Control apparatus for an internal combustion engine
First Claim
1. A control apparatus for an internal combustion engine comprising:
- a throttle valve that is opened and closed in an intake pipe for adjusting an amount of air supplied to said engine through said intake pipe;
a bypass air amount control section that controls an amount of bypass air flowing while bypassing said throttle valve;
an EGR tube that recirculates an exhaust gas exhausted from said engine into said intake pipe at a location downstream of said throttle valve;
an EGR valve that adjusts a flow rate of EGR of said exhaust gas flowing through said EGR tube;
a sensor part that detects an operating condition of said engine including an intake pipe pressure in said intake pipe and the number of revolutions per minute of said engine;
an EGR control section that controls said EGR valve in accordance with operating condition information from said sensor part;
a failure determination condition detection section that detects, based on said operating condition information, whether a failure determination condition for said EGR control section is satisfied;
an EGR valve forced opening and closing section that forcedly opens and closes said EGR valve based on said operating condition information when said failure determination condition is satisfied; and
a failure determining section that determines whether said EGR control section is in failure, by comparing a pressure change index value based on said intake pipe pressure at the time of the forced opening and closing of said EGR valve with a failure determination value;
wherein said failure determination condition detection section includes an intake pipe pressure adjustment section that adjusts said intake pipe pressure so as to be within a predetermined range by using said bypass air amount control section; and
said failure determination condition detection section detects, as a satisfied state of said failure determination condition, that said intake pipe pressure is within said predetermined range.
1 Assignment
0 Petitions
Accused Products
Abstract
A control apparatus for an internal combustion engine can compensate for a variation of intake pressure resulting from various factors whereby a failure detection area can be expanded, and false detection can be prevented to enable failure determination for an EGR system with high reliability. The apparatus determines whether a vehicle is decelerating, forcedly opens and closes an EGR valve, and determines whether an EGR control device is in failure by comparing a pressure change index value based on intake pressures upon the forced opening and closing of the EGR valve with a failure determination value. The apparatus adjusts the intake pressure to a predetermined state before the EGR valve is forcedly opened and closed, whereby a failure determination can be always made based on the intake pressure whose variation was compensated for with the intake pressure becoming a predetermined characteristic to the number of revolutions per minute of the engine.
36 Citations
7 Claims
-
1. A control apparatus for an internal combustion engine comprising:
-
a throttle valve that is opened and closed in an intake pipe for adjusting an amount of air supplied to said engine through said intake pipe;
a bypass air amount control section that controls an amount of bypass air flowing while bypassing said throttle valve;
an EGR tube that recirculates an exhaust gas exhausted from said engine into said intake pipe at a location downstream of said throttle valve;
an EGR valve that adjusts a flow rate of EGR of said exhaust gas flowing through said EGR tube;
a sensor part that detects an operating condition of said engine including an intake pipe pressure in said intake pipe and the number of revolutions per minute of said engine;
an EGR control section that controls said EGR valve in accordance with operating condition information from said sensor part;
a failure determination condition detection section that detects, based on said operating condition information, whether a failure determination condition for said EGR control section is satisfied;
an EGR valve forced opening and closing section that forcedly opens and closes said EGR valve based on said operating condition information when said failure determination condition is satisfied; and
a failure determining section that determines whether said EGR control section is in failure, by comparing a pressure change index value based on said intake pipe pressure at the time of the forced opening and closing of said EGR valve with a failure determination value;
wherein said failure determination condition detection section includes an intake pipe pressure adjustment section that adjusts said intake pipe pressure so as to be within a predetermined range by using said bypass air amount control section; and
said failure determination condition detection section detects, as a satisfied state of said failure determination condition, that said intake pipe pressure is within said predetermined range. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification