Control device for internal combustion engine

An apparatus comprising:

• an engine body;
• and
• an exhaust after-treatment system installed in an exhaust passage of the engine body;
• and
• circuitry configured to:
• calculate a temperature of exhaust flowing into the exhaust after-treatment system as a first exhaust temperature;
• calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature;
• calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature;
• and
• judge whether the exhaust after-treatment system is in a removed state removed from the exhaust passage or a normal state not removed from the exhaust passage, when a predetermined condition stands, based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature, wherein
• the predetermined condition includes being in a transition state where the flow rate of intake air of the internal combustion engine becomes a predetermined flow rate or more within a predetermined time from when the flow rate of intake air increases and being the timing at which a predetermined time lag elapses from when a time derivative of the rate of change over time of the first exhaust temperature becomes zero during the transition state.

An apparatus comprising:

• an engine body;
• and
• an exhaust after-treatment system installed in an exhaust passage of the engine body;
• and
• circuitry configured to:
• calculate a temperature of exhaust flowing into the exhaust after-treatment system as a first exhaust temperature;
• calculate a temperature of exhaust flowing out from the exhaust after-treatment system as a second exhaust temperature;
• calculate a rate of change over time of the first exhaust temperature and a rate of change over time of the second exhaust temperature;
• and
• judge a state of attachment of the exhaust after-treatment system to the exhaust passage, when a predetermined condition stands, based on a difference between the rate of change over time of the first exhaust temperature and the rate of change over time of the second exhaust temperature, wherein
• the predetermined condition includes being in a transition state where the flow rate of intake air of the internal combustion engine becomes a predetermined flow rate or more within a predetermined time from when the flow rate of intake air increases and being the timing at which a predetermined time lag elapses from when a time derivative of the rate of change over time of the first exhaust temperature becomes zero during the transition state.