JPH10299856A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize each displacement of trunnions set up at a first and a second cavity portion regardless of the difference in the quantity of elastic deformation, and secure the running stability of an automobile even in case of emergency. SOLUTION: A first and a second actuators 62 and 63 are supplied with, and emptied of pressure oil for displacing trunnions 6 and 6 set up at both a first and a second cavity portions 60 and 61 by a first and a second mutually independent control valves 68 and 69. And a clutch 64 is provided for a halfway of a transmission shaft 56 consisting of a power take-out means 74. When the difference in pressure for oil to be fed, becomes high between the first and second actuators 62 and 63, the aforesaid clutch 64 is thereby disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A toroidal type continuously variable transmission according to the present invention is used as an automatic transmission for a vehicle having a relatively large output.

[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 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 4 is attached to the end of the output shaft 3 concentrically
Is fixed. Inside the casing containing the toroidal-type continuously variable transmission, trunnions 6, 6 that swing about pivots 5, 5 that are twisted with respect to the input shaft 1 and the output shaft 3, 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 ends of the displacement shafts 7, 7 at the center thereof,
By swinging the trunnions 6, 6 about the pivots 5, 5, the inclination angles of the displacement shafts 7, 7 can be freely adjusted. Power rollers 8, 8 are provided around displacement shafts 7, 7 supported by the trunnions 6, 6, respectively.
Is rotatably supported. 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 side and output side disks 2 and 4 facing each other have cross sections each having a concave surface obtained by rotating an arc around the pivot 5. 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.

[0004] 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 this pressing device 9 so as to be elastic. 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. On one side surface (the right side surface in FIGS. 5 to 6) of the cam plate 10, a cam surface 13 which is an uneven surface extending in the circumferential direction is formed, and the outer surface of the input side disk 2 (the left 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, a plurality of rollers 12, 1, 1
2 is pressed against the cam surface 14 on the outer surface of the input disk 2. As a result, at the same time that the input side disk 2 is pressed by the plurality of power rollers 8, 8, based on the pressing of the pair of cam surfaces 13, 14 and the plurality of rollers 12, The input side disk 2 rotates.
Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 8, 8, and the output shaft 3 fixed to the output side disk 4 rotates.

In the case where the rotational speed ratio (speed ratio) between the input shaft 1 and the output shaft 3 is changed, first, when deceleration is performed between the input shaft 1 and the output shaft 3, the pivots 5, 5 are set as the center. The trunnions 6, 6 are swung so that the peripheral surfaces 8a, 8a of the power rollers 8, 8 are close to the center of the inner surface 2a of the input side disk 2 and the inner side of the output side disk 4 as shown in FIG. Each of the displacement shafts 7 is inclined so as to abut against the outer peripheral portion of the side surface 4a. Conversely, when increasing the speed, the trunnions 6 around the pivots 5
6 and the peripheral surface 8a of each of the power rollers 8 and 8,
8a is the inner surface 2a of the input side disk 2 as shown in FIG.
Each of the displacement shafts 7, 7 is brought into contact with a portion of the output disk 4 near the outer periphery and a portion of the inner surface 4 a of the output side disk 4 near the center.
Tilt. FIGS. 5 and 6 show the inclination angles of the respective displacement shafts 7 and 7.
, 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 cylindrical input shaft 15 via needle bearings 16 and 16, respectively. Further, the cam plate 10 is spline-engaged with the outer peripheral surface of the end portion (the left end portion in FIG. 7) of the input shaft 15, and is prevented from moving away from the input side disk 2 by the flange portion 17. Then, the input side disk 2 is moved by the cam plate 10 and the rollers 12, 12 based on the rotation of the input shaft 15.
A loading device 9 of a loading cam type that rotates while being pressed toward the output side disk 4 is configured. 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 synchronously.

Both ends of the pair of trunnions 6, 6 are supported by a pair of support plates 20, 20 so as to be swingable and displaceable in the axial direction (front and back directions in FIG. 7, and left and right directions in FIG. 8). I have.
The displacement shafts 7, 7 are supported by circular holes 23, 23 formed in the middle portions of the trunnions 6, 6, respectively. Each of the displacement shafts 7 is parallel and eccentric to the support shaft 2.
1 and 21 and pivot shaft portions 22 and 22, respectively.
Each of the support shaft portions 21 is fitted with the above-mentioned circular hole 23,2.
3, it is rotatably supported via radial needle bearings 24, 24. In addition, each of the pivot shaft portions 2
Power rollers 8, 8 are rotatably supported around 2, 22 via radial needle bearings 25, 25.

The pair of displacement shafts 7, 7 are provided at positions opposite to the input shaft 15 by 180 degrees. or,
The direction in which the respective pivot shaft portions 22, 22 of the respective displacement shafts 7, 7 are eccentric with respect to the respective support shaft portions 21, 21 is the same as the rotation direction of the input-side and output-side disks 2, 4. In FIG. 8, left and right directions are reversed. The eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 15 is provided. 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, the power rollers 8 tend to be displaced in the axial direction of the input shaft 15 (the left-right direction in FIG. 7 and the front-back direction in FIG. 8) due to the dimensional accuracy of the components. Even in this case, this displacement can be absorbed without applying excessive force to each component.

