Internal combustion engine

Patent metadata

Field	Value
Publication number	US-10767549-B2
Application number	US-201916238794-A
Country	US
Kind code	B2
Filing date	Jan 3, 2019
Priority date	Mar 2, 2018
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

An auxiliary chamber having an auxiliary fuel injector is formed on the top surface of a main combustion chamber. When making the air-fuel mixture inside the auxiliary chamber burn, the air-fuel mixture inside the main combustion chamber is burned by jet flames ejected from a communicating hole. After engine startup and until the elapse of a wall surface lower temperature period where the wall surface temperature of the auxiliary chamber becomes a lower temperature than the wall surface temperature of the auxiliary chamber at the time of completion of warmup, an injection ratio of an injection amount of liquid fuel from the auxiliary fuel injector to a fuel injection amount from a main fuel injector is made to decrease compared with after completion of warmup.

First claim

The invention claimed is:

1. An internal combustion engine comprising:
a main combustion chamber that communicates with an air intake port,
a main fuel injector for feeding fuel to the main combustion chamber,
an auxiliary chamber formed on a top surface of the main combustion chamber and communicating through communicating holes with an inside of the main combustion chamber,
an auxiliary fuel injector arranged in the auxiliary chamber, an air-fuel mixture in the main combustion chamber being burned by jet flames ejected from the communicating holes when liquid fuel injected into the auxiliary chamber is made to burn by an igniter, and
an electronic control unit configured to control an injection ratio of (i) an injection amount of the liquid fuel injected from the auxiliary fuel injector to (ii) an injection amount of the fuel injected from the main fuel injector, the injection ratio being controlled based on a wall surface lower temperature period which is a period during which a wall surface temperature of the auxiliary chamber is lower than the wall surface temperature of the auxiliary chamber at a time of completion of engine warmup, wherein
the electronic control unit is further configured to cause the injection ratio during a first time period to be lower than the injection ratio during a second time period, the first time period extending from a time at which the engine is started to a time at which the wall surface lower temperature period has elapsed, the second time period occurring after the completion of the engine warmup.

2. The internal combustion engine according to claim 1 , wherein the electronic control unit determines that the wail surface lower temperature period has elapsed by determining that the wall surface temperature of the auxiliary chamber has risen to a temperature at which the liquid fuel injected from the auxiliary fuel injector will no longer deposit on an inside wall surface of the auxiliary chamber.

3. The internal combustion engine according to claim 2 , wherein the wall surface temperature of the auxiliary chamber is estimated from an operating state of the engine.

4. The internal combustion engine according to claim 1 , wherein the wall surface lower temperature period is stored in advance in a memory.

5. The internal combustion engine according to claim 1 , wherein the electronic control unit increases an amount by Which the injection ratio is made to decrease in the first time period as an EGR rate increases.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kato Akira

Classifications

• F02B19/00

  Engines characterised by precombustion chambers · CPC title

• F02B19/10

  with fuel introduced partly into pre-combustion chamber, and partly into cylinder · CPC title

• F02D35/025

  by determining temperatures inside the cylinder, e.g. combustion temperatures · CPC title

• F02D41/068

  for warming-up · CPC title

• F02B19/12

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title