JP2002195393A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure in which deflection by speed change due to fluctuation of torque of transmitted power is restricted low to prevent feeling of disorder to a driver. SOLUTION: Supply and discharge of pressure oil to/from oil pressure type actuators 17 and 17 for speed change control are controlled by a control valve 18. Opening and closing of this control valve 18 is controlled based on signals from an axial position detection sensor 30 to detect the position of a power roller 9 and an angle detection sensor 31 to detect the oscillation angle of a trunnion 7. In this constitution, the position of the power roller 9 can be regulated as desired in transmitting torque regardless of axial displacement of pivotal shafts 6 and 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The toroidal type continuously variable transmission according to the present invention is used as a transmission unit constituting an automatic transmission for an automobile. In particular, it is an object of the present invention to reduce the discomfort given to the driver by suppressing the variation (fluctuation) of the gear ratio due to the elastic deformation of the trunnion.

[0002]

2. Description of the Related Art As an automatic transmission for an automobile, FIGS.
A toroidal type continuously variable transmission as schematically shown in FIG. This toroidal-type continuously variable transmission supports an input disk 2 concentrically with an input shaft 1 and is disposed concentrically with the input shaft 1 as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 62-71465. An output disk 4 is fixed to an end of the output shaft 3. Inside the casing 5 (see FIGS. 7 and 8 described later) containing the toroidal-type continuously variable transmission, it swings around the pivots 6, 6 which are twisted with respect to the input shaft 1 and the output shaft 3. Trunnions 7 and 7 are provided.

Each of the trunnions 7, 7 is provided with a pair of the above-mentioned pivots 6, 6 on the outer surfaces of both ends thereof, concentrically with each of the trunnions 7, 7 and one by one with each of the trunnions 7, 7. The central axis of each of the pivots 6, 6 does not intersect with the central axis of each of the discs 2, 4, but in a direction perpendicular or nearly perpendicular to the direction of the central axis of each of the discs 2, 4. It exists at a certain twist position. The center of each of the trunnions 7, 7 supports a base half of the displacement shafts 8, 8, and the trunnions 7, 8 around the pivots 6, 6.
The tilt angle of each of the displacement shafts 8, 8 can be freely adjusted by swinging the shaft 7. Power rollers 9, 9 are rotatably supported around the first half of the displacement shafts 8, 8 supported by the trunnions 7, 7, respectively. These power rollers 9, 9 are sandwiched between the inner surfaces 2a, 4a of the input and output disks 2, 4, respectively.

The inner surfaces 2a and 4a of the input and output disks 2 and 4 facing each other rotate in a circular arc centered on a point on the pivot 6 or a curve close to such a circular arc. It has a concave surface with an arc-shaped cross section. Then, the peripheral surfaces 9a, 9a of the power rollers 9, 9 formed in the spherical convex surface are connected to the inner side surfaces 2a, 4a.
Is in contact with A pressing device 10 such as a loading cam device is provided between the input shaft 1 and the input side disk 2.
The input device 2 is rotatably driven while the input device 2 is elastically pressed toward the output device 4 by the pressing device 10.

When the toroidal type continuously variable transmission configured as described above is used, the pressing device 1 is driven by the rotation of the input shaft 1.
0 rotates the input side disk 2 while pressing the input side disk 2 against the plurality of power rollers 9, 9. Then, the rotation of the input side disk 2 is transmitted to the output side disk 4 via the plurality of power rollers 9, 9, and the output shaft 3 fixed to the output side disk 4 rotates.

When the rotational speed between the input shaft 1 and the output shaft 3 is changed, and when deceleration is first performed between the input shaft 1 and the output shaft 3, each of the trunnions 7, 7 to oscillate, and the peripheral surface 9a of each power roller 9, 9;
9a is the inner surface 2a of the input side disk 2 as shown in FIG.
Are displaced in such a manner that the respective displacement shafts 8 and 8 are in contact with the portion near the center and the portion near the outer periphery of the inner surface 4a of the output side disk 4, respectively.

On the other hand, when increasing the speed, the trunnions 7, 7 are swung so that the peripheral surfaces 9a, 9a of the power rollers 9, 9, as shown in FIG. A portion of the inner surface 2a near the outer periphery and the inner surface 4 of the output disk 4
Each of the displacement shafts 8 is inclined so as to abut on the portion near the center of a. If the inclination angle of each of the displacement shafts 8, 8 is set between those in FIGS. 4 and 5, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3.

FIGS. 6 and 7 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
Are rotatably supported around the input shaft 11 having a tubular shape. A pressing device 10 is provided between the end of the input shaft 11 and the input disk 2. On the other hand, an output gear 12 is connected to the output side disk 4 so that the output side disk 4 and the output gear 12 rotate synchronously.

Axles 6, 6 provided concentrically at both ends of a pair of trunnions 7, 7 are a pair of support plates (yoke) 1
In FIGS. 3 and 13, swinging and axial directions (front and back directions in FIG. 6, FIG.
(Up and down direction) is freely supported. The displacement shafts 8, 8 are provided at the intermediate portions of the trunnions 7, 7, respectively.
It supports the base half. Each of these displacement shafts 8 and 8 makes the base half and the first half eccentric to each other. The base half of the trunnions 7 is rotatably supported in the middle of the trunnions 7, and the power rollers 9
Is rotatably supported. Also, each of the trunnions 7,
A synchronization cable 27 is crossed between the ends of the trunnions 7, so that the inclination angles of the trunnions 7, 7 are mechanically synchronized with each other.

