JPH052865B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses a continuously variable transmission mechanism that can continuously change the input/output torque ratio to transmit engine output to driven parts in an automobile. The present invention relates to an electronically controlled continuously variable transmission device in which the continuously variable transmission mechanism is controlled by electronic control means that generates a control signal based on a detection signal obtained by detecting an engine load state or the like.

(Prior art) In automobiles, 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. It is made to communicate,
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 automobiles is, for example, disclosed in Japanese Patent Application Laid-Open No.
As described in Publication No. 76709, the gear ratio is controlled based on the vehicle speed or engine speed and the throttle valve opening adjusted by operating an accelerator adjustment means such as an accelerator pedal. be done. 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. For example, control is performed such that the relationship between the throttle valve opening Th and the input shaft rotational speed Np of the continuously variable transmission mechanism follows the speed change characteristics as shown in FIG. In the shift characteristics shown in FIG. 1, the area labeled "down" is a downshift area, and the area labeled "up" is an upshift area. In this type of control, detection signals from the throttle valve opening detection means and the input rotation speed detection means of the continuously variable transmission mechanism are supplied to the electronic control means for the continuously variable transmission mechanism, and the electronic control means receives each detection signal. A corresponding control output is sent to the gear ratio adjustment section of the continuously variable transmission mechanism.

By the way, when speed ratio control is performed based on such speed change characteristics, a throttle signal system that detects the throttle valve opening and generates a detection output,
Alternatively, if an abnormality occurs in the input shaft rotational speed signal system that detects the input shaft rotational speed of the continuously variable transmission mechanism and generates a detection signal, a significant problem will occur in the operation of the continuously variable transmission mechanism. For example, if a wire breakage occurs in the throttle signal system and a detection signal cannot be obtained during normal driving of a car, the throttle valve opening degree is regarded as 0 in the electronic control means, and the continuously variable transmission mechanism According to the shift characteristics shown in the figure, control is performed to perform a sudden shift up, and this causes a phenomenon in which the automobile receives a significant shock. Further, if a disconnection occurs in the input shaft rotational speed detection system and a detection signal cannot be obtained, the electronic control means considers the input shaft rotational speed of the continuously variable transmission mechanism to be 0, and the continuously variable transmission mechanism According to the shift characteristics shown in the diagram, the vehicle will be controlled to perform a sudden downshift, and as a result, the vehicle will be in a state where strong engine braking is applied, which may cause the engine to overrun. There is.

Conventionally, countermeasures such as fixing the gear ratio of the continuously variable transmission mechanism to a constant value or shifting to the upshift side have been taken when an abnormality occurs in the detection system as described above, but the former method In this case, gear ratio control is not performed in response to changes in engine load, which causes problems such as strain on the engine and abnormally high engine noise.
The latter method is accompanied by problems such as a lack of driving force when restarting the vehicle or the possibility of clutch burnout.

In this way, if any abnormality occurs in the throttle signal system for detecting the throttle valve opening or the input shaft rotation speed signal system for detecting the input shaft rotation speed of the continuously variable transmission mechanism, the speed change will be interrupted. An abnormality occurs in the control signal sent from the electronic control means to the ratio adjustment means, and proper control of the continuously variable transmission mechanism cannot be expected.

(Object of the invention) The present invention has been made in view of the above points, and
In order to control the continuously variable transmission mechanism so as to follow predetermined speed change characteristics, necessary detection signals to be input to the electronic control means for supplying a control signal to the gear ratio adjustment means for controlling the gear ratio of the continuously variable transmission mechanism are provided. In the event that any abnormality occurs, the gear ratio control for the continuously variable transmission mechanism can be carried out regardless of the abnormality detection signal. It is an object of the present invention to provide an electronically controlled continuously variable transmission device that enables continuous driving.

(Structure of the Invention) An electronically controlled continuously variable transmission device according to the present invention includes a continuously variable transmission mechanism that is connected to an engine and can continuously change a gear ratio, and a continuously variable transmission mechanism that changes the gear ratio of the continuously variable transmission mechanism. a gear ratio adjusting means for detecting the engine load, a detecting means for detecting the engine load and generating a first detection signal, and a detecting means for detecting the engine rotation speed or a rotation speed related thereto and generating a second detection signal; and electronic control means for the gear ratio adjustment means, the electronic control means being
and the second detection signal is abnormal or not, and if both detection signals are not abnormal, a predetermined signal is determined depending on both the engine load and the engine rotation speed or the rotation speed related thereto. In accordance with the first shift control characteristic, and if either the first or second detection signal is abnormal,
In response to the first or second detection signal that is not abnormal among them, a predetermined second or third shift control characteristic that involves only the engine load, engine speed, or rotation speed related thereto is determined. Then, a control signal is sent to the gear ratio adjusting means to control the gear ratio of the continuously variable transmission mechanism.

