JPH0772586B2 - Control device for friction wheel type continuously variable transmission - Google Patents

Description

The present invention relates to a control device for a friction wheel type continuously variable transmission.

(B) Conventional technology As a conventional friction wheel type continuously variable transmission, for example, Japanese Patent Laid-Open No. 63-13
There is one such as shown in Japanese Patent No. 0954. The friction wheel type continuously variable transmission shown in the drawing supports an input disc, an output disc, a friction roller that makes frictional contact with both discs, a friction roller that is rotatably supported, and is rotatable about a rotation shaft portion. Further, it has a roller support member movable in the axial direction of the rotary shaft portion, and a hydraulic cylinder for moving the roller support member in the axial direction of the rotary shaft portion. The gear ratio between the input disc and the output disc changes due to the rotation of the roller support member about the rotation shaft portion. In order to prevent the gear ratio from becoming larger than the maximum gear ratio and becoming smaller than the minimum gear ratio, a mechanical stopper for stopping the rotation of the roller support member is provided. That is, when the roller support member rotates about the rotation shaft portion in both directions by a predetermined angle, it comes into contact with the stopper and cannot rotate any further.

(C) Problems to be Solved by the Invention However, in the friction wheel type continuously variable transmission as described above,
For example, even if the roller support member rotates to the maximum gear ratio position and is stopped by the stopper, hydraulic pressure acts on the hydraulic cylinder to move the roller support member in the axial direction of the rotation shaft portion, so that one roller The supporting member moves upward in the axial direction of the rotating shaft portion, and the other roller supporting member moves downward, causing side slip at the contact portion between both discs and the friction roller, which reduces the transmitted rotational force. . The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention is a hydraulic pressure applying a force in the axial direction of the rotating shaft portion to the roller support member when the roller support member rotates to the maximum gear ratio position or the minimum gear ratio position. The above problem is solved by discharging the hydraulic pressure of the cylinder to stop the speed change operation. That is, the control apparatus for a friction wheel type continuously variable transmission according to the present invention includes an input disk, an output disk, a friction roller that makes frictional contact with both disks, a friction roller that is rotatably supported, and a rotary shaft portion as a center. A roller supporting member that is rotatable and movable in the rotating shaft axial direction, and a high-side oil chamber and a low-side oil chamber that move the roller supporting member to the high side and the low side in the rotating shaft axial direction, respectively. And a high-side discharge valve capable of discharging the hydraulic pressure of an oil passage to an oil passage communicating with the high-side oil chamber and the low-side oil chamber, respectively. A low-side discharge valve is provided.The high-side discharge valve and the low-side discharge valve are the high-side discharge valve when the roller support member rotates to the minimum gear ratio position due to the valve opening mechanism provided in the roller support member. The low side discharge valve is opened when the roller is opened and the roller support member is rotated to the maximum gear ratio position.In all other cases, the high side discharge valve and the low side discharge valve are kept closed. Is configured to be.

(E) Action For example, when the oil pressure in the low-side oil chamber rises and an axial force in a predetermined direction acts on the roller support member, the roller support member rotates about the rotation shaft portion to the low side. When the roller support member rotates to the maximum gear ratio position, the low side discharge valve is opened by the valve opening mechanism provided therein. As a result, the hydraulic pressure in the low-side oil chamber is discharged and the axial force acting on the roller support member is removed, so that the gear shifting operation is stopped. Therefore, when the roller supporting member reaches the maximum gear ratio position, the force for moving the roller supporting member in the axial direction disappears, and the above-described problem is prevented from occurring. The same applies when the gear is shifted to the maximum gear ratio side.

