Fluid handling – Systems – System with plural openings – one a gas vent or access opening
Reexamination Certificate
1999-10-06
2001-06-05
Rivell, John (Department: 3753)
Fluid handling
Systems
System with plural openings, one a gas vent or access opening
C123S516000, C141S059000
Reexamination Certificate
active
06240958
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fuel supply system for automobiles with a fuel tank to which are connected a filler pipe and at least one vent for venting the tank during operation of the automobile and one vent for venting the tank during refueling of the tank.
2. Description of the Related Art
An essential component of a fuel supply system is the fuel tank which contains the fuel needed for supplying the internal combustion engine. Connected to the fuel tank are a filler pipe for refueling and at least one vent for venting the tank during operation and a vent for venting the tank during refueling. Fuel tanks are available as containers of metal and of synthetic material.
The volume of fuel removed from the fuel tank during operation of the internal combustion engine must be replaced by air in order to avoid a pressure difference. This is effected through the operation vent. For this purpose, one or more operation vent lines, such as hoses or pipes, are provided on the fuel tank for connecting the fuel tank to the ambient air. This is usually effected by an activated carbon filter which is mounted in the vent line and neutralizes the gasoline vapors.
In addition to the operation vent, a refueling vent is provided on the fuel tank. This vent composed of one or more lines, such as hoses or pipes, has the purpose of conducting out of the fuel tank the gas volume displaced by the inflowing fuel during refueling. As a rule, the displaced gases are neutralized in an activated carbon filter and are then discharged into ambient air.
In fuel supply systems of the conventional type, the individual operation vent lines and refueling vent lines are located individually outside of the fuel tank. Consequently, a separate connection to the fuel tank with an opening in the wall of the fuel tank is required for each line. Another connection opening is required for the filler pipe. This is cumbersome with respect to manufacturing technology. Moreover, high requirements must be made of the tightness of the connections in order to ensure the operational safety of the fuel supply system.
In addition, the connecting and sealing locations are potential weak points for an escape of fuel gases by permeation, i.e., when fuel gases permeate or diffuse through the sealing material.
This undesired process also occurs at the lines, namely, at the lines for venting during operation and for venting during refueling as well as at the filler pipe. It is disadvantageous in this connection that a large outer surface area of the lines is present through which the gas can diffuse and reach ambient air from the interior of the fuel supply system.
In conventional systems, high-grade materials and complicated sealing systems are used for reducing the permeation of a fuel supply system.
SUMMARY OF THE INVENTION
Therefore, it is the primary object of the present invention to improve a fuel supply system with respect to manufacturing and operational technology, and particularly to prevent permeation.
In accordance with the present invention, the operation vent line and/or the refueling vent line are components of a multiple-duct line.
Consequently, in accordance with the present invention, one or more lines, such as the operation vent line and the refueling vent line, extend together within the multiple-duct line. The multiple-duct line may operate as an operation vent or as a refueling vent.
As a result of the configuration according to the present invention, openings or connection points in the fuel tank and, thus, sealing points are minimized. Consequently, the invention makes it possible to reduce to a single central opening the otherwise necessary individual openings for operation and refueling vent lines.
Another advantage is the fact that less high-grade materials can be used for the lines which are located within the multiple-duct line. A particularly high permeation tightness is not required in these lines. Only the multiple-duct line, whose outer periphery is in direct contact with the environment, must be composed of higher-grade, diffusion-resistant materials. The use of metal pipes is a particular option in this connection.
In accordance with a particularly advantageous embodiment of the basic concept of the present invention, the filler pipe is also incorporated in the multiple-duct line.
As a result of this feature, the number of required openings in the fuel tank is further reduced and the tightness increased.
In accordance with another feature of the present invention, a compensation container is integrated in the multiple-duct line. This compensation container is preferably produced by a radial expansion of the multiple-duct line. This can be carried out in an economical manner by hydraulic shaping.
The compensation container provides a compensation volume for the thermal expansion of the fuel in the fuel tank. Consequently, it is possible to completely fill the fuel tank. In addition to serving as an expansion compensator, liquid or fuel droplets which are conducted or entrained in the volumetric gas flow can be separated in the compensation container.
In accordance with a useful feature, a displacement compensator is integrated in the multiple-duct line. This displacement compensator assumes an uncoupling function. This makes it possible to compensate any displacements occurring during operation, for example, as a result of relative displacements during a crash or through temperature-related length extensions.
The advantages of the invention are particularly significant in those fuel supply systems which include multiple-chamber tanks in which each fuel chamber is equipped with an operation vent.
The function of an operation vent line can also be assumed by the multiple-duct line. In that case, venting takes places through the free cross-section in the annular space between the remaining lines located in the multiple-duct line.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
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patent: 4722454 (1988-02-01), Fischer
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patent: 5538039 (1996-07-01), Harde et al.
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patent: 5704337 (1998-01-01), Stratz et al.
patent: 5964204 (1999-10-01), Freeland
patent: 5996622 (1999-12-01), Cimminelli et al.
Ewerszumrode Andreas
Streubel Wolfgang
Topker Dieter
Benteler AG
Kueffner Friedrich
Rivell John
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