(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 an automobile to which an example of an electronically controlled continuously variable transmission according to the present invention is applied. In the figure, reference numeral 1 denotes a reciprocating piston type engine, in which an intake passage 2 is provided with a throttle valve 3 that controls the supply of combustion material. It is driven to open and close, and its opening degree is detected by a throttle position sensor 5. Note that 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 pyrotechnic fuel injection valve is disposed at 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 a drive mechanism 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
A transmission input shaft rotation speed detection sensor 17 detects the rotation speed of the continuously variable transmission 9, and a transmission output shaft rotation speed detection sensor 18 detects the rotation speed of the output shaft 10 of the continuously variable transmission 9, and therefore the vehicle speed. Installed in place. Then, the throttle position signal P ₅ from the throttle position sensor 5 mentioned above, the engine output shaft rotation speed signal P ₂ from the engine rotation speed detection sensor 13 mentioned above, and the clutch output shaft rotation speed signal P 2 from the clutch output shaft rotation speed detection sensor 15 are sent. Output shaft rotation speed signal
P ₄ , transmission input shaft rotation speed signal from transmission input shaft rotation speed detection sensor 17 P ₆ , transmission output shaft rotation speed signal from transmission output shaft rotation speed detection sensor 18
Each of _P8 is the interface section 19 and CPU2.
0 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.
The shift position of the shift lever 27 is detected by the shift lever position detection sensor 2.
8, an accelerator opening signal P ₁ corresponding to the amount of depression of the accelerator pedal 23, a brake operation signal P ₃ obtained by depression of the brake pedal 25, and a signal corresponding to the position of the shift lever 27. Shift lever position signal _P7 is
Each is input to the electronic control circuit section 22.

Based on the signals P ₁ to P ₈ obtained and input from each sensor, the electronic control circuit section 22 outputs various control signals S ₁ , S ₂ , S ₃ , S ₄ , S ₅ , S ₆ is output.

FIG. 3 shows the above-mentioned clutch 7, switching gear train 8,
1 schematically shows an example of an electronically controlled continuously variable transmission according to the present invention that includes a continuously variable transmission 9 and an electronic control circuit section 22. FIG. Here, the electronic control circuit section 22
Among various control signals S ₁ to _{S 6} , the A solenoid 30 of the clutch control valve 29 receives the clutch control signal S ₁ , and the B solenoid 31 of the clutch control valve 29 receives the clutch control signal S ₂ . Each of them is excited, and the state of supply of hydraulic oil to the clutch 7 is controlled. Further, in response to the shift control signal S ₃ , the C solenoid 33 of the shift control valve 32 operates, and in response to the shift control signal S ₄ , the D solenoid 34 of the shift control valve 32 operates.
Each of them is excited, the state of supply of working pressure oil to the continuously variable transmission 9 is controlled, and its gear ratio is controlled.

Furthermore, the shift control valve 43 is controlled by switching the shift lever 27 to forward D, neutral N, and reverse R shift positions by manual operation by the driver, and the clutch control valve 29 described above.
and the speed change control valve 32 are supplied with operating pressure oil from an oil tank via a filter 35 and a hydraulic pump 36. The line pressure supplied from the hydraulic pump 36 is adjusted by a pressure reducing valve 37 that receives a line pressure control signal _S5 from the electronic control circuit section 22.

Furthermore, the throttle actuator 4 operates in response to the throttle control signal _S6 , thereby
The opening degree of the throttle valve 3 is adjusted.

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
The signal is transmitted to a clutch 7 which is intermittently pressure-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 pressing plate that presses the friction plate 39 is fixed, and the clutch control signal _S1 is transmitted to the clutch control valve. 29
When the oil is sent to the A solenoid 30, the A solenoid 30 is energized and turned on, and as a result, the hydraulic oil is supplied from the open port to the clutch actuator 41, and inside the clutch actuator 41, the piston is moved by the elasticity of the spring. Move against it and press lever 4.
Rotate 2 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.

