three supply phases 48 a 48 b and 48 c are provided per rotation of drive shaft 36 supply phases 48 a 48 b and 48 c are evenly spaced within a working cycle of internal combustion engine 10 it can be seen that pressure pr in fuel collection line 28 is comparatively stable despite the large injected fuel quantity mi fig5 shows a situation in which change from a supply rate having one supply phase 48 per rotation of drive shaft 36 to a supply rate having three supply phases 48 a 48 b and 48 c per rotation of drive shaft 36 takes place a total of four working cycles i e eight rotations of crankshaft 34 of internal combustion engine 10 are plotted for reasons of clarity only one injection pulse is provided with reference numeral 50 injection pulses 50 themselves are only indicated by a line for representational reasons although in reality they correspond to an approximately acute delta pulse high pressure fuel pump 18 initially operates at a supply rate of one supply phase 48 per rotation of drive shaft 36 therefore pressure pr in fuel collection line 28 initially rises steeply and then drops again with each injection pulse 50 in a stepped manner given a crank angle of approximately 450 u00b0 dot dash line 54 control and regulating device 44 specifies on the basis of signals from sensors 40 42 and 44 that the supply rate is to be increased to three supply phases 48 a 48 b and 48 c per rotation of drive shaft 36 however this switch over command 54 is not realized immediately but only executed when the middle of next supply phase 48 has been reached this is indicated by a.