JPH06174029A - Toroidal type continuously variable transmission - Google Patents

Abstract

PURPOSE:To realize a light weight of a piston holding member while securing the cylindricity of piston operating oil chambers when the movement of a trunnion in the axial direction is hydraulically controlled, in a toroidal type CVT. CONSTITUTION:A pair of piston operating oil chambers 51a and 51b of a first toroidal type CVT unit, and a pair of piston operating oil chambers 51c and 51d of a second toroidal type CVT are formed by the cylinders 52a to 52d of a piston holding member 30. The pair of cylinders 52a and 52b, and the pair of cylinders 52c and 52d are combined by ribs 90 and 91 to combine them each other and extending their ends in the tangent direction. To the piston holding member 30, other ribs 93 and 94 orthogonal to the ribs 90 and 91 are also provided. A link post 31 to hold a pair of trunnions is extended parallel to the other ribs 93 and 94, and connected to the ribs 90 and 91.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a toroidal type continuously variable transmission, and more particularly to weight reduction thereof.

[0002]

2. Description of the Related Art Conventionally, as a toroidal type continuously variable transmission, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-92859, an input disk and an output disk having a toroidal surface, and a space between the toroidal surfaces of the disks. And a pair of trunnions supporting the respective power rollers, the output shaft is connected to the output disc, and power is transmitted from the input disc through the power roller to the output disc. By transmitting the power to the output shaft and moving both trunnions in the axial direction, the tilt angle of each power roller can be changed and the gear ratio between both disks can be adjusted steplessly. It is known that

By the way, in the toroidal type continuously variable transmission as described above, as disclosed in the publication, the axial movement of the trunnion is controlled by hydraulic pressure, and the pair of actuators for controlling the movement of each trunnion are hydraulically controlled. Each has a piston. Each of these hydraulic pistons is arranged in a piston working oil chamber, and each working oil chamber is formed in a plate-shaped piston support member having a predetermined thickness.

[0004]

However, in the above-mentioned prior art, when the piston support member is viewed from the viewpoint of the force acting on the piston support member, the torques that the pair of power rollers receive are opposite to each other. , The directions of the hydraulic pressures to be applied to the pair of piston working oil chambers are also opposite to each other, one piston working oil chamber receives an upward force, the other piston working oil chamber receives a downward force, and the piston support member Since it deforms flexibly in the thickness direction, it is desirable to form the piston support member thick from the viewpoint of effectively suppressing this deformation, but from the viewpoint of reducing the weight of the toroidal type continuously variable transmission, the piston operating oil There is a drawback that the weight becomes heavy because the other parts except the chamber become thicker.

The present invention has been made in view of the above problems, and an object thereof is to increase the rigidity of a piston support member when hydraulically controlling axial movement of a pair of trunnions of a toroidal type continuously variable transmission. It is to secure and effectively suppress or prevent the flexural deformation while reducing the weight of the piston support member.

[0006]

In order to achieve the above object, the present invention reduces the weight of the piston support member and provides ribs at appropriate positions of the piston support member in consideration of the force acting on the piston working oil chamber. The configuration is provided.

That is, the concrete means for solving the problems of the first aspect of the present invention is to provide an input disk, an output disk, a pair of tiltable power rollers arranged between the two disks, and support each power roller. With a trunnion to
A toroidal type continuously variable transmission that transmits power from the input disk to the output disk through the power roller and changes the tilt angle of the power roller by axial movement of the trunnion to continuously change the gear ratio. set to target. Then, on the premise that a pair of actuators having pistons for controlling the axial movement of the trunnions is provided, the cylinder of the piston support member having a pair of cylindrical portions forming the hydraulic oil chambers of the pistons of the actuators. A rib that connects the piston hydraulic oil chambers and extends in the tangential direction of the cylindrical portion is provided around the portion.

Further, in the invention described in claim 2, the invention described in claim 1 is limited, and further, with respect to the circumference of the cylindrical portion,
Another rib that is orthogonal to the rib and extends in the tangential direction of the cylindrical portion is provided.

In addition, in the invention described in claim 3, the invention described in claim 2 is limited, and a post for supporting a pair of trunnions is arranged between a pair of cylindrical parts, and the post is
The ribs extending in the direction of connecting the piston hydraulic oil chambers are connected more firmly than the other ribs.

[0010]

With the above construction, in the invention according to claim 1,
In the piston support member, since the pair of cylindrical portions are connected to each other by the ribs, even if each of the cylindrical portions receives hydraulic pressure in opposite directions from the piston working oil chamber, it is difficult to deform in the acting direction of the hydraulic pressure. The flexural deformation of the piston support member is effectively suppressed or prevented. Therefore, it is not necessary to form the piston support member with a thick member, and the weight can be reduced.

