JP3560363B2 - Automatic clutch control method for starting and ending a coasting phase of a vehicle - Google Patents

Description

[0001]
[Industrial applications]
According to the invention, a computer-operable clutch is provided between the internal combustion engine and the transmission, which can be disengaged to start the coasting operation phase of the vehicle, and the accelerator pedal angle in the closing direction A method for controlling the automatic decoupling of the internal combustion engine from the power train of the motor vehicle, wherein exceeding a predetermined value of the temporal change of the internal combustion engine is regarded as a control amount for disengaging the clutch; In between, a computer-operable clutch is provided, which controls the automatic connection of the internal combustion engine to the vehicle's power train, which can be engaged to end the coasting phase of the vehicle. About the method.
[0002]
[Prior art]
A power train and a method for driving a motor vehicle are known from DE-OS 27 48 697 of the applicant. In this case, the drive engine is disconnected from the power train in the coasting operation phase and stops. Such a coasting phase occurs when the engine is driven by wheels driven by the vehicle mass. In this case, the wheel has a higher rotation speed than the rotation speed corresponding to the state of the accelerator pedal. If the engine is disconnected from the power train and stopped in such a coasting operation phase, the overall fuel consumption of the vehicle is significantly reduced without deteriorating the running characteristics.
[0003]
Furthermore, German Patent Application DE 30 26 489 A1 discloses a power train of the above-mentioned type for motor vehicles. In the case of this power train, the engine is disconnected from the power train when the temporal change of the accelerator pedal angle or the throttle valve angle in the closing direction exceeds a predetermined value. By using the predetermined limit value for the change of the throttle valve or the accelerator pedal over time in the closing direction, the expected coasting condition easily occurs. Thereby, the clutch can be disengaged very quickly to disconnect the engine. It is furthermore proposed in the above specification that the accelerator pedal angle or the throttle valve angle is arranged in a table in a computer memory, and that each adjustment angle corresponds to the inertia rotation speed of the engine. The inertia rotation speed is the rotation speed of the engine when the throttle valve or the accelerator pedal is at a predetermined adjustment angle in a state where no load is applied (that is, a state where the clutch is disengaged).
[0004]
The manipulated variable by detecting the change over time of the angle between the throttle valve and the accelerator pedal can be advantageously used for disconnecting the engine at the start of the coasting phase, but this manipulated variable is used at the end of the coasting phase. Not available to connect the engine to the. This is because the condition of the throttle valve and the accelerator pedal do not give any information on the actual engine speed which is important for the connection process. Furthermore, the known detaching methods do not provide a sufficiently gentle and comfortable detachment. This is because, until now, only quick information regarding the impending coasting operation phase can be inferred from the temporal change of the throttle valve angle or the accelerator pedal angle.
[0005]
[Problems to be solved by the invention]
The object of the invention is to provide a method for automatically operating a clutch for starting and ending a coasting phase of a motor vehicle of the type mentioned at the outset.
[0006]
[Means for Solving the Problems]
The problem is that while driving a car, the computer periodically detects the accelerator pedal state, its temporal change, and the input shaft speed of the transmission, and calculates the appropriate coasting speed of the engine based on the detected value of the accelerator pedal angle. Or read from a table in computer memory, the clutch is disengaged when the coasting speed falls below the transmission input shaft speed, thereby disconnecting the engine from the remaining powertrain and in the closing direction. When the detected temporal change in the accelerator pedal angle exceeds a predetermined value, a correction amount corresponding to the detected value of the temporal change in the accelerator pedal angle is calculated by a computer or from another computer memory. Is read out, and this correction amount is added to the detected transmission input shaft rotation speed, and the corrected transmission input shaft speed is corrected. The shaft speed is determined and then compared to the corrected transmission input shaft speed for coasting speed, and the clutch is disengaged when the coasting speed falls below the corrected transmission input shaft speed. Or during operation of the vehicle, the computer periodically detects the engine speed and its change over time, and when the engine speed exceeds the transmission input shaft speed, the clutch is disengaged and detected. When the temporal change of the engine speed exceeds a predetermined value, a correction amount depending on the temporal change of the engine speed is calculated by the computer or read out from the computer memory, and the correction amount continues. The corrected transmission input shaft speed is subtracted from the detected transmission input shaft speed to determine a corrected transmission input shaft speed, and then the engine speed and the corrected transmission speed are calculated. Compared force shaft speed to each other, the engine speed is at above the rotational speed corrected transmission input shaft, is solved by the clutch is linked. Advantageous embodiments of the method are described in the dependent claims.
