JPH11223257A - Torque transmitting force control device for gear ratio infinite continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily control a power roller to a position difficult to tilt by providing a means for estimating the vertical position of the power roller whose tilting angle is never changed, and performing a control so as to change a signal pressure on the basis of the difference between the estimated vertical position and a detected vertical position. SOLUTION: This device is provided with a hydraulic cylinder 30 having a piston 21 for receiving the torque transmitting force acting on a power roller 20 according to the differential pressure between first and second oil chambers 30A, 30B, and the oil pressure of each oil chamber 30A, 30B is controlled by a control valve 40. The control valve 40 displaces a spool axially according to the signal pressure guided to the end surface of the spool to allow each oil chamber 30A, 30B to communicate with the original pressure oil passage or a drain tank according to a prescribed directional displacement of the spool. At that time, the signal pressure is regulated by controlling an actuator 82 through a control device 80 on the basis of the detection result of the vertical position of the power roller 20 detected by a sensor 81.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a torque transmitting force control device for a continuously variable transmission with an infinite transmission ratio, which is employed in vehicles and the like.

[0002]

2. Description of the Related Art A belt-type or toroidal-type continuously variable transmission has been known as a transmission for a vehicle. SUMMARY OF THE INVENTION A continuously variable transmission having an infinitely variable transmission ratio is known which is configured to control a transmission ratio to infinity by combining a continuously variable transmission with a planetary gear mechanism as disclosed in JP-A-42428. I have.

As shown in FIG. 1, this conventional infinitely variable speed continuously variable transmission continuously changes the speed ratio to a unit input shaft 1 of an infinitely variable speed continuously variable transmission coupled to an engine. A possible continuously variable transmission 2 is connected in parallel with a speed reducer 3 '(constituted by gears 3'a, 3'b, 3'c) having a constant speed ratio, and their output shafts. 4,3'c
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 3'c of the speed reducer 3 'is connected to the low resume clutch 8
It is connected to the carrier 5b of the planetary gear mechanism 5 via a power circulation mode clutch 8 (hereinafter, referred to as a power circulation mode clutch 8).

A continuously variable transmission output shaft 4 connected to the sun gear 5a is connected to a unit output which is an output shaft of an infinitely variable speed ratio transmission via a direct clutch 9 (hereinafter referred to as a directly connected mode clutch 9). Connected to the shaft 6,
The ring gear 5c of the planetary gear mechanism 5 also has the unit output shaft 6
Is joined to.

In such a continuously variable transmission with an infinite transmission ratio,
By connecting the power circulation mode clutch 8 and disconnecting the direct connection mode clutch 9, the total reduction ratio is infinite from a negative value to a positive value according to the speed ratio of the continuously variable transmission 2 and the speed reducer 3 '. And the power-recirculation mode clutch 8 is cut off while the direct-connection mode clutch 9 is closed.
To selectively use a direct connection state (hereinafter referred to as a direct connection mode) in which a speed ratio according to a product of a speed ratio of the continuously variable transmission 2 and a speed ratio of the continuously variable transmission output gear trains 2a and 4a is obtained. be able to.

As shown in FIG. 1, the continuously variable transmission 2 is of a toroidal type in which two sets of input disks 21 and output disks 22 press the power roller 20 respectively.
The power roller 20 of the continuously variable transmission 2 has a lower end supported by a hydraulic cylinder 30 as shown in FIG.
It is supported by a trunnion shaft 23 that can rotate around the axis.

The hydraulic cylinder 30 is defined by a piston 31 into upper and lower oil chambers 30A and 30B.
By increasing the oil pressure of the oil chamber 30A as the second oil chamber, the torque transmission force of the power roller 20 decreases, while increasing the oil pressure of the oil chamber 30B as the first oil chamber increases the torque of the power roller 20. The transmission force increases, and the oil chambers 30A, 3
By adjusting the differential pressure of 0B, the torque transmission force is continuously controlled.

As shown in FIG. 3, the hydraulic cylinder 30
It is driven according to the hydraulic pressure from a control valve 40 having a spool 41 that is slidable in the axial direction.