Further, between the outer surfaces of the power rollers 8 and 8 and the inner surfaces of the intermediate portions of the trunnions 6 and 6, the power rollers 8 are also arranged in this order from the outer surface of the power rollers 8. Thrust ball bearing 26 for supporting
26, and thrust needle bearings 27, 27 for supporting a thrust load applied to outer rings 28, 28 described below. 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. Further, the thrust needle bearings 27, 27
While supporting the thrust load applied from the power rollers 8, 8 to the outer rings 28, 28 constituting the thrust ball bearings 26, 26, these outer rings 28, 28 and the pivot shaft portions 22, 22 Swing about the support shaft portions 21 is allowed.

Further, drive rods 29, 29 are connected to one end (the left end in FIG. 8) of each of the trunnions 6, 6, and drive pistons 30, 30 are provided on the outer peripheral surface of the intermediate portion of each of the drive rods 29, 29. Is fixed. Each of these drive pistons 30 is connected to a drive cylinder 3 respectively.
1, 31 are oil-tightly fitted. The drive pistons 30, 30 and the drive cylinders 31, 31 constitute actuators for displacing the trunnions 6, 6 in the axial directions of the pivots 5, 5, respectively.

During operation 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. 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 rotational speed ratio between the input shaft 15 and the output gear 18, the pair of drive pistons 30,
30 are displaced by the same distance 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, the peripheral surfaces 8a, 8
The direction of the tangential force acting on the abutting portions of the input side disk 2 and the inner side surfaces 2a, 4a of the output side disk 4 changes. Then, with the change in the direction of the force, the trunnions 6 swing in opposite directions about the pivots 5 pivotally supported by the support plates 20.
As a result, as shown in FIGS. 5 and 6 described above, the peripheral surfaces 8a and 8a of the power rollers 8 and the inner surfaces 2a and 4a
a of the input shaft 15 and the output gear 1
8 changes.

Further, arcuate surfaces 32, 32 concentric with the pivots 5, 5 are formed on the outer peripheral surfaces of the end portions of the trunnions 6, 6, respectively. Then, a cable 33 as shown in FIG. 9 is bridged between the two arc surfaces 32, 32. In addition, stoppers 34, 34 are provided in portions of the cable 33 corresponding to the respective arc surfaces 32, 32, and the stoppers 34, 34 are attached to the respective arc surfaces 32, 32.
The cable 33 and each of the arcuate surfaces 32, 32 are prevented from slipping by engaging with a concave step formed in an intermediate portion of the cable. Such a cable 33 has a role of synchronizing the tilting of the two trunnions 6, 6 (the swinging motion about the pivots 5, 5) with each other. When the actuator (hydraulic drive) including the drive rods 29, 29, the drive pistons 30, 30, the drive cylinders 31, 31 and the like fails, the two trunnions 6,
6 are tilted in synchronization with each other. Therefore, even when the actuator fails, the inclination directions of the plurality of power rollers 8 sandwiched between the pair of the input side disk 2 and the output side disk 4 do not vary. As a result, no excessive frictional force acts between the inner side surfaces 2a, 4a of the discs 2, 4 and the peripheral surfaces 8a, 8a of the power rollers 8, 8, so that the toroidal type continuously variable transmission is prevented. Will not suffer any catastrophic damage and will also ensure minimum power transmission.

Each of the toroidal-type continuously variable transmissions shown in FIGS. 5 to 6 and FIGS. 7 to 8 has a structure in which the inner surface 2a of the input disk 2 and the inner surface 4a of the output disk 4 oppose each other. Are provided with two power rollers 8 in the cavity. Then, these two power rollers 8, 8 are
The disks 2 and 4 are arranged on the opposite side in the diameter direction with respect to the rotation center. On the other hand, by providing three power rollers in the cavity between the inner surface of the input-side disk and the inner surface of the output-side disk facing each other, large power can be freely transmitted between these two disks. A toroidal-type continuously variable transmission is also conventionally known, for example, as described in JP-A-3-74667.

FIG. 10 shows this conventional structure. The intermediate portions of the support pieces 36, 36, each of which is bent at 120 degrees, are pivotally supported at three positions at equal intervals in the circumferential direction of the fixed frame 35. Then, the adjacent support pieces 36, 3
The trunnions 6, 6 are respectively supported between the six so as to be able to swing and displace in the axial direction. One end of each of the trunnions 6, 6 is connected to one end of a drive rod 29, 29, and the other end of each of the drive rods 29, 29 is connected to a drive piston 30, 30 of a drive cylinder 31, 31 as an actuator. It is connected to. Each of these drive cylinders 31, 31 communicates via a control valve 37 with a discharge port of a pump 38 which is a hydraulic pressure source. This control valve 37
Has a sleeve 39 and a spool 40, each of which is displaceable in the axial direction (the left-right direction in FIG. 10).

When the inclination angle of the power rollers 8, 8 pivotally supported by the displacement shafts 7, 7 is changed to the respective trunnions 6, 6, the sleeve 39 is axially displaced by the control motor 41. . As a result, the pressure oil discharged from the pump 38 is sent to each of the drive cylinders 31 through a hydraulic pipe. The pressure oil causes the drive pistons 30, 30 fitted to the respective drive cylinders 31, 31 to be displaced in the same direction with respect to the rotation direction of the input side disk 2 and the output side disk 4 (see FIGS. 5 to 7). . The hydraulic oil pushed out from each of the drive cylinders 31, 31 with the displacement of the drive pistons 30, 30 is also passed through a hydraulic pipe (partly not shown) including the control valve 37, so that an oil sump 42 Is returned to.

