JPH0819997B2 - Hydraulic control system for friction wheel type continuously variable transmission - Google Patents

Description

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

(B) Conventional technology As a conventional hydraulic control device for a friction wheel type continuously variable transmission,
For example, there is one disclosed in JP-A-61-11984.
This shows a friction wheel type continuously variable transmission equipped with an input disc, an output disc and a power roller. By moving a support body supporting the power roller in accordance with the hydraulic pressure acting on the hydraulic working chamber, By changing the contact state between the power roller and both discs, the gear ratio between the input disc and the output disc is continuously variable. The line pressure, which is the hydraulic pressure source of the hydraulic pressure supplied to the hydraulic pressure chamber, is set so as to increase substantially in proportion to the torque on the input disk side. That is, the hydraulic pressure in the hydraulic working chamber on the input disk side is fed back to the pressure increasing side port of the regulator valve.

(C) Problems to be Solved by the Invention However, in the conventional hydraulic control device for a friction wheel type continuously variable transmission as described above, when the engine brake state in which the torque is input from the output disc side, the hydraulic pressure is The line pressure needs to be set high with a margin because it may become low and the gear shift control may not be performed. For this reason, the load on the oil pump increases and the power loss increases. The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention solves the above problems by adjusting the line pressure according to the gear ratio.

That is, according to the present invention, an input disc, an output disc, a pair of friction rollers that frictionally contact both discs, and each friction roller are rotatably supported and are rotatable about a trunnion and movable in the trunnion axial direction. A roller support member, a hydraulic cylinder capable of moving each roller support member in the trunnion axial direction, a line pressure regulating valve for generating a line pressure according to an engine load, and a gear ratio according to an operating state. In a hydraulic control device for a friction wheel type continuously variable transmission having a shift control valve that controls the hydraulic pressure supplied to a hydraulic cylinder based on a line pressure, the rotational displacement of one trunnion is feedback-input to the shift control valve, and the other is The rotational displacement of the trunnion is input to the line pressure regulating valve together with the engine load so that the line pressure is regulated according to the gear ratio. It was.

(E) Action One trunnion is connected to the shift control valve, and the other trunnion is connected to the line pressure regulating valve. The throttle pressure corresponding to the engine load is also input to the line pressure regulating valve. Since the line pressure regulator regulates the line pressure according to the gear ratio and throttle pressure, the line pressure required by the hydraulic system is not only required during normal operation but also during engine braking when the torque transmission direction is reversed. Can be obtained. Further, since the two trunnions are connected to different valves, the layout is simplified and the valve case can be downsized.

(F) Embodiment FIG. 5 shows the structure of the entire continuously variable transmission. Torque converter 12 on drive plate 10 integrated with engine output shaft
Are connected. The torque converter 12 is provided with a lockup clutch 12a, and by controlling the hydraulic pressure of the apply side oil chamber 12f and the release side oil chamber 12b, the pump impeller 12c on the input side and the turbine runner 1 on the output side are controlled.
It is possible to mechanically connect or disconnect 2d. The oil pump drive shaft 87 is connected to the cover 12e of the torque converter 12. 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. A friction wheel type continuously variable transmission mechanism 16 is connected to the input shaft 14. The friction wheel type continuously variable transmission mechanism 16 has an input disk 18, an output disk 20, and a friction roller 22 for transmitting a 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. The inclination of the shaft 24 of the friction roller 22 can be adjusted by a mechanism described later shown in FIGS. 6 and 7. An input disk 18 is connected to the input shaft 14, while a gear 26 is provided on the output disk 20 so as to rotate integrally therewith. Gear 26
Meshes with a gear 30 integral with the idler shaft 28. 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 disposed in parallel with the idler shaft 28, and a gear 42 is connected so as to always rotate integrally. 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. The gear 34 meshes directly with the final gear 48. The gear 42 is always meshed with the final gear 48. A pair of pinion gears 52 and 54 constituting a differential device 50 are attached to the final gear 48. The pinion gears 52 and 54 and the pair of side gears 56 and 58 are meshed with each other to form the side gears 56 and 58.
The output shafts are connected to each other. 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. Further, by controlling the contact state of the friction roller 22 of the friction wheel type continuously variable transmission 16 with the input disk 18 and the output disk 20, the gear ratio can be continuously changed.

