Valve control device for internal combustion engine
AssigneeUnisia Jecs Corporation
InventorsYosihiko Yamada, Seinosuke Hara
Life of this patent
Estimating the term…
Abstract
An improved control device for intake and/or exhaust valves of an internal combustion engine includes a small circumference portion defined in a drive shaft at a location corresponding to that of an annular member which is eccentrically displaced for changing a rotational phase of the cams. According to this a degree of displacement of the annular member may be increased and control the cams, and thereby the engine valves, may be enhanced. Further, the cam lobe of each cam is formed such that side portions thereof are asymmetrical with respect to a center line of the cam for favorably affecting valve opening and closing timings. In addition, an improved lubricating arrangement for enhancing smooth operation and improved engine performance.
Claims25
In an internal combustion engine having a drive shaft, and a plurality of cams formed about a cam shaft for operating intake and exhaust valves,
- a control device comprising:
- a first flange provided on said cam shaft, said first flange having a first elongate slit which extends radially;
- a second flange facing said first flange with a certain clearance therebetween and being secured to said drive shaft to rotate therewith, said second flange having a second elongate slit which extends radially;
- an annular member rotatably disposed within said clearance, said drive shaft being disposed through a central opening of said annular member with a given clearance therebetween;
- first and second pins disposed on opposed sides of said annular member respectively, said first and second pins being provided on opposing sides of said annular member and disposed at diametrically opposed positions with respect to a center of said annular member and slidably engaged with said first and second elongate slits respectively;
- and
- drive means for pivoting said annular member about a pivot axis eccentric to said axis of said drive shaft in accordance with an operating condition of said engine;
- lubricating means providing lubricating fluid to a vicinity of said engagement between said first and second pins and said first and second elongate slits;
- wherein said drive shaft has a reduced circumference portion formed therein at a position at which said drive shaft passes through said central opening of said annular member;
- and
- wherein a profile of a cam provided on said cam shaft is formed such that lift and closing sides of said cam are asymmetrical with respect to center line thereof.
In an internal combustion engine having a drive shaft, and a plurality of cams formed about a cam shaft for operating intake and exhaust valves,
- a control device comprising:
- a first flange provided on said cam shaft, said first flange having a first elongate slit which extends radially;
- a second flange facing said first flange with a certain clearance therebetween and being secured to said drive shaft to rotate therewith, said second flange having a second elongate slit which extends radially;
- an annular member rotatably disposed within said clearance, said drive shaft being disposed through a central opening of said annular member with a given clearance therebetween;
- first and second pins disposed on opposed sides of said annular member respectively, said first and second pins being provided on opposing sides of said annular member and disposed at diametrically opposed positions with respect to a center of said annular member and slidably engaged with said first and second elongate slits respectively;
- and
- drive means for pivoting said annular member about a pivot axis eccentric to said axis of said drive shaft in accordance with an operating condition of said engine;
- wherein said drive shaft has a reduced circumference portion formed therein at a position at which said drive shaft passes through said central opening of said annular member.
In an internal combustion engine having a drive shaft, and a plurality of cams formed about a cam shaft for operating intake and exhaust valves,
- a control device comprising:
- a first flange provided on said cam shaft, said first flange having a first elongate slit which extends radially;
- a second flange facing said first flange with a certain clearance therebetween and being secured to said drive shaft to rotate therewith, said second flange having a second elongate slit which extends radially;
- an annular member rotatably disposed within said clearance, said drive shaft being disposed through a central opening of said annular member with a given clearance therebetween;
- first and second pins disposed on opposed sides of said annular member respectively, said first and second pins being provided on opposing sides of said annular member and disposed at diametrically opposed positions with respect to a center of said annular member and slidably engaged with said first and second elongate slits respectively;
- and
- drive means for pivoting said annular member about a pivot axis eccentric to said axis of said drive shaft in accordance with an operating condition of said engine;
- wherein a profile of a cam provided on said cam shaft is formed such that lift and closing sides of said cam are asymmetrical with respect to a center line thereof.
Dependencies are inferred from the claim text.