Also, the clutch control signal _S2 is transmitted to the clutch control valve 2.
When sent to the B solenoid 31 of No. 9, B
The solenoid 31 is energized and turned ON, hydraulic oil is discharged from the clutch actuator 41, and the piston is returned by the elasticity of the spring inside the clutch actuator 41, so that the clutch spring 40 is opened. As a result, the pressing state of the friction plate 39 against the flywheel 38 is released, and
The clutch 7 is placed in a 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.

Furthermore, the A solenoid 3 of the clutch control valve 29
When neither the clutch control signals S ₁ nor S ₂ are sent to the 0 and B solenoids 31, the open port of the clutch control valve 29 is closed, and the piston in the clutch actuator 41 is returned to its previous state. Therefore, the pressing state of the friction plate 39 against the flywheel 38 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 in accordance with the forward D, neutral N, and reverse R shift positions of the engine. In this switching gear train 8, when the shift lever 27 is placed in the forward position D, the piston of the shift actuator 44 moves in the direction D in the figure, and the forward gear fixed to the output shaft 14 of the clutch 7 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, when the shift lever 27 is moved to the reverse position R, 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 moves towards the clutch 7. The input shaft 16 of the continuously variable transmission 9 engages with the idle gear 49 that is engaged with the reverse gear 48 fixed to the output shaft 14, and the above-mentioned forward drive D
In this case, the clutch 7 is rotated in the opposite direction, that is, in the same direction as the output shaft 14 of the clutch 7. 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 a V-shaped pulley groove is formed by a movable conical plate 52a and a fixed conical plate 52b, and the movable conical plate 52a is located behind the movable conical plate 52a. Depending on the state of supply of working pressure oil to the provided cylinder chamber 52c, it can be slid 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. And drive pulley 5
When transmitting zero rotation to the driven pulley 52, the rotation radius of the V-belt on the drive pulley 50 side is determined by the width of the pulley groove of the drive pulley 50, and the driven drive of the V-belt is determined by the width of the pulley groove of the driven pulley 52. By changing the rotation radius on the 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 52a in the axial direction. A speed change control valve 32 is provided for this purpose. This speed change control valve 32 is connected to the electronic control circuit section 22.
C is turned on and off by the shift control signal _S3 from
A solenoid 33 and a D solenoid 34 which is turned on and off by the speed change control signal _S4 are provided.
When the C solenoid 33 is turned on,
While supplying working pressure oil to the cylinder chamber 50c of the driving pulley 50, the cylinder chamber 5 of the driven pulley 52
When the D solenoid 34 is turned on, the hydraulic oil is supplied to the cylinder chamber 52c of the driven pulley 52 and the hydraulic oil is removed from the cylinder chamber 50c of the driving pulley 50. do. Further, when both the C solenoid 33 and the D solenoid 34 are turned off, the supply and removal of hydraulic oil to the cylinder chambers 50c and 52c of the driving pulley 50 and the driven pulley 52, respectively, is stopped.

In the shift control valve 32 having the above-mentioned role, when the C solenoid 33 is turned on by the shift control signal _S3 , the hydraulic oil from the hydraulic pump 36 is supplied from the supply port to the cylinder chamber of the drive pulley 50. As a result, the movable conical plate 50a is moved in a direction approaching the fixed conical plate 50b, and the width of the pulley groove formed with the fixed conical plate 50b is reduced, and the drive pulley 50 of the V-belt 51 is The turning radius on the side increases. Also,
At the same time, the cylinder chamber 52 of the driven pulley 52
The working pressure oil filled in c is removed from the discharge port, thereby moving the movable conical plate 52a in a direction 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 V-belt 51 on the driven pulley 52 side is reduced. Therefore, the continuously variable transmission 9
The gear ratio becomes small. On the other hand, when the D solenoid 34 is turned on by the speed change control signal _S4 , the working pressure oil from the hydraulic pump 36 is supplied from the supply port to the cylinder chamber 52c of the driven pulley 52, contrary to the above case. At the same time, the working pressure oil is removed from the cylinder chamber 50c of the drive pulley 50, the width of the pulley groove of the drive pulley 50 is expanded, and the rotation radius of the V-belt 51 on the drive pulley 50 side is reduced. 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 in the continuously variable transmission 9 is made large. Furthermore, C solenoid 3
3 and D solenoid 34, a shift control signal
When neither S ₃ nor S ₄ is sent out 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 at the width immediately before it. , the drive pulley 50 side of the drive pulley 50 of the V-belt 51 and the driven pulley 5
The respective rotation radii on the second side are maintained, and the gear ratio in the continuously variable transmission 9 is kept at the one immediately before the C solenoid 33 and the D solenoid 34 were turned off.

