Lost motion assembly for a poppet valve of an internal combustion engine
AssigneeGeneral Motors Corporation
InventorsJie Tong, Burak A. Gecim
Life of this patent
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Abstract
A lost motion assembly for a valve of an internal combustion engine includes a cam, a cam piston which is spring biased to follow motion of the cam, a valve piston operatively engaged with a poppet valve, and an auxiliary piston. The cam piston, valve piston and auxiliary piston are in continuous contact with a fluid in an enclosed control chamber having a fixed volume, such that rotation of the cam causes displacement of the cam piston into the control chamber, which causes a corresponding displacement of at least one of the valve piston and auxiliary piston while the volume of fluid in the control chamber remains substantially constant.
Claims20
An internal combustion engine valve operating system comprising:
- a cam;
- a cam piston which is spring-biased to follow motion of said cam;
- a valve piston operatively engaged with a poppet valve for opening the poppet valve;
- and
- an auxiliary piston movable with respect to an adjustable stop member;
- wherein said cam piston, valve piston and auxiliary piston are in continuous contact with a fluid in an enclosed control chamber having a fixed volume, such that displacement of said cam piston into said control chamber causes movement of said valve piston and/or said auxiliary piston, depending on the adjusted position of said adjustable stop member, while the volume of fluid in said control chamber remains substantially constant.
A lost motion assembly for a poppet valve of an internal combustion engine comprising:
- a cam;
- a cam piston which is spring-biased to follow motion of said cam;
- a valve piston operatively engaged with a poppet valve for opening the poppet valve;
- and
- an auxiliary piston;
- wherein said cam piston, valve piston and auxiliary piston are in continuous contact with a fluid in an enclosed control chamber having a fixed volume, such that rotation of said cam causes displacement of said cam piston into said control chamber, which causes a corresponding displacement of at least one of said valve piston and said auxiliary piston while the volume of fluid in said control chamber remains substantially constant;
- and
- wherein the allowable range of movement of said auxiliary piston is controllable such that the resulting valve lift of said poppet valve may be adjusted between a deactivated condition in which there is lost motion between the cam and the poppet valve, and a fully openable condition in which there is no lost motion.
An internal combustion engine valve operating system comprising:
- a cam;
- a cam piston which is spring-biased to follow motion of said cam;
- a valve piston operatively engaged with a poppet valve for opening the poppet valve;
- an auxiliary piston movable with respect to an adjustable stop member;
- wherein said cam piston, valve piston and auxiliary piston are in continuous contact with a fluid in an enclosed control chamber having a fixed volume, such that displacement of said cam piston into said control chamber causes movement of said valve piston and/or said auxiliary piston, depending on the adjusted position of said adjustable stop member, while the volume of fluid in said control chamber remains substantially constant;
- wherein said control chamber is formed within a housing, and said cam piston, valve piston and auxiliary piston are movably positioned in the housing;
- and
- wherein said adjustable stop member comprises a screw which is threadedly engaged with a holding nut attached to said housing, said screw being attached to a motor which adjusts the position of the screw.
Dependencies are inferred from the claim text.