Moreover, since the ribs extend in the tangential direction of each cylindrical portion and the compressive force and the tensile force via the ribs act in the tangential direction of the cylindrical portions, the ribs are provided radially and the central axes of both cylindrical portions are arranged. As compared with the case where the upper part is connected by a rib, the strain deformation of each piston working oil chamber is effectively suppressed, and the cylindricity of the piston working oil chamber is maintained well.

According to the second aspect of the present invention, since the other ribs are arranged on the piston support member in a direction orthogonal to the direction connecting the pair of cylindrical portions, the power plant is bent in this orthogonal direction. Even when a force is applied, the bending deformation of the piston support member due to this bending force is effectively suppressed.

Further, according to the third aspect of the invention, when there is an imbalance between the forces transmitted from the pair of power rollers, the difference force between the forces is transmitted to the post via the pair of trunnions. However, even in this case, the post is firmly connected to the rib extending in the tangential direction in the direction connecting the piston working oil chambers, that is, the rib that is difficult to deform the piston working oil chamber. The cylindricity of the piston hydraulic oil chamber is kept good.

[0014]

As described above, according to the toroidal type continuously variable transmission of the invention described in claim 1, when the axial movement of the trunnion is hydraulically controlled, a pair of pistons are actuated in the piston support member. Since the oil chambers are connected by the ribs extending in the tangential direction of the cylindrical portion, the piston supporting member is effective while ensuring good cylindricity of each piston working oil chamber and effectively suppressing or preventing the flexural deformation of the piston supporting member. Can be made lighter.

According to the second aspect of the present invention, the other rib is provided on the piston support member in a direction orthogonal to the direction in which the piston working oil chambers are connected. Even when the bending force of the power plant acts, the bending deformation of the piston support member due to the bending force can be effectively suppressed or prevented.

Further, according to the third aspect of the present invention, the posts supporting the pair of trunnions are more firmly connected to the ribs in the direction connecting both piston working oil chambers than the ribs orthogonal to the ribs. Even if a force corresponding to the difference in force between the pair of power rollers acts on the post, it is possible to effectively suppress and prevent the flexural deformation of the piston support member while ensuring good cylindricity of the piston working oil chamber. Produce an effect.

[0017]

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

1 and 2 show a toroidal type continuously variable transmission according to the present invention, 1 is an output shaft, 2 is a first toroidal type continuously variable transmission unit arranged on the output shaft 1, 3 Is a second toroidal type continuously variable transmission unit arranged on the right side of FIG. 1 of the first transmission unit.

The first toroidal type continuously variable transmission unit 2 has an input disk 5 rotatably supported by an output shaft 1.
And an output disc 6 arranged to face the input disc 5 on the left side of FIG. 1, and the output disc 6 is spline-coupled to the output shaft 1. A toroidal surface 5 formed between the disks 5 and 6 is formed between the disks 5 and 6.
A pair of power rollers 7 and 7 are disposed across and in contact with a and 6a.

Similarly, the second toroidal type continuously variable transmission unit 3 includes an input disk 9 similar to the above, an output disk 10 arranged on the right side of the input disk 9 in FIG. 10 toroidal surfaces 9a, 10a, and a pair of power rollers 11, 11 that are in contact with each other. The input disk 9 is arranged such that the back surface thereof faces the back surface of the input disk 5 of the first continuously variable transmission unit 2, that is, the side surface opposite to the toroidal surface 5a with which the power roller 7 contacts. The pair of input disks 5 and 9 are located inside, and the pair of output disks 6 and 10 are located outside.

An intermediate disk 15 is arranged in a space formed between the rear surfaces of the pair of input disks 5 and 9 and the intermediate disk 15 and both input disks 5 and 5.
A plurality of loading cams 16, 16 ... Are arranged in the circumferential direction between each of them. Further, power is applied to the outer periphery of the intermediate disk 15 by the pair of input disks 5, 9
1 is integrally formed with a power transmission gear 18 that is a helical gear that transmits power to the vehicle, and an engine (not shown) is arranged on the left side of the first toroidal type continuously variable transmission unit 2 in FIG. Engine power is transmitted from an input shaft (not shown). On the other hand, the intermediate disc 15 and the input discs 5 and 9 each have a cam groove formed on the side surface facing the loading cams 16 ... Both of these cam grooves have an intermediate disc 15 and input discs 5, 9
When the and are relatively rotated, the loading cams 16 are engaged with the input disks 5 and 9 to increase the pressing force as the relative displacement increases. Therefore, engine power is transmitted from the power transmission gear 18 and the intermediate disc 15 to the output discs 6 and 10 through the loading cams 16 ..., the input discs 5 and 9, and the power rollers 7 and 11 in order, and then to the output shaft 1. Then, the output shaft 1 is taken out from the right end in FIG.

