JPH0578456B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention controls the gear ratio in a continuously variable transmission mechanism provided in the power transmission path from the engine of a vehicle to the drive wheels, and changes the engine load. The present invention relates to a control device for a vehicle power train that performs control.

(Prior art) In vehicles, in order to efficiently transmit the output of the engine to the wheels, which are driven objects, a transmission mechanism is disposed between the engine and the wheels, and the output of the engine is transmitted to the wheels via the transmission mechanism. As this transmission mechanism, one that employs a continuously variable transmission mechanism that can continuously change the transmission ratio within a predetermined range is known. The continuously variable transmission mechanism installed in such vehicles is adjusted by adjusting the vehicle speed or engine rotation speed and the operation of an accelerator adjustment part such as an accelerator pedal, as described in Japanese Patent Application Laid-Open No. 55-76709. The gear ratio is controlled based on the throttle valve opening. In such a case, the gear ratio of the continuously variable transmission mechanism is usually controlled so that the engine rotational speed, and therefore the input rotational speed of the continuously variable transmission mechanism, is uniquely determined by the throttle valve opening. be done. That is, the gear ratio is controlled so that a constant engine speed is obtained for each throttle valve opening value, and therefore a constant engine output is obtained.

By the way, while the vehicle is driving, the driver of the vehicle depresses the accelerator pedal and increases the opening of the throttle valve to accelerate the vehicle to a desired speed. In other words, in order to maintain a feeling of acceleration, it is desirable that a constant increase in the throttle valve opening degree be maintained at a predetermined magnitude.

However, in the case of a vehicle equipped with the above-mentioned continuously variable transmission mechanism, the continuously variable transmission mechanism is capable of changing the speed so that the engine speed is kept constant for each throttle valve opening value. Since ratio control is performed, the engine speed increases to a predetermined value immediately after the accelerator pedal is depressed, and
After the engine output increases accordingly, the increased engine output is maintained continuously, and the vehicle runs at a constant engine output. Then, while the vehicle is running at a constant engine output after this acceleration, the vehicle speed increases, and running resistance increases accordingly. Despite the increase in running resistance that accompanies the increase in vehicle speed, the engine output remains constant, so even if the driver continues to press the accelerator pedal at a constant rate, the driving force of the vehicle will not decrease. The acceleration gradually decreases.
Therefore, the driver is dissatisfied with the sense of acceleration. Furthermore, during acceleration or deceleration, the gear ratio control of the continuously variable transmission mechanism is performed immediately to keep the engine speed constant, so the engine sound does not change dynamically and the driver does not have any audible complaints. You will feel it.

Therefore, in order to solve the above-mentioned problems, the applicant first set a target vehicle acceleration according to the operation of an accelerator adjustment part such as an accelerator pedal in Japanese Patent Application No. 58-205043. In order to continuously achieve the set target vehicle acceleration, an electronically controlled continuously variable transmission device that controls the gear ratio of the continuously variable transmission mechanism was further developed in Japanese Patent Application No. 58-205051 as described above. In order to achieve the target vehicle acceleration with minimum fuel consumption, we have proposed a vehicle powertrain control device that controls the opening of the throttle valve in addition to controlling the gear ratio of the continuously variable transmission mechanism.

According to such electronically controlled continuously variable transmission and vehicle power train control device, during the acceleration period,
As the running resistance increases due to the increase in vehicle speed, the running driving force increases, and this increase in running driving force can be achieved under optimal fuel consumption conditions, so that the required constant vehicle acceleration can be reduced to the necessary minimum. By being able to continuously achieve this with a limited amount of fuel, it is possible to provide the driver of the vehicle with a sufficiently satisfying feeling of acceleration when stepping on the accelerator for acceleration, and it is also possible to effectively save fuel.

By the way, normally, when a vehicle driver wants to increase the vehicle speed, he or she depresses the accelerator pedal, expecting the vehicle speed to increase with an acceleration corresponding to the amount of depressing, and when the desired vehicle speed is reached, the driver depresses the accelerator pedal. After that, it is often desired that the vehicle travels at a constant speed. Therefore, even in a vehicle equipped with the above-mentioned continuously variable transmission mechanism, under optimal fuel consumption conditions, when the accelerator pedal is depressed (acceleration operation) and subsequently held, the vehicle is It is desirable that the vehicle is accelerated in response to the depression of the accelerator pedal, and that the acceleration is stopped and the vehicle runs at a constant speed when the accelerator pedal is released and held.

(Object of the Invention) In view of the above, the present invention provides that, in a state where an operation to increase the amount of operation of the required engine output setting means, such as an operation of pressing an accelerator pedal, and a subsequent holding state, the An operation that allows a constant vehicle acceleration corresponding to the operation of the required engine output setting means to be continuously achieved with minimum fuel consumption, and that reduces the amount of operation of the required engine output setting means, such as a return operation of an accelerator pedal. A vehicle powertrain that controls a continuously variable transmission mechanism and an engine output adjustment means arranged in a power transmission path of a vehicle so that a constant vehicle speed can be maintained at a minimum fuel consumption in a state in which the vehicle is operated, and in a state in which the engine is maintained. The purpose is to provide a control device for.

