Distribution type fuel injection pump

A fuel injection pump for use in a fuel injection combustion engine, comprising:

• a housing having a fuel chamber therein;
• a plunger movably mounted in said housing and forming a plunger chamber over a head of said plunger;
• first cam means fixedly mounted on said plunger;
• second cam means turnably mounted on said housing and cooperating with said first cam means so as to cause reciprocal motion of said plunger along the axis thereof during plunger rotation with respect to said cam means, said second cam means being capable of being positioned in one of a plurality of angular positions thereof;
• fuel supply means for introducing fuel into said plunger at the suction stroke of said plunger;
• a delivery port for feeding fuel to the engine from said plunger chamber at the delivery stroke of said plunger;
• a leak port formed in said plunger and connected to said plunger chamber;
• a control sleeve slidably mounted on said plunger for normally closing said leak port and for connecting said leak port to said fuel chamber at the end of the delivery stroke to terminate the fuel injection;
• a governor device actuating said control sleeve for controlling the quantity of fuel to be injected;
• injection timing control means for controlling the angular position of said second cam means in response to the engine speed so as to displace said second cam means to advance the injection timing in response to an increase in engine speed;
• said injection timing control means comprising a first piston slidably fitted into a first cylinder and connected to said second cam means via a first rod, said first piston being urged by elasticity of a first spring to urge said second cam means towards injection timing retarding and said first piston being effected by hydraulic pressure of fuel, in response to the engine speed, introduced into a first pressure chamber to move said second cam means towards injection timing advancing against said elasticity of said spring, said first piston moving in accordance with the difference between said elasticity and said pressure in said pressure chamber, said first piston being provided with a fuel passage therethrough for communicating said first pressure chamber with said fuel chamber in said housing, said fuel passage being in comunication with said fuel chamber through said housing;
• and
• injection timing adjusting means for providing an adjusted movement of said second cam means toward a predetermined angular position to advance the injection timing at the engine start, said injection timing adjusting means comprising a wax pellet actuator contained in said first pressure chamber of said injection timing control means, said actuator being provided with a wax pellet capable of expanding or contracting in response to engine temperature, a third rod connected to said wax pellet actuator at its one end and a return spring provided at its other end to urge same towards said wax pellet, said third rod having a cam face disposed on the side face thereof to bear against said first piston, said cam face provided with a first cam face for moving said first piston of said injection timing control means in the direction of said fuel injection timing advancing at the time of engine start in cold conditions, a second cam face for freeing said injection timing advancing of said injection timing control means when said engine has reached a warmed-up condition.