JP2000035116A - Torque transmitting force control device for infinit transmission gear ratio continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly switch a power circulation mode from a direct-coupled mode or vice versa. SOLUTION: In an infinit transmission gear ratio continuously variable transmission provided with a variable speed control means for performing switching between a power circulation mode which controls tilt-rolling angle of power rollers 20 of a continuously variable transmission 2 and which drives a unit output shaft 6 at a unit transmission gear ratio corresponding to the continuously variable transmission 2, a constantly variable transmission 3, and a planetary gear mechanism 5 by engagement of a power circulation mode clutch 9, and a direct-coupled mode which drives the unit output shaft 6 at a transmission gear ratio of the continuously variable transmission 2 by engagement of a direct-coupled mode clutch 10, a means for detecting the tilt-rolling angle of the power rollers 20 of the continuously variable transmission 2, and a control means for controlling the engaging force of the power circulation mode clutch 9 and the direct-coupled mode clutch 10 in response to the tilt-rolling angle of the power rollers 20 when switching is performed between the power circulation mode and the direct-coupled mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission used for a vehicle or the like, and more particularly to a torque transmission force control device for an infinitely variable transmission.

[0002]

2. Description of the Related Art A belt-type or toroidal-type continuously variable transmission is conventionally known as a vehicle transmission. In order to further expand the shift range of such a continuously variable transmission, a continuously variable transmission is known. An infinitely variable speed ratio transmission in which the speed ratio can be controlled to infinity by combining a planetary gear mechanism with a gearbox is proposed in, for example, Japanese Patent Application No. 9-42428.

[0003] This is composed of a toroidal type continuously variable transmission in which the gear ratio can be continuously changed by tilting of a power roller held between an input / output disk, a constant transmission, and a planetary gear mechanism. A constant transmission is connected in parallel to a unit input shaft of a continuously variable transmission with an infinite transmission ratio connected to the engine.

The output shaft of the continuously variable transmission is connected to the sun gear of the planetary gear mechanism, and the output shaft of the constant transmission is connected to the carrier of the planetary gear mechanism via a low resume clutch (hereinafter referred to as a power circulation mode clutch). The ring gear of the planetary gear mechanism is connected to the unit output shaft, which is the output shaft of the infinitely variable transmission, and the output shaft of the continuously variable transmission connected to the sun gear has a direct clutch (hereinafter referred to as a direct-coupled mode clutch). To the output shaft of the unit.

In such a continuously variable transmission with an infinite transmission ratio,
By connecting the power circulation mode clutch and releasing the direct connection mode clutch as shown in FIG. 12, the unit speed ratio (IVT ratio) is reduced according to the speed ratio difference between the continuously variable transmission and the fixed transmission. Value (reverse) to positive value (forward)
Up to infinity (geared neutral in which the unit output shaft is stationary) to control the gearshift almost continuously, including a low-resume state (hereinafter referred to as the power circulation mode). The direct connection state (hereinafter, referred to as a direct connection mode) in which the transmission is controlled in accordance with the speed ratio (CVT ratio) of the continuously variable transmission can be selectively used.

[0006]

However, in such a conventional infinitely variable speed ratio continuously variable transmission, when the power roller of the continuously variable transmission reaches a predetermined tilt angle, the tilt angle is changed. Is switched between the power circulation mode and the direct connection mode while maintaining the power transmission constant.In this case, the torque transmission direction changes, that is, the force applied to the power roller is reversed. As a result, the power roller may tilt and deviate from the switching point.

For example, when switching from the power circulation mode to the direct connection mode, the engagement force of the direct connection mode clutch is
When the differential pressure for controlling the holding force of the power roller is not properly given, the power roller is vertically displaced, and the tilt angle changes. When this fastening force is greater than the differential pressure, the power roller tilts toward the Lo side (outer peripheral side of the output disk) with the CVT ratio. Conversely, when this fastening force is smaller than the differential pressure, the power roller tilts toward the Hi side (the inner peripheral side of the output disk) with the CVT ratio. Further, when switching from the direct connection mode to the power circulation mode, when the engaging force of the power circulation mode clutch is larger than the differential pressure, the power roller tilts toward the Hi side (the inner peripheral side of the output disk). In the opposite case, the CVT ratio tilts to the Lo side (the outer peripheral side of the output disk).

