Abstract: An exhaust gas purification system includes the DPF to purify particulate matters in the exhaust gas of a diesel engine, comprising a regeneration control device to judge a condition of an engine operation to be an idle operation or not at the time of starting the control operation for regenerating the diesel particulate filter and during the regeneration control operation, when the engine operation is judged to be an idle operation, an idle engine speed is controlled and raised to the predetermined engine speed.

Abstract: An exhaust gas purification system having a diesel particulate filter to purify particulate matter in the exhaust gas G from a diesel engine, wherein a an exhaust gas passage prevention structure or the like is installed in portions where particulate matter in the exhaust gas is collected and accumulated easily, and, the temperature raises easily by the oxidation of accumulated particulate matter, in said diesel particulate filter.

Abstract: A diesel particulate filer unit 1 comprising a filter 4 for capturing particulates in the exhaust gas G of an engine E, and a regeneration control means 50 judging the start of the regeneration operation of said filter 4, according to the comparison between the value measured by exhaust pressure sensors 51, 52 and a predetermined exhaust pressure judgment value &Dgr; Pes, Pes, Res wherein said regeneration control means 50 is configured to estimate the ash accumulated quantity SAsh of ash leaked into the exhaust gas G and accumulated in said filer 4, and correct said exhaust pressure judgment value &Dgr;Pes, Pes, Res for judging the regeneration operation start based on this. Thereby, a diesel particulate filter that can judge the regeneration start timing appropriately, taking accumulation and deposit of ash generated from lubricant oil on the filter into consideration, and remove particulates efficiently all the way preventing the filter from clogging is provided.