JPH0427421B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) This invention relates to a vehicle drive system for controlling the vehicle drive state determined by engine speed, torque, etc. to a desired state in accordance with the depression operation of the accelerator pedal. This relates to a control device.

(Prior Art) Normally, in a car, contour lines with a constant fuel consumption rate are drawn on a plane showing the driving state of the car, with the horizontal axis showing the engine speed and the vertical axis showing the engine torque as shown in Figure 1a. E ₁ , E ₂ , E ₃ inside
It becomes a curve like this. This is because normal cars use a transmission with a set gear ratio and control the engine output and vehicle speed by changing the opening of the throttle valve, so the throttle valve is placed in a slightly closed position rather than fully open. The engine is set so that the minimum fuel consumption rate is in the region D, and when accelerating, the throttle valve is fully opened and an air-fuel ratio enrichment device is activated so that large torque can be obtained. This is because there was a need to ensure extra torque. When controlling the driving state of a car equipped with such an engine,
The driving condition of the car is as close as possible to the curve in the center of the diagram.
It is desirable to control the drive so that the fuel consumption rate is in or close to the lowest fuel consumption area D within _E1 . Note that A in FIG. 1A is the throttle valve fully open line. As one of the devices for controlling the drive of automobiles so as to obtain good fuel efficiency, conventionally, as shown in Japanese Patent Application Laid-open No. 134162/1983, a device optimized for the above purpose has been developed. The throttle valve opening and gear ratio are determined for each driving state and mapped, and the throttle valve opening and gear ratio are read from the map according to the amount of depression of the accelerator pedal, and the throttle valve is opened and closed. There is one that adjusts the gear ratio of the transmission.

However, in conventional automobile drive control devices, the throttle valve is opened and closed depending on the amount of depression of the accelerator pedal, and the charging efficiency of the combustion chamber is changed to obtain the desired engine output and vehicle speed. In the control method, the intake passage downstream of the throttle valve becomes negative pressure in a region where the throttle valve opening is small, and this becomes an engine load.
A so-called pumping loss of engine output occurs,
There was a problem with worsening fuel efficiency.

(Objective of the Invention) By the way, when we consider the drive control method of an automobile from the engine speed and torque characteristics, we find the following. Here, Fig. 1b is an engine speed/torque characteristic curve diagram of an automobile. In the figure, the solid line A indicates the characteristic when the throttle valve is kept fully open, that is, the fully open line, and the dashed line B indicates the gear ratio. The characteristics when kept constant, that is, the constant gear line,
The two-dot chain line C shows the characteristics when the engine output is kept constant, that is, the constant output line.

In other words, in conventional automobiles, most of the
A transmission with a set gear ratio such as 1st to 5th gear is used, but when the gear ratio of the transmission is constant, the rotation speed/torque characteristics will be as shown by the dashed line B in the diagram. As mentioned above, it was necessary to control the engine output by adjusting the opening degree of the throttle valve. Now, in a certain operating state on this constant gear line B, for example, in operating state B where the engine speed is 3000 rpm and the torque T _{is 1} , the engine output is
80 PS, and if we reduce the engine speed while maintaining this engine output, the torque will increase along the chain double-dashed line C, which is a constant output line, as shown by arrow c in the figure, and the engine speed will increase. When the rotational speed reaches 2000 rpm, the torque is the value T ₂ at the intersection a of this constant output line C and the fully open line A.
become. This means that the engine output that was previously obtained with a constant gear ratio can be obtained with the throttle valve fully open by changing the gear ratio. Therefore, if the gear ratio can be changed continuously using a continuously variable transmission, a completely new control method can be obtained that can control the vehicle to the desired operating state while keeping the throttle valve fully open. becomes. Moreover, with this control method, the engine output and vehicle speed can be secured by changing the gear ratio, so as shown in FIG. This control method also prevents negative pressure in the intake passage downstream of the throttle valve, making it possible to significantly reduce engine output pumping loss.

By the way, as mentioned above, when the throttle valve is kept constant near full open throughout the entire operating range of the engine, it is necessary to reduce the engine speed as much as possible when the required output is low, that is, when the vehicle is running at low speed, and the engine stability is reduced. It has a negative impact on sexuality. Furthermore, a transmission with a very wide range must be used, and in that case, the transmission becomes large and space becomes a problem.

Therefore, this invention focuses on the fact that the engine output, which was conventionally obtained with a constant gear ratio, can be obtained with the throttle fully open by continuously changing the gear ratio, as described above, and uses a completely new control method. It is an object of the present invention to provide a drive control device for an automobile that significantly improves fuel efficiency, does not deteriorate engine stability during low vehicle speed operation, and does not require increasing the size of the transmission.