Both ends 42a, 42e of the spool 41
The three lands 42b, 42c, 42d are formed at predetermined intervals therebetween, and between the right end 42e in the figure and the inner periphery of the control valve 40 (hereinafter simply referred to as the inner periphery). A spring 44 for urging the spool 41 toward the left side in the figure is interposed, and a signal pressure Psol from a solenoid valve (not shown) is applied to an inner circumference toward an end face of the left end 42a in the figure. The supply signal pressure port 43A is opened, and the spool 41 is urged to the right in the drawing against the spring 44 according to the signal pressure Psol.

The left end 42a of the spool 41
The oil chamber 3 below the hydraulic cylinder 30 is provided on the inner circumference facing between the oil cylinder 3 and the land 42b and the land 42d.
Ports 43B and 43G communicating with the spool 0A are formed, and an oil chamber above the hydraulic cylinder 30 is provided on the inner periphery facing the right end 42e of the spool 41 and the land 42d and between the land 42b and the land 42c. Ports 43D and 43I communicating with 30B are formed respectively.

A line pressure port 43E communicating with a source pressure oil passage from a hydraulic supply (not shown) is opened on the inner periphery facing the land 42c, and the port 43D or 43G is opened in accordance with the displacement of the land 42c. Line pressure P to one of them
1 is supplied.

On the other hand, drain ports 43C and 43H communicating with a drain tank (not shown) are opened on the inner periphery facing the lands 42b and 42d.
One of the ports 43D or 43G is connected to the drain tank according to the displacement of 2d. These lands and ports constitute differential pressure adjusting means for the oil chamber 30A on the decreasing side and the oil chamber 30B on the increasing side of the torque transmitting force of the hydraulic cylinder 30.

A drain port 43J is opened on the inner periphery facing the end 42e of the spool 41, and hydraulic oil is discharged.

Further, the ends 42a, 42 of the spool 41
e is set equal to the outer diameter of each land 42b to 42d.
Are set equal to each other, and the outer diameter of the land is set to be larger than the outer diameter of the end portion.

Here, when the signal pressure Psol is increased, the spool 41 is displaced to the right in the drawing, so that the port 43E
And 43D communicate with each other to supply the line pressure Pl to the oil chamber 30B of the hydraulic cylinder 30, and to apply a hydraulic pressure Pinc applied to the oil chamber 30B.
While the drain port 43H communicates with the port 43G in accordance with the displacement of the land 42d, the oil chamber 30A of the hydraulic cylinder 30 communicates with the tank, the oil pressure Pdec of the oil chamber 30A decreases, and the differential pressure Pinc − The torque transmitting force of the power roller 20 that balances with Pdec increases.

Conversely, when the signal pressure Psol is decreased, the spool 41 is displaced to the left in the drawing, and the ports 43G and 43E communicate with each other to supply the line pressure Pl to the oil chamber 30A of the hydraulic cylinder 30, and the oil pressure is reduced. While the oil pressure Pdec applied to the chamber 30A increases, the drain port 43C and the port 43D communicate with each other in accordance with the displacement of the land 42b. Therefore, the oil chamber 30B of the hydraulic cylinder 30 communicates with the tank, and the oil pressure Pinc of the oil chamber 30B decreases. However, the torque transmitting force of the power roller 20 that balances with the differential pressure Pinc-Pdec decreases.

Therefore, the torque transmitting force of the power roller 20 can be controlled by adjusting the differential pressure between the oil pressures Pdec and Pinc of the oil chambers 30A and 30B according to the increase and decrease of the signal pressure Psol.

The oil pressures Pdec, P of the oil chambers 30A, 30B
When the signal pressure Psol is changed from the state where the differential pressure of inc is balanced with the torque transmitting force of the power roller 20, the power roller 20 is displaced upward or downward from the balanced position as shown in FIG. As a result, the power roller 20 is tilted around the trunnion shaft 23, and is configured to shift to a position where the differential pressure between the oil pressures Pdec and Pinc balances the torque transmitting force of the power roller 20.

[0019]

However, in the conventional torque transmission force control apparatus for a continuously variable transmission with an infinite speed ratio, the vertical position of the power roller where the tilt angle does not change is the force applied to the power roller. Of the power roller cannot be properly controlled in the vertical position of the power roller without a change in the tilt angle, and control stability cannot be secured. Was.