(F) Embodiment FIG. 3 shows the structure of the entire continuously variable transmission. A torque converter 12 is connected to a drive plate 10 that is integral with the output shaft of the engine. The torque converter 12 has a lock-up clutch 12a, and by controlling the hydraulic pressure in the lock-up oil chamber 12b, the pump impeller 12 on the input side is controlled.
It is possible to mechanically connect or disconnect the turbine runner 12d on the output side with c. Torque converter 12 cover 12e
An oil pump drive shaft 87 is connected to. The oil pump drive shaft 87 is connected to the oil pump 15 and can drive it. The oil pump 15 is arranged on the opposite side of the torque converter 12 with a friction wheel type continuously variable transmission mechanism 16 described later interposed therebetween. Further, the turbine runner 12d of the torque converter 12 is connected to the hollow input shaft 14. A friction wheel type continuously variable transmission mechanism 16 is connected to the input shaft 14. The friction wheel type continuously variable transmission 16 includes an input disc 18 and an output disc 20.
And a friction roller 22 that transmits the rotational force between them. The contact surfaces of the input disk 18 and the output disk 20 with the friction roller 22 are toroidal surfaces. Friction roller 22
The inclination of the shaft 24 can be adjusted by a mechanism described later shown in FIG. The input disk 18 is connected to the input shaft 14,
On the other hand, the output disk 20 is provided with a gear 26 so as to rotate integrally. The gear 26 is a gear 30 integrated with the idler shaft 28.
Are in mesh with each other. The idler shaft 28 is provided with a gear 32 that always rotates integrally with the idler shaft 28 and a gear 34 that is rotatably supported by the idler shaft 28. The gear 34 can be connected by a reverse clutch 36 so as to rotate integrally with the gear 30. The idler shaft 28 is rotated only in the forward direction by the one-way clutch 31 attached to the casing, and is not rotated in the reverse direction. This is to prevent the friction wheel type continuously variable transmission mechanism 16 from rotating in the direction opposite to the engine rotation direction due to the reverse driving force from the wheel side. A gear 40 is rotatably supported on another idler shaft 38 arranged in parallel with the idler shaft 28, and a gear 42
Are connected so that they always rotate together. The gear 40 can be connected by a forward clutch 44 so as to rotate integrally with the idler shaft 38. The gear 40 meshes with the gear 32. Gear 34 is in constant mesh with final gear 48. The final gear 48 has a pair of pinion gears 52 and 54 constituting a differential device 50 attached thereto. The pinion gears 52 and 54 and the pair of side gears 56 and 58 are meshed with each other, and the side gears 56 and 58 respectively output. The shaft is connected. With such a configuration, when the forward clutch 44 is engaged, the output shaft rotates in the forward direction, and when the reverse clutch 36 is engaged, the output shaft rotates in the backward direction. In addition, the friction roller of the friction wheel type continuously variable transmission 16
By controlling the contact state of the input disk 18 and the output disk 20 of 22, the gear ratio can be continuously changed.

FIG. 4 shows the friction wheel type continuously variable transmission mechanism 16 in detail. Input shaft
14 is rotatably supported by a casing 67 via a ball bearing 65 and a needle bearing 66. In addition,
A spacer 68 is provided between the input shaft 14 and the ball bearing 65. A disc spring 70 is provided between the spacer 68 and the loading nut 69 screwed onto the input shaft 14. As a result, the reaction force of the disc spring 70 acts so as to push the input shaft 14 rightward in the drawing. Loading nut
The tip of 69 is prevented from loosening by a pin 71 whose tip enters the groove 14a of the input shaft 14. A plurality of holes 69a for receiving the pins 71 are provided, and a plurality of grooves 14a for the input shaft 14 are also provided. By combining the two, it is possible to finely adjust the fixing position of the loading nut 69. Pin 71 is a screw
Secured by 72. An output disk 20 is rotatably supported on the input shaft 14 via a bearing 73. The output disk 20 is provided with output gears 26 so as to rotate integrally via the keys 74 arranged at two symmetrical positions. The gear 26 is supported by the casing 67 via a ball bearing 75. Further, an input disk 18 is provided on the input shaft 14 via a bearing 76 so as to be rotatable and axially movable. A cam flange 77 is provided on the back side of the input disk 18, that is, on the side opposite to the side facing the output disk 20. The cam flange 77 is splined with the input shaft 14 and the shoulder 78 of the input shaft 14 is provided.
This prevents movement to the left in FIG. A cam roller 79 is provided between the cam surfaces 18a and 77a of the input disk 18 and the cam flange 77 which face each other. The cam surfaces 18a and 77a and the cam roller 79 are shaped so that when the cam flange 77 and the input disk 18 rotate relative to each other, a force is generated to press the input disk 18 to the right in FIG. A friction roller 22 arranged in a toroidal groove formed by the surfaces of the input disk 18 and the output disk 20 facing each other is rotatably supported by a shaft 80 via a bearing 81. Further, the friction roller 22 is supported in the thrust direction by a ball bearing 82. The ball bearing 82 is supported by the roller support member 83. Friction roller 22, ball bearing
The roller support member 83 and the roller support member 82 are prevented from coming off by snap rings 84 and 85 provided at both ends of the shaft 80. Input shaft
The sleeve 86 is inserted into the inner diameter of 14 and snap ring
It has been prevented by 97. The diameter of the sleeve 86 is smaller than the inner diameter of the input shaft 14 except for both ends where the O-rings 96 and 95 are provided, respectively, and an oil passage 88 is formed by a clearance having an annular cross section therebetween. The input shaft 14 is provided with radial holes 94, 93, 92 and 91 communicating with the oil passage 88. In addition, the input shaft 14 has a hole in the casing 67.
A groove 101 and a hole 102 for receiving oil from 90 are provided. The groove 101 is sealed by a seal ring 103. The oil pump drive shaft 87 passes through the inner diameter of the sleeve 86. Inner diameter of sleeve 86 and oil pump drive shaft 87
An oil passage 89 for the lockup control hydraulic pressure of the torque converter 12 is formed by a clearance having an annular cross section with the outer diameter portion.

