| 摘要 |
The degree of oil deterioration is obtained from the concentration of soot in the engine oil, and the allowable upper limit value for the compressor outlet temperature is obtained from this degree of oil deterioration (step ST1). The allowable upper limit supercharging pressure corresponding to this upper limit value for the compressor outlet temperature is calculated. A target supercharging pressure, which can be determined from the operating state of the engine, is compared to the allowable upper limit supercharging pressure, and when the target supercharging pressure is equal to or less than the allowable upper limit supercharging pressure, the turbocharger is controlled with this target supercharging pressure as the control supercharging pressure. When the target supercharging pressure exceeds the allowable upper limit supercharging pressure the turbocharger is controlled with the allowable upper limit supercharging pressure as the control supercharging pressure, and the EGR valve is controlled so as to prevent the EGR rate from diverging from a target EGR rate (step ST5). |
