Charge forming device with fuel vaporization

Claim 2

In an internal combustion engine of the stratified charge type having one or more cylinders, each cylinder including a main chamber, a pre-chamber communicating with the main chamber for igniting a charge in said main chamber, and a fuel supply system having a main chamber fuel means for supplying fuel and air to the main chamber as a function of engine load and a pre-chamber fuel means for feeding fuel to the pre-chamber as an inverse function of engine load, the fuel supply system comprising: an intake passage for receiving fuel and air prior to combustion in said main chamber; an exhaust passage in close proximity to said intake passage for accepting exhaust gases from said main chamber and characterized by higher pressures than those of said intake passage; wall means directly separating said intake passage from said exhaust passage; fuel line means communicating with a fuel source means for transporting fuel from said fuel source means; a fuel pump for continuously maintaining a fuel supply pressure substantially constant with respect to engine crank angle and above air supply pressure to supply fuel directly from said fuel source means to said fuel line means; and a cross-over tube penetrating said wall means and communicating at a first end with said intake passage and communicating at a second end with said exhaust passage for permitting a flow of exhaust gases from said exhaust passage directly to said intake passage, said cross-over tube forming a junction with said fuel line means to thereby form a single conduit means from said fuel source means to said intake passage, whereby said crossover tube receives fuel from said fuel line means and permits such fuel to mix with said exhaust gases within said cross-over tube for vaporization by heat transferred from said exhaust gases.

Claim 3

An internal combustion engine fuel system as defined in claim 1 wherein said junction comprises means joining said second end of said cross-over tube with said fuel line means within said exhaust passage, and means forming openings communicating with said cross-over tube within said exhaust passage for admitting said flow of hot exhaust gases from said exhaust passage into said cross-over tube.

Claim 4

An internal combustion engine fuel system as defined in claim 2 wherein said cross-over tube circumscribes and overlaps an end of said fuel line means within said exhaust passage for defining said opening forming means.

Claim 5

An internal combustion engine fuel system as defined in claim 3 further comprising constriction means formed at said junction for admitting sufficient exhaust gases to vaporize all fuel introduced into said cross-over tube and simultaneously damping load induced pressure drop variations across said cross-over tube and thereby damping variations in the rate of said flow of exhaust gases through said cross-over tube, whereby the flow rates of both fuel and exhaust gases through said cross-over tube are related to each other as a function of engine load to establish a temperature level in said cross-over tube, said temperature level being subject only to variations damped around a predetermined temperature level.

Claim 6

An internal combustion engine fuel system as defined in claim 1 wherein said junction between said fuel line means and said cross-over tube is located within said wall means at a point between said exhaust passage and said intake passage.

Claim 7

An internal combustion engine fuel system as defined in claim 5 further comprising constriction means for admitting sufficient exhaust gases to vaporize fuel introduced into said cross-over tube and simultaneously damping load induced pressure drop variations across said cross-over tube and thereby damping variations in the rate of said flow of exhaust gases through said cross-over tube, whereby the flow rates of both fuel and exhaust gases through said cross-over tube are related to each other as a function of engine load to establish a temperature level in said cross-over tube, said temperature level being subject only to variations damped around a predetermined temperature level.

Claim 8

An internal combustion engine fuel system as defined in claim 1 further comprising constriction means formed in said cross-over tube for passing sufficient exhaust gases to produce vaporization of substantially all fuel introduced into said cross-over tube and simultaneously damping load induced pressure drop variations across said cross-over tube to damp variations in the rate of said flow of exhaust gases through said wall means, whereby the flow rates of both fuel and exhaust gases through said cross-over tube are related to each other as a function of engine load to establish a temperature level in said cross-over tube, said temperature level being subject only to variations damped around a predetermined temperature level.

Claim 9

In an internal combustion engine of the stratified charge type having one or more cylinders, each including a main chamber, a pre-chamber communicating with the main chamber for igniting a charge in said main chamber, and a fuel supply system having a main chamber fuel means for supplying fuel and air to the main chamber as a function of engine load and a pre-chamber fuel means for feeding fuel to the pre-chamber as an inverse function of engine load, a method of vaporizing fuel prior to combustion in said main chamber comprising the steps of: introducing primary exhaust gases from said main chamber into an exhaust passage at a temperature varying as an increasing function of engine load; pumping fuel from a fuel supply source into a fuel line means as an increasing function of engine load; introducing said fuel in a trickle into a continuously open cross-over tube penetrating a wall means separating an intake passage from said exhaust passage as an increasing function of engine load; maintaining a higher characteristic pressure in said exhaust passage than in said intake passage, thereby inducing a flow of exhaust gases from said exhasut passage through said cross-over tube into said intake passage, said pressure differential varying as an increasing function of engine load; mixing said exhaust gases with said fuel in said cross-over tube; vaporizing said fuel by means of heat transferred from said exhaust gases to said fuel; transporting said fuel and exhaust mixture through said cross-over tube into said intake passage by means of said flow of exhaust gases therethrough; regulating said flow of exhaust gases through said cross-over tube by a passage of a constant predetermined size formed thereby for permitting a sufficient flow therethrough of exhaust gases to vaporize fuel introduced into said cross-over tube and for modulating about a predetermined temperature the temperature variation of said mixture of fuel and exhaust gases; and inducting said mixture of fuel and exhaust gases from said intake passage into said main combustion chamber.

Claim 10

In an internal combustion engine of the stratified charge type having one or more cylinders, each including a main chamber, a pre-chamber communicating with the main chamber for igniting a charge in said main chamber, and a fuel supply system having a main chamber fuel means for supplying fuel and air to the main chamber as a function of engine load and a pre-chamber fuel means for feeding fuel to the pre-chamber as an inverse function of engine load, a method of vaporizing fuel prior to combustion in said main chamber comprising the steps of: introducing primary exhaust gases from said main chamber into an exhaust passage at a temperature varying as an increasing function of engine load; pumping fuel from a fuel supply source into a fuel line means as an increasing function of engine load; introducing said fuel in a trickle into a continuously open cross-over tube penetrating a wall means separating an intake passage from said exhaust passage as an increasing function of engine load; maintaining a higher characteristic pressure in said exhaust passage than in said intake passage, thereby inducing a flow of exhaust gases from said exhasut passage through said cross-over tube into said intake passage, said pressure differential varying as an increasing function of engine load; mixing said exhaust gases with said fuel in said cross-over tube; vaporizing said fuel by means of heat transferred from said exhaust gases to said fuel; transporting said fuel and exhaust mixture through said cross-over tube into said intake passage by means of said flow of exhaust gases therethrough; regulating said flow of exhaust gases through said cross-over tube by a passage of a constant predetermined size formed thereby for permitting a sufficient flow therethrough of exhaust gases to vaporize fuel introduced into said cross-over tube and for modulating about a predetermined temperature the temperature variation of said mixture of fuel and exhaust gases; and inducting said mixture of fuel and exhaust gases from said intake passage into said main combustion chamber.