JPH0428943B2 - - 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 where the fuel consumption rate is constant are drawn on a plane showing the driving state of the car, with engine speed on the horizontal axis and engine torque on the vertical axis, as shown in Figure 1. The curves are E ₁ , E ₂ , and E ₃ , so when controlling the driving state of the vehicle, it is necessary to keep the driving state of the vehicle as far as possible within the region of the lowest fuel consumption rate within the curve E ₁ in the center of the figure. D
It is desirable to control the drive so that it is at or close to the range. Note that A in FIG. 1 is the throttle valve fully open line. As one of the devices that controls the drive of automobiles so as to obtain good fuel efficiency, there has been a
As shown in Publication No. 53-134162, the optimal throttle valve opening and gear ratio for the above purpose are determined in advance for each operating state and mapped out.
Some systems read out the throttle valve opening and gear ratio from the map in accordance with the amount of operation of the accelerator pedal, open and close the throttle valve, and adjust the gear ratio of the transmission.

By the way, in the past, if the catalyst for exhaust purification in a car becomes abnormally high temperature for some reason while the car is running, there is a risk that the catalyst will deteriorate or be damaged, so the air-fuel ratio of the mixer should be adjusted. In addition to reducing the combustion temperature of the air-fuel mixture by enriching the fuel, the system also stops the supply of secondary air to the engine's exhaust system to lower the exhaust temperature, thereby lowering the catalyst temperature and preventing catalyst deterioration and damage. I'm trying to prevent it. However, conventional automobile drive control devices simply enrich the mixture and
Since only the supply of air was stopped, there was a problem in that as the air-fuel mixture became richer, the engine torque suddenly increased, causing a torque shock and causing discomfort to the occupants.

(Object of the Invention) The present invention provides a drive control device for an automobile that independently controls the gear ratio and throttle valve opening according to the amount of accelerator operation to drive the automobile. It is an object of the present invention to provide a drive control device for an automobile that is capable of lowering the catalyst temperature without causing a torque shock in the engine when the engine becomes hot.

(Structure of the invention) Generally, the engine output is Pd, and the engine torque is
When Te is the engine speed and Ne is the engine speed, the engine output is expressed as Pd∝Te×Ne. This formula means that the desired engine output can be obtained by mutually controlling the gear ratio and throttle valve opening. Therefore, by using a continuously variable transmission, If these can be changed independently, even if the air-fuel mixture becomes rich, the engine output can be maintained at a desired value by adjusting both the gear ratio and the throttle valve opening.

Therefore, this invention provides a continuously variable transmission between the engine and the wheels, an adjusting means for adjusting the gear ratio, a driving means for driving the throttle valve, and an accelerator operation amount. A control means is provided which can independently control the adjustment means and the drive means so that an engine output corresponding to the accelerator operation is obtained, and when the catalyst becomes abnormally high temperature, the control means adjusts the engine output to correspond to the accelerator operation amount. The air-fuel ratio of the air-fuel mixture is enriched while maintaining the same value, and the supply of secondary air is stopped.

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

FIG. 2 shows the engine characteristics used in the present invention. In this engine, the region D of the lowest fuel consumption rate is set to be near the throttle valve fully open line A, and these engine characteristics are shown in FIG. 1. The reason why the characteristics are different from those used in the conventional drive control means shown in FIG. In other words, in the conventional device, the engine output and vehicle speed are controlled by changing the throttle valve opening, so it is set so that the minimum fuel consumption rate area D is at a position where the throttle valve is slightly closed rather than fully open. However, when accelerating, etc., it was necessary to fully open the throttle valve and operate an air-fuel ratio enrichment device to obtain large torque, that is, to secure surplus torque. This is because this device can ensure engine output and vehicle speed by changing both the gear ratio and the throttle valve opening.

Further, FIGS. 3 and 4 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 the check valve 4 is bypassed. A bypass passage 5 is formed. A supercharger 6, which is an increasing means for increasing the torque of the engine, is disposed in the middle of the bypass passage 5, and the driving force of the engine is connected 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 to be 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,
Fuel injection valves 11a to 11a are provided in each of the intake passages 2a to 2d.
11d is provided.

