DE2500330A1 - MOTOR VEHICLE TRANSMISSION WITH AUTOMATIC CLUTCH CONTROL SYSTEM - Google Patents

Description

Patent attorneys
Dipl.-Ing.W. Beyer Dipl.-Wirtsch.-Ing. B. Jochen)

Prankfurt am Main Staufenstr.

Note: \

Ford-Werke AG

Cologne-Deutz

Ottoplatz 2 ί, ^

Automobile transmission with an automatic clutch control system.

The invention relates to a motor vehicle transmission with automatic Clutch control system and is characterized according to the invention by

a) a vehicle clutch that can be disengaged and disengaged as a function of electrical control signals,

b) a clutch actual position signal generator for generating the actual position of the Coupling reproducing signal,

c) a motor signal generator for generating a signal representing a motor parameter,

d) Means for generating a clutch sol lstel signal off, the motor parameter signal, where the Clutch nominal position signal of the just disengaged Coupling corresponds when the engine parameter has its minimum value, and with the increase of the motor parameter through partial settings

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Fo 8633 / 6.1.1975

to finally indicate a full reset when the motor parameter is below its maximum value, and

e) a comparator circuit (38) for comparing the actual clutch position signal with the desired clutch position signal and to create a control signal which causes the clutch to move into its set division.

The engine parameter is preferably the accelerator pedal position; however, other parameters can be used to indicate engine torque, such as engine speed or the position of the fuel rack.

An embodiment of the invention is described below in connection explained in more detail with the drawing. Show it:

Fig. 1 in a schematic representation of an electronic Clutch control system according to the invention,

Fig. 2 is a circuit diagram of the system of Fig. 1,

3 shows the actual clutch position signal transmitter in a schematic representation and

Fig. 4 is a diagram to illustrate the dependency between the. Accelerator pedal position and clutch position.

A vehicle coupling Io connects a diesel engine with one Change gear in a heavy truck. A clutch release lever 11 is mechanically connected to a piston that is displaceable within a servo cylinder 12.

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·) To the right

A piston valve 13 is between a supply line 14 for hydraulic fluid and the servo cylinder 12 switched on. The valve piston 15 of the valve 13 is of a Plunger coil electromagnet 16 either 'to connect the servo cylinder 12 to the supply line' 14 and thereby to the Disengagement of the clutch or rigich left; "ztöri detaching the Supply line and venting of the 'ServozyiindeT' via a Outlet line 17 moves, causing the clutch to engage able.

The plunger coil electromagnet 16 and thus the clutch Io are controlled by an electronic Küpplürigssteuersystem 18 controlled, which responds to electrical signals, which the Kupllungs-Iststellung, the position of the accelerator pedal, the Engine speed, the speed of the clutch output shaft and show the driving speed. If the clutch control system is used in conjunction with an electronically controlled transmission shift system, the clutch control system will also respond to overtaking signals from the transmission shift system when this requires the clutch to be engaged or disengaged.

A clutch actual position signal is on a line 2o created by an actual position signal generator 21, which consists of a variable resistor connected between ground and a reference voltage V- and a wiper exists, which moves together with the clutch release lever 11 over the resistance.

The engine speed Nl, the clutch output speed N2 and the driving speed N3. are indicated by electrical signals generated by signal generators 22, 23 and 24.

Furthermore, an accelerator pedal position signal is provided by a variable resistor 25 associated with the accelerator pedal is mechanically connected. The variable resistance 25

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is connected between ground and the reference voltage V, and a wiper 26 moved by the accelerator pedal grips a potential between zero and V- in accordance with the accelerator pedal position away.

One end of the plunger coil electromagnet 16 is at ground potential and the other end connected to the junction between two resistors 85 and 86. An electronic one Switch 27 applies resistor 85 to a potential of plus 12 volts, and an electronic switch 28 connects resistor 86 to a potential of minus 12 volts. The engagement and disengagement of the clutch is indicated by the signal a line 29 is determined. If there is a signal on line 29, switch 27 is turned on and it Current flows through the immersion coil from plus 12 volts to ground. If, on the other hand, there is no signal on line 29, A converter 3o switches on the electronic switch 28, and current flows through the plunger coil in the opposite direction Direction from ground to minus 12 volt potential. The order is made so that a signal on the line 29 the valve piston 15 to the right to engage the clutch and no Signal on line 29 causes valve piston 15 to move to the left to disengage the clutch.

An oscillator 31 operates a square wave generator with a fixed frequency of about 200 Hz. An analog signal on a line 33 at the input of the square wave generator 32 determines the pulse-space ratio the generator output on line 34. The output line 34 of the square wave generator is connected to the input line via an AND gate 35, an AND gate 36 and an OR gate 37 29 of a drive circuit for the plunger coil electromagnet 16 connected. Thus, when AND gates 35 and 36 are open, the plunger coil is alternately in one or the other

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Direction driven and moves in the direction for engaging or disengaging the clutch in accordance with the pulse-space ratio of the drive signal.

