JPS61132437A - Gear ratio control device in stepless speed change unit - Google Patents

Abstract

PURPOSE:To make it possible to give a satisfactory feeling of acceleration to the driver and to realize a stable constant speed travel after acceleartion, by selectively carrying out a constant acceleration travel or a constant speed travel in accordance with the increasing and decreasing condition of operating amount of an accelerator regulating means. CONSTITUTION:In an arrangement in which the gear ratio of a speed change mechanism 9 is changed by means of a gear ratio regulating section A, there is provided an accelerator operation detecting section B for detecting the operating condition of an accelerator regulating means. Further, there are provided a setting means C for setting a desired acceleration in accordance with the operating amount of the accelerator regulating means which is known from the output of the detecting means B, when the operation of the accelerator regulating means is in the direction of increasing the operating a amount, and a setting means D for setting a predetermined vehicle speed when it is in the direction of decreasing the operating amount. Further, a supply means E delivers a control signal to the regulating section A to selectively carry out a constant acceleration travel in which the desired acceleration is continuosly attained or a constant vehicle speed travel in which the desired vehicle speed is continuosly attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a gear ratio control device that controls a gear ratio in a continuously variable transmission mechanism provided in a power transmission path from an engine to drive wheels.

(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. A continuously variable transmission mechanism installed in such a vehicle is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-767.
As described in Japanese Patent No. 09, the gear ratio is controlled based on the vehicle speed or engine rotational speed and the throttle valve opening adjusted by operating an accelerator adjustment means such as an accelerator pedal.

In such a case, the gear ratio of the continuously variable transmission mechanism is usually controlled so that the engine rotation speed, and therefore the input rotation speed of the continuously variable transmission mechanism, is uniquely determined with respect to the throttle valve opening. . 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 achieve the desired speed, but the acceleration in such a case is
In order to maintain a feeling of acceleration, it is desirable to be able to continuously obtain a predetermined magnitude in response to a constant depression of the accelerator pedal, that is, a constant increase in the throttle valve opening.

However, in the case of a vehicle equipped with a continuously variable transmission mechanism as described above, the continuously variable transmission mechanism has a transmission ratio that maintains the engine speed constant for each throttle valve opening value. Since the control is performed, immediately after the accelerator pedal is depressed, the engine speed increases to a predetermined value and the engine output increases accordingly, and then the increased engine output continues. The vehicle is maintained at a constant engine output, and driving is performed 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 119% increase in running resistance due to the increase in vehicle speed,
Since the engine output is maintained constant, even if the driver continues to press the accelerator pedal at a constant rate, the driving force of the vehicle decreases and 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 noticeably and the driver does not have any audible complaints. You will feel it.

Therefore, in order to solve the above-mentioned problems, the applicant has
Previously, in Japanese Patent Application No. 58-205043, a target vehicle acceleration is set according to the operation of an accelerator adjustment means such as an accelerator pedal, and a continuously variable transmission mechanism is used to continuously achieve the set target vehicle acceleration. We proposed an electronically controlled continuously variable transmission that controls the gear ratio. This way,
According to the electronically controlled continuously variable transmission, during the acceleration period, the driving force increases as the running resistance increases due to the increase in vehicle speed, and as a result, the vehicle equipped with this electronically controlled continuously variable transmission increases. It is possible to provide the driver with a sufficiently satisfying feeling of acceleration when stepping on the accelerator for acceleration.

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 commensurate with 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 vehicles equipped with the above-mentioned continuously variable transmission mechanism,
In the accelerator pedal depression operation (acceleration operation) state and the subsequent holding state, the vehicle is accelerated according to the accelerator pedal depression operation at that time, and in the accelerator pedal return operation state and the subsequent holding state, It is desirable that acceleration be stopped and the vehicle be allowed to travel at a constant speed.

(Object of the Invention) In view of the above, the present invention provides that, in a state in which an operation to increase the amount of operation of the accelerator adjustment means is performed, such as an operation to press the accelerator pedal, and in a subsequent holding state, the accelerator adjustment at that time is In a state in which a constant vehicle acceleration corresponding to the operation of the means is continuously achieved, and an operation is performed to reduce the amount of operation of the accelerator adjustment means, such as a return operation of the accelerator pedal, and in a subsequent holding state, An object of the present invention is to provide a gear ratio control device for a continuously variable transmission that controls the gear ratio of a continuously variable transmission mechanism arranged in a driving force transmission path of a vehicle in order to maintain a constant vehicle speed.