On the other hand, the exhaust passage 97 of the engine 1 has a third
As shown in FIG. b, an oxidation catalyst 98 is interposed, and the catalyst 98 is provided with a catalyst temperature sensor 99 serving as catalyst temperature detection means for detecting the temperature of the catalyst.
Further, the exhaust passage 97 is supplied with secondary air.
A secondary air supply means 100 is provided, and the secondary air supply passage 1 is provided in the secondary air supply means 100.
01 is connected to an air cleaner (not shown), and its downstream end is connected to the upstream side of the catalyst 98 in the exhaust passage 97. This secondary air supply passage 101
An air pump 102 is provided in the middle, and a bypass passage 103 is formed by bypassing the air pump 102, and a relief valve 104 is interposed in the bypass passage 103. Further, a secondary air cut valve 105 is provided near the downstream end of the secondary air supply passage 101.

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,
A primary pulley 19 is attached to the input shaft 12 of the engine 1, and a secondary pulley 20 is attached to the output shaft 15.
are respectively provided, 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 facing the fixed pulley 19a, and a movable pulley 19b that can move forward and backward, and the pulley 1
9b, and a hydraulic chamber 19c behind the primary 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. When the forward gear L is selected, the planetary gear 1 is
9d 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. In addition, the above Cancedary 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 valve 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 into 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 for controlling the supply of hydraulic pressure to the hydraulic chamber 19c is interposed between the hydraulic chamber 19c and the regulator valve 23 of the primary pulley 19, 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 is opened in response to a gear ratio up signal 92 (to be described later) to relieve the hydraulic chamber 19c of the primary pulley 19, and the movable pulley 19
b is moved backward relative to the fixed pulley 19a to widen the gap between them, and as a result, hydraulic pressure is supplied to the hydraulic chamber 20c of the secondary pulley 20 by controlling the secondary valve 26, and the fixed pulley 20
The gap between the movable pulley a and the movable pulley 20b is narrowed, and the gear ratio is controlled to be increased. 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.

Also, in Fig. 3a, 29 is the accelerator pedal 30.
An accelerator position sensor 31 is an accelerator detection means for detecting the amount of operation of the brake pedal 3.
2, a brake position sensor that detects the amount of depression; 33, an engine rotation speed sensor that detects the engine rotation speed; 34, an air flow meter that detects the amount of intake air; 35, a torque sensor that detects engine torque; and 36, a throttle. A throttle actuator, which is a driving means for opening and closing the valve 3;
37 is a load sensor that detects the engine load from the throttle valve opening.

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 arithmetic processing programs, maps of first and second target rotation speeds, and the like. The first target rotation speed in the above map is a value as shown in FIG.
is a constant value Nel when it is less than the set value α1, and is a constant value Nem when it is more than the second set value α2, and when it is less than the first set value α1 and less than the second set value α2, the accelerator operation amount is increased. The value increases linearly. Then, the CPU 40 receives the detection signals from the sensors 29, 31, 33, 34, and 35 and performs predetermined arithmetic processing so that the engine speed/torque characteristics shown by the solid line in FIG. 5b are obtained. The gear ratio adjusting device 18, throttle actuator 36, 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 set to a constant value Nel, and the throttle valve opening is set so that the engine torque becomes a value corresponding to the amount of accelerator operation (Fig. When the above-mentioned manipulated variable is greater than or equal to the first set value α1 and less than the second set value α2, the throttle valve opening is adjusted so that the engine torque becomes a constant value Te1, and the engine speed is accelerated. (portion Y in the diagram), and when the above operation amount is equal to or higher than the second set value α2, the engine rotation speed is set to a constant value Nem, and the throttle valve opening is set to a value corresponding to the accelerator operation amount. (Z part in the figure).
Furthermore, when the amount of depression of the brake pedal 32 is equal to or greater than a set value, 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 operating speed of the brake pedal 32 is below the set value and when the amount of depression of the brake pedal 32 is above the set value, the engine speed and intake air amount are adjusted so that the air-fuel ratio of the mixture becomes the stoichiometric air-fuel ratio λ = 1. The fuel injection is performed by correcting the basic fuel injection pulse so that the air-fuel ratio of the air-fuel mixture becomes rich, for example, 13.5 when the accelerator operating speed accelerates to or above the set value. Control the amount. Furthermore, regarding the control of the electromagnetic clutch 10, the CPU 40 starts supercharging when the operating amount of the accelerator pedal 30 exceeds the second set value α2, and the engine driving force corresponding to the accelerator depression amount is applied to the supercharger 6. The electromagnetic clutch 10 is controlled so that the signal is transmitted to the electromagnetic clutch 10.

