JPS61119864A - Toroidal type continuously variable transmission - Google Patents

Abstract

PURPOSE:To reduce a discharge loss, by a method wherein a back pressure in a hydraulic working chamber on the driving side is applied on the back pressure chamber of a regulator valve, and a device is formed so that a line pressure can be automatically regulated in proportion to input torque. CONSTITUTION:Since a hydraulic working chamber 17a on the driving side is communicated with a back pressure chamber 33 of a regulator valve 3, an increase in an oil pressure in the hydraulic working chamber 17a with the increase in input torque is transmitted to a back pressure chamber 33 of a regulator valve 3, and a spool 32 is pressed in a direction in which a port 37 is closed. As a result, a line pressure in an oil passage 61 is increased and a high oil pressure proportioning input torque is applied on the hydraulic working chamber 17a on the driving side, and this eliminates the need to maintain a line pressure at a value exceeding maximum input torque.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention provides a toroidal non-R transmission in which a power roller is placed in pressure contact between input and output disks, and which can perform stepless speed change by changing the inclination of the power roller. It is related to.

Prior art and its problems As described in Japanese Patent Application Laid-Open No. 58-54262,
By operating the support that rotatably supports the power roller in its own axial direction (direction perpendicular to the power roller axis), the direction of the tangential force acting on the power roller is changed, and this tangential force is A toroidal continuously variable transmission is known that changes the inclination of a power roller depending on a force component.

In this case, hydraulic chambers are provided at both ends of the support, a control valve is provided between the hydraulic chamber and the hydraulic pressure supply source, and the control valve switches the oil path to each hydraulic chamber. , turn on the line pressure acting on the hydraulic working chamber,
0FPtallL, the support is actuated in the axial direction.

By the way, as the human output disk rotates, the support body is urged in the rotational direction of the input disk, so a large back pressure acts on the drive side hydraulic chamber facing the rotation direction of the input disk. The pressure increases as the input torque on the input disk increases. Therefore, in order to quickly move the support to the desired shift position, the line pressure acting on the drive-side hydraulic chamber must be set to a value that exceeds the maximum input torque. However, if the line pressure is set high, Since a high line pressure always acts even when the input torque is low, there is a problem in that the discharge loss of the oil pump increases, resulting in poor fuel efficiency.

Purpose of the Invention The present invention has been made in view of the problems of the prior art.
The purpose is to provide a toroidal continuously variable transmission that can regulate line pressure to the minimum necessary in response to input torque and reduce oil pump discharge loss as much as possible.

Structure of the Invention In order to achieve the above object, the present invention provides a regierator valve between the control pulp and the hydraulic pressure supply source,
A drive side hydraulic chamber facing the rotational direction of the input disk is communicated with the back pressure chamber of the regierator valve.

In other words, by applying the back pressure of the drive side hydraulic operation chamber to the back pressure chamber of the regierator valve, the line pressure can be automatically regulated in proportion to the input torque, and as a result, the input torque is reduced. When it is low, the line pressure can also be kept low, and discharge loss can be reduced as much as possible.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of a toroidal continuously variable transmission according to the present invention, where l is a troy, a dull transmission section, 2 is a control pulp, 3 is a regiator valve, and 4 and 5 are hydraulic supply sources. This consists of an oil tank and an oil pump.

Two power rollers 12 are disposed in pressure contact between an input disk 11 and an output disk (not shown) facing each other in the toroidal transmission section 1, and each power roller 12 is connected to It is rotatably supported by a support body 14.

Pistons 15a and 15b, which are slidable in cylinders 16a and 16b, are connected to both ends of the support body 14.
The support body 14 is movable together with the piston in the axial direction (in the vertical direction in the figure) and is rotatable around its own axis. Further, hydraulic chambers 17a and 17b are formed inside the cylinders tea and 16b, and the side facing the rotation direction of the input disk 110 (indicated by an arrow in the figure) is the drive-side hydraulic chamber. Because of the operation 117, the opposite side is the non-drive side hydraulic operation 1i17b.

The control pulp 2 includes a sleeve 22 slidably inserted into a pulp body 21 and a spool 23 slidably inserted into the sleeve 22. The sleeve 22 is actuated in the axial direction by an actuator 24 of a speed ratio control device, and the left end of the spool 23 is constantly in contact with a brisis cam 25 by the biasing force of a spring 26. is connected to the upper end of the support 14 of the support 1
4 and moves the spool 23 forward and backward.

The regiator valve 3 has a spool 32 inserted into a valve body 31 so as to be freely advanced and retracted, and this spool 32 is biased to the right by a spring 34 provided at a back pressure 'M33. A central port 35 of the regierator valve 3 is connected to the discharge side of the oil pump 5, and a port 36 adjacent to this port 35 is connected to the suction side of the oil pump 5. The central port 35 is connected to the central port 27 of the control pulp 2 via an oil passage 61.
An oil passage 62 branched from the oil passage 61
is connected to the right end port 37 of the regierator valve 3. The back pressure chamber 33 of the regierator valve 3 is connected to the oil passage 63
Via the drive-side hydraulic chamber 17 of the toroidal transmission section l.
a, and further connected to the left port 28 of the control pulp 2 via an oil path 64 branched from the oil path 63. On the other hand, the non-drive side hydraulic operation 1t'rb is connected to the right port 29 of the control pulp 2 by the oil passage 65.
It is connected to the.