In an example of the electronically controlled continuously variable transmission according to the present invention having the above-described configuration, in the electronic control circuit section 22, the accelerator opening degree α, which represents the load condition of the engine, is detected by the accelerator opening detection sensor 2.
4, and the input shaft rotation speed Np of the continuously variable transmission 9, which represents the rotation speed of the engine ₁ , is obtained by the transmission input shaft rotation speed detection sensor 17. It is detected from the input shaft rotation speed signal P ₆ , and if the accelerator opening signal P ₁ and the transmission input shaft rotation speed signal P ₆ are normal, then depending on the accelerator opening α and the input shaft rotation speed Np, As shown in Fig. 4, the graph is based on a predetermined shift characteristic diagram (hereinafter referred to as "X map"), which is expressed by plotting the input shaft rotational speed Np on the vertical axis and the accelerator opening α on the horizontal axis. In order to control the gear ratio of the continuously variable transmission 9, the gear change control signals _S3 and _S4 are sent to the gear change control valve 32, which is a gear change adjusting means.
The signal is sent to the C solenoid (C SOL) 33 and the D solenoid (D SOL) 34. The gear ratio control at this time is performed at a normal gear ratio change speed h'. With this gear ratio control, each accelerator opening α
For the value of , the input shaft rotation speed Np of the continuously variable transmission 9,
Therefore, the rotational speed of the engine 1 is made to take a constant value.

On the other hand, if the accelerator opening signal P ₁ obtained by the accelerator opening detection sensor 24 becomes abnormal due to, for example, a disconnection in the accelerator opening detection sensor 24, this is detected by the electronic control circuit section 22. , irrespective of the accelerator opening degree α at that time, depending only on the input shaft rotation speed Np detected from the transmission input shaft rotation speed signal _P6 , as shown in FIG. Continuously variable transmission 9 based on a transmission characteristic diagram (hereinafter referred to as Y map) in which only a predetermined input shaft rotation speed Np is involved.
In order to perform the gear ratio control, the gear change control signals S ₃ and S ₄ are sent to the C solenoid (C
SOL) 33 and D solenoid (D SOL) 34
will be sent to. The gear ratio control at this time is performed at a gear ratio changing speed h' that is smaller than usual. In gear ratio control, the input shaft rotation speed
Downshift control is performed until Np reaches a predetermined value, and after reaching the predetermined value, upshift control is performed.

Furthermore, if the transmission input shaft rotation speed signal P ₆ obtained by the transmission input shaft rotation speed detection sensor 17 becomes abnormal due to, for example, a disconnection in the transmission input shaft rotation speed detection sensor 18, This is detected by the electronic control circuit section 22, and regardless of the input shaft rotation speed Np at that time, the accelerator opening signal is
Depending only on the accelerator opening α detected from P ₁ ,
As shown in FIG. 6 in the same manner as FIG. In order to perform the control, the speed change control signal
S ₃ and S ₄ are the C solenoid (C
SCL) 33 and D solenoid (D SOL) 34
sent to. The gear ratio control at this time is also performed at a gear ratio changing speed h' that is smaller than usual. In this gear ratio control, downshift control is performed until the accelerator opening degree α reaches a predetermined value, and after reaching the predetermined value, shift up control is performed.

The predetermined value of the input shaft rotation speed Np in the Y map shown in FIG. 5 and the predetermined value of the accelerator opening degree α in the Z map shown in FIG. 6 are, for example, as shown in FIG. 4. From the input shaft rotation speed Np in the part shown by a to the input shaft rotation speed in the part shown by b on the characteristic curve in the X map
The input shaft rotation speed Np and the accelerator opening α at a point C, which is approximately halfway up until reaching the value of Np, are:
You can choose each.

A series of controls on the gear ratio of the continuously variable transmission 9 as described above are performed based on the operation of the CPU 20 of the electronic control circuit section 22, and an example of a program executed by the CPU 20 is shown in FIG. Figures 8 and 9
This will be explained with reference to the flowchart shown in the figure.

First, as shown in FIG. 7, after starting, initial settings are made for each part in process 60, then a program for clutch control is executed in process 61, and then a gear ratio and throttle control is executed in process 62. The program for controlling the opening degree of the tutle valve is executed and the process returns to process 61.

