High-pressure fuel pump for i.c. engine with common rail feed has piston rod rings with sufficient power to balance forces on polygonal ring

摘要

The high-pressure pump, having a number of pistons located round a polygonal ring (4) driven by a cam (3) turned by the engine and actuating piston rods (2) pressed against it by springs (7), has the springs made with sufficient power to balance the forces applied to the polygonal ring in the even of failure caused by the high pressure of fuel against the pistons. The power of the springs is about four times that required for their dynamic performance.