Control device for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10774803-B2
Application number	US-201916275332-A
Country	US
Kind code	B2
Filing date	Feb 14, 2019
Priority date	Mar 12, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A control device for an internal combustion engine which is provided with an engine body, a water injector for injecting water to the inside of an intake passage of the engine body, and a fuel injector for injecting fuel to be made to burn inside a combustion chamber of the engine body. The control device is provided with a water injection control part controlling the amount of injection of water from the water injector in the combustion cycle where fuel is injected from the fuel injector so that water vaporizing inside the intake passage during the suction stroke and water vaporizing inside the combustion chamber during the compression stroke are generated.

First claim

The invention claimed is:

1. A control device for an internal combustion engine,
the internal combustion engine comprising:
an engine body;
a water injector for injecting water inside of an intake passage of the engine body; and
a fuel injector for injecting fuel made to burn inside a combustion chamber of the engine body, wherein

the control device comprises a water injection control part configured to control an amount of injection of water from the water injector in a combustion cycle where fuel is injected from the fuel injector so that water which vaporizes inside the intake passage during the suction stroke and water which vaporizes inside the combustion chamber during the compression stroke are formed,
the water injection control part is configured to control the amount of injection of water from the water injector so that the amount of injection of water from the water injector becomes a total of the amount of water which vaporizes inside the intake passage, defined as the intake passage vaporization amount, and the amount of water which vaporizes inside the combustion chamber in the compression stroke after flowing into the combustion chamber, defined as the combustion chamber vaporization amount,
the control device further comprises:
an ignition timing control part configured so as to control an ignition timing of a spark plug for igniting fuel inside the combustion chamber based on the engine operating state; and
an ignition timing correction part configured so as to correct the ignition timing to the advanced side based on the amount of injection of water from the water injector, and

the ignition timing correction part is configured so as to:
calculate the first ignition timing correction amount based on the combustion chamber vaporization amount,
calculate the second ignition timing correction amount based on the intake passage vaporization amount, and
correct the ignition timing to the advanced side based on the total of the first ignition timing correction amount and the second ignition timing correction amount.

2. The control device according to claim 1 , wherein
the water injection control part is configured to:
calculate the maximum amount of water able to be made to vaporize inside the combustion chamber during the compression stroke, defined as the maximum vaporization amount, based on a saturated steam amount inside the combustion chamber as determined according to the state inside the combustion chamber during the compression stroke,
calculate the estimated amount of water able to be made to actually vaporize inside the combustion chamber during the compression stroke, defined as the vaporizable amount, based on the maximum vaporization amount and the vaporization time of water inside the combustion chamber as changing according to the engine rotational speed, and
control the amount of injection of water from the water injector using the vaporizable amount as the total amount.

3. The control device according to claim 2 , wherein
the water injection control part is configured to:
calculate the maximum amount of water able to be made to vaporize inside the intake passage, defined as the maximum intake passage vaporization amount, based on the amount of saturated steam inside the intake passage as determined according to the state inside the intake passage,
calculate the intake passage vaporization amount based on the maximum intake passage vaporization amount and the vaporization time of water inside the intake passage as changing according to the engine rotational speed, and
calculate the combustion chamber vaporization amount based on the vaporizable amount and the intake passage vaporization amount.

Assignees

• Toyota Motor Co Ltd

Inventors

• Okada Yoshihiro

Classifications

• F02D19/12

  peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel · CPC title

• F02B47/02 Primary

  the substances being water or steam · CPC title

• F02D37/02

  one of the functions being ignition · CPC title

• F02M25/028

  into the charge intakes · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title