An example of a program for clutch control executed in the above-mentioned process 61 is as shown in FIG. Here, after the start, the shift lever is currently 27 at day 70.
It is determined whether the shift lever 27 is in the neutral range (N range) position, and if the shift lever 27 is in the neutral range position, the vehicle speed is adjusted in process 71. Set flag FV to reset state and continue process 7
2, a clutch control signal _S2 is sent to the B solenoid 31 of the clutch control valve 29, turning the B solenoid 31 on and the A solenoid 30 off. As a result, the clutch 7 is placed in the disconnected 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 FV with
Proceed to step 5.

Decision 75 determines whether the change Ne' in the engine output shaft rotation speed Ne is positive or negative. If the change Ne' in the engine output shaft rotation speed Ne is positive, decision 76 determines whether the engine output shaft rotation speed Ne is positive or negative. It is determined whether the rotational speed Ne is greater than the clutch output shaft rotational speed Nc. If it is determined that the engine output shaft rotation speed Ne is greater than the clutch output shaft rotation speed Nc, in process 77 the clutch control valve 2
A clutch control signal _S1 is sent to the A solenoid 30 of No. 9 to turn the A solenoid 30 on and the B solenoid 31 off. As a result, the friction plate 39 of the clutch 7 is connected to the flywheel 3.
8 is pressed, and the transmission torque capacity of the clutch 7 gradually increases.

On the other hand, if it is determined at decision 75 that the change Ne' in the engine output shaft rotation speed Ne is negative, the process proceeds to decision 78, where the engine output shaft rotation speed Ne is lower than the clutch output shaft rotation speed Nc. If the engine output shaft 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. At decision 78, the engine output shaft rotation speed Ne is the clutch output shaft rotation speed.
If it is determined that it is not smaller than Nc, the process proceeds to process 79, where the clutch control signal is
Both S ₁ and S ₂ are prevented from being delivered, thereby maintaining the current state of pressing the friction plate 39 of the clutch 7 against the flywheel 38, and therefore maintaining the current transmission torque capacity of the clutch 7.

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

On the other hand, the accelerator pedal is 23 at decision 80.
If it is determined that the vehicle speed flag FV is not on, decision 81 determines whether the vehicle speed flag FV is set. If the vehicle speed flag FV is set, decision 82 determines whether the brake pedal 25 is turned on. status, i.e. brake pedal 2
5 is depressed, and if it is determined that the brake pedal 25 is in the on state, the process advances to decision 83.

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

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

Next, an example of a program for speed ratio control executed in process 62 of the program shown in FIG. 7 is as shown in FIG. Here, after starting, process 101
Based on the accelerator opening signal _P1 obtained from the accelerator opening detection sensor 24, the accelerator opening α is read, and in the next decision 102, it is determined whether the accelerator opening detection sensor 24 is malfunctioning. If the decision 102 determines that the accelerator opening detection sensor 24 is not malfunctioning, the process 103
In step 103, the input shaft rotation speed of the continuously variable transmission 9 is determined based on the transmission input shaft rotation speed signal _P6 obtained from the transmission input shaft rotation speed detection sensor 17.
Np is read, and in the next decision 104 it is determined whether the transmission input shaft rotation speed detection sensor 17 is out of order. If it is determined in the decision 104 that the transmission input shaft rotation speed detection sensor 17 is not malfunctioning, that is, if both the accelerator opening detection sensor 24 and the transmission input shaft rotation speed detection sensor 17 are not malfunctioning, Proceeding to process 105, settings are made to perform normal gear ratio control in accordance with the When ratio control is performed, settings are made so that the gear ratio change speed h' becomes normal. Then, in process 107, shift control signals S ₃ and S ₄ are provided to the shift control valve 32 in order to perform gear ratio control based on the It is also sent to a C solenoid (C SOL) 33 and a D solenoid (D SOL) 34 for shift up control and shift down control.

