JPS63225754A - Hydraulic control device of friction wheel type continuously variable transmission gear - Google Patents

Abstract

PURPOSE:To decrease loss of an oil pump by adjusting the line pressure in accordance with a throttle pressure and a change gear ratio and enlarging the effects of changes in the change gear ratio on the line pressure on the small change gear ratio side compared with the large change gear ratio side. CONSTITUTION:A throttle valve 504 has a line pressure of an oil passage 534 as an initial pressure and outputs its throttle pressure to an oil passage 538. When a change gear ratio is larger than a specified value, the line pressure becomes high with increasing the throttle pressure. And the line pressure becomes high with increasing the change gear ratio. On the other hand, when the change gear ratio becomes below the specified value, the throttle pressure becomes equal to the line pressure because a theoretical value of the throttle pressure becomes above the line pressure. As a result, the line pressure receiving area of a line pressure governor valve 502 is reduced and the line pressure greatly changes so as to maintain a balancing condition relative to the changes in the change gear ratio. Namely, the change gear ratio becomes smaller on the small change gear ratio side, so that the line pressure becomes lower. Thus, an oil hydraulic characteristics approximate to a theoretically required line pressure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hydraulic control device for a friction wheel type continuously variable transmission.

(B) Prior Art A conventional hydraulic control device for a friction wheel type continuously variable transmission is disclosed in, for example, Japanese Patent Application Laid-Open No. 119864/1983. This shows a friction wheel continuously variable transmission equipped with a human-powered disc, an output disc, and a power roller.
By moving the support that supports the power roller in accordance with the hydraulic pressure applied to the hydraulic chamber, the contact state between the power roller and both discs is changed, and the gear ratio between the manual disc and the output disc is continuously adjusted. It is variable. The line pressure, which is the source of the hydraulic pressure supplied to the hydraulic working chamber, is set to increase approximately in proportion to the torque on the human-powered disk side. That is, the hydraulic pressure in the hydraulic chamber on the manual disk side is fed back to the pressure increasing side boat of the regulator valve.

(c) Problems to be solved by the invention However, the conventional F! f. In the hydraulic control system of a friction wheel type continuously variable transmission, if torque is applied manually from the output disk side, the hydraulic pressure may become low and shift control may not be performed, so the line pressure should be set with some margin. It is necessary to set it high. This increases the load on the oil pump and increases power loss. The present invention
The purpose of this invention is to solve such problems and to obtain hydraulic characteristics that are more similar to the actually required hydraulic pressure.

(d) Means for solving the problem The present invention adjusts the line pressure according to the throttle pressure and the gear ratio, and the change in the gear ratio is more sensitive to the line pressure on the small gear ratio side than on the large gear ratio side. The above problem is solved by increasing the influence. That is, the line pressure regulating valve and the throttle valve of the hydraulic control device for the friction wheel type continuously variable transmission according to the present invention are such that when the lock-up clutch is released and the gear ratio is smaller than a predetermined value, the throttle pressure is lower than the line pressure. The pressure is equal to the line pressure, and the change in line pressure with respect to a change in the gear ratio is configured to be larger than when the gear ratio is thicker than a predetermined value.

(e) When the operating gear ratio is larger than a predetermined value, the line pressure changes according to the throttle pressure and the gear ratio.

That is, as the throttle pressure increases, the line pressure also increases, and as the gear ratio increases, the line pressure increases. On the other hand, when the gear ratio becomes smaller than the predetermined value, the theoretical value of the throttle pressure becomes higher than the line pressure, so the throttle pressure becomes equal to the line pressure. Therefore, the line pressure receiving area of the line pressure regulating valve decreases, and the line pressure changes significantly in order to maintain a balanced state against changes in the gear ratio. That is, on the small gear ratio side, the line pressure becomes lower as the gear ratio becomes smaller. As a result, line pressure characteristics closer to the theoretically required line pressure can be achieved, and oil pump loss can be reduced.