(Structure of the Invention) As the basic structure of the control device for a vehicle power train according to the present invention is shown in FIG. A gear ratio adjustment unit that changes the ratio, an engine output adjustment unit that changes the engine load, such as a throttle valve drive unit that changes the opening degree of the throttle valve, and a throttle control unit that changes the engine load according to the amount of operation of the accelerator pedal. Like an accelerator adjustment section that sends a drive signal to a valve drive section,
A required engine output setting means for activating the engine output adjusting means, a detecting section for detecting the operation state of the required engine output setting means, and a speed ratio adjusting section for causing a change in the speed ratio of the continuously variable transmission mechanism. and a control unit that causes a change in engine load, and the control unit is configured such that the operation of the requested engine output setting means detected by the detection unit increases the amount of operation of the requested engine output setting means. When the target vehicle acceleration setting means sets the target vehicle acceleration in response to this operation, the operation of the requested engine output setting means that is also detected by the detection section reduces the amount of operation of the requested engine output setting means. target vehicle speed setting means for setting a predetermined target vehicle speed, and a constant acceleration driving state in which the vehicle continuously achieves the above-mentioned target vehicle acceleration or the above-mentioned target vehicle speed is continuously achieved. A control signal is sent to the gear ratio adjusting section and the engine output adjusting means to change the gear ratio of the continuously variable transmission mechanism and the engine load in order to maintain the constant vehicle speed running state under the optimal fuel consumption state. The control signal supply means includes control signal supply means.

With this configuration, depending on the vehicle driver's control operation on the required engine output setting means such as the accelerator adjustment section, the constant acceleration running state and constant speed running state desired by the vehicle can be set to the minimum fuel consumption. It can be taken in quantity.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows an outline of a drive control section of a vehicle to which an example of a control device for a vehicle power train according to the present invention is applied. In FIG. 2, a throttle valve 3 for changing the load of the engine 1 is disposed in an intake passage 2 of the engine 1. As shown in FIG. This throttle valve 3 is driven to open and close by a throttle actuator 4, and its opening degree is detected by a throttle position sensor 5. In addition,
The end of the intake passage 2 on the downstream side of the throttle valve 3 forms branch passages 2a, 2b, 2c, and 2d that communicate with each cylinder. A fuel injection valve (not shown) is installed.

An output shaft 6 of the engine 1 is connected to a continuously variable transmission 9 via a clutch 7 and a switching gear train 8, and an output shaft 10 of the continuously variable transmission 9 is connected to drive wheels 12 via a differential gear 11. It is connected.

Also, an engine rotation speed detection sensor 13 that detects the rotation speed of the output shaft 6 of the engine 1, a clutch output shaft rotation speed detection sensor 15 that detects the rotation speed of the output shaft 14 of the clutch 7, and an input shaft of the continuously variable transmission 9. 16
The transmission input rotation speed detection sensor 17 detects the rotation speed of the output shaft 10 of the continuously variable transmission 9, and the transmission output shaft rotation speed detection sensor 18 detects the rotation speed of the output shaft 10 of the continuously variable transmission 9. It is installed at the location of Throttle position signal P5 from the aforementioned throttle position sensor 5, engine speed signal P2 from the above-mentioned engine speed detection sensor 13, and clutch output shaft rotation speed from the clutch output shaft rotation speed detection sensor 15. signal P4,
The transmission input shaft rotation speed signal P6 from the transmission input shaft rotation speed detection sensor 17 and the transmission output shaft rotation speed signal P8 from the transmission output shaft rotation speed detection sensor 18 are transmitted to the interface section 19 and the CPU 20. and a memory 21 as main components.

Further, the amount of depression of the accelerator pedal 23 operated by the driver, that is, the accelerator opening is detected by the accelerator opening detection sensor 24, and the depression state of the brake pedal 25 is detected by the brake operation detection sensor 24.
6, and furthermore, the shift position of the shift lever 27 is detected by the shift lever position detection sensor 2.
8, and the slope of the road surface is further detected by the slope sensor 55, and an accelerator opening signal P1, which corresponds to the amount of depression of the accelerator pedal 23, is detected by the slope sensor 55.
Brake activation signal P3 obtained when the brake pedal 25 is depressed, shift lever 27
A shift lever position signal P7 corresponding to the position of and a slope signal P9 corresponding to the road surface slope are
Each is input to the electronic control circuit section 22.

Then, various control signals S1, S2, S3, S4, S5, and S6 are sent out from the electronic control circuit section 22 based on the signals P1 to P9 obtained and input from each sensor.

FIG. 3 shows the above-mentioned clutch 7, switching gear train 8,
1 schematically shows an example of a control device for a vehicle power train according to the present invention, which includes a continuously variable transmission 9, an electronic control circuit section 22, and the like.

Here, the various control signals S1 to S6 from the electronic control circuit section 22 are such that the clutch connection control signal S1 excites the connection solenoid 30 of the clutch control valve 29, and the clutch disconnection control signal S2 excites the connection solenoid 30 of the clutch control valve 29. In order to energize the cutoff solenoid 31, a shift up control signal S3 is sent to the speed change control valve 3.
A shift down control signal S4 is used to energize the speed increasing solenoid 33 of No. 2 with a predetermined duty, and a line pressure control signal S4 is used to energize the deceleration solenoid 34 of the speed change control valve 32 with a predetermined duty.
5 in order to operate the line pressure control valve 37 as described below, and the throttle control signal S
6 operates the throttle actuator 4 to adjust the opening degree of the throttle valve 3.
It is assumed that each will be supplied.

The clutch actuator 41, the continuously variable transmission 9, and the shift actuator 44 are connected to the clutch control valve 29, the shift control valve 32, and the shift lever 27 by the driver's manual operation. Hydraulic oil is sucked from the oil tank through the filter 35 and discharged by the oil pump 36 through the shift control valve 43 which is controlled by being switched to N, drive D, and low L shift positions. It is supplied through each oil channel.

The continuously variable transmission that is controlled by being supplied with hydraulic oil in this manner is configured to be able to transmit the output of the engine 1 to the drive wheels 12 and perform related control as described below. ing.

