Control device for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10006380-B2
Application number	US-201214411974-A
Country	US
Kind code	B2
Filing date	Jul 6, 2012
Priority date	Jul 6, 2012
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

An object of this invention is, in an internal combustion engine having of in-cylinder direct injection and port injection, to enable the early elimination of a difference between fuel concentrations of fuel injected from different injection valves that can arise when a mixing ratio of different kinds of fuel contained in the fuel that is used changes significantly. To achieve this, the control device of this invention normally controls a fuel injection amount of each injection valve in accordance with the operating state of the internal combustion engine, while a change arose in the mixing ratio of different kinds of fuel contained in the fuel that is used or while there is a possibility for such a change, the control device controls a fuel injection amount of each injection valve so that fuel is temporarily injected from both the in-cylinder injection valve and the port injection valve.

First claim

The invention claimed is:

1. An internal combustion engine, comprising:
a cylinder;
an intake port;
an in-cylinder injection valve which injects fuel directly into the cylinder;
a port injection valve which injects fuel into the intake port;
a fuel tank which stores fuel in which different kinds of fuel are mixed;
a fuel supply system which supplies fuel from the fuel tank to the in-cylinder injection valve and the port injection valve, and
an engine control computer programmed to:
control a fuel injection amount of the in-cylinder injection valve and a fuel injection amount of the port injection valve in accordance with an operating state of the internal combustion engine; and
detect at least one of a change in a mixing ratio of different kinds of fuel contained in a fuel that is used and a possibility of the change; and
only when a change in the mixing ratio of different kinds of fuel contained in the fuel that is used is detected, control a fuel injection amount of the in-cylinder injection valve and a fuel injection amount of the port injection valve so that fuel is injected from both of the in-cylinder injection valve and the port injection valve.

2. The internal combustion engine according to claim 1 , wherein the engine control computer detects a change in the mixing ratio of different kinds of fuel contained in the fuel that is used based on a change in an output value of a concentration sensor that corresponds to a specific fuel component.

3. The internal combustion engine according to claim 1 , wherein the engine control computer detects at least one of a fact that refueling of fuel into a fuel tank was performed and a fact that refueling of fuel into the fuel tank will be performed as a possibility of a change in a concentration of a fuel component in a fuel that is used.

4. The internal combustion engine according to claim 1 , wherein the engine control computer detects at least one of a fact that the internal combustion engine was started and a fact that the internal combustion engine will be started as a possibility of a change in the mixing ratio of different kinds of fuel contained in the fuel that is used.

5. The internal combustion engine according to claim 2 , wherein the concentration sensor is disposed at a position that is before a branch point at which a fuel supply line extending from a discharge port of a fuel pump branches into a first fuel supply line that is connected to the in-cylinder injection valve and a second fuel supply line that is connected to the port injection valve.

6. The internal combustion engine according to claim 2 , wherein the concentration sensor is integrated with a fuel pump and disposed inside the fuel tank.

7. The internal combustion engine according to claim 1 , wherein the engine control computer determines an ignition timing and a fuel injection amount based on a mixing ratio of different kinds of fuel that is estimated based on an output value of a concentration sensor provided in the fuel supply system.

8. The internal combustion engine according to claim 1 , wherein the engine control computer, at a normal time when a change in the mixing ratio of different kinds of fuel contained in the fuel that is used or a possibility of the change is not detected, determines an ignition timing and a fuel injection amount based on a mixing ratio of different kinds of fuel that is calculated based on a feedback correction amount relating to air-fuel ratio feedback control, and in a case where at least one of a change in the mixing ratio of different kinds of fuel contained in the fuel that is used and a possibility of the change is detected, determines an ignition timing and a fuel injection amount based on a range of the mixing ratio of different kinds of fuel that is estimated based on an output value of a concentration sensor.

9. The internal combustion engine according to claim 1 , wherein, after detecting at least one of a change in the mixing ratio of different kinds of fuel contained in the fuel that is used and a possibility of the change, upon confirming that a mixing ratio of different kinds of fuel contained in fuel injected from the in-cylinder injection valve and a mixing ratio of different kinds of fuel contained in fuel injected from the port injection valve both change to become mixing ratios that are approximately equal to each other, the engine control computer controls a fuel injection amount of the in-cylinder injection valve and a fuel injection amount of the port injection valve based on a ratio that is in accordance with the operating state of the internal combustion engine.

10. The internal combustion engine according to claim 9 , wherein the engine control computer confirms that the mixing ratio of different kinds of fuel contained in fuel that is injected from the in-cylinder injection valve and the mixing ratio of different kinds of fuel contained in fuel that is injected from the port injection valve both change to become mixing ratios that are approximately equal to each other by determining whether or not an amount of change in an output value of an air-fuel ratio sensor when a ratio between a fuel injection amount of the in-cylinder injection valve and a fuel injection amount of the port injection valve was changed to a ratio that is equal to or greater than a predetermined ratio or an amount of change in a parameter that is calculated based on the output value is less than a threshold value.

11. The control device for an internal combustion engine according to claim 1 , wherein the fuel is a fuel in which an alcohol and a hydrocarbon-based fuel are mixed.

Assignees

• Wakao Kazuhiro
• Kato Mie
• Tsukagoshi Takahiro
• Matsuda Kazuhisa
• Toyota Motor Co Ltd

Inventors

• Wakao Kazuhiro
• Kato Mie
• Tsukagoshi Takahiro
• Matsuda Kazuhisa

Classifications

• F02D19/084

  Blends of gasoline and alcohols, e.g. E85 · CPC title

• F02D19/061

  by controlling fuel injectors · 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

• F02D19/0692

  Arrangement of multiple injectors per combustion chamber · CPC title

• F02D19/08

  simultaneously using pluralities of fuels (F02D19/12 takes precedence) · CPC title