JPH0429907B2 - - Google Patents

Abstract

PURPOSE:To speedily reduce engine noise by shifting the number of engine revolution to the lower revolution side, allowing the necessary reduction performance to be developed by varying a throttle valve to the closing direction, in little speed-reduction on a car which aims at improvement of fuel consumption. CONSTITUTION:In little reduction in which the brake stepping-in amount signal supplied from a brake position sensor 18 is below a prescribed value, the engine revolution-number signal supplied from an engine revolution-number sensor 20 in brake operation which is sampling-retained by receiving the brake operation signal is corrected by a minus correction value signal. The aimed engine revolution number which is reduction-corrected to the lower revolution side is compared with the actually measured engine revolution number signal supplied from the engine revolution number sensor 20, and a speed change ratio controller 9 is controlled. Thus, the number of engine revolution is set to the aimed engine revolution number of the lower revolution side in comparison with the revolution number in brake operation, and engine noise in little speed-reduction is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is for comprehensively controlling the drive system of an automobile aiming at improving fuel efficiency, for example.
Regarding a drive control device that controls engine output by mutually adjusting the opening of a throttle valve and the gear ratio of a transmission according to the amount of accelerator operation such as the amount of depression of the accelerator pedal, in particular, when the brake pedal is lightly depressed. The present invention relates to measures to reduce engine noise during so-called small decelerations, such as during slow deceleration.

(Prior art) In general, in order to improve the thermal efficiency, or fuel efficiency, of an automobile equipped with an engine such as a reciprocating engine, it is necessary to reduce mechanical losses such as pumping loss and sliding resistance, and improve combustion efficiency. is preferred. As an example, looking at mechanical loss, if the air-fuel ratio of the air-fuel mixture supplied to the engine is set constant, as shown in the constant fuel consumption rate curve in Figure 6, the mechanical loss is It is preferable to use it on the load side in terms of improving fuel efficiency. That is, the sliding resistance can be reduced on the low rotation side of the engine, and the opening degree of the throttle valve is fully open or close to fully open on the high load side of the engine, suppressing the generation of intake negative pressure and reducing popping loss.

In addition, based on this idea, we have
As shown in Publication No. 53-134162, in a car equipped with an engine equipped with an accelerator pump, the opening of the throttle valve and the gear ratio of the transmission are mutually adjusted according to the amount of depression of the accelerator pedal to increase the engine output. It has been proposed that a vehicle be driven at an optimal fuel consumption rate by providing a drive control device that controls the vehicle.

(Problem to be Solved by the Invention) By the way, for example, in such a fuel efficiency-oriented automobile, during so-called small deceleration, in which the accelerator pedal is released or the brake pedal is lightly depressed to decelerate gently, the deceleration request is Therefore, it is unnecessary to increase the engine speed to fully exert the engine braking force, and this results in an increase in engine noise.

An object of the present invention is to reduce engine noise by changing the engine speed to a low speed side while changing the throttle valve in the closing direction to exhibit the desired deceleration performance during small deceleration in a vehicle intended to improve fuel efficiency. The objective is to quickly and effectively reduce the

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention, as shown in FIG. A gear ratio adjusting device that adjusts the gear ratio of a gear transmission, a throttle valve installed in an intake passage of an engine, a throttle valve opening degree adjusting device that adjusts the opening degree of the throttle valve, and an accelerator operation amount. The engine output is determined based on the relationship between the accelerator operation amount detection means for detecting, the deceleration detection means for detecting the deceleration request of the automobile, the drive system rotation speed detection means for detecting the drive system rotation speed, and the drive system rotation speed. and engine output detection means for detecting engine output from parameters. Further, a target drive system rotation speed setting means receives the signal from the accelerator operation amount detection means and sets a target drive system rotation speed based on a predetermined relationship between the accelerator operation amount and the drive system rotation speed; The target drive system rotation speed set by the system rotation speed setting means and the actual drive system rotation speed detected by the drive system rotation speed detection means are compared, and the actual drive system rotation speed is determined to be the target drive system rotation speed. a gear ratio control means for controlling the gear ratio adjustment device so that the target engine output is set based on a predetermined relationship between the accelerator operation amount and the engine output in response to signals from the accelerator operation amount detection means; An engine output setting means compares the target engine output set by the target engine output setting means and the actual engine output detected by the engine output detection means, and sets the actual engine output to the target engine output. A throttle valve opening control means for controlling the throttle valve opening adjustment device and an output from the deceleration detecting means are used to open the throttle valve so as to change the throttle valve in the closing direction when the deceleration request is less than a predetermined value. The present invention is further provided with a control means comprising a correction means for controlling the speed ratio control means and the speed ratio control means so as to make the engine rotation speed lower than the rotation speed at the time of requesting deceleration.