FIG. 6 shows the friction wheel type continuously variable transmission mechanism 16 in detail. The input shaft 14 is rotatably supported by a casing 67 via a ball bearing 65 and a needle bearing 66. A spacer is placed between the input shaft 14 and the ball bearing 65.
68 are provided. A disc spring 70 is provided between the spacer 68 and the loading nut 69 screwed onto the input shaft 14.
Is provided. As a result, the reaction force of the disc spring 70
14 acts to the right in the figure. The loading nut 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.
Fine adjustment of the fixed position of is possible. The pin 71 is prevented from coming off by a screw 72. The output disk 2 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 to the input shaft 14 and the shoulder portion of the input shaft 14
The movement to the left in FIG. 6 is prevented by 78.
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 arranged so that when the cam flange 77 and the input disk 18 rotate relative to each other, the input disk 18
Is shaped so as to generate a pressing force in the right direction 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. The friction roller 22, the ball bearing 82, and the roller support member 83 are prevented from coming off by snap rings 84 and 85 provided at both ends of the shaft 80. A sleeve 86 is inserted in the inner diameter portion of the input shaft 14 and is prevented from coming off by a snap ring 97. The input shaft 14 except for both ends of the sleeve 86 where the O-rings 96 and 95 are provided, respectively.
The inner diameter of the oil passage 88 is smaller than the inner diameter of the oil passage 88, and the oil passage 88 is formed by a clearance having an annular cross section between them. The input shaft 14 has
Radial holes 94, 93, 92 and 91 communicating with the oil passage 88 are provided. Further, the input shaft 14 is provided with a groove 101 and a hole 102 for receiving oil from the hole 90 of the casing 67. 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
An oil passage 89 for the lockup control hydraulic pressure of the torque converter 12 is formed by the annular clearance between the outer diameter portion 87 and the outer diameter portion.

