DE3004930A1 - Automatic clutch system for motor vehicle - has control mechanism reacting to speeds on both sides of coupling with servo system and engaging without backlash - Google Patents

Abstract

A clutch for a motor vehicle has an automatic actuator between a drive motor and the gear box. It provides engagement without backlash. The clutch is assisted by an auxiliary force from a servo motor. The drive output of the drive motor is controlled by a servo mechanism. The speeds in front of and behind the clutch are picked up and transmitted as a signal. There is a control mechanism (21) which reacts to the speeds measured in front of and behind the clutch (3). It is used to control the servo motor (9) which actuates the clutch and a second servo motor (22) which actuates the servo mechanism (7). The control mechanism (1) is connected to the accelerator pedal (25) of the motor vehicle.

Description

Facility for automatic

Clutch actuation - The invention relates to a device for the automatic actuation of a between a drive motor and a gear A motor vehicle clutch according to the preamble of claim 1.

Automatic motor vehicle clutches are already known in which the clutch is operated, for example, by a pneumatic servomotor. However, there is a control effect only on the servomotor of the clutch in order to to cause them to engage the clutch as slowly and smoothly as possible. In contrast, there are no effects on the actuator which determines the engine output.

The object on which the invention is based is therefore to be seen in to create a device for automatic clutch actuation, the opposite the previously known designs is improved and in particular the possibility creates a largely smooth clutch engagement.

This problem is solved according to the characterizing part of the claim 1.

Characterized in that according to the invention, the control device not only the the Clutch actuating servomotor, but also a second, the actuator actuating servomotor controls is at least during the clutch actuation when driving the vehicle, for example when shifting the manual transmission from one gear to another, making sure that the clutch is not engaged a speed adjustment can take place in front of and behind the clutch, so that the coupling process takes place without jerks.

According to a further proposal of the invention, when starting up should also the control device on the second servomotor to achieve a predetermined Act on the motor speed in order to then use the first servomotor for slow gripping the clutch while keeping the set engine speed constant until it closes to act on the clutch in front of and behind the clutch when the speed is the same.

Starting the drive engine while the vehicle is moving can also be used Can be achieved using the clutch actuator according to the invention by in this operating case the first servomotor for slowly engaging the clutch is applied in such a way that a predetermined value of the engine speed change after which time is not exceeded.

Further features of the invention emerge from the subclaims.

Figure 1 of the / drawing is an embodiment of the invention shown on the basis of a schematic circuit diagram, in which with 1 a conventional Vehicle engine is designated, which has a clutch 3 with a manual transmission 2 is connected for manual engagement of the individual transmission gears. With 4 is while the engine crankshaft arranged in front of the clutch 3 and with 5 the one behind the Coupling lying transmission input shaft called. The clutch 3 is here, anyway not exclusively, as is usual with conventional vehicles, by means of a foot pedal can be actuated, but should at least alternatively also be actuated by means of an auxiliary power operated Servomotor, for example a pneumatic vacuum servomotor 9, engaged and disengaged can be. For this purpose, the servomotor 9, its membrane with the clutch actuation lever 8th is connected via a vacuum line 11 to a pneumatic control valve 10 connected, the control piston 12 of which is adjusted by a further servomotor 20 will. The piston shoulder provided between the piston collars 13 and 14 connects 15 the vacuum line 11 either with the line connection leading to the atmosphere 16 or with a vacuum line 17 leading to a vacuum source. A vacuum reservoir 19 is provided here as a vacuum source via a Check valve 18 with the suction line 6 of the vehicle drive engine designed as a gasoline engine 1 is connected. A conventional throttle valve 7 is located in this intake line 6 intended as an actuator to control the drive power of the drive motor, which in turn is actuated by a servomotor 22. The servomotor 22 is also as the servomotor 20 for actuating the pneumatic control parts 10 of a Control device 21 controllable with various transducers for detection the respective operating state of the vehicle is connected. So are two speed sensors 27 and 28 are provided, the speeds and accelerations of the motor crankshaft 4 and the transmission input shaft 5 to the control device 21 for further processing report, while with 24 the position of the manual transmission 2 assigned Hand shift lever 23 detecting encoder is calibrated. 26 represents the position of the accelerator pedal 25, which is also used for signal transmission the control device 21 is connected.