(Function) As a result, when there is a small deceleration request for the automobile, the throttle valve changes in the closing direction to achieve a gentle deceleration that matches the deceleration request.
By changing the engine speed to the lower side, engine noise can be quickly suppressed to a low level.

(Effects of the Invention) Therefore, according to the present invention, in a vehicle oriented to improve fuel efficiency as described above, during a small deceleration with little deceleration request, the engine noise can be reduced while exerting a gentle deceleration that meets the deceleration request. can be quickly and effectively reduced, improving drivability during small decelerations,
It is possible to improve quietness.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

FIG. 1 shows an overall schematic configuration of an embodiment of the present invention. In FIG. 1a, 1 is an engine, and 2 and 2 are left and right wheels driven by the driving force (engine output Pd) of the engine 1 via a differential gear 3. In FIG. A continuously variable transmission 4 whose gear ratio Kg changes continuously is interposed between the engine 1 and the differential gear 3. A gear ratio adjustment device 5 is provided to adjust the gear ratio Kg. The rate of change in the gear ratio Kg by the gear ratio adjusting device 5 is set to be slower than the rate of change in the engine rotational speed Ne, so as not to cause a gear shift shock when the engine 1 decelerates or decelerates. There is. 6 is a clutch interposed between the engine 1 and the continuously variable transmission 5.

Reference numeral 7 denotes an intake passage that supplies intake air to the engine 1. A throttle valve 8 for controlling the amount of intake air is interposed in the middle of the intake passage 7. A throttle valve opening adjustment device 9 is provided to adjust the opening θ. This throttle valve opening θ is approximately equivalent to the engine load, that is, the engine torque Te.
The downstream end of the intake passage 7 is branched according to the number of cylinders (four cylinders in the figure), and each branch part 7a, 7a...
are provided with fuel injection valves 10, 10, . . . for injecting fuel. Furthermore, the intake passage 7 upstream of the throttle valve 8 is provided with a bypass passage 11 that bypasses the intake passage 7. A feeder 13 is provided, and the supercharger 13 supercharges intake air. An electromagnetic clutch 14 for controlling the turbocharger 13 on and off is located in the middle of the transmission line to the turbocharger 13.
is interposed. Incidentally, reference numeral 15 denotes a check valve interposed in a portion of the intake passage 7 corresponding to the bypass passage 11 to prevent supercharged air from flowing backward when the supercharger 13 is operated.

On the other hand, 16 is an accelerator position sensor constituting an accelerator operation amount detection means that detects the amount of depression α of the accelerator pedal 17 as the amount of accelerator operation, and 18 is the amount of depression β of the brake pedal 19 as a request for deceleration of the automobile. This is a brake position sensor that constitutes deceleration detection means. Also,
Reference numeral 20 denotes an engine rotation speed sensor as a drive system rotation speed detection means for detecting the engine rotation speed Ne based on the rotation speed of the input shaft 21 of the continuously variable transmission 4; 23 is a throttle position sensor that detects the opening degree θ of the throttle valve 8; and 24 is an air flow meter that detects the amount of intake air in the intake passage 7. . Each of these sensors 16,
The respective outputs of the air flow meters 18, 20, 22, 23 and the air flow meter 24 are input to a control means 25 consisting of an analog computer or a microcomputer. The control means 25 is connected to the speed ratio adjustment device 5, the throttle valve opening adjustment device 9, the fuel injection valve 10, and the electromagnetic clutch 14, and is configured to control each of these.

