Electro-hydraulic valve train

摘要

An electro-hydraulic valve train is configured to change valve lift and valve opening/closing timing according to operation state of an engine. The electro-hydraulic valve train includes a valve stem having a valve head formed at a lower end thereof and a big-diameter stem formed at a middle portion thereof, the big-diameter stem having a larger diameter than the other portion, a swing arm having a roller contacting with a cam of a camshaft and an end connected to the valve stem, the one end being adapted to pivot with respect to the other end according to a rotation of the cam so as to move the valve stem upwardly or downwardly, a first brake unit enclosing the valve stem and adapted to perform brake operation in a case that the valve stem moves upwardly, and a second brake unit mounted at the other end of the swing arm and adapted to selectively move the other end of the swing arm upwardly or downwardly and to perform brake operation in a case that the other end of the swing arm moves downwardly.

主权项

1. An electro-hydraulic valve train, comprising:
a brake piston having a small-diameter portion formed at an upper portion of the brake piston and a big-diameter portion having a smaller diameter than the small-diameter portion and formed at a lower portion of the brake piston; a valve stem having a valve head formed at a lower end thereof and an upper end portion coupled with the brake piston; a swing arm having a roller contacting with a cam of a camshaft, and a first end coupled to an upper end of the brake piston, the first end of the swing arm being adapted to pivot with respect to a second end of the swing arm according to a rotation of the cam to move the valve stem and the brake piston upwardly or downwardly; a first brake unit enclosing the small-diameter portion and the big-diameter portion of the brake piston and adapted to perform brake operation when the brake piston moves upwardly; and a second brake unit mounted at the second end of the swing arm and adapted to selectively move the second end of the swing arm upwardly or downwardly and to perform brake operation when the second end of the swing arm moves downwardly.