The pair of displacement shafts 8, 8 are provided at positions opposite to the input shaft 11 by 180 degrees. or,
The direction in which the base half and the front half of each of the displacement shafts 8, 8 are eccentric is the same direction (vertical direction in FIG. 7) with respect to the rotation direction of the input side and output side disks 2, 4. .
Further, the eccentric direction is a direction substantially orthogonal to the direction in which the input shaft 11 is provided. Accordingly, the power rollers 9 are supported so as to be slightly displaceable in the direction in which the input shaft 11 is disposed.

A thrust ball bearing is provided between the outer surface of each of the power rollers 9 and 9 and the inner surface of the intermediate portion of each of the trunnions 7 and 7 in order from the outer surface of each of the power rollers 9 and 9. 14, 14 and thrust needle bearings 15, 1
5 are provided. Of these, thrust ball bearings 14, 1
4 allows the rotation of the power rollers 9 while supporting the load in the thrust direction applied to the power rollers 9. Further, each of the thrust needle bearings 15,
Reference numeral 15 denotes the first half of each of the displacement shafts 8 and 8 and the outer ring 16 while supporting the thrust load applied from the respective power rollers 9 and 9 to the outer rings 16 and 16 constituting the respective thrust ball bearings 14 and 14. , 16 are allowed to swing about the base half of each of the displacement shafts 8, 8. Further, the trunnions 7, 7 can be displaced in the axial direction of the pivots 6, 6 by hydraulic actuators (hydraulic cylinders) 17, 17.

In the case of the toroidal type continuously variable transmission configured as described above, the rotation of the input shaft 11 is transmitted to the input side disk 2 via the pressing device 10. The rotation of the input disk 2 is transmitted to the output disk 4 via the pair of power rollers 9, and the rotation of the output disk 4 is extracted from the output gear 12.

When changing the rotational speed ratio between the input shaft 11 and the output gear 12, the above-mentioned actuators 17, 1
7, the pair of trunnions 7, 7 are respectively arranged in the opposite directions, for example, the power roller 9 on the right side of FIG. 7 is on the lower side of the figure, the power roller 9 on the left side of FIG. Displace each. As a result, the direction of the tangential force acting on the contact portions between the peripheral surfaces 9a, 9a of the power rollers 9, 9 and the inner surfaces 2a, 4a of the input disk 2 and the output disk 4 changes. (Side slip occurs at the contact portion). Then, with the change in the direction of the force, the trunnions 7, 7 swing in opposite directions about the pivots 6, 6 pivotally supported by the support plates 13, 13, respectively. As a result, as shown in FIGS. 4 and 5 described above, the peripheral surfaces 9a and 9a of the power rollers 9 and the inner surfaces 2 and
a, 4a, and the rotation speed ratio between the input shaft 11 and the output gear 12 changes.

With the rotation speed ratio at a desired value,
By returning the trunnions 7, 7 to the neutral position, the abutting portions are returned to the center positions of the disks 2, 4, and the trunnions 7, 7 are caused to swing based on the side slip. Dissolve power. The magnitude of the force that swings the trunnions 7, 7 by the side slip is determined by the amount of displacement of the trunnions 7, 7 in the axial direction of the pivots 6, 6 by the actuators 17, 17. The larger the number, the larger. Therefore, when a quick shift operation is performed, each of the actuators 1
In order to increase the amount of supply and discharge of the pressure oil to and from the actuators 7 and 17 and, conversely, to perform a gradual shift operation, the amount of supply and discharge of the oil to and from each of the actuators 17 and 17 is reduced.

In any case, each of the actuators 1
The supply and discharge state of the pressure oil to and from each of the actuators 17 and 17 is performed by one control valve regardless of the number of the actuators 17 and 17 so that the movement of one of the trunnions 7 is fed back to this control valve. ing. The structure of this part is described in, for example, JP-A-6-257661, and is conventionally known. However, a second example of the conventional concrete structure, which will be described later, is shown in FIG. explain. The control valve 18 has a sleeve 20 that is displaced in the axial direction (the left-right direction in FIG. 10) by a stepping motor 19 corresponding to the speed-change driving means described in claim 2, And a spool 21 fitted displaceably. A precess cam 23 is fixed to an end of a rod 22 attached to any one of the trunnions 7, and the movement of the rod 22 is transmitted to the spool 21 via the precess cam 23 and the link arm 24. And a feedback mechanism.

When switching the gear shifting state, the sleeve 20 is displaced by a predetermined amount by the stepping motor 19 to open the flow path of the control valve 18. As a result, pressure oil is sent to the actuators 17 and 17 in a predetermined direction, and the actuators 17 and 17 are pressed.
Displaces the trunnions 7, 7 in a predetermined direction. That is, the trunnions 7, 7 swing about the respective pivots 6, 6 while being displaced in the axial direction of the respective pivots 6, 6 with the feeding of the pressure oil. Then, the movement (axial direction and swing displacement) of any one of the trunnions 7 described above.
Is a precess cam 23 fixed to the end of the rod 22
And the link arm 24 to the spool 21 to displace the spool 21 in the axial direction. As a result, with the trunnion 7 displaced by a predetermined amount, the flow path of the control valve 18 is closed, and the actuator 1
The supply and discharge of the pressure oil to and from the pumps 7 and 17 are stopped. Therefore, the amount of displacement of each of the trunnions 7, 7 in the axial direction and the swinging direction only depends on the amount of displacement of the sleeve 20 by the stepping motor 19.

