutch actuation is only at unbe actuated or almost unactuated accelerator pedal and unactuated brake provided. With the actuation of the brake becomes the actuator for the automated actuation of the Coupling controlled to disengage the same.

A disadvantage of this drive arrangement and the method of the intermittent Establishing a flow of force via the friction clutch that initiates the movement ting actuator is heavily loaded. Furthermore, the alternating on and Disengagement of the clutch initiated torque fluctuations in the transmission, from which a gear rattle can result. That about the clutch and the nachge shifted manual transmission to the drive wheels transmitted drive torque is corre sponding According to the clutch control subject to fluctuations. These fluctuations of the drive torque can be experienced as uncomfortable by the driver.

DE 26 56 888 A1 describes a creep drive control system for an industrial vehicle known. This industrial vehicle has a hydraulic braking system with which a clutch is coupled. When the Hy exceeds a predetermined level Draulikdruck in the brake system, the clutch is disengaged. When releasing the brake The clutch becomes dependent on the Hy prevailing in the brake system Draulikdruck automatically engaged to start the vehicle, so that the vehicle performs a smooth creep. With this system, when still actuated Brake already transmitted a moment via the clutch, so that a roll back of the Vehicle on an inclined roadway just before the crawl movement begins can use.

The disadvantage of this creep drive system is that the brake is still applied Clutch is already engaged. The vehicle is on an inclined road and the vehicle is affected by the acting braking torque together with the over the Clutch transmitted torque is kept at rest, so the clutch is by the in the clutch generated friction power heavily loaded without the driver of gained knowledge of this operating state of the friction clutch. Because of the still  continuous brake application, he will assume that the vehicle is braking actuation is kept at rest.

From EP 375 162 B1 and DE 689 20 850 T2 is a control system for a Vehicle clutch known. In this control system it is provided that the driving tool movement in the speed range of a creep only by the Operation and release of the braking device is controlled, one in the drive train provided friction clutch is provided depending on in a Manual gear engaged and the operating position of the brake pedal moved. If the accelerator pedal is not pressed and the brake pedal is not pressed, the Clutch operated with slip, the torque transmitted via the clutch still depends on the selected gear.

The disadvantage of this control system is that even when the brake is still applied Torque is transmitted via the clutch, causing an excessive load on the Coupling, as already explained, goes hand in hand. In turn, a halt state a vehicle from the acting braking force and the superimposition of the Clutch transmitted driving force result, the clutch being held in this condition is heavily loaded.

From JP 61-150841 A with application number 59-278193 is a drive arrangement known, which has a friction clutch, with an associated scarf a crawl driving mode can be selected. For creeping, simultaneously with Lö sen the brake engaged the friction clutch, so that by the friction clutch transmitted moment a creeping of the vehicle results.

The disadvantage of this drive arrangement is that the friction clutch in turn brake is still engaged, which increases the load on the friction clutch, as already explained, goes hand in hand. Another disadvantage is that a too additional actuation button or actuation switch for activating this driving mode is provided, which is negative due to the variety of controls affects the clarity of the driver's cab. The curtain also stands being of a variety of controls for ease of use in the Sin ne that the driver must first familiarize himself with all controls, ent  against. If in particular the vehicle is operated by several vehicle drivers, then it can also happen that the predecessor presses the button or Has operated the switch and this actuation when restarting the drive stuff was no longer conscious, or another driver of the vehicle in Be drive takes and surprised by the vehicle reaction of an automatic start becomes. This can lead to dangerous driving situations.

From DE 44 26 260 A1 is a drive arrangement with a between a burner engine and a manual transmission arranged automated friction clutch lung known. With the engine running and the vehicle practically stationary, and not When the accelerator pedal is pressed, the clutch is used to transmit a small torque, from which a crawling of the vehicle results. It is also provided hen that the clutch when actuating the brake in the disengaging direction by means of the Stell member is operated.

The disadvantage of this drive arrangement is that, in turn, the simultaneous actuation of friction clutch and brake is approved, which increases the load on the Friction clutch is allowed. It is further provided that such a Mo ment is transmitted via the clutch, so that due to this moment An crawling of the vehicle results. If the vehicle is on a slope, it is the moment required to crawl, considerably. If the friction clutch with Slip operated, so is the drop in friction in the clutch and thus the Be load of the friction clutch from the torque to be transmitted via the clutch dependent. Is a much higher moment compared to that for crawling at level roadway is required, so the clutch when providing a Krie heavily burdened.