Further, the CPU 40 receives signals from the engine speed sensor 33, load sensor 37, and catalyst temperature sensor 99, and when the catalyst temperature is below a set value, fully opens the secondary air cut valve 105, and also changes the engine speed and load. The supply amount of secondary air is controlled by adjusting the opening degree of the relief valve 104 according to the temperature, and when the catalyst temperature exceeds the set value, the fuel injection amount is adjusted so that the air-fuel ratio of the mixture becomes rich. control and at the same time relief valve 10
4 fully open and open the secondary air cut valve 1.
05 is fully closed to stop the supply of secondary air, and at that time, the gear ratio adjustment device 18 and the throttle actuator 36 are controlled so that the engine output is maintained at an output corresponding to the accelerator operation amount. be.

Further, FIG. 3c shows the CPU 4 of the control circuit 38.
5 is a diagram showing the components of 0 divided into functional blocks, and in the figure, M10 is an engine that receives a signal from the accelerator position sensor 29 and indicates the accelerator operation amount and the rotation speed of the drive system shown in FIG. 5a. Drive system target rotation speed setting means for setting a target engine rotation speed as a target rotation speed of the drive system based on a predetermined relationship with the rotation speed, M11 is an output of the drive system target rotation speed setting means and an 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. A target engine output setting means M13 receives a signal from the engine sensor 29 and generates a target engine torque to achieve the target engine output based on the relationship shown in FIG. 5b when the accelerator operation amount is within a predetermined range. The target engine output setting means output is compared with the actual engine torque of the torque sensor 35, which is a parameter that determines the engine output in relation to the engine rotation speed, and the actual engine torque is set to become the target engine torque. Throttle valve opening control means for controlling the throttle actuator 36, M
14 receives the output of the catalyst temperature sensor 99, and
When the temperature at 8 becomes higher than the set value, the relief valve 10 is opened while maintaining the target engine output.
4 and the secondary air cut valve 105.
Next, the air supply is stopped and the fuel injection valve 1 is stopped.
1a to 11b to enrich the air-fuel ratio of the air-fuel mixture and lower the temperature of the catalyst 98.

FIG. 6 is a diagram for explaining the arithmetic processing of the CPU 40, and for convenience of explanation, 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 operation 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 is an engine rotation speed signal which is a detection signal of the engine rotation speed sensor 33, and 46 is a torque An engine torque signal which is a detection signal of the sensor 35; 106 is a catalyst temperature sensor 99;
This is the catalyst temperature signal which is the detection signal of .

In addition, in Fig. 6, characteristic curves 48 to 50 with x and y axes drawn within a square frame output the y value on the above characteristic curve when the input to the circuit is the 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 fifth signal for the signal 42 indicating the accelerator operation amount α.
49 is a second target rotation speed generation means that generates a second target rotation speed in response to the brake depression amount signal 43, 50 is a target torque generating means that generates a target engine torque in response to the accelerator operation amount signal 42.