The actual clutch position signal on line 2o is applied to one input of a comparator 38 · The the other input of the comparator 38 receives a nominal position signal on a line 39. If the actual position signal on the line 2o below the target position signal on the Line 39 is located, the comparator 38 supplies a signal to a line 33 which represents the pulse-space ratio the pulse train generated by the square wave generator 32 increases, causing the clutch to move further into the engaged position · When the actual position signal on line 2o is greater than the desired position signal on line 39, comparator 38 reduces the signal on line 33 and thereby reduces the pulse-space ratio of the square wave signal, which is given to the drive circuit for the plunger coil, whereby the The clutch is caused to move in the DISENGAGE direction the clutch target position compared and an adjustment made until the actual position corresponds to the target position.

If on the line 29 a signal for longer than a predetermined If a period of time is pending, the clutch is fully engaged. Time delay gate 4o is on line 29 connected and opens only when the signal on line 29 is present for longer than the predetermined period of time. The output signal of the gate 4o is thus only present on a line 41 when the clutch is fully engaged is. The full-engagement clutch signal on the line is used to ensure that the actual position signal on line 2o to be entered into a fully reset memory 42 so that

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this memory constantly stores a signal which corresponds to the full adjustment of the clutch. The full reset signal on a line 43 is fed to a subtracting circuit 44 which has a constant voltage subtracts according to a predetermined distance X, which is covered by the clutch from its fully engaged position must be in order to just separate the friction members of the clutch. This position is shown in FIG. It deserves Note that when the clutch wears, the signal stored in memory 42 is reduced, however, the output of the subtracting circle 24 always reflects a clutch position in which the friction members are just separated. The clutch disconnect position signal generated by subtracter circuit 44 on line 25 is fed to one input 46 of an adder circuit 47. The accelerator pedal position signal on line 26 is to the other input 45 'of the adder circuit. The exit of the adder circuit 47 on the line 48 biAdet the clutch setpoint position signal which is fed to the line 39. A maximum value limiting circuit 49 limits the steepness of the rise of the signal on line 48 to a predetermined one Value which defines the maximum limit of the extent to which the clutch shifts in the direction of engagement can be.

The relationship between the desired clutch position signal on lines 48 and 39 and the accelerator pedal position signal is plotted in FIG. When the accelerator pedal is out of its idle position is moved out, the first 5 ° movement has no effect. The nominal clutch pitch is the disconnected position according to the signal on line 45. When the accelerator pedal adjustment increases over 5 °, the clutch target position signal increases linearly with the adjustment of the accelerator pedal, in order to finally reach a level corresponding to the fully engaged clutch, immediately before the accelerator pedal is fully

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is constantly depressed.

If, during operation, the vehicle starts moving from a standstill, the gate 35 is initially closed. A level detector circuit 50 generates no output because the accelerator pedal is in its idle position and an AND element 51 is disabled because the clutch output speed N2 is not equal to the engine speed N1. If the driver depresses the accelerator pedal beyond 5 °, the level detector circuit 5o reacts by generating a signal on a line 52 which runs through an OR gate 53 and outputs the AND gate 35 for the passage of the output of the square wave generator 32. The adder circuit 47 adds the accelerator pedal position signal at wiper 26 to the clutch striker position signal on line 45 to produce the clutch setpoint position signal on line 39, and the clutch is adjusted to a position corresponding to the setpoint position in the manner described above. If the driver depresses the accelerator pedal more or less, the clutch follows in the appropriate position. When torque is transmitted by the clutch, the vehicle is accelerated progressively from standstill until the engine rotation speed Nl of the output speed corresponds to the ^K N2 upplung. At this point the signals on lines 54 and 55 are the same, and a comparator 56 produces an output signal on line 57. Provided that the engine speed is greater than 400 RPM so that a level detector circuit 58 produces an output signal on line 59, and the driving speed is more than 2 km / h, so that the level detector circuit 3o generates an output signal on a line 61, an AND element 62 causes an output which is passed to an AND element 51 via an OR element 63. As a result, the AND element 51 generates an output signal on a line 64 as soon as the two parts of the clutch rotate at the same speed. This signal on the line 64 actuates a switch 65 which switches off the adder circuit 47

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and another adder circuit 66 connects to the comparator 38.

For reasons described later, the adding circuit already generates a desired clutch position signal corresponding to a clutch fully engaged, and the clutch will instantly move to its fully engaged position. The signal on the line 64 is also fed to the OR gate 53, so that the AND gate 35 remains enabled, even if the Driver takes his foot off the accelerator and so no longer a signal on line 52 remains. This ensures that the engine braking clutch remains engaged until either the engine speed falls below 400 rpm or the driving speed drops below 2 km / h, in which case the AND gate 62 no longer generates an output signal, that AND gate 51 no longer produces an output signal and a signal on line 64 collapses. This transfers the control of the clutch position to the accelerator pedal position sender, since the adder circuit 47 again to the Comparator 38 is turned on. If the accelerator pedal is not depressed, the clutch will be in the disengaged position adjusted.

