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US 7,461,620 B2Granted
Variable valve actuation device of internal combustion engine
AssigneeHitachi, Ltd.
InventorSeinosuke Hara
Life of this patent
Estimating the term…
Abstract
A valve actuating link is provided for transmitting a combined movement of a drive cam on a cam shaft and a control cam on a control shaft to a valve pressing structure of an engine valve. The valve actuating link comprises a bearing portion that bears the control shaft, a hook-shaped lower portion that surrounds the cam shaft keeping a given space therebetween and a cam portion that repeatedly pushes the valve pressing structure to induce an open/close operation of the engine valve. Each of a plurality of engine valves has its own respective drive cam, control cam, valve actuating link and valve pressing structure.
Claims28
A variable valve actuating device of an internal combustion engine, comprising:
- a cam shaft driven by a crankshaft of the engine, the cam shaft having drive cams formed thereabout, each drive cam associated with and actuating a respective one of a plurality of engine valves;
- a control shaft having control cams formed thereabout, each control cam associated with a respective one of said plurality of engine valves, the control shaft changing angular position about its longitudinal axis in accordance with an operating condition of the engine;
- a plurality of valve actuating links, each valve actuating link associated with a respective one of said plurality of engine valves and having a bearing portion that bears against the control shaft so as to be swingable about the axis of the control shaft and a cam portion that is movable in a space defined between the cam shaft and a valve pressing structure of the respective engine valve to engage the valve pressing structure and induce an open/close operation of the respective engine valve when the valve actuating link is swung about the axis of the control shaft;
- a plurality of swing arms, each swing arm associated with a respective one of said plurality of engine valves and pivoted to the respective valve actuating link, a first end of the swing arm contacting the respective drive cam and a second end of the swing arm contacting the respective control cam;
- and
- a plurality of biasing members, each biasing member associated with a respective one of said plurality of engine valves, biasing the first end of the respective swing arm toward the respective drive cam and biasing the second end of the respective swing arm toward the respective control cam,
- whereby a change in the angular position of the control shaft changes the angular position of the control cams, which varies the degree of lift of said plurality of engine valves.
4 more elements
A variable valve actuating device of an internal combustion engine, comprising:
- a cam shaft driven by a crankshaft of the engine, the cam shaft having drive cams formed thereabout, each drive cam associated with and actuating a respective one of a plurality of engine valves;
- a plurality of valve actuating links, each valve actuating link associated with a respective one of said plurality of engine valves and having a cam portion that is swingably movable in a space defined between the cam shaft and a valve pressing structure of the respective engine valve to engage the valve pressing structure and induce an open/close operation of the respective engine valve, the cam portion being swingable about a first imaginary axis which is located at a position opposite to the engine valve with respect to the cam shaft;
- and
- a lift degree varying mechanism that transmits torque from the drive cams to the valve actuating links to rock the valve actuating links, and varies the traveling paths of the valve actuating links to vary the valve lift degree of the engine valves, the lift degree varying mechanism including a plurality of swing arms, each swing arm associated with a respective engine valve and swung by the respective drive cam to induce the swinging movement of the cam portion of the respective valve actuating link.
1 more element
A variable valve actuating device of an internal combustion engine, comprising:
- a cam shaft driven by a crankshaft of the engine, the cam shaft having drive cams formed thereabout, each drive cam associated with and actuating a respective one of a plurality of engine valves;
- a plurality of valve actuating links, each valve actuating link associated with a respective one of said plurality of engine valves and having a hook-shaped lower portion that extends around and is spaced from the cam shaft, the hook-shaped lower portion having a cam portion that is swingably movable in a space defined between the cam shaft and a valve pressing structure of the respective engine valve to engage the valve pressing structure and induce an open/close operation of the respective engine valve;
- and
- a lift degree varying mechanism that transmits torque from the drive cams to the valve actuating links to rock the valve actuating links, and varies the traveling paths of the valve actuating links to vary the valve lift degree of the engine valves, the lift degree varying mechanism including a plurality of swing arms, each swing arm associated with a respective engine valve and swung by the respective drive cam to induce the swinging movement of the cam portion of the respective valve actuating link.
1 more element
Dependencies are inferred from the claim text.