That is, the rotation of the output shaft 6 of the engine 1 is first
A flywheel 38 provided at the end of the output shaft 6
It is transmitted to a clutch 7 which is continuously press-connected to the output shaft 6 and rotates coaxially with the output shaft 6. This clutch 7 has a friction plate 39 that presses against the flywheel 38, and a diaphragm-shaped clutch spring 40 to which a pressure plate that presses the friction plate 39 is fixed, and the clutch connection control signal S1 is transmitted to the clutch control valve. 29, the connection solenoid 30 is energized and turned on, thereby supplying hydraulic oil from the open port to the clutch actuator 41, inside which the piston is moved by the elasticity of the spring. , and rotates the lever 42 counterclockwise. As a result, the clutch spring 40 in the open state is moved to the closed state and presses the friction plate 39, thereby bringing the clutch 7 into the connected state. As a result, the rotation of the output shaft 6 of the engine 1 is transmitted to the output side of the clutch 7.

Further, when the clutch cutoff control signal S2 is sent to the cutoff solenoid 31 of the clutch control valve 29, the cutoff solenoid 31 is energized and turned on, and the hydraulic oil is discharged from the clutch actuator 41 and the internal The piston is returned by the elasticity of the spring, and the clutch spring 40 becomes open. As a result, the friction plate 39
The pressing state against the flywheel 38 is released, and the clutch 7 is brought into the disengaged state. In this state, the rotation of the output shaft 6 of the engine 1 is controlled by the clutch 7.
is not transmitted to the output side.

Further, a clutch connection control signal S1 and a clutch disconnection control signal S2 are sent to the connection solenoid 30 and cutoff solenoid 31 of the clutch control valve 29.
When neither is delivered, the open port of the clutch control valve 29 is closed and the piston in the clutch actuator 41 is maintained in its immediately previous position, thus causing the flywheel 3 of the friction plate 39 to close.
The pressed state for 8 is maintained.

On the output side of the clutch 7 that operates in this way,
To the input shaft 16 of the continuously variable transmission 9, the shift lever 27
A switching gear train 8 is provided so that the rotation of the output shaft 6 of the engine 1 is transmitted according to each of the above-mentioned shift positions. In this switching gear train 8, when the shift lever 27 is positioned in drive D or low L, the piston of the shift actuator 44 moves in the direction D in the figure, and A gear 46 provided on the input shaft 16 of the continuously variable transmission 9 engages with the gear 45 to rotate the input shaft 16 of the continuously variable transmission 9 in the opposite direction to the output shaft 14 of the clutch 7. On the other hand, the shift lever 27
When is placed in the reverse R position, the piston of the shift actuator 44 moves in the R direction in the figure, and the gear 47 provided on the input shaft 16 of the continuously variable transmission 9 is fixed to the output shaft 14 of the clutch 7. It engages with the idle gear 49 that is engaged with the reverse gear 48 that has been moved,
The input shaft 16 of the continuously variable transmission 9 is moved in the opposite direction to that of the drive D described above, that is, the output shaft 1 of the clutch 7
Rotate in the same direction as 4. Further, when the shift lever 27 is placed in the neutral N position, the piston of the shift actuator 44 is held in the center of the cylinder, and the output shaft 1 of the clutch 7 is held in the center of the cylinder.
4 is prevented from being transmitted to the input shaft 16 of the continuously variable transmission 9.

The continuously variable transmission 9 to which the rotation of the output shaft 14 of the clutch 7 is transmitted includes an input shaft 16 that rotates coaxially with the output shaft of the switching gear train 8, and a drive that rotates integrally with the input shaft 16. It has a pulley 50, a driven pulley 52 to which rotation of the drive pulley 50 is transmitted via a V-belt 51, and an output shaft 10 that rotates integrally with the driven pulley 52.

The drive pulley 50 has a movable conical plate 50a and a fixed conical plate 50b.
0a and the fixed conical plate 50b have their conical surfaces facing each other to form a V-shaped pulley groove. A cylinder chamber 50c is provided behind the movable conical plate 50a.
Fixed conical plate 50b depending on the supply state of hydraulic oil to
The fixed conical plate 50b is axially slidable toward or away from the input shaft 16. The fixed conical plate 50b is fixed to the input shaft 16. On the other hand, the driven pulley 52 has the same configuration as the driving pulley 50 described above, and has a V-shaped pulley groove formed by a movable conical plate 52a and a fixed conical plate 52b. Depending on the state of supply of working pressure oil to the cylinder chamber 52c, the fixed conical plate 52b can be slid in the axial direction so as to be close to the fixed conical plate 52b.
2b is fixed to the output shaft 10.

A V-belt 51 is stretched over each of the pulley grooves formed in the drive pulley 50 and the driven pulley 52, thereby transmitting the rotation of the drive pulley 50 to the driven pulley 52. And drive pulley 5
When transmitting zero rotation to the driven pulley 52, the V-belt 5 determined by the width of the pulley groove of the drive pulley 50
The V-belt 51 is determined by the rotation radius on the driving pulley 50 side of 1 and the width of the pulley groove of the driven pulley 52.
By changing the rotation radius on the driven pulley 52 side, the rotation ratio between the driving pulley 50 and the driven pulley 52 can be changed.