(Structure of the Invention) The gear ratio control device for a continuously variable transmission according to the present invention has a basic structure as shown in FIG. A gear ratio adjustment section that changes the gear ratio of the mechanism, an accelerator operation detection section that detects the operating state of an accelerator adjustment means that changes the engine load, such as an accelerator pedal, and a shift 1/hi adjustment section that controls and disables the transmission. and a gear ratio control section that causes a change in the gear ratio of the step-change transmission mechanism, and the gear ratio control section detects that the operation of the accelerator adjustment means detected by the accelerator operation detection section is similar to the depression operation of the accelerator pedal. , when the operation amount of the accelerator adjustment means is to be increased, the target vehicle acceleration setting means sets the target vehicle acceleration according to this operation, and the operation of the accelerator adjustment means detected by the accelerator operation detection section as well. is intended to reduce the amount of operation of the accelerator adjustment means, such as a return operation of the accelerator pedal, the target vehicle speed setting means sets a predetermined target vehicle speed, and the vehicle continues to have the above-mentioned target vehicle acceleration. control signal supply means for sending a control signal to the gear ratio adjustment section in order to selectively cause a constant acceleration running state in which the two target vehicle speeds are continuously achieved or a constant vehicle speed running state in which two target vehicle speeds are continuously achieved; shall be included.

With this configuration, it is possible to cause the vehicle to take a constant acceleration running state and a constant speed running state desired by the driver in accordance with the control operation of the accelerator adjustment means by the driver of the vehicle.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an outline of a drive control section of a vehicle to which an example of the gear ratio control device for a continuously variable transmission 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 a throttle actuator 4
The throttle position sensor 5 detects the opening degree. Note that the bundled portion of the intake passage 2 on the downstream side of the throttle valve 3 is connected to the branch passage 2.
a, 2b, 2c, and 2d to communicate with each cylinder, and each of these branch paths 2a.

Fuel injection valves (not shown) are provided at 2b, 2c, and 2d.

The 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 the output shaft 10 of this continuously variable transmission 9 is connected to drive wheels 12 via a differential gear 11. There is.

Further, an engine rotation speed detection sensor 3. detects the rotation speed of the output shaft 6 of the engine 1. Clutch output shaft rotation speed detection sensor for detecting the rotation speed of the output shaft 14 of the clutch 7 5.
A transmission input shaft rotation speed detection sensor 17 that detects the rotation speed of the input shaft 16 of the continuously variable transmission 9. Further, transmission output shaft rotation speed detection sensors 18 for detecting the rotation speed of the output shaft 1o of the continuously variable transmission ia9, and therefore the vehicle speed, are installed at predetermined positions. Then, the throttle position signal P5. from the aforementioned throttle position sensor 5 is sent. Engine speed signal P2 from the engine speed detection sensor 3 mentioned above
．． Clutch output shaft rotation speed signal P4 from the clutch output shaft rotation speed detection sensor 15, transmission input shaft rotation speed signal P6 from the transmission input shaft rotation speed detection sensor 7, gear change from the transmission output shaft rotation speed detection sensor 8 Machine output shaft rotation speed signal P
8 are input to an electronic control circuit unit 22 that includes an interface unit 19, a CPU 20, and a memory 21 as main components.

Specifically, the amount of depression of the accelerator pedal 23 operated by the driver, that is, the accelerator opening degree, is detected by the accelerator opening detection sensor 24, the depression state of the brake pedal 25 is detected by the brake operation detection sensor 26, and ,
The shift position of the shift lever 27 is detected by the shift lever position detection sensor 28, and the gradient of the road surface is detected by the gradient sensor 55, and an accelerator opening signal P1° corresponding to the amount of depression of the accelerator pedal 23 and the brake pedal 25 are detected. The brake activation signal P3. is obtained when P3. A shift lever position signal P7 corresponding to the position of the shift lever 27 and a gradient signal P9 corresponding to the road surface gradient are input to the electronic control circuit section 22, respectively.

Then, the electronic control circuit unit 22 outputs various control signals SL, 32 . S3. S4-, S5 and S6 are sent out.

FIG. 3 shows an example of a gear ratio control device for a continuously variable transmission according to the present invention, to which the device is applied to control a clutch 7 and a switching gear disposed in a power transmission system from the engine 1 to the driving wheels 12. Gear train 8. 1 schematically shows the entire electronically controlled continuously variable transmission device including a continuously variable transmission 9 and an electronic control circuit section 22.

Here, various control signals 81 to S from the electronic control circuit section 22
6, the clutch connection control signal S1 is transmitted to the clutch control valve 29.
The clutch cutoff control signal S2 energizes the cutoff solenoid 31 of the clutch control valve 29 in order to energize it, and the shift up control signal S3 energizes the speed increase solenoid 33 of the speed change control valve 32. The shift down control signal S4 causes the deceleration solenoid 34 of the speed change control valve 32 to be energized with a predetermined duty, and the line pressure control signal S5 causes the line pressure control valve 37 to be energized with a predetermined duty, as will be described later. and a throttle control signal S6 is supplied to the throttle actuator 4 to operate it and adjust the opening degree of the throttle valve 3.

And Tarafuchi actuator 41. The continuously variable transmission 9 and the shift actuator 44 include - the above-mentioned clutch control valve 29. The oil pump is controlled by the shift control valve 32 and the shift control valve 43, which is controlled by switching the shift lever 27 to the reverse R, neutral N, drive D, and low gear positions by manual operation by the driver. 36, hydraulic oil sucked from the oil tank through the filter 35 and discharged is supplied through each oil passage.

