JPH09292001A - Hydraulic control device for toroidal type continuously variable transmission - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To suppress vibration of a roller supporting member even when disturbance is applied to a power roller. SOLUTION: A plurality of power rollers 2 and 3 which can be tilted by being sandwiched by a surface facing an input disk and an output disk.
And eccentric shafts 6 that respectively support the power rollers, and are provided with trunnions 4 and 5 that are rotatable about the axes and axially displaceable, and hydraulic cylinders 1A and 1B that drive the trunnions 4 and 5. The shift control valve 41 for controlling the hydraulic pressure to the cylinders 1A, 1B and the recess cam 35 for transmitting the rotation amount of the trunnion 4 to the shift control valve 41 and feeding back the actual speed ratio are provided. The hydraulic pressure of the trunnion 4 including the precess cam 35 is provided. Oil passages 7H and 7L that connect the cylinder 1A and the shift control valve 41, and the trunnion-side hydraulic cylinder 1B.
The hydraulic oil is independently supplied and discharged via the 8H and 8L oil passages that communicate with the shift control valve 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hydraulic control device for a toroidal type continuously variable transmission used for a vehicle or the like.

[0002]

2. Description of the Related Art A hydraulic control device for a toroidal type continuously variable transmission adopted in a vehicle such as an automobile is disclosed in Japanese Patent Application Laid-Open No. 2-2.
The one disclosed in Japanese Patent Publication No. 83949 is known.

To explain this, as shown in FIGS. 8 to 10, the toroidal type continuously variable transmission is sandwiched by a pair of input / output disks 12 and 13 having toroidal grooves formed on opposing surfaces 12a and 13a. Pair of power rollers 2, 3
The power rollers 2 and 3 are formed of a single cavity having a pair of trunnions 4 and 5 that are erected at predetermined intervals with the rotation shafts of the input / output disks 12 and 13 interposed therebetween.
(Roller support member) is rotatably supported by eccentric shafts 6, 6 whose base ends are supported, and tilts (Y in FIG. 9).
It is supported around the axis = φ [deg]).

Power transmission by these power rollers 2 and 3 sandwiches the power rollers 2 and 3 with a large force between the input and output disks by the loading cam 15, and the power rollers 2 and 3 and the input and output disks 12 and 13 are sandwiched. The torque input to the input shaft 11 is transmitted to the hollow output gear 14 by the shearing force of the oil film. The force acting during power transmission is proportional to the difference between the velocity vectors of the input / output disks 12 and 13 and the power rollers 2 and 3 at the contact point. Then, shifting of the continuously variable transmission is performed by tilting the power rollers 2 and 3 to change the radius ratio of the input / output disks 12 and 13 at the contact point.
As shown in FIG. 9, this gear ratio control supports the trunnions 4 and 5 so as to be displaceable in the Y-axis direction and the Y-axis direction, and drives the trunnions 4 and 5 in the Y-axis direction. 1B is provided.

Hydraulic cylinder 1A for driving the trunnion 4
Oil chambers 33B and 33A are defined above and below the piston 31 of FIG. 1, while oil chambers 34A and 34A are provided above and below the piston 32 of the hydraulic cylinder 1B that drives the trunnion 5.
B is defined, and the oil chamber 33A below the hydraulic cylinder 1A and the oil chamber 34A above the hydraulic cylinder 1B communicate with each other via the oil passage 90L, while the oil chamber 33 above the hydraulic cylinder 1A.
B and the oil chamber 34B below the trunnion 5 communicate with each other via the oil passage 90H, and the trunnions 4 and 5 are driven in the directions opposite to each other.

The shift control valve 41 'for controlling the hydraulic pressure supplied to the oil passages 90H, 90L is provided with a sleeve 42' and a spool 43 which are relatively displaceable in the axial direction, and one of them is not shown via an actuator 50. It is controlled by the shift controller, and the other feeds back the displacement (actual gear ratio) of the rod 24 protruding from the lower end of the trunnion 4.
Here, the case where the sleeve 42 ′ is driven by the actuator 50 is shown. In addition, a recess cam 35 having a predetermined inclined surface is formed at the lower end of the rod 24, and the rod 24 is connected via a link 36 slidingly contacting the recess cam 35.
The displacement, that is, the actual gear ratio is fed back to the spool 43.

In the housing of the shift control valve 41 ', a line pressure port 9 communicating with the hydraulic pressure supply means, a port 47 communicating with the oil passage 90H and a port 48 communicating with the oil passage 90L.
Is opened, and the pressure oil from the line pressure port 9 is selectively supplied to the port 47 or 48, while the pressure oil of the other circuit is arranged in a tank (not shown).

The sleeve 42 'is driven according to the target speed ratio determined by the speed change controller, while the spool 43' is driven.
Is a tilt angle (actual gear ratio) of the power roller 2 and the trunnion 4 due to the effect of a predetermined inclined surface of the precess cam 35.
When the relative positional relationship between the sleeve 42 ′ and the spool 43 is deviated by being driven in the axial direction in accordance with the axial displacement amount of the valve chamber 44 A formed in the sleeve 42 ′ facing the ports 47 and 48, Pressure oil is supplied and discharged from 44B,
Pressure oil is supplied and discharged between the line pressure port 9 and the tank and the hydraulic cylinders 1A and 1B so that the actual speed ratio matches the target speed ratio.
A force corresponding to the pressure difference between the upper and lower oil chambers of 32 is applied to adjust the tilt angle of the power rollers 2 and 3 (angle φ around the Y axis in the figure).

