Gasoline direct-injection engine

Patent metadata

Field	Value
Publication number	US-9546617-B2
Application number	US-201414548185-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Nov 27, 2013
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A gasoline direct-injection engine is provided. The engine causes a self-ignition of a fuel injected into a cylinder by an injector and at least containing gasoline. The engine includes a controller for controlling the fuel injection by the injector. A geometric compression ratio of the engine is 15:1 or higher. The controller causes the injector to perform a pre-injection for keeping a variation of an in-cylinder temperature after a compression top dead center within a predetermined temperature range by injecting an amount of the fuel that causes an oxidative reaction without resulting in a hot flame reaction. The controller causes the injector to perform a main injection for causing self-ignition combustion of the fuel after the compression top dead center while the variation of the in-cylinder temperature is kept within the predetermined temperature range, by injecting the fuel after the pre-injection.

First claim

What is claimed is:

1. A gasoline direct-injection engine for causing a self-ignition of a fuel injected into a cylinder by an injector and at least containing gasoline, comprising:
a controller for controlling a fuel injection by the injector,
wherein a geometric compression ratio of the engine is 15:1 or higher;
wherein the controller causes the injector to perform a pre-injection for keeping a variation of an in-cylinder temperature after a compression top dead center within a predetermined temperature range by injecting an amount of the fuel that causes an oxidative reaction without resulting in a hot flame reaction;
wherein the controller causes the injector to perform a main injection for causing self-ignition combustion of the fuel after the compression top dead center and while the variation of the in-cylinder temperature is kept within the predetermined temperature range, by injecting the fuel after the pre-injection;
wherein the pre-injection is at least divided into a first pre-injection and a second pre-injection for injecting the fuel after the first pre-injection;
wherein the first pre-injection is performed in an early stage of a compression stroke, and the second pre-injection is performed in an early stage of an expansion stroke before the main injection; and
wherein the self-ignition is caused when an engine load reaches or exceeds a predetermined threshold value in a high load range.

2. The engine of claim 1 , wherein the predetermined temperature range is 100 degrees Kelvin in width.

3. The engine of claim 2 , wherein the in-cylinder temperature is between 1,000K and 1,100K while the variation of the in-cylinder temperature is kept within the predetermined temperature range.

4. The engine of claim 1 , wherein an in-cylinder pressure is reduced to be lower than an in-cylinder pressure at the compression top dead center while the variation of the in-cylinder temperature is kept within the predetermined temperature range.

5. The engine of claim 4 , further comprising an ozone generator for generating ozone within the cylinder,
wherein the controller causes the ozone generator to generate ozone after the main injection.

6. The engine of claim 1 , wherein in the pre-injection, the fuel is injected by an amount with which an air excess ratio becomes 8 or higher.

7. The engine of claim 6 , wherein with respect to a total injection amount of the fuel including the pre-injection and the main injection, a ratio of the injection amount of the fuel injected in the main injection is ¾ or higher.

8. The engine of claim 1 , wherein the controller advances the combustion caused by the main injection, as an engine speed increases.

9. The engine of claim 1 , further comprising an ozone generator for generating ozone within the cylinder,
wherein the controller causes the ozone generator to generate ozone after the main injection.

10. A gasoline direct-injection engine for causing a self-ignition of a fuel injected into a cylinder by an injector and at least containing gasoline, comprising:
a controller for controlling a fuel injection by the injector,
wherein a geometric compression ratio of the engine is 15:1 or higher;
wherein the controller causes the injector to perform a pre-injection for keeping a variation of an in-cylinder temperature after a compression top dead center within a predetermined temperature range by injecting an amount of the fuel that causes an oxidative reaction without resulting in a hot flame reaction;
wherein the controller causes the injector to perform a main injection for causing self-ignition combustion of the fuel after the compression top dead center and while the variation of the in-cylinder temperature is kept within the predetermined temperature range, by injecting the fuel after the pre-injection;
wherein the pre-injection is at least divided into a first pre-injection and a second pre-injection for injecting the fuel after the first pre-injection;
wherein the first pre-injection is performed in an early stage of a compression stroke, and the second pre-injection is performed in an early stage of an expansion stroke before the main injection;
wherein the self-ignition is caused when an engine load reaches or exceeds a predetermined threshold value in a high load range;
wherein the in-cylinder temperature is between 1,000K and 1,100K while the variation of the in-cylinder temperature is kept within the predetermined temperature range; and
wherein with respect to a total injection amount of the fuel including the pre-injection and the main injection, a ratio of the injection amount of the fuel injected in the main injection is ¾ or higher.

Assignees

• Mazda Motor

Inventors

• Fujimoto Masahiko
• Takahashi Yoshitomo
• Koga Yoshiyuki
• Yamashita Hiroyuki

Classifications

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02M27/04

  by electric means, {ionisation, polarisation} or magnetism · CPC title

• Y02T10/142

  Cross-Sectional Technologies · mapped topic

• F02F3/10

  having surface coverings (F02F3/02 takes precedence) · CPC title

• F02M25/12

  the apparatus having means for generating such gases (using rays and simultaneously generating ozone F02M27/06) · CPC title