On the other hand, the displacement of the drive piston 30 accompanying the feeding of the pressure oil is transmitted to the spool 40 via the cam 43 and the link 44, and displaces the spool 40 in the axial direction. As a result, with the drive piston 30 displaced by a predetermined amount, the flow path of the control valve 37 is closed, and the supply and discharge of pressure oil to and from the drive cylinders 31 and 31 are stopped. Accordingly, the amount of displacement of each of the trunnions 6, 6 in the axial direction, that is, the angle of inclination of each of the power rollers 8, 8, is only suitable for the amount of displacement of the sleeve 39 by the control motor 41. The basic structure for changing the inclination angle of each of the power rollers 8, 8 by a predetermined amount is shown in FIGS. 5 to 8 even when a structure in which three power rollers are provided in a cavity as shown in FIG. The same applies to such a structure in which two are provided.

When the toroidal type continuously variable transmission is used as a transmission for an automobile having an engine with a higher output, the input side disk 2 and the output side disk 4 are required to secure transmittable power. Are provided two by two, and these two input side disks 2 and two output side disks 4 are
It has been conventionally known to dispose them in parallel to each other in the power transmission direction, for example, as described in Japanese Patent Application Laid-Open No. 4-69439. FIG. 11 shows the structure described in this publication.

In this conventional structure, the housing 45
, The input shaft 15 is supported only rotatably.
The input shaft 15 has a front half 15a connected to a drive shaft for feeding power to a toroidal-type continuously variable transmission, and a rear half 15 that can rotate slightly with respect to the front half 15a.
b. Of these, a pair of input sides corresponding to the first and second disks described in the claims are provided near both ends in the axial direction (left-right direction in FIG. 11) of the rear half portion 15b corresponding to the rotating shaft described in the claims. Each of the disks 2, 2 has a respective inner surface 2, each corresponding to a first concave surface as claimed in the claims.
a, 2a are supported via ball splines 46, 46 in a state where they face each other.

A back surface (a surface opposite to the inner surface 2a in the axial direction) of one of the input disks 2 (the right side in FIG. 11),
A seat plate 47 and disc springs 48, 48 are provided in series with each other between a loading nut 87 fixed to the end of the front half 15a. Further, the rear surface of the other input side disk 2 (left side in FIG. 11) and the cam plate 1 constituting the pressing device 9
0 on one side (the right side in FIG. 11)
The thrust needle bearing 49 and the disc springs 48, 48 are provided in series with each other. This thrust needle bearing 49
Compensates for the relative rotation between the cam plate 10 and the other input side disk 2. The disc springs 48 apply a preload to the input disks 2 and 2 toward the output disks 4 and 4 described below.

A pair of output-side disks 4, 4 corresponding to the third and fourth disks described in the claims are respectively provided around the intermediate portion of the rear half 15b on the second concave surface described in the claims. In a state where the corresponding inner surfaces 4a, 4a and the inner surfaces 2a, 2a of the input side disks 4, 4 are opposed to each other, the input disks 15 are rotatably supported with respect to the input shaft 15. A plurality of power rollers 8, 8 rotatably supported by a plurality of trunnions 6, 6 via a displacement shaft 7 (see FIGS. 5 to 8 described above) are connected to the input and output disks 2, 4, respectively. Between the two inner side surfaces 2a, 4a.
Each of the power rollers 8, 8 is adapted to match the gear ratio between each of the input-side disks 2, 2 and the output-side disks 4, 4,
Tilt synchronously.

An output shaft 50 is provided inside the housing 45 at a portion opposite to the front half 15a, and the input shaft 1
5 and rotatably supported independently of the latter half 15b. Then, a rotation transmitting means is provided between the output shaft 50 and the pair of output-side disks 4, 4, so that the rotation of both output-side disks 4, 4 can be transmitted to the output shaft 50.

In order to constitute the rotation transmitting means, a tubular sleeve is provided inside a through hole 52 provided in a partition wall 51 existing between the pair of output side disks 4, 4 inside the housing 45. 53, a pair of rolling bearings 54, 5
4 support. The pair of output side disks 4,
4 are spline-engaged with both ends of the sleeve 53. An output gear 18a is fixedly provided at an intermediate portion of the sleeve 53 and inside the partition wall 51. Furthermore,
A part of each of the output side disks 4 and 4 is used for the sleeve 53.
Roller bearings 55 are provided between the inner peripheral surface of the portion protruding from the outer peripheral surface and the outer peripheral surface of the input shaft 15.
These roller bearings 55 allow the relative rotation between the output disks 4 and the input shaft 15 and the relative displacement in the axial direction.

On the other hand, inside the housing 45, a transmission shaft 56 is rotatably supported in parallel with the input shaft 15 and the output shaft 50. The first transmission gear 57 fixed to one end (left end in FIG. 11) of the transmission shaft 56 and the output gear 18a are directly meshed with each other, and the first transmission gear 57 fixed to the other end (right end in FIG. 11) of the transmission shaft 56. A second transmission gear 58 and a third transmission gear 59 fixed to the end of the output shaft 50;
The gears are meshed via an idle gear (not shown). With such a rotation transmitting means, the output shaft 50 rotates in the opposite direction to the output disks 4, 4 with the rotation of the pair of output disks 4, 4. The first half 1
A loading cam type pressing device 9 is provided between 5a and the other (the left side in FIG. 11) input side disk 2, similarly to the toroidal type continuously variable transmission shown in FIGS. I have. In addition, a thrust ball bearing 88 is provided between the cam plate 10 constituting the pressing device 9 and the flange portion 17 formed on the outer peripheral surface of the front end of the rear half portion 15b. While supporting the thrust load acting on the cam plate 10, the cam plate 10 and the rear half 15b can be freely displaced relative to each other in the rotational direction.

