JP2000257686A - Toroidal type continuously variable transmission - Google Patents

Abstract

(57) [Problem] Toroidal continuously variable transmission capable of delicately controlling the vertical movement of each speed control piston provided in each trunnion in accordance with a shift state and improving synchronization stability. To provide. An input disk, an output disk disposed coaxially with the input disk, a trunnion (11) swinging about a pivot (10) twisted with respect to both central axes of the input disk and the output disk, This trunnion 1
In a toroidal-type continuously variable transmission having a power roller 10 supported by an input disk 1 and tiltably rotatable between an input disk and an output disk, each of the trunnions 11 is swung to perform shift control. A plurality of shift control pistons 23 are provided, and a control valve 27 for controlling the fluid pressure of each shift control piston 23 is independently provided for each shift control piston 23.
Is provided with a sensor 31 for detecting the axial displacement of the pivot 10.

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 for an automobile, a toroidal type continuously variable transmission applied to general industries or ships / aircrafts.

[0002]

2. Description of the Related Art Toroidal type continuously variable transmissions are known, for example, from Japanese Patent Application Laid-Open No. 2-163567, Japanese Patent No. 2568684, Japanese Patent Application Laid-Open No. 60-44657, and the like.

Japanese Patent Application Laid-Open No. Hei 2-163567 discloses a method for outputting a common control signal to hydraulic actuators provided corresponding to power rollers as a plurality of continuously variable transmission portions of a double-cavity toroidal type continuously variable transmission. A structure is disclosed in which a single control valve is provided for performing continuously variable transmission of a plurality of continuously variable transmission portions.

Japanese Patent No. 2568684 discloses a double-cavity toroidal type continuously variable transmission in which a common speed change control valve is provided in an oil chamber provided corresponding to a power roller as a plurality of continuously variable transmission portions. A structure is disclosed in which the vertical movement of a plurality of trunnions is mechanically linked by a link and a rod.

Japanese Patent Application Laid-Open No. Sho 60-44657 discloses that
An electromagnetic on-off valve is provided in a fluid pressure circuit communicating with a fluid pressure cylinder, which is a transmission means of a continuously variable transmission, and a port as a sensor for detecting the vertical movement and rotation of one of the plurality of trunnions. A structure provided with a tension meter is disclosed.

[0006]

Therefore, each of the cylinders has a structure in which the pressure (high pressure side and low pressure side) of a cylinder for swinging a plurality of trunnions is controlled by one control valve. Pressure cannot be precisely controlled.

Further, in the toroidal type continuously variable transmission, the power roller is displaced from the center of the input and output disks so that the power roller tilts to the contact point between the disk and the power roller (side slip). Is generated to perform a gear shift. More specifically, the trunnion supporting the power roller is moved up and down by the shift control piston to generate a side slip, and when the power roller is tilted to the target position, the shift control piston is returned to complete the shift. That is, the vertical movement of the power roller leads to the tilting of the power roller.

This movement is very sensitive, only 0.1
The power roller tilts with the movement of mm. Therefore, it is very important for a toroidal-type continuously variable transmission to operate a plurality of, for example, four, power rollers at the same tilt angle. Therefore, it is necessary to completely match the vertical movements of the four power rollers. There is. However, in Japanese Patent Application Laid-Open No. 2-163567, the pressure from one transmission control valve is transmitted to the four pistons so that the pressures of the four pistons are aligned and the vertical movements are matched. Since the precess cam mechanism that feeds back to the speed change control valve is provided only on one piston, other power rollers may move up and down due to disturbances such as vibrations, which may cause a speed change and a loss of synchronization.

Further, in Japanese Patent No. 2568684,
Although the four power rollers are linked in the vertical direction by mechanical linkage using links and rods, as described above, the speed change operation of the toroidal type continuously variable transmission is only 0.1.
An error in the vertical direction of mm is not allowed, and it is difficult to achieve such high accuracy with a mechanical linkage.

In particular, when the toroidal type continuously variable transmission is rotated at a high speed, the side slip at the contact point due to the vertical deviation is also increased, so that the sensitivity of the shift is further increased, and the four power rollers are synchronized. It is necessary to control the vertical movement more precisely.

In the toroidal type continuously variable transmission of the double cavity type, the input disks on the front side and the rear side have different shapes, so that the deformation state of the input disks on the front side and the rear side differs under a high load. However, since the contact point between the disk and the power roller is slightly different, it is necessary to slightly change the tilt angle of the power roller to match the rotation speed of each input / output disk on the front side and the rear side.
As described above, the control system cannot cope with such an operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a control valve for each shift control piston provided for each power roller, and to control each speed control piston. It is an object of the present invention to provide a toroidal-type continuously variable transmission capable of delicately controlling up-and-down movement in accordance with a shift state and improving synchronization stability.

