Multi-cylinder internal combustion engine
AssigneeNissan Motor Co., Ltd.
InventorsKenji Masaki, Kenji Okamura
Life of this patent
Estimating the term…
Abstract
At relatively low afterburner temperatures cylinders of an engine are separately fed with rich and lean mixtures, while at high speeds and excessive high afterburner temperatures the cylinders are fed with only the lean mixture.
Claims14
A multi-cylinder internal combustion engine having a first group of cylinders and a second group of cylinders, the engine being followed by an after-burner to purifying exhaust gases discharged from the first and second groups of cylinders, said engine comprising:
- a carburetor for supplying into the first and second groups of cylinders a first air-fuel mixture whoch is leaner than the stoichiometric air fuel mixture;
- a mixture enriching device arranged to supply supplemental fuel from the fuel chamber of said carburetor into portions upstream of the intake ports of said second group of cylinders to enrich the first air-fuel mixture into a second air-fuel mixture which is richer than the stoichiometric air-fuel mixture;
- and
- control means to cause said mixture enriching device to stop supply of the supplemental fuel during at least one of high engine speed, high engine load, and excessively high afterburner temperature.
A multi-cylinder internal combustion engine as claimed in c;laim 4, in which said engine temperature sensor senses engine coolant temperature.
A multi-cylinder internal combustion engine having a first group of cylinders and a second group of cylinders, the engine being followed by an afterburner to purify exhaust gases discharged from the first and second groups of cylinders, said engine comprising:
- a carburetor for supplying into the first and second groups of cylinders a first air-fuel mixture having an air-fuel ratio ranging from 17:1 to 20:1, said carburetor including a supplemental fuel jet communicating with the fuel chamber of the carburetor, a feed passage communicating the fuel jet with the air-fuel mixture induction passage of said carburetor, a supplemental air bleed orifice communicating with the feed passage, and a chamber disposed in the feed passage and having a first opening which communicates with the supplemental fuel jet, and a second opening which communicates with the air-fuel mixture induction passage of said carburetor;
- a feed tube communicating the feed passage of said carburetor downstream of said chamber with portions upstream of the intake ports of the second group of cylinders, the supplemental fuel jet and the supplemental air bleed orifice being selected to supply supplemental fuel from the fuel chamber of said carburetor through the feed passage and said feed tube in a manner to enrich the first air-fuel mixture into a second air-fuel mixture having an air-fuel ratio ranging from 10:1 to 14:1;
- a normally open solenoid valve disposed with said carburetor, the valve member of said solenoid valve being arranged to close the second opening of the feed chamber of said carburetor in response to an electric signal transmitted thereto;
- at least one sensor which senses at least one parameter of engine speed, engine load and afterburner temperature;
- a control circuit electrically connected between said normally open solenoid valve and said at least one sensor, said control circuit being arranged to generate an electric signal and transmit it to said normally open solenoid valve when the at least one parameter of engine speed, engine load and afterburner temperature exceeds its predetermined level.
Dependencies are inferred from the claim text.