[0009]

By the way, in the toroidal type continuously variable transmission as described above, due to looseness due to dimensional tolerance between respective parts, and in the double cavity type having two sets of power rollers, the shaft is twisted or the like. , When the transmission torque of the continuously variable transmission changes, the timing of the change of the torque transmitted by each power roller is deviated, or the friction that acts when shifting the individual power rollers is slightly different. In some cases, the transmission torques of the respective power rollers are different from each other, and the difference in the transmission torques and the difference in the shift start timing may be applied to the power rollers and the trunnions as a disturbance.

However, the shift control valve 4 of the above-mentioned conventional example.
In 1 ', for example, the pressure oil stored in one valve chamber 44A is supplied to a plurality of hydraulic cylinders 1A, 1B via an oil passage 90H.
In this case, the hydraulic cylinders 1A and 1B are always connected via the oil passages 90H and 90L because they are supplied to the oil chambers 33B and 34B. The force corresponding to the disturbance also acts on the other hydraulic cylinder, causing the trunnion and the power roller to vibrate in the axial direction as shown in FIG. 10, and this vibration causes the power roller to which the disturbance is input and the power of the other side. Since the rollers vibrate in the directions in which the gear ratios are opposite to each other, there is a problem that the maximum value of the transmission torque of the toroidal type continuously variable transmission is reduced, or the drivability is reduced due to the vibration of the transmission torque. In the upshift when the accelerator pedal is released after the end of acceleration, the transmission torque of the continuously variable transmission changes from positive to negative, so there is a problem that the above vibration is likely to occur. Was Tsu.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic control device for a toroidal type continuously variable transmission which can suppress vibration even when disturbance is applied.

[0012]

According to a first aspect of the present invention, a toroidal groove is formed on surfaces facing each other, and an input disk and an output disk are coaxially arranged, and the input disk and the output disk. A plurality of friction rollers sandwiched between the surfaces facing each other and tiltable, and a rotary shaft that is substantially orthogonal to the axes of the input and output disks, and eccentric shafts that respectively support the friction rollers are provided. Roller support members rotatable about the axis of the rotary shaft and displaceable in the axial direction, hydraulic cylinders respectively driving the roller support members in the axial direction of the rotary shaft, and a gear shift for controlling hydraulic pressure to the hydraulic cylinders. The control valve and the actual gear ratio are fed back by transmitting the rotation amount of the roller support member to the gear shift control valve so that the gear ratio between the input disc and the output disc reaches a predetermined target value. In the hydraulic control device for the toroidal type continuously variable transmission, the feedback means is disposed on one of the roller support members and is supplied from the shift control valve to each hydraulic cylinder. The hydraulic pressure is a first oil passage that connects the hydraulic cylinder of the roller support member having the feedback means to the speed change control valve, and a second oil passage that connects the hydraulic cylinder of the other roller support member to the speed change control valve. Supply and discharge of hydraulic oil are performed independently through the oil passages.

In a second aspect of the invention, a toroidal groove is formed on the surfaces facing each other, and an input disk and an output disk coaxially arranged, and the facing surface of the input disk and the output disk. A plurality of friction rollers that are sandwiched between and tiltable, and a rotary shaft that is substantially orthogonal to the shafts of the input and output disks are formed, and eccentric shafts that respectively support the friction rollers are provided. Roller support members that are rotatable around and axially displaceable, hydraulic cylinders that drive these roller support members in the axial direction of the rotary shaft, and a shift control valve that controls the hydraulic pressure to the hydraulic cylinders. A feedback circuit that transmits the rotation amount of the roller support member to the shift control valve so that the gear ratio between the input disc and the output disc reaches a predetermined target value and feeds back the actual gear ratio. In a hydraulic control device for a toroidal-type continuously variable transmission including a drive-back means, the shift control valve includes a plurality of valve chambers that communicate with the oil chambers of the hydraulic cylinders, and the valve chambers are formed independently of each other. It

In a third aspect of the present invention, a toroidal groove is formed on the surfaces facing each other, and an input disk and an output disk coaxially arranged, and the facing surface of the input disk and the output disk. A plurality of friction rollers that are sandwiched between and tiltable, and a rotary shaft that is substantially orthogonal to the shafts of the input and output disks are formed, and eccentric shafts that respectively support the friction rollers are provided, and the shaft of the rotary shaft is provided. Roller support members that are rotatable around and axially displaceable, hydraulic cylinders that drive these roller support members in the axial direction of the rotary shaft, and a shift control valve that controls the hydraulic pressure to the hydraulic cylinders. A feed bar for transmitting the rotation amount of the roller support member to the shift control valve and feeding back the actual gear ratio so that the gear ratio between the input disc and the output disc becomes a target value. In the hydraulic control system of the toroidal type continuously variable transmission and a click means, said feedback means is arranged to one of the roller supporting member,
A pair of oil passages that connect the first oil chamber and the second oil chamber defined by the hydraulic cylinder of the roller supporting member having the feedback means to the shift control valve, and a differential pressure between the pair of oil passages. Accordingly, the differential pressure responsive means for driving the hydraulic cylinder of the other roller supporting member is provided.

The fourth invention is the first to third inventions.
In any one of the inventions, the shift control valve includes a spool and a sleeve capable of relative displacement, one of the spool and the sleeve is driven by the feedback means, and the other is driven by an actuator.

