Method of operating a spark ignition engine

Claim 1

A method for operating an internal combustion spark ignition engine at substantially minimum lean misfire limit LMFL wherein said engine comprises at least one cylinder and a reciprocating piston therein defining a main combustion chamber, a cylindrical shaped auxiliary combustion chamber associated with said main combustion chamber, an orifice positioned in the forward end of said cylindrical shaped combustion chamber and providing communication between said main combustion chamber and said cylindrical shaped auxiliary combustion chamber, and spark ignition means positioned in the rearward 50 percent of said cylindrical shaped auxiliary combustion chamber as measured from said orifice providing an initial ignition point to effect ignition of a fuel-air mixture in said cylindrical shaped auxiliary combustion chamber, said method comprising, in combination: providing said main combustion chamber with said cylindrical shaped auxiliary combustion chamber wherein said cylindrical shaped auxiliary combustion chamber is defined as having a predetermined length over diameter ratio L/D within the range of 1 to about 9; introducing a fuel-rich mixture of fuel and air having a fuel content of at least about 200 percent of stoichiometric PCSF into said cylindrical shaped auxiliary combustion chamber as said fuel-air mixture therein in an amount P which is at least about 125 volume percent of the volume of said cylindrical shaped auxiliary combustion chamber, with said fuel content and said amount of said fuel-rich mixture both being predetermined relative to said length over diameter ratio; introducing a fuel-lean mixture of fuel and air into said main combustion chamber; and igniting said fuel-rich mixture at said initial ignition point located as predetermined relative to said length over diameter L/D ratio, thereby effecting ignition of said fuel-lean mixture in said main combustion chamber via said orifice; and selecting said L/D ratio, said PCSF, said initial ignition point location, and said amount P, in combination substantially in accordance with the relationship limits defined by the curves of FIGS. 5, 6, 7, and 8, the selection being effective in combination to operate said engine at said substantially LMFL.

Claim 2

A method for operating an internal combustion spark ignition engine at substantially minimum lean misfire limit LMFL wherein said engine comprises at least one cylinder and a reciprocating piston therein defining a main combustion chamber, a cylindrical shaped auxiliary combustion chamber associated with said main combustion chamber, an orifice positioned in the forward end of said cylindrical shaped combustion chamber and providing communication between said main combustion chamber and said cylindrical shaped auxiliary combustion chamber, and spark ignition means positioned in the rearward 50 percent of said cylindrical shaped auxiliary combustion chamber as measured from said orifice providing an initial ignition point to effect ignition of a fuel-air mixture in said cylindrical shaped auxiliary combustion chamber, said method comprising, in combination: providing said main combustion chamber with said cylindrical shaped auxiliary combustion chamber wherein said cylindrical shaped auxiliary combustion chamber is defined as having a predetermined length over diameter ratio L/D within the range of 1 to about 9; introducing a fuel-rich mixture of fuel and air having a fuel content of at least about 200 percent of stoichiometric PCSF into said cylindrical shaped auxiliary combustion chamber as said fuel-air mixture therein in an amount P which is at least about 125 volume percent of the volume of said cylindrical shaped auxiliary combustion chamber, with said fuel content and said amount of said fuel-rich mixture both being predetermined relative to said length over diameter ratio; introducing a fuel-lean mixture of fuel and air into said main combustion chamber; and igniting said fuel-rich mixture at said initial ignition point located as predetermined relative to said length over diameter L/D ratio, thereby effecting ignition of said fuel-lean mixture in said main combustion chamber via said orifice; and selecting said L/D ratio, said PCSF, said initial ignition point location, and said amount P, in combination substantially in accordance with the relationship limits defined by the curves of FIGS. 5, 6, 7, and 8, the selection being effective in combination to operate said engine at said substantially LMFL.

Claim 17

A method for operating an internal combustion spark ignition engine at substantially minimum lean misfire limit LMFL wherein said engine comprises at least one cylinder with a reciprocating piston therein defining a main combustion chamber, a cylindrical shaped auxiliary combustion chamber associated with said main combustion chamber and in open communication therewith by means of an orifice positioned in the forward end of said cylindrical shaped combustion chamber and providing said communication between said main combustion chamber and said cylindrical shaped auxiliary combustion chamber, and spark ignition means positioned in the rearward 50 percent of said cylindrical shaped auxiliary combustion chamber as measured from said orifice providing an initial ignition point to effect ignition of a fuel-air mixture in said cylindrical shaped auxiliary combustion chamber, said method comprising, in combination: providing said main combustion chamber with said cylindrical shaped auxiliary combustion chamber wherein said cylindrical shaped auxiliary combustion chamber is defined as having a predetermined length over diameter ratio L/D within the range of 1 to about 9; introducing a fuel-rich mixture of fuel and air having a fuel content of at least about 200 percent of stoichiometric PCSF into said cylindrical shaped auxiliary combustion chamber as said fuel-air mixture therein in an amount P which is at least about 125 volume percent of the volume of said cylindrical shaped auxiliary combustion chamber, with said fuel content and said amount of said fuel-rich mixture both being predetermined relative to said length over diameter ratio; introducing a fuel-lean mixture of fuel and air into said main combustion chamber; and igniting said fuel-rich mixture at said initial ignition point located as predetermined relative to said length over diameter L/D ratio, thereby effecting ignition of said fuel-lean mixture in said main combustion chamber via said orifice; wherein said L/D ratio, said PCSF, said initial ignition point, and said amount P, are controlled in combination substantially in accordance with the relationship limits defined by the curves of FIGS. 5, 6, 7, and 8, thereby operating said engine at said substantially LMFL with minimal emissions of pollutants.

Claim 18

A method for operating an internal combustion spark ignition engine at substantially minimum lean misfire limit LMFL wherein said engine comprises at least one cylinder with a reciprocating piston therein defining a main combustion chamber, a cylindrical shaped auxiliary combustion chamber associated with said main combustion chamber and in open communication therewith by means of an orifice positioned in the forward end of said cylindrical shaped combustion chamber and providing said communication between said main combustion chamber and said cylindrical shaped auxiliary combustion chamber, and spark ignition means positioned in the rearward 50 percent of said cylindrical shaped auxiliary combustion chamber as measured from said orifice providing an initial ignition point to effect ignition of a fuel-air mixture in said cylindrical shaped auxiliary combustion chamber, said method comprising, in combination: providing said main combustion chamber with said cylindrical shaped auxiliary combustion chamber wherein said cylindrical shaped auxiliary combustion chamber is defined as having a predetermined length over diameter ratio L/D within the range of 1 to about 9; introducing a fuel-rich mixture of fuel and air having a fuel content of at least about 200 percent of stoichiometric PCSF into said cylindrical shaped auxiliary combustion chamber as said fuel-air mixture therein in an amount P which is at least about 125 volume percent of the volume of said cylindrical shaped auxiliary combustion chamber, with said fuel content and said amount of said fuel-rich mixture both being predetermined relative to said length over diameter ratio; introducing a fuel-lean mixture of fuel and air into said main combustion chamber; and igniting said fuel-rich mixture at said initial ignition point located as predetermined relative to said length over diameter L/D ratio, thereby effecting ignition of said fuel-lean mixture in said main combustion chamber via said orifice; wherein said L/D ratio, said PCSF, said initial ignition point, and said amount P, are controlled in combination substantially in accordance with the relationship limits defined by the curves of FIGS. 5, 6, 7, and 8, thereby operating said engine at said substantially LMFL with minimal emissions of pollutants.