During operation of the toroidal type continuously variable transmission shown in FIG. 11 configured as described above, the pair of input side disks 2 and 2 rotate simultaneously with the rotation of the input shaft 15,
This rotation is transmitted to the pair of output side disks 4 and 4 at the same time and at the same speed ratio, and is transmitted to the output shaft 50 by the above-mentioned rotation transmitting means and taken out. At this time, since the transmission of the rotational force is performed in two parallel systems, large power (torque) can be transmitted freely.
During operation, the interval between the pair of input side disks 2 and 2 tends to be reduced by the operation of the pressing device 9. As a result, the inner surfaces 2a and 2a of the input disks 2 and 2 and the inner surfaces 4a and 4a of the output disks 4 and 4 and the peripheral surfaces 8a and
8a is strongly contacted, and power transmission is performed efficiently.

As shown in FIG. 11, in the case of a so-called double-cavity toroidal-type continuously variable transmission in which the transmission of rotational force is performed in two parallel systems, the inside of each cavity, that is, one input side. In the first cavity 60 between the disk 2 and the output disk 4 opposed to the input disk 2, and between the other input disk 2 and the output disk 4 opposed to the input disk 2. It is necessary to make the inclination angles of the trunnions 6 and 6 installed in the second cavity 61 coincide with each other. If the inclination angle of the trunnion 6 installed in the first cavity 60 and the inclination angle of the trunnion 6 installed in the second cavity 61 are different, in the first and second cavities 60 and 61, Slip occurs at the contact portions between the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a, 4a of the input and output disks 2, 4, respectively. Such slippage not only deteriorates the transmission efficiency of the toroidal-type continuously variable transmission, but also causes troubles such as abnormal wear and seizure in a severe case.

On the other hand, in the case of a conventionally known double cavity type toroidal type continuously variable transmission,
The hydraulic pressure that feeds the drive cylinders 31, 31 (FIG. 8) for driving the trunnions 6, 6 installed in both cavities 60, 61 in the axial direction of the pivots 5, 5 is supplied to a single control valve 37. (FIG. 10). Therefore, the hydraulic pressures sent to both drive cylinders 31, 31 are equal to each other.

[0029]

If the forces required to axially displace the trunnions 6, 6 installed in the first and second cavities 60, 61 by a predetermined amount in the axial direction are equal to each other, the two cavities are equal to each other. Even if the hydraulic pressures fed into the drive cylinders 31, 31 relating to 60, 61 are equal to each other, no particular problem occurs. However, when a double-cavity toroidal type continuously variable transmission is actually configured, the difference in the amount of elastic deformation due to the difference in the configuration of the respective cavities 60 and 61 or the dimensional error unavoidable in processing, etc. Thus, even if the same force is applied to the trunnions 6, 6 installed in the cavities 60, 61, the displacement of the trunnions 6, 6 in the axial direction of the pivots 5, 5 (FIGS. 5, 6, 8) is reduced. May differ from each other.

For this reason, in the case of a conventional toroidal type continuously variable transmission of the double cavity type, the peripheral surfaces 8a, 8a of the power rollers 8, 8 and the inner surfaces 2a of the input side, output side disks 2, 4, There is no denying that the transmission efficiency of the toroidal-type continuously variable transmission is deteriorated or a failure such as abnormal wear or seizure occurs due to the slip at the contact portion with the 4a. The toroidal type continuously variable transmission of the present invention is invented in order to prevent the difference in the displacement amount of the trunnions 6 in each of the cavities 60 and 61 from occurring, which causes such a reduction in efficiency and a failure. It is.

[0031]

A toroidal type continuously variable transmission according to the present invention comprises a rotating shaft, a first disk and a second disk, similarly to the above-mentioned conventional double cavity type toroidal type continuously variable transmission. , A third disk and a fourth disk, a first trunnion, a second trunnion, a plurality of power rollers, a first actuator, a second actuator, and power take-out means. Among these, the first disk and the second disk each have one axial surface formed as a first concave surface having an arc-shaped cross section, and with the first concave surfaces facing each other, both axial ends of the rotating shaft. In addition, it is supported rotatably with this rotating shaft. Further, the third disk and the fourth disk each have one axial surface formed as a second concave surface having an arc-shaped cross section, and the rotating shaft is rotated in a state where each of the second concave surface and the first concave surface are opposed to each other. Is supported around the intermediate portion of the shaft so as to freely rotate about the rotating shaft and displace in the axial direction. The first trunnion is disposed between the first disk and the third disk with respect to the axial direction, and is displaced in the axial direction of a pivot that is in a torsion position with respect to the rotation axis, and is centered on the pivot. And swings around the pivotal axis with the displacement of the pivotal axis in the axial direction. The second trunnion is disposed between the second disk and the fourth disk with respect to the axial direction, and is displaced in the axial direction of a pivot located at a position twisted with respect to the rotation axis, and the second trunnion is centered on the pivot. And swings around the pivotal axis with the displacement of the pivotal axis in the axial direction. In addition, the plurality of power rollers have a circumferential surface as a convex surface of a rotating arc surface, and are rotatably supported by displacement shafts supported by the first and second trunnions, and the first and third discs are rotated. Is sandwiched between the first and second concave surfaces provided on the second and fourth discs or between the first and second concave surfaces provided on the second and fourth discs. Further, the first actuator displaces the first trunnion in the axial direction of the pivot based on supply and discharge of pressure oil, and the second actuator displaces the second trunnion based on supply and discharge of pressure oil. Displace in the axial direction of the pivot. Further, the power take-out means is for taking out the rotation of the third and fourth discs.