(Structure of the Invention) That is, the present invention includes a continuously variable transmission interposed between an engine and wheels, an adjusting means for adjusting a gear ratio of the continuously variable transmission, and a driving means for driving a throttle valve. When the accelerator pedal depression amount is within a predetermined range, the driving means maintains the throttle valve at a constant value close to fully open, thereby reducing the pumping loss of the engine output, while adjusting the engine output by adjusting the accelerator depression amount. The main focus is to obtain the desired engine output by adjusting the gear ratio according to The desired engine output can be obtained by adjusting the amount according to the amount of accelerator depression.

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 2 and 3 show a drive control device for an automobile according to an embodiment of the present invention. In the figure, 1 is an engine, a throttle valve 3 is provided in an intake passage 2 of the engine 1, a check valve 4 is provided in the intake passage 2 upstream of the throttle valve 3, and a check valve 4 is provided in the intake passage 2 upstream of the throttle valve 3. A bypass passage 5 is formed by bypassing 4. A supercharger 6 is disposed in the middle of this bypass passage 5, and the driving force of the engine is transmitted to the supercharger 6 via pulleys 7, 8 and a belt 9. An electromagnetic clutch 10 is interposed between the supercharger 6 and the pulley 7 to adjust the magnitude of the driving force transmitted. on the other hand,
The downstream side of the throttle valve 3 of the intake passage 2 is branched into intake passages 2a to 2d for each cylinder, and each intake passage 2a to 2d is provided with a fuel injection valve 11a to 11d.

Further, a continuously variable transmission 14 is connected to the output shaft 12 of the engine 1 via a clutch 14a, and a drive shaft 15 of the continuously variable transmission 14 is connected to drive wheels 17 via a differential gear 16. Further, the continuously variable transmission 14 is provided with a gear ratio adjusting device 18, which is an adjusting means for adjusting the gear ratio.
Here, the continuously variable transmission 14 and the gear ratio adjustment device 1
8 is constructed as shown in FIG. That is, the primary pulley 1 is connected to the input shaft 12 of the engine 1.
9, a secondary pulley 20 is provided on each output shaft 15, and both pulleys 19 and 20 are connected by a V-belt 21. The primary pulley 19 includes a fixed pulley 19a, a movable pulley 19b opposing the fixed pulley 19a, and a movable pulley 19b that can move forward and backward, and the pulley 19.
The primary pulley 19 further includes a planetary gear 19d and a hydraulic clutch 28, which are meshed and interposed between the input shaft 12 and the fixed pulley 19a, and the hydraulic clutch 28 is connected to the shift lever (Fig. When the forward gear L is selected, the planetary gear 19
d to the input shaft 12 side and the fixed pulley 19a
(The primary pulley 19) is rotated in the same direction as the input shaft 12, and in the reverse gear R, the planetary gear 19d is fixed to the casing 14b side, and the fixed pulley 19a is rotated in the opposite direction to the input shaft 12. ing. Also, the above secondary pulley 2
0 also consists of a fixed pulley 20a, a movable pulley 20b facing the fixed pulley 20b that can move forward and backward, and a hydraulic chamber 20c behind the pulley 20b. The hydraulic chambers 19c and 20c of the primary pulley 19 and the secondary pulley 20 are communicated with an oil pump 22 through an oil passage 27 via a regulator valve 23, and a movable pulley 19b of the primary pulley 19 is connected to the oil pump 22 through a regulator valve 23. A secondary pulley 26 is provided to control the supply and discharge of hydraulic pressure to the hydraulic chamber 20c of the secondary pulley 20. By controlling the supply and discharge of hydraulic pressure to each hydraulic chamber 19c, 20c, each pulley 19, Fixed pulleys 19a, 20a and movable pulley 19 in 20
The V-belt 21 is configured to move up and down within the gap as the gap between b and 20b changes, so that the speed ratio can be changed steplessly. Further, a first electromagnetic valve 25 is interposed between the hydraulic chamber 19c of the primary pulley 19 and the regulator valve 23 for controlling the supply of hydraulic pressure to the hydraulic chamber 19c, and the first electromagnetic valve 25 will be described later. When the gear ratio down signal 93 is received, hydraulic pressure is supplied to the hydraulic chamber 19c of the primary pulley 19, and the movable pulley 19b is connected to the fixed pulley 19a.
The hydraulic chamber 20c of the secondary pulley 20 is relieved by controlling the secondary valve 26, and the gap between the fixed pulley 20a and the movable pulley 20b is widened, thereby increasing the gear ratio. It is controlled to make it smaller. Further, between the hydraulic chamber 19c of the primary pulley 19 and the first electromagnetic valve 25, there is a second valve for controlling the discharge of hydraulic pressure from the hydraulic chamber 19c.
A solenoid valve 24 is interposed, and the second solenoid valve 24 opens the primary pulley 19 by receiving a gear ratio up signal 92 (described later) and opening the second solenoid valve 24.
The hydraulic chamber 19c of the movable pulley 1 is relieved.
9b is moved backward relative to the fixed pulley 19a to widen the gap between the two, and as a result, hydraulic pressure is supplied to the hydraulic chamber 20c of the secondary pulley 20 under the control of the secondary valve 26, and the fixed pulley 2
The control is performed so that the gap between Oa and the movable pulley 20b is narrowed, thereby increasing the gear ratio. Further, 13a is a clutch valve for disabling the transmission relationship between the primary pulley 19 and the secondary pulley 20 via the V-belt 21.