The present invention has been made in view of the above circumstances, and has as its object to provide a torque transmission force of an infinitely variable speed ratio transmission capable of appropriately controlling an intended transmission torque. It is intended to provide a control device.

[0021]

According to the present invention, there is provided a continuously variable transmission and a fixed transmission connected to a unit input shaft, and an output shaft of the continuously variable transmission. A planetary gear mechanism comprising a sun gear connected to the unit, a carrier connected to the output shaft of the fixed transmission, and a ring gear connected to the unit output shaft, and a power circulation mode interposed in a transmission path from the input shaft of the unit to the carrier. A clutch, a direct-coupled mode clutch interposed in a transmission path from an output shaft of the continuously variable transmission to a unit output shaft, and an input disk and an output disk having a toroidal groove. A power roller capable of variably setting the contact state of the power roller, and a piston receiving a torque transmitting force acting on the power roller according to a differential pressure between a hydraulic pressure of the first oil chamber and a hydraulic pressure of the second oil chamber. And a control valve for controlling the hydraulic pressure of the first and second oil chambers, and an actuator for controlling the signal pressure Psol acting on the end face of the spool. A signal pressure port for guiding a signal pressure Psol is provided on an end surface of the spool so as to accommodate the axially displaceable spool and to bias the spool in the axial direction. While the first oil chamber communicates with the original pressure oil passage and the second oil chamber communicates with the drain tank, the second oil chamber communicates with the second oil chamber according to displacement of the spool in a direction opposite to the predetermined direction. The technical concept is a torque transmission control device for an infinitely variable speed ratio transmission, which is configured to communicate with the primary pressure oil passage and to communicate between the first oil chamber and the drain tank. , Its vertical position Comprising means for detecting, based on the detected vertical position, and characterized by being configured to vary the signal pressure Psol.

In the present invention, the torque transmission control device includes means for estimating the vertical position of the power roller where the tilt angle does not change, and determining the vertical position obtained by the estimating means and the detected vertical position of the power roller. By controlling the signal pressure Psol to change based on the difference, the control target value can be determined in consideration of the direction of the force applied to the power roller, and the control can be performed to a position where the tilt change is more difficult.

In the present invention, the torque transmission control device includes an input torque estimating means, a power transmission mode discriminating means, and a means for detecting a tilt angle. By calculating the vertical position of the roller and controlling the signal pressure Psol to change based on the calculated value and the detected vertical position of the power roller, the rate of change in tilt due to deformation of a component or the like becomes zero. Can be corrected, it is possible to control to a position where tilt change is more difficult.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment of the invention shown in the accompanying drawings.

The infinitely variable speed ratio continuously variable transmission according to one embodiment of the present invention is basically a toroidal type continuously variable transmission like the conventional infinitely variable speed ratio transmission shown in FIG. The input gear 3a and the gear 3b constitute a constant transmission 3, and the counter gear 40a is meshed between the output gear 2a and the gear 4a of the continuously variable transmission 2, and Step transmission output gear train 40 (2a, 40a, 4a)
Is composed.

As shown in FIG. 4, the power roller 20 of the continuously variable transmission 2 is supported at its lower end by a trunnion shaft 23 supported by a hydraulic cylinder 30 and rotatable around its axis.

When the trunnion shaft 23 changes in the axial direction, the displacement in the vertical direction and the change in the tilt angle are detected by the sensor 81, and the displacement and the change are converted into electric signals and input to the control device 80. The actuator 82 is controlled based on the input signal. That is, the electric signal is converted into a hydraulic pressure by the actuator 82, and the control valve 40 is operated.
The hydraulic pressures Pinc and Pdec are controlled.

Next, the operation of the infinitely variable speed ratio continuously variable transmission according to this embodiment will be described.

The pressure difference between the hydraulic chambers 30A and 30B and the input roller 21 and the output disk 22
The position of the power roller 20 in the trunnion axis direction (hereinafter, referred to as the vertical direction) is determined by the balance of the forces acting on zero. From the state where the balance is maintained, the power roller 20 changes in the vertical direction due to the change in the input torque, the tilt angle changes, and the speed ratio of the continuously variable transmission changes.