(F) Embodiment FIG. 5 shows the overall structure of a continuously variable transmission. A torque converter 1 is mounted on a drive plate 10 that is integrated with the output shaft of the engine.
2 are connected. The torque converter 12 is equipped with a lock-up clutch 12a, and can mechanically connect or disconnect the pump impeller 12c on the input end and the turbine runner 12d on the output side by controlling the oil pressure in the lock-up oil chamber 12b. be. An 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 placed on the opposite side of the torque converter 12 across a friction wheel type continuously variable transmission mechanism 16, which will be described later. Also,
A turbine runner 12d of the torque converter 12 is connected to a hollow human power shaft 14. An EA vehicle type continuously variable transmission mechanism 16 is connected to the human power shaft 14 . The J"lJ vehicle type continuously variable transmission mechanism 16 includes a manual disk 18, an output disk 20, a friction roller 22 that transmits rotational force between the two,
have. Human power disk 18 and output disk 20
The contact surface with the friction roller 22 is a toroidal surface.

The inclination of the shaft 24 of the friction roller 22 can be adjusted by a mechanism shown in FIG. 6 and described below. A human power disk 18 is connected to the human power shaft 14, and a gear 2 is connected to the force output disk 20.
6 are provided so as to rotate together.

ffl IIL 26 is the gear 3 integrated with the idler shaft 28
It meshes with 0. The idler shaft 28 is provided with teeth 'tJ-32 that always rotate integrally with the idler shaft 28 and a gear 34 that is rotatably supported by six gears relative to the idler shaft 28.

The gear 34 can be connected to the gear 30 by a reverse clutch 36 so as to rotate together with the gear 30 . The idler shaft 28 is configured to rotate only in the forward direction and not in the reverse direction by a one-way clutch 31 attached to the casing.

This is to prevent the friction wheel type continuously variable transmission mechanism 16 from rotating in a direction opposite to the engine rotation direction due to reverse driving force from the wheel side. Another idler gear 38 arranged parallel to the idler shaft 28 rotatably supports a gear 40, and is connected to teeth tlt42 so as to rotate together at all times. The gear 40 is the forward clutch 4
Idler Il by 4! It can be connected to rotate together with Ih38. Gear 40 meshes with gear 32.

Gear 34 is always meshed with final gear 48.

A pair of binion gears 52 and 54 constituting a differential device 50 are attached to the final gear 48, and a pair of side gears 56 and 5 are attached to the binion gears 52 and 54.
8 are in mesh with each other, and the output shafts of the side gears 56 and 58 are connected to each other. With this configuration, when the plane advance clutch 44 is engaged, the output shaft rotates in the forward direction, and when the reverse clutch 36 is engaged, the output shaft is rotated in the backward direction. Further, by controlling the contact state of the friction roller 22 of the friction wheel type continuously variable transmission mechanism 16 with the input disk 18 and the output disk 20, the speed ratio can be changed continuously.

FIG. 6 shows the friction wheel type continuously variable transmission mechanism 16 in detail. The human power shaft 14 is rotatably supported by a casing 67 via a ball bearing 65 and a needle bearing 66. Note that a spacer 68 is provided between the human power shaft 14 and the hall hair ring 65. spacer 68;
Loading nut 6 screwed into human power shaft 14
A disc spring 70 is provided between the disc spring 9 and the disc spring 9. As a result, the reaction force of the disc spring 70 acts to push the human power shaft 14 to the right in the figure. The tip of the loading nut 69 is manually operated l1
It is prevented from loosening by the pin 71 that enters the groove 14a of 4114. In addition, a plurality of holes 69a are provided for inserting the pin 71, and a plurality of grooves 14a are also provided for the input shaft 14, and by a combination of both, the loading nut 69
The fixed position can be finely adjusted. pin 71
The removal is stopped by Hatosuf 2. An output disk 20 is rotatably supported on the human power shaft 14 via a bearing 73. The output disk 20 has a symmetrical position 2
Output gears 26 are provided so as to rotate together via keys 74 placed at certain locations. Gear 26 is supported by casing 67 via ball bearings 75. Further, a human-powered disk 18 is provided on the human-powered shaft 14 so as to be rotatable and movable in the axial direction via a bearing 76 . A cam flange 77 is provided on the back side of the human-powered disk 18, that is, on the side opposite to the side facing the output disk 20.
is provided. The cam flange 77 is spline-coupled to the manpower shaft 14 and is prevented from moving to the left in FIG. 6 by a shoulder 78 of the manpower shaft 14. A cam roller 79 is provided between the cam surfaces 18a and 77a of the manual 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 human-powered disk 18 rotate relative to each other, a force is generated that presses the human-powered disk 18 to the right in FIG. a friction roller 22 disposed within a toroidal groove formed by the opposite sides of the input disk 18 and the output disk 20;
is rotatably supported on 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 a roller support member 83. The friction roller 22, the ball bearing 82, and the roller support member 83 are prevented from being removed by snap rings 84 and 85 provided at both ends of the shaft 80. A sleeve 86 is inserted into the inner diameter portion of the input shaft 14, and is prevented from being removed by a snap ring 97.

