Lean-burn variable compression ratio engine
OwnerEdward Charles Mendlerinventor
Life of this patent
Estimating the term…
Abstract
The efficiency of a spark-ignition internal-combustion engine having an adjustable fuel-to-air mixture ratio is improved significantly by reducing the fuel-to-air mixture ratio and increasing compression ratio. The increase in compression ratio and the reduction in fuel-to-air mixture ratio causes the engine to operate at higher efficiency and with lower air pollution levels, and without detrimental engine knock or misfire.
Claims35
A method of improving the fuel economy and reducing the tailpipe emissions of spark-ignition internal-combustion engines having a displacement volume, a combustion chamber volume, means for adjusting the compression ratio comprising an adjustment mechanism to vary the combustion chamber volume, an intake and exhaust valve overlap period, and a fuel to air equivalence ratio,
- a first engine setting having a first compression ratio position, a first valve overlap period, and a first fuel to air equivalence ratio, wherein the engine has an adjustable fuel to air equivalence ratio, and the first compression ratio position is below the knock limit of the engine at the first engine setting, having the steps of,
- increasing the compression ratio from the first position to a second position, and reducing the fuel to air equivalence ratio from the first ratio to a second ratio,
- whereby increasing the compression ratio from the first ratio to the second ratio, and reducing the to fuel to air equivalence ratio from the first ratio to the second ratio prevents detrimental engine knock and increases engine efficiency.
In an internal-combustion engine having at least one piston, a displacement volume, a combustion chamber volume, means for adjusting the compression ratio comprising an adjustment mechanism to vary the combustion chamber volume, an intake and exhaust valve overlap period, a bulk mixed gas to fuel ratio having an air-to-fuel ratio, means for adjusting the bulk mixed gas to fuel ratio, and a first engine setting having a first bulk mixed gas to fuel ratio and a first compression ratio, a method of operating the engine at an elevated compression ratio and at an elevated bulk mixed gas to fuel ratio, to improve the fuel efficiency of the engine while avoiding detonation and misfire, comprising the steps of:
- increasing the compression ratio above the knock limit of the first engine setting to extend the stable combustion limit, and
- increasing the bulk mixed gas to fuel ratio to extend the knock limit, and prevent engine knock.
A method of rapidly adjusting the power output of spark-ignition internal-combustion engines having a displacement volume, a combustion chamber volume, means for adjusting the compression ratio comprising an adjustment mechanism to vary the combustion chamber volume, and a bulk mixed gas to fuel ratio having a first setting, including the steps of,
- Increasing the compression ratio to a value greater than 13 to provide an extended lean flammability limit,
- adjusting the bulk mixed gas to fuel ratio from the first setting to a second setting to adjust engine power output, and
- maintaining the compression ratio at a value greater than 13,
- wherein increasing the compression ratio to a value greater than 13 increases the lean flammability limit, adjusting the bulk mixed gas to fuel ratio varies engine power, and maintaining the compression ratio at a value greater than 13 reduces power consumed by the variable compression ratio mechanism during adjustment of compression ratio.
A high-efficiency low-emission vehicle having a curb weight less than 6500 pounds comprising:
- a body;
- and
- a reciprocating piston four-stroke spark-ignition internal combustion engine connected to said body to provide power for moving the vehicle, said engine having a displacement volume, a combustion chamber volume, means for adjusting the compression ratio comprising an adjustment mechanism to vary the combustion chamber volume, an intake and exhaust valve overlap period, and a bulk mixed gas to fuel ratio having an air-to-fuel ratio,
- said vehicle having a California State Low Emission Vehicle II oxides of nitrogen emission test value,
- wherein the engine has means for adjusting the bulk mixed gas to fuel ratio, and
- a first engine setting having a compression ratio less than 12.5, and a second engine setting, having a compression ratio greater than 13, and
- the bulk mixed gas to fuel ratio at the second engine setting is greater than the bulk mixed gas to fuel ratio at the first engine setting,
- wherein the vehicle has a California State Low Emission Vehicle II oxides of nitrogen emission test value less than 0.05 grams per mile.
Dependencies are inferred from the claim text.