EP0061732A2 — Hydraulic control system for continuously variabl…

Claim 1

Independent Claim 274 words

A continuously variable V-belt transmission comprising: a continuously variable V-belt transmission unit having a drive shaft; a hydrodynamic transmission unit having an output drivingly connected to the drive shaft of the continuously variable V-belt transmission unit; the continuously variable V-belt transmission unit having a V-belt running over a drive and a driven pulley, each having cylinder chamber and two conical discs, one conical disc of the drive pulley being secured to the drive shaft, one conical disc of the driven pulley being secured to a driven shaft, the other conical disc of the drive pulley being controllably movable in an axial direction of the drive shaft in response to the fluid pressure in the cylinder chamber thereof, the other conical disc of the driven pulley being controllably movable in an axial direction of the driven shaft in response to the fluid pressure in the cylinder chamber thereof; means responsive to state of said hydrodynamic transmission unit for producing a signal indicative oJ the state of the hydrodynamic transmission unit; throttle opening degree irrespective of the state when the torque multiplication is effected or not, so that the line pressure is modulated always in response to the engine output. The manner of decrease in the line pressure upon establishing the lock-up state of the torque converter 12 is continuous and not in a step like manner as is the case in the first embodiment. pumping means for the hydraulic fluid; and line pressure regulator valve means for regulating the fluid supplied by said pumping means in response to said signal to provide a line pressure variable depending upon the state of the hydrodynamic transmission unit.

Claim 2

Dependent Claim 274 words

A continuously variable V-belt transmission comprising: a continuously variable V-belt transmission unit having a drive shaft; a hydrodynamic transmission unit having an output drivingly connected to the drive shaft of the continuously variable V-belt transmission unit; the continuously variable V-belt transmission unit having a V-belt running over a drive and a driven pulley, each having cylinder chamber and two conical discs, one conical disc of the drive pulley being secured to the drive shaft, one conical disc of the driven pulley being secured to a driven shaft, the other conical disc of the drive pulley being controllably movable in an axial direction of the drive shaft in response to the fluid pressure in the cylinder chamber thereof, the other conical disc of the driven pulley being controllably movable in an axial direction of the driven shaft in response to the fluid pressure in the cylinder chamber thereof; means responsive to state of said hydrodynamic transmission unit for producing a signal indicative oJ the state of the hydrodynamic transmission unit; throttle opening degree irrespective of the state when the torque multiplication is effected or not, so that the line pressure is modulated always in response to the engine output. The manner of decrease in the line pressure upon establishing the lock-up state of the torque converter 12 is continuous and not in a step like manner as is the case in the first embodiment. pumping means for the hydraulic fluid; and line pressure regulator valve means for regulating the fluid supplied by said pumping means in response to said signal to provide a line pressure variable depending upon the state of the hydrodynamic transmission unit.

Claim 3

Dependent Claim 35 words

A continuously variable V-belt transmission as claimed in claim 1, including means connected to- said line pressure regulator valve means for regulating fluid supply to and discharge from at least one of the cylinder chambers.

Claim 4

Dependent Claim 33 words

A continuously variable V-belt transmission as claimed in claim 1 or 2, wherein said hydrodynamic transmission unit includes lock-up means operative when engaged to lock the hydrodynamic transmission unit in a lock-up mode.

Claim 5

Dependent Claim 48 words

A continuously variable V-belt transmission as claimed in claim 3, including control means for engaging said lock-up means and lock-up valve means communicating with said control means via a fluid conduit and operative to control fluid supply to and discharge from said control means via the fluid conduit.

Claim 6

Dependent Claim 33 words

A continuously variable V-belt transmission as claimed in claim 4, wherein said means for producing the signal includes means for conducting the fluid in said fluid conduit to said line pressure regulator valve.

Claim 7

Dependent Claim 153 words

A continuously variable V-belt transmission as claimed in claim 5, wherein said lock-up means includes a clutch directly connecting a pump impeller of said hydrodynamic transmission unit with a turbine runner thereof and said control means includes a lock-up clutch chamber which communicates with said fluid conduit and operative to engage said clutch when the fluid is discharged from the lock-up chamber by said lock-up valve and to release said clutch when the fluid is supplied to the lock-up chamber by said lock-up valve means, and wherein said line pressure regulator valve means is formed with a port and operative to increase the level of the line pressure when the fluid is supplied to said port and said means for conducting the fluid is connected to said port, whereby said line pressure regulator valve means reduces the level of line pressure when said lock-up valve means discharges the fluid from said lock-up chamber.

Claim 8

Dependent Claim 76 words

A continuously variable V-belt transmission as claimed in claim 6, wherein said lock-up valve means communicates with the cylinder chamber of the drive pulley and supply the fluid to said fluid conduit when the fluid pressure in the cylinder chamber of the drive pulley is lower than a predetermined value and discharges the fluid from said fluid conduit when the fluid pressure in the cylinder chamber of the drive pulley is higher than said predetermined value.

Claim 9

Dependent Claim 52 words

A continuously variable V-belt transmission as claimed in any one of claims 1 through 4, wherein said hydrodynamic transmission unit includes a stator and wherein said means responsive to the state of said hydrodynamic unit is responsive to stator reaction of said stator to produce the signal indicative of the stator reaction.

Claim 10

Dependent Claim 37 words

A continuously variable V-belt transmission as claimed in claim 8, wherein said line pressure regulator valve means is responsive to output of an engine and also to a reduction ratio of the continuously variable V-belt transmission unit.

Claim 11

Dependent Claim 71 words

A continuously variable V-belt transmission as claimed in claim 8 or 9, wherein said means responsive to the state of the hydrodynamic transmission unit comprises a reaction shaft carrying the stator via a one-way clutch, a lever connected to the reaction shaft for rotation therewith, and a pressure regulator valve means responsive to said lever for supplying fluid pressure indicative of the stator reaction to said line pressure regulator valve means.

Claim 12

Dependent Claim 60 words

A continuously variable V-belt transmission as claimed in claim 10, wherein said line pressure regulator valve means is formed with a port and operative to increase the level of the line pressure as the fluid pressure supplied to said port increases, whereby said line pressure regulator valve means reduces the level of the line pressure as the stator reaction decreases.

Hydraulic control system for continuously variable V-belt transmission with hydrodynamic transmission unit

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