Fuel injection pump for internal combustion engines

Claim 1

A fuel injection pump for internal engines comprising: an adjusting piston which is adjustable for the purpose of adjusting the onset of fuel injection; said adjusting piston including a work chamber on one end and a restoring force chamber on its other end; a suction chamber; a flow passage between said suction chamber and said work chamber; a pressure control valve; said pressure control valve including a pressure chamber and a restoring chamber and a control piston which separates said pressure chamber in said pressure control valve from said restoring chamber in said pressure control valve; said pressure control valve including an outflow cross-section which is controlled by said control piston; a supply pump; means supplying fluid from said supply pump into said suction chamber and said pressure chamber of said pressure control valve in proportion to rpm which fluid pressure acts on said adjusting piston counter to a restoring force and applies pressure on said control piston for determining an outflow cross section of said outflow cross-section of said pressure control valve for applying a restoring force on said adjusting piston; a throttle in said control piston connection between the pressure chamber of said pressure control valve and said restoring chamber of said pressure control valve; an outflow control valve operable in dependence of engine adjusting variable; an outflow channel from the restoring chamber of said pressure control valve connected with said outflow control valve; a relief channel including a pressure maintenance control valve means disposed parallel to the pressure control valve and connected to the means for supplying fluid to said pressure chamber of said pressure control valve and to said outflow control valve for control of fluid from said restoring force chamber of said pressure control valve and from said pressure maintenance control valve means.