[0007]
According to the present invention, in the case of the engine disconnection process, the engine coasting speed derived from the position of the throttle valve or the accelerator pedal and its temporal change, and in the case of the engine connection process, the engine speed and its It is based on the realization that temporal changes are used as a control variable for operating the clutch between the drive engine and the transmission. When the inertia rotation speed is used, when the position of the throttle valve or the accelerator pedal in the closing direction changes rapidly, the disconnection can be started quickly in accordance with the change speed. For this purpose, an offset value dependent on the adjustment angle change speed is added to the transmission input shaft speed measured by the control computer, resulting in a corrected transmission input shaft speed. A comparison between the transmission input shaft speed and the coasting speed, which is always performed by the control computer during the operation of the vehicle, quickly confirms that the coasting speed is below the corrected transmission input shaft speed, and thereby the clutch Can be cut faster and more comfortably than before.
[0008]
Similarly, when the engine is connected-in this case, if the engine speed changes rapidly, for example by quickly depressing the accelerator pedal, the engine speed of the unloaded engine increases-the engine speed is measured. The offset value depending on the change speed is subtracted from the actual speed change input shaft speed.
[0009]
In this case as well, the control computer periodically compares the engine speed with the corrected transmission input shaft speed and recognizes that the engine speed exceeds the corrected transmission input shaft speed. Therefore, the connection process of the engine can be started comfortably and quickly depending on the changing speed of the engine speed. This quick connection of the engine to the vehicle's power train is important when dangerous situations occur, for example, during the coasting phase, where the vehicle speed needs to be increased quickly.
[0010]
【Example】
The present invention will be described based on examples. To this end, the drawings are attached to the specification.
[0011]
FIG. 1 shows a power train of a motor vehicle. In this case, 1 is a drive engine and 2 is a transmission. The engine 1 and the transmission 2 are connected to each other via a clutch 3. This clutch is fixed to the crankshaft 7 of the engine and the input shaft 8 of the transmission. The power train has a transmission output shaft 9 on the driven side. The differential gear 4 is driven by the transmission output shaft. Two drive shafts 10, 11 extend from the differential device 4. Drive wheels 5, 6 are fixed to the end of the drive shaft.
[0012]
A control computer 12 is attached to the power train. The control computer has at least one memory 13. The control computer is connected to sensors 14 and 15 for the engine speed and the speed of the transmission input shaft 8 via data inputs not shown in detail. The adjustment angle of the throttle valve or accelerator pedal 16 is detected by a sensor 18 and signaled by the computer 12. Further, when the accelerator pedal 16 is released by releasing the accelerator pedal 16, the sensor 17 is provided so that the computer 12 can recognize whether the coasting operation has been started or whether the normal shift operation is performed. Speed change information can be supplied to the computer via the CPU.
[0013]
Driving a car, the computer 12 is coasting speed of the engine from the information of the accelerator pedal position (free rotation speed) N _FR periodically detect. This coasting speed is read from the computer 12, in particular from the computer memory 13. In this computer memory, the link between the accelerator pedal angle or the throttle valve angle and the coasting speed of the engine is arranged in a table format. In another embodiment of the present invention, the inertia rotation speed can be calculated by the computer 12 by mathematical association with the accelerator pedal angle.