At the time of power transmission by the toroidal type continuously variable transmission, the power rollers 9 are displaced in the axial direction of the input shaft 11 based on the elastic deformation of the components. Then, the respective displacement shafts 8 supporting the respective power rollers 9 slightly rotate about the respective base halves. As a result of this rotation, each of the thrust ball bearings 14, 1
4 and the outer surfaces of the outer races 16, 16 and the respective trunnions 7, 7
Relatively displaces with the inner surface. Since the thrust needle bearings 15, 15 exist between the outer surface and the inner surface, the force required for the relative displacement is small.

Further, in order to increase the transmittable torque, as shown in FIGS. 8 to 10, two input disks 2A and 2B and two output disks 4 and 4 are provided around the input shaft 11a. A so-called double-cavity type structure in which two input disks 2A and 2B and two output disks 4 and 4 are arranged in parallel with respect to the power transmission direction is also conventionally known. The structure shown in FIGS. 8 to 10 supports an output gear 12a around an intermediate portion of the input shaft 11a so as to freely rotate with respect to the input shaft 11a, and a cylindrical portion provided at the center of the output gear 12a. The output disks 4 are spline-engaged at both ends.
Each of the input side disks 2A and 2B is connected to the input shaft 1
The input shaft 11a is rotatably supported at both ends of the shaft 1a. The input shaft 11a is driven by the drive shaft 25
It is rotationally driven via a loading cam type pressing device 10.

In the case of the toroidal type continuously variable transmission of the double cavity type as described above, the transmission of power from the input shaft 11a to the output gear 12a is performed between one input side disk 2A and the output side disk 4. And the other input side disk 2B
And the output side disk 4 is divided into two systems, so that large power can be transmitted. In the case of such a double-cavity toroidal-type continuously variable transmission, the trunnions 7, 7 are displaced in the axial direction of the pivots 6, 6 by the hydraulic actuators 17, 17 during gear shifting. As described above, only one control valve 18 is provided in the entire toroidal-type continuously variable transmission for controlling the supply and discharge of the pressure oil to and from the actuators 17 for shifting. And
This one control valve 18 allows a plurality of actuators 1
The supply and discharge of pressure oil to and from 7, 17 are controlled.

[0020]

The toroidal type continuously variable transmission as described above uses a control valve 18 provided with a precess cam 23.
Regardless of the opening / closing control of the engine, the gear ratio unnecessarily fluctuates with the input torque due to the effects of the assembly gap and elastic deformation of the components of the toroidal type continuously variable transmission, and the engine speed suddenly increases. The experiment by the inventors of the present invention has revealed that there is a possibility that the driver may feel uncomfortable. According to experiments conducted by the present inventors, the change in the gear ratio is caused by the fact that the displacement of the precess cam 23 does not always accurately represent the displacement of the power rollers 9 and 9. Do you get it. This will be described below.

As shown in FIG. 10 described above, the precess cam 23 is attached to one of the trunnions 7 at its base end (FIG. 10).
10 (see FIG. 10).
At the lower end of the frame). On the other hand, during operation of the toroidal-type continuously variable transmission, the trunnion 7 receives a large force from the power roller 9 supported on the inner side. This force is mainly of the following two types. The peripheral surface 9a of the power roller 9 and the input side disks 2, 2
A, 2B inner surface 2a and output side disk 4 inner surface 4
a force applied from the abutting portion (traction portion) with a in accordance with power transmission. Pressing device 10 (for example, see FIGS. 8 and 9)
A thrust load that presses the power roller 9 against the inner surface of the trunnion 7 based on the pressing force of the power roller 9. All of these forces cause the position of the precess cam 23 to shift from the normal position.

First, the reason why the position of the precess cam 23 deviates from the normal position due to the above-mentioned force will be described with reference to FIG.
This will be described with reference to 1 to 12. Among them, FIG. 11 shows one of the ones arranged between a pair of input side disks and output side disks.
A pair of trunnions 7, 7 and both trunnions 7,
7, displacement shafts 8, 8, power rollers 9, 9, rods 22, pistons 26, 26 constituting a hydraulic actuator, and a precess cam 23.
Are simply shown. In FIG. 11, the input side disk not shown in FIG. 11 rotates clockwise as indicated by an arrow α. Therefore, the output side disk, also not shown in FIG. 11, rotates counterclockwise.

FIG. 11A shows a case where power is not transmitted between the input side disk 2 and the output side disk 4 (for example, see FIG. 6). In this case, the load applied to each of the power rollers 9, 9 from the inner side surfaces 2a, 4a (for example, see FIG. 6) of the input side disk 2 and the output side disk 4 is zero. Accordingly, the load applied to the displacement shafts 8 and 8 supporting the power rollers 9 and 9 and the trunnions 7 and 7 is also zero, and the displacement shafts 8 and 8 are inclined or the trunnions 7 and 7 are inclined.
7 does not deform elastically. For this reason, the precess cam 23 fixed to the end of the rod 22 attached to one of the trunnions 7 (to the right in FIG. 11) is located at the regular position indicated by the chain line A in FIG.

FIG. 11B shows a case where relatively light power is transmitted between the input side disk 2 and the output side disk 4. In this case, the trunnions 7, 7 are provided at both ends of the trunnions 7, 7 based on the loads applied to the power rollers 9, 9 from the inner side surfaces 2a, 4a of the input disk 2 and the output disk 4. A load is applied in the axial direction (vertical direction in FIG. 11) of the pivots 6, 6 (for example, see FIG. 10). The actuator 1 incorporating the pistons 26, 26 to support this load.
The hydraulic pressure is raised to 7, 17 (for example, see FIG. 10). At the same time, based on the load applied to the power rollers 9, 9 from the disks 2, 4, the displacement shafts 8, 8, which support the power rollers 9, 9, are moved to the positions shown in FIG.
As shown in FIG. 12 (B) and in an exaggerated manner, the input disk 2 is inclined forward in the direction in which the load applied to the power rollers 9 is applied.