Further, in the figure, 51 to 63, 108 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. ” is now output. 64 to 68 are adder/subtractors that add and subtract two inputs, 69 to 78 are AND gates,
79-85,109 are OR gates. Furthermore, 86-93 are various control signals obtained when the signals from the AND gates 69-78 or OR gates 79-85, 109 are "1",
Reference numeral 86 is an air-fuel ratio enrichment signal for enriching the air-fuel ratio of the air-fuel mixture, and when this signal is issued, the basic fuel injection pulse A/F is corrected to be 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. Also 88
is a supercharging up signal for increasing the supercharging amount, 89
is a supercharging down signal for reducing the supercharging amount, 90
91 is an opening up signal for increasing the opening of the throttle valve 3, 91 is an opening down signal for decreasing the throttle valve opening, and 92 is a gear ratio up signal for increasing the gear ratio of the transmission 14. , 93
is a gear ratio down signal to reduce the gear ratio,
107 is a secondary air cut signal for stopping the supply of secondary air, and 110 is a secondary air supply signal for starting to supply secondary air. And another 9
4 is a sample hold circuit, 95 is a differentiation circuit, 9
6 is a divider, and 111 is an analog switch.

Here, the actuator driven by the above various control signals has the following conditions: (1) the gear ratio change speed is slower than the engine speed change speed, and (2) the speed to return the air-fuel ratio to the lean side is faster than the engine output during acceleration. It is assumed that the two conditions of matching the increase rate are satisfied.

Next, the general operation of this apparatus will be explained using FIGS. 3 to 5.

When the engine 1 is operated, the control circuit 38
The CPU 40 controls the gear ratio adjusting device 1 so as to obtain engine output corresponding to the amount of accelerator operation, more specifically, to obtain characteristics as shown in the solid line in FIG. 5b as the engine speed and engine torque.
8. Controls the throttle actuator 36, fuel injection amount, and supercharger 6.

During operation under such control, the secondary air supply means 100
2 is activated, air is sucked into the secondary air supply passage 101 from the air cleaner, and the engine rotation speed sensor 33 detects the rotation speed of the engine 1 by the load sensor 3.
7 detects the load of the engine 1, and a catalyst temperature sensor 99 detects the temperature of the oxidation catalyst 98, and the CPU 40 receives detection signals from the load sensor 37, engine speed sensor 33, and catalyst temperature sensor 99. Executes predetermined arithmetic processing. Now, when the catalyst temperature is below the set value, the CPU4
0, the secondary air cut valve 105 is fully opened, and the relief valve 104 is adjusted to the opening degree corresponding to the engine speed and load, and then the above 2.
The amount of air sucked into the secondary air supply passage 101 is relieved to the upstream side of the air pump 104 via the bypass passage 103 according to the opening degree of the relief valve 104, and the remaining air is supplied as secondary air. Passage 101 and secondary air cut valve 1
05 and into the exhaust passage 97, the introduced secondary air re-combusts unburned components in the exhaust gas and maintains the catalyst 98 at a predetermined reaction temperature.

When the catalyst temperature exceeds the set value for some reason, the CPU 40 fully closes the secondary air cut valve 105 and fully opens the relief valve 104 to stop the supply of secondary air, and at the same time The fuel injection amount is controlled so that the air-fuel ratio becomes rich, and as a result, the catalyst temperature immediately decreases. In addition, in that case, the above CPU 4
0 controls the gear ratio adjusting device 18 and the throttle actuator 36 so that the engine output becomes a value corresponding to the accelerator operation amount in this case as well.

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

When the accelerator pedal 30 is depressed, the brake pedal 32 is usually not depressed, and the inverted output of the determining means 51 is "1".
Since AND gates 71 to 77 are all open and the engine speed Ne is higher than the minimum speed,
The output of the determining means 55 becomes "1" and the AND gate 78 is opened. In such a state, if the operation amount of the accelerator pedal 30 is less than the first set value α1, first the first target rotation speed generating means 48
A constant target rotation speed Nel is generated at adder 66.
The difference between this first target rotation speed Nel and the actual engine rotation speed Ne is calculated, and the actual rotation speed is determined as the first target rotation speed Nel.
is smaller than the target value Nel, the output of the determining means 58 becomes "1", and the signal "1" passes through the AND gate 72 and the OR gate 83 and becomes the gear ratio up signal 92, whereby the gear ratio of the transmission 14 becomes As the engine speed increases, the actual engine speed also increases. Conversely, the actual rotation speed Ne is the first target value.
When it is larger than Nel, the output of the determining means 59 becomes "1", and the signal "1" is sent to the AND gate 73.
and transmission ratio down signal 93 via OR gate 85
As a result, the gear ratio of the transmission 14 becomes smaller and the actual engine speed also decreases. Then, the actual engine speed Ne is the target speed Nel above.
When this happens, the signals from the determination means 58 and 59 both become "0", so the gear ratio is not increased or the gear ratio is decreased, and the engine speed is maintained at the target value Nel.

