| 摘要 |
<p>PURPOSE:To avoid a half flameout condition of burning, while operating regeneration process without casing closing trouble of an exhaust valve, by adjusting a throttle rate of a throttle valve provided on an exhaust passage side so as to hold exhaust pressure at a constant rate on the upside stream side from the throttle valve provided on the exhaust passage side, at the time of regeneration of a filter. CONSTITUTION:On the basis of a regeneration command of a filter 7, electrification is carried out in a heater 8 by a controller 31 to heat air supplied from an intake passage 3 to an engine 1 through branch intake passage, so as to promote temperature increase of exhaust gas. A fuel injection pump 2 is controlled by the controller 31, so that the number of revolution of the engine 1 is set to a high idling number of revolution to increase an amount of exhaust gas supplied to an exhaust passage 6. A vacuum control valve 19 is driven by the controller 31 to make air suction force of a vacuum pump 22 act on respective air flow passages 20, 21. Namely, regenerating process is carried out by increasing exhaust pressure in the exhaust passage 6 by respective throttle valves 9, 10. When exhaust pressure is increased, for example, up to a level which exceeds the force of spring 28, the air flow passage 21 is shut out by an exhaust pressure control valve 26 so as to decrease the throttle amount of the throttle valve 10.</p> |