In particular, in the toroidal type continuously variable transmission according to the present invention, a first supply / discharge flow path for supplying / discharging pressure oil to / from the first actuator, and a pressure oil supply / discharge to the second actuator. Therefore, a second supply / discharge flow path provided independently of the first supply / discharge flow path, a clutch connected in series in the middle of the power take-out means, and a clutch release for disconnecting the clutch Means. A first control valve for controlling the supply and discharge of pressure oil to and from the first actuator is provided in the middle of the first supply / drain passage, and the second actuator is provided in the middle of the second supply / discharge passage. A second control valve for controlling the supply and discharge of the pressure oil to and from each of them is provided. The clutch releasing means disconnects the clutch when the difference between the hydraulic pressure for driving the first actuator and the hydraulic pressure for driving the second actuator becomes equal to or greater than a predetermined value.

[0033]

In the case of the toroidal type continuously variable transmission of the present invention configured as described above, the hydraulic pressure fed into the first actuator and the hydraulic pressure fed into the second actuator can be controlled independently. Therefore, the amount of displacement of the trunnion installed in each cavity can be made substantially the same irrespective of the ease of elastic deformation of each cavity portion. Therefore, regardless of the ease of elastic deformation of each cavity portion, the amount of displacement of the trunnion installed in each cavity portion is made equal, the inclination angle of the power roller installed in each cavity is made almost equal, and the transmission efficiency deteriorates. Alternatively, it is possible to prevent occurrence of troubles such as abnormal wear and image sticking.

If the difference between the hydraulic pressures fed into the first and second actuators exceeds a range that can be caused by the ease of elastic deformation of each of the cavities, the clutch release means is activated by the clutch release means. Disconnect. That is,
As described above, when the difference between the hydraulic pressures fed into the two actuators is large, the displacement amounts of the trunnions installed in the respective cavities are different from each other. It is considered that significant sliding friction occurs in the contact portion. If such a state continues, seizure occurs in the toroidal type continuously variable transmission, and there is a possibility that the toroidal type continuously variable transmission locks (stops rotating). If the toroidal continuously variable transmission connected to the drive wheels of the vehicle locks, if no countermeasures are taken, the drive wheels will lock, etc. This may be the case. In contrast, in the case of the toroidal-type continuously variable transmission of the present invention, by disconnecting the clutch, the connection between the drive wheel and the toroidal-type continuously variable transmission is disconnected, and the drive wheel is locked. This prevents the car from being safely stopped by normal braking.

[0035]

1 to 3 show a first embodiment of the present invention. A feature of the present invention is a toroidal type continuously variable transmission of a double cavity type. In order to change the speed ratio between the first and second cavities 60 and 61, trunnions provided in these two cavities 60 and 61 are provided. 6,
A hydraulic control circuit for controlling the hydraulic pressure fed into the first and second actuators 62 and 63 for displacing the shaft 6 in the axial direction, and a clutch 64 disconnected for the operation of the hydraulic control circuit And there. The specific structure and operation of each component of the main body of the toroidal-type continuously variable transmission are the same as those of the conventional structure shown in FIGS. 7 to 11, so that illustration and description of equivalent parts are omitted or simplified. Hereinafter, a description will be given mainly of the characteristic portions of the present invention. Each of the first and second actuators 62 and 63 has a so-called double-acting type in which the driving piston 30 is oil-tightly fitted inside the driving cylinder 31 as shown in FIG. Hydraulic cylinder.

A first supply / drain passage 66 for supplying / discharging pressure oil to / from the first actuator 62 is provided between a discharge port of a pressure oil pump 65 serving as a pressure oil source and the first actuator 62. ing. A second supply / drain passage 67 for supplying / discharging pressure oil to / from the second actuator 63 is provided between the discharge port of the pressure oil pump 65 and the second actuator 63. The second supply / discharge passage 67 and the first supply / discharge passage 66
Are provided independently of each other. Among these first and second supply / discharge passages 66, 67, a first control valve for controlling supply / discharge of pressure oil to / from the first actuator 62 is provided in the middle of the first supply / discharge passage 66. 68 are provided in series. In the middle of the second supply / drain passage 67, a second control valve 69 for controlling the supply / discharge of pressure oil to / from the second actuator 63 is provided.
They are provided in series.

The first and second control valves 68 and 69 are
Similarly to the control valve 37 incorporated in the conventional structure shown in FIG. 10, the control valve 41 comprises a sleeve 39 and a spool 40. 62, 6
The hydraulic pressure fed into the first and second actuators 62 and 63 is controlled by axially displacing the spool 40 (or the sleeve 39) by the driving rod 29 constituting the third. That is, the first and second control valves 68 and 69 are connected to the sleeve 3 by the control motor 41a.
9 (or the spool 40) in an amount corresponding to (proportional to) the axial displacement of the first and second cavities 60,
In order to displace the trunnions 6, 6 in 61, the hydraulic pressure fed into the first and second actuators 62, 63 is controlled.

