Engine control method and engine control device

Patent metadata

Field	Value
Publication number	US-11028797-B2
Application number	US-201916964508-A
Country	US
Kind code	B2
Filing date	Jan 23, 2019
Priority date	Jan 30, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

The engine control method includes a fuel supply step and an ignition step. In the fuel supply step, the injector supplies fuel into a combustion chamber. In the ignition step, an spark plug arranged in the combustion chamber makes a flame after the supply of the fuel into the combustion chamber and at a timing when a flow strength in the combustion chamber is greater than a predetermined value in a compression stroke during or before a post-mid stage where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, a post-mid stage, and a post-stage.

First claim

The invention claimed is:

1. 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 fuel supply step in which an injector supplies fuel into the combustion chamber; and
an ignition step in which a spark plug arranged in the combustion chamber makes a flame after the supply of the fuel to the combustion chamber and at a timing when a flow strength in the combustion chamber is greater than a predetermined value in the compression stroke 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.

2. The engine control method of claim 1 , wherein
the spark plug makes the flame in the combustion chamber at a timing when a tumble ratio in the combustion chamber is equal to or higher than a predetermined value in the compression stroke.

3. The engine control method of claim 1 , wherein
the spark plug makes the flame in the combustion chamber in the compression stroke with the engine having a speed equal to or higher than a predetermined value.

4. The engine control method of claim 1 , wherein
the injector supplies the fuel in the combustion chamber at a timing when the flame in the combustion chamber is made by the spark plug 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.

5. The engine control method of claim 4 , further comprising:
after the ignition step, a second fuel supply step in which the injector supplies the fuel into the combustion chamber to increase a fuel concentration of an air-fuel mixture in the combustion chamber.

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

7. 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 fuel into the combustion chamber,
the spark plug making a flame after the supply of the fuel into the combustion chamber by the injector and at a timing when a flow strength in the combustion chamber is greater than a predetermined value in the compression stroke 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 device of claim 7 , wherein
the spark plug makes flame in the combustion chamber at a timing when a tumble ratio in the combustion chamber is equal to or higher than a predetermined value in the compression stroke.

9. The engine control device of claim 7 , wherein
the spark plug makes the flame in the combustion chamber in the compression stroke with the engine having a speed equal to or higher than a predetermined value.

10. The engine control device of claim 7 , wherein
the injector supplies the fuel in the combustion chamber at a timing when the spark plug makes the 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.

11. The engine control device of claim 10 , wherein
the injector is configured to supply, after the spark plug has made the flame, the fuel into the combustion chamber to increase a fuel concentration of the air-fuel mixture in the combustion chamber.

12. The engine control device of claim 7 , 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

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D41/402

  Multiple injections · CPC title

• F02P5/1502

  using one central computing unit · CPC title

• F02D41/401

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02M26/06

  Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor · CPC title