High pressure fuel pump has reduced diameter of piston head corresponding with spacing of heat input from compression cavity

摘要

The high pressure pump has a piston without rings in a cylindrical boring, which has a conical region with diameter decreasing from the endface facing the compression cavity. This reduction increases the spacing from the compression cavity. The reduction in diameter of the piston head (7) corresponds to the spacing from the compression cavity (11) of the heat input to the piston (6).