The object of the invention is a drive arrangement and a method for a crane Chen to provide the vehicle, through which a quiet creep without a raise allow the coupling to be loaded.

The object of the invention is achieved by the features given in claim 1 solved. By taking the measure that the module An is only released when the brake is completely released crawl is activated, with activated module to initiate a creep  of the vehicle, the actuating device assigned to the clutch for providing the Transfer of a fixed predetermined torque to the downstream transmission is controlled, a drive arrangement is provided in which a creeping of the Vehicle can only be provided under safe loads on the friction clutch. The torque that can be transmitted via the friction clutch to provide a crawl chen of the vehicle is limited by the predetermined moment, whereby the in the Clutch generated friction is limited. Preferably the moment is on one Maximum value limited at which a permanent slip operation without excessive bela Stung the friction clutch is given. This is preferably via the friction clutch permissible maximum torque in the value range from 8 to 15 Nm arranged. It has proven to be advantageous that in the control device Characteristic curves, a relation between actuator position and that of the friction clutch producing transmitted torque are stored, the characteristic curves or the values taken from the characteristic curves for the current state of wear of the rei exercise clutch are adjusted.

In a preferred embodiment, an electromotive is used as the adjusting device Actuator provided. Such electromotive actuators can be positioned exactly and inexpensive for drive assemblies that do not have a hydraulic system applicable.

It has proven to be advantageous to control a creep process next to control the motor to provide increased torque. It has In particular, it was found to be advantageous to initiate a creeping movement Motor to provide a torque transmitted via the clutch, plus of the friction torque dropping in the friction clutch plus an offset control to decelerate the crankshaft referred to as engine depression counteract. It has proven to be advantageous when creeping movement begins to zero this offset to prevent the engine from revving up Act.

Further advantageous measures are described in further claims.  

The invention is described below with the aid of a few exemplary embodiments. It shows:

Fig. 1 drive arrangement;

Fig. 2 flow chart showing an embodiment of a method for controlling a crawling of a motor vehicle.

Referring to Fig. 1, first a possible structure of a drive assembly 1, by the creep of a vehicle can be provided is described. The drive arrangement 1 shown has a drive motor in the form of an internal combustion engine 3 . The internal combustion engine 3 is provided with a power actuator 7 for actuating a throttle valve 5 , by the position of which the power output from the internal combustion engine 3 can be adjusted. The internal combustion engine 3 can be brought via a downstream friction coupling 9 with a manual transmission 21 in operative connection. The Rei clutch 9 is a controlled by a control device 13 actuator 11 before preferably electrically motorized actuator 12 for automated actuation of the friction clutch 9 . The control device is a throttle valve sensor 29 , a sensor 27 recording the clutch position, an engine speed sensor 31 and a sensor 33 recording the speed of the transmission input shaft, a sensor 35 indicating a selected gear, the wheel speed sensors 39 , a clutch temperature sensor 37 , a sensor 41 that measures the gradient of the road, a load sensor 43 that measures the load state of the vehicle, an accelerator pedal sensor 45 that indicates the actuation position of an accelerator pedal 15, and a brake pedal sensor 47 that indicates the actuation position of the brake pedal 17 . Depending on the signals sent to the Steuerein device 13 , in particular the power actuator 7 and the actuator 11 are actuated to actuate the friction clutch 9 . In the exemplary embodiment shown, the manual transmission can be actuated manually by means of a shift lever 19 . However, it can also be provided that the gears are engaged automatically by means of assigned actuators. Via a differential 23 connected downstream of the manual transmission 21 , associated drive wheels 25 are operatively connected to the manual transmission 21 .

The commissioning and in particular the control of a creep process are described in more detail with reference to FIG. 2. In a first step S1, a query is made as to whether the internal combustion engine 3 has been started up. If the internal combustion engine 3 is started, the process continues with step S2 in that the vehicle speed is queried. If the driving speed V detected by the control device 13 is less than or equal to a predetermined limit speed V gr., Which is almost zero, the process continues with step S3. If the driving speed, which is preferably sensed by means of the sensors 39, is greater than the predetermined limit speed, the control device detects that the vehicle is rolling or that the journey continues with step S11. Since normal driving should not be the subject of this invention, a description of the vehicle control in the event of the vehicle exceeding the limit speed will not be dealt with in more detail.

