JPH10281269A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate constantly optimum thrust in spite of a change of an operation state and to ensure compatibility between transmission efficiency and durability at a high-dimension. SOLUTION: A press device 40 to press a disc 2 on the input side against a power roller is formed such that a mechanical type first press device 41 and a hydraulic type second press device 42 are arranged in juxtaposition. An oil pressure to operate the second press device 42 is controlled by a control valve 59. The control valve 59 regulates an oil pressure by means of a command signal from a controller 60 to input a detecting signal to represent the number of revolution of engine, an accelerator opening, a car speed, and the temperature of traction oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The toroidal-type continuously variable transmission according to the present invention is used as an automatic transmission for an automobile.

[0002]

2. Description of the Related Art The use of a toroidal type continuously variable transmission as schematically shown in FIGS. This toroidal type continuously variable transmission supports an input side disk (first disk) 2 concentrically with an input shaft 1 as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. Sho 62-71465. An output disk (second disk) 4 is fixed to an end of the output shaft 3 which is arranged concentrically with the output shaft. Inside a casing containing the toroidal-type continuously variable transmission, a trunnion 6 swinging around pivots 5, 5 which are twisted with respect to the input shaft 1 and the output shaft 3,
6 are provided.

Each of the trunnions 6, 6 has the pivots 5, 5 on the outer surfaces of both ends. In addition, the trunnions 6, 6 support the base end of the displacement shafts 7, 7 at the center thereof, and the trunnions 6, 6 are pivoted about the pivots 5, 5 so that the trunnions 6, 6 are pivoted. The inclination angles of the displacement shafts 7, 7 can be adjusted freely. Each trunnion 6,
Power rollers 8, 8 are rotatably supported around displacement shafts 7, 7 supported by 6, respectively. These power rollers 8 are sandwiched between the input side and output side disks 2, 4.

The inner surfaces 2a and 4a of the input and output disks 2 and 4 facing each other have a cross section of
A circular arc about the pivot 5 forms a concave surface obtained by rotating the arc about the input shaft 1 and the output shaft 3. The peripheral surfaces 8a, 8a of the power rollers 8, 8 formed on the spherical convex surfaces are in contact with the inner side surfaces 2a, 4a.

[0005] A loading device 9 of a loading cam type is provided between the input shaft 1 and the input disk 2, and the input disk 2 is directed toward the output disk 4 by the pressing device 9. Pressing. This pressing device 9
Is a cam plate 10 that rotates together with the input shaft 1 and a retainer 11
(For example, four) rollers 12 held by
12. A cam surface 13 which is an uneven surface extending in the circumferential direction is formed on one side surface (the left side surface in FIGS. 5 to 6) of the cam plate 10, and an outer side surface of the input side disk 2 (the right side in FIGS. 5 to 6). Surface) also has a similar cam surface 14 formed thereon. The plurality of rollers 12, 12 are rotatably supported around a radial axis with respect to the center of the input shaft 1.

When the cam plate 10 rotates with the rotation of the input shaft 1 during use of the toroidal type continuously variable transmission configured as described above, the cam surface 13 causes the plurality of rollers 12, 12 to rotate.
The input side disk 2 is pressed against the cam surface 14 on the outer side. As a result, the input side disk 2 is pressed by the power rollers 8 and 8 and at the same time, the pair of cam surfaces 13 and
The input side disk 2 rotates based on the pressing between the roller 14 and the plurality of rollers 12. Then, the rotation of the input side disk 2 is controlled by the power rollers 8,
The output shaft 3 is transmitted to the output side disk 4 via the output disk 8 to rotate the output shaft 3 fixed to the output side disk 4.

When the rotational speed ratio (speed change ratio) between the input shaft 1 and the output shaft 3 is changed. First, when deceleration between the input shaft 1 and the output shaft 3 is performed, the pivots 5 and 5 are centered. The trunnions 6, 6 are swung so that the peripheral surfaces 8a, 8a of the power rollers 8, 8 are located near the center of the inner surface 2a of the input disk 2 and the inner surface of the output disk 4 as shown in FIG. 4a
The respective displacement shafts 7, 7 are tilted so as to abut against the outer peripheral portions of the respective shafts.

Conversely, when increasing the speed, the trunnions 6, 6 are swung about the pivots 5, 5, and the peripheral surfaces 8a, 8a of the power rollers 8, 8 are shown in FIG. As described above, a portion near the outer periphery of the inner surface 2a of the input disk 2 and a portion near the center of the inner surface 4a of the output disk 4
The respective displacement shafts 7, 7 are inclined so as to abut each other.
If the inclination angle of each of the displacement shafts 7, 7 is set between those in FIGS. 5 and 6, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3.