Further, in FIG. 2a, 29 is an accelerator position sensor which is an accelerator detection means for detecting the amount of depression of the accelerator pedal 30, and in this embodiment, the amount of depression of the accelerator pedal 30 is regarded as a parameter indicating the request for engine output. ing. 31 is a brake position sensor that detects the amount of depression of the brake pedal 32; 33 is an engine speed sensor that detects the engine speed; 34 is an air flow meter that detects the amount of intake air; 35 is a sensor that detects the opening degree of the throttle valve 3. 36 is a throttle actuator which is a driving means for opening and closing the throttle valve 3; and 37 is a pressure sensor for detecting the pressure in the intake passage 2.

Furthermore, 38 is an input/output interface 39,
The control circuit is a control means composed of a CPU 40 and a memory 41, and the memory 41 stores an arithmetic processing program, a map of the first and second target rotation speeds, a map of the target throttle valve opening, etc. Stored. And the first of the above maps
The target rotational speed is a value as shown in FIG. 4, that is, a constant value Nel when the amount of depression of the accelerator pedal 30 is less than the first set value α ₁ , and a constant value Nem when the amount of depression of the accelerator pedal 30 is equal to or more than the second set value α ₂ . , and when the first set value α is greater than or equal to ₁ and the second set value α is less than or equal to ₂ , the value increases almost linearly as the amount of accelerator depression increases, and the target throttle valve opening As shown in FIG. 5, when the amount of depression of the accelerator pedal 30 is less than the first set value _α1 , the degree increases linearly with the increase of the amount of accelerator depression α, and the first set value α When it is ₁ or more, the value is a constant value θ ₁ . The CPU 40 then controls each of the sensors 29, 31, 33,
34, 35, and 37, the gear ratio adjusting device 18, throttle actuator 36,
The fuel injection amount and supercharger 6 are controlled to adjust the gear ratio, throttle opening, fuel injection amount, and supercharging amount. That is, when the amount of depression of the accelerator pedal 30 is less than the first set value _α1 , the engine speed is adjusted to a constant value.
Nel and the throttle valve opening is set to a value corresponding to the accelerator depression amount (X in the figure), or when the above depression amount is greater than the first set value α ₁ and less than the second set value α ₂ , the throttle valve is The opening degree is set to a constant value θ ₁ , and the engine speed is set to a value corresponding to the amount of accelerator depression (Y in the figure).
), and when the above-mentioned depression amount is equal to or greater than the second set value α ₂ , both the engine speed and the throttle valve opening are set to a constant value Nem, θ ₁ (part Z in the figure),
Control. Furthermore, when the amount of depression of the brake pedal 32 is equal to or greater than the set value β, the CPU 40 reduces the opening of the throttle valve and controls the engine speed to a value corresponding to the amount of depression of the brake pedal. When the depression amount of 30 is less than the second set value α ₂ , a basic fuel injection pulse is generated according to the engine speed and the intake air amount so that the air-fuel ratio of the mixture becomes the stoichiometric air-fuel ratio λ = 1, When the second set value α ₂ or higher, the fuel injection amount is controlled by correcting the basic fuel injection pulse so that the air-fuel ratio of the air-fuel mixture becomes rich, for example, 13.5. More CPU
Reference numeral 40 refers to the control of the electromagnetic clutch 10, and starts supercharging when the amount of depression of the accelerator pedal 30 reaches the second depression amount α ₂ or more, and applies engine driving force to the supercharger 6 in accordance with the amount of depression of the accelerator pedal 30. The electromagnetic clutch 10 is controlled so that the transmission is transmitted.