At the same time, the divider 96 outputs a target engine torque corresponding to the accelerator operation amount α from the accelerator operation amount signal 42 and the engine rotation speed signal 44,
The adder 67 calculates the difference between the target engine torque and the actual engine torque Te.
is smaller than the target value, the output of the determining means 60 becomes "1", and the signal is passed through the AND gate 74 and
An opening up signal 90 is generated through an OR gate 81, thereby increasing the throttle valve opening. Conversely, when the actual engine torque Te is larger than the target value, the output of the determining means 61 becomes "1", and the signal "1" is passed through the AND gate 75, the OR gate 82, and the AND gate 78 to the opening down signal 91. As a result, the throttle valve opening degree is reduced. and the actual engine torque Te
When reaches the target value, the signals from the determining means 60 and 61 both become "0", so the opening degree is not increased or decreased, and the engine torque is controlled to a value corresponding to the accelerator operation amount α.

Further, the accelerator operation amount signal 42 is differentiated by a differentiating circuit 95, but since the output of the differentiating circuit 95 is below the set value during normal operation other than during acceleration, the output of the determining means 53 becomes "1". , the signal "1" passes through the OR gate 79 and becomes the stoichiometric air-fuel ratio signal 87, whereby 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 mixture is The air is controlled to a stoichiometric air-fuel ratio λ=1. Further, in the target torque generating means 50, the accelerator operation amount α is the second
is less than the set value α2, the target torque is zero, the output of the adder 68 is negative, and the determination means 63
Since the signal becomes "1" and the signal "1" passes through the AND gate 77 and the OR gate 80 and becomes the supercharging down signal 89, the supercharger 6 does not operate.

Next, when the accelerator operation amount changes from the above-mentioned state below the first setting value α1 to a range of above the first setting value α1 and below the second setting value α2, the first target rotation speed generating means 48, a target rotational speed corresponding to the accelerator operation amount α is generated, and the gear ratio adjusting device 18 is controlled in the same manner as described above so that the actual engine rotational speed becomes the target rotational speed according to the accelerator operation amount. Ru. On the other hand, the divider 96 generates a constant target engine torque Te1, and the throttle actuator 36 generates the actual engine torque Te1.
is controlled to be a constant value Te1. 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 operation amount of the accelerator pedal 30 changes from the state below the second set value α2 to the second set value α2 or more, the first target rotation speed generating means 48 generates a constant target rotation speed Nem, The gear ratio adjustment device 18 is controlled so that the actual engine rotation speed becomes a constant target rotation speed Nem. On the other hand, the divider 96 now generates a target engine torque according to the accelerator operation amount, and the throttle actuator 36 is controlled so that the actual engine torque becomes the target value. In a region where the accelerator operation amount is equal to or greater than the second set value α2, the target torque generating means 50 generates a target engine torque corresponding to the accelerator operation amount α, and the adder 68 calculates the target engine torque and the actual engine torque. The difference from Te is calculated. When the engine reaches this range, the actual engine torque Te is obtained only by throttle valve control and is smaller than the target value.
is output, and the signal “1” is output to the AND gate 76.
Then, a supercharging up signal 88 is generated, which controls the electromagnetic clutch 10 to start supercharging and increase the engine driving force transmitted to the supercharger 6. When this actual engine torque Te becomes larger than the target value, the output of the determining means 63 becomes "1", and the signal "1" passes through the AND gate 77 and the OR gate 80 and becomes the supercharging down signal 89. The electromagnetic clutch 10 is controlled to reduce the engine driving force transmitted to the supercharger 6. When the actual engine torque Te reaches the target value corresponding to the accelerator operation amount α, the output of the adder 68 becomes zero, so supercharging is not increased or supercharging is not performed, and the supercharging amount is equal to the accelerator operation amount α. is maintained at an amount that provides engine torque corresponding to the engine torque.