In step S3, the control device 13, preferably by means of the transmission sensor 35, queries the currently selected gear in the manual transmission. It can also be provided, in the case of a vehicle that has already rolled up, to determine the transmission input speed, which is sensed by means of the sensor 33 , and the driving speed in the manual transmission 21 to determine the gear ratio already engaged. If a starting gear in the form of the first or the reverse gear is engaged, the procedure continues with step S4. Otherwise, the control device 13 queries in step S12 whether a gear is engaged in the manual transmission 21 . If a higher gear than the first or the reverse gear is engaged, in particular a higher gear than the second gear, then when the accelerator pedal 15 is actuated, the control device 13 controls starting in a non-starting gear. If no gear is engaged in the manual transmission 21 , the process continues with step S2. Provided that a starting gear is engaged, a query is made in step S4 as to whether the accelerator pedal 15 is actuated. If an actuation of the accelerator pedal 15 is detected, the process continues with step S14, the control of a normal starting process, otherwise it is checked in step S5 whether the brake pedal is actuated. If the brake pedal is actuated, this check is repeated. It can also be provided that it is first queried whether the brake pedal is actuated and, if the brake pedal is not actuated, it is subsequently queried whether the accelerator pedal is actuated. If the control device 13 detects an unactuated accelerator pedal and an unactuated brake pedal, the step creep 14 activates the module 14 activated in the control device 13 . The actuator 11 is ereinrichtung through the CONT 13 to carry driven the predetermined torque, and the power actuator 7 is in said Rei bung clutch 9 sloping friction losses plus the data transmitted via the friction coupling 9 torque plus a predetermined offset controlled for providing a by the amount. When the crawl movement of the vehicle begins, the offset is brought to zero. It may also be envisaged that the power actuator 7 for providing a is controlled by the amount of the resulting friction power in the friction clutch 9 plus the bung on the Rei clutch transmitted torque. During the Schlupfbe operation of the friction clutch 9 , the clutch temperature is monitored by means of the sensor 37 , and if a predetermined temperature limit is exceeded, shown with step S7, the creeping process is terminated, as shown with step S15. When the crawling process and thus deactivating the crawling module are terminated, it can either be provided that the clutch be disengaged completely, which could then be continued with step S2 in the following, or the clutch is fully engaged, which leads to the engine stalling, if the driver of the vehicle Does not perceive the situation and fails to actuate the accelerator pedal, which then initiates a normal starting process. If the detected clutch temperature is below the temperature limit value, the process continues with step S8. In step S8 it is checked whether the vehicle speed is less than or equal to a maximum permissible limit speed predetermined for a creeping process. Upon detection of a speed exceeding the predetermined limit speed, the actuator 11 is actuated in step S16 to actuate the friction clutch in the disengaging direction, preferably by a predetermined increment. It can also be provided to control an automated actuation of the friction clutch 9 in the disengaging direction depending on the extent of the speed exceeding the maximum permissible limit speed during a crawling process. Steps S7 and S8 can also be carried out in reversed order or queried in parallel. The clutch temperature and the vehicle speed are checked during the entire crawling process with regard to the set limit values and, if necessary, the corresponding measures described above are initiated. The vehicle is controlled by the crawl module until an accelerator pedal actuation or a brake pedal actuation is recognized in step S9, with the crawl module being deactivated in step S10 when one of these actuations is recognized. Upon detection of an accelerator pedal actuation, the friction clutch 9 is fully engaged and a normal starting process S14 with accelerator pedal actuation is controlled by the control device 13 . With detection of an actuation of the brake pedal 17 by means of the associated sensor 47 , the friction clutch 9 is completely moved out, whereby no more drive torque is transmitted to the drive wheels 25 . In the following, it can be continued with step S5, and when the brake pedal is detected which is no longer actuated, a new crawling process can be initiated by activating the crawling module 14 .