Further, in a fifth aspect based on the fourth aspect, one of the spool and the sleeve is provided with a flow rate characteristic adjusting means for setting a flow rate characteristic at an initial stage of valve opening, and the flow rate characteristic adjusting means. The spool or sleeve is provided with rotation preventing means for preventing rotation around the axis.

In a sixth aspect based on the third aspect, the differential pressure responsive means includes a second spool displaceable in the axial direction according to the differential pressure between the pair of oil passages, and the second spool. (2) An oil chamber for supplying and discharging hydraulic oil to and from a hydraulic cylinder of a roller supporting member having no feedback means according to displacement of the spool.

[0018]

Therefore, according to the first aspect of the present invention, the plurality of friction rollers sandwiched between the input disk and the output disk are tilted by the hydraulic cylinder that responds to the hydraulic pressure from the shift control valve to drive the roller support member in the axial direction. Rotation (displacement of the roller support member around the rotation axis) is performed to change the speed, and the feedback means provided in one of the plurality of roller support members controls the hydraulic pressure supplied from the speed change control valve to the hydraulic cylinder. The actual gear ratio corresponding to the tilt amount of the friction roller is adjusted to match the target gear ratio. The hydraulic oil of the roller support member provided with the feedback means supplies and discharges the hydraulic oil of the shift control valve and the hydraulic cylinder via the first oil passage, while the hydraulic cylinder of the other roller support member having no feedback means is provided. Does independently via the second oil passage,
For example, when a disturbance is applied to the friction roller of the roller supporting member having no feedback means, the hydraulic pressure fluctuation according to the disturbance is transmitted from the hydraulic cylinder to the shift control valve, but the first oil passage and the second oil passage are independent. Since the oil pressure fluctuation of the second oil passage is not transmitted to the first oil passage, it is possible to prevent the feedback means from operating due to the oil pressure fluctuation caused by the disturbance, and the disturbance causes the roller support member and the friction. It is possible to prevent the rollers from vibrating.

Further, in the second aspect of the invention, since the shift control valve includes a plurality of independent valve chambers that communicate with the oil chambers of the hydraulic cylinders, for example, the friction roller of the roller supporting member having no feedback means is disturbed. When the oil pressure is applied, the hydraulic pressure fluctuation according to the disturbance is transmitted from the oil chamber of the hydraulic cylinder to the valve chamber of the speed change control valve, but the valve chambers communicating with the oil chambers are independent of each other, and are caused by the disturbance. Vibration of the roller support member and the friction roller can be prevented.

According to a third aspect of the invention, the hydraulic cylinder of the roller supporting member provided with the feedback means supplies and discharges the hydraulic oil from the speed change control valve to the first and second oil chambers via a pair of oil passages. The gear ratio is changed by using the hydraulic cylinder of the other roller supporting member that does not have the feedback means, because the hydraulic oil is supplied and discharged by the differential pressure responsive means that responds to the differential pressure between the pair of oil passages. When disturbance is applied to the friction roller of the roller support member without feedback means,
The hydraulic pressure fluctuation according to the disturbance is transmitted to the differential pressure responsive means,
The differential pressure responsive means can prevent transmission to the hydraulic cylinder provided with the feedback means, and can prevent vibration of the roller support member and the friction roller due to disturbance.

According to a fourth aspect of the present invention, the speed change control valve includes a spool and a sleeve capable of relative displacement, one of the spool and the sleeve is driven by the feedback means, and the other is driven by an actuator. One of the sleeve and the spool is driven according to the target gear ratio, and the other is driven by the feedback means according to the actual gear ratio to adjust the hydraulic pressure supplied by the gear shift control valve to set the actual gear ratio set by the friction roller. Match the target gear ratio.

Further, in the fifth aspect of the invention, the spool of the speed change control valve or the spool is provided with the flow rate characteristic adjusting means for setting the flow rate characteristic in the initial stage of valve opening and the rotation preventing means.
By maintaining the relative relationship between the valve chamber of the shift control valve and the spool or the sleeve, the flow rate characteristic at the initial stage of valve opening can be adjusted accurately.

According to a sixth aspect of the present invention, the differential pressure responsive means synchronizes the hydraulic cylinder of the roller supporting member having no feedback means by displacing the spool in the axial direction according to the differential pressure between the pair of oil passages. Which can be driven dynamically, and the other hydraulic cylinder that is equipped with the feedback means and the other hydraulic cylinder are reliably separated to prevent vibration due to disturbance,
All hydraulic cylinders can be driven synchronously.

[0024]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a hydraulic control device for a single-cavity toroidal type continuously variable transmission. The continuously variable transmission is constructed in the same manner as in FIGS. No. and the duplicate description is omitted.

In FIG. 1, trunnions 4 and 5 as roller supporting members that axially support the power rollers 2 and 3 via eccentric shafts 6 and 6 are housed in a housing 10, and the trunnions 4 and 5 rotate. Tilt axis 23 as axis
Radial bearings 25 and 26 are provided above and below the power rollers 2 and 3 so as to be rotatable around a and 23b (around the Y-axis), and the radial bearings 25 above and below the trunnions 4 and 5 are provided. , 26 are tie rods 2
7, 28 are connected to each other.

The tie rods 27 and 28 are swingably supported by the housing 10 via joints 29 and 30 provided in the center, and the trunnions 4 and 5 can move up and down in the Y axis direction and rotate around the Y axis in opposite directions. Become mobile. The rotation angle around the Y axis is indicated by φ.