The diameter of the sleeve 86 other than both ends where O-rings 96 and 95 are provided is smaller than the inner diameter of the human power shaft 14, and an oil passage 88 is formed by a gap having an annular cross section therebetween. The manpower shaft 14 is provided with radial holes 94, 93, 92 and 91 communicating with this oil passage 88. Also, human power IP! 1114 has a casing 67
A groove 101 and a hole 102 for receiving oil from the hole 90 are provided. Groove 101 is sealed by seal ring 103. An oil pump drive shaft 87 passes through the inner diameter portion of the sleeve 86 . A gap having an annular cross section between the inner diameter of the sleeve 86 and the outer diameter of the oil pump drive shaft 87 forms an oil passage 89 for hydraulic pressure for lockup control of the torque converter 12 .

FIG. 7 shows a cross section taken along the line Vll--Vll in FIG. 6.

The roller support member 83 described above is rotatably and vertically movably supported by spherical bearings 110 and 112 at the upper and lower rotating shaft portions 83a and 83b. The spherical bearing 11O 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. Further, the spherical bearing 112 is also supported by a bearing support member 118, and the bearing support member 118 is supported by a link post 120 fixed to the upper control valve body 200. Note that the upper control valve body 200 is attached to the casing 67.

The roller support member 83 has an extended shaft portion 83c provided concentrically with the rotating shaft portion 83b. In addition, the extension shaft portion 83c
is constructed by integrally fixing another member to the rotating shaft portion 83b. A piston 12 is provided on the outer periphery of the extended shaft portion 83c.
4 is provided. The piston 124 fits within a cylinder 126 provided in the upper control valve body 200. Oil chamber 128 above the piston 124
is formed, and an oil chamber 130 is formed below the piston 124. The oil chamber 130 on the right side of the figure includes a hole 302 provided in the piston 124, a gap 304 between the piston 124 and the small diameter portion of the extended shaft portion 83c, and holes 306 and 308 provided in the roller support member 83 (note that the hole 306 The opening of the hole 308 is sealed by a ball 310).
It communicates with the opening. Further, a hole 314 is provided in the race 312 of the bearing 82. Almost the same oil passage (hole 302
, a gap 304, and holes 306 and 308), except that the hole 302 communicates with the upper oil chamber 128. Additionally, the holes 306 and 308 are annular grooves 31
connected by 6. In addition, the left and right pistons 12
No. 4 has the same shape except that the position of the hole 302 is 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 together with the extended shaft portion 83c.

The cam 136 is attached to the right extension shaft portion 83c in FIG. 7, and is not provided to the left extension shaft portion 83c. In other respects, the left and right friction rollers 22, roller support members 83, etc. are basically symmetrical.

Note that the portion 80a of the shaft 80 that supports the ff50-ra 22
and the portion 80b supported by the roller support member 83 are eccentric. The cam 136 has a slope 140 with which a link 142 contacts. As a result, cam 13
By rotating 6, the link 142 can be swung. Upper control valve body 200
A lower control valve body 144 is attached to the lower surface of the casing 67 via a separate plate 200, and an oil pan 146 is attached to the casing 67 to accommodate the valve body 144, cam 136, and the like. A speed change control valve 150 is provided in the lower control valve body 144. The speed change control valve 150 includes a drive rod 15 that is rotationally driven by a speed change motor 152.
4, a sleeve 156, a spool 158 fitted into the inner diameter portion of the sleeve 156, and a spring 160 that presses the spool 158 rightward in the figure.

