Line pressure regulator valve

Claim 2

A line pressure regulator valve for regulating line pressure in a hydraulic control system for an automotive automatic power transmission, comprising a valve body including first and second inlets communicating with a source of pressure fluid, an outlet communicating with a line pressure conduit connected to said hydraulic control system, and a drain to discharge an excess of fluid therethrough, a slidable valve spool having at least a first land and a second land, said first land varying the degree of fluid communication between said first inlet and said drain thereby varying the level of pressurized fluid to be delivered to said outlet, and said second land varying the degree of fluid communication between said first inlet and said outlet thereby varying the flow Rate of pressurized fluid to be delivered to said line pressure conduit, spring means for biasing said valve spool in one direction so as to cause the first land thereof to decrease the degree of fluid communication between said first inlet and said drain and to cause the second land thereof to increase the degree of fluid communication between said first inlet and said outlet, amplifying means cooperating with said valve spool for varying the degree of fluid communication between said first inlet and said drain in accordance with a throttle pressure produced in said hydraulic control system so as to vary the level of pressurized fluid to be delivered to said outlet in accordance with said throttle pressure, conduit means communicating with said second inlet and said outlet and leading to said line pressure conduit, first flow restricting means provided in said second inlet for restricting the flow rate of pressurized fluid acting on said valve spool so as to gradually move said valve spool in another direction against the forces of said spring means and said amplifying means so as to cause said first land of said valve spool to increase the degree of fluid communication between said first inlet and said drain and to cause said second land of said valve spool to decrease the degree of fluid communication between said first inlet and said outlet, and second flow restricting means provided directly between said source of pressurized fluid and said conduit means for restricting the flow rate of pressurized fluid to be supplied to said line pressure conduit through said conduit means so as to gradually increasing the level of fluid pressure in said line pressure conduit, said valve spool being initially moved in said one direction by the action of said amplifying means to increase the degree of fluid communication between said first inlet and said outlet while decreasing the fluid communication between said first inlet and said drain thereby to allow a high level of fluid pressure to be passed into said conduit means at a relatively high rate, said high level of pressurized fluid delivered to said conduit means being applied through said first flow restricting means to said valve spool so as to cause the same to move in another direction thereby decreasing the degree of fluid communication between said first inlet and said outlet port for decreasing the flow rate pressurized fluid to be admitted to said line pressure conduit.

Claim 3

A line pressure regulator valve according to claim 1, wherein said slidable valve spool also has third and fourth lands, the pressurized fluid in said second inlet acting on a differential area between said third and fourth lands to move said valve spool in a direction against the forces of said means and said amplifying means.

Claim 4

A line pressure regulator valve according to claim 1, wherein said amplifying means includes a slidable valve spool having a push rod cooperating with said first land of said valve spool.