[0008] Therefore, the mode switching cannot be performed smoothly, and a shock may be caused to give an uncomfortable feeling to the occupant.

The present invention provides such a power circulation mode,
An object of the present invention is to solve a problem at the time of switching the direct connection mode.

[0010]

A first aspect of the present invention is to provide a continuously variable transmission and a constant transmission that continuously change the gear ratio by tilting a power roller held between input and output disks. And an infinitely variable speed ratio transmission in which the output shafts of the continuously variable transmission and the fixed transmission are connected to the unit output shaft via a planetary gear mechanism, a power circulation mode clutch and a direct coupling mode clutch. Controls the tilt angle of the power roller of the continuously variable transmission in accordance with the operating state, and engages the power circulation mode clutch to output the unit at a unit speed ratio corresponding to the continuously variable transmission, the constant transmission, and the planetary gear mechanism. A gear ratio control unit that switches between a power circulation mode for driving the shaft and a direct connection mode for driving the unit output shaft at a gear ratio of the continuously variable transmission by engaging a direct coupling mode clutch. In the torque transmission force control device for a continuously variable transmission, a means for detecting a tilt angle of a power roller of the continuously variable transmission, and a device for detecting a tilt angle of the power roller when switching between the power circulation mode and the direct connection mode. And a clutch force control means for controlling the engaging force of the power circulation mode clutch and the direct connection mode clutch.

According to a second aspect of the present invention, in the first aspect, the clutch force control means changes the tilt angle of the power roller when switching from the power circulation mode in the engaged state of the power circulation mode clutch to the direct connection mode. When the rate is smaller than a predetermined value, the engagement force of the direct connection mode clutch is reduced, and when the rate of change of the tilt angle is larger than the predetermined value, the engagement force of the direct connection mode clutch is increased.

[0013] In a third aspect based on the first aspect, the clutch force control means is configured to switch from the direct connection mode in which the direct connection mode clutch is engaged to the power circulation mode.
When the rate of change of the tilt angle of the power roller is larger than a predetermined value, the engaging force of the power circulation mode clutch is decreased, and when the rate of change of the tilt angle is smaller than the predetermined value, the engaging force of the power circulation mode clutch is increased. Control.

In a fourth aspect based on the first aspect, an input torque control means is provided for controlling the input torque to be constant when the engagement control of the power circulation mode clutch or the direct connection mode clutch is being performed.

[0014]

According to the first to third aspects of the present invention, the force applied to the power roller at the time of switching from the power circulation mode to the direct connection mode and at the time of switching from the direct connection mode to the power circulation mode is reduced. Even if the tilt angle changes, the change can be suppressed by increasing / decreasing control of the engaging force of the direct-coupled mode clutch and increasing / decreasing control of the engaging force of the power circulation mode clutch. Therefore, the tilt angle at the mode switching point is maintained. However, switching from the power circulation mode to the direct connection mode and switching from the direct connection mode to the power circulation mode can be smoothly performed, and the shock at the time of mode switching can be sufficiently reduced.

According to the fourth aspect, the fluctuation of the tilt angle of the power roller at the time of mode switching is reduced, and the shock at the time of mode switching can be further reduced.

[0016]

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

FIGS. 1 to 4 show a toroidal type continuously variable transmission (C).
1 shows an example in which a continuously variable transmission (IVT) with an infinite speed ratio is constructed using VT) 2.

As shown in FIG. 1, a toroidal type continuously variable transmission 2 capable of continuously changing the speed ratio is provided on a unit input shaft 1 of an infinitely variable speed ratio continuously variable transmission connected to an engine.
And a constant transmission 3 (reduction gear) composed of gears 3a and 3b, and these output shafts 4, 3
The output shaft 4 of the continuously variable transmission 2 is connected to the sun gear 5a of the planetary gear mechanism 5, and the output shaft 3c of the constant transmission 3 is connected to the planetary gear It is connected to the carrier 5b of the mechanism 5.

The output shaft 4 of the continuously variable transmission 2 connected to the sun gear 5a of the planetary gear mechanism 5
, The ring gear 5 c of the planetary gear mechanism 5 is connected to the unit output shaft 6.

The unit output shaft 6 is provided with a transmission output gear 7 which meshes with the final gear 12 of the differential gear 8 and is coupled to the differential gear 8 at a predetermined total reduction ratio. The driving force is transmitted to the driven shafts 11a and 11b.