Such an inclination is caused by radial needle bearings 28, 2 provided between both ends of the displacement shafts 8, 8 and the power rollers 9, 9 and the trunnions 7, 7.
9 (FIG. 12) and the elastic deformation of the displacement shafts 8, 8 themselves. Although such inclination is slight, each of the power rollers 9, 9 and each of the trunnions 7,
7 is carried out with a relatively light force based on the existence of the internal clearances of the thrust ball bearing 14 and the thrust needle bearing 15 (FIG. 12) provided between the thrust ball bearing 14 and the thrust needle bearing 15.

When the displacement shafts 8, 8 are tilted in this manner, the power rollers 9, 9 supported by the displacement shafts 8, 8 are driven by the input and output disks 2, 4, respectively.
Is displaced with respect to. Each of these power rollers 9, 9
Peripheral surfaces 9a, 9a and inner surfaces 2 of these two disks 2, 4
a, 4a, the position of the contact portion (traction portion) is shifted from the center position of these two disks 2, 4. When the traction portion deviates from the center position of the two disks 2 and 4 in this manner, the peripheral surfaces 9a and 9a
Side slip occurs at the traction portion between the inner surfaces 2a and 4a of the disks 2 and 4. Then, based on such a side slip, a known feedback mechanism operates to return the traction portion to the center position between the disks 2 and 4.

That is, based on the side slip, the respective trunnions 7, 7 together with the respective power rollers 9, 9 are oscillated about the pivots 6, 6, and the precess cam 23 is controlled via the link arm 24. The spool 21 of the valve 18 (see FIG. 10) is displaced. Then, pressure oil is supplied to and discharged from the actuators 17, 17 to displace the trunnions 7, 7 in the axial direction of the pivots 6, 6, and return the traction portion to the central position of the disks 2, 4. . At this time, since no command signal for shifting has been issued, the sleeve 20 (see FIG. 10) of the control valve 18 remains at the same position (does not displace in the axial direction). As a result, each of the power rollers 9 performs a shift operation even though a command signal for shifting is not output. Then, the precess cam 23, the offset from the normal position shown by a chain line b in the axial direction by [delta] _1, will be present in a chain line B position.

FIG. 11C shows a case where a large power is transmitted between the input side disk 2 and the output side disk 4. In this case, not only the above-mentioned force but also the above-mentioned force acts in a direction to shift the position of the precess cam 23 from the normal position. That is, in the state shown in FIG. 11C, the inclination of each of the displacement shafts 8 becomes larger than in the case of FIG. 11B, and at the same time, the elastic deformation of each of the trunnions 7, 7 cannot be ignored. become.
In this case, the middle part of each of these trunnions 7, 7
Based on the thrust load applied from each of the power rollers 9, 9, as shown in FIG. 11C and FIG. 13 in an exaggerated manner, the inner surface side where these power rollers 9, 9 are installed becomes concave. Elastically deform. Then, based on this elastic deformation, the total length of the trunnions 7, 7 in the axial direction of the pivots 6, 6 is reduced. More specifically, the longitudinal end faces of the trunnions 7, 7 are displaced in a direction approaching the longitudinal central portions of the trunnions 7, 7.

As a result of this displacement, the precess cam 23 is further deviated from the normal position shown by the dashed line A by δ ₂ compared to the case of FIG. That is,
In this state, the deviation of the precess cam 23 from the normal position is (δ ₁ + δ ₂ ). The contact portion (traction portion) between the peripheral surfaces 9a, 9a of the power rollers 9, 9 and the inner side surfaces 2a, 4a of the input side and output side disks 2, 4 is (δ ₁ + δ _2). ) From the center of the disks 2 and 4. As a result, each of the power rollers 9, 9 performs the shift operation by the amount of (δ ₁ + δ ₂ ) even though the command signal for the shift is not output. The new displacement δ ₂ is the sum of the portion based on the elastic deformation of the trunnion 7 and the portion based on the further increase in the inclination angle of the displacement shaft 8.

As described above, in the cases shown in FIGS. 11B and 11C, the shift operation is performed in spite of the fact that the command signal for the shift is not output. Is proportional to the axial deviation {δ ₁ or (δ ₁ + δ ₂ )} and the cam lead of each of the precess cams 23. For example, assuming that the cam lead is 20 mm / 360 degrees, when the deviation is 0.3 mm, each of the power rollers 9 is 5.4.
Tilting (oscillating displacement about the pivots 6 and 6).
Therefore, it is important to suppress the displacement of the precess cam 23 from the viewpoint of suppressing an unintended shift operation based on the above-described cause.

The unintended shifting operation also occurs due to the deflection of the rod 22 due to the elastic deformation of the trunnion 7 on which the precess cam 23 is installed. In this regard,
This will be briefly described with reference to FIG. At the time of power transmission, the trunnion 7 is elastically deformed in an exaggerated manner in FIG. 13 in a direction in which the inner surface becomes concave, based on a thrust load received from the power roller 9 supported on the inner surface. Then, based on this elastic deformation, the rod 22 having its base end (the upper end in FIG. 13) fixedly connected to the end of the trunnion 7 is displaced. Then, the distal end portion of the rod 22 to which the precess cam 23 is attached (the lower end portion in FIG. 13).
As for the above, the displacement amount in the radial direction increases as the thrust load increases. Such a displacement also causes the unintended shifting operation to be performed.