On the other hand, the hydraulic cylinder 1 of the trunnions 4 and 5
The shift control valve 41 for controlling the hydraulic pressure to A and B is a sleeve 4 having two valve chambers shown in FIG. 9 of the conventional example.
Instead of 2 ', as will be described later, hydraulic cylinders 1A, 1B
The sleeve 42 is provided with an independent valve chamber that communicates with each oil chamber.

First, in the housing of the shift control valve 41,
Oil chamber 33A of hydraulic cylinder 1A for driving trunnion 4
And a port 47A communicating with the oil chamber 7B via the oil passage 7L and a port 48A communicating with the oil chamber 33B via the oil passage 7H are formed in the upper half of the figure, while the trunnion 5 is formed in the lower half of the housing. Oil chamber 3 of hydraulic cylinder 1B for driving
4A and a port 47B that communicates with the oil passage 8L, and a port 48B that also communicates with the oil chamber 34B through the oil passage 8H.
And a line pressure port communicating with the hydraulic pressure supply means 40 such as a hydraulic pump is formed between the ports 47B and 48B, and the oil passages 7H and 7L form the first oil passage, and the oil passages 8H and 8L form the second oil passage. Form independently.

Tank ports communicating with the tank are formed at both ends (not shown) of the housing.

A sleeve 42 and a spool 43, which are relatively displaceable in the axial direction, are accommodated in the housing, one of which is driven by a shift controller 52 via an actuator 50 such as a step motor, and the other is the lower end of the trunnion 4. The displacement (actual speed ratio) of the rod 24 protruding from the position is fed back. Here, the case where the sleeve 42 is driven by the actuator 50 and the spool 43 is driven by the trunnion 4 via the precess cam 35 and the link 36 as the feedback means is shown.

The sleeve 42 formed of a tubular member has
When the actuator 50 is in the neutral position (position where the hydraulic pressure of the hydraulic cylinders 1A and 1B is maintained so as to maintain a predetermined gear ratio), the valve chambers 44A and 44B facing the ports 47A and 48A are penetrated in the upper half in the figure. While forming the valve chambers 45A, 45 facing the ports 47B, 48B, respectively.
B is penetratingly formed in the lower half of the figure. A valve chamber 46 that can communicate with the line pressure port 9 is provided between the valve chambers 45A and 45B.
Are formed through.

These valve chambers 44A, 44B and 45A, 4
As shown in FIG. 2, 5B is formed in accordance with the arrangement position of the ports 47A to 48B. For example, as shown in FIG. 2, the valve chambers 44A and 45A are formed independently of each other. Although not formed, the valve chambers 44B and 45B are also independently formed at the opposing positions.

The spool 43 accommodated in the inner circumference of the sleeve 42 has valve chambers 44A, 45A facing each other.
And a pair of land portions 43A and 43B capable of sealing 44B and 45B, respectively.

As in the above-mentioned conventional example, the transmission controller 52 determines the engine speed N as the operating condition of the vehicle.
e, input shaft speed Ni, vehicle speed VSP, throttle opening T
VO and the like are read from a sensor (not shown), a target gear ratio is determined from a preset map, etc., and the sleeve 42 is driven via the actuator 50 to an axial position corresponding to the target gear ratio.

With the above construction, the operation will be described.

The sleeve 42 is driven according to the target gear ratio determined by the gear shift controller 52, and the respective oil passages 7H, 7H.
It is possible to reliably supply and discharge the hydraulic oil to and from L, 8H, and 8L. For example, when the driver depresses the accelerator pedal to accelerate the vehicle, the shift controller 52 determines the predetermined driving state from the read driving state. The target gear ratio is set to the Low side according to the map or the like, the actuator 50 drives the sleeve 42 to the right side in the drawing, and a gap is formed between the land portion 43A of the spool 43 and the sleeve 42, and the valve chamber 44A, 45A communicates with the valve chamber 46 to guide the pressure oil from the line pressure port 9 to the oil passages 7L and 8L, while the spool 4
The space between the land portion 43B of FIG.
4B and 45B communicate with the tank port on the right side in the drawing to discharge the pressure oil in the oil passages 7H and 8H to the tank.

Therefore, the oil chamber 3 of the hydraulic cylinders 1A, 1B
The pressure oil from the line pressure port 9 is supplied to 3A and 34A, while the pressure oil in the oil chambers 33B and 34B is discharged, and the trunnion 4 moves upward in the drawing in accordance with the differential pressure between the oil chambers 33A and 33B. Since the trunnion 5 is displaced downward in the drawing according to the pressure difference between the oil chambers 34A and 34B, the rotary shafts of the power rollers 2 and 3 are displaced from the neutral line 37.

Then, as shown in FIG. 3, a tilt component is generated in the traction force at each contact point between the input disk 12, the output disk 13 and the power rollers 2, 3 and the power rollers 2, 3 have a gear ratio. Tilt axis 23 on the Low side
Since the input side contact radius Rin of the input disc 12, the output disc 13 and the power rollers 2, 3 is decreased because of the tilting around a and 23b, the output side contact radius Rout is increased to shift to the low side (tilt). Start).

Then, according to the tilt of the power roller 2,
The rod 24 and the recess cam 35 also rotate around the tilt axis 23a, the link 36 swings along the inclined surface of the recess cam 35, and the spool 43 is driven rightward in the drawing in accordance with the tilt. At this time, when the spool 43 catches up with the sleeve 42, both of them continue to be displaced rightward in the figure at the same speed.

