Controller for internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016290254-A1
Application number	US-201615017194-A
Country	US
Kind code	A1
Filing date	Feb 5, 2016
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

There is provided a controller for an internal combustion engine that includes an exhaust gas recirculation device. The exhaust gas recirculation device includes an exhaust gas recirculation passage, which connects a portion of the intake passage located at a downstream side of the throttle valve with an exhaust passage, a recirculation valve, which opens and closes the exhaust gas recirculation passage, and an actuator, which drives and opens the recirculation valve. The controller includes a processor configured to execute a fuel cut-off process that stops fuel injection from the fuel injection valve, to open the recirculation valve when the fuel cut-off process is executed, and to execute a pressure increase process that increases pressure of the portion of the intake passage at the downstream side of the throttle valve before opening the recirculation valve.

First claim

1 . A controller for an internal combustion engine, wherein the internal combustion engine includes a throttle valve that adjusts a cross-sectional area of an intake passage, an exhaust gas recirculation device, and a fuel injection valve that injects fuel supplied to the internal combustion engine, the exhaust gas recirculation device includes an exhaust gas recirculation passage, which connects a portion of the intake passage located at a downstream side of the throttle valve with an exhaust passage, a recirculation valve, which opens and closes the exhaust gas recirculation passage and is configured to open when moved against pressure from the exhaust passage, and an actuator, which drives and opens the recirculation valve, the controller comprising a processor configured to:
execute a fuel cut-off process that stops fuel injection from the fuel injection valve; open the recirculation valve when the fuel cut-off process is executed; and execute a pressure increase process that increases pressure of the portion of the intake passage at the downstream side of the throttle valve before opening the recirculation valve.

2 . The controller according to claim 1 , wherein the processor is configured to increase an open degree of the throttle valve before opening the recirculation valve.

3 . The controller according to claim 2 , wherein
the internal combustion engine includes a variable valve characteristic mechanism that allows a characteristic of an intake valve to be variable, and the processor is configured to operate the variable valve characteristic mechanism to decrease an amount of air drawn into a combustion chamber of the internal combustion engine under the condition that a pressure in the intake passage is a given value, before opening the recirculation valve.

4 . The controller according to claim 3 , wherein the processor is configured to
set a target value of the amount of air drawn into the combustion chamber when the fuel cut-off process is executed, and operate the throttle valve to obtain the target value of the amount of air.

5 . The controller according to claim 4 , wherein the processor is configured to operate the throttle valve based on the target value and the characteristic of the intake valve.

6 . The controller according to claim 3 , wherein the processor is configured to gradually change the characteristic of the intake valve to a predetermined characteristic that decreases the amount of air drawn into the combustion chamber under the condition that a pressure in the intake passage is a given value, before opening the recirculation valve.

7 . The controller according to claim 1 , wherein the processor is configured to diagnose the exhaust gas recirculation device and determine whether or not the exhaust gas recirculation device includes an abnormality based on whether or not fluid flows from the exhaust gas recirculation passage into the intake passage when opening the recirculation valve during execution of the fuel cut-off process.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nozaki Tomohiro

Classifications

• F02D41/0055

  Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus · CPC title

• F02M26/20

  Feeding recirculated exhaust gases directly into the combustion chambers or into the intake runners · CPC title

• F02D11/105

  characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque · CPC title

• F02D41/0002 Primary

  Controlling intake air · CPC title

• F02M26/21

  with EGR valves located at or near the connection to the intake system · CPC title