The continuously variable transmission 2 has two sets of input disks 21.
The output roller 22 is a double-cavity toroidal type that sandwiches and presses the power roller 20, respectively. The lower end of the power roller 20 is supported by a hydraulic cylinder 30 and rotated around an axis as shown in FIG. It is supported by a movable trunnion shaft 23.

The hydraulic cylinder 30 is defined by a piston 31 into upper and lower oil chambers 30A and 30B, and a hydraulic pressure to the oil chamber 30A as a first oil chamber and an oil chamber 3 as a second oil chamber.
The oil pressure to 0B is controlled by the CVT control valve 40.

Here, in the power circulation mode in which the power circulation mode clutch 9 is engaged (during forward movement), the unit output shaft 6 has a speed ratio corresponding to the continuously variable transmission 2, the constant transmission 3, and the planetary gear mechanism 5. Is driven, and torque is transmitted from the output disk 22 to the power roller 20 and the input disk 21 in the continuously variable transmission 2.

In this case, as shown in FIG. 5, the hydraulic cylinder 30 sets the oil pressure of the oil chamber 30A to P _DEC and the oil pressure of the oil chamber 30B to P _DEC .
_{If INC} is set, the differential pressure ΔP = P _INC −P _DEC receives a torque transmitting force acting on the power roller 20 in a negative range (however, the drive state). On the other hand, the differential pressure Δ
When the pressure difference ΔP is changed from the state where P and the torque transmitting force of the power roller 20 are balanced, the piston 31
When the trunnion shaft 23 is displaced in the axial direction and the power roller 20 is displaced from the equilibrium position and the differential pressure ΔP is increased, the power roller 20 moves to the Lo side of the speed ratio (the inner peripheral side of the output disk 22). When the differential pressure ΔP is reduced, the power roller 20 is tilted to the Hi side of the gear ratio (the outer peripheral side of the output disk 22).

In the direct connection mode in which the direct connection mode clutch 10 is engaged, the unit output shaft 6 is driven at the speed ratio of the continuously variable transmission 2 (including the output gear trains 4a, 4b, 4c), and the continuously variable transmission is performed. In the machine 2, torque is transmitted from the input disk 21 to the power roller 20 and the output disk 22.

In this case, as shown in FIG. 5, the hydraulic cylinder 30 has a positive pressure difference ΔP = P _INC −P _DEC between the oil pressure P _DEC of the oil chamber 30A and the oil pressure P _INC of the oil chamber 30B.
Will receive the torque transmission force acting on the
Drive state). On the other hand, the differential pressure ΔP and the power roller 2
When the differential pressure ΔP is changed from a state where the torque transmission force of 0 is balanced, the trunnion shaft 23 is displaced in the axial direction together with the piston 31, the power roller 20 is displaced from the balanced position, and the differential pressure ΔP is increased. In this case, the power roller 20 is shifted to the Lo side of the gear ratio (the inner circumference of the input disk 21).
Meanwhile, when the differential pressure ΔP is reduced, the power roller 20 is tilted to the Hi side of the gear ratio (the outer peripheral side of the input disk 21).

The CVT control valve 40 has three lands 42b, 4 between both ends 42a, 42e of the spool 41.
2c and 42d are formed at a predetermined interval, and the spool 41 is directed to the left side in the figure between the right end 42e in the figure and the inner periphery of the CVT control valve 40 (hereinafter simply referred to as the inner periphery). A biasing spring 44 is interposed, and a solenoid valve 5 is provided on the inner circumference toward the end surface of the left end 42a in the figure.
The signal pressure port 43A for supplying the signal pressure P _SOL from the third port 3 is opened, and the spool 41 is urged to the right side in the figure facing the spring 44 according to the signal pressure P _SOL .

A port 4 communicating with the oil chamber 30A below the hydraulic cylinder 30 is provided on the inner periphery facing the left end 42a and the land 42b and between the land 42c and the land 42d.
3B and 43G are formed, and the right end 42e and the land 4 are formed.
Ports 43D and 43I communicating with the oil chamber 30B above the hydraulic cylinder 30 are formed on the inner circumference facing between the land 2d and the land 42b and the land 42c, respectively. Line pressure ports 43E and 43F communicating with a source pressure oil passage from a hydraulic supply source (not shown) are provided on an inner periphery facing the land 42c.
Is opened, and supplies the line pressure PL to one of the ports 43D or 43G according to the displacement of the land 42c. Drain ports 43C and 43H communicating with a drain tank (not shown) are opened on the inner periphery facing the lands 42b and 42d, and the ports 43 are provided according to the displacement of the lands 42b and 42d.
One of D or 43G is connected to the drain tank.