The electronically controlled continuously variable transmission that is supplied with hydraulic oil and controlled in this manner is capable of transmitting the output of the engine I to the drive wheels I2 and controlling it as described below. It is configured as follows.

That is, the rotation of the output shaft 6 of the engine 1 begins with the rotation of the output shaft 6.
The signal is intermittently pressure-connected to a flywheel 38 provided at the end of the output shaft 6, and is transmitted to a clutch 7 that 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 pressing plate that presses the friction plate 39 is fixed, and the clutch connection control signal S1 is transmitted to the clutch control valve. When the oil is sent to the connection solenoid 30 of No. 29, the connection solenoid 30 is energized and turned on, and as a result, the hydraulic oil is supplied from the open port to the Thalassotia actuator 41, and the piston inside it is moved by the elasticity of the spring. The lever 42 is moved counterclockwise to rotate the lever 42 counterclockwise. As a result, the clutch spring 40 in the open state
is moved to the closed state, pressing the friction plate 39, and the clutch 7 is brought into the connected state. Thereby, the rotation of the output shaft 6 of the engine 1 is transmitted to the output side of the clutch 7.

Further, the clutch disconnection control signal S2 is transmitted to the clutch control valve 29.
When the oil is sent to the cut-off solenoid 31, the cut-off solenoid 31 is energized and turned on, and working pressure oil is discharged from the Thalassotia actuator 41, and the piston is returned by the elasticity of the spring inside the clutch spring. 40 is in an open state. As a result, the pressing state of the friction plate 39 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 not transmitted to the output side of the clutch 7.

Further, a clutch connection control signal S is sent to the connection solenoid 30 and cutoff solenoid 31 of the clutch control valve 29.
1 and clutch disconnection control signal S2 are not sent, the opening boat of the clutch control valve 29 is closed, and the piston in the Tarafuta actuator 41 is maintained in its immediately previous state, so that the flywheel 38 of the friction plate 39 The pressed state is maintained.

The output side of the clutch 7 that operates in this manner transmits the rotation of the output shaft 6 of the engine 1 to the input shaft 16 of the continuously variable transmission 9 in accordance with the above-mentioned respective shift positions of the shift lever 27. A switching gear train 8 is provided. This switching gear train 8 is configured such that when the shift lever 27 is placed in the drive D or low L position, the piston of the shift actuator unique 44 moves in the D direction in the figure, and the forward movement of the shift lever 27 fixed to the output shaft 14 of the clutch 7 moves. The input shaft 1 of the continuously variable transmission 9 is attached to the gear 45 for
The gear 46 provided at the clutch 7 is engaged 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, when the shift lever 27 is placed in the reverse R position, the piston of the shift 1 hair actuator 44 moves in the R direction in the figure, and the gear 47 provided on the input shaft 1G of the continuously variable transmission 9 changes the output of the clutch 7. Engages with an idle gear 49 that is engaged with a reverse gear 48 fixed to the shaft 14,
The input shaft 16 of the continuously variable transmission 9 is rotated in the opposite direction to that of the drive D described above, that is, in the same direction as the output shaft 14 of the clutch 7. Furthermore, when the shift lever 27 is placed in the neutral N position, the shift actuator 4
The piston 4 is held in the center of the cylinder so that the rotation of the output shaft 14 of the clutch 7 is not 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. The rotation of the pulley 50 and the drive pulley 50 is the V-belt 5.
1, and an output shaft 10 that rotates integrally with the driven pulley 52.

The drive pulley 50 includes a movable conical plate 50a and a fixed conical plate 50.
The movable conical plate 50a and the fixed conical plate 50b have their conical surfaces facing each other to form a V-shaped pulley groove.

The movable conical plate 50a is provided with a cylinder chamber 50C behind it, and can slide in the axial direction so as to approach or separate from the fixed conical plate 50b depending on the state of supply of hydraulic oil to the cylinder chamber 50C. , and a fixed conical plate 50
b is fixed to the input shaft 16. On the other hand, driven pulley 5
2 also has the same configuration as the above-mentioned driving pulley 50, and a movable conical plate 52a and a fixed conical plate 52b form a 7-shaped pulley groove, and a movable circular Sfe plate 5211 is provided behind it. Depending on the state of supply of operating pressure oil to the cylinder chamber 52c, it can slide in the axial direction so as to approach the fixed conical plate 52b, and the fixed conical plate 52b 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. When transmitting the rotation of the drive pulley 50 to the driven pulley 52, the rotation radius on the drive pulley 50 side of the V-belt 51 determined by the width of the pulley groove of the drive pulley 50 and the width of the pulley groove of the driven pulley 52 are used. Determined V bell) -5
By changing the radius of rotation on the driven pulley 52 side, the rotation ratio between the drive pulley 50 and the driven booby IJ52 can be changed.