The intermediate disk 15 is divided into two parts in the axial direction, and a disc spring 19 for urging the two is separated between the two, and the disc spring 19 provides a low torque. Even during transmission, the loading cams 16 ...
Is urged toward the corresponding output disks 6 and 10 to apply pressure so as to generate a predetermined pressing force.

Each of the toroidal type continuously variable transmission units 2,
The power rollers 7 and 11 of 3 are respectively eccentric shafts 20 and 2
A pair of trunnions 21, 2 arranged in the vertical direction through 0
1 is rotatably supported. A shaft member 22 arranged in the vertical direction is fixedly arranged at the lower end of each trunnion 21, and the trunnion 21 is displaced in the vertical direction by displacing the shaft member 22 in the vertical direction. , 11 are tilted, whereby the contact points at which the power rollers 7, 11 come into contact with the input / output disks 5, 6, 9, 10 are changed to change the speed ratio steplessly. There is. The upper end of each trunnion 21 is supported by a bolt 29 attached to a link post 26 formed in the transmission casing 25 in order to allow the rotation of each trunnion 21 around the axis due to the tilting of the power rollers 7, 11. The member 27 is supported by a spherical bearing 28 so as to be rotatable in the axial direction, and the lower end portion thereof has an upper housing 3 described later.
It is rotatably supported by a spherical bearing 33 by a support member 32 attached to a link post 31 formed in 0 by a bolt 34.

As shown in FIG. 2, the lower end of the shaft member 22 is supported by a bearing 41 rotatably and vertically movably in the recesses 40 of the middle and lower housings 37 and 38 arranged below the upper housing 30. In addition, an actuator 45 for moving the shaft member 22 up and down is connected to a substantially central position of the shaft member 22. The actuator 45 includes a casing 47 fixed to the transmission casing 25 with bolts 46 and an inwardly projecting portion 47a formed on the casing 47, and a center portion of the actuator 45 is fitted to the shaft member 22. The piston 48 is inserted and fixed. The piston 48 and the protruding portion 47a of the casing 47 form a pair of hydraulic chambers 49, 50 in the vertical direction, and the hydraulic pressure is supplied to the upper hydraulic chamber 49 to move the shaft member 22 upward in FIG. The shaft member 22 is moved downward in FIG. 2 by supplying hydraulic pressure to the lower hydraulic chamber 50.

The above middle and lower housings 37, 38
Includes a shift control device 60 that controls the supply of hydraulic oil to the hydraulic chambers 49 and 50 of each actuator 45 to shift gears.
Are placed. That is, in the middle housing 37,
Supply oil passage 6 to which oil pressure is supplied from an oil pressure source (not shown)
1 and a first oil passage 62 and a second oil passage 63, which communicate with the hydraulic chambers 49 and 50 of the actuators 45, respectively. A hydraulic control valve 65 is arranged in the lower housing 38. The valve 65 includes a sleeve 67 slidably disposed in the valve body, and a sleeve 67 slidably disposed in the valve body, with an outer wall of a hollow portion formed by horizontally drilling a central portion of the lower housing 38 as a valve body. And the spool 68 disposed in the. In the sleeve 67, the supply oil passage 61 and the first and second oil passages 6 are provided.
First to third ports 67a to 67c corresponding to 2, 63
And the oil supply passage 61 is formed in accordance with the movement of the sleeve 67.
Oil from the first port 67a to the first oil passage 62 via the recess of the spool 68 and the second port 67b, or to the spool 6
It is configured to communicate with the second oil passage 63 through the recessed portion 8 and the third port 67c.

In the vicinity of the left end of FIG. 2 of the sleeve 67,
A pin member 70 is connected to the pin member 70, and a rotary shaft 72a of a stepping motor 72 attached to a vertical wall portion of an oil pan 79 arranged at a lower portion of the transmission casing 25 via a drive member 71 arranged in a sleeve 67. The sleeve 67 is connected and slides the sleeve 67 in the left-right direction in FIG. 2 according to the rotation of the motor 72.