A drain port 43J is opened on the inner periphery facing the end 42e, and the hydraulic oil is discharged. Further, the outer diameters of the ends 42a, 42e of the spool 41 are set equal, the outer diameters of the lands 42b, 42c, 42d are also set equal, and the outer diameter of the lands is set larger than the outer diameter of the ends. .

Here, when the signal pressure P _SOL is increased, the spool 41 is displaced to the right in the drawing, so that the ports 43E and 43D communicate with each other and the line pressure PL is supplied to the oil chamber 30B of the hydraulic cylinder 30, and the oil pressure is increased. While the hydraulic pressure P _INC applied to the chamber 30B increases, the drain port 43H and the port 43G communicate with each other in accordance with the displacement of the land 42d. Therefore, the oil chamber 30A of the hydraulic cylinder 30 communicates with the drain tank and the oil chamber 30
The hydraulic pressure P _DEC of A decreases.

Conversely, when the signal pressure P _SOL is reduced, the spool 41 is displaced to the left in the drawing, so that the ports 43 G and 4
3F communicates to supply the operating pressure PL to the oil chamber 30A of the hydraulic cylinder 30 to increase the hydraulic pressure P _DEC applied to the oil chamber 30A, while increasing the drain port 4 according to the displacement of the land 42d.
Since the port 3D communicates with the port 3D, the hydraulic cylinder 30
The oil chamber 30B communicates with the drain tank, and the oil pressure P _INC of the oil chamber 30B decreases.

The power circulation mode clutch 9 is connected to a hydraulic actuator 62 driven by hydraulic pressure from a pressure control valve 61 as shown in FIG. When a signal pressure is supplied from the solenoid valve 60, a hydraulic pressure corresponding to the signal pressure is supplied to the hydraulic actuator 62 from the pressure control valve 61, and the power circulation mode clutch 9 is driven to be engaged, and the hydraulic pressure corresponding to the signal pressure is supplied. Fastening force is obtained. When the signal pressure is cut off, the oil pressure from the pressure control valve 61 is cut off, and the power circulation mode clutch 9 is released.

The direct connection mode clutch 10 is connected to a hydraulic actuator 72 driven by hydraulic pressure from a pressure control valve 71 as shown in FIG. When a signal pressure is supplied from the solenoid valve 70, a hydraulic pressure corresponding to the signal pressure is supplied from the pressure control valve 71 to the hydraulic actuator 72, and the direct connection mode clutch 10 is driven to be engaged, and the engagement corresponding to the signal pressure is performed. Power is gained. When the signal pressure is interrupted,
The hydraulic pressure from the pressure control valve 71 is shut off, and the direct connection mode clutch 10 is released.

The speed change control of the continuously variable transmission with an infinite speed ratio is performed by a speed change controller 100 mainly composed of a microcomputer as shown in FIG.

As means for detecting the operating state of the vehicle, a throttle opening sensor 101 for detecting a throttle opening TVO (or an accelerator pedal depression amount), a vehicle speed Vs
Speed sensor 102 for detecting the speed, shift selector 103 for detecting the shift position, and input shaft speed sensor 10 for detecting the speed of the unit input shaft 1 (engine speed).
4. A continuously variable transmission output shaft rotation number sensor 105 for detecting the rotation number of the output shaft 4 of the continuously variable transmission 2, and a tilt angle sensor 106 for detecting the tilt angle θ of the power roller 20 of the continuously variable transmission 2. ,
A vertical displacement detection sensor 107 for detecting the vertical displacement Y of the power roller 20 is provided.

Based on these detection signals, the transmission controller 100 determines the target transmission ratio and controls the tilt angle θ of the power roller of the continuously variable transmission 2 so as to achieve the target transmission ratio, that is, CVT control. The solenoid valve 53 for controlling the valve 40 and the switching between the power circulation mode and the direct connection mode are controlled, that is, the solenoid valve 60 and the direct connection mode clutch 10 for controlling the power circulation mode clutch 9.
Is controlled by the solenoid valve 70 which controls the solenoid valve.