In addition, FIG. 2b shows the CPU 4 of the control circuit 38.
4 is a diagram showing the components of 0 divided into functional blocks. In the diagram, M10 receives a signal from the accelerator position sensor 29, and receives the engine rotation which indicates the amount of accelerator depression and the rotation speed of the drive system shown in FIG. Based on a predetermined relationship with the number, when the accelerator depression amount is above a predetermined value, the engine rotation speed is set according to the accelerator depression amount, and when the accelerator depression amount is below a predetermined value, the engine rotation speed is constant regardless of the accelerator depression amount. Drive system target rotation speed setting means for setting the rotation speed (target rotation speed of the drive system), M11 is the output of the drive system target rotation speed setting means and the engine rotation speed sensor 33
M12 is an accelerator position control means that compares the engine rotation speed, which is the actual drive system rotation speed, and controls the speed ratio adjustment means 18 so that the actual engine rotation speed becomes the target engine rotation speed. After receiving the signal from the sensor 29, as shown in FIG.
M13 is the above-mentioned target throttle valve opening setting means for setting the target throttle valve opening based on the relationship that when the accelerator depression is below a predetermined value, the throttle valve opening increases in accordance with the accelerator depression, and becomes constant above the predetermined value. The output of the target throttle valve opening setting means is compared with the actual throttle valve opening of the throttle position sensor 35, and the throttle actuator 36 is operated so that the actual throttle valve opening becomes the target throttle valve opening. This is a throttle valve opening control means that controls the opening of the throttle valve.

Further, FIG. 7 is a diagram for explaining the arithmetic processing of the CPU 40, and this is a diagram for explaining the arithmetic processing of the CPU 40.
This is a hardware circuit diagram showing the calculation process.
In the figure, 42 is the accelerator position sensor 2
9 is an accelerator depression amount signal which is a detection signal, 43 is a brake depression amount signal which is a detection signal of the brake position sensor 31, 44 and 45 are engine rotation speed signals which are detection signals of the engine rotation speed sensor 33, and 46 is a throttle A throttle valve opening signal 47 is a detection signal of the throttle position sensor 35, and an intake pipe pressure signal 47 is a detection signal of the pressure sensor 37.

In addition, in Fig. 7, characteristic curves 48 to 51 having an x-axis and a y-axis drawn within a square frame output the y-axis on the above-mentioned characteristic curve when the input to the circuit is an x value. This is a means of generating a function. In reality, this input (x value) is input into a predetermined memory map in the CPU 40 and the output (y value) is obtained by reading the stored value from the map. can be thought of as a function generator that generates an output (y value) in response to an input (x value) in terms of hardware, so this is shown in the figure. And specifically, 48
is the fourth signal for the signal 42 indicating the accelerator depression amount α.
49 is a target throttle valve opening generating means that generates the target throttle valve opening shown in FIG. 5 in response to the accelerator depression amount signal 42; 50 is a target intake pipe pressure generating means for generating a target intake pipe pressure in response to the accelerator depression amount signal 42, and 51 is a second target for generating a second target rotation speed in response to the signal 43 indicating the brake depression amount β. It is a rotation speed generating means.

Further, in the figure, 52 to 64 are determination means for determining whether the input is greater than or equal to the set value, or less than or equal to the set value, and these determine "1" when the input value falls within the shaded area. It is now output. 65-68 are adders and subtracters that add and subtract two inputs, 69-79 are AND gates, 80-
85 is an OR gate. Further, 86 to 93 are the above AND gates 69 to 79 or OR gates 80
- These are various control signals obtained when the signal from 85 is "1", and 86 is an air-fuel ratio enrichment signal for enriching the air-fuel ratio of the air-fuel mixture. When this signal is output, basic fuel injection is performed. The pulse is corrected so that the A/F is on the rich side.
Reference numeral 87 is a stoichiometric air-fuel ratio signal for bringing the air-fuel mixture to the stoichiometric air-fuel ratio, and when this signal is output, the basic fuel injection pulse is used as it is as the injection pulse. Further, 88 is a supercharging up signal for increasing the supercharging amount, 89 is a supercharging down signal for decreasing the supercharging amount, 90 is an opening up signal for increasing the opening of the throttle valve 3, and 91 92 is a gear ratio up signal for increasing the gear ratio of the transmission 14, and 93 is a gear ratio down signal for decreasing the gear ratio.

