Automatic transmission hydraulic control throttle valve
AssigneeNissan Motor Co., Ltd.
InventorTetsuya Iijima
Life of this patent
Estimating the term…
Abstract
A valve spool and a piston are disposed substantially parallel to each other and are pivotably connected with a lever which is movable by the accelerator pedal of a prime mover. The force differential biasing the valve spool to withstand the force of the lever tending to move the valve spool is approximately zero. The valve spool has a valve land with a width equal to that of a port connected with a throttle pressure passage, and a constant neutral position in which the valve land registers with the port and hydraulic pressure in the passageway is equal to a throttle pressure depending on the position of the accelerator pedal. The piston is biased by the hydraulic pressure in the passageway and a spring in opposite directions to cause the valve spool to occupy the netural position.
Claims5
A throttle valve of a hydraulic control system of an automatic power transmission of a vehicle driven by a prime mover, comprising a lever pivotably connected at a first portion with a prime mover acceleration control member, a valve spool pivotably connected with said lever at a second portion which is spaced from said first portion along the length of said lever and having a constant neutral position, a passageway into and from which hydraulic fluid is delivered and discharged to increase and reduce the hydraulic pressure in said passageway when said valve spool is moved from said neutral position in axial, opposite directions, the hydraulic pressure in said passageway being equal to a throttle pressure depending on the position of said control member when said valve spool is in said neutral position, a piston pivotably connected with said lever at a third portion which is spaced from said first and second portions along the length of said lever, a spring urging said piston to prevent said piston from being moved by said lever when said control member is moved in a prime mover output increasing direction, said piston communicating with said passageway and being biased by the hydraulic pressure in said passageway against the action of said spring, said lever being rotatable around said piston by said control member to move said valve spool in said opposite directions when said control member is moved in prime mover output increasing and reducing directions, said piston being moved in response to the hydraulic pressure in said passageway lower and higher than said throttle pressure to move said valve spool from said neutral position in said opposite directions to cause increase and reduction in the hydraulic pressure in said passageway to said throttle pressure.
Dependencies are inferred from the claim text.