| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rail pressure control device for a common rail type diesel engine surely preventing system breakage by improving valve open response of a pressure reducing valve and immediately opening the pressure reducing valve when rail pressure abnormally rises. <P>SOLUTION: In normal time when rail pressure Prail does not abnormally rises and is not lower than a normal time mode change over determination value Pmode, rail pressure interlocking mode is executed as control of the pressure reducing valve for system protection, and opening pressure of the pressure reducing valve is always changed and valve open response is improved by setting the valve opening pressure Pset of the pressure reducing valve at a higher pressure side than target rail pressure tgtPrail by offset quantity Pofst. In abnormal rise of the rail pressure Prail, the valve opening pressure Pset is increased to upper limit set pressure Plmtl, and the pressure reducing valve is immediately opened when the rail pressure Prail reaches the upper limit set pressure Plmtl. <P>COPYRIGHT: (C)2010,JPO&INPIT |