Next, the general operation of this device will be explained using FIGS. 2 and 6.

When the engine 1 is operated, the continuously variable transmission 14 changes the engine output according to its gear ratio, and transmits it to the drive wheels 1 through the differential gear 16.
7. On the other hand, the accelerator position sensor 29 measures the amount of depression of the accelerator pedal 30, the brake position sensor 31 measures the amount of depression of the brake pedal 32, the engine speed sensor 33 measures the engine speed, and the air flow meter 34 measures the amount of intake air.
The pressure sensors 37 detect intake pipe pressures, and the CPU 40 in the control device 38 receives detection signals from the sensors 29 to 37 and executes predetermined calculation processing. Now, at low rotation and low load, when the amount of depression of the accelerator pedal 30 is smaller than the first set value α ₁ ,
As shown by the straight line of the It controls the gear ratio adjusting device 18 and the throttle actuator 36, and at the same time controls the injection amount from the fuel injection valves 11a to 11d so that the air-fuel ratio of the air-fuel mixture becomes the stoichiometric air-fuel ratio, and as a result, the throttle valve opens. By increasing or decreasing only the degree, the desired engine output can be secured.

Next, the state shifts from the low speed state to the steady state, and the amount of depression of the accelerator pedal 30 reaches the first set value α ₁
If the second setting value α is in the range of ₂ or less, the above
As shown by the substantially straight line in the Y part of FIG. 6, the CPU 40 controls the speed ratio adjusting device 18 and By controlling the throttle actuator 36 and controlling the air-fuel mixture to the stoichiometric air-fuel ratio, the desired engine output is ensured by increasing or decreasing only the engine speed.

Further, when the vehicle is in a high rotation and high load state such as during high speed or acceleration, and the amount of depression of the accelerator pedal 30 becomes larger than the second set value α ₂ , the CPU 40
As shown in the Z part of Fig. 6, both the engine speed and the throttle valve opening are constant values Nem,
The gear ratio adjusting device 18 and the throttle actuator 36 are controlled so that the air-fuel ratio becomes θ ₁ , and at the same time, the fuel injection amount is controlled so that the air-fuel ratio of the air-fuel mixture becomes rich, and the electromagnetic clutch 10 is operated. The amount of supercharging of the supercharger 6 is controlled in accordance with the amount of accelerator depression, and as a result, the air-fuel ratio is made rich, and
By performing supercharging, the torque of the engine increases, and an engine output greater than the maximum output without supercharging is ensured.

Furthermore, when the brake pedal 32 is depressed to perform braking, the CPU 40 controls the throttle actuator 36 so that the throttle valve opening degree becomes small, and the engine rotational speed becomes the rotational speed corresponding to the brake depression amount β. As a result, in addition to braking by the normal braking mechanism,
An engine brake of a magnitude corresponding to the brake depression amount β is applied, and the automobile is quickly decelerated.

Next, the operation will be explained in detail using FIG. 7.

When the accelerator pedal 30 is depressed, the brake pedal 32 is usually not depressed, and the output of the determining means 53 is "1".
Since AND gates 71 to 78 are all open and the engine speed Ne is higher than the minimum speed,
The output of the determining means 56 becomes "1" and the AND gate 82 is opened. In such a state, if the amount of depression of the accelerator pedal 30 is less than or equal to the first set value _α1 , the first target rotation speed generating means 48 first generates a constant target rotation speed Nel, and the adder 66 generates a constant target rotation speed Nel. The difference between this first target rotation speed Nel and the actual engine rotation speed Ne is determined, and when the actual rotation speed is smaller than the first target value Nel, the output of the determination means 59 becomes "1", and the signal is AND gate 71
and transmission ratio up signal 92 via OR gate 84
As a result, the gear ratio of the transmission 14 increases and the actual engine speed also increases. Conversely, when the actual rotational speed Ne is larger than the first target value Nel, the output of the determining means 60 becomes "1",
The signal "1" passes through the AND gate 72 and the OR gate 85 and becomes a gear ratio down signal 93, whereby the gear ratio of the transmission 14 becomes smaller and the actual engine speed also decreases. When the actual engine speed Ne reaches the target speed Nel, the signals of the determining means 59 and 60 both become "0", so the gear ratio is not increased or decreased, and the engine speed is set to the target value. Retained by Nel.