FIG. 7 shows a cross section taken along the line VII-VII of FIG. The roller support member 83 is supported by spherical bearings 110 and 112 on the upper and lower trunnions 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 bare rig 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 trunnion 83b. The extension shaft portion 83c is configured by integrally fixing another member to the trunnion 83b. Piston 1 on the outer circumference of extension shaft 83c
24 are provided. The piston 124 is fitted in a cylinder 126 provided in the upper control valve body 200. An oil chamber 128 is formed above the piston 124, and an oil chamber 130 is formed below the piston 124. The oil chamber 130 on the right side of the drawing includes 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, and a roller support member.
The holes 306 and 308 provided in 83 (note that the opening of the hole 306 is closed by the ball 310) communicate with the opening of the hole 308. Also, the race 312 of the bearing 82 is provided with a hole 314. Roller support member 8 on the left side of the figure
The oil passages for 3 are almost the same (hole 302, clearance 304, hole 306
And 308) are provided, but the hole 302 has an upper oil chamber 128.
The difference is that it communicates with. Also, holes 306 and 308 are connected by an annular groove 316. The left and right pistons 124 have the same shape except that the positions of the holes 302 are different. The upper end of the piston 124 is in contact with the roller support member 83 via the spacer 132, and the lower end of the piston 124 is in contact with the cam 136 via the spacer 134. The cam 136 is attached by a bolt 138 so as to rotate integrally with the extension shaft portion 83c. The cam 136 is attached to the extension shaft 83c on the right side in FIG. 1, and the extension shaft 83c 'on the left side is connected to the line pressure regulating valve 502 as described later. The left and right friction rollers 22, the roller support member 83, etc. are basically symmetrical with respect to other points. Therefore, although the same reference numerals are used for the same members on the left and right sides, the reference numerals of the left side are added with ′ for those requiring identification of the left and right sides for explanation (trunnion 83b ′, extension shaft portion 83c ′, Oil chamber 128 ', oil chamber 130', etc.). Axis 8
Part 80a supporting the friction roller 22 and roller support member 83
It is eccentric with the portion 80b supported by. The cam 136 has a slope 140, and a link 142 swinging around a swing shaft 142a is in contact with the slope 140. When the cam 136 is rotated by this, the link 142 swings, and a shift control described later is performed. The valve 150 inputs the rotational displacement of the trunnion of the roller support member 83. The swing shaft 142a is supported by a part of a valve body 144 described later. 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 attached to the casing 67 so as to accommodate the valve body 144, the cam 136 and the like. A shift control valve 150 is provided in the lower control valve body 144. The shift control valve 150 includes a drive rod 154 rotated by a shift motor 152, a sleeve 156, and a sleeve.
Spool 158 fitted to the inner diameter of 156, and spool
And a spring 160 that presses 158 to the right in the figure. The drive rod 154 has a multi-threaded external thread 154a at its tip, and this meshes with the multi-threaded female thread 156a of the sleeve 156 (note that the transmission motor 152 is output by using the multi-threaded screw). It can be used in a large torque range and can be made smaller). The sleeve 156 has axial grooves 156b and 156c at circumferential positions opposed to each other, and the grooves 156b and 156c.
The pin 162 and the screw 163 fixed to the lower control valve body 144 enter into the inside. This allows the sleeve 156 to move axially without rotating. The end 158a of the spool 158 on the side opposite to the side in contact with the spring 160 is attached to the link 142 by the spring 160.
It is pressed by the force of. Spool 158 is land 158
b and 158c, it is possible to adjust the opening of the ports communicating with the oil passages 166 and 168, respectively. Although not shown, the end surface of the overlap margin portion with respect to each port of the land of the spool 158 has a shape cut into a two-face width. As a result, a part of the outer circumference of the land is always fitted in the inner diameter portion of the sleeve 156, and the valve stick is less likely to occur. The spool 158 is always in a predetermined axial position as shown with respect to the sleeve 156 in a stable state in which the gear ratio is kept at a predetermined value, supplies hydraulic pressure of the same pressure to the oil passages 166 and 168, and
When the spool 158 is in an unstable state during shifting, the line pressure supplied from the oil passage 164 depends on the position of the spool 158.
Allocate to 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. 4 shows the hydraulic control circuit. This hydraulic control circuit
Shift control valve 150, line pressure regulating valve 502, throttle valve 50
4, manual valve 506, lockup control valve 508,
It has a constant pressure regulating valve 510 and a constant pressure regulating valve 512, which are connected as shown in the drawing, and an oil pump.
15, high (small gear ratio) side oil chamber 516 (this is the right side oil chamber 130 and left side oil chamber 128 'in FIG. 7), low (high gear ratio) side oil chamber 518 (this is the seventh The oil chamber 128 on the right side and the oil chamber 130 'on the left side in the figure), the forward clutch 520, the reverse clutch 522, and the apply-side oil chamber 1 of the torque converter 12.
2f, the re-race side oil chamber 12b of the torque converter 12, the solenoid 528, the oil cooler 530, the 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 15 is supplied, as described later. Throttle valve 504 regulates a hydraulic pressure (throttle pressure) corresponding to the force of vacuum diaphragm 536 and outputs the resultant to oil passage 538. Shift control valve 1
The control unit 50 adjusts the distribution of the hydraulic pressure to the high-side oil chamber 516 and the low-side oil chamber 518 as described above according to the operation of the speed change motor 152, and realizes a predetermined gear ratio. The manual valve 506 supplies the line pressure supplied from the oil passage 534 to the forward clutch 520 or the reverse clutch 522 in accordance with the position of the select lever, and switches between forward and backward. The lock-up control valve 508 is adapted to the oil pressure on the apply side 12f and the oil chamber on the relacing side 12b according to the oil pressure obtained by the solenoid 528 whose duty ratio is controlled.
The supply direction and the hydraulic pressure value of the hydraulic pressure to the lockup clutch 12a are controlled to control the engagement / disengagement of the lockup clutch 12a. Constant pressure regulator 510
Regulates a constant pressure utilized by solenoid 528. Constant pressure regulating valve 512 regulates the oil pressure supplied to torque converter 12 so as not to exceed a constant value.

The line pressure regulator 502 is a spool 550, two springs 552 and 554, a sleeve 555, and a rod with a pin 556.
Has 558. The stopper 560 prevents the rod 558 from moving more than a predetermined amount. The pin 556 fits in the slit of the tip of the arm 562 which is integral with the extension shaft portion 83c 'of the trunnion 83b'. Further, as shown in FIGS. 2 and 3, the pin 556 is guided by an elongated hole 566 of a guide 564 fixed to the lower valve body 144, and is movable along this. Therefore, the rotation of the extension shaft portion 83c ′ causes the pin 556 to move along the elongated hole 566. Since the pin 556 is attached to the rod 558 as described above, the rotation of the trunnion 83b 'causes the rod 558 to rotate.
Will move in the axial direction. Rod 558 sleeve 5
55 in contact with sleeve 5 in response to movement of rod 558
55 moves in the axial direction. The sleeve 555 and the spool 550 are connected via two springs 552 and 554,
This allows the spring 5 to rotate in response to the rotation of the trunnion 83b '.
The force exerted by 52 and 554 on the spool 550 changes, and the spool 550 regulates the line pressure that changes according to the rotation amount of the trunnion 83b ', that is, the gear ratio.