The function and mode of operation of the automatic according to the invention The cooling actuation device will now be explained below. Have to different operating states distinguished from one another.

be, namely the actuation of the clutch while driving Carry out the vehicle, for example, by shifting the manual transmission 2 without any force to be able to actuate the clutch while the vehicle is at a standstill and the actuation of the clutch for starting the engine by the located in the case Vehicle. In all of these operations there is essentially only the engagement of the clutch critical, while no major demands are made on the approach. This Disengagement can thereby be effected in a more simple manner be that for example, by touching the manual shift lever 23 to select a different gear the position transmitter 24, formed for example by a switch, sends a signal the control device 21 emits, on the basis of which this the servomotor 20 for adjustment of the control valve 10 is applied in such a way that the clutch 3 of the servomotor 9 is disengaged.

In your embodiment shown in the drawing is of it it was assumed that the servomotor 9 was partially subjected to negative pressure via the negative pressure line 11, i.e. when the control valve connects this line to the vacuum line 17, the clutch is actuated in the disengaging direction, while when the servomotor is acted upon 9 with atmospheric pressure by connecting the line 11 to the atmospheric pressure connection 16 the clutch is adjusted in the engagement direction.

It tl now assumed that while driving one with an inventive Clutch actuation device equipped motor vehicle by touching the The clutch 3 is disengaged with the manual shift lever, so that the gearbox 2 is free of tensile force can be switched. As soon as the i and switch lever is in the new switch position If it is released again, it inputs the position transmitter 24 to the control device 21 Signal to engage the clutch, whereupon according to the invention first the control device the servomotor 22 controls, which controls the power actuator formed by the throttle valve 7 Adjusted until the speeds measured by the speed sensors 27 and 28 in front of and behind the clutch 3 are essentially the same size. Once this is achieved is, the servomotor 20 is controlled by the control device 21 for adjusting the control valve 10 acted upon in a position in which the pneumatic servomotor 9 with atmospheric pressure is acted upon, so that the clutch 3 is quickly engaged. There at this moment no or only a very small speed difference between the engine crankshaft 4 and the transmission input shaft 5 prevails, the coupling process takes place in the weset soft smoothly.

The servomotor which actuates the power actuator 7 of the drive motor 1 22 can also be used to adjust the output on the basis of other signals used are, for example, depending on signals of the position of the accelerator pedal 25 ascertaining position transmitter 26. Also in the idle operating state this Servomotor for regulating a predetermined constant or, if necessary idling speed that varies with the operating temperature of the vehicle will. Of course, instead of the throttle valve provided in the drawing The adjusting lever of an injection pump for power control is also used as an actuator can be used.

To start the drive motor of the vehicle in motion to enable forth, the control device 21 could also be designed so that they via the servomotor 20 the pneumatic servomotor 9 to such a slow Engaging the clutch acts that a predetermined value of the engine speed change after which time. is not exceeded. The need to start the engine if the speed n1 of the engine crankshaft 4 is 0, on the other hand the Speed n2 of the transmission input shaft due to the rotating wheels greater than 0 is.

When starting the vehicle, what happens when the speed n2 of the transmission input shaft is 0, whereas the speed n1 of the engine crankshaft 4 is greater than 0 and the accelerator pedal 25 is also actuated by the driver's foot, that is to say is greater than 0, the regulating device 21 adjusts via the servomotor 22 the power actuator 7 initially so that a certain speed n1 of the engine crankshaft is achieved at which a sufficient engine torque (for example n1 = 1800 rpm) is produced. The clutch 3 can then be activated by appropriate control of the Servomotor 20 and the resulting application of atmospheric pressure to the pneumatic Servomotor 9 are engaged so slowly that a drop in engine speed n1 is prevented. However, as soon as the speed n1 drops, the closing process is started the clutch by appropriate actuation of the control valve 10 via the servomotor 20 interrupted. The simultaneous speed control via appropriate control of the servomotor 22 then ensures that with increasing engine crankshaft speed n1 the closing process of the clutch is restarted until finally at approximate Equal speed in front of and behind the clutch by finally applying atmospheric pressure to the pneumatic servomotor 9 the clutch 3 is closed.

