Delivery valve.

摘要

An unloading delivery valve (10) for incorporation in a fuel delivery passage to a compression ignition engine has a valve member (17) slidable in a bore (14) which forms part of the flow path of the delivery passage. The valve member has a head (18) having on its under surface a portion (19) shaped to cooperate with a seating (16) at an end of the bore. The valve head is spring loaded into engagement with the seating (16) and is lifted from the seating when fuel flows to the engine. An unloading collar (21) is mounted on the valve member and cooperates with the wall of the bore to determine the return flow of fuel which flows when the valve head moves into engagement with the seating. A drilling (24) is formed in the collar to modify the return flow and the drilling is positioned so that during flow of fuel to the engine, the fuel which flows through the drilling impinges on the valve head at a position inwardly of the shaped portion (19). <IMAGE>