When the actuator 50 drives the sleeve 42 to a predetermined position corresponding to the target gear ratio, it stops, but the spool 43 displaced at the same speed as the sleeve 42 overtakes the sleeve 42, so that the land portions 43A, 43B.
And each of the valve chambers 44A to 45B form a gap in the direction opposite to that at the start of the gear shift, and the pressure oil is discharged from the valve chambers 44A and 45A to the tank port on the left side (not shown), so that the hydraulic cylinder 1
The oil pressure in the oil chambers 33A and 34A of A and 1B decreases, while
Pressure oil of the line pressure port 9 is supplied from the valve chambers 44B and 45B, and the oil chambers 33B and 34 of the hydraulic cylinders 1A and 1B are supplied.
The hydraulic pressure of B rises.

As a result, the trunnions 4 and 5 are displaced in the opposite direction to the start of the gear shift according to the pressure difference between the oil chambers, and the power roller 2 is displaced downward and the power roller 3 is displaced upward in FIG. Then, the rotary shaft is again aligned with the neutral line 37, and the gear shift is completed.

In this way, each valve chamber 44A of the sleeve 42
Precess cam 35 while making each 45B independent
The mechanical feedback of the actual gear ratio by means of the link 36 and the link 36 can be performed in the same manner as in the conventional example.

By the way, when the above-mentioned conventional disturbance is applied to the trunnion 5 which does not have the recess cam 35 at the time of shifting as described above, for example, a force is applied to the trunnion 5 in the downward direction of FIG. , Because the oil pressure in the oil chamber 34B of the hydraulic cylinder 1B rises, the oil passage 8H and the valve chamber 45B
Of the trunnion 4 of the other side since the oil passage 8L and the valve chamber 44B are also depressurized in accordance with the depressurization of the oil chamber 34, but the valve chambers 44B and 45B are sealed by the land portion 43B of the spool 43. Since it is possible to prevent the displacement of one trunnion in the axial direction according to the disturbance, the other trunnion is prevented from being displaced, unlike the conventional example, without changing the hydraulic pressure in the valve chambers 44A and 44B. It is possible to prevent vibration of the trunnions 4 and 5 and the power rollers 2 and 3 as in the conventional example.

For example, in the upshift when the accelerator pedal is released after the end of acceleration, the transmission torque changes from positive to negative, so that, as shown in FIG. 10 of the conventional example, the vibration of the trunnion and the power roller due to the disturbance is generated. Although it tends to occur, the hydraulic cylinders 1A, 1A, 1
By making the oil chambers 33A to 34B of B independent from each other, vibration of the trunnion and the power roller can be suppressed as shown in FIG. 4, and the decrease in transmission torque and the decrease in drivability as in the conventional example can be prevented. Thus, the stability of the toroidal type continuously variable transmission can be improved.

FIG. 5 shows a second embodiment of the spool 4
The notches 62 and 63 are formed in the vicinity of the ends of the land portions 43A and 43B formed in No. 3 as notches for adjusting the flow rate characteristics in the initial stage of valve opening, and the rotation preventing means of the spool 43 serves as a base of the spool 43. The pin 61 is provided so as to project from the end toward the housing side, and the groove 60 for guiding the pin 61 only in the axial direction is formed on the housing side. The other configurations are the same as those in the first embodiment.

By restricting the rotation of the spool 43 by the pin 61, the notches 62 and 63 are respectively formed in the valve chamber 44.
The relative positional relationship with A and 45A can be maintained at all times, and the flow rate characteristics at the initial stage of valve opening can be maintained at a predetermined design value.

Further, the sizes of the notches 62 and 63 can be changed according to the flow rate of the hydraulic oil supplied from the valve chamber. For example, two sets of input / output discs (cavities) and two sets are provided.
When the speed change control valve 41 of FIG. 5 is applied to a double cavity type toroidal type continuously variable transmission (not shown) including a set (four in total) of power rollers, the port 47A facing the valve chamber 44A has a precess cam. Port 4 of the valve chamber 45A, which communicates with the oil chamber of the hydraulic cylinder on the side of which the valve 35 is provided.
7B communicates with the oil chambers that drive the other three power rollers that are not provided with precess cams, and in order to equalize the strokes of the four hydraulic cylinders, the notch 62 and the notch 63 have different flow rates of hydraulic oil. different.

Therefore, as shown in FIGS. 5A and 5B, the cutout areas of the notches 62 and 63 are changed to secure a flow rate for obtaining a uniform stroke.

Generally, the flow rate characteristic of the orifice is
The flow rate Q can be approximated by the following equation, where Q is the flow rate, C is the orifice flow coefficient, A is the opening area, ΔP is the differential pressure across the orifice, and ρ is the specific gravity of the hydraulic oil.

[0051]

[Equation 1]

Since this equation shows that the flow rate Q is proportional to the opening area A, in the above-mentioned double-cavity type continuously variable transmission, the notch 62 on the precess cam side has three other hydraulic cylinders. It suffices to set the area of the notch 63 for supplying hydraulic oil to 3 times.

The oil chambers of the three hydraulic cylinders for driving the trunnion without the precess cam communicate with the ports 47B and 48B in FIG. 5, respectively, and drive the power roller of the cavity without the precess cam of the two power rollers. The oil chambers of the hydraulic cylinders that communicate with each other communicate with each other through the ports 47B and 48B. However, even if the hydraulic cylinders in the same cavity communicate with each other, these oil chambers will not communicate with each other. When communicating with the oil chamber of the hydraulic cylinder, the vibration due to the disturbance as in the conventional example is unlikely to occur.