The width of each pulley groove of the driving pulley 50 and the driven pulley 52 is changed by sliding the respective movable conical plates 50a and 52 in the axial direction,
Such sliding control of the movable conical plates 50 and 52 is performed by the speed change control valve 32 which receives the shift up control signal S3 and the shift down control signal S4 from the electronic control circuit section 22 described above. That is, when the shift-up control signal S3 from the electronic control circuit unit 22 is supplied to the speed-up solenoid 33 of the speed change control valve 32, the speed-up solenoid 33 is intermittently energized and turned on and off, thereby Working pressure oil is supplied to the cylinder chamber 50c of the driving pulley 50 and removed from the cylinder chamber 52c of the driven pulley 52 in accordance with the control duty of the shift-up control signal S3, while the shift-down control signal S4 decelerates. When supplied to the solenoid 34, the deceleration solenoid 34 is intermittently energized and turned on and off, thereby
Working pressure oil is supplied to the cylinder chamber 52c of the driven pulley 52 and removed from the cylinder chamber 50c of the drive pulley 50 in accordance with the control duty of the downshift control signal S4. Further, when both the speed increase solenoid 33 and the deceleration solenoid 34 are turned off, the cylinder chambers 50c and 5 of the drive pulley 50 and the driven pulley 52 are
The supply and removal of hydraulic oil to and from 2c is stopped.

Therefore, when the speed increase solenoid 33 is turned on or off by the shift-up control signal S3, the movable conical plate 50a is moved in a direction approaching the fixed conical plate 50b, and the movable conical plate 50 and the fixed conical plate The width of the pulley groove formed by the plate 50b is reduced, and the rotation radius of the V-belt 51 on the drive pulley 50 side is increased. Also, at the same time,
The movable conical plate 52a is moved in a direction away from the fixed conical plate 52b, and the width of the pulley groove formed by the movable conical plate 52a and the fixed conical plate 52b is expanded, and the width of the pulley groove on the driven pulley 52 side of the V-belt 51 is increased. The turning radius is reduced. Therefore, the gear ratio in the continuously variable transmission 9 becomes small. On the other hand, when the deceleration solenoid 34 is turned on/off by the downshift control signal S4, the width of the pulley groove of the drive pulley 50 is expanded, and the width of the drive pulley 50 of the V-belt 51 is increased. The radius of rotation on the side is reduced, and at the same time the driven pulley 5
The width of the second pulley groove is reduced, and the rotation radius of the V-belt 51 on the driven pulley 52 side is expanded. Therefore, in this case, the gear ratio of the continuously variable transmission 9 is increased. Further, a shift-up control signal S3 and a shift-down control signal S4 are applied to the speed increase solenoid 33 and the deceleration solenoid 34.
If none of the solenoids are delivered and each solenoid is turned off, the width of the pulley groove of each of the driving pulley 50 and the driven pulley 52 is maintained unchanged, and therefore the width of the V-belt 51 is maintained unchanged. The respective rotation radii on the drive pulley 50 side and the driven pulley 52 side are maintained, and the gear ratio in the continuously variable transmission 9 is adjusted to the speed increase solenoid 33 and the deceleration solenoid 3.
4 is kept at the state immediately before it was turned off.

In this way, the continuously variable transmission is capable of continuously changing the gear ratio by changing the supply state of the working pressure oil to the cylinder chambers 50c and 52 of the driving pulley 50 side and the driven pulley 52, respectively. 9, the greater the required traveling driving force, the greater the movable conical plate 50a relative to the V-belt 51.
It is necessary to increase the belt transmission force (transmission torque capacity of the V-belt 51) by the V-belt 51 by increasing the pressing force of the V-belt 51 and 52. Therefore, in this example, the oil pressure of the working pressure oil supplied from the oil pump 36 to the cylinder chamber 50c or 52c via the speed change control valve 32, that is, the line pressure, is determined by the line pressure control signal from the electronic control circuit section 22. It is adapted to be regulated by a line pressure control valve 37 receiving S5. That is, the line pressure control valve 37 is configured to be able to change the amount of oil that passes through it and is discharged, depending on the level of the line pressure control signal S5 supplied to the solenoid 37a, for example. In this case, the line pressure control signal S
The higher the level of 5, the lower the amount of oil discharged and the higher the line pressure.

As described above, in an example of the vehicle power train control device according to the present invention, when the vehicle accelerates,
From the change in the accelerator opening α detected by the accelerator opening detection sensor 24, it is detected that the accelerator pedal 23 has been depressed for acceleration. Then, the electronic control circuit unit 22 controls the accelerator opening α
Based on the change α′, the vehicle acceleration to be obtained at that time is set as the target vehicle acceleration G _T ,
This target vehicle acceleration G _T is the accelerator pedal 23
Engine speed Ne and throttle valve opening that can be obtained continuously during the period when the pedal is depressed for acceleration and with minimum fuel consumption.
Th is set as the target engine speed TNe and the target throttle valve opening TTh, respectively. Then, the shift-up control signal S3 or the shift-down control signal S4 is supplied to the speed change control valve 32 to control the gear ratio of the continuously variable transmission 9 so that the target engine speed TNe is obtained, and the gear ratio of the continuously variable transmission 9 is controlled. A throttle control signal S6 is supplied to the throttle actuator 4 to control the throttle valve 3 so as to obtain the target throttle valve opening TTh.

In this case, while the vehicle is running, the accelerator pedal 23 is depressed and the vehicle enters an acceleration state. For example, in FIG. 4, the horizontal axis represents the vehicle speed V, and the vertical axis represents the driving force Fe. In characteristics, curve
Assuming that point d ₁ on F ₁ moves to point d ₂ on curve F ₂ , the acceleration corresponding to the difference in driving force between this point d ₂ and point d ₁ is the target vehicle acceleration G _T. Ru. These points d ₁ and d ₂ , the accelerator opening α, and the accelerator opening α when the accelerator pedal is depressed for acceleration
This can be determined from the change α' and the output shaft rotational speed _N0 of the continuously variable transmission 9, which represents the vehicle speed V. In order to maintain this target vehicle acceleration G _T continuously until the acceleration state of the vehicle is released and the vehicle returns to point d ₄ on curve F ₁ , the traveling driving force characteristic curve passing through point d ₂ must be maintained. It is necessary to transport on F ₂ to point d ₃ corresponding to point d ₄ . For this, engine 1
is the engine output ω ₁ →ω 2 →ω ₃ → according to the running drive characteristic curve W with the engine output that crosses between point d ₂ and point _{d 3} on curve F ₂ as a parameter.
It is required to change it sequentially from ω ₄ to ω ₅ . In this example, the engine speed is adjusted so that the engine output changes from ω ₁ → ω ₂ → ω ₃ → ω ₄ → ω ₅ with the minimum fuel consumption.
Ne and throttle valve opening Th are controlled.

