JPH0210738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile engine control device,
In particular, the present invention relates to an automobile engine control device suitable for an engine that extracts power through a transmission.

Conventional engine control devices include devices that control engine control parameters according to the gear position of a manual transmission, and devices that control the gear position of an automatic transmission according to changes in engine control parameters ( (Japanese Patent Application Laid-open No. 153832/1983). In the former case, the gear position is selected manually, so the engine cannot be operated in the optimum condition for the vehicle speed and load.
The latter are mechanical parts such as fluid couplings and centrifugal clutches, which affect deceleration (=transmission output shaft rotation speed/engine crankshaft rotation speed) and transmitted torque, so the engine can be operated under optimal conditions. I can't. Both of these have traditionally been treated as different things, with either only the former or only the latter. However, in order to reduce fuel costs when driving a car, it is necessary to have the optimum gear and the optimum amount of fuel for the speed of the car, so it is necessary to control the two in an organic relationship. It is necessary. This means that in the future, if it becomes difficult to use 100% gasoline as a fuel, for example if methanol is used as an ingredient, it will be difficult to organically control both of the above due to issues such as instantaneous power. It becomes important.

In particular, in the case of automatic transmissions that do not have a clutch, smooth acceleration may not be possible depending on the method of reduction ratio control and fuel amount control when the car starts running or accelerates from low speed. First, there is a problem that ride comfort such as the feeling of acceleration deteriorates.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automobile engine control device that enables smooth acceleration operation at startup and at low speeds even in the case of an automatic transmission without a clutch.

In order to achieve the above object, the present invention provides an engine control device including a microcomputer and determining a reduction ratio and a fuel amount of an automatic transmission by the microcomputer. The detected values of the accelerator pedal position and vehicle speed are acquired from the
The reduction ratio is determined by determining the engine torque that is necessary to output the propeller shaft torque determined based on the accelerator pedal position and which minimizes the amount of fuel, and also according to a predetermined function based on the accelerator pedal position and vehicle speed. Therefore, the fuel amount is determined, the value obtained by dividing the fuel amount by a predetermined maximum fuel amount is compared with the reduction ratio, and when the reduction ratio is small, the reduction ratio is corrected to decrease by a certain amount, and the engine Import the detected value of engine speed from the rotation speed detector,
The present invention is characterized in that when the engine speed is smaller than a preset idle speed, the fuel amount is corrected to increase by a certain amount.

Examples of the present invention will be described below.

FIG. 1 shows a control circuit showing one embodiment of an engine control device according to the present invention.

In the figure, an intake pipe 2 of an engine 1 is provided with a throttle valve 4 . This throttle valve 4 is intended to adjust the intake flow rate, and is configured to be driven by a throttle valve operating device 6. A controller 8 is connected to the throttle valve operator 6, and a position detector 9 is connected to the controller 8. The position detector 9 detects the amount of depression of the accelerator pedal 10, that is, the position of the accelerator pedal, and the output signal from the position detector 9, which is output according to the position of the accelerator pedal 10, causes the controller 8 to control the throttle valve. A signal is output to the operating device 6 to drive the throttle valve 4. Further, a fuel adjustment valve 5 is attached to the fuel supply path attached to the engine 1.
This fuel regulating valve 5 is configured to be opened and closed by a regulating valve operator 7. This regulating valve operator 7
A controller 8 is connected to. Further, a transmission 12 is attached to the engine 1,
A crankshaft (not shown) is configured to rotate via this transmission 12. A speed change operating device 11 is attached to this transmission 12, and a controller 8 is connected to this speed change operating device 11.

On the other hand, the controller 8 is configured to receive an output value from an engine rotation speed sensor 13 that detects the engine rotation speed, and an output signal from an atmospheric pressure sensor 17 that detects atmospheric pressure. . The controller 8 is also configured to receive a signal from a position detector 16 that detects the position of the brake pedal 15. Furthermore, an intake air temperature sensor 18 is connected to the controller 8 to detect the temperature of intake air drawn from the intake pipe 2.

Further, a starter 14 is connected to the engine 1, and an exhaust pipe 3 is provided.

In such a configuration, air is supplied to the engine 1 via the throttle valve 4, and fuel is supplied to the engine 1 via the fuel adjustment valve 5. This supply operation is performed as follows depending on whether the engine is a spark ignition engine such as a gasoline engine or a compression ignition engine such as a diesel engine.