Further, when acceleration is performed and the operating amount of the accelerator pedal 30 changes rapidly and exceeds the second set value α2, the same operation as above is performed, and the output of the differentiating circuit 95 is When the value exceeds the set value, the output of the determining means 52 becomes "1", and the signal "1" passes through the AND gate 71 and becomes the air-fuel ratio enrichment signal 86, which is read out according to the engine speed and intake air amount. The basic fuel injection pulse is corrected and the fuel injection valves 11a to 11d are
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 51 becomes "1", and the AND gate 7
1 to 77 are all closed, and at the same time, the signal "1" from the determining means 51 opens the AND gates 69 and 70, and the signal "1" from the determining means 51 passes through the OR gate 79 and becomes the stoichiometric air-fuel ratio signal 87. , the supercharging down signal 89 passes through the OR gate 80, and further
The opening down signal 91 is generated through the OR gate 82 and the AND gate 78, whereby the air-fuel mixture is controlled to the stoichiometric air-fuel ratio, supercharging is stopped, and the throttle valve 3 receives a signal from the determining means 54 that is "1". closed to around the lowest value. When the amount of brake depression is large, the second target rotation speed generating means 49 generates a positive second target rotation speed according to the amount of brake depression β, whereas when the amount of brake depression β is small, a negative second target rotation speed is generated. A setpoint speed of 2 is generated. Further, in the sample hold circuit 94, the moment when the brake pedal is depressed, that is, the determination means 5
Engine speed signal 4 is synchronized with signal “1” of 1.
5 is sampled and held, the adder 64 adds the second target rotation speed and the output value of the sample and hold circuit 94 to obtain the target rotation speed, and the adder 65 adds this target rotation speed and the actual rotation speed. The difference between Ne and Ne is required. When the actual rotational speed Ne is smaller than the target value, the signal of the determining means 56 is "1".
Then, the signal “1” is applied to the AND gate 69 and
Since the signal passes through the OR gate 83 and becomes the gear ratio up signal 92, 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 57 becomes "1", and the signal "1" passes through the AND gate 70 and the OR gate 85 and becomes the gear ratio down signal 93. becomes smaller and the actual engine speed also decreases. When the actual engine speed Ne reaches the target speed, the output of the adder 65 becomes zero, so the gear ratio is controlled to that value, and the engine speed is maintained at a speed corresponding to the brake depression amount β. It will be done.

Further, as described above, when the accelerator pedal 30 or the brake pedal 32 is depressed, the determination means 108 normally determines that the catalyst temperature is below the set value, so the signal is "0", and the inverted signal is "1" becomes the secondary air supply signal 110, and thereby the secondary air supply means 100 controls the supply of secondary air. When the catalyst temperature exceeds the set value, the signal of the determining means 108 becomes "1".
The signal “1” is the secondary air cut signal 10.
7, the supply of secondary air is stopped in the secondary air supply means, and the signal "1" closes the analog switch 111 to stop generating the stoichiometric air-fuel ratio signal 87, and at the same time, the signal "1" Air-fuel ratio enrichment signal 8 via OR gate 109 and AND gate 71
6, thereby the reference fuel injection pulse is corrected and applied to the fuel injection valves 11a to 11d, and the air-fuel ratio of the air-fuel mixture is richly controlled. At this time, the gear ratio is increased or decreased in the transmission 14 in the same manner as described above, while the opening of the throttle valve 3 is increased or decreased, and the engine output is maintained at a value corresponding to the amount of accelerator operation. be done.

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

() When the catalyst temperature exceeds the set value, the mixture is enriched and the supply of secondary air is stopped, and at that time, the gear ratio adjustment device and the Since the throttle actuator is controlled, the rise in catalyst temperature can be stopped without causing unpleasant torque shock.

() During steady operation, the engine torque is maintained at an appropriate value and the desired engine output is obtained by changing the engine speed, thereby reducing engine reliability and durability due to excessive increases in engine torque. It can definitely be prevented.