In the toroidal continuously variable transmission configured as described above, when the engine is started, the oil pump 5 is driven, and the hydraulic pressure generated by the oil pump 5 is sent to the central port 35 of the regulator pulp 3. This oil pressure acts on the right end of the spool 32 through the oil passage 62, and moves the spool 32 to the left against the spring 34. As a result, the ports 35 and 36 communicate with each other, and are connected to the suction side of the oil pump 5. Therefore, the oil pressure in the oil passage 61 connected to the central port 35 is maintained in a state where this oil pressure and the spring force of the spring 34 are balanced (line pressure).

Here, when changing the gear ratio of the toroidal transmission section 1, the actuator 24 moves the sleeve 22 of the control pulp 2, for example, to the right in the figure. As a result, the ports 27 and 2B are communicated, and the line pressure is activated via the oil passages 61 and 64 on the drive side! 171 and communicated with the non-drive side hydraulic actuation 1i17b via the oil passage 65, the port 29 is connected to the hole 23 provided in the spool 23.
drained through a. Therefore, the hydraulic pressure in the drive-side hydraulic chamber 17a increases, and the left support 14 moves upward, and the right support 14 moves downward. Along with this, the direction of the tangential force applied to the power roller 12 changes, so the left power roller 12 and support 14 rotate clockwise, and the right power roller 12 and support 14 rotate to the left. Rotate in the rotational direction. In other words, a toroidal transmission! shifts to the speed increasing side. Then, the Brisis cam 25, which rotates together with the left support 14, rotates counterclockwise and pushes the spool 23 to the right until the port 2B is closed. The gear ratio is controlled up to and maintained at this gear ratio. The above operation is described in the above-mentioned Japanese Patent Application Laid-Open No. 58-5426.
This is the same as that described in Publication No. 2.

When the input torque applied to the input disk 11 increases during the above-mentioned speed-changing operation, the support '14 is pushed to the opposite side to the above-mentioned operation, that is, the left support 14 is pushed downward, and the right support 14 is pushed upward. Therefore, it takes time to reach the desired gear ratio, or it becomes impossible to maintain this gear ratio. Therefore, it is necessary to maintain the line pressure at a high value that does not hinder operation even when the maximum input torque is applied, which is a cause of oil pump discharge loss.

In the present invention, since the drive-side hydraulic IE 17a is communicated with the back pressure 3433 of the regierator valve 3 via the oil passage 63, an increase in the oil pressure in the drive-side hydraulic chamber 17m due to an increase in input torque is caused by The pressure is instantaneously transmitted to the back pressure chamber 33 of the regierator valve 3, pushing the spool 32 to the right, that is, in the direction of closing the port 37. As a result, oil line 6
The line pressure in 1 increases, and the drive side hydraulic operation* l 7
A high hydraulic pressure proportional to the human torque is applied to a. In other words, the line pressure is regulated to always exceed the input torque due to the action of the back pressure chamber 33 of the regierator valve 3, so there is no need to maintain the line pressure at a value that always exceeds the maximum input torque. .

FIG. 2 is a diagram showing the pressure regulating operation of the regulator pulp 3, where the solid line A shows the change in back pressure due to the input torque acting on the drive side hydraulic actuation 117-, and the dashed line B shows the change in line pressure. ing. The hydraulic pressure difference between the solid line A and the dashed line B is given by the spring force of the spring 34 of the regulator pulp 3. In this way, even if the input torque changes, the line pressure is always regulated higher than the back pressure caused by the manual torque, so there is no problem in controlling the toroidal transmission section 1, and when the input torque is small, the line pressure Since the discharge loss of the oil pump can be kept low, the discharge loss of the oil pump can be reduced as much as possible.

In addition, the broken line C in the second m is the back pressure of the regulator pulp 3!
! This is a case where the area of 33 is made smaller than other parts, and the oil pressure difference with the solid line A becomes smaller as the speed moves toward the high speed side.

In this way, losses during high-speed running can be further reduced.

Effects of the Invention As is clear from the above explanation, according to the present invention, the back pressure of the drive side hydraulic working chamber is applied to the back pressure chamber of the regulator pulp, so the line pressure is automatically regulated in proportion to the input torque. This allows the discharge loss of the oil pump to be reduced as much as possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the toroidal continuously variable transmission according to the present invention, and FIG. 2m is a diagram showing the pressure regulating operation of the regiator valve. 1... Toroidal transmission section, 11... Input disk,
12... Power roller, 14... Support body, 17a.
... Drive side hydraulic working chamber, 2... Control pulp,
3...Regierator valve, 33...Back pressure chamber, 34
...Spring, 5...Oil pump, 63...
Oil road.

Claims (1)

[Claims] (1) An input/output disk, a power roller placed in pressure contact between the input/output disks, a support that rotatably supports the power roller, is movable in the axial direction and rotatable around the axis, and a support In a toroidal continuously variable transmission, which is connected to both ends of the body and includes a hydraulic chamber for operating the support body in the axial direction, and a control valve that controls hydraulic pressure to the hydraulic chamber, the control valve 1. A toroidal continuously variable transmission characterized in that a regulator valve is provided between the input disc and a hydraulic pressure supply source, and a drive-side hydraulic operating chamber facing the rotational direction of the input disk is communicated with a back pressure chamber of the regulator valve.