High pressure piston pump driving device for internal combustion engine, has cam with cam lobe curve having form in its section that is obtained from overlapping of alternation of sinusoidal waves

摘要

The device has a cam cooperating with a pump piston to generate forward and backward motions of the piston. The cam has a cam lobe curve (18) whose form is modified from a form corresponding to a sinusoidal wave (19) such that piston acceleration increases and decreases, respectively, at start and end of an upward travel of a section of the curve in comparison to the wave. The curve has a form in its section that is obtained from an overlapping of alternation of the wave (19) and another sinusoidal wave (20) which has a double the frequency of and a lesser amplitude than the wave (19).