Control system of engine

Patent metadata

Field	Value
Publication number	US-2016245128-A1
Application number	US-201615007468-A
Country	US
Kind code	A1
Filing date	Jan 27, 2016
Priority date	Feb 19, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

A control system of an engine is provided. The control system includes an exhaust variable valve mechanism for changing an operation mode of an exhaust valve, a fuel injection controlling module for controlling a fuel injector to inject fuel at a fuel injection timing associated with an operating state of the engine, a variable valve mechanism controlling module for operating the exhaust valve via the exhaust variable valve mechanism in a first operation mode when the operating state of the engine is within a compression self-ignition range, and in a second operation mode when the operating state of the engine is within a spark-ignition range, and a first in-cylinder state quantity estimating module for estimating a first state quantity inside the cylinder relating to a burned gas amount within the cylinder.

First claim

1 . A control system of an engine where compression self-ignition combustion is performed when an operating state of the engine is within a predetermined compression self-ignition range, and spark-ignition combustion is performed when the operating state of the engine is within a predetermined spark-ignition range, the control system comprising:
an exhaust variable valve mechanism for changing an operation mode of an exhaust valve of the engine; a fuel injection controlling module for controlling a fuel injector of the engine to inject fuel at a fuel injection timing associated with the operating state of the engine; a variable valve mechanism controlling module for operating the exhaust valve via the exhaust variable valve mechanism in a first operation mode when the operating state of the engine is within the compression self-ignition range, and operating the exhaust valve via the exhaust variable valve mechanism in a second operation mode when the operating state of the engine is within the spark-ignition range, the first operation mode being a mode where the exhaust valve is opened on intake stroke to reintroduce burned gas into a cylinder of the engine from an exhaust port of the engine, and the second operation mode being a mode where the exhaust valve is closed at a timing advanced from a closing timing of the exhaust valve in the first operation mode; and a first in-cylinder state quantity estimating module for estimating a first state quantity inside the cylinder relating to a burned gas amount within the cylinder, wherein when the operating state of the engine is switched between the spark-ignition range and the compression self-ignition range, the fuel injection controlling module controls the fuel injection timing based on the first state quantity inside the cylinder.

2 . The control system of claim 1 , wherein when the operating state of the engine is switched from the compression self-ignition range to the spark-ignition range, in a case where the first state quantity inside the cylinder is within a predetermined spark-ignition combustion threshold range where the spark-ignition combustion is performable, the fuel injection controlling module applies a fuel injection timing associated with the spark-ignition combustion, and in a case where the first state quantity inside the cylinder is outside the spark-ignition combustion threshold range, the fuel injection controlling module applies a fuel injection timing associated with stratified spark-ignition combustion that is performed by forming substantially uniform pre-mixture gas inside the cylinder on the intake stroke, then injecting the fuel on compression stroke to form stratified mixture gas around an ignition plug of the engine, and spark-igniting the stratified mixture gas to combust the stratified mixture gas along with the pre-mixture gas.

3 . The control system of claim 1 , wherein when the operating state of the engine is switched from the spark-ignition range to the compression self-ignition range, in a case where the first state quantity inside the cylinder is within a predetermined compression self-ignition combustion threshold range where the compression self-ignition combustion is performable, the fuel injection controlling module applies a fuel injection timing associated with the compression self-ignition combustion, and in a case where the state quantity inside the cylinder is outside the compression self-ignition combustion threshold range, the fuel injection controlling module applies a fuel injection timing associated with stratified spark-ignition combustion that is performed by forming substantially uniform pre-mixture gas inside the cylinder on the intake stroke, then injecting the fuel on compression stroke to form stratified mixture gas around an ignition plug of the engine, and spark-igniting the stratified mixture gas to combust the stratified mixture gas along with the pre-mixture gas.

4 . The control system of claim 1 , further comprising a second in-cylinder state quantity estimating module for estimating a second state quantity inside the cylinder relating to a temperature inside the cylinder,
wherein when the operating state of the engine is switched between the spark-ignition range and the compression self-ignition range, the fuel injection controlling module controls the fuel injection timing based on the first state quantity inside the cylinder estimated by the first in-cylinder state quantity estimating module and the second state quantity inside the cylinder estimated by the second in-cylinder state quantity estimating module.

5 . The control system of claim 1 , wherein the first in-cylinder state quantity estimating module estimates, as the first state quantity inside the cylinder, a ratio of the burned gas amount with respect to a total gas amount introduced into the cylinder.

6 . The control system of claim 2 , wherein when the first state quantity inside the cylinder is outside the spark-ignition combustion threshold range and is within a predetermined compression self-ignition combustion threshold range where the compression self-ignition combustion is performable, the fuel injection controlling module applies a fuel injection timing associated with the compression self-ignition combustion.

7 . The control system of claim 6 , wherein while the fuel injection timing associated with the stratified spark-ignition combustion is applied, when the first state quantity inside the cylinder reaches a value inside the spark-ignition combustion threshold range, the fuel injection controlling module switches the fuel injection timing to the fuel injection timing associated with the spark-ignition combustion.

8 . The control system of claim 6 , wherein when the operating state of the engine is switched from the spark-ignition range to the compression self-ignition range, in a case where the first state quantity inside the cylinder is within the predetermined compression self-ignition combustion threshold range where the compression self-ignition combustion is performable, the fuel injection controlling module applies the fuel injection timing associated with the compression self-ignition combustion, and in a case where the first state quantity inside the cylinder is outside the compression self-ignition combustion threshold range, the fuel injection controlling module applies the fuel injection timing associated with the stratified spark-ignition combustion.

9 . The control system of claim 6 , further comprising a second in-cylinder state quantity estimating module for estimating a second state quantity inside the cylinder relating to a temperature inside the cylinder,
wherein when the operating state of the engine is switched between the spark-ignition range and the compression self-ignition range, the fuel injection controlling module controls the fuel injection timing based on the first state quantity inside the cylinder estimated by the first in-cylinder state quantity estimating module and the second state quantity inside the cylinder estimated by the second in-cylinder state quantity estimating module.

10 . The control system of claim 6 , wherein the first in-cylinder state quantity estimating module estimates, as the first state quantity inside the cylinder, a ratio of the burned gas amount with respect to a total gas amount introduced into the cylinder.

11 . The control system of claim 2 , wherein while the fuel injection timing associated with the stratified spark-ignition combustion is applied, when the first state quantity inside the cylinder reaches a value inside the spark-ignition combustion threshold range, the fuel injection controlling module switches the fuel injection timing to the fuel injection

Assignees

• Mazda Motor

Inventors

• Shintani Shuhei
• Okumura Takuji
• Horiuchi Hiroaki
• Nakagawa Shigeru

Classifications

• F02M57/04

  the devices being combustion-air intake or exhaust valves · CPC title

• F01L1/34 Primary

  characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift} · CPC title

• F02M2026/009

  EGR combined with means to change air/fuel ratio, ignition timing, charge swirl in the cylinder · CPC title

• F02M26/00

  Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems · CPC title

• F02M26/23 Primary

  Layout, e.g. schematics · CPC title