COMPRESSION IGNITION GASOLINE ENGINE

• US 20190309696A1
• Filed: 12/01/2016
• Published: 10/10/2019
• Est. Priority Date: 12/01/2016
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: Youso, Takashi, Kaminaga, Takashi, Yamakawa, Masahisa
• Granted Patent: US 10,837,380 B2
• Time in Patent Office: Days
• CPC Class Codes: F02D 13/02 during engine operation
• CPC Class Codes: F02D 13/0207 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 2001/165 by means dependent on engine load
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/0057 Specific combustion modes combustion modes per se F02D41/3017
• CPC Class Codes: F02D 41/006 using internal EGR control of valve overlap for internal EGR F02D13/0261; arrangements for internal EGR F02M26/01
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode
• CPC Class Codes: F02D 45/00 Electrical control not provided for in groups F02D41/00 - F02D43/00
• CPC Class Codes: F02M 26/01 Internal exhaust gas recirculation, i.e. wherein the residual exhaust gases are trapped in the cylinder or pushed back from the intake or the exhaust manifold into the combustion chamber without the use of additional passages
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A compression ignition gasoline engine includes a fuel injection valve for injecting fuel containing gasoline as a main component into a cylinder; an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; and a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion in which fuel injected from the fuel injection valve self-ignites within the cylinder occurs. The combustion control unit controls the EGR device, in at least a partial load operating range in which HCCI combustion is performed, in such a way that the EGR rate increases, as compared with a low load condition, in a high load condition in which G/F being a ratio between a total amount of gas and a fuel amount within the cylinder decreases.

Claims

1. A compression ignition gasoline engine comprising:

a cylinder for accommodating a piston to be reciprocally movable;

a fuel injection valve for injecting fuel containing gasoline as a main component into the cylinder;

an EGR device operative to perform high-temperature EGR of introducing burnt gas generated in the cylinder into the cylinder at a high temperature; and

a combustion control unit for controlling the fuel injection valve and the EGR device in such a way that HCCI combustion in which fuel injected from the fuel injection valve self-ignites within the cylinder occurs, wherein

the combustion control unit controls the EGR device in such a way that, in at least a partial load operating range in which HCCI combustion is performed, an EGR rate increases, as compared with a low load condition, in a high load condition in which G/F being a ratio between a total amount of gas and a fuel amount within the cylinder decreases.

2. The compression ignition gasoline engine according to claim 1, wherein the combustion control unit controls the EGR device in such a way that an EGR rate at which a coefficient K of an octane index expressed by the following Eq. (1) becomes equal to or larger than a predetermined value is achieved:

OI=(1−

K)×

RON+K×

MON 

 

(1)

where RON denotes a research octane number, and MON denotes a motor octane number.

3. The compression ignition gasoline engine according to claim 1, wherein the combustion control unit controls the EGR device in such a way that an EGR rate at which an ignition timing variation due to a difference in fuel component is suppressed to a predetermined value or smaller is achieved.

4. The compression ignition gasoline engine according to claim 1, wherein

a geometric compression ratio of the cylinder is set to be not smaller than 18 but not larger than 22.

5. The compression ignition gasoline engine according to claim 1, wherein

the EGR device is a valve variable mechanism operative to perform internal EGR of letting burnt gas generated in the cylinder remain in the cylinder, as the high-temperature EGR.