The drive rod 154 has a threaded portion 154a at its tip, which engages with a female threaded portion 156a of the sleeve 156. The sleeve 156 has an axial groove 156b into which a bottle 162 secured to the lower control valve body 144 is received. This allows the sleeve 156 to move in the axial direction without rotating. End 158a of the spool 158 opposite to the side that contacts the spring 160
is pressed against the link 142 mentioned above by the force of the spring 160. Spool 158 is land 158a
and 158b, which allow oil passages 1 and 158b, respectively.
The opening degree of the boat communicating with 66 and 168 can be adjusted. When the gear ratio is constant, the spool 158 is always at a predetermined axial position relative to the sleeve 156 as shown in the figure.
Hydraulic pressure of the same pressure is supplied to oil passages 166 and 168, and when the spool 15 is in a gear shift state, the line pressure supplied from oil passage 164 is applied to oil passage 166 and oil passage 1 according to its position.
Allocate to 68. The oil passage 168 is connected to the oil chamber 128 on the right side of the figure and the oil chamber 130 on the left side of the figure. In addition, the oil passage 166 is connected to the oil chamber 130 on the right side in the figure and the oil chamber 12 on the left side in the figure.
8 is connected.

Figure 1 shows the hydraulic control circuit. This hydraulic control circuit includes a speed change control valve 150, a line pressure regulating valve 502, and a throttle valve 5.
04, a manual valve 506, a lock-up control valve 508, a constant pressure regulating valve 510, and a constant pressure regulating valve 512, which are connected as shown in the figure. ) side oil chamber 516 (
Oil chamber 130 on the II side and oil chamber 128 on the left side in Fig. 7)
, low (large gear ratio) side oil chamber 518 (11 side oil chamber 128 and left side oil chamber 130 in FIG. 7), 11rf Shinkawa clutch 520, reverse clutch 522, apply side oil chamber of torque converter 12 12f, torque converter 1
It is also connected to the release side oil chamber 12b of No. 2, a solenoid 528, an oil cooler 530, a slip circuit 532, etc. as shown in the figure. The line pressure regulating valve 502 is the oil pump 5
The oil pressure (line pressure) of the oil passage 534 to which the discharge pressure from 14 is supplied is regulated as described later. The throttle valve 504 regulates oil pressure (throttle pressure) corresponding to the force of the vacuum diaphragm 536 and outputs it to the oil path 538. Shift control: #-150 adjusts the distribution of 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 variable speed motor 152, thereby realizing a predetermined gear ratio. The °7 null valve 506 supplies line pressure supplied from the oil passage 534 to the forward clutch 520 or the reverse clutch 522 depending on the position of the select lever, thereby switching between forward and backward movement.

The lock-up control valve 508 adjusts the direction and value of oil pressure supplied to the apply-side oil chamber 12f and the release-side oil chamber 12b according to the oil pressure obtained by the solenoid 528 whose duty ratio is controlled, and engages the lock-up clutch 12a. - Control release. Constant pressure regulating valve 510
regulates the constant pressure utilized by solenoid 528. Constant pressure regulating valve 512 regulates the hydraulic pressure supplied to torque converter 12 so that it does not exceed a fixed value.

Next, the line pressure regulating valve 502EL and the throttle valve 504
will be explained in more detail. The throttle valve 504 outputs a throttle pressure PTH to the oil passage 538 using the line pressure of the oil passage 534 as a source pressure, and the pressure regulation state of the throttle valve 504 is expressed by the following equation.

F□ +s, xPo =S2 XPTHF, ...
Pushing force Sl of the vacuum diaphragm 536...Pressure receiving area S2 of the spool on which the oil pressure of the boat 550 acts...Pressure receiving area PD of the spool on which the oil pressure of the boat 551 acts...Duty pressure (hydraulic pressure of the oil passage 553) Therefore , PTll=FD/S2+(Sl/S2
) becomes X PD.