If the above-mentioned precess cam 23 is installed on the trunnion 22 on the opposite side to the case shown in FIG. 11 and the displacement based on the above-mentioned force and the displacement based on the above-mentioned force cancel each other, an unintended shift can be performed. Can be suppressed to some extent. However, even in this case, an unintended speed change operation is performed, though to a lesser extent. FIG. 14 shows a structure in which the precess cam 23 is installed on the trunnion 22 on the opposite side to that of FIG. 11, and the magnitude of the torque input to the toroidal-type continuously variable transmission is different from the speed ratio of the toroidal-type continuously variable transmission. The result of the experiment performed to know the influence is shown. In this experiment, while the signal for maintaining the speed ratio of the toroidal type continuously variable transmission constant (constant speed state 1) was given,
The torque input to the toroidal-type continuously variable transmission was gradually increased. In FIG. 14 showing the results of such an experiment, the horizontal axis represents the elapsed time, the vertical axis represents the input torque or the gear ratio, the curve a represents the magnitude of the torque, and the curve b represents the actual gear ratio. ing.

As is clear from FIG. 14 showing the results of such an experiment, the power rollers 9 and
In the case of the structure for detecting the displacement of No. 9, there is a limit in accurately regulating the gear ratio as desired. Therefore, when a large torque is to be transmitted by a toroidal-type continuously variable transmission incorporating the precess cam 23, a somewhat unexpected shift operation is performed. In any case, if an unintended shift operation is performed, the engine speed changes suddenly at that moment, giving the driver a sense of discomfort. It is important to minimize such unintended shifting operations as much as possible from the viewpoint that stable driving is performed and the driver does not feel uncomfortable. In view of such circumstances, the present invention has been made to suppress the degree of unintended shift operation.

[0034]

The toroidal-type continuously variable transmission according to the present invention comprises a first disk and a second disk and a plurality of trunnions, similarly to the above-described conventionally known toroidal-type continuously variable transmission. , A displacement axis, a power roller,
A hydraulic actuator and a control valve are provided. Among these, the first disk and the second disk are rotatably supported concentrically with each other with their inner surfaces facing each other, each having a concave surface having an arc-shaped cross section.
Each of the trunnions swings about a pivot axis which is twisted with respect to the central axes of the first and second disks. The displacement shaft is supported at an intermediate portion of each of the trunnions in a state of protruding from the inner surface of each of the trunnions. The power roller is disposed on the inner surface side of each of the trunnions and is rotatably supported around each of the displacement shafts while being sandwiched between the first and second disks. The peripheral surface is a spherical convex surface. Also, the hydraulic actuator is
Provided for each trunnion, by displacing each of these trunnions in the axial direction of each of the pivots, these trunnions are rockingly displaced about these respective pivots, and the first disc and the second disc are displaced. Is changed. Further, the control valve is for switching the supply / discharge state of the pressure oil to / from each of the actuators. By providing a feedback mechanism for transmitting the displacement of any trunnion or a member displaced together with the trunnion to the control valve, the movement of the trunnion is transmitted to the control valve so that the supply / discharge state of the control valve can be switched. I have. In particular, in the toroidal-type continuously variable transmission of the present invention, an axial position sensor, an angle detection sensor,
An arithmetic unit and feedback-side driving means are provided. Among these, the axial position detection sensor is supported by a fixed portion, and is related to the axial direction of each of the pivots on the peripheral surface of a power roller supported on the inner surface of any trunnion or a member concentric with the power roller. Detect the position. The angle detection sensor detects a swing angle of any trunnion about each of the pivots. Further, the computing unit calculates a state to be set for the control valve based on detection signals of the angle detection sensor and the axial position detection sensor. Further, the feedback side driving means drives the control valve based on a calculation result of the arithmetic unit.

[0035]

According to the toroidal-type continuously variable transmission of the present invention configured as described above, it is possible to suppress a change in the gear ratio during power transmission and to eliminate a sense of discomfort given to the driver. That is, in the case of the toroidal-type continuously variable transmission of the present invention, the axial position sensor detects the position of the peripheral surface of the power roller or a member concentric with the power roller in the axial direction of each pivot. Therefore, the position of the power roller in the axial direction of each of the pivots can be accurately regulated. That is, when the shift operation is not performed, the position of the power roller is accurately regulated to the center position between the first and second disks, so that an unintended shift operation can be prevented. Further, when performing the shifting operation, the amount of deviation of the position of each power roller from the center position can be accurately regulated so that the shifting can be performed at a desired speed. The gear ratio based on the inclination of the trunnion supporting the power roller is:
Since the angle detection sensor directly detects, an accurate gear ratio as desired can be obtained.

[0036]

1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. FIG. still,
A feature of the toroidal-type continuously variable transmission of the present invention is to devise a structure for detecting the positions or postures of the power rollers 9, 9 and the trunnions 7, 7, in order to suppress unexpected fluctuations in the speed ratio during power transmission. On the point. The structure of the parts shown in the other drawings and the operation of transmitting power between the input part and the output part or changing the speed ratio between the input part and the output part are described in the above-mentioned figures. Since it is the same as the conventionally known toroidal-type continuously variable transmission shown in FIGS.
Description of the equivalent parts is omitted.