FIGS. 7 and 8 show Japanese Utility Model Application No. 63-6929.
3 shows a more specific toroidal-type continuously variable transmission described in Microfilm No. 3 (Japanese Utility Model Laid-Open No. 1-173552). Input disk 2 and output disk 4
Is rotatably supported around a circular input shaft 15 as a rotating shaft via needle bearings 16 and 16, respectively. The cam plate 10 is connected to the end of the input shaft 15 (FIG. 7).
(Left end of the disk) is spline-engaged with the outer peripheral surface, and is prevented from moving in a direction away from the input side disk 2 by the flange portion 17. The cam plate 10 and the rollers 12, 1
2, the loading cam type pressing device 9 for rotating the input side disk 2 while pressing the input side disk 2 toward the output side disk 4 based on the rotation of the input shaft 15. An output gear 18 is connected to the output disk 4 by keys 19, 19 so that the output disk 4 and the output gear 18 rotate in synchronization.

The pivots 5, 5 provided at both ends of the pair of trunnions 6, 6 swing on the pair of support plates 20, 20 in the axial direction (the front-back direction in FIG. 7 and the left-right direction in FIG. 8). It is supported so that it can be displaced. Then, displacement shafts 7, 7 are provided in circular holes 23, 23 formed in the middle portions of the trunnions 6, 6, respectively.
I support. These displacement shafts 7, 7 are parallel and eccentric to each other with respect to support shafts 21, 21 and pivot shafts 22, 2,
2 respectively. Each of the support shaft portions 21,
21 is swingably supported inside the circular holes 23, 23 via radial needle bearings 24, 24.
The power rollers 8, 8 are rotatably supported around the pivot shafts 22, 22 via radial rolling bearings such as radial needle bearings 25, 25.

The pair of displacement shafts 7, 7 are provided at positions opposite to each other by 180 degrees with respect to the input shaft 15. Also, each of the pivot shaft portions 22, 22 of each of these displacement shafts 7, 7
The direction of eccentricity with respect to each of the support shaft portions 21 is the same direction (the left and right direction in FIG. 8) with respect to the rotation direction of the input side and output side disks 2, 4. Also, the eccentric direction is the direction in which the input shaft 15 is disposed (the left-right direction in FIG.
(Front and back directions). Therefore, the power rollers 8 are supported so as to be slightly displaceable in the direction in which the input shaft 15 is disposed. As a result, due to the dimensional accuracy of each component, elastic deformation during power transmission, etc., the power rollers 8, 8 move in the axial direction of the input shaft 15 (the left-right direction in FIG. 7, the front and back sides in FIG. 8). Direction), the displacement can be absorbed without applying excessive force to each component.

Further, between the outer surface of each of the power rollers 8, 8 and the inner surface of the middle portion of each of the trunnions 6, 6, thrust ball bearings 26, A thrust rolling bearing such as 26 and a thrust bearing such as thrust needle bearings 27 for supporting a thrust load applied to the outer races 28 described below are provided. The thrust ball bearings 26 support rotation of the power rollers 8 while supporting the load applied to the power rollers 8 in the thrust direction. The thrust needle bearings 27, 27
Supports the thrust loads applied to the outer rings 28, 28 of the thrust ball bearings 27, 27 from the power rollers 8, 8, while supporting the pivot shafts 22, 22, and the outer ring 2
8 and 28 are allowed to swing around the support shafts 21 and 21.

A drive rod 29 is connected to one end (left end in FIG. 8) of each of the trunnions 6, and a drive piston 30 is provided on an outer peripheral surface of an intermediate portion of each drive rod 29. 30 are fixed. These drive pistons 30, 30 are respectively connected to drive cylinders 31,
31 is fitted in an oil-tight manner.

Further, a support wall 3 provided in a casing 32 is provided.
3 and a pair of rolling bearings 34 between the input shaft 15 and
34, the input shaft 15 is rotatably supported in the casing 32. In addition, each of the above rolling bearings 3
One of the inner rings 35, 35 constituting
The inner ring 35 that constitutes the rolling bearing 34 (to the right) is externally fitted to a holder 36 that is externally displaceably fitted to the outer peripheral surface of the input shaft 15 in the axial direction. A plate spring 38 is sandwiched between the rear surface of the holder 36 (the right side surface in FIG. 7) and a loading nut 37 fixed to the outer peripheral surface of the input shaft 15. The disc springs 38 keep the inner surfaces 2a, 4a of the disks 2, 4 even when the pressing device 9 is not operated.
a for elastically contacting the peripheral surfaces 8a, 8a of the power rollers 8, 8 with a preload. Furthermore,
The inner ring 3 constituting the other (left side in FIG. 7) rolling bearing 34
Reference numeral 5 is externally fitted and fixed to a support cylindrical portion 39 formed on the inner peripheral edge of the output gear 18.