() In the case of a spark ignition engine Information on the position of the accelerator pedal 10 is input to the controller 8 via the position detector 9. The detector 9 is a normal potentiometer, which is converted into a digital value by an A/D converter in the controller 8. The position signal of the accelerator pedal 10 converted into a digital value by this A/D converter is input to a microprocessor within the controller 8. This accelerator pedal 10
The amount of fuel supplied to the engine Y is determined by the digital value X at the position. The supplied fuel amount Y is also a digital value. When the fuel is methanol, the calorific value is low, so the correction value K _p of the calorific value is taken into account to calculate Y=K _p f(X). f(X) is an algebraic value, or the fuel amount Y supplied to the engine relative to the value X of the position of the accelerator pedal 10 is stored in advance, and is determined by a correction calculation. The correction value K ₀ for the calorific value is approximately 1.0 for an engine and approximately 2.0 for methanol. The value of this correction value _K0 is also set in advance by the controller 8.
is stored in When the accelerator pedal value X is determined, the amount of fuel Y to be supplied to the engine is determined.

First, when starting the car for the first time, the required torque is obtained by adjusting the reduction ratio α. In general, reduction ratio α
The relationship between engine torque T _e , engine rotational speed N _e , propeller shaft torque T _p , and propeller rotational speed N _p is T _p /T _e = α ... (1) N _p /N _e = 1/ α...(2). Therefore, when the vehicle speed is increased at a constant rate of increase, it is necessary to appropriately change the reduction ratio α to maintain the engine torque T _e and the engine rotational speed N _e in the optimum range. Rotation speed of propell shaft
N _p is input from the rotation speed sensor 13 to the controller 8 . In other words, the value of the accelerator pedal position
The microprocessor in the controller 8 calculates the engine torque T _e and the reduction ratio α from the values of the propeller rotation speed N _p and the propeller rotation speed N p. Further, the amount of fuel supplied to the engine Y is determined from the engine torque T _e .

That is, since the accelerator pedal value X corresponds to the target acceleration value, the required value of the propeller shaft torque T _p is determined by this value. The engine torque Te and rotational speed Ne that satisfy this torque T _p requirement and minimize the amount of fuel are determined, and the transmission is controlled by determining the reduction ratio α that meets these requirements. on the other hand,
In order to output the above-mentioned required engine torque Te, it is necessary to supply fuel in accordance with this. Therefore, the engine torque Te is the propeller rotation speed corresponding to the accelerator pedal value X and the vehicle speed.
Since it is correlated with N _p , the fuel amount Y is determined as a function of X and N _p .

Next, we will explain the relationship between the reduction ratio α and the amount of fuel Y supplied to the engine, dividing it into the cases where the engine starts, when the car starts, when the vehicle is running at a steady state, and when the vehicle decelerates. .

(1) When starting the engine In this case, the reduction ratio α is initially infinite and the propeller rotation speed N _p =0. That is, the second
In the transmission 12 shown in FIG. 1 having the configuration shown in the figure, first, when the input shaft 21 rotates, the cone 22 contacts the ring 23 and rotates. The rotation of the cone body 22 is transmitted to an intermediate shaft 24 directly connected to the cone body 22, and the cone body 25 is rotated by this intermediate shaft 24. Since the conical body 25 rotates along the ring 26, it rotates the rotating body 27, which moves in unison with the intermediate shaft 24. This rotating body 27 is mechanically connected to an output shaft 28. Now, when the ring 23 is moved in the direction shown by arrow A, the intermediate shaft 2
4 rotation speed becomes smaller. This intermediate shaft 24
The change in the ratio of the angular velocity ω ₀ of the input shaft 21 to the angular velocity ω ₁ of the input shaft 21 is shown in FIG. Furthermore, when the ring 23 is moved in the direction of arrow B, the output shaft 2
The angular velocity of 8 increases. Now, when the ring 23 is moved as far as it can go in the direction shown by arrow A, the angular velocity ratio between the input shaft 21 and the intermediate shaft 24 becomes 1.
When the ring 26 is placed at the right end in FIG. 2, the angular velocity of the output shaft 28 is decelerated to zero. In this way, the reduction ratio of the transmission 12 is determined by the positions of the rings 23 and 26. The rings 23, 26 are configured to be moved by motors 29, 30.

Next, when starting the engine 1, first move the ring 26 to the position where the angular velocity of the output shaft 28 is zero.
move. An amount of fuel is given to the engine 1 to maintain idle rotation in this state. The engine temperature is determined by using the starting fuel _Ys as a function of the engine temperature _te , Ys=φ(te), which is given to the microprocessor in advance. Engine 1 was originally
When the engine is driven by the starter 14 and fuel is supplied, its explosive torque balances the idle rotation. On the other hand, the opening degree of the throttle valve 4 is adjusted so that the appropriate amount of intake air is obtained. This is the required air volume Z
Information regarding this is stored in the microprocessor, and the throttle valve operating device 6 is controlled and adjusted using the Z signal. Generally, for the air-fuel ratio R, Z
=R・Y. Ignition timing is also controlled by controller 8.
controlled by the output signal of

(2) When starting the car Next, we will explain the control when starting the car.