The toroidal-type continuously variable transmission according to the present invention includes an axial position detection sensor 30, an angle detection sensor 31, a calculator 32, and a feedback-side driving means (not shown) such as a stepping motor. The axial position detection sensor 30 is a casing 5 (FIG. 7) which is a fixed part.
8), and a power roller 9 supported on the inner surface of any of the trunnions 7 (left side in FIG. 1).
Of the peripheral surface 9b in the axial direction of each of the pivots 6, 6 is detected. The peripheral surface 9 of the power roller 9 in this case
b is the inner side surface 2 of both the input side and output side disks 2 and 4
a, 4a (see, for example, FIG. 6), not a spherical convex peripheral surface 9a portion, but a cylindrical surface portion formed on the outer surface side of the peripheral surface 9a.

The axial position detection sensor 30 includes:
In addition to various contact sensors, a non-contact sensor such as a capacitance type or an optical non-contact sensor such as a laser can be used. In particular, since the position of the peripheral surface 9b of the power roller 9 which rotates at a high speed during use is detected, a capacitance type or optical non-contact type sensor can be preferably used. In order to enable the position of the peripheral surface 9b to be detected by such an axial position detection sensor 30, an insertion hole 33 is provided in a part of the pivot 6 provided at one end (upper end in FIG. 1) of the trunnion 7. The pivot 6 is formed so as to penetrate in the axial direction. The axial position detection sensor 30 is supported on an inner surface of the casing 5 by a support bracket (not shown), and has a detection surface facing the peripheral surface 9b.

Note that, regardless of the rotation of the pivot 6 caused by the swing displacement of the trunnion 7, the axial position detection sensor 3
In order to prevent the inner surface of the insertion hole 33 from interfering with the inner surface of the insertion hole 33, the insertion hole 33 may have a sufficiently large inner diameter, or may have an arc shape having the center axis of the pivot 6 as its center. Formed. Further, when the axial position detecting sensor 30 is fixed and the power roller 9 is freely oscillatingly displaceable together with the trunnion 7, even if the power roller 9 is not displaced in the axial direction of the pivot 6, The distance between the detection surface of the position detection sensor 30 and the peripheral surface 9b changes. However, a mathematical relationship is established between the change in distance and the swing angle of the power roller 9 in this case.
Therefore, the distance change based on the swing is corrected (the distance change based on the swing is canceled) based on the detection signal of the angle detection sensor 31 described below.

On the other hand, the support bracket that supports the axial position detection sensor 30 can be made swingable in synchronization with the trunnion 7. In this case, the insertion hole 33 only needs to have an inner diameter that allows the axial position detection sensor 30 to be loosely inserted, and the measured value of the axial position detection sensor 30 is used as the angle detection sensor 31.
It is not necessary to perform the work of correcting based on the detected value of. Note that the displacement of the power roller 9 due to the swing of the displacement shaft 8 (the swing of the first half centered on the base half) due to the torque fluctuation is as follows.
Again, it is a factor based on unexpected change in gear ratio,
In the case of the present invention, this displacement is also detected. Therefore, it is possible to suppress a change in the gear ratio based on the displacement.

The angle detection sensor 31 detects the swing angle of any one of the trunnions 7 about each of the pivots 6. In the case of this example, the angle detection sensor 31 is
It is attached to the distal end of a rod 22 having its base end connected to the same trunnion 7 as the above-mentioned axial position detection sensor 30 is attached. However, the trunnion 7 provided with the axial position detection sensor 30 and the trunnion 7 provided with the angle detection sensor 31 do not necessarily have to be the same trunnion 7. The position where the angle detection sensor 31 is mounted does not necessarily need to be the rod 22 portion. If a configuration is adopted in which the swing angle of any of the pivots 6 is measured by an angular displacement sensor provided in the vicinity of the support plate 13 supporting the pivot 6, the influence of the elastic deformation as shown in FIG. And accurate angle detection can be performed.
In any case, the angle detection sensor 31 includes a rotary encoder, an optical angle detection device, an angle detection mechanism combining a cam and a displacement meter, and the like, and the swing of the trunnion 7 about each of the pivots 6, 6. Use one that can detect angles with high accuracy.

The computing unit 32 controls the supply and discharge of pressure oil to and from the hydraulic actuators 17 based on the detection signals of the axial position detection sensor 30 and the angle detection sensor 31. The state of the control valve 18 to be set is calculated. Then, a feedback driving means such as a stepping motor (not shown) drives the control valve 32 based on the calculation result of the calculator 32.

In the case of the present embodiment, the control valve 32 is inserted into the cylindrical sleeve 20 and inside the sleeve 20 so as to be freely displaceable in the axial direction, as in the case of the conventional structure shown in FIG. And a spool 21. The flow path is switched based on the relative displacement of the sleeve 20 and the spool 21 in the axial direction, and the actuator 1
The state of supply and discharge of the pressure oil to and from the switches 7 and 17 is switched. In the case of this example, the sleeve 20 of the sleeve 20 and the spool 21 can be axially displaceably driven by a stepping motor 19 for speed change control (see FIG. 10).
That is, the stepping motor 19 displaces the sleeve 20 in the axial direction so as to switch the flow path of the control valve 32 based on a shift command. On the other hand, the spool 21 can be axially displaceably driven by a second stepping motor (not shown) that is a feedback-side driving unit. That is, the second stepping motor controls the spool 21 so as to feed back the state of the power roller 9 obtained based on the detection signals of the axial position detection sensor 30 and the angle detection sensor 31 to the control valve 32. Is displaced in the axial direction. The displacement between the spool 21 and the sleeve 20 may be reversed from that shown in the figure.