In the case of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 15 is transmitted to the input side disk 2 via the pressing device 9. Then, the rotation of the input disk 2 is transmitted to the output disk 4 via the pair of power rollers 8, 8, and the rotation of the output disk 4 is extracted from the output gear 18. When changing the rotation speed ratio between the input shaft 15 and the output gear 18, the pair of drive pistons 30, 30 are displaced in opposite directions. The pair of trunnions 6 are displaced in opposite directions with the displacement of the driving pistons 30, 30. For example, the lower power roller 8 in FIG. Are displaced to the left in FIG. As a result, these power rollers 8, 8
The direction of the tangential force acting on the abutting portion between the peripheral surfaces 8a, 8a and the inner surfaces 2a, 4a of the input side disk 2 and the output side disk 4 changes. Then, with the change in the direction of this force, each of the trunnions 6, 6
In FIG. 7, they swing in opposite directions about the pivots 5, 5 pivotally supported by 20. As a result, as shown in FIGS. 5 and 6 described above, the contact position between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a, 4a changes, and the input shaft 15 The rotation speed ratio with the output gear 18 changes.

When the power rollers 8 are displaced in the axial direction of the input shaft 15 as a result of elastic deformation of the components during power transmission, the power rollers 8 are pivotally supported. Each of the displacement shafts 7, 7 is
It swings slightly around 1, 21. As a result of this swing, the outer races 28, 28 of the respective thrust ball bearings 26, 26 are formed.
Of the trunnions 6 and 6 are relatively displaced from each other. Since the thrust needle bearings 27 exist between the outer surface and the inner surface, the force required for the relative displacement is small. Therefore, the force for changing the inclination angle of each of the displacement shafts 7 can be small as described above.

In the case of the toroidal type continuously variable transmission configured and operated as described above, the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a,
In order to prevent slippage at each contact part with 4a,
It is necessary to secure the contact pressure of each of these contact portions. In the case of the conventional structure described above, the pressing device 9 and the plate spring 38
Thus, the contact pressure is ensured.

On the other hand, Japanese Patent Application Laid-Open No. 62-258254
JP-A-5-39848 and JP-A-5-39848 describe a structure in which a hydraulic second pressing device is provided in parallel with a loading cam type first pressing device. In the case of such a conventional structure, the second pressing device controls the pressing force (= thrust) according to the inclination angle of the power roller (in the case of Japanese Patent Application Laid-Open No. 62-258254), For example, when the brake is operated, the driving force input from the engine to the toroidal-type continuously variable transmission becomes negative, and the pressing force is generated in a state where the first pressing device does not generate the pressing force.

[0019]

In the case of a conventional toroidal-type continuously variable transmission configured and operated as described above, it is difficult to achieve both high transmission efficiency and high durability at the same time. First, in the case of a structure in which only a mechanical pressing device is provided, such as a loading cam type, when the driving force input to the toroidal type continuously variable transmission from the engine side becomes zero or negative, each power is controlled by the pressing device. Roller 8, peripheral surface 8
a, 8a and the inner surface 2 of each of the input and output disks 2, 4
a, it becomes impossible to secure the contact pressure with 4a. For this reason, when only a mechanical pressing device is provided, each of these peripheral surfaces 8
Sliding occurs at the contact portions between the inner surfaces 2a, 4a and the inner surfaces 2a, 4a, and there is a possibility that the surfaces 8a, 2a, 4a may be damaged, such as remarkable wear and seizure. If the cam surfaces 13 and 14 for constituting the pressing device 9 are formed in a symmetrical shape with respect to the circumferential direction, the contact pressure can be obtained even when the driving force becomes negative. Before and after the conversion from negative (or negative to positive), it is inevitable that the pressing force is lost or significantly reduced, and the possibility of occurrence of the slip cannot be eliminated.

In the case of the conventional structure shown in FIG. 7, even if the driving force input to the toroidal type continuously variable transmission becomes zero or negative due to the elasticity of the disc spring 38, the contact pressure is secured. In addition, the occurrence of the slip is prevented. However, for example, as in the case where the accelerator is suddenly returned during high-speed running and a large engine brake is generated, the power rollers 8
In order to secure a sufficient contact pressure even when the pressing force of the mechanical pressing device is completely lost while the disks 2 and 4 on the input side and the output side are rotating at high speed, The elasticity of the leaf spring 38 needs to be considerably increased. As a result, the contact pressure during traveling at a constant speed becomes excessive, and the rolling fatigue life of the peripheral surfaces 8a, 8a and the inner surfaces 2a, 4a may be reduced.