FIG. 5 shows a cross section taken along the line VV of FIG. The above-mentioned roller support member 83 is supported by the spherical bearings 110 and 112 on the upper and lower rotary shaft portions 83a and 83b so as to be rotatable and movable in the vertical direction. The spherical bearing 110 is held by a bearing support member 114, and the bearing support member 114 is supported by a link post 116 fixed to the casing 67. The spherical bearing 112 is also supported by the bearing support member 118, and the bearing support member 118 is supported by the link post 120 fixed to the upper control valve body 200. The upper control valve body 200 is attached to the casing 67. The roller support member 83 has an extension shaft portion 83c provided concentrically with the rotation shaft portion 83b. The extension shaft 8
3c is constituted by integrally fixing another member to the rotating shaft portion 83b. A piston 124 is provided on the outer circumference of the extension shaft portion 83c. The piston 124 is fitted inside a cylinder 126 provided in the upper control valve body 200. An oil chamber 128 is formed above the piston 124,
An oil chamber 130 is formed below 124. Oil chamber 130 on the right side of the figure
Is a hole 302 provided in the piston 124, a clearance 304 between the piston 124 and the small diameter portion of the extension shaft portion 83c, holes 306 and 308 provided in the roller support member 83 (note that the opening of the hole 306 is a ball 310).
(Closed by) is in communication with the opening of hole 308. There are also holes 3 in the race 312 of the bearing 82.
14 are provided. The roller support member 83 on the left side of the drawing has substantially the same oil passages (hole 302, clearance 304, holes 306 and 3).
08) is provided, except that the hole 302 communicates with the upper oil chamber 128. Also, holes 306 and 308 are connected by an annular groove 316. The left and right pistons 1
The holes 24 have the same shape except that the positions of the holes 302 are different. The upper end of the piston 124 is provided with a roller support member 83 via a spacer 132.
Is in contact with the bottom of the piston 124 and the spacer 134
Through the cam 136. The cam 136 has an extension shaft 83
It is attached by a bolt 138 so as to rotate integrally with c. The cam 136 is attached to the extension shaft portion 83c on the right side in FIG. 5, and is not provided on the extension shaft portion 83c on the left side. The left and right friction rollers 22, the roller support member 83, etc. are basically symmetrical with respect to other points. The portion 80a of the shaft 80 that supports the friction roller 22 and the portion 80b that is supported by the roller support member 83 are eccentric. The cam 136 has a beveled surface 140 with which the link 142 is in contact. As a result, the link 142 can be swung by rotating the cam 136. A lower control valve body 144 is attached to the lower surface of the upper control valve body 200 via a separate plate 202, and an oil pan 146 is casing to accommodate the valve body 144, the cam 136, and the like.
It is attached to 67. A shift control valve 150 is provided in the lower control valve body 144. Shift control valve
150 includes a drive rod 154 that is rotationally driven by a speed change motor 152, a sleeve 156, a spool 158 that is fitted in an inner diameter portion of the sleeve 156, and a spring 160 that presses the spool 158 rightward in the drawing. ing. Drive rod 1
54 has a threaded portion 154a at the tip, which is the sleeve.
It meshes with the female thread 156a of 156. The sleeve 156 has a groove 156b in the axial direction, and the pin 162 fixed to the lower control valve body 144 is inserted in the groove 156b. This allows the sleeve 156 to move axially without rotating. Spool 158
The end 158a on the side opposite to the side that contacts the spring 160 is pressed by the force of the spring 160 against the above-mentioned link 142. The spool 158 has lands 158a and 158b, by which the opening degree of the ports communicating with the oil passages 166 and 168 can be adjusted. The spool 158 is always at a predetermined axial position with respect to the sleeve 156 in the constant gear ratio state as shown in the figure, and supplies the hydraulic pressure of the same pressure to the oil passages 166 and 168. According to the above, the line pressure supplied from the oil passage 164 is distributed to the oil passages 166 and 168. The oil passage 168 is connected to an oil chamber 128 on the right side in the figure and an oil chamber 130 on the left side in the figure. The oil passage 166 is connected to the oil chamber 130 on the right side of the drawing and the oil chamber 128 on the left side of the drawing.

