Fuel injection pump for internal combustion engines

Claim 1

A fuel injection pump for internal combustion engines having a pump housing a cam drive to effect rotational and reciprocal movement for the supply movement of at least a pump piston, said pump including a portion supported in said pump housing which is adjustable relative to its rotating portion counter to a restoring force for the purpose of adjusting the onset of injection by means of a displaceable adjusting piston in a working cylinder, said working cylinder being at least indirectly connected to receive fuel from a fuel supply pump, the supply pressure of said fuel supply pump being controllable in proportion to the rpm by means of a pressure control valve and said supply pressure being further controllable by means of the supplementary discharge of a partial quantity of fuel through a discharge channel including an overflow valve, characterized in that said injection pump is controlled by means of a hydraulic rpm governor, said rpm governor including a governor piston extending into said pump housing having opposite end portions one of which is exposed to the supply pressure of said fuel supply pump and adjustable counter to the force of governor springs within said pump housing, a bushing surrounding a portion of said governor piston and fixed in a bore in said pump housing, one end of said governor piston extending into a pressure-relieved chamber which encompasses said governor springs, and further that said governor piston at least controls a relief channel in said housing, said bushing and said governor piston which indirectly effects pressure in said working cylinder of said adjusting piston, said relief channel including mouth portions in said bushing and said governor piston arranged to overlap one another to a greater or lesser extent during movement of said governor piston for controlling the cross section of said mouth portions in said bushing in said pump housing for controlling discharge of fuel from said injection pump.