| 摘要 |
PROBLEM TO BE SOLVED: To remove impurities adhered to the periphery of the valve seat of a pressure control valve provided on a common rail automatically in an accumulative fuel supply device in an engine. SOLUTION: In order to control the pressure in an accumulation chamber higher than the open valve pressure of a pressure control valve 25 for a certain period of time at fixed timing when an engine is in operation, the valve element and the valve seat of the pressure control valve 25 are separated forcibly, and then adhered matter around the valve seat are removed by high pressure fuel low on the low pressure side around the valve seat. The adherence prevention control of this nature can be carried out at each fixed timing, for example, at acceleration or deceleration of the engine. Hence, when an internal pressure in the accumulation chamber rises excessively for some reason when the engine is in operation, the pressure control valve 25 opens properly to prevent a common rail 4, injectors 2, and a supply pipe 5 and the like from being damaged. |
