Method and apparatus for the control of valve operations in internal combustion engine

Abstract

An apparatus and a method for controlling the operation of intake and exhaust valves of an internal combustion engine having a plurality of intake and exhaust valves for each cylinder to provide an optimum engine output at all operating speeds. When the engine is rotating at a low speed, a part of both of the intake and exhaust valves are rendered inoperative. When the engine is rotating at a medium speed, all of the intake valves are made operative and a part of the exhaust valves are rendered inoperative. Finally, when the engine is rotating at a high speed, all of both of the intake and exhaust valves are rendered operative.

We claim: 
     
       1. A method for operating the valves of an internal combustion engine having a plurality of cylinders and a plurality of intake valves and a plurality of exhaust valves for each cylinder of said engine, comprising the steps of: for a low speed of rotation of said engine, placing a part of each of said intake valves and said exhaust valves out of operation;   for a medium speed of rotation of said engine, placing all of said intake valves in operation and a part of said exhaust valves in operation; and   for a high speed of rotation of said engine, placing all intake and exhaust valves in operation.   
     
     
       2. An apparatus for controlling the valves of an internal combustion engine having a plurality of intake valves and a plurality of exhaust valves for each cylinder of said engine, comprising: means for sensing a rotational speed of said engine; and   means, operating in response to said speed sensing means, for placing a part of said intake and a part of said exhaust valves out of operation when said sensing indicates said engine is rotating at a low speed, placing all of said intake valves in operation and a part of said exhaust valves out of operation when said engine is rotating at a medium speed, and placing all of said intake and exhaust valves in operation when said engine is rotating at a high speed.   
     
     
       3. The valve control apparatus of claim 2, wherein said second-recited means comprises: means for selectively mechanically linking so as to operate together intake valves of each said cylinder and means for selectively mechanically linking so as to operate together exhaust valves of each said cylinder. 
     
     
       4. The valve control apparatus of claim 3, wherein said means for selectively mechanically linking comprises: a piston slidably disposed in a cylindrical passage formed in a rocker arm of one of each pairs of selectively mechanically linkable valves, and a spring-loaded guide pin mounted in a rocker arm of the other one of each of said pairs of valves opposing said piston, said piston being slidable into a cylindrical passage in which said guide pin is disposed in response to application of a pressure to a side thereof opposite said guide pin. 
     
     
       5. The valve control apparatus of claim 4, wherein said second-recited means further comprises: a plurality of control valves for selectively supplying a hydraulic fluid under pressure to said pistons. 
     
     
       6. The valve control apparatus of any one of claims 1 through 4, wherein said internal combustion engine has four cylinders, each of said cylinders having two intake valves and two exhaust valves, and wherein said second-recited means places two of said intake valves and two of said exhaust valves out of operation when said engine is rotating at said low speed and places two of said exhaust valves out of operation when said engine is rotating at said medium speed. .Iadd. 
     
     
       7.  A method of operating the valves of an internal combustion engine having a plurality of cylinders and a plurality of intake valves and a plurality of exhaust valves for each cylinder of said engine, comprising the steps of: for a low speed rotation of said engine, placing a part of each of said intake valves and said exhaust valves in a first mode of operation and another part of each of said intake valves and said exhaust valves in a second mode of operation different from the first mode of operation, the first mode of operation allowing both the intake and exhaust of more gases through the intake valves and exhaust valves, respectively, than the second mode of operation;   for medium speed rotation of said engine, placing all said intake valves in the said first mode of operation and part of said exhaust valves in the first mode of operation and part of said exhaust valves in the second mode of operation; and   for high speed rotation of said engine, placing all said intake valves and exhaust valves in the first mode of operation..Iaddend. .Iadd.8. A method of operating the valves of an internal combustion engine having a plurality of cylinders and a plurality of intake valves and a plurality of exhaust valves, comprising the steps of:   for a high speed rotation of said engine, operating all of the intake and exhaust valves to a fully open condition for producing a first effective total cross-sectional area of valve opening of maximum magnitude for all the intake and exhaust valves;   for a medium speed rotation of said engine, operating the intake and exhaust valves for producing a second effective total cross-sectional area of valve opening of at least the exhaust valves of less than said first effective total cross-sectional area for the exhaust valves; and   for a lower speed rotation of said engine, operating the intake and exhaust valves for producing a third effective total cross-sectional area at valve opening less than said second total cross-sectional area..Iaddend. .Iadd.9. A method of operating the valves of an internal combustion engine having a plurality of cylinders and plurality of intake valves and a plurality of exhaust valves, comprising the steps of:   for a high speed rotation of said engine, operating all of the intake valves and exhaust valves to a fully open condition for producing a maximum inertial effect in the intake gases and exhaust gases and maximizing the engine output at high speed rotation;   for a medium speed rotation of said engine, operating the intake and exhaust valves to a condition for producing a reduced inertial effect in the exhaust gases for restricting the recirculation of exhaust gases into the intake gases while maintaining a high inertial effect in the intake gases for maintaining a high level of fuel-air mixture intake gases into the cylinders for maximizing engine output at medium speed rotation; and   for a lower speed rotation of said engine, operating the intake and exhaust valves to a condition for producing a reduced inertial effect in both the intake gases and exhaust gases for restricting the recirculation of exhaust gases into the intake gases and reducing the fuel-air mixture intake gases into the cylinders for maximizing the engine output at lower   
     
     
        speed rotation..Iaddend. .Iadd.10.  An apparatus for controlling the valves of an internal combustion engine having a plurality of intake valves and a plurality of exhaust valves, comprising: means for sensing a rotational speed of said engine,   first hydraulically operated means for modifying the opening operation of at least some of said intake valves,   second hydraulically operated means for modifying the opening operation of at least some of said exhaust valves,   control means operating in response to said speed sensing means for separately and selectively actuating said first hydraulically operated means and said second hydraulically operated means for providing increasing totals of cross-sectional area of valve openings for increasing engine rotational speeds for increasing the engine power output at said speeds..Iaddend. .Iadd.11. The apparatus of claim 10 wherein said control means operates to provide three different totals of cross-sectional area of valve openings, namely, smallest total area, intermediate total area and largest total area for low speed, medium speed and high speed engine operation, respectively..Iaddend. .Iadd.12. The apparatus of claim 11 wherein said intermediate total area comprises a maximum total area of intake valve openings and a less than maximum total area of exhaust valve openings..Iaddend.