Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
1999-09-29
2001-05-08
Yuen, Henry C. (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel injection system
C123S468000
Reexamination Certificate
active
06227170
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel rail (also called a fuel gallery or fuel distributor) fitted to an engine of an automobile and the like for delivering gasoline or the like to the engine through distribution among respective cylinders thereof.
2. Description of the Related Art
The fuel rail is one of primary components among products for a fuel injection system for use in the middle between a fuel tank and the engine, and as such, pressure tightness, airtightness (leak-proof), and oil tightness are strictly required of it owing to needs of ensuring that it has a function of stably delivering a combustible such as gasoline or the like.
A conventional fuel rail has a construction, wherein a fuel pipe is provided with a plurality of openings to serve as a fixture mount for respective injectors in dedicated use for respective cylinders of an engine and integrally formed mainly of aluminum by die casting, and an electrical wiring insert-molded in a covering made of synthetic resin which is used for activating respective injectors is attached to a side of the fuel pipe separately for connection therewith. The electrical wiring insert-molded in the covering made of synthetic resin is used for driving a solenoid valve of the respective injectors, and a cord fitted with a female connector is drawn out up to the tip thereof while a male connector is fitted to the respective injectors protuberantly.
With the conventional fuel rail described above, the electrical wiring insert-molded in the covering made of synthetic resin is disposed so as to be used in parallel therewith, and this configuration not only has taken much space of an engine room but also has required additional steps in an assembling process, resulting in a higher cost of fabrication.
The electrical wiring insert-molded in the covering made of synthetic resin is formed by embedding an electrical wiring into the covering made of synthetic resin by means of insert-molding, but it is susceptible to the effect of severe ambient conditions existing inside an engine room due to the fact that the covering can not be expected to have a sufficient thickness in view of economics and needs for weight reduction, and a cord is used for connection thereof with the respective injectors, thus posing uncertain factors for occurrence of troubles such as a faulty motion caused to occur in activation of the injectors.
Similarly, the thickness of the fuel rail itself is under constraints, and this also has posed a problem with reliability thereof in respect of pressure tightness, airtightness (leak-proof), and oil tightness as described in the foregoing.
SUMMARY OF THE INVENTION
In light of the circumstances described above, the present invention has been developed, and an object of the invention is to provide a method of fabricating an engine fuel rail, compact and having highly reliable functions, wherein the number of fabrication steps as well as a cost of fabrication can be reduced because it is a component molded integrally with electrical wiring by means of the insert molding, and.
To achieve the above object, the method of fabricating an engine fuel rail comprises the steps of integrally molding a fuel delivery pipe from a synthetic resin, provided with a plurality of openings to serve as a fixture mount for respective injectors, said openings being branched from a fuel delivery path, assembling an electrical wiring formed of a plurality of wiring members which are securely held with a plurality of blocks by insert molding of the synthetic resin, insert setting the fuel delivery pipe and the electrical wiring in a mold, molding the fuel delivery pipe and the blocks by means of a primary molding, and molding the fuel delivery pipe integrally with the electrical wiring in a base member of the engine fuel rail, molded from the synthetic resin, by means of a secondary molding. The base member is provided with an opening at one end thereof to serve as a socket on an input side for the electrical wiring, and is also provided with a plurality of branching blocks formed integrally therewith at the side thereof, each having both an opening to serve as the fixture mount for the respective injectors and an opening to serve as a socket on an output side for the electrical wiring.
With the configuration described above, since the second molding is applied to the base member while the fuel delivery pipe and the electric wiring formed by the primary molding serve as an insert-molded product, the fuel rail has a high strength with high security because of a double structure formed by the fuel delivery pipe of the primary molding and base member of the secondary molding. Accordingly, even if the base member is formed to have a thin thickness or the electric wiring approaches the fuel delivery path for rendering the fuel rail compact, it is possible to secure safety without leakage of fuel owing to the strength of the fuel delivery pipe.
In accordance with a first aspect of the invention, there is included a case of molding the oil delivery path without executing the primary molding described above, that is, a case of molding the oil delivery path in the secondary molding. Particularly, the plurality of wiring members, which are integrally connected with one another by connection ribs, are formed at the same time when applying press working to a metal sheet in the step of assembling the electrical wiring, and the connection ribs are removed after the blocks for fixing the wiring members with one another are molded, so that the assembly of the electrical wiring for properly arranging the wiring members is made with ease.
Thus, the engine fuel rail of the invention has advantageous effects such as not only rendering the product lighter in weight and compact because of the insert setting of the fuel delivery pipe and the electrical wiring which serve as a primary molded product and are disposed rationally so as to be close to each other, and a rational thickness of the base member as a secondary molding by the insert-molding in the case that it is an insert-molded product integral with the electrical wiring, but also preventing fuel leakage with assurance and providing the engine fuel rail as a product highly reliable that can withstand severe ambient conditions existing inside an engine room and can be fabricared with ease.
REFERENCES:
patent: 4570601 (1986-02-01), Ito et al.
patent: 5339786 (1994-08-01), Martin
patent: 5390638 (1995-02-01), Hornby et al.
patent: 5616037 (1997-04-01), Lorraine et al.
Der neue Zwölfzylinder-Motor fur die neue Mercedes-Benz S-Klasse Teil 2,Motortechnische Zeitschrift52 (1991), pp. 220-232. (German language article.)
Flynn ,Thiel, Boutell & Tanis, P.C.
Gimie Mahmoud
Kojin, Ltd.
Yuen Henry C.
LandOfFree
Engine fuel rail and method of fabricating same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Engine fuel rail and method of fabricating same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Engine fuel rail and method of fabricating same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2571269