In the case of this embodiment, the first and second control valves 6
8 and 69 are synchronously controllable by one control motor 41a corresponding to the single drive mechanism described in claim 2. That is, the output shaft 7 of the control motor 41a
A pair of driven gears 72 and 72
Is engaged. These driven gears 72, 72 are connected to the input shaft 7 of the first and second control valves 68, 69, respectively.
3, 73 fixed. And these two control valves 6
The sleeve 39 and the sleeve 39 have an amount (axial length) corresponding to the rotation amount (rotation angle) of the input shafts 73 and 73, respectively.
(Or the spool 40) is displaced, and the amount by which the trunnions 6, 6 are to be displaced in the axial direction of the pivots 5, 5 (see FIGS. 5, 6, 8) is set.

A clutch 64 is connected in series with the transmission shaft 56 in the middle of the transmission shaft 56 constituting the power take-out means 74. In the case of the present example, the power take-out means 74 is fixed to the transmission shaft 56 and a sleeve 53 provided between the pair of output-side disks 4, 4 and an outer peripheral surface of an intermediate portion of the sleeve 53. It comprises an output gear 18a and a first transmission gear 57 fixed to the end of the transmission shaft 56. Although omitted in FIG. 1, a second transmission gear 58 (see FIG. 11) is provided downstream of the clutch 64.
And the like, the rear side of the power take-out means 74 is connected.
The clutch 64 is normally used as the clutch 64
It is connected based on the hydraulic pressure in the hydraulic chamber provided inside,
The power is transmitted from the front side to the rear side of the power take-out means 74. On the other hand, the clutch releasing means 7 described below
At the time of the operation of 5, by opening the hydraulic chamber to the atmosphere,
Disconnect the connection between the preceding stage and the subsequent stage.

The clutch releasing means 75 includes a differential valve 76
Is provided. The differential valve 76 is formed by fitting a differential valve body 78 in a cylinder 77 in an oil-tight manner so as to be freely displaceable in the axial direction. The differential valve element 78 includes a pair of return springs 7.
9, 79, it is elastically pressed toward the axial center position of the cylinder 77. Therefore, the differential valve element 78
Exists in the neutral position shown in FIG. 2 unless an external force acts. The hydraulic pressure in the first actuator 62 is introduced to one end (the left end in FIGS. 2 and 3) of the cylinder 77 via a first hydraulic pressure introduction passage 80. On the other hand, the hydraulic pressure in the second actuator 63 is introduced to the other end (the right end in FIGS. 2 and 3) of the cylinder 77 via a second hydraulic pressure introduction passage 81. The hydraulic pressure introduced from both the first and second actuators 62 and 63 to both ends of the cylinder 77 is, of these two actuators 62 and 63,
The parts which correspond to one another, i.e. the parts which should theoretically have the same hydraulic pressure, are introduced.

A communication passage 82 is provided at the axial center of the differential valve element 78 so as to allow the inner surfaces of the cylinder 77 on the opposite side in the diameter direction to communicate with each other. Then, one side in the diameter direction of the inner peripheral surface of the intermediate portion of the cylinder 77 (see FIGS.
A pair of communication ports 83a and 83b, each of which communicates with the hydraulic chamber of the clutch 64, are provided in the upper part) so as to be separated from each other in the axial direction of the cylinder 77 and sandwich the communication passage 82 therebetween. An oil reservoir 8 is provided on the other side (lower side in FIGS. 2 and 3) in the diameter direction of the inner peripheral surface of the intermediate portion of the cylinder 77.
Drain port 85 opened to the atmosphere by connecting to 4
Is provided so as to always communicate with the communication passage 82 regardless of the displacement of the differential valve body 78. As shown in FIG. 2, the state in which the differential valve element 78 is at the neutral position of the cylinder 77, that is, the first and second actuators 62, 6
In a state where the hydraulic pressures in the cylinders 3 are substantially equal, the pair of communication ports 83a and 83b are closed by the lands of the differential valve body 78, and the clutch 64 is kept in a state in which the pressure oil is sealed. Keep connected. In this case, if necessary, an oil supply path for feeding pressure oil into the hydraulic chamber of the clutch 64 is provided to hold the clutch 64 in the connected state.

On the other hand, when the difference between the oil pressures in the first and second actuators 62 and 63 is large, as shown in FIG. The communication valve 82 is displaced in the axial direction, and is provided at a central portion in the axial direction of the differential valve element 78.
(Or 83b) and the drain port 85. As a result, the pressure in the hydraulic chamber of the clutch 64 decreases,
The connection of the clutch 64 is disconnected. In this case, the supply of the pressure oil to the hydraulic chamber of the clutch 64 through the oil supply path is stopped, or the amount of the pressure oil fed into the hydraulic chamber through the oil supply path is controlled through the communication passage 82. Make it sufficiently less than the amount of pressure oil discharged from the hydraulic chamber.