The continuously variable transmission 4 and its gear ratio adjustment device 5
The specific structure of is shown in FIG. As shown in FIG. 2, the continuously variable transmission 4 is a known V-belt type continuously variable transmission (for example, see Japanese Patent Application Laid-Open No. 56-46153), and is provided on an input shaft 21 from the engine 1. A primary pulley 30, a secondary pulley 31 provided on the output shaft 26, both pulleys 30,
31 and a V-belt 32 wound around between the belts 31 and 31.
The primary pulley 31 is a fixed pulley 33.
, a movable pulley 34 that can move forward and backward opposite the fixed pulley 33 , and a hydraulic chamber 35 formed at the back of the movable pulley 34 .
A planetary gear 36 meshingly interposed between the fixed pulley 33 and the planetary gear 36 and a pressure oil supply control of a manual valve 46 operated in response to manual operation of a shift lever (not shown) are used to control the planetary gear 36 when in the forward gear L. The gear 36 is fixed to the input shaft 21 side, and the fixed pulley 33 (primary pulley 30) is rotated in the same direction as the input shaft 21. When the gear 36 is in reverse gear R, the planetary gear 36 is fixed to the casing 30a side, and the fixed pulley 33 is rotated in the same direction as the input shaft 21. A hydraulic clutch 37 is provided for rotating the input shaft 21 in a direction opposite to that of the input shaft 21. Further, the secondary pulley 31 similarly includes a fixed pulley 38, a movable pulley 39 that can freely move forward and backward in opposition to the fixed pulley 38, and a hydraulic chamber 40 formed at the back of the movable pulley 39. Each hydraulic chamber 35, 40 of the primary pulley 30 and secondary pulley 31 is connected to the oil pump 4.
The secondary pulley 31 is connected to the movable pulley 34 of the primary pulley 30 through the regulator valve 42.
A secondary valve 43 for controlling the supply and discharge of pressure oil to the hydraulic chambers 40 is provided, and by controlling the supply and discharge of pressure oil to the respective hydraulic chambers 35 and 40, the The structure is such that the distance between the fixed pulleys 33, 38 and the movable pulleys 34, 39 changes, and accordingly, the V-belt 32 moves up and down within the distance, so that the gear ratio changes steplessly. There is.

A first electromagnetic valve 44 that controls the supply of pressure oil to the hydraulic chamber 35 is interposed between the hydraulic chamber 35 of the primary pulley 30 and the regulator valve 42 . The first electromagnetic valve 44
The hydraulic chamber 3 of the primary pulley 30 is opened in response to a gear ratio down signal, which will be described later.
5, the movable pulley 34 is advanced toward the fixed pulley 33 to narrow the gap between the two, and the secondary valve 43 is controlled to relieve the pressure oil chamber 40 of the secondary pulley 31 and release the pressure oil chamber 40 of the secondary pulley 31. The distance between the fixed pulley 38 and the movable pulley 39 is widened, thereby controlling the gear ratio Kg to be small. In addition, the hydraulic chamber 35 of the primary pulley 30 and the first electromagnetic valve 44
A second electromagnetic valve 45 for controlling the discharge of pressure oil from the hydraulic chamber 35 is interposed between the two. The second electromagnetic valve 45 opens the primary pulley 3 by opening in response to a gear ratio up signal, which will be described later.
0 hydraulic chamber 35 and its movable pulley 3
4 is moved backward with respect to the fixed pulley 33 to widen the gap between the two, and as a result, the secondary valve 4
3, pressure oil is supplied to the pressure oil chamber 40 of the secondary pulley 31, and the distance between the fixed pulley 38 and the movable pulley 39 is narrowed, and thus the gear ratio is changed.
It is controlled to increase Kg. With these first and second electromagnetic valves 44, 45,
A gear ratio adjustment device 5 is configured to adjust the gear ratio of the continuously variable transmission 4. Note that 47 is a clutch valve for nullifying the transmission relationship between the primary pulley 30 and the secondary pulley 31 via the V-belt 32.

