Patent Application
20230014983
The present disclosure relates generally to internal combustion engines, and more particularly to common rail fuel systems for such engines.
Common rail fuel injection systems, commonly used in diesel engines, deliver high pressure fuel to combustion chambers where the fuel may be combusted to create mechanical power. Such systems may include a high pressure fuel pump delivering fuel to a fuel rail or fuel plenum. The fuel rail supplies high pressure fuel to each fuel injector through a plurality of conduits extending between the fuel rail and the fuel injectors. When the fuel injectors are actuated, high pressure fuel is delivered from the fuel rail, through the fuel injector, and injected into a corresponding combustion chamber. Such common rail fuel systems may be coupled to the engine and include various pipes, tubes, quills, or conduits forming the fuel connection between the fuel rail and the fuel injector. In some instances such fuel connections may allow for detrimental engine fluids, such as fuel or oil vapors to be release via the various connection points or joints in common rail fuel systems and associated engine housings.
U.S. Pat. No. 6,237,569 B1 (“the '569 patent) discloses a common rail fuel system where the common rail is coupled outside of the crankcase of the engine and includes fuel connections extending through portions of the cylinder head to the fuel injectors. The fuel rail of the '569 patent is encapsulated in liquid-tight chamber to thereby form a leak chamber.
The common rail fuel system of this disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem.
In one aspect, a system for coupling a fuel rail of a common rail fuel system to an internal combustion engine may include an engine wall having a plurality of openings. The fuel rail may have a main pipe portion located outside the engine wall, and a plurality of outlet pipes monolithically formed with the main pipe portion, each of the plurality of outlet pipes extending into a corresponding one of the plurality of openings of the engine wall. The system may further include a seal located in sealing engagement with each of the plurality of openings and a corresponding outlet pipe.
In another aspect, a system for coupling a fuel rail of a common rail fuel system to an internal combustion engine may include an engine wall having a plurality of openings. The fuel rail may include a main pipe portion located outside the engine wall and extending parallel to the engine wall and a plurality of outlet pipes monolithically formed with the main pipe portion. Each of the plurality of outlet pipes may extend into a corresponding one of the plurality of openings of the engine wall. The system may further include a seal located in sealing engagement with each of the plurality of openings and a corresponding outlet pipe. The system may also include a plurality of fasteners fixedly coupling the fuel rail to the engine wall, each fastener of the plurality of fasteners extending into a corresponding securement opening in the engine wall.
In another aspect, a system for coupling a fuel rail of a common rail fuel system to an internal combustion engine may include an engine wall having a plurality of openings. The fuel rail may include a main pipe portion located outside the engine wall and extending parallel to the engine wall and a plurality of outlet pipes monolithically formed with the main pipe portion. Each of the plurality of outlet pipes may extend into, through, and beyond a corresponding one of the plurality of openings of the engine wall. The system may also include a seal located in sealing engagement with each of the plurality of openings and a corresponding outlet pipe. The system may further include a plurality of fasteners fixedly coupling the fuel rail to the engine wall, each fastener of the plurality of fasteners extending into a corresponding securement opening in the engine wall.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “having,” including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Moreover, in this disclosure, relative terms, such as, for example, “about,” substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in the stated value.
The fuel rail 124 may be a single, monolithic tube or pipe structure that includes a longitudinal main pipe portion 132 and a plurality of outlet pipes 134. The main pipe portion 132 of fuel rail 124 extends generally parallel with the length of the engine 100, and parallel to a generally planar portion of a wall 154 of valve cover 106. As best shown in
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The disclosed aspects of the present invention may be used in any engine using a common rail fuel system. For example, the system of the present disclosure may be used in a diesel internal combustion engine with a common fuel rail used to deliver high pressure fuel to fuel injectors of the engine. The fuel injectors may inject the high pressure fuel to combustion chambers for driving the pistons and crankshaft of the engine.
The present disclosure helps to avoid dangerous engine fluids from escaping the engine 100. For example the monolithic fuel rail 124 sealingly extending into a wall of the engine (through the valve box wall 154) provides a fuel rail coupling arrangement that helps to avoid the leaking of dangerous engine fluids, such as fuel and/or oil vapors, from the engine 100. The coupling arrangement helps to limit the number of potential leak paths at the interface of the interior and exterior of the engine 100. The coupling arrangement also helps to limit the number of parts or connections at the interface of the interior and exterior of the engine 100, and thus helps to reduce the complexity of assembly and maintenance in the area. Fewer parts may result in a reduction in cost because fewer parts are needed to be manufactured and there may be a reduction in manufacturing costs. The reduction in parts also means that there is additional space within the assembly that may be used otherwise in the design.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system without departing from the scope of the disclosure. Other embodiments of the system will be apparent to those skilled in the art from consideration of the specification and practice of the counterweight system disclosed herein. For example, while the present disclosure describes the monolithic fuel rail 124 extending through a valve cover 106 of the engine, it is contemplated that the fuel rail 124 could alternatively extend into other walls of the engine, such into or through a wall of a cylinder head 104. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