By the way, as shown in Fig. 5, the horizontal axis represents the engine speed Ne, and the vertical axis represents the engine torque T.
There is an optimal fuel consumption zone Z in the power source characteristics of the engine 1, which is shown by taking Engine speed at points e ₁ , e ₂ , e ₃ , e ₄ , e ₅ crossed by engine outputs ω ₁ , ω ₂ , ω ₃ , ω ₄ , ω ₅
Ne ₁ , Ne ₂ , Ne ₃ , Ne ₄ , and Ne ₅ are each set as the target engine speed TNe, and the power source characteristic curve TH with the throttle valve opening Th as a parameter
Throttle valve openings Th ₁ , Th ₂ , Th ₃ , Th ₄ , Th ₅ of those passing through points e ₁ , e ₂ , e ₃ , e ₄ , e ₅
are each assumed to be the target throttle valve opening TTh.
Then, the shift-up control signal S3 and the shift-down control signal S4 from the electronic control circuit section 22 are
The speed increasing solenoid 3 of the speed change control valve 32 in a predetermined manner
3 and reduction solenoid 34, thereby controlling the gear ratio of the continuously variable transmission 9 such that the target engine speed TNe is successively achieved, and the throttle control signal S6 from the electronic control circuit section 22. is supplied to the throttle actuator 4 in a predetermined manner, and the opening degree of the throttle valve 3 is controlled so that the above-mentioned target throttle valve opening degree TTh is successively achieved. As a result, when the vehicle accelerates, the engine 1 is in a target fuel consumption state and its engine output changes sequentially from ω ₁ → ω ₂ → ω ₃ → ω ₄ → ω ₅ , and as a result, the accelerator pedal 2
During the period in which the driver is depressing the vehicle for acceleration, the set target vehicle acceleration G _T will continue to be obtained in the optimum fuel consumption state.

On the other hand, when the accelerator pedal 23 is released, contrary to the acceleration when the accelerator pedal 23 is depressed as described above, the shift lever 27 is detected by the shift lever position detection sensor 28. If the position is drive range D, the aforementioned target vehicle acceleration G _T is newly set to 0 in order to achieve a constant speed driving state in which the vehicle speed at the start of the return operation of the accelerator pedal 23 is continuously maintained. be done so that it may be accomplished.

Therefore, when the accelerator pedal 23 is released, the target vehicle acceleration is set to 0.
Achieve G _T , i.e. reduce the actual vehicle acceleration G to 0
The engine speed Ne and throttle valve opening Th to achieve the target engine speed are respectively
TNe and target throttle valve opening TTh are set respectively, and the target engine rotation speed TNe
A shift up control signal S3 and a shift down control signal S4 are supplied to the speed change control valve 32 to control the gear ratio of the continuously variable transmission 9 so as to obtain the target throttle valve opening.
A throttle control signal S6 is supplied to the throttle actuator 4 to control the throttle valve opening Th so as to obtain TTh.

In this case, the curve F ₂ in FIG.
Assuming that the accelerator pedal 23 is released when the vehicle speed corresponding to point d ₃ above is obtained, it is necessary to move from point d ₃ on curve F ₂ to point d ₄ on curve F ₁ . Become. For this, engine 1
is a running drive characteristic curve W with the engine output as a parameter crossing between points d ₃ and d ₄ on curve F ₂
Accordingly, it is required to change the output sequentially from ω ₅ to ω ₃ .

The engine rotational speed Ne and the throttle valve opening Th are controlled so that such changes in engine output can be achieved with minimum fuel consumption. That is, in the above-mentioned FIG. 5, the engine speed Ne _{5 and the throttle valve at the point e 5 where zone Z is crossed by the power source characteristic curve W' whose engine output is ω 5 with the} engine output as a parameter. The opening Th ₄ is at the time when the return operation of the accelerator pedal 23 is started, and from this engine rotation speed Ne ₅ and the throttle valve opening Th ₅ ,
The engine speed Ne 4 and the engine speed Ne ₄ and the throttle opening Th 3 are adjusted along the zone Z in order to reach the engine speed Ne ₃ and the throttle opening Th ₃ at the point e ₃ where the engine output is ω ₃ of the power source characteristic curve W′ intersects, respectively. The target engine speed TNe and the target throttle valve opening TTh are sequentially set so that the target engine speed TNe and the target throttle valve opening TTh are decreased through the throttle opening Th ₄ , and these target engine speed TNe and target throttle valve opening TTh are achieved. The gear ratio control of the continuously variable transmission 9 and the target throttle valve opening Th are controlled in this manner.

As a result, when the accelerator pedal 23 is returned while the shift lever 27 is in the drive range D, the output of the engine 1 changes in the optimum fuel consumption state, and the actual vehicle acceleration G becomes 0. As a result, the vehicle is brought into a constant speed running state in which the vehicle speed at the time when the return operation of the accelerator pedal 23 is started is maintained.