FIG. 6 shows a third embodiment of the present invention, in which the hydraulic cylinder 1 for driving the trunnion 4 having the recess cam 35 by using the shift control valve 41 'shown in FIG. 9 of the conventional example.
A oil chambers 33A, 33B and an oil chamber 34 of a hydraulic cylinder 1B for driving the trunnion 5 having no recess cam 35.
A hydraulic cylinder 1 is provided with a differential pressure control valve 70 as a differential pressure responsive means interposed in oil passages 90H and 90L communicating with A and 34B.
The oil chambers 33A33B of A and 1B and the oil chamber 34A34B are independent.

The shift control valve 41 'includes a pair of oil passages 90H and 9H.
By controlling the hydraulic pressures Phi1 and Plow1 of 0 L, the hydraulic cylinder 1A connected to the trunnion 4 having the recess cam 35 is driven, and the hydraulic cylinder 1B of the other trunnion 5 is driven by the hydraulic pressure from the differential pressure control valve 70. Phi2 and Plow
Driven based on 2.

The differential pressure control valve 70 is mainly composed of an axially displaceable spool 70A, and the spool 70A is constantly urged toward a neutral position by springs 71A and 71B provided at both ends.

Oil passages 90H and 90L communicating with the shift control valve 41 and the oil chambers 33A and 33B of the hydraulic cylinder 1A communicate with oil chambers 71A and 71B defined at both ends of the spool 70A. 71B oil pressure is spool 7
It acts on both end faces A1 and A2 of 0A.

A line pressure port 9'communicating with the hydraulic pressure supply means 40 is formed in the housing of the differential pressure control valve 70, and the hydraulic pressure from the line pressure port 9'corresponds to the displacement of the spool 70A. , 91L to the oil chambers 34A, 34B of the hydraulic cylinder 1B.

The oil pressure in the oil passages 91H and 91L is the oil pressure in the oil chambers 73A and 7A facing the lands at both ends of the spool 70A.
The oil pressure in the oil chambers 73A and 73B is also guided to 3B and acts on the end surfaces B1 and B2 of the lands at both ends of the spool 70A.

The areas of the land end faces B1 and B2 and the end faces A1 and A2 of the spool 70A are all set to be equal, and the hydraulic pressures Phi1 and Plow1 of the oil passages 90H and 90L supplied from the shift control valve 41 are set. Force corresponding to the differential pressure and oil passages 91H and 91L supplied from the differential pressure control valve 70
When the forces corresponding to the pressure difference between the hydraulic pressures Phi2 and Plow2 are balanced, in other words, since the areas of both ends of the spool 70A and the end surface of the land are all equal, the spool 70A stops at the neutral position when the pressure difference is equal. However, if they are not equal, the spool 70A is displaced to supply the oil pressure from the line pressure port 9'to the oil passage 91H or 91L, and the oil chambers 34A, 34A of the hydraulic cylinder 1B are adjusted so that the respective differential pressures become equal.
Adjust the supply pressures Plow2 and Phi2 to B. Therefore, the hydraulic cylinders 1A and 1B can drive the trunnions 4 and 5 with the same force as in the above embodiment, and the oil chambers 33A and 33B of the hydraulic cylinders 1A and 1B and the oil chamber 34A,
Since 34B is made independent by the differential pressure control valve 70, it is possible to prevent the vibration of the trunnions 4 and 5 due to the disturbance and stabilize the shifting operation of the toroidal type continuously variable transmission as in the above-described embodiment.

FIG. 7 shows a fourth embodiment, in which the transmission control valve 41 of the first embodiment is a double cavity type continuously variable transmission having two sets of input / output disks and four power rollers (not shown). The shift control valve 41A is provided with eight ports so as to control the above.

The sleeve 82 driven by the actuator 50 has four valve chambers 44A to 44D and 45A to 45D.
Are formed at positions facing each other, and further, the valve chamber 45
A valve chamber 4 is provided between A and 45B and between the valve chambers 45C and 45D.
6A and 46B are formed.

Ports 47A to 47D and 48A to 48D and line pressure ports 9A and 9B capable of communicating with these valve chambers are formed in the housing.

A precess cam 35 is provided on the inner circumference of the sleeve 81.
The spool 82 driven by the
Two land portions capable of sealing each valve chamber are formed on the second portion 2.

Ports 47A to 48D communicate with the upper and lower oil chambers of four hydraulic cylinders (not shown) for driving the four power rollers.
Is connected to an oil chamber (hereinafter, referred to as Phi side) that drives the power roller to the Hi side of the gear ratio among the two oil chambers of the hydraulic cylinder equipped with the recess cam. Similarly, the port 47B connects this power roller to the gear chamber of the gear ratio. It communicates with an oil chamber that is driven to the Low side (hereinafter referred to as the Plow side).

In addition, the other ports 47C, 47D and 4
8A to 48D communicate with oil chambers on the Phi and Plow sides of a hydraulic cylinder that drives a power roller having no precess cam, and independently control each oil chamber.

In this case, as in the above embodiment, since pressure oil is supplied from one valve chamber to one oil chamber, it is possible to prevent vibration from occurring due to disturbance applied to the power roller,
Further, it becomes easy to process and mold the flow rate characteristics of the hydraulic oil supplied to the respective oil chambers to be the same. Furthermore, since the sleeve 81 and the spool 82 are only extended in the axial direction, the shift control valve 41A is Since it can be formed in a plane, for example, it is possible to prevent the height of the continuously variable transmission from increasing and to improve the mountability on the vehicle body.

