Engine system

An engine control method for use with an engine system including an engine body including an intake passage through which intake air entering the engine body flows, an exhaust passage through which exhaust gas exiting the engine body flows, an adjustment apparatus which adjusts an engine output parameter, a catalytic exhaust gas purification apparatus that is disposed in the exhaust passage and purifies exhaust gas, an exhaust gas recirculation (EGR) passage that connects the exhaust passage on a downstream side relative to the catalytic exhaust gas purification apparatus with the intake passage and returns EGR gas as part of exhaust gas to the intake passage, an EGR valve that opens and closes the EGR passage, an outside air temperature acquisition apparatus that acquires an outside air temperature, controller that controls the adjustment apparatus and the EGR valve, the method comprising:

• acquiring a purification apparatus temperature as a temperature of the catalytic exhaust gas purification apparatus,
• carrying out, via the controller, restriction control to control the adjustment apparatus that adjust an engine output parameter of an engine such that an upper limit value of the engine output parameter is set lower than a maximum value and the engine output parameter has a value equal to or lower than the upper limit value in a case where a purification apparatus temperature is lower than a predetermined reference temperature, wherein the adjustment apparatus includes a fuel injector, a throttle valve, an intake valve operating mechanism, and/or exhaust valve operating mechanism,
• setting the upper limit value to a first upper limit value when the outside air temperature acquired by the outside air temperature acquisition apparatus is at a first temperature and a second upper limit value when the outside air temperature is at a second temperature that is higher than the first temperature, the first upper limit value being lower than the second upper limit value, and
• prohibiting opening of the EGR valve when the outside air temperature is lower than a predetermined reference temperature.

An engine system for a hybrid vehicle, the engine system comprising:

• an internal combustion engine body configured to produce engine output that charges a battery for a motor that propels the hybrid vehicle;
• an intake passage through which intake air entering the engine body flows;
• an exhaust passage through which exhaust gas exiting the engine body flows;
• an adjustment apparatus which adjusts an engine output parameter, the adjustment apparatus including a fuel injector, a throttle valve, intake valve operating mechanism, and/or exhaust valve operating mechanism and the engine output parameter including engine torque and/or engine crankshaft rotation speed;
• a catalytic exhaust gas purification apparatus which is disposed in the exhaust passage and purifies exhaust gas;
• an exhaust gas recirculation (EGR) passage which connects the exhaust passage on a downstream side relative to the catalytic exhaust gas purification apparatus with the intake passage and returns EGR gas as part of exhaust gas to the intake passage;
• an EGR valve which opens and closes the EGR passage;
• an outside air temperature acquisition apparatus which acquires an outside air temperature;
• and
• a controller which controls the adjustment apparatus and the EGR valve, wherein the controller:
• acquires a purification apparatus temperature as a temperature of the catalytic exhaust gas purification apparatus;
• carries out restriction control to control the adjustment apparatus such that an upper limit value of the engine output parameter is set lower than a maximum value and the engine output parameter has a value equal to or lower than the upper limit value in a case where the purification apparatus temperature is lower than a predetermined reference temperature, and
• sets the upper limit value to a first upper limit value when the outside air temperature acquired by the outside air temperature acquisition apparatus is at a first temperature and a second upper limit value when the outside air temperature is at a second temperature that is higher than the first temperature, the first upper limit value being lower than the second upper limit value, wherein
• the controller prohibits opening of the EGR valve when the outside air temperature is lower than a predetermined reference temperature.