The control means 25, as shown in FIG. 1b,
Target drive system rotation speed setting means 25a receives a signal from the accelerator position sensor 16 and sets a target engine rotation speed Ne (target drive system rotation speed) based on a predetermined relationship between the accelerator operation amount and the engine rotation speed. and the target drive system rotation speed setting means 25a.
The target engine speed Ne set in is compared with the actual engine speed Ne' detected by the engine speed sensor 20, and the actual engine speed is determined.
Gear ratio control means 25 that controls the gear ratio adjusting device 5 so that Ne' becomes the target engine speed Ne
b, target engine output setting means 25c that receives a signal from the accelerator position sensor 16 and sets a target engine torque Te (target engine output) based on a predetermined relationship between the accelerator operation amount and the engine output; Target engine output setting means 2
The target engine torque Te set in step 5c is compared with the actual engine torque Te' detected by the engine torque sensor 22, and the throttle valve opening is adjusted so that the actual engine torque Te' becomes the target engine torque Te. A throttle valve opening degree control means 25d that controls the adjustment device 9 receives the output of the brake position sensor 18, and when the deceleration request is less than a predetermined value, opens the throttle valve 8 so as to change the throttle valve 8 in the closing direction. degree control means 25d
and a correction means 25e that controls the gear ratio control means 25b so as to control the engine speed and to make the engine speed lower than the speed at which the deceleration is requested.

Next, the operation of the control means 25 will be explained with reference to the logic diagram shown in FIG. Figure 3 shows the accelerator depression amount α (accelerator operation amount) and the required engine output.
The case where it is considered as Pd is shown.

As shown in FIG. 3, the control means 25 has a target engine rotation speed corresponding to the accelerator depression amount α in advance.
It has a first map _M1 that maps Ne. During steady operation of the automobile, when the accelerator depression amount α signal from the accelerator position sensor 16 is input, the target engine rotation speed Ne corresponding to this accelerator depression amount α is determined in the first map _M1 . , this target engine speed Ne signal is used as a comparator
At C ₁ , compare it with the measured engine speed Ne' signal from the engine speed sensor 20, and calculate the deviation ΔNe.
When (=Ne−Ne′) is ΔNe>0, the gear ratio up signal is adjusted on the premise that the brake depression amount β signal from the brake position sensor 18 is below a predetermined value (that is, there is no brake depression). It outputs to the second electromagnetic valve 45 of the device 5 and changes the gear ratio Kg of the continuously variable transmission 4 (that is, the engine rotation speed).
On the other hand, when ΔNe<0, a gear ratio down signal is output to the first electromagnetic valve 44 of the gear ratio adjusting device 5 on the assumption that the brake is not depressed, and the gear ratio Kg of the continuously variable transmission 4 (that is, the engine Feedback control is performed to reduce the engine speed Ne to the target engine speed Ne. Also,
During steady operation, upon input of the accelerator depression amount α signal, the accelerator depression amount α signal, that is, the engine output Pd signal, is divided by the engine rotation speed Ne signal from the engine rotation speed sensor 20 at that time in the divider Di. The target engine torque Te is determined, and this target engine torque Te signal is compared with the measured engine torque Te' signal from the engine torque sensor ₂₂ using a comparator C2, and the deviation ΔTe (=Te−Te') is determined by ΔTe. >0, a throttle valve opening up signal is output to the throttle valve opening adjustment device 9 on the assumption that the brake is not depressed as described above, and the opening θ of the throttle valve 8 (that is, engine torque) is increased. ΔTe
<0, a throttle valve opening down signal is output to the throttle valve opening adjustment device 9, and the target engine torque Te (target The throttle valve opening degree θ) is controlled.