At the same time, the target throttle valve opening generating means 49
Then, the target throttle valve opening according to the accelerator depression amount α is outputted from the accelerator depression amount signal 42, and the difference between the target throttle valve opening and the actual throttle valve opening θ is determined by the adder 67, and the actual throttle valve opening is determined by the adder 67. When the degree θ is smaller than the target value, the output of the determining means 61 becomes "1", and the signal is transmitted to the AND gate 73 and
The opening up signal 90 is generated through the OR gate 82, thereby increasing the throttle valve opening. Conversely, when the actual throttle valve opening θ is larger than the target value, the output of the determining means 62 becomes "1", and the signal "1" passes through the AND gate 74, OR gate 83, and AND gate 79 to reduce the opening. The signal becomes 91, and the throttle valve opening is thereby reduced. And the actual throttle valve opening θ
When the opening reaches the target opening, the signals from the determining means 61 and 62 both become "0", so the opening is not increased or decreased, and the throttle valve 3 is controlled to the opening according to the accelerator depression amount α. be done.

Further, the output of the determining means 54 is the accelerator depression amount α
is less than the second set value α ₂ , so it remains “0” and its inverted signal “1” is sent to the AND gate 7.
8 and the stoichiometric air-fuel ratio signal 8 via the OR gate 80
7, so that the basic fuel injection pulse corresponding to the engine speed and intake air amount is directly applied to the fuel injection valves 11a to 11d, and the air-fuel mixture is controlled to the stoichiometric air-fuel ratio λ=1. Further, the target intake pipe pressure generating means 50 generates an intake pipe pressure according to the accelerator depression amount α, but when the accelerator depression amount α is less than the second set value _α2 , the target intake pipe pressure is equal to the current intake pipe pressure. B, therefore, the supercharging down signal 89 will not be output and the supercharger 6 will not operate.

Next, when the accelerator depression amount changes from the above-mentioned state below the first setting value α ₁ to the range of the first setting value α ₁ or more and the second setting value α ₂ or less, the first target rotation The number generating means 48 now calculates the accelerator depression amount α
On the other hand, the target throttle valve opening generating means 49 generates a constant value θ ₁ near the fully open position.
is generated, and the gear ratio adjusting device 18 and the throttle actuator 36 operate in the same manner as described above so that the actual engine speed becomes the target speed corresponding to the amount of accelerator depression, and the throttle valve opening is set to a constant value near full open. It is controlled so that θ ₁ . Further, at this time, the air-fuel ratio of the air-fuel mixture is controlled to the stoichiometric air-fuel ratio, and supercharging is not performed.

Further, when the amount of depression of the accelerator pedal 30 changes from the above-mentioned second set value α ₂ or less to the second set value α ₂ or more, the first target rotation speed generating means 48 changes the constant target rotation speed Nem to On the other hand, the target throttle valve opening generating means 49 generates a constant value θ ₁ near the above-mentioned full opening, and the gear ratio adjusting device 18 and the throttle actuator 36 operate in the same manner as described above in this case, so that the actual engine speed is Constant target rotation speed
Nem, and the throttle valve opening is the target value θ ₁
It is controlled so that In a region where the accelerator depression amount is equal to or greater than the second set value α ₂ , the target intake pipe pressure generating means 50 generates a target intake pipe pressure according to the accelerator depression amount α, and the adder 68 generates the target intake pipe pressure. The difference between this and the actual intake pipe pressure B is determined. Since the actual intake pipe pressure B is smaller than the target value at the beginning of this region, the determination means 63 first outputs a signal "1", and the signal "1" passes through the AND gate 75 to increase the supercharging. The signal 88 controls the electromagnetic clutch 10 to start supercharging and increase the engine driving force transmitted to the supercharger 6. When this actual intake pipe pressure B becomes larger than the target value, the output of the determination means 64 becomes "1", and the signal "1" passes through the AND gate 76 and the OR gate 81 and becomes the supercharging down signal 89. As a result, the electromagnetic clutch 10 is controlled to reduce the engine driving force transmitted to the supercharger 6. When the actual intake pipe pressure B reaches the target value corresponding to the accelerator depression amount α, the output of the adder 86 becomes zero, so supercharging is not increased or supercharged down, and the supercharging amount is equal to the accelerator depression amount. It is maintained at an amount corresponding to α. At the same time, since the accelerator depression amount α is greater than or equal to the second set value α ₂ , the output of the determining means 54 becomes “1”.
The signal "1" passes through the AND gate 77 and becomes the air-fuel ratio enrichment signal 86, whereby the basic fuel injection pulse read out according to the engine speed and intake air amount is corrected, and the fuel injection valves 11a to 11a.
11d, the air-fuel ratio of the air-fuel mixture is richly controlled.