In the case of the toroidal-type continuously variable transmission of the present invention configured as described above, the hydraulic pressure fed into the first actuator 62 and the hydraulic pressure fed into the second actuator 63 can be controlled independently. For this reason, the trunnions 6, 6 installed in the first and second cavities 60, 61, respectively.
Can be made substantially the same regardless of the ease with which the cavities 60 and 61 are elastically deformed. That is, the sleeve 39 (see FIG. 10) of the first and second control valves 68, 69 is displaced in the axial direction by the same length based on the energization of the control motor 41a. In a state where the trunnions 6, 6 in the cavities 60, 61 are displaced by an amount corresponding to the displacement of the sleeve 39 in the axial direction, the first and second control valves 68, 69 are turned on by the first and second control valves 68, 69. Then, the supply and discharge of the pressure oil into and from the second actuators 62 and 63 are stopped.
Therefore, regardless of the easiness of elastic deformation of the cavities 60 and 61, the displacement amounts of the trunnions 6 and 6 installed in the cavities 60 and 61 are made equal, and the powers installed in the cavities 60 and 61 are made equal. By making the inclination angles of the rollers 8 approximately equal, it is possible to prevent the transmission efficiency from deteriorating, or to prevent the occurrence of troubles such as abnormal wear and seizure. In the conventional double-cavity toroidal-type continuously variable transmission, in order to make the inclination angles of the power rollers 8 and 8 installed in the first and second cavities 60 and 61 equal to each other, the two cavities 60 and 61 are connected to each other. A cable was hanging between them.
In the case of the present invention, as described above, each cavity 60, 61
Since the inclination angles of the power rollers 8 and 8 installed in the power cables can be made substantially equal, the cable can be eliminated.

The first and second actuators 6
The difference in the hydraulic pressure fed into each of the cavities 6 and 63
If it becomes larger than the range that can be caused by the elastic deformation of the portions 0 and 61, the clutch releasing means 75
Disconnects the clutch 64. That is, when the difference between the hydraulic pressures fed into the two actuators 62 and 63 becomes abnormally large, the switching state of the differential valve 76 becomes as shown in FIG. 3, and the hydraulic pressure in the hydraulic chamber of the clutch 64 is released.
The connection of the clutch 64 is disconnected.

As described above, the state where the difference between the hydraulic pressures fed into the two actuators 62 and 63 is abnormally large is caused by the trunnion 6 installed in each of the cavities 60 and 61,
6 are different from each other, and in one or both cavities 60 and 61, the peripheral surface 8a (see FIGS. 5 to 8 and 11) of the power rollers 8 and the input side which is the first and second concave surfaces,
It is considered that remarkable sliding friction occurs in the contact portions between the output side disks 2 and 4 and the inner surfaces 2a and 4a. If such a state continues, seizure occurs in the toroidal type continuously variable transmission, and there is a possibility that the toroidal type continuously variable transmission locks (stops rotating). If the toroidal continuously variable transmission connected to the drive wheels of the vehicle locks, if no countermeasures are taken, the drive wheels will lock, etc. This may be the case. In contrast, in the case of the toroidal type continuously variable transmission of the present invention, the clutch 64
By disconnecting the connection, the connection between the drive wheel and the toroidal-type continuously variable transmission is disconnected, and the drive wheel is prevented from being locked, and the vehicle can be safely stopped by a normal brake operation. .

Next, FIG. 4 shows a second example of the embodiment of the present invention. In the case of this example, the first,
The second control valves 68, 69 can be controlled independently of each other by independent control motors 41b, 41c. Therefore, in the case of this example, the difference in the amount of elastic deformation between the first and second cavities 60, 61 is large, and the speed ratio obtained when the displacement of the trunnions 6, 6 is the same is different. In such a case, the first and second control valves 6
8, 69 can be appropriately controlled according to the difference between the deformation amounts.
Other configurations and operations are the same as those in the first example described above, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted. In the case of the structure of the first example described above,
As long as the difference in the amount of elastic deformation between the first and second cavities 60 and 61 is small and the amount of displacement of the trunnions 6 and 6 is made equal, the gear ratios obtained in the two cavities 60 and 61 are equal to each other. If one control motor 41
There is an advantage that the entire device can be configured to be small in a.

Incidentally, JP-A-1-169169, 1
As described in JP-A-320266, a toroidal-type continuously variable transmission is combined with a planetary gear reduction mechanism to transmit the driving force only at the time of low-speed traveling by the toroidal-type continuously variable transmission. Is transmitted by a planetary gear mechanism to reduce the torque applied to the toroidal-type continuously variable transmission during high-speed traveling, thereby improving the durability of each component. When the present invention is implemented in such a structure, a clutch is provided in each transmission unit constituting the structure, and disconnection of all clutches when an abnormality occurs, or with a toroidal type continuously variable transmission. 1 between the drive wheel and the entire transmission combined with the planetary gear reduction mechanism
The clutch is disconnected when an abnormality occurs, or a plurality of clutches are provided between the toroidal type continuously variable transmission and the planetary gear reduction mechanism, and all the clutches are activated when an abnormality occurs. Disconnect. In any case, the lock of the toroidal type continuously variable transmission is not linked to the lock of the drive wheels. Further, each of the above-described examples is based on the difference between the hydraulic pressures in the first and second actuators 62 and 63 and the differential valve 76.
It is configured to control the open / close state of the device. On the other hand, the hydraulic pressure in the first and second actuators 62 and 63 is detected by the first and second pressure sensors independent of each other, and the detection signals of these two pressure sensors are electrically compared with each other. It is also possible to control the open / close state of a solenoid valve for controlling the connection / disconnection of the clutch.

[0048]

Since the present invention is constructed and operates as described above, the efficiency and reliability of the toroidal-type continuously variable transmission are improved, and the toroidal-type continuously variable transmission as an automatic transmission for an automobile is improved. It can contribute to practical use.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first example of an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a differential valve constituting a clutch releasing means in a normal state.

FIG. 3 is a schematic cross-sectional view showing a state when an abnormality occurs.

FIG. 4 is a schematic view showing a second example of the embodiment of the present invention.

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 a first example of a specific structure of a conventionally known toroidal type continuously variable transmission.