Here, to explain the first map _M1 with reference to FIG. 5, the engine performance curve (engine speed Ne-engine torque Te curve) of the engine 1 is set as shown in FIG. 5a. That is, during steady operation, as shown in the characteristic curve A in Fig. 5a, in order to maximize the thermal efficiency, that is, the fuel efficiency, of the engine 1, the rotation speed should be set at the low rotation side (the side where the sliding resistance decreases) and at the high load side (the side where the sliding resistance decreases). When the engine output Pd is below the first set value (Pd ₁ in the figure) (that is, when the accelerator depression amount α is below the first predetermined value), the engine The engine torque Te changes while the rotational speed Ne is maintained at the lowest engine rotational speed Nel that can ensure stable engine operation, and the engine output Pd is greater than the first set value (Pd ₁ ). WOT (Wide Open
The engine torque Te is held at the maximum engine torque Tem along the (Throttle) curve or its vicinity, that is, the throttle valve opening θ is held at the fully open or near fully open set value θm, and the engine speed Ne changes, resulting in engine output. Pd is the second setting value (Pdm)
In the above case (when the accelerator depression amount α is equal to or higher than the second predetermined value), the engine torque Te is further increased by the operation of the torque increase device (supercharger 13 and air-fuel ratio enrichment means described above) at the maximum engine speed Nem. It has a characteristic that increases. Based on this engine performance curve A (Ne-Te curve), engine output
When Pd (that is, accelerator depression amount α) is taken as the horizontal axis and converted into an engine output Pd (accelerator depression amount α)-engine rotation speed Ne curve, the characteristic curve shown in FIG. 5b is obtained. This characteristic curve in FIG. 5b corresponds to the first map _M1 . In other words, this first map M ₁
The engine output is determined by the value of and the divider Di mentioned above.
Based on the value of engine torque Te obtained by dividing Pd (accelerator depression amount α) by engine speed Ne, during steady operation of the car, depending on the accelerator depression amount α,
Gear ratio Kg that controls engine speed Ne and throttle valve opening θ that controls engine torque Te
are mutually adjusted so that the engine output Pd corresponds to the accelerator depression amount α, and the engine performance characteristics conform to the Ne-Te curve A in Figure 5a, which provides the best fuel efficiency. ing.

On the other hand, when accelerating by depressing the accelerator pedal 17, the accelerator depressing amount α signal from the accelerator position sensor 16 is differentiated by the differentiating circuit 27 to obtain the rate of change dα/dt of the accelerator depressing. Then, this rate of change dα/dt is the second
During so-called medium acceleration, which is determined by the map _M2 to be equal to or higher than a predetermined value, the correction value signal of the second map M2 is added to the accelerator depression amount α signal from the accelerator position sensor ₁₆ at the addition point _P1 for correction. Thereafter, based on this addition-corrected accelerator depression amount α ₁ signal, a gear ratio up signal or a gear ratio down signal is output to the gear ratio adjusting device 5 by comparing it with the actual engine rotation speed as in the above-mentioned steady operation. In addition to performing feedback control, a throttle valve opening up signal or down signal is output to the throttle valve opening adjustment device 9 based on comparison with the measured engine torque, thereby controlling the engine output Pd to correspond to the accelerator depression amount α. After making sure that the output is higher than the engine output, fixed point deceleration is performed.

Furthermore, the target accelerator depression amount α signal from the accelerator position sensor 16 is sent to the comparator _C3 , and the engine rotation speed Ne from the engine rotation speed sensor 20 is sent to the comparator C3.
Actual engine output Pd′ (=Ne・Te) obtained by multiplying the signal and the engine torque Te signal from the engine torque sensor 22 by the multiplier Mu
When compared with the signal and the deviation (α-Ne・Te) is determined to be greater than a predetermined value by the third map _M3 , that is, during sudden acceleration when the accelerator pedal 17 is suddenly and greatly depressed, at the above-mentioned addition point _P1. The correction value signal of the third map _M3 is added to the accelerator pedal depression amount α signal from the accelerator position sensor 20 and corrected so that it becomes the maximum engine output value Pmax, and from then on based on this maximum engine output value Pmax signal The gear ratio Kg and the throttle valve opening θ are feedback-controlled in the same way as during the above-mentioned medium acceleration.
Therefore, engine output Pd is the maximum engine output value
Acceleration is controlled so that Pmax is achieved.

In addition, the rate of change of the accelerator depression mentioned above dα/dt
During so-called rapid acceleration, where the 4th map _M4 determines that the engine speed is higher than a predetermined value, the "1" signal outputs an air-fuel ratio rich signal to the fuel injection valves 10, assuming that the brake is not depressed, as described above. , by increasing the amount of fuel injected from the fuel injection valves 10..., the engine torque Te is immediately increased further than the maximum engine torque Tem,
Thereafter, by feedback control based on the value of the first map _M1 and the value of the divider Di, the engine output Pd corresponding to the accelerator depression amount α is held constant, and the engine speed Ne reaches the target engine speed. This increases the speed of the change, making quick acceleration responsive and smooth. Incidentally, when the accelerator depression change rate dα/dt is less than or equal to the predetermined value according to the fifth map _M5 , an air-fuel ratio set value signal is outputted to the fuel injection valve 10 by the "1" signal, and the air-fuel ratio set value signal is outputted to the fuel injection valve 10. The fuel injection amount from... is held at the set value. It is preferable that the speed at which the air-fuel ratio is returned to the lean side matches the rate of increase in engine output during acceleration, since torque shock can be prevented.

