Collecting pressure line for a fuel injection system of an internal combustion engine

Abstract

A collecting pressure line (1) for a fuel injection system of an internal combustion engine has a flow-traversable interior (9). The collecting pressure line (1) has at least one injector that is flow-traversable with the aid of a throughflow opening (8). Fluid present in the collecting pressure line (1) is injected with the aid of the injector into a combustion chamber of the internal combustion engine. An elastic member (10) is formed in the interior (9) and is designed to be flow-traversable while bearing against a line inner wall (15) and spaced apart from the throughflow opening (8).

Claims

1. A collecting pressure line for a fuel injection system of an internal combustion engine, the collecting pressure line having a flow-traversable interior (9), the collecting pressure line having at least one injector that is flow-traversable with the aid of a unilaterally closed throughflow opening so that fluid present in the collecting pressure line is injected with the aid of the injector into a combustion chamber of the internal combustion engine, and an elastic means being in the interior, wherein the elastic means is flow-traversable while bearing against an inner surface of the collecting pressure line and being spaced by a spacing from the throughflow opening.

2. The collecting pressure line as claimed in claim 1, further comprising a nonelastic sleeve is arranged in the interior to form the spacing between the elastic means and the throughflow opening.

3. The collecting pressure line of claim 2, wherein the sleeve, the elastic means and the throughflow opening are flow-traversable.

4. The collecting pressure line of claim 2, wherein the sleeve is immovably connected to the connecting pressure line.

5. The collecting pressure line of claim 2, wherein the sleeve has further throughflow openings at spaced apart positions over its circumference.

6. The collecting pressure line of claim 5, wherein the sleeve has a circumferential groove communicating with the throughflow opening.

7. The collecting pressure line of claim 2, wherein an end of the sleeve facing the elastic means has a receiving ring with a diameter that is at most equal to an inside diameter of the elastic means and less than an outside diameter of the sleeve.

8. The collecting pressure line of claim 2, wherein an outside diameter of the elastic means is at least equal to an inside diameter of the collecting pressure line.

9. The collecting pressure line of claim 2, wherein an outside diameter of the sleeve is at most equal to an inside diameter of the collecting pressure line.

10. The collecting pressure line of claim 1, wherein the elastic means is formed from a fuel-resistant material.

11. The collecting pressure line of claim 1, wherein the elastic means comprises annular or tubular sections.

12. The collecting pressure line of claim 1, wherein the elastic means comprises annular O-rings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective illustration showing collecting pressure lines according to the invention of a fuel injection system for an internal combustion engine.

(2) FIG. 2 is a longitudinal section showing the collecting pressure line according to the invention in a first exemplary embodiment.

(3) FIG. 3 is a longitudinal section showing the collecting pressure line according to the invention in a second exemplary embodiment.

DETAILED DESCRIPTION

(4) A collecting pressure line 1 according to the invention is shown in FIG. 1 and is used in a fuel injection system 2 for an internal combustion engine having two banks of cylinders. The collecting pressure line 1 is a distributor often called a fuel rail or a fuel distributor. The collecting pressure line 1 has flow-traversable receiving openings 3 according to a number of the cylinders to be supplied. Each flow-traversable receiving opening 3 is equipped with an injector (not illustrated in further detail). In the illustrated embodiment, the collecting pressure line 1 has three receiving openings 3, and therefore three cylinders of the internal combustion engine are supplied with fuel via the collecting pressure line 1. The collecting pressure line 1 also could be designed to supply two, four or more injectors and accordingly would have two, four or more receiving openings 3.

(5) The collecting pressure line 1, as central hydraulic component, interconnects a fuel pump (not illustrated in further detail) in the form of a high-pressure pump and the injectors. Compressed fuel is present in the collecting pressure line 1 and, according to an injection time of the internal combustion engine, is made available to the corresponding injector(s). The fuel passes via the injector into a combustion chamber of the internal combustion engine.

