The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention.
A fuel filter 24 is connected to an inlet tube 13a, which in the preferred embodiments is integral with a pole piece 13b but can be separate components coupled to each other. A portion of the inlet tube 13a is disposed in the overmolded plastic member 20, which includes inlet passage 26. The inlet passage 26 serves as part of the gaseous fuel passageway of the gaseous fuel injector 10. A fuel filter retainer member 28 and a preload adjusting tube 30 are provided in the inlet passage 26. The adjusting tube 30 is positionable along the longitudinal axis 18 before being secured in place, thereby varying the length of an armature bias spring 32. In combination with other factors, the length of the spring 32 controls the quantity of gaseous fuel flow through the gaseous fuel injector 10. The overmolded plastic member 20 also supports an electrical connector 20a that receives a plug (not shown) to operatively connect the gaseous fuel injector 10 to an external source of electrical potential, such as an electronic control unit ECU (not shown). An elastomeric O-ring 34 is provided in a groove on an exterior extension of the inlet member 24. The O-ring 34 sealingly secures the inlet member 24 to a gaseous fuel supply member (not shown), such as a fuel rail and an outlet 14 to an intake manifold such as, for example, the intake manifolds shown in copending Application entitled “Fuel Injection System with Cross-Flow Nozzle for Enhanced Compressed Natural Gas Jet Spray” (Attorney Docket No. Siemens 2006P13279US (051252-5299), which is incorporated by reference in its entirety herein this application.
The coil housing 22 encloses a coil assembly 40 as shown in
The body shell 50 engages the body 52. The armature guide eyelet 56 is located on an inlet portion 60 of the body 52 so as to contact the armature 46. An axially extending body passage 58 connects the inlet portion 60 of the body 52 with an outlet portion 62 of the body 52. The armature passage 54 of the armature 46 is in fluid communication with the body passage 58 of the body 52. A seat 64, which is preferably a metallic material, is mounted at the outlet portion 62 of the body 52.
As shown in
Operative performance of the gaseous fuel injector 10 is achieved by magnetically coupling the armature 46 to the end of the inlet member 26 that is closest to the inlet portion 60 of the body 52. Thus, the lower portion of the inlet member 26 that is proximate to the armature 46 serves as part of the magnetic circuit formed with the armature 46 and coil assembly 40. The armature 46 is guided by the armature guide eyelet 56 and is responsive to an electromagnetic force generated by the coil assembly 40 for axially reciprocating the armature 46 along the longitudinal axis 18 of the gaseous fuel injector 10. The electromagnetic force is generated by current flow from the ECU (not shown) through the coil assembly 40. Movement of the armature 46 also moves the closure member 68. The closure member 68 opens and closes the seat orifice 76 of the seat 64 to permit or inhibit, respectively, gaseous fuel from exiting the outlet of the gaseous fuel injector 10. In order to permit flow through the seat orifice 76, the seal between the tip of closure member 68 and the seat 64 is broken by upward movement of the closure member 68. The closure member 68 moves upwards when the magnetic force is substantially higher than needed to lift the armature needle assembly against the force of spring 32. In order to close the seat orifice 76 of the seat 64, the magnetic coil assembly 40 is de-energized. This allows the tip of closure member 68 to re-engage .surface 80 of seat 64 and close passage 76. During operation, gaseous fuel flows from the fuel inlet source (not shown) through the fuel inlet passage 26 of the inlet member 24, the armature passage 54 of the armature 46, the body passage 58 of the body 52, and the seat orifice 76 of the seat 64 and is injected as gaseous fuel column GF from the outlet 14 of the gaseous fuel injector 10 (
As shown in
The retainer portion 110 of the internally mounted nozzle engages numerous surfaces of a locking portion 90 as shown in
The retainer portion 110 includes a portion, i.e., flange 115, internally mounted to the gaseous fuel injector 10 proximate the outlet 14. The flange 115 of the retainer portion 110 is secured by a securement portion 90 of the body 50.
The flow modifier portion 120 affects the flow distribution pattern of gaseous fuel through the internally mounted nozzle 100 as shown in
The first flow channel 123 extends along a first axis 126a or second axis 126b at a flow angle θ1 relative to axis 18. Preferably, the flow angle θ1 is generally orthogonal to the longitudinal axis 18 as shown in
In one preferred embodiment, illustrated in
Gaseous fuel flows through the seat orifice 76, along the flow passage 121, and may be dispersed through one, two, three, four, or other multiple flow channel configurations of the internally mounted nozzle 100. Thus, the resulting multiple columns of gaseous fuel are dispersed perpendicular to the longitudinal axis 18 of the gaseous fuel injector 10 to improve the mixing characteristics within the intake manifold.
It is believed that at least the preferred embodiments described above in relation to the nozzle 100 alleviate back-flow of the air-fuel mixture into the internal combustion engine's intake plenum or into other engine cylinders in that the preferred embodiments provide a cloud of gaseous fuel, which can be entrained by the airflow towards the intake for dispersal into the combustion chamber. The discharge pattern of gaseous fuel delivered to the intake manifold of the present invention is believed to improve the air-fuel mixture and drivability problems in certain applications.
In another preferred embodiment, illustrated in
It should be noted that even though the external nozzle 100 has been illustrated as a monolithic structure, the nozzle 100 can be formed by securing two or more portions of the nozzle 100 together. For example, the retainer portion 110 and flow modifier portion 120 can be separate structures secured to each other by a suitable technique, such as, for example, welding, laser welding, friction welding or bonding.
While the present invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims, and equivalents thereof.