In addition, at the time of regulating the vehicle speed by changing the depression of the accelerator pedal 16 in the return direction, the throttle valve opening θ and the engine rotational speed are adjusted.
First, the divider Di
Control is performed only by the value of , and the accelerator depression amount α
In response to the decreasing change in , only the throttle valve opening immediately decreases, causing the engine output Pd to decrease to the target engine output. After that, the first map
Control based on the value of M ₁ and the value of the divider Di keeps the target engine output constant and changes the gear ratio.
Kg (engine speed Ne) and throttle valve opening θ change to the target values, so that speed regulation is performed smoothly with good responsiveness and without torque shock.

Furthermore, the accelerator depression amount α is the sixth map.
When the engine speed is high and the load is higher than the second predetermined value due to _M6 , the target engine torque Te signal from the sixth map _M6 is compared with the measured engine torque Te' signal from the engine torque sensor 22 using the comparator _C4 . , the deviation ΔTe (=Te−Te′) is ΔTe>0
When , the engine torque is increased by outputting a supercharging up signal to the electromagnetic clutch 14 and operating the supercharger 13 assuming that the brake is not depressed.
While Te is increased, when ΔTe<0, a supercharging down signal is output to the electromagnetic clutch 14 on the assumption that the brake is not depressed, and the operation of the supercharger 13 is stopped, thereby increasing the engine torque Te.
The target engine torque Te is controlled by feedback control so as to reduce the torque Te.

On the other hand, when the brake position sensor 18 detects the depression of the brake pedal 19 and the depression amount β exceeds a predetermined value according to the seventh map _M7 , that is, when decelerating, the "1" signal determines the throttle valve opening. It outputs a down signal, a supercharging down signal, and an air-fuel ratio set value signal, and also prevents the output of each signal associated with the accelerator pedal depression through the flip-flop 28 and inverter _I1 , thereby reducing the opening degree of the throttle valve 8. , forcibly stops the operation of the supercharger 13 and maintains the set value of the air-fuel ratio, and further outputs a fuel-on signal to the fuel injection valves 10 by the "0" signal inverted by the inverter _I2 . At the same time, outputting a fuel off signal to the fuel injection valves 10 on the premise that the engine speed Ne is equal to or higher than a predetermined value,
Fuel injection from the fuel injection valves 10 is stopped, thereby ensuring good deceleration performance during brake operation.

Then, during so-called small deceleration when the brake depression amount β signal from the brake position sensor 18 is determined to be less than the first predetermined value by the eighth map _M8 , the sampling circuit 29 receives the brake operation signal and holds the sample. The engine rotational speed Ne signal from the engine rotational speed sensor 20 during the brake operation is corrected by the negative correction value signal from the eighth map _M8 at the addition point _P2 , and the engine rotational speed Ne signal is corrected to decrease toward the lower rotational speed side. The comparator C ₅ converts the target engine speed Ne ₁ signal into the measured engine speed from the engine speed sensor 20.
Compared with the Ne′ signal, its deviation ΔNe (=Ne ₁ −
Ne') is ΔNe > 0, a gear ratio up signal is output to the gear ratio adjustment device 5 on the assumption that the brake pedal 19 is depressed in response to the brake operation signal, and the gear ratio Kg, that is, the engine rotation speed Ne is increased, while ΔNe When <0, a gear ratio down signal is output to the gear ratio adjustment device 5 on the assumption that the brake pedal 19 is depressed, and feedback control is performed to decrease the gear ratio Kg, that is, the engine speed Ne, and thus the engine speed Ne is set to a target engine rotational speed Ne ₁ that is lower than the rotational speed during brake operation, so that engine noise during small decelerations with few deceleration requests is quickly and effectively reduced.

