Control apparatus for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9506412-B2
Application number	US-201114355045-A
Country	US
Kind code	B2
Filing date	Nov 2, 2011
Priority date	Nov 2, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

It is an object of this invention to restrain blow-by gas from reaching a catalyst during fuel cutoff, and protect the catalyst while coping with an increase in oil dilution amount resulting from the use of alcohol fuel, in an internal combustion engine that uses the alcohol fuel. An engine is equipped with a PCV mechanism that introduces blow-by gas in a crankcase into an intake system. Besides, when fuel cutoff is executed with the PCV mechanism in operation, an opening degree of a throttle valve during fuel cutoff is set on the basis of an oil dilution amount in lubricating oil. Thus, the throttle opening degree during fuel cutoff is adjusted in accordance with a generation amount of blow-by gas, so that an intake negative pressure can be appropriately reduced. Accordingly, during fuel cutoff, the amount of blow-by gas that is sucked out from the crankcase due to the intake negative pressure and introduced into the intake system can be held small.

First claim

The invention claimed is:

1. A control apparatus for an internal combustion engine, characterized by comprising:
a throttle valve that is provided in an intake passage of the internal combustion engine to adjust an amount of intake air that is sucked into a cylinder via the intake passage;
a fuel injection valve that injects alcohol fuel into the intake passage and/or the cylinder;
a PCV mechanism that introduces, into the intake passage, evaporative fuel that has evaporated from lubricating oil in a crankcase of the internal combustion engine;
an oil dilution amount estimation unit configured to estimate an oil dilution amount as an amount of fuel that has been mixed with the lubricating oil in the crankcase; and
a fuel cutoff throttle control unit configured to set an opening degree of the throttle valve during fuel cutoff on a basis of the oil dilution amount when fuel cutoff is executed with the PCV mechanism in operation, wherein
the fuel cutoff throttle control unit is configured to increase the opening degree of the throttle valve during fuel cutoff as the oil dilution amount increases.

2. The control apparatus for the internal combustion engine according to claim 1 , further comprising:
a variable valve mechanism that can change valve-opening properties of an intake valve; and
a fuel cutoff intake valve control unit configured to retard a valve-opening timing of the intake valve through a use of the variable valve mechanism as the oil dilution amount increases during fuel cutoff.

Assignees

• Tsukagoshi Takahiro
• Morita Kouji
• Fujiwara Takahiko
• Matsuda Kazuhisa
• Toyota Motor Co Ltd

Inventors

• Tsukagoshi Takahiro
• Morita Kouji
• Fujiwara Takahiko
• Matsuda Kazuhisa

Classifications

• F02D41/0005

  during deceleration · CPC title

• F02D41/003 Primary

  Adding fuel vapours, e.g. drawn from engine fuel reservoir · CPC title

• F01M13/00

  Crankcase ventilating or breathing · CPC title

• F02D2250/08

  Engine blow-by from crankcase chamber · CPC title

• F02M25/06

  adding lubricant vapours · CPC title