Such a situation is described, for example, in JP-A-1-169.
As described in Japanese Patent Application Publication No. 169, it is also possible that the toroidal type continuously variable transmission is used in two types of modes by connecting and disconnecting the clutch when the vehicle is running. That is, in the case of the structure described in Japanese Patent Application Laid-Open No. 1-169169, even when the power input from the engine to the toroidal type continuously variable transmission does not change significantly, the loading cam is connected with the connection and disconnection of the clutch. The direction of the rotational force input to the pressing device changes. For this reason, a region in which the pressing force generated by the pressing device becomes extremely small due to the connection and disconnection of the clutch is generated, which is considered to cause the above-mentioned damage such as remarkable wear and seizure. That is, in a mechanical pressing device such as a loading cam type, it is difficult to secure the contact pressure in response to a sudden torque fluctuation generated when the clutch is connected and disconnected, and the above-described damage is likely to occur. it is conceivable that.

On the other hand, Japanese Patent Application Laid-Open No. 62-258254
In the case of the structure described in Japanese Patent Application Laid-Open No. 5-39848, the pressing force is simply controlled in accordance with the inclination angle of the power roller, or the drive inputted to the toroidal type continuously variable transmission. Since the pressing force is generated by the hydraulic pressing device only when the force becomes negative, the contact pressure between the peripheral surface of each power roller and the inner surfaces of the input side and output side disks is not necessarily required. It cannot be controlled to the optimum value. As a result, the driving force input to the toroidal-type continuously variable transmission changes due to engine output fluctuation or the like, or due to a temperature change, the peripheral surface of the power roller and the inner surfaces of both the input and output disks. When the viscosity of the traction oil sent to the contact portion changes, it is not always possible to obtain an optimal pressing force, and there is a possibility that the transmission efficiency is reduced or durability cannot be ensured. The toroidal-type continuously variable transmission of the present invention has been invented in order to eliminate any of the above-mentioned disadvantages.

[0023]

A toroidal-type continuously variable transmission according to the present invention is similar to the above-mentioned conventional toroidal-type continuously variable transmission, and has a rotating shaft driven by a vehicle engine and a rotating shaft. First and second disks rotatably supported around the rotation axis with the inner surfaces facing each other around the rotation axis, and the outer surface of the first disk among the first disk and the rotation axis. And a pressing device for rotating the first disk together with the rotating shaft while pressing the first disk toward the second disk, and a pressing device that is twisted with respect to the central axes of the first and second disks. The vehicle includes a trunnion swinging about a pivot, and a power roller sandwiched between the first and second disks while being rotatably supported on the inner surface of the trunnion.

In particular, in the toroidal type continuously variable transmission according to the present invention, the pressing device increases the pressing force (= thrust) according to the magnitude of the torque of the power to be transmitted. And a second pressing device that generates a pressing force corresponding to the pressure of the pressure oil based on the pressure oil supplied from the pressure oil source.
A control valve for controlling the pressure of the pressure oil fed into the hydraulic cylinder is provided between a hydraulic cylinder constituting the second pressing device and a pressure oil source for supplying the pressure oil. I have. Further, the control valve includes a signal indicating the number of revolutions of the engine, a signal indicating the accelerator opening, a signal indicating the vehicle speed of the vehicle, the inner surfaces of the first and second disks, and the power roller. The pressure is adjusted based on one or a plurality of signals selected from signals indicating the temperature of the traction oil sent to the contact portion with the peripheral surface of the traction oil.

[0025]

The toroidal-type continuously variable transmission of the present invention configured as described above has a similar operation to that of the above-described conventional toroidal-type continuously variable transmission, and is provided between the first disk and the second disk. The transmission of the rotational force is performed by changing the rotation speed ratio between the two disks by changing the inclination angle of the trunnion. In particular, in the case of the toroidal-type continuously variable transmission of the present invention, the contact pressure of the contact portion between the inner surfaces of the first and second disks and the peripheral surface of the power roller is affected by changes in the operating conditions. And can always be maintained at the optimum value. For this reason, maintenance of transmission efficiency and securing of durability can be achieved at a high level.

[0026]

1 and 2 show a first embodiment of the present invention. The feature of the present invention is that the inner surfaces 2a and 4a of the input side and output side disks 2 and 4 and the peripheral surfaces of the power rollers 8 and 8 are used in order to maintain the transmission efficiency and the durability at a high level. Surfaces 8a, 8a (output side disk 4
(See FIGS. 5 to 7 for the power roller 8)
The contact pressure of the contact portion is always maintained at an optimum value irrespective of a change in the operating condition. Since the structure and operation of the other parts are the same as those of the above-described conventional structure, the illustration and description of the equivalent parts are omitted or simplified.
Hereinafter, the description will focus on the features of the present invention.