The widths of the pulley grooves of the driving boo 1J50 and the driven pulley 52 are changed by sliding the respective movable conical plates 50a and 52a in the axial direction, and the sliding control of the movable conical plates 50a and 52a This is performed by the shift control valve 32 which receives the shift amplifier control signal S3 and the downshift control signal S4 from the electronic control circuit section 22 described above. That is, when the shift amplifier control signal S3 from the electronic control circuit section 22 is supplied to the speed increase solenoid 33 of the speed change control valve 32, the speed increase solenoid 33 is intermittently energized and turned on and off, and this According to the control duty of the shift amplifier control signal S3, the drive pulley 50
The operating pressure oil is supplied to the cylinder chamber 50c of the driven boob 1J52, and the operating pressure oil is removed from the cylinder chamber 52c of the driven boob 1J52.On the other hand, when the downshift control signal S4 is supplied to the deceleration solenoid 34, the deceleration solenoid 34 is intermittently activated. is excited and turned on and off, which causes
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. Furthermore, when both the speed increase solenoid 33 and the deceleration solenoid 34 are turned off, the respective cylinder chambers 5 of the drive boob IJ50 and the driven pulley 52
The supply and removal of hydraulic oil to 0c and 52C is stopped.

Therefore, the speed increasing solenoid 33 outputs the shift up control signal S.
3, when the on/off state is set, the movable circle ji
The r plate 50a is moved in a direction approaching the fixed conical plate 50b, and the width of the pulley groove formed by the movable conical plate 50a and the fixed conical plate 50b is reduced, and the drive pulley 50 side of the bell 1-51 is The radius of rotation at is expanded. Also,
At the same time, the movable conical plate 52a is moved in a direction away from the fixed conical plate 52b, and the movable conical plate 52a is moved away from the fixed conical plate 52b.
The width of the pulley groove formed by the fixed conical plate 52b is expanded, and the radius of rotation of the belt transmission force on the driven pulley 52 side 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 shift down control signal S4, the width of the pulley groove of the drive pulley 50 is expanded, contrary to the above case, and the drive pulley 50 of the belt 51 is The rotation radius on the side is reduced, and at the same time, the width of the pulley groove of the driven pulley 52 is reduced.
The radius of rotation on the 52 side is expanded. Therefore, in this case, the JIS speed change in the continuously variable transmission 9 is set to be large. Furthermore, the speed increase solenoid 33 and the speed reduction solenoid 3
4, when neither the shift amplifier control signal S3 nor the shift down control signal S4 is sent out and each solenoid is turned off, the width of the pulley groove of each of the drive boob IJ50 and the driven pulley 52 is maintained unchanged, and therefore, the drive pulley 50 of Bell I 51
The respective rotation radii on the side and the driven pulley 52 side are maintained, and the speed change in the continuously variable transmission 9 is maintained at the speed immediately before the speed increase solenoid 33 and the speed reduction solenoid 34 were turned off.

In this way, the continuously variable transmission is capable of continuously changing the gear ratio by changing the supply state of hydraulic oil to the cylinder chambers 50C and 52C of the driving pulley 50 and the driven boob IJ 52, respectively. 9, the greater the required running driving force, the greater the pressing force of the movable conical plates 50a and 52a against the belt 51;
(1) It is necessary to increase the belt transmission force (transmission 1-lux capacity of V-bell I/51) by belt 5 (5). 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
Line pressure control valve 3 receiving line pressure control signal S5 from
7. 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 higher the level of the line pressure control signal S5, the lower the amount of oil discharged and the higher the line pressure.

In an example of the gear ratio control device for a continuously variable transmission according to the present invention as shown in J-E above, when the vehicle is accelerating, the change in the accelerator opening degree α detected by the accelerator distance detection sensor 24 is used to detect the acceleration. It is detected that the accelerator pedal 23 has been depressed. Then, the electronic control circuit unit 22 sets the vehicle acceleration to be obtained at that time as the target vehicle acceleration G1 based on the change α° in the accelerator opening α. The engine speed Ne and throttle valve opening Th that can be obtained continuously during the period when the pedal is depressed for acceleration and with the minimum fuel consumption are maintained at the target engine speed TNe and the target throttle valve opening. They are respectively set as degrees TTh.

Then, the shift-up control signal S3 or the shift-down control signal S4 is supplied to the speed change control valve 32 so that the target engine speed TNe is obtained, and the continuously variable transmission 9
At the same time, the throttle control signal S6 is supplied to the throttle actuator 4 to control the throttle valve 3 so that the target throttle valve opening TTh can be obtained.