When the ring 26 of the transmission 12 shown in FIG. 2 is moved in the direction shown by arrow B, the angular velocity of the output shaft 28 increases from zero. Here, the propeller torque T _p is determined by the value X of the accelerator pedal position. If the engine torque T _e is given so that the engine torque T _e becomes the optimal value (the point that gives the minimum fuel efficiency) for this given propeller torque T _p , the reduction ratio α is determined from the above equation (1). . The ring 26 is moved so as to provide this reduction ratio α. Now, if propeller torque T _p = T _e , reduction ratio α = 1,
That is, propeller rotation speed N _p =engine rotation speed _Ne . However, at startup, propeller rotation speed N _p <engine rotation speed _Ne , so propeller torque T _p > engine torque T _e . Since the engine rotation speed N _e and propeller rotation speed N _p change as shown in Fig. 4,
Immediately after startup, the reduction ratio α is extremely large. Therefore, the engine torque T _e may be reduced. This engine torque T _e changes as shown in FIG. In this way, at startup, the reduction ratio α and the engine torque T _e are provided so that the engine rotational speed N _e decreases and the engine does not stop. In other words, the microprocessor calculates the engine torque T _e and the reduction ratio α according to the given accelerator pedal position value X, and calculates the engine rotation speed N e as shown in FIGS. 4 and 5 _. The supplied fuel amount Y and the reduction ratio α are controlled so that the engine torque T _e is maintained. The reduction ratio α is adjusted by controlling the speed change operation device 11 with the controller 8.

(3) During Steady Driving Next, steady driving, that is, normal driving will be explained.

When the propeller rotation speed N _p reaches a certain value,
No acceleration force is required. Therefore, the propeller torque T _p becomes smaller. In this case, the above (1)
The reduction ratio α in the equation becomes smaller, and the propeller rotation speed
N _p >engine speed N _e . That is,
Reduce the engine speed N _e as much as possible,
Reduce engine friction loss. for example,
In the case of reduction ratio α = 1, engine speed Ne = 3000 rpm, and vehicle speed = 60 km/h shown at point A in Fig. 6, the reduction ratio α = 0.5 and the engine speed N _e = 1500 rpm. If the engine is operated at point B in the diagram, the fuel efficiency will be lower. Such selection of the reduction ratio α and the engine torque T _e is performed by the controller 8.

(4) During deceleration Next, we will explain the deceleration time when the brake etc. are applied to decelerate.

If engine braking is required, an appropriate reduction ratio α is selected. Engine RPM
Within the range where N _e does not exceed 6000 rpm, the reduction ratio α
can be maximized. On the other hand, at this time,
The fuel supply is suddenly cut off, and the throttle valve 4 is in the fully closed position. The position of the accelerator pedal 10 at this time is the Xo position in which the foot is released, and is either idling or decelerating. That is, accelerator pedal 1
When the position of zero is X=X _p and the propeller rotation speed N _p >0, it is deceleration operation. Therefore, X=X _p ,
If N _p > 0, the fuel supply is cut off,
The throttle valve 4 is in a fully closed position. Here, when the engine speed N _e decreases to a certain level, fuel supply is started and the reduction ratio α is increased to maintain the engine at idle operation. Further, when going down a gentle slope, there is no particular need for engine braking, so the reduction ratio α does not need to be large in this case. The position of the brake pedal 15 shown in FIG. 1 is detected by the position detector 1, and the reduction ratio α is set in accordance with this signal.

() In the case of a compression ignition engine In the case of a compression ignition engine such as a diesel engine, the operation of the throttle valve 4 is omitted, and the control of the ignition timing is also omitted. Instead, control of injection timing is added. The amount of fuel to be injected is given in the same manner as in the case of spark ignition engines such as gasoline as described above. However, since the maximum injection amount is limited by the air density, the signals from the atmospheric pressure sensor 17 and intake air temperature sensor 18 shown in Fig. 1 are input to the controller 8 to determine the maximum injection amount in advance, and the injection amount is supplied within this range. Determine the fuel amount Y. Further, since there is normally no throttle valve 4, there is no engine braking effect.