The pressing device 40 constituting the toroidal type continuously variable transmission according to the present invention includes a first pressing device 41 and a second pressing device 42, an input shaft 15a as a rotating shaft and a first disk. It is provided in parallel with the input side disk 2. The first pressing device 41 mechanically operates to increase the pressing force (= thrust) according to the magnitude of the torque of the power to be transmitted. The same loading cam type as the device 9 is used. In order to constitute such a first pressing device 41, the input side end of the input shaft 15a (the left end in FIG. 1).
The thrust rolling bearing 43
The input shaft 15a is rotatably supported relative to the input shaft 15a. Then, between a cam surface 13 formed on one side surface (the right side surface in FIG. 1) of the cam plate 10a and a cam surface 14 formed on the outer side surface (the left side surface in FIG. 1) of the input side disk 2 A plurality of rollers 12 held by a holder 11,
The loading cam type first pressing device 41 is configured by supporting the rotation of the rotation shaft 12 about the axis in the radial direction with respect to the center of the input shaft 15a.

The input side disk 2 is connected to the input shaft 15a.
The input shaft 15a is rotatably supported in synchronization with the input shaft 15a by a ball spline 44 at a portion near one end of the intermediate portion. Further, locking projections 45, 45 are formed on the other side surface (left side surface in FIG. 1) of the cam plate 10a, and these locking projections 45, 45 and the distal end of the drive shaft 46 are fixed. The driving arms 47, 47 provided are engaged with the distal ends thereof. The drive shaft 46 is rotatably driven by a vehicle engine (not shown). Therefore, when the driving engine is driven, the cam plate 10a is driven by the drive shaft 46.
Is driven to rotate, and based on the engagement between the rollers 12 and 12 and the cam surfaces 13 and 14, the input side disk 2
Is rotated toward the output side disk 4 while being pushed rightward in FIG.

On the other hand, the second pressing device 42 generates a pressing force (= thrust) according to the pressure of the pressure oil based on the pressure oil supplied from a pressure oil pump 48 as a pressure oil source.
For this reason, in the case of the illustrated example, a cylindrical wall 49 is formed on the outer peripheral surface of the cam plate 10a toward the input side disk 2. Of course, the inner peripheral surface of the cylindrical wall 49 is concentric with the outer peripheral surfaces of the input shaft 15a and the input side disk 2.
The inner diameter of the cylindrical wall 49 is slightly larger than the outer diameter of the input-side disk 2. The inner peripheral surface of the distal end portion of the cylindrical wall 49 and the outer peripheral surface of the input-side disk 2 are opposed to each other over the entire circumference. I have. An outer-diameter-side seal ring 50 is provided between the inner peripheral surface of the distal end portion of the cylindrical wall 49 and the outer peripheral surface of the input-side disk 2, and the outer-diameter side of the space 51 in which the rollers 12 are provided. It is oil-tightly closed. Also, the cam plate 1
0a and the outer peripheral surface of the input shaft 15a, and between the inner peripheral surface of the input disk 2 and the outer peripheral surface of the input shaft 15a, respectively.
52 is provided to close the inner diameter side of the space 51 in an oil-tight manner. The inner and outer seal rings 5 provided between the inner and outer peripheral surfaces of the input disk 2 and the inner peripheral surface of the distal end of the cylindrical wall 49 and the intermediate peripheral surface of the input shaft 15a.
Nos. 0 and 52 are held between the opposing peripheral surfaces over the entire operation range of the pressing device 40. Therefore, the space 51 is oil-tightly shut off from the outside except for the supply / discharge path 53 described below, and functions as a hydraulic cylinder constituting the second pressing device 42.

Further, the drive shaft 4 is provided in the space 51.
The pressure oil can be freely supplied and discharged through a supply and discharge passage 53 provided inside the input shaft 6 and the input shaft 15a. For this purpose, a concave hole 54 opening at one end face (the left end face in FIG. 1) of the input shaft 15a is formed inside one end of the input shaft 15a.
5a is formed concentrically. Then, the outer diameter side ends of the branch holes 55, 55 branching from the depth of the concave hole 54 toward the outside in the diameter direction of the input shaft 15 a, at the outer peripheral surface of the intermediate portion of the input shaft 15 a, in a pair. Inner diameter side seal ring 52,
An opening is provided in a portion between 52. A supply / discharge pipe 56 is provided at the center of the distal end face (the right end face in FIG. 1) of the drive shaft 46 so as to project concentrically with the input shaft 15a. 46 is connected to a base supply / discharge passage 57 provided inside. The outside diameter of the supply / discharge tube 56 is slightly smaller than the inside diameter of the opening side portion of the concave hole 54. A seal ring 58 is provided between the outer peripheral surface of the supply / discharge tube 56 and a portion near the inner peripheral surface opening of the concave hole 54, and the outer peripheral surface of the supply / discharge tube 56 and the inner peripheral surface of the concave hole 54 are provided. The space between them is sealed oil-tight.