[0068]

As described above, according to the first aspect of the present invention, the hydraulic oil of the roller support member having the feedback means supplies and discharges the hydraulic oil to and from the shift control valve and the hydraulic cylinder via the first oil passage. On the other hand, since the hydraulic cylinder of the other roller support member having no feedback means performs the operation independently via the second oil passage, for example, when a disturbance is applied to the friction roller of the roller support member having no feedback means,
Although the hydraulic pressure fluctuation according to the disturbance is transmitted from the hydraulic cylinder to the shift control valve, the hydraulic pressure fluctuation of the second oil passage is transmitted to the first oil passage because the first oil passage and the second oil passage are independent. Therefore, the feedback means can be prevented from operating due to the fluctuation in hydraulic pressure due to the disturbance, and the vibration of the roller support member and the friction roller due to the disturbance as in the conventional example can be prevented, and the transmission as in the conventional example can be prevented. It is possible to improve the stability of the toroidal type continuously variable transmission by preventing a decrease in torque and a decrease in drivability.

Further, in the second aspect of the invention, since the shift control valve has a plurality of independent valve chambers that communicate with the oil chambers of the hydraulic cylinders, for example, the friction roller of the roller support member having no feedback means is disturbed. When the oil pressure is applied, the hydraulic pressure fluctuation according to the disturbance is transmitted from the oil chamber of the hydraulic cylinder to the valve chamber of the speed change control valve, but the valve chambers communicating with the oil chambers are independent of each other, and are caused by the disturbance. It is possible to prevent the vibration of the roller support member and the friction roller, prevent a decrease in transmission torque and a decrease in drivability as in the conventional example, and improve the stability of the toroidal continuously variable transmission.

According to a third aspect of the invention, the hydraulic cylinder of the roller supporting member provided with the feedback means supplies and discharges the hydraulic oil from the speed change control valve to the first and second oil chambers through a pair of oil passages. The gear ratio is changed by using the hydraulic cylinder of the other roller supporting member that does not have the feedback means, because the hydraulic oil is supplied and discharged by the differential pressure responsive means that responds to the differential pressure between the pair of oil passages. When disturbance is applied to the friction roller of the roller support member without feedback means,
The hydraulic pressure fluctuation according to the disturbance is transmitted to the differential pressure responsive means,
The differential pressure responsive means can prevent transmission to the hydraulic cylinder on the side provided with the feedback means, can prevent vibration of the roller support member and the friction roller due to disturbance, and can reduce the transmission torque and drive as in the conventional example. It is possible to improve stability of the toroidal-type continuously variable transmission by preventing deterioration of performance.

According to a fourth aspect of the present invention, the speed change control valve includes a spool and a sleeve that are capable of relative displacement, one of the spool and the sleeve is driven by the feedback means, and the other is driven by an actuator. One of the sleeve and the spool is driven according to the target gear ratio, and the other is driven by the feedback means according to the actual gear ratio to adjust the hydraulic pressure supplied by the gear shift control valve to set the actual gear ratio set by the friction roller. Accurate gear shift operation can be performed by matching the target gear ratio.

According to the fifth aspect of the invention, the spool of the speed change control valve or the spool is provided with the flow rate characteristic adjusting means for setting the flow rate characteristic at the initial stage of valve opening and the rotation preventing means.
By maintaining the relative relationship between the valve chamber of the shift control valve and the spool or the sleeve, the flow rate characteristic at the initial stage of valve opening can be accurately adjusted, and stable shift control can be performed.

According to a sixth aspect of the invention, the differential pressure responsive means synchronizes the hydraulic cylinder of the roller supporting member having no feedback means by displacing the spool in the axial direction according to the differential pressure between the pair of oil passages. Which can be driven dynamically, and the other hydraulic cylinder that is equipped with the feedback means and the other hydraulic cylinder are reliably separated to prevent vibration due to disturbance,
All hydraulic cylinders can be driven synchronously,
It becomes possible to improve the stability of the toroidal-type continuously variable transmission by preventing a decrease in transmission torque and a decrease in drivability as in the conventional example.

[Brief description of drawings]

FIG. 1 is a schematic view of a toroidal type continuously variable transmission and a shift control valve according to an embodiment of the present invention and a hydraulic control device.

FIG. 2 is a perspective view of an essential part of the sleeve.

FIG. 3 is a plan view of the input / output disk, which is an explanatory view showing the operation.

FIG. 4 is a graph showing the relationship between the displacement of the trunnion in the Y-axis direction and the tilt angle φ and time.

FIG. 5 is a sectional view of the shift control valve according to the second embodiment,
(A) is an enlarged view of the spool with a notch, (B)
Shows an enlarged view of the spool having the second notch, respectively.

FIG. 6 is a schematic cross-sectional view of a toroidal type continuously variable transmission, a shift control valve and a differential pressure control valve, and a hydraulic control device according to a third embodiment.

FIG. 7 is a sectional view of a shift control valve according to a fourth embodiment.

FIG. 8 is a vertical sectional view of a single-cavity toroidal type continuously variable transmission showing a conventional example.

FIG. 9 is a schematic view of a cross section of a toroidal type continuously variable transmission and a shift control valve, and a hydraulic control device.

FIG. 10 is a graph showing the relationship between displacement and tilt angle φ of the trunnion in the Y-axis direction and time.