In this case, at the time of the power circulation mode (at the time of forward movement)
The differential pressure ΔP = P _INC − between the oil pressures P _DEC and P _INC of the oil chambers 30A and 30B of the hydraulic cylinder 30 as shown in FIGS. 7 and 12 by the duty control of the solenoid valve 53.
By reducing P _DEC and tilting the power roller 20 to the smaller side of the tilt angle θ (the outer peripheral side of the output disk 22),
By shifting the gear to the Hi side, increasing the differential pressure ΔP = P _INC −P _DEC , and tilting the power roller 20 to the larger side of the tilt angle θ (the inner peripheral side of the output disk 22), Lo Shift to the side.

When the target gear ratio becomes equal to or more than a predetermined value,
The direct connection mode is entered from the mode switching point, and the duty control of the solenoid valve 53 causes the differential pressure ΔP = P = P of the oil pressures P _DEC and P _INC of the oil chambers 30A and 30B of the hydraulic cylinder 30 as shown in FIGS. _INC- P _DEC is decreased, and the power roller 20 is tilted to the larger side of the tilt angle θ (the outer peripheral side of the input disk 21), thereby shifting to the Hi side, and the differential pressure ΔP = P _INC − By increasing P _DEC and tilting the power roller 20 to the smaller side of the tilt angle θ (the inner peripheral side of the input disk 21), the shift to the Lo side is performed.

The switching between the power circulation mode and the direct connection mode is performed based on the flowcharts of FIGS.

As shown in FIG. 8, in step 1, the throttle opening TVO and the vehicle speed Vs are detected.

In step 2, it is determined whether or not the mode is switched based on the throttle opening TVO and the vehicle speed Vs.
When the speed ratio (or the tilt angle of the power roller 20 of the continuously variable transmission 2) is at the predetermined speed ratio (or the predetermined tilt angle) at the mode switching point, the mode switching control in step 3 is started.

FIG. 9 shows switching control from the power circulation mode to the direct connection mode. In step 11, the tilt angle θ of the power roller 20 and the vertical displacement Y of the power roller 20 are detected.

In step 12, based on the tilt angle θ of the power roller 20 and the vertical displacement Y of the power roller 20,
The oil chamber 30A of the hydraulic cylinder 30 is controlled so as to keep the tilt angle θ of the power roller 20 constant, that is, to keep the tilt angle θ constant.
Hydraulic P _DEC of the oil chamber 30B, the hydraulic P _INC differential pressure [Delta] P = P _INC
-P controls _DEC .

This constant control is based on the change of the tilt angle θ and the upper and lower
According to the displacement Y in the direction, the CVT control valve is calculated by the following equation (1).
Duty control value of solenoid valve 53 for controlling valve 40
duty Feedback correction of CVT.

Duty CVT = K1 × (θ ₀ −θ) + K2 (Y ₀ −Y) + duty CVT0 (1) where θ ₀ , Y ₀ , and duty CVT0 indicates a reference value.

In step 13, the direct connection mode clutch 1
0 engagement control is performed. In this case, the direct connection mode clutch 1
Previous duty control value duty of the solenoid valve 70 that controls 0 In DC, an additional value Δduty determined based on a required control time as in the following equation (2) DC is added and the current duty control value duty DC is obtained and the direct connection mode clutch 10
Is controlled (increase the fastening force).

Duty DC = duty DC + Δduty DC (2) In step 14, the change rate dθ is calculated from the previous detection value and the current detection value of the tilt angle θ of the power roller 20.

In step 15, it is determined whether the rate of change dθ of the tilt angle θ of the power roller 20 is smaller or larger than a predetermined value 0.

When the change rate dθ is larger than the predetermined value 0,
Since the tilt fluctuation of the power roller 20 is on the Lo side of the gear ratio, the process proceeds to steps 16 and 17.

In steps 16 and 17, the solenoid valve 7
With the duty control of 0, the operating oil pressure Pdc of the direct connection mode clutch 9 a is determined to be a predetermined hydraulic pressure Pdc, that is, whether the direct connection mode clutch 9 has reached a predetermined engagement force,
If not, the process returns to step 11.

When the change rate dθ is smaller than the predetermined value 0,
Since the tilt fluctuation of the power roller 20 is on the Hi side of the gear ratio, the process proceeds to step 20.