The base supply / discharge path 57 communicates with the pressure oil pump 48 via a control valve 59. This control valve 59
Is used to control the pressure of the pressure oil fed into the space 51 functioning as the hydraulic cylinder. The pressure oil discharged to the base supply / discharge passage 57 based on a command signal from a controller 60 described below. To control the pressure. The controller 60 for issuing a command signal to the control valve 59 has a microcomputer built therein and sends out different command signals based on detection signals indicating various states sent from sensors (not shown) to control the pressure. . In the case of the present example, the detection signal is a signal representing the rotation speed of the vehicle driving engine, a signal representing the degree of accelerator opening, a signal representing the vehicle speed of the vehicle, and the input-side and output-side disks 2, 4 and the peripheral surface 8 of each of the power rollers 8, 8
a, 8a, and a signal representing the temperature of the traction oil fed into the contact portion with the traction oil.

In the case of the toroidal-type continuously variable transmission of the present invention configured as described above, the inner surfaces 2a and 4a of the input and output disks 2 and 4 and the power rollers 8 and
The contact pressure of the contact portion between the contact surface 8 and the peripheral surfaces 8a, 8a can always be maintained at an optimum value irrespective of a change in operating conditions. That is, the operation state of the control valve is switched according to the driving state of the automobile,
By adjusting the pressure of the pressurized oil fed into the space 51, the contact pressure is adjusted to cause a slip at the contact portion or an excessive surface pressure acts on the contact portion. Things can be prevented. For this reason, maintenance of transmission efficiency and securing of durability can be achieved at a high level. The above-described pressure control is performed in various types while considering combinations of the detection signals sent from the sensors to the controller 60. Such control is performed by storing the pressure to be applied in each case in the microcomputer while assuming many situations. Since the description in all of these cases is extremely redundant, here, the approximate relationship between each state value and the pressure will be described for each detection signal.

First, in the case of a signal representing the number of revolutions of the traveling engine, the torque (input torque) of the rotational force sent to the toroidal type continuously variable transmission through the drive shaft 46 is combined with a signal representing the accelerator opening degree. The magnitude of the torque is known, and the pressure is controlled to obtain a contact pressure corresponding to the magnitude of the input torque. That is, since the relationship between the rotation speed and the magnitude of the torque is known in advance as a characteristic curve of the engine, if this relationship is stored in the controller, the pressure is adjusted according to the magnitude of the input torque. it can. Since the torque changes depending on the accelerator opening even when the rotation speed is the same, a signal representing the accelerator opening is also considered.
FIG. 2 shows a state in which the pressing device 40 adjusts the force (thrust) for pressing the input-side disk 2 against the output-side disk 4 according to the magnitude of the input torque. In FIG. 2, the solid line α represents the relationship between the input torque and the thrust by the pressing device 40 constituting the toroidal-type continuously variable transmission of the present invention, and the broken line β represents the input when only the loading cam type pressing device is provided. The relationship between torque and thrust is represented by the dashed line γ
And a part of the broken line β located above the chain line γ is a loading cam type pressing device and a disc spring 3
8 shows the relationship between the input torque and the thrust when a preload spring such as 8 (see FIG. 7) is provided.

As is clear from the broken line β, when only the loading device of the loading cam type is provided, the thrust becomes extremely small (or completely lost) when the input torque is small (including zero). ), Causing damage as described above. On the other hand, when the preload spring is added, even if the input torque is small, the required thrust can be obtained to prevent the above-described damage, but if the input torque at that moment is small, the thrust increases. Can not. Therefore, when the input torque suddenly increases, such as during rapid acceleration, the thrust is insufficient (thrust increase cannot catch up with the torque increase), and the input side,
Sliding occurs at the contact portions between the inner side surfaces 2a, 4a of the output side disks 2, 4 and the peripheral surfaces 8a, 8a of the power rollers 8, 8, not only reducing the transmission efficiency, but also reducing The surfaces 2a, 4a, and 8a are easily damaged. On the other hand, in the case of the present invention, an optimum thrust can be obtained not only according to the input torque at that moment but also according to the input torque immediately after the fluctuation is expected (feedforward control becomes possible). That is, when the input torque is small and the thrust obtained by the first pressing device 41 is small, the pressure of the pressure oil fed into the space 51 is increased, and the pressure is required by the second pressing device 42. Get thrust. On the other hand, when the input torque becomes large and the thrust obtained by the first pressing device 41 becomes sufficiently large, the pressure of the pressure oil fed into the space 51 is reduced, and It prevents the disk 2 from being subjected to an excessive thrust. These controls can be performed not only according to the magnitude of the torque at that moment, but also according to expected fluctuations.

