DUTY CONTROLLER OF ELECTRIC MOTOR AND EXHAUST EMISSION CONTROL DEVICE OF DIESEL ENGINE

摘要

PURPOSE:To provide a duty controller of an electric motor and an exhaust emission control device of a diesel engine at low cost, capable of driving the electric motor having little rush current. CONSTITUTION:A filter 7 and an electric heater 8 are provided on an exhaust system of a diesel engine 1, and an electrically powered air pump 11 supplies secondary air to the filter 7. An ECU 12 is provided with a microcomputer 13 for outputting a low-frequency duty signal as a driving signal of an electric motor 11a of the electrically powered air pump 11, a high frequency generating circuit 14 for outputting a high-frequency pulse signal, and an AND gate for outputting a signal by taking the logical product of the signal of the high frequency generating circuit 14 and the signal of the microcomputer 13. The microcomputer 13 ignites particulates collected by the filter 7 in an electric heater 8 and also incinerates particulates collected by the filter 7 by driving the electric motor 11a, so as to regenerate the filter.