According to the toroidal type continuously variable transmission of the present invention configured as described above, the displacement of the power roller 9 based on the above-described force and the precess cam 23 (also based on the above-described force). (See FIG. 10) can be prevented from being linked to a change in the gear ratio, and the discomfort given to the driver can be eliminated. That is, in the case of the toroidal type continuously variable transmission of the present invention, the axial position detection sensor 30 detects the position of the peripheral surface 9b of the power roller 9 in the axial direction of each of the pivots 6, 6. Therefore, each of these pivots 6,
6, the position of the power roller 9 in the axial direction can be accurately regulated. That is, even when the power roller 9 is displaced in the axial direction of each of the pivots 6 based on the above-mentioned force, the power roller 9
Can be detected. Therefore, when the shift operation is not performed, the position of the power roller 9 is accurately regulated to the center position between the input side and output side disks 2 and 4, thereby preventing an unintended shift operation. .

More specifically, if the position of the power roller 9 is deviated from the center position of the disks 2 and 4 even though no command to shift is issued, the axial position detection is performed. Based on a signal from the sensor 30 (and, if necessary, a signal from the angle detection sensor 31), the computing unit 32 sends the second stepping motor to the trunnions 7, 7 in a direction to eliminate the displacement.
Signal to be displaced. Then, based on this signal, the second stepping motor turns the spool 21
Are displaced in the axial direction, and the actuators 17, 17
As a result, the trunnions 7, 7 are displaced in the axial direction of the pivots 6, 6 by an amount corresponding to the displacement. In the state where the displacement of the trunnions 7 has been eliminated in this manner, the calculation is performed based on the signal from the axial position detection sensor 30 (and, if necessary, the signal from the angle detection sensor 31). The device 32 sends a signal to the second stepping motor to displace the spool 21 in the axial direction so as to close the flow path of the control valve 18. As a result, each trunnion 7,
7 stops.

As described above, in the case of the toroidal type continuously variable transmission of this embodiment, the position of the power roller 9 in the axial direction of each of the pivots 6, 6 is defined as the position of the peripheral surface 9b of the power roller 9. Since the direct detection is performed, the fluctuation of the gear ratio can be suppressed regardless of the displacement of the power roller 9 due to the fluctuation of the input torque. Further, since the precess cam 23 is not used, a change in the gear ratio due to the displacement of the precess cam 23 can be prevented. FIG. 2 is a numerical experiment (computer simulation) performed by the present inventor to confirm the effect of the present invention.
Shows the results. In FIG. 2 showing the results of such numerical experiments, the horizontal axis represents the elapsed time, the vertical axis represents the input torque or the gear ratio, the solid line A represents the magnitude of the input torque, the broken line B represents the actual gear ratio, Each is represented. As is clear from FIG. 2 showing the results of such numerical experiments, according to the present invention, an unexpected shift can be suppressed so that the driver cannot understand at all.

On the other hand, when performing a shift operation,
The two disks 2, at the positions of the power rollers 9, 9,
The shift amount from the center position of No. 4 can be accurately regulated so that the shift can be performed at a desired speed. The gear ratio based on the inclination of each of the trunnions 9, 9 supporting the power rollers 9, 9 is directly detected by the angle detection sensor 31, so that a desired accurate gear ratio can be obtained. That is, at the time of shifting, the stepping motor 19 causes the sleeve 20 to move the sleeve 20 in a predetermined direction determined by the shifting direction (deceleration direction or speed-up direction) based on a signal from a controller (not shown). The shaft is displaced in the axial direction by a predetermined amount (predetermined length) determined by a required speed of the shift (whether the shift is performed rapidly or gradually).

As a result, each of the actuators 17, 1
7 displaces each of the trunnions 7, 7 in the axial direction of each of the pivots 6, 6 by an amount corresponding to the predetermined length, and displaces the peripheral surfaces 9a, 9a of the power rollers 9, 9 with the input side. ,
The contact positions of the output side disks 2 and 4 with the inner side surfaces 2a and 4a are shifted from the center position of the both disks 2 and 4. As a result, the trunnions 7, 7 supporting the power rollers 9, 9 are displaced in a predetermined direction at a predetermined speed by the force based on the side slip as described above, which acts on each of the contact portions. . Then, based on the signal from the angle detection sensor 31, the stepping motor 19 causes the sleeve 20 to move in the opposite direction by the same amount in a state where the trunnions 7, 7 are swung by an amount corresponding to the desired gear ratio. move. Then, the trunnions 7, 7 are returned by the same length in the opposite direction by the actuators 17, 17, and the contact position is returned to the center position. Next, the controller sends a signal to the stepping motor 19 to displace the sleeve 20 in the axial direction so as to close the flow path of the control valve 18. As a result, each of the trunnions 7, 7 stops in a state where the desired gear ratio is attained.

Next, FIG. 3 shows a second example of the embodiment of the present invention, which also corresponds to claims 1 and 2. In the case of this example, the axial position detection sensor 30 is opposed to the outer peripheral surface of the retainer 34 constituting the thrust ball bearing 14 provided between the inner surface of the trunnion 7 and the outer surface of the power roller 9. . The retainer 34 is provided concentrically with the power roller 9 and is displaced in synchronization with the displacement of the power roller 9. Therefore, by making the detection surface of the axial position detection sensor 30 face the outer peripheral surface of the retainer 34, the position of the power roller 9 with respect to the axial direction of the pivots 6, 6 provided on both end surfaces of the trunnion 7 is obtained. Can be accurately detected. Since the outer circumferential surface of the retainer 34 substantially faces the center of the pivot 6, an insertion hole 33a for inserting the axial displacement sensor 30 is formed in the center of the pivot 6. . 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 practicing the present invention, each of the axial position detecting sensor 30 and the angle detecting sensor 31 is one.
It is sufficient to provide them individually, but it is not necessarily limited to only one.
Two or more of each may be provided. For example, two or more sensors 30, 31 of one or both of the axial position detection sensor 30 and the angle detection sensor 31 may be provided, and the detection signals of the sensors 30, 31 may be compared. In this case, when an abnormality such as the displacement of the power rollers 9 is not synchronized, the clutch between the engine and the toroidal type continuously variable transmission is disengaged, and the toroidal type continuously variable transmission is disengaged. Measures to prevent the occurrence of unrecoverable serious failures. Further, the detection surface of the axial position detection sensor 30 may be opposed to the outer peripheral surface of the outer ring 16 of the thrust ball bearing 14.