In the figure 2 of the drawing is a signal flow diagram for the logic Realization of the control device 21 indicated in FIG. 1 is shown schematically, which is explained in more detail below.

It is at 30 a of the position of the gear shift lever 23 and the ignition switch, which is dependent on the accelerator pedal 25, is then closed, when the gearshift lever is in reverse or in first or second forward gear stands, or if the accelerator pedal is not in its rest position, so actuated is. This means at the same time that the ignition switch 30 is released Accelerator pedal and when the gearshift lever is in the third, fourth or possibly is open in a further gear, the ignition and / or fuel supply so it is turned off.

At 31, the ignition switch 30 is one of the position of the clutch 3 dependent changeover switch connected downstream which, when the clutch is open, the output 31a, on the other hand, controls output 31b when the clutch is closed. At the exit 31a subsequent switch 32 should be switchable depending on the engine speed and at an engine speed of, for example, below 500 rpm - which is practically a stationary motor - the output 32a, on the other hand at higher speeds the Activate output 32b. Output 32a is followed by the position of the gearshift lever 23 dependent switch 33, which has an output leading to a starter motor 34 33a, which is selected in reverse gear and in first and second forward gear is, while in the other forward gears the output 33b is applied.

35 denotes a changeover switch, the outputs 35a to 35c of which are dependent can be selected from the level of the measured motor accelerations.

The output 35a is activated when the angular acceleration the engine crankshaft is greater than a predetermined acceleration value, which depends on the position of the accelerator pedal, for example stepwise increasing, can be set. In this position of the switch 35 is a signal output 37 controlled, which emits a pulse to open the clutch. The switch On the other hand, 35 is in position 35c when the angular acceleration of the motor falls below the predetermined acceleration limit value, whereby a signal output 36 for Activation of the clutch 3 or the control slide 10 from FIG. 1 with a closing pulse is applied. On the other hand, it corresponds exactly to the angular acceleration of the motor the specified limit value, then output 35b leading to nothing is selected.

From the previously described part of the signal flow diagram of the figure 2 it follows that when the clutch is open and the engine is practically stationary when stepping down the accelerator pedal in reverse as well as in first and second forward gear automatically the starter motor is operated, while in the position of the manual shift lever in a higher gear the clutch to start the engine by the in doubt vehicle in motion in compliance with a specified, if necessary accelerator pedal-dependent variable engine acceleration is closed.

If, on the other hand, the motor is already running, then the switch 32 is in the Position 32b, so that a changeover switch 38 is activated, the position of which is dependent is on the level of the transmission input speed, i.e. the speed behind the Coupling. If this is smaller than a predetermined one, for example again step-shaped depending on the position of the accelerator pedal increasing reference value, then lies the operating state of the start-up before, and the output 38a of the switch 38 is selected.

If, on the other hand, the specified reference speed value is reached or exceeded, then only the clutch should be engaged, that is to say the one for realizing a freewheeling operation The clutch disengaged while coasting or shifting gears should be automatically closed again will. In the latter case, output 38b of switch 38 is selected for this purpose.

In both cases, however, in addition to actuating the clutch, The throttle can be adjusted in this way by adjusting the speeds in front of and behind the coupling a soft, bump-free Coupling process to ensure. For this purpose, the signal lines branch behind the two Outputs 38a and 38b each to two changeover switches 39 and 40 and 41 and 42, respectively each of which has the clutch actuation signal outputs 36 and 37 and the other Throttle valve actuation signal outputs 47 and 49 acted upon. The position of this Changeover switch 39 to 42 depends essentially on the size of the measured Engine speed.

So the switch 39 selects the output 39a when the engine speed smaller, on the other hand the output 39b when it is greater than that already for the changeover switch 38 used for comparison purposes and dependent on the accelerator pedal position Reference speed value. The two outputs 39a and 39b are via signal lines 46 and 48 are connected to the signal outputs 47 and 49, of which the output 47 a pulse to close and the output 49 to open the throttle valve gives away.

In contrast, the changeover switch 40 acts on the signal output that closes with the clutch 36 connected output 40a if the engine speed is greater than 98, for example % of the reference speed and applies the clutch release signal output 37 connected output 40b, if the engine speed is less than 95% of the reference speed is.

