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US 6,076,552 AGranted
Valve structure for hydraulic circuit
AssigneesNissan Motor Co., Ltd., Tosok Corporation
InventorsTeruyasu Takahashi, Hidenori Sakai
Life of this patent
Estimating the term…
Abstract
A valve comprises a spool with a land received in a bore of a valve body. The land is formed with at least one transfer passage. The land and cylindrical inner wall of the bore cooperate with each other to prevent any passage other than the transfer passage from opening between an inlet port and an outlet port. The transfer passage is always open to the outlet port and selectively uncovered by the cylindrical inner wall to communicate with the inlet port in response to movement of the spool.
Claims13
A hydraulic control circuit for an automatic transmission, comprising:
- an oil pump as a source of hydraulic fluid;
- a system pressure line connected to said oil pump;
- a pressure regulator valve consisting essentially of:
- a valve body formed with a bore having a longitudinal center line, said valve body being formed with an inlet port connected to said system pressure line and an outlet port,
- said valve body including a cylindrical inner wall defining said bore and formed with an inflow groove communication with said inlet port and an outflow groove communication with said outlet port, said inflow and outflow grooves being recessed from said bore into the cylindrical inner wall and spaced from each other along said longitudinal center line to define therebetween a cylindrical inner wall segment,
- said cylindrical inner wall segment having an edge adjacent said inflow groove;
- and
- a spool within said bore for movement along said longitudinal center line, said spool including a land opposed to said cylindrical inner wall segment, said land being in sliding fit to said cylindrical inner wall segment during movement of said spool to close a clearance between said land and said cylindrical inner wall segment,
- said land being formed with a plurality of transfer passages bounded within said land, each of said plurality of transfer passages being in the form of a groove that extends along said longitudinal center line,
- said plurality of transfer passages being separated from each other, each of said plurality of transfer passages having one end wall and other end wall and extending from said one end wall to said other end wall, each of said plurality of transfer passages having a predetermined section extending from said one end wall to a point between said one end wall and said other end wall,
- said predetermined section of each transfer passage being opposed to said cylindrical inner wall segment and prevented from communicating with said inflow groove when said spool assumes a predetermined position relative to said valve body,
- said predetermined section of each transfer passage being brought into opposed relation to said inflow groove gradually as said spool moves from said predetermined position within a predetermined stroke of movement of said spool relative to said valve body,
- said edge of said cylindrical inner wall segment and said predetermined section defining various flow cross sectional areas as said spool moves from said predetermined position within said predetermined stroke of movement of said spool relative to said valve body.
10 more elements
A valve consisting essentially of:
- a valve body formed with a bore having a longitudinal center line, said valve body including a cylindrical inner wall and two end walls spaced along said longitudinal center line and interconnected by said cylindrical inner wall to define said bore,
- said valve body being formed with an inflow groove that is recessed from said bore into said cylindrical inner wall,
- said valve body being formed with an outflow groove that is recessed from said bore into said cylindrical inner wall,
- said inflow and outflow grooves dividing said cylindrical inner wall into a plurality of wall segments including a predetermined wall segment that separates said inflow groove from said outflow groove, said predetermined wall segment including an edge adjacent said inflow groove;
- and
- a spool within said bore for movement along said longitudinal center line, said spool including a land, said land being opposed to said predetermined wall segment and in sliding fit to said predetermined wall segment during movement of said spool to close a clearance between said land and said predetermined wall segment,
- said land being formed with a plurality of transfer passages bounded within said land, each of said plurality of transfer passages being in the form of a groove that extends along said longitudinal center line,
- said land being opposed to said predetermined wall segment and in sliding fit to said predetermined wall segment to close a clearance between said land and said predetermined wall segment during movement of said spool relative to said valve body over substantially all stroke allowed for said spool to move along said longitudinal center line,
- each of said plurality of transfer passages being open to said outflow groove over substantially all stroke allowed for said spool to move along said longitudinal center line,
- said plurality of transfer passages being separated from each other, each of said plurality of transfer passages having one end wall and other end wall and extending along said center line from said one end wall to said other end wall, each of said plurality of transfer passages having a predetermined section extending from said one end wall to a point between said one end wall and said other end wall,
- said predetermined section of each transfer passage being opposed to said predetermined wall segment and prevented from communication with said inflow groove when said spool assumes a predetermined position relative to said valve body,
- said predetermined section of each transfer passage being brought into opposed relation to said inflow groove gradually as said spool moves from said predetermined position within the stroke allowed for said spool to move along said center line relative to said valve body,
- said edge of said predetermined wall segment and said predetermined section defining various flow cross sectional areas as said spool moves from said predetermined position within the stroke allowed for said spool to move along said center line relative to said valve body.
10 more elements
Dependencies are inferred from the claim text.