A fuel rail assembly that possesses a number of novel features relating to joints for connecting metal tubes such as crossover, inlet, and return tubes, to main plastic fuel tubes; retainer clips for retaining various fuel handling components in sockets formed in the plastic fuel tubes, such as retaining a fuel pressure regulator in a plastic cup of a main plastic fuel tube; and the construction of various plastic sockets in a main plastic fuel tube, such as the cups for receiving the fuel injectors.
Projection welding is used to join a needle guide member and a valve seat member together preparatory to their assembly into the nozzle of a fuel injector. Various embodiments are disclosed, including various ways for creating the projections. In the preferred embodiment the projections on the end face of the guide member are made my forming a small holes in the frustoconical surface of the guide plate. As the tool is used to form the small holes in the guide plate, the material of the guide plate is displaced creating small projections from the frustoconial guide surface.
Fuel injector has combination valve-armature fabricated by laser welding relatively more magnetically permeable armature element to relatively less magnetically permeable valve element. Valve element contains sealing ring and landing ring, the latter being circumferentially discontinuous because of fuel passage holes through the valve element, the former being non-symmetrical so that magnetic opening force causes valve-armature to open by tilting about consistent circumferential location on valve element. Initial opening tilting motion is stopped by corrugated stop surface of annular stop member with final tilting motion occurring about the corrugated stop surface until the full perimeter of the valve element abuts the full perimeter of the corrugated stop surface. Actuator has bobbin-mounted coil inserted into frame and encapsulated by outer plastic body. Conical disk spring acting between fuel inlet tube and coil forces one end of the latter against valve body member while forming a barrier between fuel inlet tube and other end of coil so that plastic does not intrude into interior of mechanism during injection molding of outer plastic body. Object of invention is lower fabricating cost for specified performance of injector.
A system and method for operating high speed solenoid actuated devices such as electromagnetically operated high pressure fuel injectors require an initial high power boost to start the movement of an armature followed by a medium power boost to continue the movement of the armature to its end position and a low power control to hold the armature at its end position so that when the power is removed, the armature returns to its rest or beginning position. The system here details the logic and control necessary to provide six stages of power control, including both voltage and current control, to accomplish high speed operation both in moving the armature from its beginning to end position but also to return the armature from its end to its beginning position.
A high pressure fuel injector has a railplug ignitor assembly disposed on its nozzle. The injected fuel travels down the bore of the railplug. The railplug delivers a plasma that travels down the bore of the railplug in timed relation to the injected fuel to ignite the fuel.