The thrust obtained by the second pressing device 42 is freely adjustable, so that the thrust obtained by the pressing device 40 is larger than the thrust obtained by the first pressing device 41. It can be set arbitrarily according to the driving situation. Therefore, if the characteristics of the first pressing device 41 are regulated so as not to generate an excessive thrust even when the input torque becomes maximum, the characteristics of the input-side and output-side disks 2 and 4 can be reduced. The contact pressure of the contact portions between the side surfaces 2a, 4a and the peripheral surfaces 8a, 8a of the power rollers 8, 8 can always be maintained at an optimum value irrespective of a change in operating conditions. or,
As is clear from the above description, in the case of the toroidal type continuously variable transmission of the present invention, the preload spring such as the disc spring 38 can be omitted. Therefore, the number of parts and the number of assembly steps can be reduced based on the omission of the preload spring. Further, when the input torque becomes large and a required thrust can be obtained only by the first pressing device 41, it is not necessary to send pressure oil into the space 51. Therefore, it is not necessary to feed the pressure oil from the pressure oil pump 48 into the space 51 when the vehicle is traveling at a constant speed. Therefore, the power loss caused by providing the hydraulic second pressing device 42 can be minimized.

Next, the signal representing the accelerator opening and the signal representing the vehicle speed of the vehicle predict the input torque itself and the fluctuation of the input torque, and are required at the next moment based on the fluctuation. Used to determine thrust.
For example, when the accelerator opening is suddenly reduced during high-speed traveling and a large engine brake is operated, the thrust generated by the first pressing device 41 rapidly decreases, and after passing through the zero point, The thrust generated by the first pressing device 41 increases. When the accelerator opening is suddenly increased, the thrust generated by the first pressing device sharply increases at the next moment. So, in these cases,
The pressure of the hydraulic oil fed into the space 51 is adjusted based on the signal indicating the accelerator opening and the signal indicating the vehicle speed of the vehicle to secure a required thrust or the thrust excessively increases. Prevent things.

Further, both the input side and output side disks 2,
The signal representing the temperature of the traction oil fed into the contact portion between the inner surfaces 2a, 4a of the power rollers 4 and the peripheral surfaces 8a, 8a of the power rollers 8, 8 is determined by the optimum thrust according to the viscosity of the traction oil. Use to get. That is, when the operation of the toroidal-type continuously variable transmission is continued, the temperature of the traction oil gradually increases due to stirring resistance or the like. or,
This temperature also changes depending on the outside air temperature such as a difference in season. Then, the viscosity of the traction oil gradually decreases as the temperature rises, and the thrust required to prevent slippage at each of the contact portions increases as the viscosity decreases.
Therefore, in the case of the toroidal type continuously variable transmission of the present invention,
The pressure of the pressure oil fed into the space 51 is adjusted based on the relationship between the temperature and the viscosity of the traction oil, which is known in advance, according to the change in the temperature. That is, the higher the temperature,
The thrust is increased by increasing the pressure.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of the first example described above, the cylindrical wall 49 for constituting the second pressing device 42 is provided integrally with the cam plate 10a, whereas in the case of the present example, the cylindrical wall 49a is provided.
Are formed separately from the cam plate 10a. That is, a cylindrical body 62 having an inward flange-shaped flange 61 at one end is fitted onto the cam plate 10a, and one side (the left surface in FIG. 3) of the cam plate 10a and the inner peripheral edge of the flange 61 are connected. , And are welded oil-tight over the entire circumference. In the case of such a present example, the manufacturing operation of the cam plate 10a having the cylindrical wall 49a is easier than in the case of the first example. Other configurations and operations are the same as those of the first example described above, and therefore, the description of the equivalent parts will be omitted.