In addition, the above-mentioned brake depression amount β signal is shown in the 8th map.
During so-called medium deceleration, which is determined to be between the first predetermined value and a second predetermined value larger than the first predetermined value by _M8 , the engine rotation speed Ne signal during brake operation is output from the sampling circuit 29. is output as is without being corrected by the zero correction value signal from the eighth map _M8 at the addition point _P2 , and from then on, the gear ratio up signal or down signal is generated by comparison with the measured engine speed as in the case of the above-mentioned small deceleration. is output to the gear ratio adjusting device 5 for feedback control,
Therefore, the engine speed Ne is held constant at the same speed as when the brake is operated, thereby reducing engine noise as much as possible while ensuring engine braking performance that meets the deceleration request during medium deceleration. .

Furthermore, during so-called sudden deceleration when the brake depression amount β signal is judged to be equal to or higher than the second predetermined value by the eighth map _M8 , the engine rotational speed Ne signal during brake operation from the sampling circuit 29 is added to the summation point _P2. Then, based on the target engine speed Ne ₂ corrected by the plus correction value signal from the eighth map _M8 , and corrected to increase toward the high speed side, from then on, comparison with the measured engine speed is performed in the same manner as during the above-mentioned small deceleration. Therefore, the engine rotation speed Ne is set to the target engine rotation speed Ne ₂ , which is higher than the rotation speed during brake operation, thereby maximizing engine braking performance during sudden deceleration when a large deceleration request is required. I try to make the most of it.

When the engine speed Ne′ signal from the engine speed sensor 20 is below a predetermined value, a throttle valve opening up signal and a fuel on signal are output to forcibly increase the opening θ of the throttle valve 8. At the same time, fuel is injected from the fuel injection valves 10 to ensure operability of the engine at extremely low rotation speeds. In addition, engine rotation speed
When the Ne' signal exceeds a predetermined value, output of the throttle valve opening down signal and the aforementioned fuel off signal are permitted.

Next, when returning from the deceleration operation to steady operation, when the brake pedal 19 is released,
The brake depression amount β signal from the brake position sensor 18 becomes less than a predetermined value, and the seventh map _M7
The " ₁ " signal which is obtained by inverting the "0" signal from Accordingly, the gear ratio Kg, that is, the engine rotation speed Ne, is controlled to decrease so as to reach the target value. After that, when the engine speed Ne approaches the target value, a "1" signal is output from the ninth map _M9 , and this "1" signal generates a throttle valve opening up signal and a throttle valve opening down signal to the throttle valve opening adjustment device 9. The throttle valve opening θ is increased and controlled to reach the target value. Then, when the throttle valve opening θ approaches the target value, the above-mentioned flip-flop 28 is reset by the "1" signal from the 10th map _M10 , thereby resetting the air-fuel ratio rich signal whose output was inhibited during deceleration. , a supercharging up signal, and a supercharging down signal. Therefore, when returning from deceleration operation to steady operation, the control time for increasing the throttle valve opening θ is shortened as much as possible to suppress fuel consumption and return with low fuel consumption.

Therefore, when the vehicle is decelerating slightly as described above, when the brake pedal 19 is lightly depressed, the engine speed increases, as shown in characteristic curve B in FIG. 5a.
While Ne remains almost constant, the engine Te, that is, the throttle valve opening θ, immediately changes to the throttle valve fully open characteristic curve C.
After the throttle valve 8 becomes fully closed, the engine speed Ne decreases toward the low speed side along the throttle valve fully closed characteristic curve C. As a result, by fully closing the throttle valve 8, a gentle deceleration that matches the small deceleration with little deceleration request can be obtained, and the engine noise can be quickly reduced by decreasing the engine speed. It is possible to improve drivability and quietness during small decelerations.

Incidentally, in the above embodiment, a case has been described in which the accelerator depression amount α is regarded as the required engine output Pd, but it may also be regarded as the required vehicle speed Vc. In this case, as shown by the broken line in FIG. As shown in FIG. 4, the control means 25 compares the accelerator depression amount α signal from the accelerator position sensor 16 with the vehicle speed signal Vc signal from the vehicle speed sensor 50.
_C6 to find the deviation, and this deviation may be controlled by a so-called P-I operation in which an integral operation and a proportional operation are performed in parallel to calculate the engine output Pd. Also, in this case, engine output
Since the Pd calculation includes an integral element, feedback is applied so that the difference between the accelerator depression amount α and the vehicle speed Vc is always zero, and during steady operation, the difference between the two becomes zero, and the engine output Pd is equal to the running load. Match.