Further, the injection timing is controlled by the controller 8, and an appropriate injection timing is selected according to the engine rotational speed N _e and the supplied fuel amount Y.

() In-cylinder injection spark ignition engine In this case, ignition timing control is added to the injection timing control of the compression ignition engine described above. The ignition timing is appropriately controlled according to the engine rotational speed N _e and the supplied fuel amount Y.

Next, the operation of this embodiment will be explained.

First, the control of the supplied fuel amount Y and the reduction ratio α at the time of starting the engine will be explained using the flowchart shown in FIG.

First, in step 41, the engine water temperature _te is detected, and in step 42, the amount of fuel to be supplied at the time of starting, _Ys , is determined from the formula _Ys = (te ₎ . After determining the supplied fuel amount _Ys in step 42, the starter switch is turned on in step 43, and the reduction ratio α is changed in step 44.
is set to infinity. Next, in step 45, the time Δt for opening the fuel regulating valve 5 in synchronization with the engine speed N _e is determined by Δt=KY _s , and the fuel regulating valve 5 is opened for the time Δt to supply the engine 1 with the starting time. Fuel is supplied according to the fuel amount Y _s . If this fuel is, for example, methanol fuel, the calorific value correction value K _p is corrected in step 46.
The supplied fuel amount Y _s is determined as Y _s = K _p Y _s . In this way, the engine 1 can be started. When the engine 1 starts, it is determined in step 47 whether or not the engine speed N _e is equal to the idle setting speed N _e0 , and when it is determined that the engine speed N _e is equal to the idle setting circuit N _e0 , the control flow is end. If it is determined in this step 47 that the engine rotation speed N _e is not equal to the idle setting rotation speed N _e0 , it is determined in step 48 whether the engine rotation speed N _e is higher than the idle setting rotation speed N _e0 , and it is determined that it is higher. In this case, step 49 is performed by subtracting the predetermined value α from the time Δt.
Return to 47. If it is determined in step 48 that the engine speed N _e is not higher than the set idle speed N _e0 , a predetermined value a is added to the valve opening time Δt of the fuel adjustment 5 in step 50 and the process returns to step 47 . By repeating this process, the engine speed N _e
Match the idle setting rotation speed N _e0 . The supplied fuel amount Y _s corresponding to the valve opening time Δt of the fuel adjustment valve 5 when the engine rotation speed N _e matches the idle set rotation speed N _e0 is determined in advance.

Next, the amount of fuel supplied Y and the reduction ratio α during running and deceleration
The control will be explained using the flowchart shown in FIG.

First, in step 100, it is determined whether the accelerator pedal position is greater than the accelerator pedal position with the foot off. In this step 100, if the accelerator pedal position is greater than the accelerator pedal position with the foot off, that is, if it is determined that the accelerator pedal is being depressed to some extent, this means an acceleration state or a normal driving state. In step 101, the amount of fuel to be supplied Y corresponding to the propeller rotational speed Np taken separately from the accelerator pedal position X is determined by the formula Y=(X, Np). Further, if it is determined in step 100 that the accelerator pedal position X is not greater than the accelerator pedal position _X0 with the foot off, then in step 102 it is determined whether the propeller rotation speed Np is zero. If it is determined in step 102 that the propeller rotation speed Np is zero,
It means the idle operation value and the step
At step 103, the opening time Δt of the fuel adjustment valve 5 is maintained at the previous state, that is, the value corresponding to KY _s . Also, step
If it is determined in step 102 that the propeller rotation speed Np is not equal to zero, it is determined in step 104 whether the engine rotation speed N _e is greater than the idle setting rotation speed N _e0 , and the engine rotation speed N _e is determined as the idle setting. If it is determined that the rotational speed is greater than N _e0 , then in step 105 the opening time Δt of the fuel regulating valve 5 is set to zero, that is, the fuel regulating valve 5 is fully closed.
Furthermore, if it is determined in step 104 that the engine speed N _e is not larger than the idle set speed N _e0 , this means a steady operating value, so the opening time Δt of the fuel adjustment valve 5 is the same as the previous state. Maintain KY _s .