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 indicates the vehicle speed V.
In the running driving force characteristic shown by taking the running driving force FQ on the vertical axis, suppose that there is a transition from point d1 on curve F, l2 to point d2 on curve F2, then the relationship between this point d2 and point d1 is The acceleration corresponding to the difference in driving force between the two is set as the target vehicle acceleration G7. These points d and d2 are the output shaft rotation speed NO of the continuously variable transmission a9, which calculates the accelerator opening α, the change in the accelerator opening α when the accelerator pedal is depressed for acceleration α゛, and the vehicle speed ■. You can know from etc. In order to maintain this target vehicle acceleration G7 continuously until the acceleration state of the vehicle is released and the vehicle returns to point d4 on curve F2, the running driving force characteristic curve F2''2'' that moves from point d2 is necessary. It is necessary to move the point d3 to the point d3 corresponding to the point d4.

For this purpose, engine 1, carburetor F2, point d
It is required that the engine output is sequentially changed from ω to -+ω2-+ω3-ω4-ω5 according to the running drive characteristic curve W with the engine output crossing between points 2 and d3 as a parameter. In this example, the engine output ω1→ω2−(1) 3−ω4−ω
The engine speed Ne and the throttle valve opening Th are controlled so that a change of 5 is obtained with the minimum fuel consumption.

By the way, as shown in FIG. 5, there is an optimum fuel consumption zone Z in the power source characteristics of the engine 1, which is shown by taking the engine speed Ne on the horizontal axis and the engine torque T on the vertical axis. In controlling this zone Z, the engine output of the power source characteristic curve W' with the engine output as a parameter is set to ω7. ω2. ω3. ω4. The point where ω5 crosses "It e, 2-" 3+ e
4+ ” Engine speed N e 1. N
e2. N e3. N e4. Points eH, e2 . e3. es, Throttle valve opening degree of the thing passing through es T h l + T h 2. T
H.

Th4. Th5 is the target throttle valve opening TTh
It is said that Then, the shift amplifier control signal S3 and the shift down control signal S4 from the electronic control circuit section 22 are supplied to the speed increase solenoid 33 and the speed reduction solenoid 34 of the speed change control valve 32 in a predetermined manner, thereby controlling the target engine speed. The gear ratio control of the continuously variable transmission 9 is performed such that T N e is sequentially 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. The opening degree of the throttle valve 3 is controlled so that the target throttle valve opening degree TTh is successively achieved.

As a result, when the vehicle accelerates, the engine 1 is in the optimal fuel consumption state and its engine output is ω1-ω2-ω3-ω4-ω.
, and as a result, the set target vehicle acceleration GT is continuously obtained during the period when the accelerator pedal 23 is depressed for acceleration.

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 position of the shift lever 27 detected by the shift lever position detection sensor 28 is in the drive position. If it is in the range (D), the target vehicle accelerations c and r mentioned above are newly set to 0 in order to keep the vehicle speed at a constant speed that is continuously maintained at the time when the accelerator pedal 23 is released. be done so that it may be accomplished.

Therefore, when the accelerator pedal 23 is returned, the engine rotation speed Ne and throttle valve opening are set to achieve the target vehicle acceleration set to 0, that is, to set the actual vehicle acceleration G to O. Th is set as a target engine speed TNe and a target throttle valve opening TTh, respectively, and a shift up control signal S3 and a shift down control signal P4 are sent to the speed change control valve 32 so that the target engine speed TNe is obtained. is supplied to control the gear ratio of the continuously variable transmission a9, and a throttle control signal S6 is sent to the throttle actuator 4 so as to obtain the target throttle valve opening TTh.
is supplied to control the throttle valve opening Th.

In this case, the point d on the curve F2 in FIG.
When the vehicle speed corresponding to 3 is obtained, press the accelerator pedal 2.
3 is performed, point d3 on curve F2
It is necessary to move from the point to the point d4 on the curve F2. To this end, the engine 1 must sequentially change its output from ω to ω3 in accordance with the running drive characteristic curve W whose parameter is the engine output that crosses between points d3 and d4 on the curve F2. required.

In this example, the change in engine output is also
The engine speed Ne and the throttle valve opening Th are controlled so as to obtain the minimum fuel consumption. That is, in the above-mentioned FIG. 5, the engine rotational speed Ne5 and the throttle valve opening Th4 at a point e5 where the engine output is ω5 of the power source characteristic curve W'' with the engine output as a parameter crosses the zone Z. This is at the time when the return operation of the accelerator pedal 23 is started, and from this engine speed Nes and throttle valve opening Th5, the engine at the point e3 where the engine output ω3 of the power source characteristic curve W crosses, respectively. The target engine speed TNe and the target throttle valve opening TTh are set so that the rotational speeds Ne and l and the throttle opening Th are decreased as much as possible along the zone Z through the engine rotational speed Ne and the throttle opening Th4.
are sequentially set, and the gear ratio control of the continuously variable transmission 9 and the control of the target throttle valve opening Th are performed so that these target engine speed TNe and target throttle valve opening TTh are achieved.

This causes the shift lever 27 to shift to the drive range (D).
If the return operation of the accelerator pedal 23 is performed when the engine 1 is in the state of The vehicle is in a constant speed driving state where the vehicle speed is maintained.