In step 20, the direct connection mode clutch 1
Control for decreasing the fastening force of 0 is performed. In this case, the previous duty control value duty of the solenoid valve 70 that controls the direct connection mode clutch 10 From DC, a required subtraction value Δduty as in the following equation (3) DC1 is subtracted to obtain the current duty control value duty DC is obtained, the direct connection mode clutch 10 is controlled to the disengagement side (the engagement force is reduced), and the process returns to step S11.

Duty DC = duty DC-Δduty DC1 (3) That is, when the direct-coupling mode clutch 10 is engaged, the force applied to the power roller 20 decreases. In this case, if the tilt fluctuation of the power roller 20 is on the Lo side of the gear ratio, The power roller 20 does not further tilt to the Lo side, and with the fastening thereof, the power roller 20 becomes Hi.
To return to the mode switching point.

If the power roller 20 has a tilt change of the gear ratio Hi, the further the direct-coupled mode clutch 10 is engaged, the more it shifts to the Hi side, and the power switch 20 moves away from the mode switching point. However, in this case, since the fastening force of the direct connection mode clutch 10 is reduced, the power roller 20 is tilted to the Lo side and returns to the mode switching point.

When the direct connection mode clutch 10 reaches a predetermined engagement force by the engagement control of the direct connection mode clutch 10, the process proceeds from Steps 16 and 17 to Steps 18 and 19, and the release control of the power circulation mode clutch 9 is performed.

This release control is based on the duty control value duty of the solenoid valve 60 for controlling the power circulation mode clutch 9.
From the PC, the required subtraction value Δduty is calculated as in the following equation (4). P
C is subtracted every control cycle, and the power circulation mode clutch 9
Release control to completely release the power circulation mode clutch 9 (duty PC <reference value duty PC0).

Duty PC = duty PC-Δduty PC (4) FIG. 11 shows the relationship between the duty control values of the solenoid valves 70 and 60 and the clutch pressures of the direct connection mode clutch 10 and the power circulation mode clutch 9.

As shown in FIG. 7, the engagement of the direct connection mode clutch 10 is started at a point A and completely engaged at a point B. Then, at point B, the power circulation mode clutch 9
Is released and completely released at point C. At this time, the pressure difference ΔP between the oil pressures P _DEC and P _INC of the oil chambers 30A and 30B of the hydraulic cylinder 30 is controlled by the constant control of the tilt angle.
= P _INC -P _DEC is controlled such that the control in the negative range is performed from the point A to the point B, and the differential pressure ΔP = 0 at the point B,
From point B to point C, control in a positive range is performed.

When switching from the power circulation mode to the direct connection mode by such control, even if the force applied to the power roller 20 decreases and the tilt angle of the power roller 20 fluctuates, the change is not changed. And the tilting angle of the power roller 20 is maintained at the tilt angle at the mode switching point.

Therefore, the switching to the direct connection mode is performed smoothly, and the shock at the time of the switching is sufficiently reduced.

FIG. 10 shows control for switching from the direct connection mode to the power circulation mode. In step 31, the tilt angle θ of the power roller 20 and the vertical displacement Y of the power roller 20 are detected.

In step 32, based on the tilt angle θ of the power roller 20 and the vertical displacement Y of the power roller 20,
The oil chamber 30A of the hydraulic cylinder 30 is controlled so as to keep the tilt angle θ of the power roller 20 constant, that is, to keep the tilt angle θ constant.
Hydraulic P _DEC of the oil chamber 30B, the hydraulic P _INC differential pressure [Delta] P = P _INC
-P controls _DEC .

This constant control is based on the change of the tilt angle θ and the upper and lower
According to the displacement Y in the direction, the CVT control valve is
Duty control value of solenoid valve 53 for controlling valve 40
duty Feedback correction of CVT.

In step 33, the power circulation mode crack
The fastening control of the switch 9 is performed. In this case, the power circulation mode
Previous duty of the solenoid valve 60 that controls the switch 9
Control value duty When the required control is applied to DC as in the previous equation (2)
Addition value Δduty determined based on the interval Add DC and add
Duty control value duty DC and determine the power circulation mode
The control is performed to increase the fastening force (the fastening force is increased).

In step 34, the rate of change d of the tilt angle θ of the power roller 20 is calculated from the previous detection value and the current detection value.
Calculate θ.

In step 35, it is determined whether the rate of change dθ of the tilt angle θ of the power roller 20 is smaller or larger than a predetermined value 0.