Furthermore, when the amount of fuel to be supplied is calculated in step 101, that is, the accelerator pedal position
The reduction ratio α _p is determined from the ratio of the fuel amount Y determined from the propeller rotation speed Np to the fuel Y that can actually be supplied to satisfy the acceleration. This reduction ratio α _p corresponds to the engine's surplus in terms of fuel amount, and when the current reduction ratio α is smaller than this α _p , it means that there is an excess in the engine torque Te, so the reduction ratio α Change and set a certain amount smaller to accelerate. On the other hand, the fuel amount Y is corrected so that the engine speed Ne does not fall below the idle speed N _e0 due to the increased engine load. As mentioned above, the reduction ratio α in step 111 is determined by the engine torque Te and rotational speed that satisfy the propeller torque Tp corresponding to the accelerator pedal position X and minimize the amount of fuel.
It is determined from Ne. After setting the actually supplied fuel amount Y to the maximum supplied fuel amount Ymax, in step 110, the reduction ratio is calculated from the ratio between the supplied fuel amount Y calculated in step 101 and the supplied fuel amount actually supplied. Find α _p . When the reduction ratio α _p is determined in this step 110, the step
It is determined whether the reduction ratio α _p obtained in step 111 is larger than the current reduction ratio α. This step
If it is determined that the reduction ratio α _p calculated at 110 o'clock is greater than the current reduction ratio α, the process returns to step 101. If it is determined in step 111 that the current reduction ratio α is not smaller than the calculated reduction ratio α _p , then in step 110 a predetermined value b is subtracted from the current reduction ratio α to determine the reduction ratio. When the reduction ratio is determined in step 112, it is determined in step 113 whether the engine rotational speed N _e is greater than the idle set rotational speed N _e0 . If it is determined in this step 113 that the engine rotation speed N _e is larger than the idle set rotation speed N _e0 , then in step 114 the fuel supply amount Y is supplied by subtracting the predetermined amount c from the currently supplied fuel amount. . In addition, if it is determined in step 113 that the engine speed N _e is not larger than the idle set speed N _e0 , the current fuel supply amount Y predetermined amount c
to supply fuel. After any of the operations in steps 114 and 115 are performed,
In step 116, it is determined whether the engine rotation speed N _e is equal to or less than the idle setting rotation speed N _e0 , and if it is determined that they are not equal, the process returns to step 113. Further, if it is determined in step 116 that the engine speed N _e is equal to the idle set speed N _e0 , the control flow is ended.

Therefore, according to this embodiment, an appropriate acceleration force can be smoothly obtained depending on the position of the accelerator pedal 10. Note that in order to increase this effect, means for selecting the reduction ratio α and means for determining the fuel amount in accordance with the position of the accelerator pedal 10 are essential.

As explained above, according to the present invention, not only the accelerator pedal value The clutch is used to calculate the engine torque Te and, in turn, the amount of fuel, and when the engine has extra acceleration power, the reduction ratio is corrected to a smaller value to encourage acceleration, and the amount of fuel is corrected accordingly. Even with a speed reducer that is not equipped with a speed reducer, smooth acceleration operation can be performed at the time of startup, etc.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figure 2 is a circuit diagram showing an embodiment of the present invention.
Figure 1 is a cross-sectional configuration diagram of the transmission of the illustrated embodiment, Figure 3 is a diagram for explaining the operation of the transmission shown in Figure 2, and Figure 4 is a change in engine rotation speed Np with respect to time. Figure 5 shows the engine torque.
Figure 6 is a diagram showing the magnitude of Te with respect to the time axis, Figure 6 is a diagram showing torque versus rotational speed, Figure 7 is a diagram showing the torque characteristics of engine rotational speed and propeller rotational speed over time, and Figure 8 is at engine start. FIG. 9 is a control flowchart of the amount of fuel supplied and the reduction ratio when decelerating the vehicle. DESCRIPTION OF SYMBOLS 1... Engine, 5... Fuel adjustment valve, 8... Controller, 9... Position detector, 10... Accelerator pedal, 12... Transmission, 13... Rotational speed sensor.

Claims (1)

[Claims] 1. In an engine control device that includes a microcomputer and determines the reduction ratio and fuel amount of an automatic transmission by the microcomputer, the accelerator pedal position and vehicle speed are determined from an accelerator pedal position detector and a vehicle speed detector, respectively. A reduction ratio is determined by taking in the detected value and determining the engine torque that is necessary to output the propeller shaft torque determined based on the accelerator pedal position and that requires the minimum amount of fuel, and also determines the reduction ratio in advance based on the accelerator pedal position and vehicle speed. Determine the amount of fuel according to a predetermined function, compare the value obtained by dividing the fuel amount by a predetermined maximum fuel amount and the reduction ratio, and if the reduction ratio is small, reduce the reduction ratio by a certain amount. The fuel amount is corrected, and further the detected value of the engine rotation speed is taken in from an engine rotation speed detector, and when the engine rotation speed is smaller than a preset idle rotation speed, the fuel amount is corrected to increase by a certain amount. Engine control device.