At this time, the vertical displacement and the tilt angle change are detected by the sensor 81, and based on the detection results,
The control operation of the actuator 82 is performed by performing feedback control so that the deviation between the rotation axis of the power roller 20 and the rotation axis of the input disk 21 becomes zero, and the vertical displacement without tilting occurs.

In practice, the sensor 81 converts the displacement Y of the power roller 20 into a voltage value Vy. The converted voltage value Vy is converted to a digital value, and the control device 80 determines the output voltage V to the actuator 82 from the converted digital value Dvy.

This output voltage V is given by V = Vtgt + f (D
vy). Here, f () is a function, and an appropriate feedback amount is given.

As shown in FIG. 10, this Vtgt is given by the relationship between the actuator drive voltage V and the differential pressure ΔP and the differential pressure ΔP ′ determined from the torque to be transmitted by the transmission (this differential pressure ΔP The method for calculating 'is not specifically described.) This pressure difference ΔP ′ is applied to the map shown in FIG. 10 to determine Vtgt.

The pressure corresponding to the voltage V is output from the actuator 82 and becomes a command pressure to the control valve 40, and the differential pressure between the hydraulic pressures Pinc and Pdec is controlled and controlled.

Thus, the control valve 40 adjusts the differential pressure between the hydraulic chambers 30A and 30B so that the vertical displacement is at a position where the displacement can be balanced.

FIG. 5 shows a control flowchart. In step 51, the input torque Tin is calculated. In this case, the input torque becomes the output torque of the engine directly.

As shown in FIG. 6, the engine speed Ne and the throttle opening T
The engine torque (input torque) is calculated from the VO from the engine performance diagram shown in FIG. 7 (step 62).

In step 52, an appropriate target vertical displacement Ytgt is calculated based on the input torque Tin and the operation mode (power circulation mode or direct connection mode). This calculating means is shown in FIG.

In step 81, the tilt angle φ and the throttle opening TVO are detected. In step 82, the power transmission mode (operation mode) is determined. Although not specifically described herein, the control device 80 can determine whether the power circulation mode clutch is engaged or the direct connection clutch is engaged.

The result of the determination is used. If the result is the power circulation mode, the variable b is set to “1”. If not, the variable b is set to “0”.
Set to. At the same time, a forward / backward determination is made in step 83. This refers to the value of the tilt angle φ detected in step 81, and determines whether the tilt angle is a forward side or a reverse side from φ0 (a tilt angle that becomes geared neutral).

When it is determined in step 83 that the vehicle is moving forward, the variable a is set to "1".
Is set to “0”.

At the same time, in step 84, power ON / OFF determination is performed. The determination of the power ON / OFF may be determined based on, for example, a read voltage value of the throttle opening, or may be determined by ON / OFF of an accelerator switch. If it is determined that the power is ON, the variable c is set to "1" in step 810, and the power O is set.
If determined to be FF, the variable c is set to "0" in step 811. Using the values of the variables a, b, and c calculated in this manner, the variable d
Is calculated as d = 4a + 2b + c.

If the calculated value is one of 1, 3, 5, and 6, Ytgt is set to "Ya" in step 816.
Set to. For other values, set Ytgt to "Y
b ”.

These Ya and Yb are set differently depending on the direction of the force applied to the power roller 20, as shown in FIG.

Next, in step 53, step 5
Based on the value of the input torque Tin calculated in step 1, Yf is set with reference to the map shown in FIG.

This Yf is, for example, Ytgt = Ya + Y
f, taking into account the deformation of the disk due to the force acting on the power roller 20, and adding to Ya and Yb, the vertical displacement of the power roller 20 in which the tilting motion of the power roller 20 does not occur is considered. Can be estimated.

By performing such control, torque transmission can be stably controlled, and controllability can be greatly improved.

[0048]

According to the first aspect of the present invention, the torque transmission force control apparatus for a continuously variable transmission with an infinite transmission ratio estimates the magnitude of the force applied to the power roller by estimating the input torque as described above. , The direction of the force applied to the power roller can be estimated from the difference between the power circulation mode and the direct connection mode and the forward / backward movement in the power circulation mode, so that the tilt angle due to the change in the direction and magnitude of the force applied to the power roller Can be set as the target vertical displacement, so that intended control can be performed.

According to the second aspect of the present invention, the control target value can be determined in consideration of the direction of the force applied to the power roller.