Note that Po becomes 0 when the lock-up clutch is engaged, and becomes a predetermined constant pressure when the lock-up clutch is released.

On the other hand, the line pressure P regulated by the line pressure regulating valve 502 has the following relationship.

FS +S3 XPTll=S4 XPLF3・
... Pushing force S3 by springs 552 and 554 ... Pressure receiving area S of the spool on which the oil pressure of the boat 702 acts, ... Pressure receiving area of the spool on which the oil pressure of the boat 704 acts, Therefore, PL = Fs /S4 + (S3 / S4)XPTH
The throttle pressure PTH and line pressure PL obtained from the above formula are calculated to have the relationship shown in Figure 2 when the lock-up clutch is released, so that S1% S2, S
3.S4. Set the values of FD, PD, and FS. In reality, in the region where the theoretical value of the throttle pressure based on the equation for the pressure regulation state of the throttle valve 504 described above in Fig. 2 is higher than the line pressure (on the small gear ratio side), the actual throttle pressure is equal to the line pressure. They will be equal (because the throttle pressure is based on the line pressure). Therefore, PL obtained from the above formula is Pi, = Fs / (S4 S3) (however,
S4 > 33), and the influence of Fs becomes large. In other words, the influence of the gear ratio on the line pressure increases. This actually results in line pressure characteristics as shown in FIG. This line pressure characteristic is more similar to the theoretically required line pressure shown by the broken line in FIG. 3, especially on the small gear ratio side.

On the other hand, when the lock-up clutch is engaged, P+, =F! calculated from equations 1 and 2! l/S4 +S3/(S4 XS2)X
The characteristic is calculated by the FD formula, and the line pressure as shown in FIG. 4 is obtained.

As a result, it is possible to reduce the line pressure in the region on the small gear ratio side when the lock-up clutch is released, and as shown in FIG. 3, it is possible to obtain line pressure characteristics that are more similar to the required line pressure.

Although not directly related to the present invention, as shown in FIG. 1, the oil cooled by the oil cooler 530 flows into the slipping circuit 532 (the oil hole 9 for lubricating the friction roller 22 shown in FIG. 6).
3, etc.), thereby providing efficient lubrication and cooling. In addition, a constant pressure regulating valve 51 is provided in the oil passage 850 for reservoir and lubricating.
Oil pressure is supplied from 2, but in addition to this, the amount of lubricating oil can be increased according to the engine load by connecting the line pressure oil path 534 or the throttle pressure oil path 538 to the oil path 850 via an orifice. Can be done.

(g) As described in detail, according to the present invention, the line pressure is regulated according to the gear ratio and the throttle pressure, and on the small gear ratio side, the throttle pressure is made equal to the line pressure, and the gear ratio By increasing the influence of .

[Brief explanation of drawings]

Fig. 1 is a diagram showing a hydraulic circuit including a hydraulic control device for a friction wheel type continuously variable transmission according to the present invention, Fig. 2 is a diagram showing the relationship between line pressure and throttle pressure, and Fig. 3 is a diagram showing a lock-up clutch. Figure 4 is a diagram showing line pressure characteristics when lock-up is engaged, Figure 5 is a sectional view of the entire continuously variable transmission, and Figure 6 is a diagram showing the friction wheel type continuously variable transmission mechanism. An enlarged view, Fig. 7 shows VII-VII of Fig. 6.
It is a sectional view along M. 502... Line pressure regulating valve, 504... Throttle valve.

Claims (1)

[Scope of Claims] It has a line pressure regulating valve and a throttle valve, and both valves are connected so that the line pressure obtained by the line pressure regulating valve increases in accordance with the increase in the throttle pressure obtained by the throttle valve. In addition, in a hydraulic control system for a friction-type continuously variable transmission in which the line pressure regulating valve is configured to change line pressure according to the gear ratio, when the lock-up clutch is released, the gear ratio is lower than a predetermined value. If the gear ratio is smaller than the predetermined value, the throttle pressure becomes equal to the line pressure, and the configuration is such that the change in the line pressure with respect to a change in the gear ratio is larger than when the gear ratio is larger than a predetermined value. A hydraulic control device for a friction wheel type continuously variable transmission.