On the other hand, as described above, the cam 136 is provided so as to rotate integrally with the extension shaft portion 83c of the other trunnion 83b, and the rotation of the cam 136 is transmitted via the lever 142 to the shift control valve.
Transmitted to 150. As shown in FIG. 1, the line pressure regulating valve 502 is provided on one side of a line connecting the extension shaft portions 83c and 83c ′ of the two trunnions, and the shift control valve 150 is provided on the other side.
Are provided, and both are provided in parallel with each other. By doing so, the line pressure regulating valve 502 and the shift control valve 150 are efficiently arranged, the required space is reduced, and the entire valve case can be downsized. In addition,
Valves other than the line pressure regulating valve 502 and the shift control valve 150 are actually arranged as shown in FIG.

As shown in FIG. 1, the shaft center of the rod 558 and the sleeve 555 of the line pressure regulating valve 502 are offset. As a result, the degree of freedom in arranging the line pressure regulating valve 502 is increased, and the diameter of the spool 550 can be increased.

In addition, as shown in FIG.
52a and the drive rod 154 are connected so as to transmit the rotational force by engaging the convex portion 152b and the concave portion 154a, but there is a relatively large gap between the convex portion 152b and the concave portion 154a. This is to absorb the error of the concentricity of the shaft center of the transmission motor 152 and the transmission control valve 150.

Further, it is necessary to detect the maximum gear ratio state in order to calibrate the initial signal when the maximum gear ratio state is reached. For this reason, the maximum gear ratio detection switch 800 is provided as shown in FIGS. Has been. The maximum gear ratio detection switch 800 is operated by the rod 558 of the line pressure regulating valve 502. The maximum gear ratio detection switch 800
The mounting position of can be adjusted from the outside by twisting.

(G) Effect of the Invention As described above, according to the present invention, one trunnion is connected to the line pressure regulating valve and the other trunnion is connected to the shift control valve. The line pressure can be adjusted, and the required hydraulic pressure can be efficiently obtained even in the engine braking state. Further, the line pressure regulating valve and the shift control valve can be efficiently housed in the limited space.

[Brief description of drawings]

FIG. 1 is a view showing the arrangement of valves in a hydraulic control device for a friction wheel type continuously variable transmission according to the present invention, FIG. 2 is a view of the control valve seen from below, and FIG. 3 is III- in FIG. A sectional view taken along line III, FIG. 4 is a diagram showing a hydraulic circuit, FIG. 5 is a sectional view of the entire continuously variable transmission, and FIG. 6 is an enlarged view of a friction wheel type continuously variable transmission mechanism. 6 is a sectional view taken along line VII-VII in FIG. 6, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 18 ... Input disc, 20 ... Output disc, 22 ... Friction roller, 83 ... Roller support member, 83a, 83b, 83a ', 83b'
...... Trunnion, 150 ...... Shift control valve, 502 ...... Line pressure regulator valve.

Claims (3)

[Claims] 1. An input disc, an output disc, a pair of friction rollers that frictionally contact both discs, each friction roller is rotatably supported, and is rotatable about a trunnion and movable in the trunnion axis direction. A roller support member, a hydraulic cylinder capable of moving each roller support member in the trunnion axial direction, a line pressure regulating valve for generating a line pressure according to an engine load, and a gear ratio according to an operating state. In a hydraulic control device for a friction wheel type continuously variable transmission having a shift control valve that controls the hydraulic pressure supplied to a hydraulic cylinder based on a line pressure, the rotational displacement of one trunnion is feedback-input to the shift control valve, and the other is The rotational displacement of the trunnion is input to the line pressure regulating valve together with the engine load, and the line pressure is regulated according to the gear ratio. Hydraulic control device for friction wheel continuously variable transmission, wherein. 2. The shift control valve and the line pressure regulating valve are respectively arranged on one side and the other side defined by a line connecting two trunnions in a plane orthogonal to the trunnion. A hydraulic control device for a friction wheel type continuously variable transmission according to the item. 3. The rotational displacement of the other trunnion includes an arm that rotates integrally with the trunnion, a rod with a pin that receives a pushing force from the arm, and an elongated hole that guides the pin in the axial direction. The hydraulic control device for a friction wheel type continuously variable transmission according to claim 1 or 2, wherein the hydraulic pressure is input to the line pressure regulating valve by a guide.