Abstract: Flammable fine particles (particulates) consisting principally of carbon and hydrocarbons are discharged from a diesel engine to its exhaust system. A diesel particulate oxidizer (DPO) is disposed in the exhaust passage for collecting and burning the particulates without allowing the particulates to be discharged directly to the atmosphere. This DPO comprises a ceramic foam with catalyst. When the quantity of particulates collected is above a predetermined value, the DPO will undergo clogging. To prevent this, a high temperature gas containing oxygen is fed to the DPO to burn (regenerate) the collected particulates. In order to accelerate the normal regeneration of the DPO, there are provided a regeneration means for making a retard control of the fuel injection timing in the diesel engine, and a regeneration timing control means for controlling the operation of the regeneration means. Further, there is provided a regeneration timing detection means for detecting the regeneration timing of the DPO.

Abstract: A particulate oxidizer system for a diesel engine comprises a diesel particulate oxidizer (DPO) in the exhaust line to collect and burn particulates in the exhaust. The DPO comprises ceramic foam with a catalyst. When the quantity of particulates in the DPO reaches a predetermined value, high temperature gas containing oxygen is fed to the DPO to burn off (regenerate) the collected particulates. This is achieved by retard control of the injection timing under control of an engine control unit (ECU). A regeneration timing detection means detects the regeneration timing in the DPO. When the quantity of particulates in the DPO falls below a predetermined value, the ECU provides a signal to increase the idling revolution of the engine.