() Since the air-fuel mixture is controlled to the stoichiometric air-fuel ratio during steady operation, it is possible to run on air and fuel consumption, improving fuel efficiency.

() At low speeds, the engine speed is maintained at the lowest value of the stability limit and the throttle valve opening is adjusted to obtain the desired engine output, so the area in which the throttle valve is closed can be narrowed, and this makes it possible to reduce the throttle valve opening. Reduces pumping loss in engine output due to valve opening and closing, reducing deterioration in fuel efficiency.
Moreover, the stability of the engine is not impaired.

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

() At high speeds and during acceleration, supercharging is performed or the air-fuel ratio of the mixture is made rich, so sufficient high speed operation and acceleration performance can be obtained without unnecessarily increasing the engine speed. As a result, damage to the engine due to an excessive increase in engine speed can be reliably prevented, and thereby the reliability and durability of the engine can be guaranteed.

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

In the above embodiment, the drive of the automobile was controlled so as to have the characteristics shown by the solid line in FIG. Control different from that in the embodiment may be performed. Further, the engine used in the present invention may have characteristics different from those shown in FIG. 2. Further, the fuel supply means may be a carburetor instead of a fuel injection valve. Further, the rotational speed of the drive system may be detected not from the engine rotational speed but from a parameter based on the engine rotational speed such as vehicle speed.

(Effects of the Invention) As described above, according to the drive control device for a vehicle according to the present invention, a continuously variable transmission is interposed between the engine and the wheels, and an adjusting means for adjusting the gear ratio thereof is provided. , a drive means for driving the throttle valve, and a control means capable of independently controlling the adjustment means and the drive means so as to obtain an engine output corresponding to the amount of accelerator operation, and by this control means, When the catalyst becomes abnormally high temperature, the air-fuel ratio of the air-fuel mixture is enriched and the supply of secondary air is stopped, which has the effect of lowering the catalyst temperature without causing unpleasant torque shock. be.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams showing the constant fuel consumption rate region on the engine speed/torque curve plane of the conventional engine and the present invention, respectively, and FIG. 3b is a block diagram of the main parts of the above device, FIG. 4 is a block diagram of a continuously variable transmission used in the above device, and FIG. 5a is a block diagram of the first part stored in the memory 41 of the above device. A diagram showing the characteristics of the target rotation speed, FIG. 5b is a diagram for explaining the operation of the above device, and FIG. 6 is a diagram showing the CPU 40 of the above device.
FIG. 2 is a diagram for explaining arithmetic processing. 1...Engine, 3...Throttle valve, 11a
~11d...Fuel injection valve (fuel supply means), 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), 99...Catalyst temperature sensor (catalyst temperature detection means), 100...Secondary air supply 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. a driving means for the engine, a fuel supply means for supplying fuel to the engine, and an exhaust system for the engine;
a secondary air supply means for supplying secondary air; an accelerator detection means for detecting the amount of operation of the accelerator pedal;
The engine output is determined from the catalyst temperature detection means for detecting the catalyst temperature of the engine, the drive system rotation speed detection means for detecting the rotation speed of the drive system, and a parameter that determines the engine output in relation to the rotation speed of the drive system. and a drive system target that receives a signal from the accelerator detection means and sets a target rotation speed of the drive system based on a predetermined relationship between the accelerator operation amount and the rotation speed of the drive system. The rotation speed setting means compares 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, and determines whether the actual drive system rotation speed is the target rotation speed. gear ratio control means for controlling the adjustment means so that and a throttle valve opening control for comparing the output of the target engine output setting means with the actual engine output from the engine output detection means and controlling the driving means so that the actual engine output becomes the target engine output. means, receiving a signal from the catalyst temperature detecting means, and controlling the secondary air supply means so that when the catalyst temperature is equal to or higher than a predetermined temperature, the secondary air supply is stopped while maintaining the target engine output. What is claimed is: 1. A drive control device for a motor vehicle, comprising: a catalyst temperature lowering means for controlling the fuel supply means and controlling the fuel supply means so that the air-fuel ratio of the air-fuel mixture becomes rich.