Further, when the accelerator pedal 30 is depressed as described above, when the foot is removed from the accelerator pedal 30 and the brake pedal 32 is depressed, the signal of the determining means 53 becomes "0", and the AND gate 7
1 to 78 are all closed, and at the same time, the signal of the determining means 52 becomes "1", which opens the AND gates 69 and 70, and the signal of the determining means 52, which is "1", passes through the OR gate 80 and becomes the stoichiometric air-fuel ratio. The signal becomes 87, and the supercharging down signal 89 passes through the OR gate 81.
Then, OR gate 83 and AND gate 7
9, an opening down signal 91 is generated, whereby the air-fuel mixture is controlled to the stoichiometric air-fuel ratio, supercharging is stopped, and the throttle valve 3 is closed. Then, the second target rotation speed generating means 51 generates a second target rotation speed according to the brake depression amount β, and the adder 65 calculates the difference between the second target rotation speed and the actual rotation speed Ne. and the actual rotation speed Ne
When is smaller than the target value, the signal of the determining means 57 becomes "1", and the signal "1" is sent to the AND gate 69.
and transmission ratio up signal 92 via OR gate 84
Therefore, the gear ratio is increased and the actual engine speed increases. Conversely, when the actual rotational speed Ne is larger, the signal of the determining means 58 becomes "1", and this signal "1" is applied to the AND gate 70 and the OR
Since the gear ratio down signal 93 is generated through the gate 85, the gear ratio becomes smaller and the actual engine speed also decreases. When the actual engine speed Ne reaches the second target speed, the output of the adder 65 becomes zero, so the gear ratio is controlled to that value.
The engine rotational speed is maintained at a rotational speed corresponding to the brake depression amount β.

The apparatus of this embodiment as described above can provide the following effects.

() During steady operation, the throttle valve is held at a constant value close to fully open, and the desired engine output is obtained by changing the engine speed.
There is no negative pressure in the intake passage downstream of the throttle valve, and no pumping loss of engine output occurs, resulting in a significant improvement in fuel efficiency.

() As mentioned above, only the engine speed is controlled during steady operation, so the control is more efficient than the conventional case where both the engine speed and torque are controlled by adjusting the throttle valve opening. It's easy.

() Since the air-fuel mixture is controlled to the stoichiometric air-fuel ratio during steady operation, it is possible to drive with low fuel consumption, which also improves fuel efficiency.

() At low engine speeds, in order to obtain low engine output while keeping the throttle valve opening constant, the transmission gear needs to have a large diameter, so it is necessary to open and close the throttle valve. In this case, if the throttle valve is closed over a wide area, fuel efficiency will deteriorate due to engine output pumping loss. In contrast, this device maintains the engine speed at the lowest stable limit at low speeds and low loads, and adjusts the throttle valve opening to obtain the desired engine output, thereby narrowing the range in which the throttle valve is closed. This can reduce deterioration in fuel consumption and does not impair the stability of the engine.

() Furthermore, as described above, since the desired engine output is obtained by opening and closing the throttle valve at low rotation speeds, there is no need to make the gears of the transmission large in diameter, resulting in a compact design.

() At high speeds and high loads, in order to obtain the engine output necessary for high speed operation and acceleration while keeping the throttle valve opening constant, the engine speed must be extremely high. may be damaged. In contrast, this device performs supercharging and makes the air-fuel ratio of the mixture rich, making it possible to obtain sufficient high-speed vehicle operation and acceleration performance without unnecessarily increasing the engine speed. Damage to the engine can be reliably prevented, and engine reliability and good durability can be guaranteed.

() During control, the throttle valve is closed and the engine speed is controlled to a speed corresponding to the amount of brake depression, so engine braking can be applied at the optimal strength depending on the amount of brake depression.

By the way, in the above embodiment, the accelerator depression amount was used as a parameter of the required engine output, but this accelerator depression amount can also be seen as a parameter of the required vehicle speed, and FIG. Another example will be shown. In the figure, the same reference numerals as in FIG. 7 indicate the same or corresponding parts as in FIG.
9) is the actual vehicle speed signal which is the detection signal, and 95 is the accelerator depression amount signal 4 which is the parameter of the requested vehicle speed.
an adder 96 for calculating the difference between 2 and the actual vehicle speed signal 94;
97 is an integrator that integrates the output of the adder 95 and calculates the engine output according to the required vehicle speed; 97 is the adder 95;
98 is an addition unit that adds the integral value of the integrator 96 and the output value of the engine output generating means 97. It is a vessel.