FIG. 2 shows a hydraulic control circuit. This hydraulic control circuit has a shift control valve 150, a line pressure regulating valve 502, a throttle valve 504, a manual valve 506, a lockup control valve 508, a constant pressure regulating valve 510 and a constant pressure regulating valve 512, which are shown in the drawing. Oil pump 15, high (small gear ratio) side oil chamber 516 (right side oil chamber 130 and left side oil chamber 128 in FIG. 5), low (high gear ratio) side oil. Chamber 518 (Fifth
Oil chamber 128 on the right side and oil chamber 130 on the left side in the figure), forward clutch 520, reverse clutch 522, apply side oil chamber 12f of torque converter 12, release side oil chamber 12b of torque converter 12, solenoid 528, oil Cooler 530, lubrication circuit 532
Etc. are also connected as shown.

The line pressure regulating valve 502 regulates the hydraulic pressure (line pressure) of the oil passage 534 to which the discharge pressure from the oil pump 514 is supplied. The throttle valve 504 regulates the hydraulic pressure (throttle pressure) corresponding to the force of the vacuum diaphragm 536 and outputs it to the oil passage 538. The shift control valve 150 adjusts the distribution of the hydraulic pressure to the high-side oil chamber 516 and the low-side oil chamber 518 as described above in accordance with the operation of the shift motor 152 to realize a predetermined gear ratio. Manual valve 506
Indicates the line pressure supplied from the oil passage 534 depending on the position of the select lever.
To switch between forward and reverse. The lockup control valve 508 adjusts the supply direction and the hydraulic pressure value of the hydraulic pressure to the apply side oil chamber 12f and the release side oil chamber 12b according to the hydraulic pressure obtained by the solenoid 528 whose duty ratio is controlled, and engages the lockup clutch 12a. -Control the release. Constant pressure regulator valve 510 regulates the constant pressure utilized by solenoid 528. The constant pressure regulating valve 512 regulates the hydraulic pressure supplied to the torque converter 12 so as not to exceed a constant value.

Next, the high-side discharge valve 580, the low-side discharge valve 582, and the arm 584 that is the valve opening mechanism shown in FIG. 1 will be described. The high side discharge valve 580 is composed of a cylinder 585, a ball 586 and a spring 587, and the ball 586 is pressed by the spring 587 toward the side that closes the opening of the cylinder 585. The cylinder 585 is connected to an oil passage 588 communicating with the high side oil chamber 516. The high-side oil chamber 516 and the high-side discharge valve 580 are provided on the same side divided by the orifice 589 provided in the oil passage 588. The low-side exhaust valve 582 is similar to the high-side exhaust valve 580 in that the cylinder 59
The cylinder 590 is connected to an oil passage 593 communicating with the low-side oil chamber 518. An orifice 594 is similarly provided in the oil passage 593. The arm 584 is attached so as to rotate integrally with the extension shaft portion 83c of the roller support member 83. The ball 586 of the high side discharge valve 580 described above is arranged at a position pushed by the arm 584 when the extension shaft portion 83c is rotated to the minimum gear ratio position, and the ball 5 of the low side discharge valve 582 is arranged.
Reference numeral 91 is arranged at a position which is pushed when the extension shaft portion 83c is rotated to the maximum gear ratio position.

Next, the operation of this embodiment will be described.