The changeover switch 41 also has two outputs 41a and 41b, one of which the first is selected when the engine speed is less than 95% or greater than 105% of the transmission input speed, while the second output 41b is activated is when the engine speed is within a tolerance range of 5% of the transmission input speed is equivalent to. While the output 41a with the signal output to the clutch opening 37 leading signal rail is connected, the output 41b is connected to the clutch closing signal output 36 connected.

The changeover switch 42 finally switches to the one with the throttle valve opening signal output 49 connected output 42a when the transmission output speed is greater than the Motor speed plus a correction factor that takes into account the motor acceleration of 50% of the first derivative of the engine speed with respect to time. Of the On the other hand, output 42b connected to the throttle valve closing signal output 47 becomes selected for gearbox input speeds that are lower than the above motor speed comparison value.

At 43 there is still another which detects the state of the gear shift lever Switch indicated that is closed as soon as the manual lever is removed from the hand of the vehicle driver is touched for the purpose of performing a shift. This switch also acts on the signal emitting clutch release pulses exit 37.

The above explanation essentially corresponds to the signal flow to implement the combined automatic shown in FIG. 1 of the drawing Clutch and throttle actuation controls.

In addition, the signal flow for an in Automated throttle valve actuation depending on the accelerator pedal position indicated. For this purpose, output 31b of the clutch-position-dependent switch is used 31, which is selected when the clutch is closed, with a switch 44 with four different signal outputs 44a to 44b connected, which are in different positions the accelerator pedal ls are controlled. This is how the output becomes when the accelerator pedal is released 44d selected, the one with the signal output 47 for the delivery of throttle valve closing pulses is connected, while when the accelerator pedal is essentially depressed, the output 44a is applied, which is connected to the throttle valve opening signal output 49 is. The two middle outputs 44b and 44c of the switch 44 are middle Accelerator pedal positions assigned and connected to a control unit 50, to which Signal outputs 51 and 52 control pulses for a deferred programmed control of the throttle valve servomotor 22 from FIG. 1, for example as a function of the respective engine speed.

L e r s e i t e

Claims (7)

A PROVERBS 1. Device for the automatic actuation of a between a drive motor and a transmission of a motor vehicle clutch arranged with a servomotor that actuates the clutch, a servomotor the actuator controlling the drive power of the drive motor and with transducers for recording the speeds in front of and behind the clutch, characterized in that that a control device (21) is provided, which depends on the before and speeds measured behind the clutch (3) the servomotor that actuates the clutch (9) and a second servomotor (22) which actuates the actuator (7). 2. Device according to claim 1, characterized in that the control device (21) at speeds different from 0 first the actuator (7) actuating second servomotor (22) controls in such a way that the engine speed (speed in front of the clutch) is essentially the same size as the transmission input (1 speed (speed behind the clutch), and then the first servomotor (9) to engage the clutch (3) is applied. 3. Device according to claim 1, characterized in that the control device when starting the vehicle (engine speed greater than 0, Gear input number = § 0) first the second servomotor (22) to achieve a predetermined engine speed controls and then the first servomotor (9) to slowly grasp the Clutch (3) while keeping the engine speed constant until the clutch closes applied in front of and behind the clutch when the speed is the same. 4. Device according to claim 1, characterized in that the control device (21) to start the drive motor (1) while the vehicle is moving (engine speed = 0, gearbox input speed greater than 0) the first servomotor (9) for slow engagement the clutch (3) is applied in such a way that a predetermined value of the engine speed change after which time is not exceeded. 5. Device according to one of claims 1 to 4, characterized in that that the first servomotor (9) is a pneumatic one, the servomotor with the atmosphere or a control valve (10) connecting a vacuum source (19) is connected upstream, that of a third servomotor (20) which can be controlled by the control device (21) is actuatable. 6. Device according to one of claims 1 to 5, characterized in that that the control device (21) detects the position of the accelerator pedal (25) with a Encoder (26) is connected. 7. Device according to one of claims 1 to 5, characterized in that that the control device ~ (21) with a the position of the gear shift lever (23) detecting encoder (24) is connected.