In the device of this embodiment, the accelerator depression amount α is set as the required vehicle speed, and the engine output request Pd is calculated from the difference between this accelerator depression amount α and the actual vehicle speed Vc. The same control is performed. Since the circuit that calculates the engine output request from the required vehicle speed includes an integral element, feedback is applied so that the difference between the accelerator depression amount α and the actual vehicle speed Vc is always zero, and in steady state the difference between the two is zero. As a result, the engine output is equal to the required Pd
It is designed to match the running load of the vehicle.

In the above embodiment, the air-fuel ratio of the air-fuel mixture during steady state was set to the stoichiometric air-fuel ratio, but it may be leaner than this.

Further, in the above embodiment, supercharging is performed at high speeds and high loads, but this supercharging may not be performed. Further, although the air-fuel ratio of the air-fuel mixture at high speed and high load is set to be rich, it may remain at the stoichiometric air-fuel ratio.

(Effects of the Invention) As described above, the present invention focuses on the fact that the engine output, which was conventionally obtained with a constant gear ratio, can be obtained with the throttle valve fully open by continuously changing the gear ratio. When the amount of accelerator pedal depression is within a predetermined range, the pumping loss of engine output is reduced by keeping the throttle valve at a constant value close to fully open, and the desired engine output is achieved by adjusting the gear ratio according to the amount of accelerator depression. As a result, fuel efficiency can be greatly improved, the engine can be operated at optimum fuel efficiency, and the control method is completely new and extremely simple. Furthermore, when the amount of accelerator depression is below a predetermined range, the desired engine output is obtained by controlling the gear ratio and throttle valve according to the amount of accelerator depression while keeping the engine speed constant. This has the effect of reducing the deterioration in fuel efficiency caused by opening and closing the throttle valve by reducing the area in which the valve is closed.

[Brief explanation of drawings]

Figure 1a is a diagram showing the constant fuel consumption rate region on the engine speed/torque curve plane of an automobile.
Figure b is a diagram of engine speed/torque characteristics for explaining the principle of the present invention, Figure 1c is a diagram showing a constant fuel consumption rate region on the engine speed/torque curve plane of the present invention, and Figure 2 is a diagram showing the constant fuel consumption rate region on the engine speed/torque curve plane of the present invention. A configuration diagram of an automobile drive control device according to an embodiment of the present invention, FIG. 3 is a configuration diagram of a continuously variable transmission used in the above device, and FIGS. 4 and 5 are diagrams showing the configuration of a continuously variable transmission used in the device. FIG. 6 is a diagram for explaining the operation of the above device, and FIG. 7 is a diagram for explaining the arithmetic processing of the CPU 40 of the above device. 8 are diagrams for explaining the arithmetic processing of the CPU in another embodiment of the present invention. 1...Engine, 3...Throttle valve, 14...
... Continuously variable transmission, 18 ... Speed ratio adjustment device (adjustment means), 29 ... Accelerator position sensor (accelerator detection means), 36 ... Throttle actuator (driving means), 38 ... Control circuit ( control means).

Claims (1)

[Scope of Claims] 1. A continuously variable transmission interposed between an engine and wheels, an adjusting means for adjusting a gear ratio of the continuously variable transmission, and a means for driving a throttle valve of the engine. the accelerator detection means for detecting the amount of depression of the accelerator pedal; the drive system rotation speed detection means for detecting the rotation speed of the drive system; and the throttle detection means for detecting the throttle valve opening; Based on the relationship that upon receiving a signal from the accelerator detection means, when the amount of accelerator depression is less than or equal to a set value, the engine rotation speed is set to a constant value, and when the amount of accelerator depression is equal to or greater than the set value, the engine rotation speed is determined according to the amount of accelerator depression. drive system target rotation speed setting means for setting a target rotation speed of the drive system; comparing the output of the drive system target rotation speed setting means with the actual drive system rotation speed from the drive system rotation speed detection means; a gear ratio control means for controlling the adjustment means so that the actual rotation speed of the drive system becomes the target rotation speed; and receiving a signal from the accelerator detection means, when the accelerator operation amount is equal to or less than the set value; The goal is to set the throttle valve opening according to the amount of accelerator depression, and to set the target throttle valve opening based on the relationship that when the accelerator depression is equal to or greater than the set value, the throttle valve is close to fully open regardless of the amount of accelerator depression. The throttle valve opening setting means compares the output of the target throttle valve opening setting means with the actual throttle valve opening from the throttle detection means so that the actual throttle valve opening becomes the target throttle valve opening. A drive control device for an automobile, characterized in that a throttle valve opening control means for controlling the drive means is provided.