Engine control method and engine control device

Patent metadata

Field	Value
Publication number	US-11242812-B2
Application number	US-201916964501-A
Country	US
Kind code	B2
Filing date	Jan 23, 2019
Priority date	Jan 30, 2018
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

An engine control method includes: a first fuel supply step of supplying fuel into the combustion chamber using an injector when a spark plug makes flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio; after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber.

First claim

The invention claimed is:

1. An engine control device comprising:
a combustion chamber of an engine that executes a cycle including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke;
a spark plug arranged in the combustion chamber; and
an injector configured to supply a fuel into the combustion chamber, wherein
the injector supplies the fuel in the combustion chamber at a timing when the spark plug makes a flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio,
the spark plug is configured to make the flame in the combustion chamber at a predetermined timing in the compression stroke;
the injector is configured to supply the fuel into the combustion chamber in the compression stroke to increase a fuel concentration of the air-fuel mixture in the combustion chamber after the spark plug has made the flame; and
a total amount of the fuel supplied into the combustion chamber in the compression stroke from ignition to a start of combustion is smaller than a total amount of the fuel supplied to the combustion chamber before the ignition.

2. The engine control device of claim 1 , wherein
the spark plug makes the flame during or before a post-mid stage, where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, the post-mid stage, and a post-stage.

3. The engine control device of claim 2 , wherein
the spark plug makes the flame at a middle stage, where the compression stroke is divided into three stages of an initial stage, the middle stage, and a final stage.

4. The engine control device of claim 1 , wherein
the injector is configured to supply the fuel into the combustion chamber so that the A/F or G/F of the air-fuel mixture in the combustion chamber is lower than or equal to the stoichiometric air-fuel ratio after the spark plug has made the flame.

5. The engine control device of claim 1 , wherein
the engine has a geometric compression ratio of 14 or more.

6. An engine control method of executing a cycle including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke in a combustion chamber of an engine, the method comprising:
a first fuel supply step for supplying a fuel into the combustion chamber using an injector at a timing when a spark plug makes a flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio;
after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and
after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber, wherein
a total amount of the fuel supplied into the combustion chamber in the compression stroke from ignition to a start of combustion is smaller than a total amount of the fuel supplied to the combustion chamber before the ignition.

7. The engine control method of claim 6 , wherein
the spark plug makes the flame during or before a post-mid stage, where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, the post-mid stage, and a post-stage.

8. The engine control method of claim 7 , wherein
the spark plug makes the flame at a middle stage, where the compression stroke is divided into three stages of an initial stage, the middle stage, and a final stage.

9. The engine control method of claim 6 , wherein
the injector supplies the fuel into the combustion chamber in the second fuel supply step so that the A/F or G/F of the air-fuel mixture in the combustion chamber is lower than or equal to the stoichiometric air-fuel ratio.

10. The engine control method of claim 6 , wherein
the engine has a geometric compression ratio of 14 or more.

11. An engine control method of executing a cycle including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke in a combustion chamber of an engine, the method comprising:
a first fuel supply step for supplying a fuel into the combustion chamber using an injector at a timing when a spark plug makes a flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio;
after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and
after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber, wherein
the injector supplies the fuel into the combustion chamber in the second fuel supply step so that the A/F or G/F of the air-fuel mixture in the combustion chamber is lower than or equal to the stoichiometric air-fuel ratio.

12. The engine control method of claim 11 , wherein the spark plug makes the flame during or before a post-mid stage, where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, the post-mid stage, and a post-stage.

13. The engine control method of claim 12 , wherein the spark plug makes the flame at a middle stage, where the compression stroke is divided into three stages of an initial stage, the middle stage, and a final stage.

14. The engine control method of claim 11 , wherein the engine has a geometric compression ratio of 14 or more.

Assignees

• Mazda Motor

Inventors

• Hitomi Mitsuo
• Nakai Eiji
• Yamaguchi Naohiro
• Morimoto Hiroki

Classifications

• Y02T10/40

  Engine management systems · CPC title

• F02B37/162

  by bypassing, e.g. partially, intake air from pump inlet to pump outlet · CPC title

• F02D41/1454 Primary

  the characteristics being an oxygen content or concentration or the air-fuel ratio · CPC title

• F02P5/1502

  using one central computing unit · CPC title

• F02B2075/027

  four · CPC title