[0013]

In order to achieve the above object, according to the present invention, there is provided an input disk, an output disk coaxially arranged with the input disk, and the input disk and the output disk. A plurality of trunnions swinging about a pivot portion having a twist with respect to both central axes, and a power roller supported by these trunnions and rotatably rolled between the input disk and the output disk. In the toroidal-type continuously variable transmission, a plurality of shift control pistons for performing shift control by swinging the respective trunnions are provided, and a control valve for performing fluid pressure control of each of the shift control pistons is controlled by the respective shift control. A detection means is provided independently for each piston, and detecting means for detecting an axial displacement of a pivot portion of each trunnion.

According to the above construction, since the vertical movement of the power roller leads to the tilting of the power roller, the amount of axial movement of the pivot portion of each trunnion is always detected by the sensor as the detecting means and inputted to the controller. Because
The relative deviation of the Axis of each trunnion is also read, and the controller controls the amount of axial movement of the Axis of each trunnion to be synchronized. In other words, even if any one of the trunnions causes a shift in the axial movement amount of the pivot portion due to disturbance, the shift control piston can be operated by the control valve of the corresponding trunnion to return the trunnion to the normal position.

[0015]

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

1 and 2 show a first embodiment. FIG. 1 is a longitudinal side view of a double-cavity toroidal type continuously variable transmission, and FIG. 2 is a control system diagram of a shift control piston.

First, the toroidal type continuously variable transmission will be described.
And a front-side output disk 3a, a rear-side input disk 2b, and a rear-side output disk 3b. The output disks 3a and 3b are rotatably supported via needle bearings 4, respectively, and the input disks 2a and 2b are attached to the shaft 1. On the other hand, they are connected by a ball spline, are integrally mounted in the rotation direction, and are slidably mounted in the axial direction.

A cam plate 5 is mounted on the rear side of the front input disk 2a by a bearing so as to be swingable concentrically with respect to the shaft 1. A plurality of cam plates 5 are provided between the cam plate 5 and the front input disk 2a. Rollers 6 are interposed between the input disks 2a. A loading cam-type pressing mechanism 7 for pressing the 2b against both output disks 3a and 3b is provided. The two output disks 3a, 3b are engaged with the output gear 9, and the two output disks 3a, 3b and the output gear 9 rotate in synchronization.

Between the input disks 2a, 2b and the output disks 3a, 3b, there are provided four trunnions 11 oscillating about a pivot 10, and a displacement shaft is provided at the center of each trunnion 11. 12 are provided. A power roller 13 is rotatably supported on each displacement shaft 12.
a, 2b and a traction portion in contact with the output disks 3a, 3b, and are rotatably pivoted between the input disks 2a, 2b and the output disks 3a, 3b.

Each trunnion 11 and the power roller 1
3, a power roller bearing 14 is provided.
The power roller bearing 14 allows the power roller 13 to rotate while supporting a load in the thrust direction applied to the power roller 13. The plurality of balls 15 of such a power roller bearing 14 are provided with an annular outer ring 16 provided on the trunnion 11 side and a power roller 13 as a rotating unit.
And is held by an annular holder 17 provided between them.

Further, each trunnion 11 comprises a main body flat portion 18 and the pivot portions 10 provided integrally at both ends of the main body flat portion 18, and each of the pivot portions 10 swings with respect to a support plate 21. It is movably supported, and the tilt angle of the displacement shaft 12 can be freely adjusted by swinging the trunnion 11.

Further, a drive rod 22 is connected to one end of each trunnion 11, and a speed change control piston 23 is independently provided on an outer peripheral surface of an intermediate portion of each drive rod 22. The shift control piston 23 includes a disc-shaped piston portion 24 and a cylinder portion 25 that houses the piston portion 24. The inside of the cylinder portion 25 is divided into a PH hydraulic chamber and a PL hydraulic chamber with the piston portion 24 interposed therebetween. It is partitioned.

The PH hydraulic pressure chamber and the PL hydraulic pressure chamber of the four shift control pistons 23 are connected to control valves 27 provided independently via oil passages 26, and each control valve 27 is connected to a common control valve 27. Pressure control valve 2
8 is connected to a hydraulic pump 29 as a pressure source. Further, each control valve 27 is controlled by a common controller 30, and information such as a vehicle speed, an accelerator opening, an engine speed, and the like of the vehicle is input to the controller 30.

Further, the driving rod 2 of each trunnion 11
2 is provided with a sensor 31 independently as a detecting means for detecting the amount of displacement of the trunnion 11 in the vertical direction (axial direction of the pivot 10) in the Y direction, and the detection signal of this sensor 31 is input to the controller 30. It has become so. The sensor 31 may be provided on the piston portion 24 of the shift control piston 23, and the sensor 31 needs to have a resolution of at least 0.05 mm or less.

The front input disk 2a is provided with a rotation speed sensor 32 for detecting the input rotation speed, and the front output disk 2b is provided with a rotation speed sensor 33 for detecting the output rotation speed. Sensor 32, 33
Is input to the controller 30.

