Engine, engine exhaust temperature controlling apparatus, and controlling method

An exhaust system control apparatus for an engine having a plurality of cylinders, comprising:

• a fuel spray valve respectively assigned to each cylinder and controllable to supply a respective amount of fuel to the cylinder;
• a control unit for controlling each valve to supply the respective amount of fuel to the cylinder;
• and
• a respective temperature measuring unit assigned to each cylinder and operable to measure a respective exhaust temperature of the cylinder, each temperature measuring unit outputting a respective exhaust temperature signal to the control unit in accordance with the measured respective exhaust temperature;
• the control unit is operable to sample the exhaust temperature signals at predetermined time intervals, to calculate an average exhaust temperature of the cylinders in accordance with the sampled exhaust temperature signals, to control the respective fuel spray valve of each cylinder to increase the respective amount of fuel supplied to the cylinder if the sampled exhaust temperature of the cylinder is less than a first temperature which is a first deviation below the calculated average exhaust temperature of the cylinders, to control the respective fuel spray valve of each cylinder to decrease the respective amount of fuel supplied to the cylinder if the sampled exhaust temperature of the cylinder is greater than a second temperature which is a second deviation above the calculated average exhaust temperature of the cylinders, and to control a rate of change of an opening amount of the fuel spray valve per a predetermined period in accordance with a load factor of the engine.

An exhaust system control apparatus for an engine having a plurality of cylinders and a fuel spray valve respectively assigned to each cylinder and controllable to supply a respective amount of fuel to the cylinder, the apparatus comprising:

• a control unit for controlling each valve to supply the respective amount of fuel to the cylinder;
• and
• a respective temperature measuring unit assigned to each cylinder and operable to measure a respective exhaust temperature of the cylinder, each temperature measuring unit outputting a respective exhaust temperature signal to the control unit in accordance with the measured respective exhaust temperature;
• the control unit is operable to sample the exhaust temperature signals at predetermined time intervals, to calculate an average exhaust temperature of the cylinders in accordance with the sampled exhaust temperature signals, to control the respective fuel spray valve of each cylinder to increase the respective amount of fuel supplied to the cylinder if the sampled exhaust temperature of the cylinder is less than a first temperature which is a first deviation below the calculated average exhaust temperature of the cylinders, to control the respective fuel spray valve of each cylinder to decrease the respective amount of fuel supplied to the cylinder if the sampled exhaust temperature of the cylinder is greater than a second temperature which is a second deviation above the calculated average exhaust temperature of the cylinders, and to control a rate of chance of an opening amount of the fuel spray valve per a predetermined period in accordance with a load factor of the engine.

A method for controlling an exhaust temperature of exhaust gasses in an engine, comprising:

• measuring the exhaust gas temperatures of the cylinders at predetermined time intervals;
• calculating an average exhaust gas temperature in accordance with the measured exhaust gas temperatures of the cylinders;
• comparing the measured exhaust gas temperature of each cylinder to the calculated average exhaust gas temperature;
• increasing an amount of fuel supplied to the cylinder if the measured exhaust gas temperature of the cylinder is less than a first temperature which is a first deviation below the calculated average exhaust gas temperature of the cylinders;
• decreasing the amount of fuel supplied to the cylinder if the measured exhaust gas temperature of the cylinder is greater than a second temperature which is a second deviation above the calculated average exhaust gas temperature of the cylinders;
• and
• controlling a rate of change of an opening amount of a fuel spray valve per a predetermined period in accordance with a load factor of the engine while the amount of fuel supplied to the cylinder is changed.