When the change rate dθ is smaller than the predetermined value 0,
Since the tilt fluctuation of the power roller 20 is on the Hi side of the gear ratio, the process proceeds to steps 36 and 37.

In steps 36 and 37, the solenoid valve 6
With the duty control of 0, the operating oil pressure Pdc of the power circulation mode clutch 10 It is determined whether a has reached the predetermined hydraulic pressure Pdc, that is, whether the power circulation mode clutch 10 has reached the predetermined engagement force. If not, the process returns to step 31.

When the change rate dθ is larger than the predetermined value 0,
Since the tilt change of the power roller 20 is on the Lo side of the gear ratio, the process proceeds to step S40.

In step 40, the control for decreasing the engaging force of the power circulation mode clutch 9 is performed. In this case, the previous duty control value duty of the solenoid valve 60 that controls the power circulation mode clutch 9 From DC, the required subtraction value Δduty as in the previous equation (3) DC1 is subtracted to obtain the current duty control value duty DC is obtained, the power circulation mode clutch 9 is controlled to the disengagement side (reducing the engagement force), and the process returns to step 31.

That is, when the power circulation mode clutch 9 is engaged, the force applied to the power roller 20 decreases. In this case, if the tilting fluctuation of the power roller 20 is on the Hi side of the gear ratio, the power The roller 20 does not further tilt to the Hi side, and the power roller 20 is tilted to the Lo side with the fastening thereof, and returns to the mode switching point.

Further, when the power roller 20 is tilted and fluctuates on the Lo side of the gear ratio, the clutch is further tilted to the Lo side when the power circulation mode clutch 9 is engaged, so that the power recirculation mode clutch 9 moves away from the mode switching point. However, in this case, since the fastening force of the power circulation mode clutch 9 is reduced, the power roller 20 is tilted to the Hi side and returns to the mode switching point.

When the power circulation mode clutch 9 reaches a predetermined engagement force by the engagement control of the power circulation mode clutch 9, steps 36 and 37 to steps 38 and 3 are performed.
The program then proceeds to 9 to perform release control of the direct connection mode clutch 10.

This release control is performed by the direct connection mode clutch 10
Control value duty of the solenoid valve 70 for controlling the
From the PC, the required subtraction value Δduty as in the above equation (4) P
C is subtracted for each control cycle, release control of the direct connection mode clutch 10 is performed, and the direct connection mode clutch 10 is completely released (duty PC <reference value duty PC0).

As shown in FIG. 7, the engagement of the power circulation mode clutch 9 is started at the point C and completely engaged at the point B. At the point B, the direct connection mode clutch 10
Is released and completely released at point A. At this time, the pressure difference ΔP between the oil pressures P _DEC and P _INC of the oil chambers 30A and 30B of the hydraulic cylinder 30 is controlled by the constant control of the tilt angle.
= P _INC -P _DEC is controlled so that a positive range control is performed from the point C to the point B and a differential pressure ΔP = 0 at the point B,
From point B to point A, control in a negative range is performed.

With such control, the switching is performed smoothly and the shock at the time of switching is sufficiently reduced in the case of switching from the direct connection mode to the power circulation mode, as in the case of switching from the power circulation mode to the direct connection mode. .

On the other hand, when the engagement control (increase control and decrease control of the engagement force) of the direct connection mode clutch 10 is performed when switching from the power circulation mode to the direct connection mode, and when the power is switched from the direct connection mode to the power circulation mode, During the engagement control (increase control and decrease control of the engagement force) of the circulation mode clutch 9, the input torque is controlled to be constant, that is, the output torque of the engine is controlled to be constant.

In this way, the fluctuation of the tilt angle of the power roller 20 at the time of mode switching is reduced, and the shock at the time of switching is further reduced.

Although the constant control of the tilt angle of the power roller is performed by the duty control of the solenoid valve 53, it may be mechanically performed in conjunction with the displacement of the piston 31 of the hydraulic cylinder 30.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a continuously variable transmission with an infinite speed ratio according to an embodiment;

FIG. 2 is a configuration diagram of a hydraulic cylinder and a control valve portion.

FIG. 3 is a hydraulic drive circuit diagram of a power circulation mode clutch.

FIG. 4 is a hydraulic drive circuit diagram of a direct connection mode clutch.