According to the toroidal type continuously variable transmission configured as described above, the rotation transmitted from the driving source such as the engine to the pressing device 7 is transmitted to the front input disk 2a and the rear input disk 2b. You. Double input disk 2
The rotations of the output disks 3a, 3b are transmitted to the two output disks 3a, 3b via the power roller 13.
Is taken out from the output gear 9.

In order to change the rotational speed ratio between the input side and the output side, a pair of shift control pistons 23 on the front side are used.
Are displaced in directions opposite to each other, and the pair of shift control pistons 23 on the rear side are also displaced in directions opposite to each other. A pair of front and rear trunnions 11 are displaced in opposite directions in accordance with the displacement of each shift control piston 23. As a result, the direction of the tangential force acting on the contact portion between the peripheral surface of each power roller 13 and the inner peripheral surfaces of both input disks 2 and both output disks 3 changes, and with this change in the direction of the force. As a result, the trunnions 11 swing in opposite directions about the pivot 10 pivotally supported by the support plate 21.

That is, by removing the power roller 13 from the center of both input disks 2a, 2b and both output disks 3a, 3b, the input / output disks 2a, 2b, 3a, 3b
A shift is performed by generating a side slip at a contact point between the power roller 13 and the power roller 13 in such a direction that the power roller 13 tilts. More specifically, the trunnion 11 supporting the power roller 13 is moved up and down by the shift control piston 23 to generate a side slip. When the power roller 13 is tilted to the target position, the shift control piston 23 is returned to end the shift. . That is, since the vertical movement of the power roller 13 leads to the tilting of the power roller 13, the displacement amount of the pivot portion 10 of each trunnion 11 in the Y direction is always detected by the sensor 31 and input to the controller 30.
The relative deviation of the pivot 10 of each trunnion 11 is also read, and the controller 30 controls so that the axial movement of the pivot 10 of each trunnion 11 is synchronized. That is, even when the displacement amount of the pivot portion 10 in the Y direction is displaced due to disturbance in one of the trunnions 11, the shift control piston 23 is operated by the control valve 27 of the corresponding trunnion 11 to bring the trunnion 11 to the normal position. return.

The power roller 13 corresponding to the speed ratio
The rotational angle of the input disk 2a and the output disk 3a is read by the rotational speed sensors 32 and 33 to calculate the gear ratio, and the rotational angle is determined from the transmission ratio. When performing a gear shift, the required amount of displacement in the Y direction of the power roller 13 is calculated from the deviation of the current gear ratio, the target gear ratio, and the target gear speed, and a signal is sent to each control valve 27. Move to and start tilting. When the power roller 13 is tilted to the target shift position, the position in the Y direction is returned to the original position, and the shift is completed.

In the first embodiment, the rotation speeds of the input / output disks 2a, 3a are measured by the rotation speed sensors 32, 3
3, the tilt angle is calculated and the tilt angle is calculated. However, any one of the shift control piston 23 and the sensor 31 provided on the trunnion 11 may have a function of detecting the tilt angle. Further, each shift control piston 23
Alternatively, if all the sensors 31 provided on each trunnion 11 have a function of detecting the tilt angle, the controller 30 can monitor the synchronization of each power roller 13 not only in the Y direction but also in the tilt direction. Therefore, more reliable synchronization stability can be obtained.

In the first embodiment, the double-cavity toroidal type continuously variable transmission has been described. However, a single-cavity type or a three-roller type in which three power rollers are arranged in one cavity can be similarly applied. .

[0032]

As described above, according to the invention as set forth in the claims, a control valve is provided for each shift control piston provided corresponding to each power roller, and the vertical movement of each speed control piston is shifted. This has the effect that the control can be delicately controlled in accordance with the timing and the synchronization stability can be enhanced.

[Brief description of the drawings]

FIG. 1 is a vertical side view of a toroidal-type continuously variable transmission according to a first embodiment of the present invention.

FIG. 2 is a control system diagram of a shift control piston of the embodiment.

[Explanation of symbols]

 2a, 2b: input disk 3a, 3b: output disk 10: pivot 11: trunnion 13: power roller 23: shift control piston 27: controller valve 30: controller 31: sensor (detection means)

Continued on the front page F term (reference) 3J051 AA04 BA03 BE09 CA05 EA08 ED11 FA02

Claims (1)

[Claims] 1. An input disk, an output disk coaxially arranged with the input disk, and a plurality of trunnions swinging about a pivot that is twisted with respect to both central axes of the input disk and the output disk. And a power roller supported by these trunnions and rotatably rolled between the input disk and the output disk. A toroidal-type continuously variable transmission, And a control valve for controlling the fluid pressure of each of the shift control pistons is provided independently for each of the shift control pistons, and the axial displacement of the pivot portion of each of the trunnions is controlled. A toroidal-type continuously variable transmission characterized by comprising a detecting means for detecting.