[0014]
As can be seen from Figure 2, at time t _0, and information about the actual coasting speed N _FR, actual transmission input shaft rotational speed N _GE is subjected to a computer. The two speed values are constantly compared with each other by the computer during operation of the vehicle. When coasting speed N _FR is less than the rotational speed N _GE gearbox input shaft, it is ensured that the vehicle operator attempts to start a coasting operation phase by the return of the accelerator pedal in the closing direction. This is reached as soon as the time t _2, the control computer 12 switches the clutch 3, disconnect the engine 1 from the power train.
[0015]
In addition to the throttle valve angle or the accelerator pedal angle, the control computer periodically detects the temporal change in the manipulated variable. In the control computer almost time t _1, over a pre-determined value, confirms the rapid temporal changes of the deflection angle of the accelerator pedal in the closing direction, conforming rotational speed value to a change speed stored in another computer memory , The computer looks for. This speed value is added to the transmission input shaft rotational speed N _GE measured at time t _1.
[0016]
Then, the transmission input shaft rotation value N ′ _GE corrected in this way is compared with the actual coasting speed N ′ _FR (t ₁ ) detected from the accelerator pedal position. Coasting value N below the _{GE 'FR} transmission input shaft value N is calculated' as soon as the clutch can be opened quickly and adapted to the varying rate of the accelerator pedal angle. This early detection of the coasting phase to be started allows the engine to be disconnected from the power train faster than before and with improved shifting comfort.
[0017]
When the vehicle is moving at the end of the coasting phase and the engine is reconnected to the power train to accelerate the vehicle above the current speed, the accelerator pedal or throttle valve swing and its time Changes are not available for control of the clutch auto-engagement process. Because they do not give information about the actual engine speed. As shown in FIG. 3, the vehicle moves in time t ₀ the coast operating speed. This coasting speed can be ascertained by the value N _GE at the transmission input shaft. At this point, since the accelerator pedal has already been depressed in the release direction, the starter 19 of FIG. 1 starts the engine and brings it to its idling speed _NL .
[0018]
Pressing slowly accelerator pedal, the engine rotational speed N _M is increased slowly. The engine rotational speed gradually approaches to the transmission input shaft rotational speed N _GE, above at time t _2. During the operation phase also, the control computer 12 always detects the transmission input shaft rotational speed N _GE and the engine speed N _M. By constantly comparing the two speed control computer 12 confirms that at time t ₂ the engine rotational speed N _M exceeds the number of rotation transmission input shaft, an end of the coast operating phase by connecting the clutch 3 Start.
[0019]
Until the clutch is engaged completely, since some time has elapsed, until the engine rotational speed N _M is transmitted to the transmission input shaft rotational speed at the time point t _3, the engine rotational speed N _M is the transmission input shaft rotates at the so-called over-swing It will be higher than the number N _GE .
[0020]
To shorten the connecting process of the engine at the end of the coasting operation phase, the control computer in accordance with the present invention, always to detect the temporal change of the engine rotational speed N _M when driving a car. That is, by the driver of the car steps on very quickly the accelerator pedal, when you want quickly terminate coasting operation phase, which appears in relatively rapid rise in engine speed by curve N _'M.
[0021]
When the control computer confirms that exceed pre-determined limits on the engine rotational speed N _'M at approximately time t _1, for the control computer suitable engine speed, transmission input shaft from the table stored in the computer memory looking for a correction value of the rotational speed _{N GE.} The correction value is subsequently because it is subtracted from the transmission input shaft rotational speed N _GE measured at time t _1, the corrected transmission input shaft speed N _"GE for connection phase are obtained. Indeed "when compared with the _GE, the control computer 12, the transmission input shaft the engine speed is corrected rotational speed N" detected engine rotational speed N _'M and the corrected transmission input shaft rotational speed N _GE Is exceeded, the engine is advantageously connected by engaging the clutch 3.