The state of change from the constant acceleration variable speed running state to the constant vehicle speed running state as described above is shown in FIG. 6A as a graph in which the vertical axis represents the accelerator opening α and the horizontal axis represents time. FIG. 6B is a graph in which the vertical axis represents the vehicle speed V and the horizontal axis represents time. Here, a case where the amount of depression of the accelerator pedal 23, and hence 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 by a solid line in FIG. 6B. In addition, a case where the amount of depression of the accelerator pedal 23, and therefore the amount of change in the accelerator opening degree α, is small is shown by a chain line in the sixth country, and the corresponding change in the vehicle speed V is shown in the sixth country. It is shown in dashed lines in Figure B. As is clear from these graphs, assuming that the period (to to 1+) from the time point 1o when the accelerator pedal 23 starts to be depressed to the time t when the accelerator pedal enters the holding state after being depressed is the same, the amount of change in the accelerator pedal 23 is When is large, the target vehicle acceleration G is larger than when it is small, and therefore the vehicle speed
In either case, the time t when the accelerator pedal 23 starts to be depressed. from accelerator pedal 2
3 enters the hold state 1. through the accelerator pedal 23
The period (to to t
In case 2), a constant acceleration is continuously obtained and the vehicle speed ■ continues to increase. When the amount of change in the accelerator pedal 23 is large, the increase in vehicle speed at time t2 is larger than when it is small, and when the return operation of the accelerator pedal 23 is performed at time t2, from then on, , the vehicle speed at time t2 is maintained, and the vehicle is running at a constant speed.

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. Examples of programs executed by the CPU 20 are shown in FIGS. 7, 8, and 9. This will be explained with reference to the flowcharts in Figures A and B.

First, as shown in FIG. 7, after the start, process 6
In step 0, initial settings are made for each part, and then in process 61, data obtained based on the signals obtained from each sensor are inputted, and the process proceeds to process 62. In process 62, a program for clutch control is executed, Next, process 6
In step 3, a program for controlling the gear ratio and throttle valve opening is executed, and the process returns to process 61.

An example of a program for clutch control executed in the above-described process 62 is as shown in FIG. Here, after the start, decision 70
Now, the shift lever 27 is in the neutral range (N
If the shift I-lever 27 is in the neutral range position, the vehicle speed flag is reset in process 71. Then, in the subsequent process 72, a clutch disconnection control signal S2 is sent to the disconnection solenoid 31 of the clutch control valve 29, turning the disconnection solenoid 31 on and the connection solenoid 30 off. As a result, the clutch 7 is brought into the disconnected state.

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

In decision 75, it is determined whether the change Ne' in the engine speed Ne is positive or negative. If the change Ne' in the engine speed Ne is positive, in decision 76, the engine speed Ne is changed to the clutch output. It is determined whether the shaft rotation speed is greater than the shaft rotation speed Nc.

If it is determined that the engine rotation speed Ne is greater than the clutch output shaft rotation speed Nc, a clutch connection control signal S1 is sent to the connection solenoid 30 of the clutch control valve 29 in process 77, and the connection solenoid 30 is turned on. At the same time, the cutoff solenoid 31 is turned off. This causes the friction plate 39 of the clutch 7 to press the flywheel 38, and the transmission torque capacity of the clutch 7 gradually increases. Further, if it is determined in decision 76 that the engine rotation speed Ne is smaller than the clutch output shaft rotation speed Nc, the process advances to process 79;
At 9, neither the clutch connection control signal S1 nor the clutch disconnection control signal S2 is transmitted, and both the connection solenoid 30 and the disconnection solenoid 31 are turned off. As a result, the current state of the friction plate 39 of the clutch 7 pressing against the flywheel 38 is maintained, and therefore the transmission torque capacity of the clutch 7 is maintained as it is.

On the other hand, in decision 75, engine speed Ne
If it is determined that the change amount Ne' is negative, the process proceeds to decision 78, where it is determined whether the engine rotation speed Ne is smaller than the clutch output shaft rotation speed Nc,
If the engine rotation speed Ne is smaller than the clutch output shaft rotation speed Nc, the process proceeds to process 77. As a result, the transmission torque capacity of the clutch 7 gradually increases as described above.

If it is determined in decision 78 that the engine speed Ne is not smaller than the clutch output shaft speed Nc, the process proceeds to process 79, in which both the connection solenoid 30 and the cutoff solenoid 31 are turned off, as described above. Ru.

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

On the other hand, if it is determined in decision 80 that the accelerator pedal 23 is not in the on state, it is determined in decision 81 whether or not the vehicle speed flag is in the set state, and if the vehicle speed flag is in the set state, decision 82 , the brake pedal 25 is in the on state, that is, the brake pedal 25 is in the on state.
If it is determined that the brake pedal 25 is in the on state, the process advances to decision 83. If it is determined in 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 31 is turned off, as described above.

