Liquid fuel injection pumping apparatus

摘要

A liquid fuel injection pumping apparatus includes an injection pump to which fuel is supplied by a feed pump by way of a throttle which includes an axially movable member. The pressure of fuel upstream of the throttle is controlled by a valve so that its pressure varies in accordance with the law RN2. The apparatus also includes a further valve which provides a substantially constant pressure and this pressure is applied to a piston by way of a further orifice the size of which depends upon the setting of the throttle. The further piston influences the timing of injection of fuel by the apparatus and in addition a pressure which is proportional to the square of the speed at which the apparatus is driven, is generated and is also used to influence the timing of delivery of fuel.