Apparatus and method for controlling internal-combustion engine

Patent metadata

Field	Value
Publication number	US-9670863-B2
Application number	US-201313834938-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Jul 24, 2012
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

An apparatus and a method control an internal-combustion engine with a fuel injection valve for injecting fuel into an inlet port. In fuel injection control, injection field pressure at injection start timing is estimated from engine rotation speed and injection starting timing of the fuel injection valve. Since flow rate of the fuel injection valve fluctuates when a fuel accumulating space between a valve body and injection holes of the fuel injection valve changes by injection field pressure, a correction value to correct flow rate fluctuations is calculated based on injection field pressure at injection start timing. Fuel injection by the fuel injection valve is controlled by setting the result of adding the correction value to an injection pulse width calculated from intake air flow, engine rotation speed, etc., to final injection pulse width. Air-fuel ratio error is thereby reduced even when injection field pressure at injection timing changes.

First claim

What is claimed is:

1. An apparatus for controlling an internal-combustion engine, the internal combustion engine including a fuel injection valve that injects a fuel into an inlet port, the fuel injection valve including a fuel accumulating space between a valve body and injection holes thereof, the apparatus comprising:
an injection control unit for controlling an amount of fuel injection through the fuel injection valve by changing a pulse width of an injection pulse signal input to the fuel injection valve, wherein the injection control unit includes:
a first estimating circuit configured to estimate a difference of a pressure within the inlet port with respect to a reference value at an injection starting timing of the fuel injection valve based on a rotation speed of the internal combustion engine and the injection starting timing of the fuel injection valve;
a second estimating circuit configured to estimate whether fuel injection is performed in a state in which fuel vapor is generated at the fuel injection valve, based on the difference; and
a correcting circuit configured to correct the pulse width of the fuel injection pulse signal to be increased when it is estimated that fuel injection is performed in the state in which fuel vapor is generated at the fuel injection valve.

2. The apparatus for controlling an internal-combustion engine according to claim 1 , wherein the first estimating circuit detects a phase and an amplitude of pressure change in the intake port based on the rotation speed of the internal-combustion engine.

3. The apparatus for controlling an internal-combustion engine according to claim 1 , wherein the second estimating circuit estimates whether or not fuel injection is started in the state in which a vapor is generated in a fuel staying in the fuel accumulating space of the fuel injection valve.

4. The apparatus for controlling an internal-combustion engine according to claim 1 , wherein the second estimating circuit estimates whether or not fuel injection is started in the state in which a vapor is generated in a fuel staying upstream the valve body of the fuel injection valve.

5. The apparatus for controlling an internal-combustion engine according to claim 1 , wherein the correcting circuit sets the increase correction value to a smaller value as the injection pulse width is longer.

6. An apparatus for controlling an internal-combustion engine, the internal combustion engine including a fuel injection valve that injects a fuel into an inlet port, the fuel injection valve including a fuel accumulating space between a valve body and injection holes thereof, the apparatus comprising:
injection control means for controlling an amount of fuel injection through the fuel injection valve by changing a pulse width of an injection pulse signal input to the fuel injection valve, wherein the injection control means includes:
first estimating means for estimating a difference of a pressure within the inlet port with respect to a reference value at an injection starting timing of the fuel injection valve based on a rotation speed of the internal combustion engine and the injection starting timing of the fuel injection valve;
second estimating means for estimating whether fuel injection is performed in a state in which fuel vapor is generated at the fuel injection valve, based on the difference; and
correcting means for correcting the pulse width of the fuel injection pulse signal to be increased when it is estimated that fuel injection is performed in the state in which fuel vapor is generated at the fuel injection valve.

7. A method for controlling an internal-combustion engine, the internal combustion engine including a fuel injection valve that injects a fuel into an inlet port, the fuel injection valve including a fuel accumulating space between a valve body and injection holes thereof, the method comprising:
estimating a difference of a pressure within the inlet port with respect to a reference value at an injection starting timing of the fuel injection valve based on a rotation speed of the internal combustion engine and the injection starting timing of the fuel injection valve;
estimating whether fuel injection is performed in a state in which fuel vapor is generated at the injection fuel valve, based on the difference; and
correcting the pulse width of the fuel injection pulse signal to be increased when it is estimated that fuel injection is performed in the state in which fuel vapor is generated at the fuel injection valve.

8. The method for controlling an internal-combustion engine according to claim 7 , wherein the estimating the difference includes: detecting a phase and an amplitude of pressure change in the intake port based on the rotation speed of the internal-combustion engine.

9. The method for controlling an internal-combustion engine according to claim 7 , wherein the estimating whether or not fuel injection is performed in a state in which the fuel vapor is generated includes: estimating whether or not fuel injection is started in the state in which a vapor is generated in a fuel staying in the fuel accumulating space of the fuel injection valve.

10. The method for controlling an internal-combustion engine according to claim 7 , wherein the estimating whether or not fuel injection is performed in a state in which the fuel vapor is generated includes: estimating whether or not fuel injection is started in the state in which a vapor is generated in a fuel staying upstream the valve body of the fuel injection valve.

11. The method for controlling an internal-combustion engine according to claim 7 , wherein the correcting the pulse width to be increased includes setting the increase correction value to a smaller value as the injection pulse width is longer.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Nakamura Yoshitatsu

Classifications

• F02D2200/0602

  Fuel pressure · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• F02B2275/48

  Tumble motion in gas movement in cylinder · CPC title

• F02D41/34 Primary

  with means for controlling injection timing or duration · CPC title

• F02D33/006

  depending on engine operating conditions, e.g. start, stop or ambient conditions · CPC title