[0022]
For the method and the connecting and disconnecting process of the engine according to the invention, the speed at which the engine is connected or disconnected depends on the temporal variation of the selected manipulated variable, i.e. the temporal variation of the adjustment angle of the accelerator pedal or throttle valve or the engine speed. It is important to rely on the temporal change of Furthermore, it is clear that the shift lever information of the sensor 17 is not required for the start or end of the coasting phase of the motor vehicle. The shift lever information is used as a control variable for starting the engine only when the coasting operation phase is continued until the vehicle stops and it is desired to continue from the stopped state.
[0023]
【The invention's effect】
The method according to the invention has the advantage that the connection and disconnection of the engine during coasting can be performed easily, comfortably and quickly without shock.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a powertrain with a control computer and a measurement sensor.
FIG. 2 is a schematic diagram showing the progress of the rotational speed with respect to the time when the engine is disconnected.
FIG. 3 is a view similar to FIG. 2 for an engine connection process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Transmission 3 Clutch 4 Differential device 5, 6 Wheel 7 Drive shaft 8 Transmission input shaft 9 Transmission output shaft 10, 11 Drive shaft 12 Control computer 13 Computer memory 14, 15 Speed sensor 16 Accelerator pedal 17 Shift Lever sensor 18 Accelerator pedal sensor 19 Starter t Time N Rotation speed N _GE transmission input shaft rotation speed N ' _GE corrected transmission input shaft rotation speed N " _GE corrected transmission input shaft rotation speed N _M Engine rotation speed N' _M corrected engine speed N _FR inertial speed N ' _FR corrected inertial speed _{NL L} idling speed

Claims (3)

A method for controlling automatic disconnection of an internal combustion engine from a vehicle power train, comprising:
Between the internal combustion engine and the transmission there is provided a computer operable clutch which can be disengaged to initiate the coasting phase of the vehicle,
In a method in which exceeding a predetermined value of the temporal change of the accelerator pedal angle in the closing direction is regarded as a control amount for disengaging the clutch,
While driving the car, the computer periodically detects the accelerator pedal state, its temporal change, and the transmission input shaft rotation speed (N _GE ),
Depending on the detected value of the accelerator pedal angle, a suitable coasting speed of the engine (N _FR ) is calculated or read from a table in the computer memory,
When the coast speed (N _FR ) falls below the transmission input shaft speed (N _GE ), the clutch is disengaged, thereby disconnecting the engine from the remaining power train,
When the temporal change in the detected accelerator pedal angle in the closing direction exceeds a predetermined value, a correction amount corresponding to the detected value of the temporal change in the accelerator pedal angle is calculated by the computer, or It is read from another computer memory, and this correction amount is added to the detected transmission input shaft rotation speed (N _GE ) to obtain a corrected transmission input shaft rotation speed (N ′ _GE ).
Then, inertial rotation speed _{(N FR)} is corrected transmission input shaft speed _{(N 'are} compared with _GE), inertial rotation speed _{(N FR)} transmission input shaft speed that is corrected _{(N' GE} ), The clutch is disengaged when falling below. 2. The method according to claim 1, wherein the throttle valve angle and its change with time are detected instead of the accelerator pedal angle. A method for controlling automatic connection of an internal combustion engine to a power train of a vehicle, comprising:
In a method, between the internal combustion engine and the transmission, there is provided a computer-operable clutch, which can be engaged to end the coasting phase of the motor vehicle,
While the car is driving, the computer periodically detects the engine speed (N _M ) and its temporal change,
When the engine speed (N _M ) exceeds the transmission input shaft speed (N _GE ), the clutch is engaged,
When the temporal change in the detected engine speed exceeds a predetermined value, a correction amount depending on the temporal change in the engine speed is calculated by the computer or read from the computer memory, This corrected amount is subsequently subtracted from the detected transmission input shaft speed (N _GE ) to obtain a corrected transmission input shaft speed (N ″ _GE ),
Subsequently, the engine speed (N _M ) and the corrected transmission input shaft speed (N ″ _GE ) are compared with each other,
Method characterized by when the above engine speed (N _M) is corrected transmission input shaft rotational speed (N _"GE), the clutch is linked.

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