[0051]

Since the present invention is constructed and operates as described above, it is possible to realize a toroidal-type continuously variable transmission which does not give a driver an uncomfortable feeling without particularly troublesome control.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing the results of a numerical experiment.

FIG. 3 is an essential part cross-sectional view showing a second example of the embodiment of the present invention.

FIG. 4 is a schematic side view showing a basic structure of the toroidal-type continuously variable transmission in a state of maximum deceleration.

FIG. 5 is a schematic side view similarly showing a state at the time of maximum speed increase.

FIG. 6 is an essential part cross-sectional view showing a first example of a specific structure of the toroidal type continuously variable transmission.

FIG. 7 is a sectional view taken along line xx of FIG. 6;

FIG. 8 is an essential part cross-sectional view showing a second example of the specific structure of the toroidal-type continuously variable transmission.

FIG. 9 is a sectional view taken along line yy of FIG. 8;

FIG. 10 is a cross-sectional view of the same zz.

FIG. 11 is a schematic diagram for explaining the reason why the gear ratio greatly changes in the conventional structure.

FIG. 12 is a cross-sectional view of the trunnion, the rod, and the power roller, exaggeratingly showing the displacement state of the power roller with respect to the trunnion.

FIG. 13 is a cross-sectional view of the trunnion and the rod for explaining the reason why the elastic deformation of the trunnion is linked to fluctuation (change) of the gear ratio.

FIG. 14 is a diagram showing the results of an experiment performed to determine the effect of a change in input torque on a gear ratio in a conventional structure.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2, 2A, 2B input side disk 2a inner surface 3 output shaft 4 output side disk 4a inner surface 5 casing 6 pivot 7 trunnion 8 displacement shaft 9 power rollers 9a, 9b peripheral surface 10 pressing device 11, 11a input shaft 12 , 12a Output gear 13 Support plate 14 Thrust ball bearing 15 Thrust needle bearing 16 Outer ring 17 Actuator 18 Control valve 19 Stepping motor 20 Sleeve 21 Spool 22 Rod 23 Precess cam 24 Link arm 25 Drive shaft 26 Piston 27 Synchronous cable 28 Radial needle bearing 29 Radial Needle bearing 30 Axial position detection sensor 31 Angle detection sensor 32 Computing device 33, 33a Insertion hole 34 Cage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J051 AA03 AA08 BA03 BB02 BD02 BE09 CA05 CB07 DA02 DA05 DA06 DA09 EA08 EB01 ED01 ED12 FA02 3J552 MA09 NA01 NB01 PA14 PA54 QA24C QC07 RA02 SA46 TA01 TB13 VA24Y VA26Y

Claims (2)

[Claims] 1. A first disk and a second disk which are concentrically and rotatably supported in a state where their inner surfaces, each having a concave cross-section having an arc-shaped cross section, face each other; A plurality of trunnions swinging about a pivot axis which is twisted with respect to the center axis of the disc and the second disc, and a displacement supported at a middle portion of each of the trunnions so as to protrude from the inner surface of each of the trunnions. A shaft, which is arranged on the inner surface side of each of these trunnions and is rotatably supported around each of the displacement shafts while being sandwiched between the first disk and the second disk, has a spherical peripheral surface. A power roller having a convex surface and a trunnion are provided for each trunnion, and each trunnion is displaced in the axial direction of each of the pivots so that the trunnions swing about the pivots. A hydraulic actuator for changing the speed ratio between the first disk and the second disk, and a control valve for switching the supply / discharge state of pressure oil to / from each of the actuators. By providing a feedback mechanism for transmitting the displacement of the trunnion or a member that is displaced together with the trunnion to the control valve, the movement of the trunnion is transmitted to the control valve, and the supply / discharge state of the control valve can be switched freely. In the step transmission, a power roller supported on a fixed portion and supported on an inner surface of any trunnion or a position of a peripheral surface of a member concentric with the power roller in the axial direction of each of the pivots is detected. An axial position detecting sensor, an angle detecting sensor for detecting a swing angle of any trunnion about each of the pivots, and an angle detecting sensor for detecting the angle. A computing unit that calculates a state to be set for the control valve based on the detection signal of the sensor and the axial position detection sensor; and a feedback drive unit that drives the control valve based on a calculation result of the computing unit. A toroidal type continuously variable transmission characterized by having The control valve includes a cylindrical sleeve and a spool inserted inside the sleeve so as to be axially displaceable, and a flow path is formed based on a relative displacement between the sleeve and the spool in the axial direction. By switching between the supply and discharge states of the hydraulic oil to and from each hydraulic actuator. The drive unit for shifting the flow path of the control valve based on a shift command causes the drive between the sleeve and the spool to be switched. 2. The toroidal type according to claim 1, wherein one of the members is freely displaceable and driven in the axial direction, and the other one of the sleeve and the spool is freely displaceably driven in the axial direction by feedback-side driving means. Continuously variable transmission.