EGR controller for internal combustion engine

Patent metadata

Field	Value
Publication number	US-8960169-B2
Application number	US-201213531182-A
Country	US
Kind code	B2
Filing date	Jun 22, 2012
Priority date	Jun 24, 2011
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

When a constant driving voltage is applied to a motor driving an EGR valve so that the EGR opening degree is varied, an angular speed of the EGR valve becomes minimal at a position where the driving torque of the EGR valve becomes maximal. In view of this, while an opening degree of the EGR valve is varied with a constant driving voltage applied to the motor, the EGR opening degree where the angular speed becomes minimal is learned as a full-close position.

First claim

What is claimed is:

1. An exhaust gas recirculation controller for an internal combustion engine, comprising:
an EGR valve controlling an exhaust gas quantity recirculating into an intake pipe, the EGR valve being driven in a direction where an opening degree of the EGR valve is increased and in a direction where the opening degree of the EGR valve is decreased with respect to a full-close position of the EGR valve where a rotating friction of the EGR valve becomes a maximal value;
a driving-torque-information detecting portion for detecting a driving-torque information about a driving torque of the EGR valve; and
a full-close-position learning portion for learning an opening degree of the EGR valve as a full-close position, based on the driving-torque information, where the driving torque of the EGR valve becomes maximal.

2. An exhaust gas recirculation controller for an internal combustion engine according to claim 1 , wherein:
the driving-torque-information detecting portion detects an angular speed of the EGR valve as the driving-torque information; and
the full-close-position learning portion learns the full-close position based on the angular speed of the EGR valve.

3. An exhaust gas recirculation controller for an internal combustion engine according to claim 2 , wherein:
the full-close-position learning portion learns an opening degree of the EGR valve where the angular speed becomes minimal as the full-close position, while the opening degree of the EGR valve is varied with a constant driving voltage supplied to a motor driving the EGR valve.

4. An exhaust gas recirculation controller for an internal combustion engine according to claim 2 , wherein:
the full-close-position learning portion learns the opening degree of the EGR valve of when a derivative value of the angular speed becomes a maximal value as the full-close position, while the opening degree of the EGR valve is varied with a constant driving voltage applied to a motor driving the EGR valve.

5. An exhaust gas recirculation controller for an internal combustion engine according to claim 2 , wherein:
the full-close-position learning portion learns an average value of the opening degree of the EGR valve of when a derivative value of the angular speed becomes a maximal value and the opening degree of the EGR valve of when the derivative value of the angular speed becomes a minimal value as the full-close position, while the opening degree of the EGR valve is varied with a constant driving voltage supplied to a motor driving the EGR valve.

6. An exhaust gas recirculation controller for an internal combustion engine according to claim 1 , wherein:
the driving-torque-information detecting portion detects a driving current applied to a motor driving the EGR valve as the driving-torque information; and
the full-close-position learning portion learns the full-close position based on the driving current.

7. An exhaust gas recirculation controller for an internal combustion engine according to claim 6 , wherein:
the full-close-position learning portion learns the opening degree of the EGR valve of when the driving current becomes maximal as the full-close position, while the opening degree of the EGR valve is varied at a constant speed.

8. An exhaust gas recirculation controller for an internal combustion engine according to claim 6 , wherein:
the full-close-position learning portion learns the opening degree of the EGR valve of when a derivative value of the driving current becomes a minimal value as the full-close position, while the opening degree of the EGR valve is varied at a constant speed.

9. An exhaust gas recirculation controller for an internal combustion engine according to claim 2 , wherein:
the full-close-position learning portion learns an average value of the opening degree of the EGR valve of when a derivative value of the driving current becomes a maximal value and the opening degree of the EGR valve of when the derivative value of the driving current becomes a minimal value as the full-close position, while the opening degree of the EGR valve is varied at a constant speed.

10. An exhaust gas recirculation controller for an internal combustion engine according to claim 1 , wherein:
when a learning value of the full-close position learned based on the driving-torque information is within a specified range of a movable range of the EGR valve, the full-close-position learning portion employs the learning value of the full-close position.

Assignees

• Takezoe Hiroyuki
• Nogami Hiroki
• Ichihara Hideaki
• Katsurahara Hiroshi
• Denso Corp

Inventors

• Takezoe Hiroyuki
• Nogami Hiroki
• Ichihara Hideaki
• Katsurahara Hiroshi

Classifications

• F02D2250/16

  End position calibration, i.e. calculation or measurement of actuator end positions, e.g. for throttle or its driving actuator · CPC title

• F02M25/0727

  Mechanical Engineering · mapped topic

• F02M25/0773

  Mechanical Engineering · mapped topic

• F02D2200/1012

  Engine speed gradient · CPC title

• F02D9/02

  concerning induction conduits (throttle valves, or arrangements thereof in conduits F02D9/08) · CPC title