EXHAUST GAS TEMPERATURE RAISING DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To prevent generation of large pressure releasing sound at termination of a temperature raising control which uses increase in engine idle speed in combination with restricting of an exhaust flow rate.

SOLUTION: In this exhaust gas temperature raising device of internal combustion engine, an exhaust temperature is increased as required to ensure a temperature needed in a particulate filter 6 (post-processing device) in the middle of an exhaust pipe 4 at idling. This device comprises: an exhaust brake 13 (exhaust restriction means) for suitably restricting the exhaust flow rate; and a control device 9 which performs temperature raising control of increasing the engine idle speed of an diesel engine 1 to a target engine speed higher than usual when increase in the exhaust temperature is required and restricting the exhaust flow rate by the exhaust brake 13. An appropriate time delay is set to the control device 9 such that the restriction of the exhaust flow rate by the exhaust brake 13 is released after decrease in the engine idle speed to a predetermined engine speed at the termination of the temperature raising control.

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