Then, in decision 83, the engine speed N
It is determined whether e is less than a predetermined value, for example 1500 rpm. Here, the engine rotation speed is 150 rpm
is the rotation speed that may cause the engine to stop when the brake pedal 25 is on. If the engine rotation speed Ne is not below 1500 rpm, the process advances to decision 75, and the flow as described above is followed. move on. If the engine speed Ne is 150 Orpm or less, the process proceeds to process 71, and the process proceeds as described above.

As a result of decision 82, the brake pedal 2
5 is not in the on state, the process proceeds to decision 84, where it is determined whether or not the engine rotational speed Ne is less than or equal to a predetermined value, for example 11000 rpm.

Here, the engine rotation speed 1100 Orp is the rotation speed that may cause the engine to stop when the brake pedal 25 is in the OFF state, and the engine rotation speed Ne is 1100 Orp.
If the rpm is not less than 1000 rp, the process proceeds to the digital controller 75, and the process proceeds as described above. On the other hand, if the engine speed Ne is 1100 Orp or less, the process proceeds to process 71, and the flow proceeds as described above.

Next, an example of a program for controlling the gear ratio and throttle valve opening degree executed in process 63 of the program shown in FIG. 7 is as shown in FIGS. 9A and 9B. Here, as shown in FIG. 9A, after the start, in decision 101, the state of change in the accelerator opening degree α is determined based on the accelerator opening degree signal P1, and it is determined that the accelerator opening degree α has increased. If so, 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, Decision 1 proceeds when it is determined that the accelerator opening degree α has not changed.
At step 03, it is determined whether the shift flag is in the cent state or not.
If it is determined that it is in the set state, the process 104
Proceed to.

In process 104, the variation α' is obtained from the accelerator opening α used in decision 101, and based on this variation α°, the variation α as shown in FIG.
The target vehicle acceleration GT is set from a map representing the correspondence between " and the target vehicle acceleration G7. Continued process 10
5, the actual vehicle speed at that time is V as the vehicle speed ■. In the following process 106, the actual vehicle speed read in process 105 is calculated based on the road surface slope obtained from the slope signal P9.
Based on o, the running resistance FL of the vehicle at that time is calculated. Note that this running resistance FL is calculated from the gradient resistance RK, rolling resistance Rr, and air resistance Ri.

Next, as shown in FIG. 9B, the process proceeds to process 107, where the target vehicle accelerations c and r set in process 104 are determined.
The traveling driving force Fe for achieving the above is calculated by adding the acceleration resistance Ra to the traveling resistance FL obtained in process 106. Then, in the subsequent process 108,
Engine output Pe required to achieve the running driving force Fe calculated in process 107 with minimum fuel consumption,
That is, the engine output ω as shown in FIG.
1. ω2. ω3. ω4. ω, and process 109
Proceed to. In the process 109, the point eI+ 82. as shown in FIG. ":l+"4-"The engine rotational speeds NeI, Nez, Ne3.N in the above-mentioned FIG.
e4. The target engine speed TNe as indicated by N e s and the throttle valve opening T h + also in FIG.

Thz, Th8. T, h4. A target throttle valve opening degree TTh as indicated by Ths 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 determination, if the actual engine speed Ne is higher than the target engine speed TNe, in process 111, the shift amplifier control signal S3 is transmitted to the speed increasing solenoid 3 of the speed change control valve 32.
3, the speed increasing solenoid 33 is turned on and off, and the deceleration solenoid 34 is turned off. With this,
The gear ratio in the continuously variable transmission 9 is made small, and as a result, the input shaft rotational speed Np of the continuously variable transmission 9 is reduced, and at this time, since the clutch 7 is in the connected state, the engine rotational speed Ne is also reduced. It will be done.

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, a shift down control signal S4 is sent to the deceleration solenoid 34 of the speed change control valve 32, and the deceleration solenoid is activated. 34 is turned on and off, and the speed increasing 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 Np of the continuously variable transmission 9 and, therefore, the engine rotation speed Ne are increased. In this way, the actual engine speed Ne is made to match the target engine speed TNe by the operation of 1. Process 111 or 112.

Next, the process proceeds to decision 113, where it is determined whether or not the actual throttle valve opening Th at that time is greater than the target throttle valve opening TTh calculated in process 109. If so, the process proceeds to step 114. In step 115, a throttle control signal S6 is sent to the throttle actuator 4 to reduce the throttle valve opening, thereby reducing the throttle valve opening Th. A throttle control signal S6 is sent to increase the throttle valve opening Th. 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, from decision 101 to process 115
In the flow leading to , the gear ratio n and the throttle valve opening Th are controlled to obtain a predetermined target vehicle acceleration G7 with the minimum fuel consumption while the accelerator is being depressed or during the subsequent depression holding period.