In the exemplary embodiment described here, there is precaution taken for an alternate engagement of the clutch, which is used when the clutch is engaged after a gear change should be indented again. The gear shift logic circuit causes a double end clutch gear change and controls one clutch release line one after the other 67, a neutral position selection line 72, and a clutch engagement line 68. When a signal to the line 6 7 is given to indicate that the clutch is to be disengaged, an inverter 69 no longer generates an output signal so that AND gate 36 no longer produces an output signal and no longer produces a signal

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is present on the line 29, and moves the plunger coil in the disengaging direction and staying there, causing the clutch to move into the disengaging position to move. When the signal on line 67 as If the indication that the clutch is to be switched on again is removed, a signal increase generator became 7o allowed. The clutch moves into the disconnected position because the adding circuit 66 is connected to the comparator 38 is (the signal on line 64 is due to the self-locking Connection 71 is present opposite the OR gate 73), and the clutch moves into the disconnected position When the output of the signal increase generator 7o increases, the desired clutch position signal on line 39 also increases, causing the clutch to be in its engaged position is adjusted with a predetermined amount, which of the Slope of the signal $ of the signal increase generator 7o corresponds. This slope is selected so that it allows a smooth re-engagement of the clutch after the Transmission unifunction results.

The clutch apply line 68 is used to rapidly engage the clutch for neutral selection during the double end coupling and synchronization of the Transmission when changing gear.

To ensure that the clutch is engaged when changing gear is not accidentally disengaged, an OR gate 74 supplies a signal to an OR gate 63 to to ensure that the AND gate 51 does not switch off, whenever the clutch release line 67 or the clutch release line 68 is controlled.

Claims Po 8633 / 01.06.1975

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Claims (12)

Claims 1. Motor vehicle transmission, marked by a) a vehicle clutch (lo) that can be disengaged and engaged as a function of electrical control signals, b) a clutch actual position signal generator (21) for generating the actual position of the Coupling reproducing signal, c) a motor signal generator for generating a signal representing a motor parameter, * Sr d) Means for generating a desired clutch position signal from the motor parameter signal, where the Clutch »target position signal corresponds to the clutch that has just been disengaged, if the engine parameter has its minimum value and with the increase in the motor parameter due to partial adjustments to finally indicate a full reset when the motor parameter is below its maximum value, and e) a comparator circuit (38) to compare the Actual clutch position signal with the target clutch position signal and to create a control signal, which causes the clutch to move into its desired position. Fo 8633 / 6.1.1975 509828/0272 2. Transmission according to claim 1, characterized by such a design that the clutch (Io), regardless of the magnitude "of the clutch command position signal, to its fully engaged position is moved when the engine speed (Nl) is substantially equal to the output speed (N2) of the clutch. 3. Transmission according to claim ?, characterized by such a design that the desired clutch position corresponds to the full E ^ n ^ cks division of the clutch when the motor parameter is close to its maximum value is. 4. Transmission according to claim 2 or 3, since you r c h g e -kennzeich net »that de * · motor signal generator (25, 26) generates a signal representing the position of the accelerator pedal. 5. Transmission according to claim 2 or 3, characterized in that the motor signal generator (22) a signal reproducing the engine speed (Nl) is generated. . 6. Transmission according to one of the preceding claims, g e -ke η η ze i c h η e t d u r c h a clutch reset memory (42) wherein the clutch target position signal can be generated by combining the engine parameter signal .. 7. A transmission according to claim 6, characterized in that the output of the clutch actual position signal generator (25, 26) in the clutch engagement position storage (42) is entered when the clutch is in the fully engaged position. Fo 8633 / 6.1.1975, 509825/0272 8. Transmission according to claim 6 or 7, characterized in that that the motor parameter signal and the difference between the full provision the clutch and the clutch position just disengaged reproducing predetermined constant signal added to the output of the memory (42) to produce the clutch setpoint signal. 9. Transmission according to one of the preceding claims, characterized by a second Clutch target position ^ signal generator to create a clutch target position signal, which from corresponding to the clutch position just engaged Value to a value corresponding to the fully engaged clutch position with essentially uniform rate of increase regardless of the value of the motor parameter increases, as well as switching means (65) for selectively connecting the first or the second clutch setpoint position signal generator to the Comparator circuit (38). 10. Transmission according to claim 9, marked ze ichnet by control means for actuating the switching means (65) for the purpose of connecting the first clutch target position signal generator to the comparator circuit only when starting or driving at low speed. 11. Transmission according to one of the preceding claims, characterized by a clutch servo cylinder (12) and one on the electrical control signals responsive, electrically operated valve (13) for connecting the servo cylinder (12) to a Pressure medium source for disengaging the clutch or a Vent to allow clutch engagement. Po 8633 / 6.1.1975 509828/0272 12. Transmission according to claim 11, geke η ή ζ eich η et by a square wave generator (31, 32) responsive to the output of the square wave generator drive circuit (35, 36, 37, 29, 3o, 2 ?, 28) for actuating the valve (13> in one ^ direction during the duration of the square wave pulse and in the other direction between the R.chtöckwelleinipülsen, whereby the pulse-gap ratio of the square wave pulse generator and thus the direction of the coupling movement can be controlled by the comparator circuit (38). Fo 8633 / 6.1.1975 509828/0272 Blank page -> '■■■ ■ * ■