Further, according to the third aspect of the present invention, the position where the rate of change in tilt due to deformation of a component or the like becomes zero can be corrected, so that control can be performed to a position where tilt change is more difficult. it can.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view of a continuously variable transmission with an infinite gear ratio.

FIG. 2 is a schematic configuration explanatory view showing a torque transmission force control device of the continuously variable transmission.

FIG. 3 is a schematic configuration diagram of a control valve of the continuously variable transmission.

FIG. 4 is an explanatory diagram showing a schematic configuration of a power roller of the continuously variable transmission.

FIG. 5 is a control flowchart of the continuously variable transmission.

FIG. 6 is a flowchart for calculating an input torque in the continuously variable transmission.

FIG. 7 is an engine performance diagram of the continuously variable transmission.

FIG. 8 is a control flowchart showing a procedure for calculating a target vertical displacement in the continuously variable transmission.

FIG. 9 is a map showing a relationship between torque and Y displacement in the continuously variable transmission.

FIG. 10 is a map showing a relationship between an actuator drive voltage and a differential pressure in the continuously variable transmission.

[Explanation of symbols]

Reference Signs List 1 unit input shaft 2 continuously variable transmission 3 constant transmission 4 continuously variable transmission output shaft 5 planetary gear mechanism 6 transmission output shaft 7 transmission output gear 8 power circulation mode clutch 9 direct mode clutch 20 power roller 21 input disk 22 Output disk 23 Trunnion shaft 30 Hydraulic actuator 30A, 30B Oil chamber 31 Piston 40 Control valve 41 Spool 42a, 42e End 42b, 42c, 42d Land 43A Signal pressure port 43B, 43D, 43E, 43F, 43G, 43I port 43C, 43H , 43J Drain port 44 Spring 80 Control device 81 Sensor 82 Actuator

Claims (3)

[Claims] 1. A continuously variable transmission and a constant transmission respectively connected to a unit input shaft, a sun gear connected to an output shaft of the continuously variable transmission, and a carrier and a unit output shaft connected to an output shaft of the constant transmission. A planetary gear mechanism consisting of a ring gear connected to the power transmission mode clutch disposed on a transmission path from the input shaft of the unit to the carrier;
A direct-coupled mode clutch interposed in the transmission path from the output shaft of the continuously variable transmission to the unit output shaft, and a contact state between the input disk and the output disk having a toroidal groove, which are sandwiched between these disks. A power cylinder capable of variably setting a hydraulic cylinder, a hydraulic cylinder including a piston receiving a torque transmitting force acting on the power roller in accordance with a pressure difference between a hydraulic pressure of the first oil chamber and a hydraulic pressure of the second oil chamber, First
And a control valve for controlling the oil pressure in the second oil chamber, and an actuator for controlling the signal pressure Psol acting on the end face of the spool. The control valve accommodates a spool which can be displaced in the axial direction. A signal pressure port for guiding a signal pressure Psol is provided on an end face of the spool so as to bias the spool in the axial direction. In addition, while the second oil chamber communicates with the drain tank,
A gear ratio configured to communicate the second oil chamber with the original pressure oil passage and communicate the first oil chamber with the drain tank in accordance with the displacement of the spool in a direction opposite to the predetermined direction. In the torque transmission control device for an infinitely variable transmission, the power roller has means for detecting its vertical position, and is configured to change the signal pressure Psol based on the detected vertical position. A torque transmission control device for a continuously variable transmission with an infinite transmission ratio. 2. A torque transmission control device for a continuously variable transmission with an infinite speed ratio according to claim 1, wherein the estimating means obtains the vertical position of the power roller whose tilt angle does not change. A torque transmission control device for a continuously variable transmission with an infinite transmission ratio, wherein the signal pressure Psol is controlled to be changed based on the difference between the vertical position and the detected vertical position of the power roller. 3. The torque transmission control device for an infinitely variable speed ratio transmission according to claim 2, further comprising: an input torque estimating unit, a power transmission mode determining unit, and a unit for detecting a tilt angle. The vertical position of the power roller at which the tilt angle does not change is calculated from these values, and control is performed to change the signal pressure Psol based on the calculated value and the detected vertical position of the power roller. Torque transmission control device for infinitely variable speed ratio transmission.