Liquid fuel injection pump

摘要

A fuel pumping apparatus includes an injection pump to which fuel is supplied by a low pressure supply pump. A shuttle located in a cylinder has one end connected to the injection pump and the other end to the supply pump when it is desired to feed fuel to the engine. The movement of the shuttle represents the amount of fuel supplied to the injection pump and this movement is measured and the signal supplied to a processing circuit which also receives a demand signal. The movement of the shuttle is halted by the gradual closure of communication between the one end of the cylinder and the injection pump. This is achieved in the example by a passage moving out of registration with a port. The rate of flow of fuel from the pump to the cylinder is controlled by a fuel control device the setting of which is determined by the processing circuit which strives to ensure that the actual amount of fuel supplied to the injection pump is equal to the desired amount.