The state of change from the constant acceleration running state to the constant vehicle speed running state as described above is shown in FIG. 6B is a graph in which the vertical axis represents the vehicle speed V and the horizontal axis represents time. Here, a case in which the amount of depression of the accelerator pedal 23, and therefore the amount of change in the accelerator opening degree α, is large is shown by a solid line in FIG. 6A, and the corresponding change in vehicle speed V is shown in FIG. 6B. In addition, a case where the amount of depression of the accelerator pedal 23, and thus the amount of change in the accelerator opening degree α, is small is shown by a chain line in FIG. 6A, and the corresponding change in vehicle speed V is shown in FIG. 6A. is shown in dashed lines in FIG. 6B. As is clear from these graphs, the time t ₀ when the accelerator pedal 23 starts to be depressed
The period from t 1 to the time point t ₁ when the pedal enters the holding state after depressing.
Assuming that t ₀ to _{t 1} are the same, the accelerator pedal 2
When the amount of change in 3 is large, the target vehicle acceleration G _T is larger than when it is small, and therefore the vehicle speed V increases quickly. During the period t 0 to t ₂ from time t ₀ when the operation starts, through time t ₁ when the accelerator pedal 23 enters the holding state, to time _{t 2} when the return operation of the accelerator pedal 23 starts, constant acceleration continues. As a result, the vehicle speed V continues to increase. When the amount of change in the accelerator pedal 23 is large, the increase in vehicle speed at time t ₂ is larger than when it is small, and the amount of change in the accelerator pedal 23 is larger at time t ₂ .
3 is performed, from then on, the time t ₂
The vehicle speed at is maintained, and a constant vehicle speed running state is assumed.

A series of controls during acceleration of the vehicle as described above are performed based on the operation of the CPU 20 of the electronic control circuit section 22, and examples of programs executed by the CPU 20 are shown in FIGS. 7, 8, and 9. Diagram A
This will be explained with reference to the flowcharts of and B.

First, as shown in FIG. 7, after the start, initial settings are made for each part in process 60, and then in process 61, data obtained based on the signals obtained from each sensor are inputted, and the process proceeds to process 62. , a program for clutch control is executed in process 62, followed by a program for speed ratio and throttle valve opening control in process 63, and the process returns to process 61.

An example of a program for clutch control executed in the above process 62 is as shown in FIG. Here, after the start, at day 70, the shift lever is currently 2.
7 is in the neutral range (N range) position, and if the shift lever 27 is in the neutral range position, in process 71. The vehicle speed flag is reset, and in the subsequent process 72, a clutch cutoff control signal S2 is sent to the cutoff solenoid 31 of the clutch control valve 29, and the cutoff solenoid 31 is turned on and the connection solenoid 3 is turned on.
0 is the off state. As a result, clutch 7
is considered to be in a cut-off state.

If decision 70 determines that the shift lever 27 is not in the neutral range position, decision 73 determines that the current vehicle speed V is greater than a preset predetermined vehicle speed Va. Determine whether or not. Here, vehicle speed Va
is set to a vehicle speed at which there is a high risk of engine stoppage, and if it is determined that the vehicle speed V is greater than the vehicle speed Va, the following process 74 is performed.
Set the vehicle speed flag and proceed to decision 75.

In decision 75, engine speed
It is determined whether the change Ne′ in Ne is positive or negative, and if the change Ne′ in engine speed Ne is positive, decision 76 determines that the engine speed Ne is greater than the clutch output shaft speed Nc. Determine whether or not.
If it is determined that the engine speed Ne is greater than the clutch output shaft speed Nc, process 77
A clutch connection control signal S1 is sent to the connection solenoid 30 of the clutch control valve 29, turning the connection solenoid 30 on and turning the cutoff solenoid 31 off. As a result, clutch 7
The friction plate 39 is made to press against the flywheel 38, and the transmission torque capacity of the clutch 7 gradually increases. If it is determined at decision 76 that the engine speed Ne is smaller than the clutch output shaft speed Nc, the process proceeds to process 79, where both the clutch connection control signal S1 and the clutch disconnection control signal S2 are It is prevented from being delivered and both the connection solenoid 30 and the cutoff solenoid 31 are turned off. This causes the flywheel 3 of the friction plate 39 of the clutch 7 to
8 is maintained at its current state, and therefore the transmission torque capacity of clutch 7 is maintained at its current state.

On the other hand, if it is determined at decision 75 that the amount of change Ne' in the engine speed Ne is negative, the process proceeds to decision 78, where it is determined whether the engine speed Ne is smaller than the clutch output shaft speed Nc. If the engine speed Ne is smaller than the clutch output shaft speed Nc,
Proceed to process 77. As a result, the transmission torque capacity of the clutch 7 gradually increases as described above. If it is determined at decision 78 that the engine speed Ne is not smaller than the clutch output shaft speed Nc, the process proceeds to process 79 where the connection solenoid 30 and the cutoff solenoid 31 are activated as described above.
Both are turned off.

If it is determined in decision 73 that the current predetermined vehicle speed V is not greater than the vehicle speed Va,
Proceeding to decision 80, it is determined whether the accelerator pedal 23 is on, that is, whether the accelerator pedal 23 is depressed, and the accelerator pedal 23 is turned on.
If it is determined that the switch 3 is in the on state, the process proceeds to decision 75, and the process proceeds as described above.

On the other hand, the accelerator pedal is 23 at decision 80.
If it is determined that the vehicle speed flag is not in the on state, decision 81 determines whether the vehicle speed flag is in the set state. If the vehicle speed flag is in the set state, decision 82 determines whether the brake pedal 25 is in the on state or not. That is, it is determined whether or not the brake pedal 25 is depressed, and if it is determined that the brake pedal 25 is in the on state, the process advances to decision 83. If it is determined at decision 81 that the vehicle speed flag is not set, the process proceeds to process 72, in which the cutoff solenoid 31 is turned on and the connection solenoid 30 is turned off, as described above.