(6) The collecting pressure line 1 is a hollow tube in which the fuel is present and can flow therethrough. A first end 4 of the collecting pressure line 1 in the axial direction along its longitudinal axis 14 has a flow-traversable connection 5 that can be connected to the fuel pump such that flow can pass through. A second end 6 facing away from the first end 4 is closed in a non-flow-traversable manner.

(7) The flow-traversable receiving openings 3 are formed with the aid of cylindrical tubes 7 in these exemplary embodiments. Each tube 7 is connected to the collecting pressure line 1 to be flow-traversable with the aid of a unilaterally closed throughflow opening 8 formed in the collecting pressure line 1. Thus, each tube 7 is assigned a throughflow opening 8.

(8) The collecting pressure line 1 has an interior 9 with a volume-reducing and pressure pulsation-damping means 10 (referred to herein after as elastic means 10) that is hollow and thus flow-traversable.

(9) The pressure pulsation-damping means 10 is elastic and is referred to hereinafter simply as an elastic means 10. In the embodiment of FIG. 2, the elastic means 10 is formed from an elastic material in the form of an elastomer. When using plastics, care must be taken to ensure that the plastic is fuel-compatible, in other words fuel-resistant, and no reaction with the fuel can occur.

(10) In the first embodiment, the elastic means 10 is defined by rings in the form of hollow cylinders that are arranged next to one another in a flow-traversable manner. In each case, a sleeve 11 having further throughflow openings 12 is arranged in the region of the throughflow opening 8. Thus, in each case one elastic means 10 is between two sleeves 11 that are arranged immovably in the collecting pressure line 1. A spacing A of the elastic means 10 from the throughflow opening 8 is formed with the aid of the sleeve 11.

(11) The sleeve 11 preferably is formed from metal, but could be configured from a plastic, and preferably from a nonelastic plastic. In this first embodiment, the elastic 10 has four rings arranged next to one another.

(12) The second embodiment is illustrated in FIG. 3 and has the elastic means 10 in the form of flow-traversable sealing elements in the form of so-called O-rings that are arranged next to one another. The individual O-rings 10, like the individual rings of the first embodiment, can be connected to one another in an integrally bonded manner, or they can be arranged next one another in a sealing manner. The elastic means 10 also could be formed in one piece.

(13) In both exemplary embodiments, the elastic means 10 bears against an inner surface 15 of the collecting pressure line 1, and is substantially traversed by the flow of the fuel, with a further interior 16 of the elastic means 10 being flow-traversable. Fuel can be guided from the further interior 16 into a circumferential groove 17 of the sleeve 11 via the further throughflow openings 12 such that the fuel necessary for injection can flow into the throughflow opening 8 and thus into the injector even independently of an exact positioning of the further throughflow opening 12 above the throughflow opening 8.

(14) To provide bearing against the collecting pressure line 1, an outside diameter DAM of the elastic means 10 is equal to an inside diameter DI of the collecting pressure line 1. It could also be greater, since the elastic means 10 is designed to be compressible. However, it should not be so large that the elastic means 10 still is configured for the throughflow of sufficient fluid for the internal combustion engine. An outside diameter DAH of the sleeve 11 is precisely equal to the inside diameter DI of the collecting pressure line 1 such that it can be readily joined.

(15) The fuel that flows through the collecting pressure line 1 can be pure fuel or an emulsion consisting of fuel and for example water.

(16) Pressure pulsations occur in the collecting pressure line 1 as a result of the injection process. To securely support the collecting pressure line 1 there is formed alongside each tube 7 a respective supporting element 13 for fixing the collecting pressure line 1 on the internal combustion engine. The supporting element 13 could also be formed at other points of the collecting pressure line 1, although, given an opening and closing of the injector and the associated body vibrations, the arrangement of the supporting element 13 close to the tube 7 produces better support of the collecting pressure line 1.