If the decision 102 determines that the accelerator opening detection sensor 24 is out of order, the decision 102 proceeds to process 108, and in process 108 the accelerator opening detection sensor 24 is determined to be malfunctioning.
Without using the accelerator opening degree α obtained based on P ₁ , according to the input shaft rotation speed Np of the continuously variable transmission 9,
In anticipation of a failure of the accelerator opening detection sensor 24, settings are made to perform gear ratio control based on a predetermined Y map, and the next process 10 is performed.
At step 9, settings are made so that when gear ratio control based on the Y map is performed, the gear ratio changing speed h' is smaller than normal. And process 107
In order to perform the gear ratio control based on the Y map at the gear ratio change speed h' set in the previous process 109, the gear change control signals S ₃ and S ₄ are used to control the shift up and down of the gear change control valve 32. It is sent to the C solenoid (C SOL) 33 and D solenoid (D SOL) 34 for control.

Further, if the accelerator opening detection sensor 24 is operating normally, but the transmission input shaft rotation speed detection sensor 17 is determined to be malfunctioning at the decision 104, the process proceeds from the decision 104 to a process 110. In process 110, without using the input shaft rotation speed Np obtained based on the transmission input shaft rotation speed signal _P6 , according to the accelerator opening degree α,
In anticipation of a failure of the transmission input shaft rotation speed detection sensor 17, settings are made to perform gear ratio control based on a predetermined Z map, and in the next process 111, the settings are made to perform gear ratio control based on a predetermined Z map. When gear ratio control based on the Z map is performed, settings are made so that the gear ratio changing speed h' is smaller than normal. Then, in process 107, the shift control signals _S3 and _S4 are applied to the shift up of the shift control valve 32 in order to perform the gear ratio control based on the Z map at the gear ratio change speed h' set in the previous process 111. C for control and downshift control
It is sent to the solenoid (C SOL) 33 and the D solenoid (D SOL) 34.

As described above, in the process 107, the shift control signals S ₃ and S ₄ are sent to the C solenoid (C SOL) 33 and the D solenoid (D SOL) 34 provided in the shift control valve 32, respectively. The gear ratio control of the transmission 9 is performed, the program for the gear ratio control is ended, and the process returns to process 61 for performing clutch control.

(Effects of the Invention) As is clear from the above explanation, according to the electronically controlled continuously variable transmission according to the present invention, the gear ratio of the continuously variable transmission mechanism that transmits the output of the engine to the wheel where the driven part is By means of control means, normally
It is controlled appropriately based on both a signal according to the engine load and a signal according to the engine speed, and if for some reason the correct signal according to the engine load or engine speed cannot be obtained. When an abnormality occurs, the engine is controlled in a predetermined manner based on the other signal that is not abnormal, regardless of the signal that caused the abnormality. This results in a transmission ratio control state that can withstand practical use. Therefore, even if an automobile equipped with the electronically controlled continuously variable transmission according to the present invention is in an abnormal state as described above, it will not be subject to significant inconveniences such as sudden engine braking or engine overrun. You can perform basic driving without any problems.

[Brief explanation of drawings]

Fig. 1 is a speed change characteristic diagram for explaining general gear ratio control of a continuously variable transmission mechanism, and Fig. 2 is a drive control of an automobile to which an example of an electronically controlled continuously variable transmission according to the present invention is applied. FIG. 3 is a schematic configuration diagram showing an example of an electronically controlled continuously variable transmission according to the present invention, and FIGS. 4, 5, and 6 are schematic diagrams of the example shown in FIG. Characteristic diagram provided for explanation of operation, No. 7
8 and 9 are flowcharts 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, 7 is a clutch, 9 is a continuously variable transmission, 17 is a transmission input shaft rotation speed detection sensor,
22 is an electronic control circuit section, 23 is an accelerator pedal,
24 is an accelerator opening detection sensor, and 32 is a speed change control valve.

Claims (1)

[Claims] 1: a continuously variable transmission mechanism connected to an engine; a gear ratio adjustment means for controlling a gear ratio of the continuously variable transmission mechanism; a detection means for detecting a load condition of the engine and generating a first detection signal; a detection means for detecting the rotation speed of the engine or a rotation speed related thereto and generating a second detection signal; and a detection means for receiving the first and second detection signals and determining whether or not they are abnormal; If the first and second detection signals are not abnormal, the control is performed in accordance with a predetermined first shift control characteristic that involves both the engine load and the engine rotation speed or the rotation speed related thereto. In addition, when either of the first and second detection signals is abnormal, the engine load or engine rotation speed or related thereto is determined according to the first or second detection signal that is not abnormal. electronic control means for sending a control signal to the speed ratio adjusting means to control the speed ratio of the continuously variable transmission mechanism in accordance with a predetermined second or third speed change control characteristic that involves only the rotational speed; Electronically controlled continuously variable transmission.