Fluid sprinkling – spraying – and diffusing – Including valve means in flow line – Reciprocating
Reexamination Certificate
2000-05-15
2001-07-10
Scherbel, David A. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Including valve means in flow line
Reciprocating
C239S585200, C239S585300, C239S585400, C239S585500, C239S900000, C251S129160, C251S129210
Reexamination Certificate
active
06257509
ABSTRACT:
BACKGROUND INFORMATION
The present invention relates to a fuel injector.
U.S. Pat. No. 5,156,124 already describes a fuel injector, which can be actuated electromagnetically. To that end, the fuel injector has the usual component parts of an electromagnetic circuit, such as a magnetic coil, an internal pole, and an external pole. This known injector is a so-called “side-feed injector”, where the fuel supply takes place substantially underneath the magnetic circuit. Contact pins originating at the magnetic coil protrude from the fuel injector, which are injection-molded around with plastic over a certain length and are embedded in this. The plastic injection molding is applied at one end of the fuel injector and does not constitute an independent component part of the fuel injector.
The same applies to the fuel injector known from German Patent No. 34 39 672. Here also, contact pins originating at the magnetic coil protrude toward an electric attachment plug which is formed of plastic and partially surrounds the contact pins behind the magnetic coil. In this context, the plastic injection molding forming the attachment plug is injection molded on the metallic valve housing.
In German Published Patent Application No. 197 12 591, it was already proposed to assemble a fuel injector of two preassembled subassemblies, a functional part and a connecting part, which are produced and adjusted separately, and are subsequently fixedly interconnected. By connecting the two subassemblies, an electrical and a hydraulic connection is provided as well. The joining of the two subassemblies is carried out with the assistance of ultrasonic welding, bonding, or crimping.
SUMMARY OF THE INVENTION
The fuel injector according to the present invention has the advantage that it can be manufactured in a simple and inexpensive manner, and mounted securely and reliably. Furthermore, according to the present invention, a particularly compact design is achieved for the fuel injector. In addition, it is an advantage that a great mechanical stability of the fuel injector is achieved. Furthermore, it is guaranteed that the electrical connecting elements are safe and protected inside the injector.
Moreover, the designs of the fuel injector can be varied very easily. This is achieved in that two subassemblies of the fuel injector, a functional part and a connecting part, are preassembled or adjusted separately from each other. In this context, the functional part includes an electromagnetic circuit and a seating valve made up of valve-seat body and valve-closure member. On the other hand, the electrical and the hydraulic connections of the fuel injector are provided in the connecting part. All described exemplary embodiments of the fuel injectors have the advantage of an inexpensive producibility, including a great number of design variants, Functional parts, which are manufactured in great quantities, largely of the same design (differences, e.g., in the magnitude of the valve needle lift or in the number of turns per unit of length of the magnetic coil), can be connected to a great number of different connecting parts differing, for example, in the size and form design, in the design of the electric attachment plug, and the fasteners for the installation in a receiving socket or on a fuel distributor, in the construction of the lower end face of the connecting part, or also with regard to their color, their marking, their lettering, or another identification. Thus, the logistics during the manufacture of fuel injectors is fundamentally simplified.
Due to the separation into two subassemblies, the advantage ensues that all negative influences during the manufacture of the connecting part, which is substantially made of plastic (high injection molding pressures, development of heat) are kept away from the components parts of the functional part which perform the important valve functions. The relatively dirty injection molding process can advantageously be carried out outside of the assembly line of the functional part.
Because the fuel injector is designed as so-called “side-feed injector”, the advantage of laterally integrating a supply duct at an induction pipe or immediately at the cylinder head of an internal combustion engine ensues so that additional fuel distributors and complex connectors can be dispensed with.
As a general principle, such a valve type offers itself to be mounted directly on the cylinder head, and therefore to be used, for example, as an injector for injecting a fuel directly into a combustion chamber.
For producing a fixed connection of the two subassemblies, it is particularly advantageous to select a plastic for the injection molding which has its melting point at a higher temperature as the plastic used for the connecting part. Thus, it is guaranteed that a polymeric compound is formed between the two plastics. It is an advantage to execute a labyrinth seal at the outer circumference of the connecting part. In this manner, during the injection molding, a heat distribution is achieved which makes a good melting on possible. Moreover, it is achieved that a high mechanical stability in this region and, consequently, of the entire fuel injector, as well as a good tightness are guaranteed.
It is beneficial for the functional part performing all important valve functions to have very short design. Thus, a simplified access to the component parts of the fuel injectors which are to be adjusted results in an advantageous manner. Resulting primarily are markedly shortened paths for the mounting of measuring arrangements such as probes for measuring the lift of the valve needle or tools for adjusting the dynamic spray quantity at the adjusting element.
In an advantageous manner, it is possible to make a very substantial variation of the electrical connecting elements at the functional part and the connecting part. Thus, it is always possible to execute the electrical connecting elements both at the functional part and at the connecting part in a form which is either similar to that of a plug or of a bushing, or as a combination of both ways.
REFERENCES:
patent: 3913537 (1975-10-01), Ziesche et al.
patent: 4946107 (1990-08-01), Hunt
patent: 4957241 (1990-09-01), Roger
patent: 4959027 (1990-09-01), Muzslay
patent: 5044563 (1991-09-01), Mesenich
patent: 5156124 (1992-10-01), Tomojiro et al.
patent: 5275341 (1994-01-01), Romann et al.
patent: 5758826 (1998-06-01), Nines
patent: 6012655 (2000-01-01), Maier
patent: 6027049 (2000-02-01), Stier
patent: 34 39 672 (1986-04-01), None
patent: 196 31280 (1998-02-01), None
patent: 197 12 591 (1998-10-01), None
Fuchs Heinz
Hafner Udo
Noller Klaus
Staacke Albert
Evans Robin O.
Kenyon & Kenyon
Robert & Bosch GmbH
Scherbel David A.
LandOfFree
Fuel injector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fuel injector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel injector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2459468