FIG. 5 is an explanatory diagram of a relationship between a force applied to a power roller and a differential pressure.

FIG. 6 is a control system diagram.

FIG. 7 is a diagram illustrating the relationship between 1 / speed change ratio and differential pressure.

FIG. 8 is a flowchart showing control contents.

FIG. 9 is a flowchart showing control contents.

FIG. 10 is a flowchart showing control contents.

FIG. 11 is a characteristic diagram of duty ratio and clutch pressure.

FIG. 12 is a diagram illustrating the relationship between the tilt angle of the power roller and the 1 / speed ratio.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unit input shaft 2 Continuously variable transmission 3 Constant transmission 4 Output shaft of continuously variable transmission 5 Planetary gear mechanism 5a Sun gear 5b Carrier 5c Ring gear 6 Unit output shaft 7 Transmission output gear 9 Power circulation mode clutch 10 Direct connection mode clutch 20 Power roller 21 Input disk 22 Output disk 23 Trunnion shaft 30A, 30B Oil chamber 31 Piston 40 CVT control valve 53 Solenoid valve 60 Solenoid valve 61 Pressure control valve 62 Hydraulic actuator 70 Solenoid valve 71 Pressure control valve 72 Hydraulic actuator 100 Transmission control controller 101 Throttle opening sensor 102 Vehicle speed sensor 103 Shift selector 104 Input shaft speed sensor 105 Continuously variable transmission output shaft speed sensor 106 Tilt angle sensor 107 Vertical displacement detection sensor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tatsuya Nagato 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa F-term (reference) in Nissan Motor Co., Ltd. 3D041 AA53 AC11 AC15 AC18 AD37 AD39 AE01 AE16 AE31 AE39 AF09 3J052 AA01 BA11 CA21 FA06 FB01 FB25 FB27 FB35 GC03 GC13 GC23 GC44 GC72 HA02 HA11 HA13 LA01

Claims (4)

[Claims] 1. A continuously variable transmission that continuously changes a gear ratio by tilting a power roller sandwiched between an input / output disk and a constant transmission are connected to a unit input shaft.
A continuously variable transmission with an infinitely variable transmission ratio in which the output shafts of the continuously variable transmission and the fixed transmission are connected to the unit output shaft via a planetary gear mechanism, a power circulation mode clutch and a direct coupling mode clutch, according to the operating conditions of the vehicle. Power to control the tilt angle of the power roller of the continuously variable transmission, and to drive the unit output shaft at a unit speed ratio according to the continuously variable transmission, the constant transmission, and the planetary gear mechanism by engaging the power circulation mode clutch. In a torque transmission force control device for an infinitely variable speed ratio transmission, comprising: a gear ratio control means for switching between a circulation mode and a direct coupling mode in which a unit output shaft is driven at a transmission ratio of a continuously variable transmission by engaging a direct coupling mode clutch. Means for detecting the tilt angle of the power roller of the continuously variable transmission; and, when switching between the power circulation mode and the direct connection mode, power in accordance with the tilt angle of the power roller. Torque transmitting force control apparatus for IVT, characterized in that a clutch force control means for controlling the engagement force of the direct mode clutch and the ring mode clutch. 2. The power control device according to claim 1, wherein when the power-circulation mode is switched from the power-circulation mode in the engaged state of the clutch to the direct-connection mode, the change rate of the tilt angle of the power roller is smaller than a predetermined value. 2. The torque of the continuously variable transmission with infinite transmission ratio according to claim 1, wherein the clutch engagement force is reduced, and control is performed to increase the engagement force of the direct connection mode clutch when the rate of change of the tilt angle is greater than a predetermined value. Transmission force control device. 3. The power transmission system according to claim 1, wherein the clutch force control means is configured to switch the power-coupling mode when the change rate of the tilt angle of the power roller is larger than a predetermined value when the direct-coupling mode is switched from the direct-coupling mode to the power-circulation mode. 2. The continuously variable transmission according to claim 1, wherein the clutch engagement force is reduced, and when the rate of change of the tilt angle is smaller than a predetermined value, control is performed to increase the engagement force of the power circulation mode clutch. 3. Torque transmission force control device. 4. The infinitely variable speed ratio continuously variable transmission according to claim 1, further comprising input torque control means for controlling input torque to be constant when engagement control of the power circulation mode clutch or the direct connection mode clutch is performed. Machine torque transmission force control device.