An electromagnetically operable fuel injector for a gaseous fuel injection system of an internal combustion engine, the injector having a generally longitudinal axis. which comprises, a ferromagnetic core, a magnetic coil at least partially surrounding the ferromagnetic core and an armature magnetically coupled to the magnetic coil and being movably responsive to the magnetic coil. The armature actuates a valve closing element which interacts with a fixed valve seat of a fuel valve and is movable away from the fixed valve seat when the magnetic coil is excited. The fixed valve seat defines a central fuel opening and a generally annular groove adjacent the central fuel opening, the armature having a generally elongated shape and a generally central opening for axial reception and passage of gaseous fuel from a fuel inlet connector positioned adjacent thereto. The fuel inlet connector and the armature are adapted to permit a first flow path of gaseous fuel between the armature and the magnetic coil as part of a path leading to said fuel valve. A method of directing gaseous fuel through an electromagnetically operable fuel injector for a fuel system of an ? combustion engine is also disclosed.
A fuel injection valve has: a tubular body, a valve seat member, a valve body, a core tube, a bias spring, and an electromagnetic actuator. The core tube is press fitted into the tubular body. The core tube has a first end side opposing an absorption section of the valve body in such a manner as to form an axial gap interposed between the first end side of the core tube and the absorption section. The core tube has a second end side axially extending in the tubular body to a certain position on a way to the second end side of the tubular body. The axially extending second end side of the core tube has an outer periphery which is formed with a reduced diameter section for increasing an accuracy in positioning the core tube when the core tube is press fitted into the tubular body.
A fuel passage is formed through a movable core and a fixed core of a fuel injection valve. Communication passage(s) are formed in the movable core or the fixed core around the fuel passage. The communication passage(s) connect a facing space provided between the movable core and the fixed core with a space remote from the facing space. Fuel flows out of the facing space through the communication passage(s) when the fuel injection valve is opened and fuel flows into the facing space through the communication passage(s) when the fuel injection valve is closed.
In a fuel injection valve in which an outer frame member is press fitted to a limited region of an outer circumference of an inner pipe member in a state that a drive coil is radially sandwiched therebetween, a valve lift amount is accurately adjusted by press fitting the attracting member to the inner pipe member without being adversely affected by a possible deformation of the inner circumference of the inner pipe member on press fitting the outer frame member to the inner pipe member due to a relief space provided in the inner circumference of the inner pipe member for preventing the outer circumference of the attracting member from contacting the inner circumference of the inner pipe member at least at a position just radially inside and axially corresponding to the limited region.
The present invention is directed to an electrical connector that attaches a fuel injector assembly to a vehicle control assembly. The electrical connector comprises a plastic molded body having two integrally formed portions, a base portion and a stem portion, and an electrical contact extending through the body from the stem portion to the base portion. The base is inserted into the fuel injector assembly with the electrical contact engaging a corresponding contact within the fuel injector assembly. Similarly, the electrical contact in the stem portion of the connector is attached to a corresponding contact of a control assembly, which provides the electrical signals to operate the fuel injector. The base portion includes a metallic sleeve that extends between its sidewalls and cooperates with a locking pin that is inserted through openings in the fuel injector assembly to lock the two components together. The sleeve openings are slightly offset from the fuel injector assembly openings so that when the locking pin is inserted, it aligns the two components and urges the electrical connector further into the fuel injector assembly. Additionally, the sides of the connector include deformable "crush pads" that when inserted into the fuel injector assembly are reshaped to provide a "snug" fit between the electrical connector and the fuel injector assembly.
A fuel injector having a fuel flow rate set by injector stroke is disclosed. The fuel injector includes a housing having a hollow passage and a seat disposed at one end of the hollow passage. A needle is slidably mounted in the hollow passage. The needle is operable between a first position wherein the needle engages the seat and a second position wherein the needle is disposed away from the seat. A first flow area is formed by a minimum frusto-conical area between the seat and the needle when the needle is disposed away from the seat. The fuel injector also includes an opening at the one end of the hollow passage proximate to the seat. The opening has a second flow area larger than the first flow area. A method for setting a gaseous fuel injector flow rate with injector stroke is also disclosed.