Reference list

1

Drive arrangement

3rd

Internal combustion engine, drive motor

5

throttle

7

Power actuator

9

Friction clutch

11

Actuator

12th

electric motor actuator

13

Control device

14

module

15

Accelerator pedal

17th

Brake pedal

19th

Gear lever

21

Manual transmission

23

differential

25th

Drive wheels

27

Sensor for detecting the clutch position

29

Throttle position sensor

31

Engine speed sensor

33

Transmission input shaft speed sensor

35

Transmission sensor

37

Temperature sensor

39

Wheel speed sensors, vehicle speed sensor

41

Incline sensor

43

Load sensor

45

Accelerator pedal sensor

47

Brake pedal sensor

Claims (15)

1. Drive arrangement of a motor vehicle, comprising a drive motor which can be brought into operative connection via an interposed friction clutch with a downstream manual transmission, and with an actuating device for automated actuation of the clutch, which is controlled by an associated control device, which is at least one inserted Signals representing driving gear and driving and brake pedal actuation and the operation of the internal combustion engine and the driving speed indicating signals are supplied, characterized in that the control device ( 13 ) comprises a module ( 14 ) for controlling a creeping movement of the motor vehicle, which at least when the motor vehicle is still stood or almost standstill, is detected when the accelerator pedal is not actuated and he is familiar with the engaged gear and when the drive motor is in operation, the control device ( 13 ) for loading when the module ( 14 ) is activated eitstellung the transmission of a predetermined predetermined torque on the downstream transmission ( 21 ) is controlled. 2. Drive arrangement according to claim 1, characterized, that the predetermined torque in a range of values, preferably 8 to 15 Nm lies. 3. Drive arrangement according to claim 1 or 2, characterized in that the control device ( 13 ) is provided at least one load indicating the sensor ( 43 ), and the predetermined torque is predetermined depending on the known load state. 4. Drive arrangement according to at least one of the preceding claims, characterized in that the control device is assigned at least one sensor indicating a road gradient ( 41 ), and the predetermined torque is predetermined by the detected inclination of the road. 5. Drive arrangement according to claim 1, characterized in that an electromotive actuator ( 12 ) is provided as the actuator ( 11 ). 6. Drive arrangement according to at least one of the preceding claims, characterized in that the actuator ( 11 ) is driven corresponding position for taking the predetermined moment, and that in the control device ( 13 ) stored te, establish the relationship between actuator position and transmitted torque the characteristics are adapted to the current state of wear of the friction clutch ( 9 ). 7. Drive arrangement according to claim 1, characterized in that in the module ( 14 ) creep, the engine torque is increased by the amount of the clutch via the Rei ( 9 ) transmitted torque plus the friction torque in the friction clutch ( 9 ) decreasing. 8. Drive arrangement according to claim 7, characterized in that upon entry into the module ( 14 ) creep the drive motor ( 3 ) to provide a to the frictional torque and the transmitted via the friction clutch Mo element is controlled plus an offset. 9. Drive arrangement according to claim 8, characterized, that the offset is reduced with the onset of vehicle movement, preferably is led to zero. 10. Drive arrangement according to claim 8, characterized in that in the creep mode the drive motor ( 3 ) for providing a predetermined speed of the drive motor ( 3 ) is controlled. 11. Drive arrangement according to claim 9, characterized in that in the module ( 14 ) creep at an offset value of zero or almost zero, the drive motor ( 3 ) is driven for operation at a predetermined speed. 12. A method for controlling a drive arrangement according to at least one of the preceding claims with the following steps:

• - Commissioning the drive motor (S1)
• - Detection of your vehicle standstill or subsequent standstill (S2)
• - engaging a starting gear (S3)
• - release the vehicle brake (S5)
• - Control of the actuator ( 11 ) by the control device ( 13 ) for transmission of a predetermined torque and control of the drive motor ( 3 ) to provide an increased torque (S6).

13. A method for controlling a drive arrangement according to at least one of the preceding claims with the following steps:

• - Actuation of the actuator for transmission of the predetermined torque via the friction clutch ( 9 ) after releasing the vehicle brake when the accelerator pedal ( 15 ) (S6) is not actuated.
• - Control of the drive motor ( 3 ) to provide an increased torque.

14. The method of claim 12 or 13, characterized in that the falling in of the friction clutch (9) friction power is received and with exceeding of a limit value, the clutch (9) of the module (14) Krie chen leaving completely switched on or disengaged ( S15). 15. The method according to claim 12 or 13, characterized in that the drive motor ( 3 ) is controlled in a first operating phase to provide an idle torque plus the torque transmitted via the clutch to provide a creeping torque and that in a second operating phase the drive motor for providing the idling torque, plus the torque that is transmitted via the clutch, is controlled.