Further, at the right end of FIG. 2 of the spool 68,
A feedback mechanism 80 that feeds back the tilting of the power roller 7 is arranged. The feedback mechanism 80
Is a recess cam 81 fixedly arranged on the shaft member 22 of the trunnion 21 of the second continuously variable transmission unit 3, a first arm 82 whose tip engages an inclined surface 81a formed on the recess cam 81, and the first arm 82. Is rotatably supported, a second arm 84 which is rotatably supported by the rotation 83 and engages with the right end of the spool 68 of the hydraulic control valve 65 in FIG. 2, and the spool 68 in FIG.
A compression coil spring 85 is provided between the left side and the pin member 70, and the shaft member 22 is moved in the vertical direction by the oil supply to the actuator 45 in accordance with the movement of the sleeve 67. When tilted, the first of the feedback mechanism 80 is moved according to the vertical movement of the shaft member 22.
The second arm 82, 84 rotates clockwise or counterclockwise, and the spool 68 moves in the same direction as the sleeve 67, so that the supply oil passage 61 and the first or second oil passage communicating with the supply oil passage 61. The communication with 62 and 63 is cut off, and the oil supply to the actuator 45 is stopped when the tilted position of the power roller 7 reaches the target position.

Next, the characteristic part of the present invention will be described. Figure 3
Shows an upper housing 30, which functions as a piston support member. In the upper housing 30, the shaft members 2 of the four trunnions 21 ...
Four cylindrical hydraulic oil chambers 51a to 51d into which the pistons 48 respectively inserted through 2 are inserted are bored, and the hydraulic oil chambers 51a to 51d are respectively formed into four wall surfaces surrounding each of them. It is formed by the cylindrical portions 52a to 52d.

In the upper housing (piston support member) 30 shown in FIG. 3, two corresponding trunnions 21 and 21 of the first toroidal type continuously variable transmission unit 2 are provided.
The cylindrical portions 52a, 52b are surrounded by the cylindrical portions 52a, 52b.
Two ribs 90, 90 connecting the a and 52b are arranged so as to extend in the tangential direction (that is, the vertical direction in the drawing) at the left and right end positions of the cylindrical parts 52a, 52b in the drawing. Similarly, the second
The two ribs 91, 91 connecting the two cylindrical portions 52c, 52d are also provided around the two cylindrical portions 52c, 52c corresponding to the pair of trunnions 21, 21 of the toroidal type continuously variable transmission unit 3. The cylindrical portions 52c and 52d are arranged so as to extend in the tangential direction at the left and right end positions in the figure.

Further, the piston supporting member 30 is provided with other ribs 93, 94 extending in a direction orthogonal to the ribs 90, 91, that is, in the left-right direction in FIG. The one rib 93 is arranged so as to extend in the tangential direction at the lower end position of each of the cylindrical portions 52b and 52d so as to connect the cylindrical portion 52b and the cylindrical portion 52d. Also, the other rib 94
Are arranged so as to connect the cylindrical portions 52a and 52c so as to extend in the tangential direction at the upper end positions of the respective cylindrical portions 52a and 52c in the figure.

In addition, the pair of cylindrical portions 52a, 52b
Between and between the other pair of cylindrical portions 52c and 52d,
Link posts 31 and 31 for mounting the trunnion support member 32 are respectively located, and the link posts 31 and 31 are provided.
3 has a structure in which it is firmly connected to the ribs 90 and 91 via other ribs 95 and 95 extending in the left-right direction in FIG. 3, and is not connected to the other ribs 93 and 94.

Therefore, in the above embodiment, for example, when the input disks 5 and 9 rotate in the direction shown by the broken line arrow in FIG. 2 and the output shaft 1 rotates in the direction shown by the solid line in FIG. The power roller 7 receives an upward force as shown in the figure, and the power roller 7 located on the right side of FIG. 2 receives a downward force as shown in the figure. Therefore, in order to hold each power roller 7, 7 at that position, the actuator 45 on the left side of FIG. 2 is supplied with high hydraulic pressure to the lower oil chamber 50, and the actuator 45 on the right side of FIG. The hydraulic pressure is supplied, and as a result, the upper housing (piston support member) 30 receives a force as indicated by a broken line in the figure with the supply of each of the high hydraulic pressures, and is bent and deformed vertically. However, in the piston support member 30, both the cylindrical portions 52a, 5 forming the both piston working chambers 51a, 51b are formed.
Since the 2b is connected by the two ribs 90, 90, the bending deformation is effectively suppressed or prevented.