On the other hand, the aforementioned decision 101 shown in FIG. 9A
If it is determined that the accelerator opening degree α is decreasing, the process proceeds to process 116 to reset the gear shift flag, and then proceeds to process 117 to reset the vehicle speed flag indicating that constant speed driving is requested. Then, when it is determined that the shift flag is not in the cent state in decision 103 described above, decision 118 is executed.
Proceed to. In 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).
If it is determined that it is not in the drive range (L range), that is, if it is in the drive range (D range), the following decision 11
At step 9, it is determined whether 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 Vc at that time is read as the vehicle speed ■ in the same manner as process 105 described above, and in the subsequent process 121, the vehicle speed flag is set. Process 12
Proceed to step 2. On the other hand, if it is determined in decision 119 that the vehicle speed flag is in the Seso I state, the process directly proceeds to process 122 .

Then, in process 122, the target vehicle acceleration GT is set to 0, and the process proceeds to process 106, whereupon processes 106 to 115 are sequentially executed in the same manner as described above. In this case, the target vehicle acceleration GT is set to 0, so the acceleration resistance Ra is set to 0, and the running driving force Fe of the vehicle calculated in process 107 becomes equal to the running resistance FL, so that the vehicle runs at a constant speed, Furthermore, the optimal fuel consumption state is maintained even when the vehicle is running at a constant speed.

If it is determined that the low range L is selected in the above-described decision 119, the process proceeds to process 123, where a target gear ratio nT is set in accordance with the vehicle speed ■.

Next, in decision 124, it is determined whether or not the value is greater than n7, and if it is, the process proceeds to process 125, where a shift up control signal S3 is sent to the speed increasing solenoid 33 in order to reduce the gear ratio n. On the other hand, if it is small, the process proceeds to process 126, where a downshift control 4fl signal S4 is sent to the deceleration solenoid 34 to control the gear ratio in order to increase the gear ratio n.

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 reduce the throttle valve opening Th, and the throttle actuator 4 is operated in the closing direction.

In this way, in processes 123 to 127, the target gear ratio n is set according to the vehicle speed ■, and the gear ratio control U is performed to achieve this target gear ratio nT. Engine braking is applied to ensure smooth deceleration.

(Effects of the Invention) As is clear from the above description, according to the gear ratio control device for a continuously variable transmission according to the present invention, the output of the engine of the vehicle is transmitted to the vehicle, which is the driven part, via the continuously variable transmission mechanism. In addition, when an operation is performed that increases the amount of operation of the accelerator adjustment means, such as depressing the accelerator pedal, the vehicle speed is The driving force is increased as the running resistance increases due to the increase in the accelerator, and the vehicle assumes a constant acceleration running state in which a constant vehicle acceleration corresponding to the amount of operation of the accelerator adjustment means is continuously achieved. ,
On the other hand, when an operation is performed that reduces the amount of operation of the accelerator adjustment means, such as a return operation of the accelerator pedal, the vehicle does not operate the accelerator adjustment means in the operating state and the subsequent holding state. The vehicle speed is assumed to be the same as that at the time when the vehicle speed is started, or a constant vehicle speed running state that is continuously maintained. Therefore, the gear ratio control device for a continuously variable transmission according to the present invention can provide the driver of a vehicle equipped with the device with a sufficient sense of acceleration during acceleration.
Further, after acceleration, stable vehicle running at a constant speed can be performed.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of a gear ratio control device for a continuously variable transmission according to the present invention, and FIG. 2 is a drive control section of a vehicle to which an example of the gear ratio control device for a continuously variable transmission according to the present invention is applied. FIG. 3 is a schematic configuration diagram showing an example of the gear ratio control device for a continuously variable transmission according to the present invention together with an electronically controlled continuously variable transmission to which the same is applied; FIG. 4 , Figure 5,
6A and B and FIG. 10 are characteristic diagrams used to explain the operation of the example shown in FIG. 3, and FIGS. 7, 8, and 9
Figures A and B are flowchart 1 showing an example of an operation program in the electronic control circuit section used in the example shown in FIG. In the figure, 1 is an engine, 3 is a throttle valve, 7 is a 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 sensor, and 32 is a speed change control valve. Patent applicant Mazda Motor Corporation Figure 6

Claims (1)

[Claims] a gear ratio adjustment unit that changes the gear ratio of a continuously variable transmission mechanism provided in a power transmission path from the engine to the wheels of the vehicle;
A detection unit detects the operation state of the accelerator adjustment means for changing the load of the engine, and the operation of the accelerator adjustment means detected by the detection unit is made to increase the amount of operation of the accelerator adjustment means. when the operation of the accelerator adjusting means detected by the detecting section is to decrease the amount of operation of the accelerator adjusting means, a predetermined target means for setting a vehicle speed, and for causing the vehicle to selectively take a constant acceleration driving state in which the target vehicle acceleration is continuously achieved or a constant vehicle speed driving state in which the target vehicle speed is continuously achieved, A gear ratio control device for a continuously variable transmission, comprising: a control unit including means for sending a control signal to the gear ratio adjusting unit.