Injection pump for internal combustion engines

An injection pump for internal combustion engines, having a housing, a pump piston bushing in said housing, a pump piston guided in said bushing, said pump piston having control edges for controlling the beginning and end of an injection event, the control edges cooperating with control bores provided in the wall of said pump piston bushing that permit fuel flow from and into a collecting chamber surrounding the pump piston bushing, into which collecting chamber fuel is delivered under pressure, and from which collecting chamber excess fuel, or fuel overflowing at the end of an injection event, is diverted, a suction valve (10) that opens toward the collecting chamber is connected to the collecting chamber for the delivery of fuel, while for the fuel diversion, said collecting chamber is embodied as a reservoir chamber (9) having pressure maintenance valve (11) which opens in a direction away from the reservoir chamber (9), said control bores (7) of the pump piston bushing (1) are connected to said reservoir chamber (9) and said reservoir chamber (9) is concentric with a suction chamber (4) which is connected to said reservoir chamber via said suction valve (10).