Claim 5

A line pressure regulator valve for regulating line pressure in a hydraulic control system for an automotive automatic power transmission which hydraulic control system includes a source of pressurized fluid and a throttle valve adapted to produce a throttle pressure in accordance with an engine output torque, said line pressure regulator valve comprising a valve body including first and second inlets communicating with said source of pressurized fluid, an outlet communicating with a line pressure conduit connected to said hydraulic control system, and a drain to discharge an excess of pressurized fluid therethrough, a slidable valve spool having first, second, third and fourth spaced lands formed thereon, said first land of said valve spool serving to vary the degree of fluid communication between said first inlet and said drain so as to vary the level of pressurized fluid to be delivered to said outlet, said second land of said valve spool serving to vary the degree of fluid communication between said first inlet and said outlet port so as to vary the flow rate of pressurized fluid to be admitted to said line pressure conduit, spring means for biasing said valve spool in one direction so as to cause the first land of said valve spool to decrease the degree of fluid communication between said first inlet and said drain and to cause said second land of said valve spool to increase the degree of fluid communication between said first inlet and said outlet, amplifying means having means cooperating with said first land of said valve spool and responsive to the throttle pressure produced by said throttle valve for moving said valve spool in said one direction so as to vary the level of pressurized fluid to be delivered to said outlet in accordance with the throttle pressure, conduit means communicating with said outlet and said second inlet and leading to said line pressure conduit, first flow restricting means provided in said second inlet for restricting the flow rate of pressurized fluid to be applied to said third and fourth lands of said valve spool for gradually moving said valve spool in another direction against the forces of said spring means and said amplifying means to cause said first land of said valve spool to increase the degree of fluid communication between said first inlet and said drain and to cause said second land of said valve spool to decrease the degree of fluid communication between said first inlet and said outlet, and second flow restricting means provided directly between said source of pressurized fluid and said conduit means for restricting the flow rate of pressurized fluid to be supplied to said line pressure conduit through said conduit means for gradually increasing the level of pressurized fluid in said line pressure conduit, said valve spool being initially moved in said one direction by the action of said amplifying means to increase the degree of fluid communication between said first inlet and said outlet ports thereby to allow initially a relatively high rate of fluid flow to said line pressure conduit through said conduit means and subsequently moved in said another direction by the pressurized fluid acting on the differential area between said third and fourth lands of said valve spool against the forces of said spring means and said amplifying means to decrease the degree of fluid communication between said first inlet and said outlet thereby to subsequently decrease the rate of fluid flow to be admitted to said line pressure conduit.

Claim 6

A line pressure regulator valve for regulating line pressure in a hydraulic control system for an automotive automatic power transmission which hydraulic control system includes a source of pressurized fluid and a throttle valve adapted to produce a throttle pressure in accordance with an engine output torque, said line pressure regulator valve comprising a valve body including first and second inlets communicating with said source of pressurized fluid, an outlet communicating with a line pressure conduit connected to said hydraulic control system, and a drain to discharge an excess of pressurized fluid therethrough, a slidable valve spool having first, second, third and fourth spaced lands formed thereon, said first land of said valve spool serving to vary the degree of fluid communication between said first inlet and said drain so as to vary the level of pressurized fluid to be delivered to said outlet, said second land of said valve spool serving to vary the degree of fluid communication between said first inlet and said outlet port so as to vary the flow rate of pressurized fluid to be admitted to said line pressure conduit, spring means for biasing said valve spool in one direction so as to cause the first land of said valve spool to decrease the degree of fluid communication between said first inlet and said drain and to cause said second land of said valve spool to increase the degree of fluid communication between said first inlet and said outlet, amplifying means having means cooperating with said first land of said valve spool and responsive to the throttle pressure produced by said throttle valve for moving said valve spool in said one direction so as to vary the level of pressurized fluid to be delivered to said outlet in accordance with the throttle pressure, conduit means communicating with said outlet and said second inlet and leading to said line pressure conduit, first flow restricting means provided in said second inlet for restricting the flow rate of pressurized fluid to be applied to said third and fourth lands of said valve spool for gradually moving said valve spool in another direction against the forces of said spring means and said amplifying means to cause said first land of said valve spool to increase the degree of fluid communication between said first inlet and said drain and to cause said second land of said valve spool to decrease the degree of fluid communication between said first inlet and said outlet, and second flow restricting means provided directly between said source of pressurized fluid and said conduit means for restricting the flow rate of pressurized fluid to be supplied to said line pressure conduit through said conduit means for gradually increasing the level of pressurized fluid in said line pressure conduit, said valve spool being initially moved in said one direction by the action of said amplifying means to increase the degree of fluid communication between said first inlet and said outlet ports thereby to allow initially a relatively high rate of fluid flow to said line pressure conduit through said conduit means and subsequently moved in said another direction by the pressurized fluid acting on the differential area between said third and fourth lands of said valve spool against the forces of said spring means and said amplifying means to decrease the degree of fluid communication between said first inlet and said outlet thereby to subsequently decrease the rate of fluid flow to be admitted to said line pressure conduit.