Variable valve lift/timing mechanism

A valve train for an internal combustion engine of the type having a body means defining a cylinder with a port, said valve train including a valve with an axial extending valve stem located for axial movement in said port and normally biased to a predetermined position;

• a valve actuator spaced from said valve and operable to effect reciprocation of said valve;
• a rocker arm having a first end and an opposite second end, said first end thereof engaging said valve actuator;
• said body means including a fixed overhead support means extending over said rocker arm and spaced therefrom a predetermined distance;
• a lash adjuster including a plunger means operatively positioned in said overhead support means with said plunger means having an outboard pivot end means projecting toward said valve stem in substantial coaxial alignment therewith, a pivotable eccentric means operatively located in spaced apart relationship to said valve actuator, a reaction member having a first end and an opposite second end, said first end of said reaction member being pivotably supported at one end by said eccentric means, the said opposite second end of said reaction member pivotably engaging said valve stem and said opposite second end of said rocker arm pivotably engaging said outboard pivot end means of said plunger means;
• and a spring means operatively associated with said rocker arm and with said reaction member to bias said one end of said reaction member into engagement with said eccentric and said one of said rocker arm into engagement with said valve actuator;
• said reaction member and said rocker arm having opposed working surfaces one of which is flat and the other of which has a cam surface contour terminating at spaced apart points, said cam surface contour being in accordance with the following equation ##EQU4## wherein:
• v=maximum valve lift
• c=cam lift
• a=position of cam surface contact with the working surface of the upper reaction member
• = distance between the pivot axis of the valve actuator and said valve stem ralative to the rocker arm connecting one end of the vertical lines representing c and v
• y=height above a straight line extending between the opposite end of the lines representing c and v.

A valve train for an internal combustion engine of the type having a body means defining a cylinder with a port, said valve train including a valve with an axial extending stem located for axial movement in said port and normally biased to a port closed position, a valve actuator spaced from said valve and operable of effect reciprocation of said valve, a rocker arm having a first end and an opposite second end, said first end of said rocker arm engaging said valve actuator, said body means including a fixed overhead support means extending over said rocker arm and spaced thereform a predetermined distance, a lash adjuster oparatively positioned in said overhead support means, said lash adjuster including an axial movable plunger having an outboard end projecting from said overhead support means toward said stem in substantial coaxial alignment with the axis of movement of said valve, a pivotable eccentric means operatively positioned in spaced apart relationship to said valve actuator;

• a reaction member having a first end and a second end with said second end being pivotably supported on said stem with said first end engaging said eccentric means;
• the said opposite end of said rocker arm being pivotably supported by said outboard end of said plunger;
• and a spring means operatively associated with said rocker arm and with said reaction member to bias said opposite end of said reaction member into engegement with said eccentric and to bias said second end of said rocker arm into engagement with said valve actuator;
• said reaction member and said rocker arm having opposed working surfaces one of which is flat and the other of which has a cam surface contour whereby after a predetermined pivotable movement of said rocker arm said opposed working surfaces are in operational contact with each other whereby said working surface of said reaction member can be engaged by said rocker arm whereby to effect pivotable movement of said reaction member to effect opening movement of said valve, the amount of lift and timing thereof of said valve being controlled by the angular position of said eccentric.

A valve train for an internal combustion engine of the type having a body means defining a cylinder with a port, said valve train including a valve with an axial extending valve stem located for axial movement relative to said port and normally biased to a port closed position, a valve actuator spaced from said valve and operable to effect reciprocation of said valve;

• a pivotable eccentric means operatively positioned in spaced apart relationship to said valve actuator;
• said body means including a fixed overhead support means extending over said rocker arm and spaced therefrom a predetermined distance;
• a hydraulic lash adjuster having a plunger means operatively positioned by said overhead support means with said plunger means having an outboard pivot end projecting toward said valve stem in substantial coaxial alignment therewith;
• a rocker arm having one end and an opposite end pivotably supported at said one end by said outboard pivot end of said plunger means and at said opposite end engaging said valve actuator;
• a reaction member pivotably supported at one end on said valve stem with an opposite end thereof being adapted to be engaged by said eccentric means;
• and, a spring means operatively associated with said rocker arm and with said reaction member to bias said opposite end of said reaction member into engagement with said eccentric means and bias said rocker arm into engagement with said valve actuator;
• said rocker arm having a flat working surface and said reaction member having an opposed cam surface contour thereon whereby after a predetermined pivotable movement of said rocker arm said opposed working surfaces are in operational contact with each other whereby said working surface of said reaction member will be engaged by said rocker arm whereby to effect pivotable movement of said reaction member to effect opening movement of said valve, the amount of lift and timing thereof of said valve being controlled by the angular position of said eccentric and thus of said reaction member.