Then, in decision 83, it is determined whether or not the engine speed Ne is less than a predetermined value, for example 1500 rpm. Here, engine speed
1500 rpm is a rotation speed that may cause the engine to stop when the brake pedal 25 is on.If the engine rotation speed Ne is not 1500 rpm or less, the process proceeds to decision 75, and the flow continues as described above. move on. If the engine speed Ne is 1500 rpm or less, the process proceeds to process 71, and the process proceeds as described above.

If the decision 82 determines that the brake pedal 25 is not in the on state, the process proceeds to a decision 84, where it is determined whether the engine speed Ne is below a predetermined value, for example 1000 rpm. Here, engine speed
1000 rpm is the rotation speed that may cause the engine to stop when the brake pedal 25 is in the OFF state, and if the engine rotation speed Ne is not below 1000 rpm, the process proceeds to decision 75, and the flow as described above is followed. Proceed with On the other hand, if the engine speed Ne is 1000 rpm or less, the process proceeds to process 71, and the process proceeds as described above.

Next, an example of the program for controlling the gear ratio and throttle valve opening degree executed in the process 63 of the program shown in FIG.
As shown in Figures A and B. Here, first, as shown in FIG. 9A, after the start, the accelerator opening signal P1 is output at decision 101.
The change status of the accelerator opening α is determined based on
If it is determined that the accelerator opening degree α has increased, the process proceeds to process 102, and if it is determined that the accelerator opening degree α has not changed, the process proceeds to decision 103.

Then, in process 102, which is proceeded when it is determined that the accelerator opening degree α has increased, a shift flag indicating an acceleration request is set, and the process proceeds to process 104. On the other hand, in decision 103, which is proceeded when it is determined that the accelerator opening degree α has not changed, it is determined whether or not the shift flag is in the set state, and if it is determined that it is in the set state, the step is proceeded to process 104. . In the process 104, the change α' is obtained from the accelerator opening α used in the decision 101, and based on this change α', the change α' and the target vehicle acceleration G _T as shown in FIG. The target vehicle acceleration G _T is set from the map representing the correspondence relationship between the two. In the subsequent process 105, the actual vehicle speed V _C at that time is read as the vehicle speed V, and in the subsequent process 106, the road surface slope K obtained from the slope signal P9 and the actual vehicle speed read in the process 105 are used.
Based on V _C , the running resistance F _L of the vehicle at that time is calculated. Note that this running resistance F _L is the slope resistance
_RK is calculated from rolling resistance Rr and air resistance Ri.

Subsequently, as shown in FIG. 9B, process 1
Proceeding to step 07, the traveling driving force Fe for achieving the target vehicle acceleration G _T set in process 104 is determined.
It is calculated by adding the acceleration resistance Ra to the running resistance F _L obtained in process 106. and,
In the subsequent process 108, the engine output Pe required to achieve the traveling driving force Fe calculated in the process 107 with the minimum fuel consumption, that is,
The engine outputs ω ₁ , ω ₂ , ω ₃ , ω ₄ , ω ₅ as shown in FIG.
Proceed to. In the process 109, the process 1 is started at points e ₁ , e ₂ , e ₃ , e ₄ , e ₅ as shown in FIG.
It is required to generate the engine output Pe calculated in 08. The target engine speed TNe as shown by the engine speeds Ne ₁ , Ne ₂ , Ne ₃ , Ne ₄ , Ne ₅ in FIG.
In the figure, the throttle valve openings Th ₁ , Th ₂ ,
The target throttle valve opening degree TTh as shown by Th ₃ , Th ₄ , and Th ₅ is calculated.

Then, in decision 110, it is determined whether the actual engine speed Ne at that time is higher than the target engine speed TNe calculated in process 109. As a result of this judgment, if the actual engine speed Ne is higher than the target engine speed TNe, in process 111, a shift up control signal S
3 to the speed increasing solenoid 33 of the speed change control valve 32 to turn the speed increasing solenoid 33 on and off,
The deceleration solenoid 34 is turned off. As a result, the gear ratio in the continuously variable transmission 9 is reduced, and as a result, the input shaft rotational speed Np of the continuously variable transmission 9 is reduced.At this time, since the clutch 7 is in the connected state, the engine rotational speed Ne is also lowered.

On the other hand, as a result of the determination in decision 110, if the engine speed Ne is lower than the target engine speed TNe, in process 112, the speed change control valve 3
A shift down control signal S4 is sent to the second deceleration solenoid 34 to turn the deceleration solenoid 34 on and off, and the speed increase solenoid 33 is turned off. As a result, the gear ratio in the continuously variable transmission 9 is increased, and as a result, the input shaft rotation speed of the continuously variable transmission 9 is increased.
Np, and therefore the engine speed Ne, is increased. In this way, by the operation of process 111 or 112, the actual engine speed Ne
also match the target engine speed TNe.

Next, the process advances to density 113, and the actual throttle valve opening Th at that time is determined in process 10.
Target throttle valve opening TTh calculated in 9
If it is larger, a throttle control signal S6 for reducing the throttle valve opening is sent to the throttle actuator 4 in process 114, and the throttle valve opening is changed. If Th is reduced, and if it is small,
In process 115, a throttle control signal S6 for increasing the throttle valve opening is sent to the throttle actuator 4 to increase the throttle valve opening Th.
increase. The operation of process 114 or 115 causes the actual throttle valve opening Th to match the target throttle valve opening TTh.