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

FIG. 9 is a diagram showing an example of a conventionally known cable viewed from a side in FIG. 8;

FIG. 10 is a partial cross-sectional view showing a second example of a specific structure of a conventionally known toroidal-type continuously variable transmission.

FIG. 11 is a partial sectional view showing the third example.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 input side disk 2a inner surface 3 output shaft 4 output side disk 4a inner surface 5 pivot 6 trunnion 7 displacement shaft 8 power roller 8a peripheral surface 9 pressing device 10 cam plate 11 retainer 12 roller 13, 14 cam surface 15 Input shaft 15a Front half 15b Rear half 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 Arc surface 33 Cable 34 Stopper 35 Frame 36 Support piece 37 Control valve 38 Pump 39 Sleeve 40 Spool 41, 41a, 41b, 41c Control motor 42 Oil reservoir 43 Cam 44 Link 45 Housing Reference Signs List 6 ball spline 47 seat plate 48 disc spring 49 thrust needle bearing 50 output shaft 51 partition wall 52 through hole 53 sleeve 54 rolling bearing 55 roller bearing 56 transmission shaft 57 first transmission gear 58 second transmission gear 59 third transmission gear Reference Signs List 60 First cavity 61 Second cavity 62 First actuator 63 Second actuator 64 Clutch 65 Pressure oil pump 66 First supply / discharge flow path 67 Second supply / discharge flow path 68 First control valve 69 Second control valve 70 Output Shaft 71 Drive gear 72 Follower gear 73 Input shaft 74 Power take-out means 75 Clutch release means 76 Differential valve 77 Cylinder 78 Differential valve body 79 Return spring 80 First hydraulic pressure introduction path 81 Second hydraulic pressure introduction path 82 Communication paths 83a, 83b Communication port 84 Oil reservoir 85 Drain port 87 Loading nut 88 Last ball bearings

Claims (4)

[Claims] 1. A rotating shaft and a first concave surface having an arc-shaped cross section on one side in each of the axial directions, and in a state where the first concave surfaces are opposed to each other, at both axial ends of the rotating shaft, The first disk and the second disk supported in a rotatable state together with the rotating shaft, and one axial surface of each of the first and second disks is a second concave surface having an arc-shaped cross section, and each of the second concave surface and the first concave surface. A third disk and a fourth disk, which are supported around the intermediate portion of the rotation shaft in a state where they are opposed to each other so as to freely rotate about the rotation shaft and displace in the axial direction.
It is disposed between the first disk and the third disk with respect to the axial direction, and is capable of freely displacing in the axial direction of a pivot located at a position twisted with respect to the rotation axis and swinging about the pivot. A first trunnion that swings about the pivot axis with a displacement of the pivot axis in the axial direction, and a first trunnion that is arranged between the second disc and the fourth disc in the axial direction;
An axial displacement of the pivot that is in a torsional position with respect to the rotation axis and a swing about the pivot are free, and the pivot about the pivot is accompanied by the displacement of the pivot in the axial direction. The two trunnions, the peripheral surface of which is a circular arc-shaped convex surface, is rotatably supported by a displacement shaft supported by the first and second trunnions, and is provided on the first and third disks. A plurality of power rollers sandwiched between the second concave surfaces or between the first and second concave surfaces provided on the second and fourth disks, and A first actuator that displaces one trunnion in the axial direction of the pivot, a second actuator that displaces the second trunnion in the axial direction of the pivot based on supply and discharge of pressure oil, and the third and fourth disks Power take-out means to take out the rotation of In the toroidal-type continuously variable transmission, a first supply / discharge flow path for supplying / discharging pressure oil to / from the first actuator, and a first supply / discharge path for supplying / discharging pressure oil to / from the second actuator. A second supply / discharge flow path provided independently of the flow path, and a first control valve provided in the middle of the first supply / discharge flow path for controlling supply / discharge of pressure oil to / from the first actuator. And, in order to control the supply and discharge of pressure oil to the second actuator, a second control valve provided in the middle of the second supply and discharge flow path, a clutch connected in series in the middle of the power take-out means, A clutch releasing means for disconnecting the clutch, wherein the clutch releasing means is provided when a difference between a hydraulic pressure for driving the first actuator and a hydraulic pressure for driving the second actuator is equal to or more than a predetermined value. Disconnect the clutch. Idar-type continuously variable transmission. 2. The toroidal-type continuously variable transmission according to claim 1, wherein the drive of the first and second control valves is performed synchronously by a single drive mechanism. 3. A detection signal of a first pressure sensor for detecting a hydraulic pressure in the first actuator when a difference between a hydraulic pressure for driving the first actuator and a hydraulic pressure for driving the second actuator becomes equal to or greater than a predetermined value. Or by comparing the detection signal of the second pressure sensor that detects the oil pressure in the second actuator, or to determine by directly comparing the oil pressure in the first actuator and the oil pressure in the second actuator, A toroidal-type continuously variable transmission according to claim 1. 4. When the difference between the hydraulic pressure for driving the first actuator and the hydraulic pressure for driving the second actuator becomes equal to or greater than a predetermined value, the hydraulic pressure in the first actuator and the hydraulic pressure in the second actuator are stored in a differential valve. In this case, the differential valve is activated when the difference between the hydraulic pressure for driving the first actuator and the hydraulic pressure for driving the second actuator becomes equal to or greater than a predetermined value. The toroidal-type continuously variable transmission according to any one of claims 1 to 2, wherein the clutch is disconnected by changing the supply / discharge state of the pressure oil by displacing the differential valve body against the elasticity.