Moreover, the ribs 90, 90 extend in the tangential direction at the end positions of the cylindrical portions 52a, 52b as shown in FIG. 3, and the compressive force and the tensile force pass through the ribs 90 and the cylindrical portion 52a. , 52b acts tangentially on the ends,
Compared with the case where ribs are arranged on the line connecting the center positions of the cylindrical portions 52a and 52b, the piston working chambers 51a and 5a
The deformation of 1b is effectively suppressed, and its cylindricity can be maintained well. Above, the first toroidal type continuously variable transmission unit 2
However, the same applies to the second toroidal-type continuously variable transmission unit 3.

Further, an engine is arranged on the left side of the continuously variable transmission in FIG. 1, and the entire power plant including the engine and the continuously variable transmission is centered around the area between the continuously variable transmission and the engine. Although the bending force acts up and down, the piston support member 30 is provided with other ribs 93 and 94 which are orthogonal to the ribs 90 and 91 and resists the bending force. It is also possible to suppress or prevent flexural deformation due to the above bending force.

In addition, when there is a difference in transmission force between the pair of power rollers 7 and 7 or between the other pair of power rollers 11 and 11, the difference force is the force of the pair of trunnions 2.
1 and 21 acts on the corresponding link post 31, but the post 31 is connected via another rib 95 to the ribs 90, 91 connecting the pair of piston working chambers 51a, 51b or 51c, 51d. Therefore, the displacement can be effectively suppressed. In that case, the force acting on the post 31 is
Since it does not act on the central portion of each of the pair of piston working chambers 51a, 51b or 51c, 51d from the direction orthogonal to the rib 95, the cylindricity of the piston working chambers 51a is maintained well.

FIG. 4 and FIG. 5 show a modification of the invention described in claim 3, and in the above embodiment, ribs 90 extending in the direction connecting the link posts 31 to the pair of piston working chambers are provided.
Instead of connecting only to the ribs 91, the ribs 90, 91
In addition to this, the ribs 93 and 94 orthogonal to this are also weakly connected.

That is, as shown in FIGS. 4 and 5, the piston support member 30 'has each link post 31 and a pair of corresponding piston working chambers 51a, 51b or 51.
Another rib 96 ... Is provided in the direction connecting the central portions of the c and 51d. As shown in FIG. 4, each of the ribs 96 ... Is formed to have a height lower than that of the other rib 95. With this configuration, the displacement of the link post 31 is mainly caused by the other rib 9.
It is configured to be suppressed by 5 ...

Therefore, in this modification, a part of the force acting on the link post 31 acts toward the center of the piston working chamber 51a through the rib 96, but most of the remaining force acts on the rib 95 and the rib. Since it acts in the tangential direction of the piston working chambers 51a ... After passing through 90 and 91, the deformation of each piston working chamber 51a ... Is sufficiently suppressed and the cylindricity can be maintained well, as in the above embodiment.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a toroidal type continuously variable transmission as viewed from the side.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a cross-sectional view of a main part of a continuously variable transmission showing a modified example of a link post reinforcing structure.

FIG. 5 is a view corresponding to FIG. 3 showing the modified example.

[Explanation of symbols]

 2,3 Toroidal type continuously variable transmission unit 5,9 Input disk 6,10 Output disk 7,11 Power roller 21 Trunnion 30 Piston support member 31 Link post (post) 45 Actuator 48 Piston 51a to 51d Hydraulic oil chamber 52a to 52d Cylinder Parts 90, 91 Ribs 93, 94 Other ribs

Claims (3)

[Claims] 1. An input disk, an output disk, a pair of tiltable power rollers arranged between the disks, and a trunnion for supporting each of the power rollers,
A toroidal type continuously variable transmission that transmits power from the input disk to the output disk through the power roller and changes the tilt angle of the power roller by axial movement of the trunnion to continuously change the gear ratio. There is provided a pair of actuators having pistons for controlling the axial movement of the trunnions, and a piston supporting member having a pair of cylinders forming a hydraulic oil chamber of the pistons of the actuators is provided around the cylinders. A toroidal type continuously variable transmission, characterized in that a rib is provided which connects the two piston hydraulic oil chambers and extends in the tangential direction of the cylindrical portion. 2. The toroidal type continuously variable transmission according to claim 1, wherein another rib that is orthogonal to the rib and extends in a tangential direction of the cylindrical portion is provided around the cylindrical portion. 3. A post for supporting a pair of trunnions is arranged between the pair of cylindrical portions, and the post is stronger than other ribs with respect to a rib extending in a direction connecting both piston hydraulic oil chambers. The toroidal-type continuously variable transmission according to claim 2, wherein the toroidal-type continuously variable transmission is connected to the.