In this way, in the flow from decision 101 to process 115, the gear ratio n and throttle valve opening Th are adjusted to obtain a predetermined target vehicle acceleration G _T with minimum fuel consumption while the accelerator is being depressed or during the subsequent depression holding period. Control is exercised.

On the other hand, if it is determined that the accelerator opening degree α is decreasing at decision 101 shown in FIG. The vehicle speed flag indicating that driving is requested is reset, and then, in the case where it is determined that the shift flag is not in the set state at decision 103 described above, decision 118 is executed.
Proceed to. In the decision 118, it is determined whether or not the position of the shift lever 27 determined from the shift lever position signal P7 is in the low range (L range). range), it is determined at the subsequent decision 119 whether or not the vehicle speed flag is set. Here, if it is determined that the vehicle speed flag is not set, the process proceeds to process 120, where the actual vehicle speed V _C at that time is read as the vehicle speed V, similar to process 105 described above, and the vehicle speed flag is set in the subsequent process 121. Then proceed to process 122. On the other hand, if it is determined in decision 119 that the vehicle speed flag is in the set state, the process directly proceeds to process 122.
Then, in process 122, the target vehicle acceleration G _T is set to 0, and the process proceeds to process 106.
are executed sequentially. In this case, the target vehicle acceleration G _T is set to 0, so the acceleration resistance Ra is set to 0, and the vehicle running driving force Fe calculated in process 107
becomes equal to running resistance F _L , the vehicle runs at a constant speed, and the optimum fuel consumption state is maintained even when running at this constant speed.

Further, if it is determined in decision 118 that the vehicle is in the low range L, the process proceeds to process 123, where a target gear ratio n _T corresponding to the vehicle speed V is set. Next, the process proceeds to decision 124, where the ratio Np/Ns of the input shaft rotational speed Np to the output shaft rotational speed Ns at that time, that is, the actual gear ratio n at that time is set to the target gear ratio n set in the process 123. _T
If it is larger, the process proceeds to process 125 and sends a shift up control signal S3 to the speed increase solenoid 33 in order to make the gear ratio n smaller; If so, the process proceeds to process 126, where a downshift control signal S4 is sent to the deceleration solenoid 34 to increase the gear ratio n, thereby controlling the gear ratio.

Then, in the subsequent process 127, a throttle control signal S6 is supplied to the throttle actuator 4 in a predetermined manner in order to decrease the throttle valve opening Th, and the throttle actuator 4 is operated in the closing direction.

In this way, processes 123 to 127
, a target gear ratio n _T is set according to the vehicle speed V, and gear ratio control is performed to achieve this target gear ratio n _T , so that effective engine braking is applied to the vehicle and deceleration is achieved. It's done smoothly.

(Effects of the Invention) As is clear from the above description, according to the vehicle power train control device according to the present invention, the output of the vehicle engine is efficiently transmitted to the driven part of the vehicle through the continuously variable transmission mechanism. In addition, when an operation is performed that increases the amount of operation of the required engine output setting means, such as pressing an accelerator pedal, the operation state of the required engine output setting means and the subsequent holding state As the running resistance increases due to the increase in vehicle speed, the running driving force increases, and since this increase in running driving force is obtained under the optimum fuel consumption condition, the operation amount of the required engine output setting means increases. If a constant vehicle acceleration corresponding to the required engine output is continuously achieved with minimum fuel consumption, and on the other hand, an operation is performed that causes the amount of operation of the required engine output setting means to be decreased, such as a release operation of the accelerator pedal. In the operation state of the required engine output setting means and the subsequent holding state, the vehicle speed at the time when the operation of the required engine output setting means is started is continuously maintained with the minimum fuel consumption amount. Therefore, the vehicle power train control device according to the present invention can provide the driver of the vehicle in which the device is installed with a sufficient feeling of acceleration during acceleration under optimal fuel consumption conditions, and The vehicle can run at a stable constant speed after acceleration.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of a vehicle power train control device according to the present invention, and FIG. 2 is a schematic configuration diagram showing a drive control section of a vehicle to which an example of the vehicle power train control device according to the present invention is applied. Fig. 3 is a schematic configuration diagram showing an example of a control device for a vehicle power train according to the present invention, Fig. 4, Fig. 5, Fig. 6 A and B, and Fig. 10 are shown in Fig. 3. The characteristic diagrams shown in FIGS. 7, 8, and 9 A and B are used to explain the operation of the example shown in FIG. It's a chat. In the diagram, 1 is the engine, 3 is the throttle valve,
4 is the throttle actuator, 7 is the clutch,
9 is a continuously variable transmission mechanism, 22 is an electronic control circuit section, 23
24 is an accelerator pedal, 24 is an accelerator opening detection sensor, and 32 is a speed change control valve.

Claims (1)

[Scope of Claims] 1. A gear ratio adjusting section that changes the gear ratio of a continuously variable transmission mechanism provided in a power transmission path from the engine to the wheels of a vehicle; Engine output adjusting means that changes the load of the engine; requested engine output setting means for activating the engine output adjusting means; a detecting section for detecting an operating state of the requested engine output setting means; When the operation amount of the output setting means is to be increased, the operation of the required engine output setting means detected by the means for setting the target vehicle acceleration according to the operation, and the detection section increases the required engine output. means for setting a predetermined target vehicle speed, when the method is designed to reduce the amount of operation of the setting means;
and the speed change in order to cause the vehicle to take a constant acceleration running state where the target vehicle acceleration is continuously achieved or a constant speed running state where the target vehicle speed is continuously achieved under the optimum fuel consumption state. A control device for a vehicle power train, comprising: a control section including means for sending a control signal to a ratio adjustment section and the engine output adjustment means to change the speed ratio and the load of the engine.