Internal combustion engine control method and control device

Patent metadata

Field	Value
Publication number	US-11686268-B2
Application number	US-201917613610-A
Country	US
Kind code	B2
Filing date	May 24, 2019
Priority date	May 24, 2019
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

A control method of an internal combustion engine including an in-cylinder injection fuel injection valve arranged to inject a fuel to a combustion chamber, and a port injection fuel injection valve arranged to inject the fuel to an intake port, the control method includes: sensing or estimating a fuel temperature at a tip end portion of the in-cylinder injection fuel injection valve; sensing an intake pressure; judging whether or not a flash boiling condition based on the fuel temperature and the intake pressure; setting the in-cylinder fuel injection valve to a default fuel injection valve; and injecting an entire or a part of the fuel from the port injection fuel injection valve by decreasing an injection amount ratio of the in-cylinder injection fuel injection valve when the flash boiling condition is satisfied.

First claim

The invention claimed is:

1. A control method of an internal combustion engine including an in-cylinder injection fuel injection valve arranged to inject a fuel to a combustion chamber, and a port injection fuel injection valve arranged to inject the fuel to an intake port, the control method comprising:
sensing or estimating a fuel temperature at a tip end portion of the in-cylinder injection fuel injection valve;
sensing an intake pressure;
judging whether or not a flash boiling condition in which a flash boiling condition may be generated is satisfied, based on the fuel temperature and the intake pressure;
setting the in-cylinder fuel injection valve to a default fuel injection valve; and
injecting an entire or a part of the fuel from the port injection fuel injection valve by decreasing an injection amount ratio of the in-cylinder injection fuel injection valve when the flash boiling condition is satisfied.

2. The control method of the internal combustion engine as claimed in claim 1 , wherein a flash boiling lower limit temperature and a flash boiling upper limit temperature are previously set in accordance with the intake pressure; and
when the sensed or estimated fuel temperature is between the flash boiling lower limit temperature and the flash boiling upper limit temperature which correspond to the sensed intake pressure, it is judged that the flash boiling condition is satisfied.

3. The control method of the internal combustion engine as claimed in claim 2 , wherein an intake valve temperature is sensed or estimated; and
when the intake valve temperature exceeds an intake valve threshold temperature by which a generation of a fluid film due to the fuel injected from the port injection fuel injection valve is avoided, and when the fuel temperature does not exceed the flash boiling upper limit temperature, the entire or the part of the fuel is injected from the port injection fuel injection valve by decreasing the injection amount ratio of the in-cylinder injection fuel injection valve, irrespective of the flash boiling condition.

4. The control method of the internal combustion engine as claimed in claim 3 , wherein when the fuel injection valve exceeds the flash boiling upper limit temperature, the injection amount ratio of the in-cylinder injection fuel injection valve is increased.

5. The control method of the internal combustion engine as claimed in claim 1 , wherein the fuel temperature is estimated by using at least one of a water cooling temperature, a fuel injection amount, an engine speed, an engine load, and an air fuel ratio which relate to the fuel temperature at the tip end portion of the in-cylinder injection fuel injection valve.

6. A control device of an internal combustion engine including an in-cylinder injection fuel injection valve arranged to inject a fuel to a combustion chamber, and a port injection fuel injection valve arranged to inject the fuel to an intake port, the in-cylinder injection fuel injection valve being a default fuel injection valve, the control device comprising:
the control device being configured
to variably control an injection amount ratio of the in-cylinder injection fuel injection valve, and an injection amount ratio of the port injection fuel injection valve in accordance with a condition,
to sense or estimate a fuel temperature at a tip end portion of the in-cylinder injection fuel injection valve, and
to sense an intake pressure, and

when it is judged that a flash boiling condition in which a flash boiling may be generated is satisfied, based on the fuel temperature and the intake pressure, the control device being configured to decrease the injection amount ratio of the in-cylinder injection fuel injection valve, and to increase the injection amount ratio of the port injection fuel injection valve.

Assignees

• Nissan Motor

Inventors

• Sakata Tomohiro
• Sugano Taiichiro

Classifications

• F02D41/047

  Taking into account fuel evaporation or wall wetting; (special correction after fuel cut-off F02D41/126) · CPC title

• F02D2250/00

  Engine control related to specific problems or objectives · CPC title

• F02D2200/0606

  Fuel temperature · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title

• F02D2200/101

  Engine speed · CPC title