[Explanation of symbols]

 1A, 1B Hydraulic cylinder 2, 3 Power roller 4, 5 Trunnion 6 Eccentric shaft 7H, 7L Oil passage 8H, 8L Oil passage 9 Line pressure port 10 Casing 11 Input shaft 12 Input disk 13 Output disk 23a, 23b Tilting shaft 24 Rod 27, 28 Tie rod 29, 30 Joint 31, 32 Piston 33A, 33B Oil chamber 34A, 34B Oil chamber 35 Precess cam 36 Link 37 Neutral line 40 Hydraulic pressure supply means 41 Shift control valve 42 Sleeve 43 Spool 44A, 44B Valve chamber 45A, 45B valve Chamber 46 Valve chamber 47, 48 port 47A, 47B, 48A, 48B port 50 Actuator 52 Speed change controller 60 Groove 61 Pin 62, 63 Notch 70 Differential pressure control valve 71A, 71B Spring 72A, 72B Oil chamber 73A, 73B Oil chamber 81 Sleeve 82 spool

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuya Kobayashi 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (6)

[Claims] 1. A toroidal groove is formed on the surfaces facing each other, and is tilted by being sandwiched between the input disk and the output disk arranged coaxially and the facing surfaces of the input disk and the output disk. Flexible friction rollers,
A roller support that is rotatable about the axis of the rotary shaft and is axially displaceable by forming a rotary shaft that is substantially orthogonal to the shafts of the input and output disks and providing eccentric shafts that respectively support the friction rollers. Members, hydraulic cylinders that drive these roller support members in the axial direction of the rotary shaft, a shift control valve that controls the hydraulic pressure to the hydraulic cylinders, and a gear ratio between the input disc and the output disc that has a predetermined target value. In the hydraulic control device of the toroidal type continuously variable transmission, the feedback control means includes a feedback means for transmitting the rotation amount of the roller support member to the shift control valve to feed back the actual gear ratio. The hydraulic pressure provided to one of the supporting members and supplied from the shift control valve to each hydraulic cylinder is provided by the feedback means. Of the hydraulic oil through the first oil passage that connects the hydraulic cylinder of the roller support member and the speed change control valve, and the second oil passage that connects the hydraulic cylinder of the other roller support member and the speed change control valve. A hydraulic control device for a toroidal type continuously variable transmission, which is characterized in that supply and discharge are performed independently. 2. A toroidal groove is formed on the surfaces facing each other, and the input disk and the output disk arranged coaxially are sandwiched between the facing surfaces of the input disk and the output disk and tilted. Flexible friction rollers,
A roller support that is rotatable about the axis of the rotary shaft and is axially displaceable by forming a rotary shaft that is substantially orthogonal to the shafts of the input and output disks and providing eccentric shafts that respectively support the friction rollers. Members, hydraulic cylinders that drive these roller support members in the axial direction of the rotary shaft, a shift control valve that controls the hydraulic pressure to the hydraulic cylinders, and a gear ratio between the input disc and the output disc that has a predetermined target value. In the hydraulic control device for the toroidal type continuously variable transmission, the feedback control means for transmitting the rotation amount of the roller support member to the shift control valve to feed back the actual gear ratio so that The oil of the toroidal type continuously variable transmission is characterized in that it has a plurality of valve chambers that communicate with the oil chambers of the cylinders, and that each valve chamber is formed independently. The control device. 3. A toroidal groove is formed on the surfaces facing each other, and is tilted by being sandwiched between the input disk and the output disk arranged coaxially and the facing surfaces of the input disk and the output disk. Flexible friction rollers,
A roller support that is rotatable about the axis of the rotary shaft and is axially displaceable by forming a rotary shaft that is substantially orthogonal to the shafts of the input and output disks and providing eccentric shafts that respectively support the friction rollers. Members, hydraulic cylinders for respectively driving these roller support members in the axial direction of the rotary shaft, a shift control valve for controlling hydraulic pressure to the hydraulic cylinders, and a gear ratio of the input disc and the output disc to be a target value. In the hydraulic control device for the toroidal type continuously variable transmission, the feedback control means includes a feedback means for transmitting the rotation amount of the roller support member to the shift control valve and feeding back the actual gear ratio. One of the first oil chamber and the first oil chamber defined in the hydraulic cylinder of the roller supporting member provided with the feedback means. A pair of oil passages communicating the oil chamber and the shift control valve, and a differential pressure responsive means for driving a hydraulic cylinder of another roller support member in accordance with the differential pressure of the pair of oil passages. Hydraulic control device for toroidal type continuously variable transmission. 4. The shift control valve comprises a spool and a sleeve capable of relative displacement, one of the spool and the sleeve being driven by the feedback means and the other being driven by an actuator. The hydraulic control device for a toroidal type continuously variable transmission according to claim 3. 5. One of the spool or the sleeve,
The flow rate characteristic adjusting means for setting the flow rate characteristic at the initial stage of valve opening, and the spool or sleeve provided with the flow rate characteristic adjusting means are provided with rotation preventing means for preventing rotation around the axis. A hydraulic control device for the toroidal type continuously variable transmission described. 6. The differential pressure responsive means has a second spool that is axially displaceable in accordance with the differential pressure between the pair of oil passages, and a roller that does not have feedback means in response to the displacement of the second spool. The hydraulic control device for a toroidal type continuously variable transmission according to claim 3, further comprising: an oil chamber that supplies and discharges hydraulic oil to and from a hydraulic cylinder of the support member.