Next, FIG. 4 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a pair of input-side disks 2, 2 are provided at both ends of an input shaft 15b, and the inner side surfaces 2a, 2a are opposed to each other so that large power can be transmitted. It is supported by splines 44,44. At the same time, a pair of output-side disks 4, 4 are attached to the intermediate portion of the input shaft 15 b, respectively.
a, 4a are the inner side surfaces 2a of the input side disks 2, 2, respectively.
In a state where the input shaft 15b faces the input shaft 15b, the input shaft 15b is rotatably supported. An output gear 18a is rotatably supported between the two output-side disks 4, 4 together with the two output-side disks 4, 4.

The so-called double-cavity toroidal type continuously variable transmission in which the input side disks 2 and 2 and the output side disks 4 and 4 are provided in parallel with each other in the power transmission direction as described above. However, the present invention is applicable. In this case, the pressing device 40 is provided on the back side (left side in FIG. 3) of one (left side in FIG. 3) input side disk 2. The lubricating oil passage 63 provided inside the input shaft 15b is for supplying lubricating oil to the possible parts such as the ball splines 44, 44 and the like. Pressing device 40 which is a feature of the present invention
Is the same as in the first example described above.

[0041]

Since the present invention is constructed and operates as described above, it is possible to improve the transmission efficiency and improve, for example, the running performance and fuel efficiency of a vehicle incorporating a toroidal type continuously variable transmission. Further, the fatigue life of the rolling bearing can be improved, and the durability can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a pressing force applied to an input side disk by a pressing device and an input torque.

FIG. 3 is a view similar to FIG. 1, showing a second example of the embodiment of the present invention;

FIG. 4 is a sectional view showing the third example with a part thereof omitted;

FIG. 5 is a side view showing a basic configuration of a conventionally known toroidal type continuously variable transmission in a state of maximum deceleration.

FIG. 6 is a side view showing a state at the time of maximum speed increase.

FIG. 7 is a sectional view showing an example of a conventional specific structure.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 input side disk (first disk) 2a inner surface 3 output shaft 4 output side disk (second disk) 4a inner surface 5 pivot 6 trunnion 7 displacement axis 8 power roller 8a peripheral surface 9 pressing device 10, DESCRIPTION OF SYMBOLS 10a Cam plate 11 Cage 12 Roller 13, 14 Cam surface 15, 15a, 15b Input shaft 16 Needle bearing 17 Flange 18, 18a Output gear 19 Key 20 Support plate 21 Support shaft 22 Pivot shaft 23 Round hole 24 25 Radial Needle Bearing 26 Thrust Ball Bearing 27 Thrust Needle Bearing 28 Outer Ring 29 Drive Rod 30 Drive Piston 31 Drive Cylinder 32 Casing 33 Support Wall 34 Rolling Bearing 35 Inner Ring 36 Holder 37 Loading Nut 38 Plate Spring 39 Support Cylindrical Part 40 Pressing Device 41 First pressing device 42 Second pressing Device 43 Thrust rolling bearing 44 Ball spline 45 Locking projection 46 Drive shaft 47 Drive arm 48 Pressure oil pump 49, 49a Cylindrical wall 50 Outer diameter side seal ring 51 Space 52 Inner diameter side seal ring 53 Supply / discharge path 54 Depression hole 55 Branch Hole 56 Supply / discharge pipe 57 Base supply / discharge path 58 Seal ring 59 Control valve 60 Controller 61 Flange 62 Cylindrical body 63 Lubricating oil flow path

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI F16H 59:72

Claims (1)

[Claims] A first rotating shaft rotatably driven by a driving engine of an automobile, and a first rotating shaft rotatably supported around the rotating shaft in a state in which inner surfaces of the rotating shaft are opposed to each other; A second disk, provided between the outer surface of the first disk and the rotation shaft,
A pressing device for rotating the first disk together with the rotation shaft while pressing the first disk toward the second disk; and a swinging device about a pivot axis which is twisted with respect to the center axis of the first and second disks. And a power roller sandwiched between the first and second disks while being rotatably supported on the inner surface of the trunnion. The pressing device increases the pressing force according to the magnitude of the torque of the power to be transmitted. The first pressing device is mechanically operated, and the pressure oil is supplied from a pressure oil source. A second pressing device that generates a pressing force according to the oil pressure of the oil is provided in parallel with each other, and a hydraulic cylinder that constitutes the second pressing device and a pressure oil source for supplying the pressure oil are provided. Between the hydraulic cylinders Writing and control valve is provided for controlling the pressure of hydraulic oil, the control valve receives a signal representing the rotational speed of the engine, a signal representing the accelerator opening,
The signal is selected from a signal representing the vehicle speed of the automobile and a signal representing the temperature of the traction oil sent to the contact portion between the inner surfaces of the first and second disks and the peripheral surface of the power roller. A toroidal-type continuously variable transmission, wherein the pressure is adjusted based on one or more signals.