Furthermore, in the above embodiment, during steady operation of the automobile,
Although the gear ratio Kg and the throttle valve opening θ are changed in accordance with the accelerator depression amount α to obtain the required engine output with the minimum fuel consumption, the invention is not limited to this, and the point is that the accelerator depression amount Any configuration may be used as long as the gear ratio Kg and the throttle valve opening θ are changed so that the corresponding engine output is obtained.

Further, in the above embodiment, the brake position sensor 18 is used as a deceleration detection means for detecting a request for deceleration of the automobile, but an accelerator position sensor for detecting zero accelerator operation may also be used. Various means can be adopted, such as detecting changes in intake negative pressure that occur due to air pressure. Also,
In the above embodiment, the control means 25 was constructed using an analog computer, but it is also applicable to a system constructed using a digital computer.

Furthermore, in the above embodiments, the air-fuel ratio is set to a constant value, but it is also possible to use a system in which the air-fuel ratio is changed depending on the engine load.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention; FIG. 1 is a schematic overall configuration diagram, FIG. 2 is a schematic sectional view of a continuously variable transmission and its gear ratio adjusting device, and FIG. 3 explains the operation of the control means. Logic diagram, FIG. 4 is a partial operation explanatory diagram showing only the modified part as a modification of the control means, FIGS. 5 a and b are explanatory diagrams respectively explaining the engine performance characteristics and the first map, and FIG. It is a fuel consumption rate curve diagram. DESCRIPTION OF SYMBOLS 1... Engine, 2... Axle, 4... Continuously variable transmission, 5... Gear ratio adjustment device, 7... Intake passage, 8
... Throttle valve, 9 ... Throttle valve opening adjustment device, 16 ... Accelerator position sensor (accelerator operation amount detection means), 18 ... Brake position (deceleration detection means), 20 ... Engine rotation speed sensor ( Drive system rotation speed detection means), 22...Engine torque sensor (engine output detection means), 2
5... Control means, 25a... Target drive system rotation speed setting means, 25b... Gear ratio control means, 25c...
Target engine output setting means, 25d... Throttle valve opening control means, 25e... Correction means.

Claims (1)

[Scope of Claims] 1. A continuously variable transmission interposed between an engine and wheels, a gear ratio adjustment device for adjusting the gear ratio of the continuously variable transmission, and a gear ratio adjusting device disposed in an intake passage of the engine. A throttle valve, a throttle valve opening adjustment device that adjusts the opening of the throttle valve, an accelerator operation amount detection means that detects an accelerator operation amount, a deceleration detection means that detects a request for deceleration of an automobile, and a drive system rotation. drive system rotation speed detection means for detecting the number of rotations; and engine output detection means for detecting the engine output from a parameter in which the engine output is determined in relation to the drive system rotation speed; a target drive system rotation speed setting means for receiving a signal and setting a target drive system rotation speed based on a predetermined relationship between an accelerator operation amount and a drive system rotation speed; and a target set by the target drive system rotation speed setting means. Comparing the drive system rotation speed and the actual drive system rotation speed detected by the drive system rotation speed detection means, and controlling the gear ratio adjustment device so that the actual drive system rotation speed becomes the target drive system rotation speed. and target engine output setting means that receives a signal from the accelerator operation amount detection means and sets a target engine output based on a predetermined relationship between the accelerator operation amount and the engine output. The target engine output set by the setting means is compared with the actual engine output detected by the engine output detection means, and the throttle valve opening adjustment device is controlled so that the actual engine output becomes the target engine output. Throttle valve opening control means; receiving the output of the deceleration detection means, controls the throttle valve opening control means so as to change the throttle valve in the closing direction when the deceleration request is below a predetermined value, and also controls the engine rotational speed. 1. A drive control device for an automobile, comprising a control means comprising a correction means for controlling the gear ratio control means so that the rotational speed is lower than the rotational speed at the time of deceleration request.