For example, when changing the gear ratio to the large side, the gear change motor 15
The shift control valve 150 is operated by 2 to increase the oil pressure in the low side oil chamber 518, and conversely decrease the oil pressure in the high side oil chamber 516. As a result, the roller support member 83 on the right side in FIG. 5 moves upward, and the roller support member 83 on the left side moves downward. Along with this, the direction of the tangential force acting on the friction roller 22 changes, so that the left and right roller support members 83 rotate in opposite directions about the rotation shaft portions 83a and 83b, respectively. As a result, the contact position radius of the friction roller 22 with the input disc 18 becomes smaller, and conversely the contact position radius of the output disc 20 becomes larger. That is, the gear ratio changes to the large side. The extension shaft portion 83c shown in FIG.
Since it is connected to rotate with the extension shaft part
83c rotates clockwise in FIG. Roller support member 8
When 3 rotates to the maximum gear ratio position, the arm 584 integral with the extension shaft portion 83c contacts the ball 591 of the low side discharge valve 582 and presses it against the force of the spring 592. Therefore, a clearance is formed between the inner diameter portion of the cylinder 590 and the ball 591, and the hydraulic pressure in the oil passage 593 is discharged. Since the oil passage 593 communicates with the low side oil chamber 518, the oil pressure in the low side oil chamber 518 is discharged. As a result, the vertical force acting on the roller support member 83 from the piston 124 does not act. At this time, the rotation of the roller support member 83 about the rotary shaft portions 83a and 83b is stopped by a mechanical stopper (not shown). Therefore, at the same time when the rotation of the roller support member 83 is stopped by the stopper, the vertical force acting on the roller support member 83 is also eliminated, and the gear shift is reliably stopped. That is, when the maximum gear ratio is reached, the force to shift gears to the higher gear ratio side no longer acts. As a result, the occurrence of side slip of the friction roller 22 is prevented.

Even when the gear ratio changes to the minimum gear ratio side, the oil pressure in the high-side oil chamber 516 is discharged through the oil passage 588 by the high-side discharge valve 580 by the same operation as described above. As described above, the force for shifting to the smaller gear ratio side is prevented from acting on the roller support member 83.

(G) Effect of the Invention As described above, according to the present invention, when the gear ratio is changed to the minimum gear ratio or the maximum gear ratio, the high side discharge valve or the low side discharge valve is operated by the rotation of the roller support member. Since the oil pressure in the low-side oil chamber or the high-side oil chamber is discharged, when the gear shift progresses to the minimum gear ratio or the maximum gear ratio, the force for further shifting does not act on the roller support member. It is possible to prevent the occurrence of side slip of the friction roller.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the entire hydraulic circuit, FIG. 3 is a sectional view of the entire continuously variable transmission, and FIG. 4 is an enlarged view of a friction wheel type continuously variable transmission mechanism. 5 is a sectional view taken along the line VV in FIG. 18 ... Input disc, 20 ... Output disc, 22 ... Friction roller, 83 ... Roller support member, 83a, 83b ... Rotating shaft portion, 83c ... Extension shaft portion, 516 ... High side oil chamber, 518 ... Low side oil chamber, 580 … High side discharge valve, 582… Low side discharge valve, 588… Oil passage,
593 ... oil passage, 584 ... arm.

Claims (1)

[Claims] 1. An input disk, an output disk, a friction roller that makes frictional contact with both disks, a friction roller that is rotatably supported, and that is rotatable about a rotary shaft portion and moves in the axial direction of the rotary shaft portion. Frictionless wheel type continuously variable transmission having a possible roller support member and a hydraulic cylinder having a high-side oil chamber and a low-side oil chamber for moving the roller support member to the high side and the low side in the axial direction of the rotary shaft, respectively. In the control device of the above, in the oil passages that respectively communicate with the high-side oil chamber and the low-side oil chamber,
A high-side discharge valve and a low-side discharge valve capable of discharging the oil pressure of the oil passage are provided. The high-side discharge valve and the low-side discharge valve are provided by a roller support member by a valve opening mechanism provided in the roller support member. Is rotated to the minimum gear ratio position, the high-side discharge valve is opened, and when the roller support member is rotated to the maximum gear ratio position, the low-side discharge valve is opened. A control device for a friction wheel type continuously variable transmission, wherein the valve and the low side discharge valve are configured to be held in a closed state.