EP1703121A1

EP1703121A1 - Clip and fuel injector assembly

Info

Publication number: EP1703121A1
Application number: EP05004044A
Authority: EP
Inventors: Paolo Campanella; Antonio Liuzzi; Salvatore Varchetta
Original assignee: Siemens VDO Automotive SpA
Current assignee: Continental Automotive Italy SpA
Priority date: 2005-02-24
Filing date: 2005-02-24
Publication date: 2006-09-20

Abstract

A fuel injector assembly comprises a fuel injector 1, a fuel rail 2 and a clip 15. The clip 15 is suitable for connecting and positioning a fuel injector 1 to a fuel rail 2. The clip comprises first recess 9 being designed for retaining a fuel injector 1 and comprises a second recess 10 that communicates with the first recess 9. The second recess 10 is designed for retaining an injector guide 13 which is connected to the fuel injector 1. The clip further comprises a third recess 11 being designed for retaining a cup guide 14 of the cup 3 of the fuel rail 2.

Description

The invention relates to a clip that is suitable for connecting and positioning a fuel injector to a fuel rail. The invention further relates to a fuel injector assembly comprising a fuel injector, a fuel rail and a clip for connecting and positioning the fuel injector into the fuel rail. A clip of this kind is particularly suitable for use in a fuel supply device of an internal combustion engine.
In order to keep pressure fluctuations during the operation of the internal combustion engine at a very low level, internal combustion engines are supplied with a fuel accumulator to which the injection valves are connected and which has a relatively large volume. Such a fuel accumulator is often referred to as a fuel rail.
Known fuel rails comprise a hollow body with recesses in form of cups, where the fuel injection valves are arranged. The connection of the fuel injection valves to the fuel rail, that supplies the fuel from a fuel tank via a low or high pressure fuel pump, needs to be very precise to get a correct injection angle.
The object of the invention is to create a clip which is simple and at the same time ensures a precise connection and position between a fuel injector and a fuel rail.
It is furthermore the object of the invention to create a fuel injector assembly, that ensures a precise dosing of fuel.
The object is achieved by the features of the independent claims. Advantageous embodiments of the invention are given in the sub-claims.
The invention is in accordance with the first aspect distinguished by a clip that is suitable for connecting and positioning a fuel injector to a fuel rail. The clip comprises a first recess being designed for retaining a fuel injector and a second recess that communicates with the first recess being designed for retaining an injector guide which is connected to the fuel injector. Further, the clip comprises a third recess being designed for retaining a cup guide of a cup of the fuel rail.
Such a clip has the advantage of being able to achieve a narrower position of the fuel injector to the cup. This guarantees a more accurate angular positioning of the fuel injector in the fuel rail and furthermore, an optimum of the spray targeting point and the spraying angle. The clip can ensure a high quality connection between the fuel injector and the fuel rail. The function of the clip is on the one hand a anti-twist device and on the other hand a connecting function. Further, it is very easy to manufacture the clip. The very simple design makes it possible to produce the clip with fewer process steps.
In an advantageous embodiment of the clip the first recess and the second recess are designed in a way that makes it possible to push the fuel injector and the first recess by elastic deformation. Such a design ensures a very simple installation of the clip. In this respect the design has the advantage that the clip could be installed in a radial direction to the fuel injector.
In a further advantageous embodiment of the clip the third recess of the clip is designed with a rectangular cross-section. A rectangular cross-section is very easy to manufacture and ensures a precise connection to the cup guide of the cup of the fuel rail.
In a further advantageous embodiment of the clip the third recess of the clip is arranged in an angular position to the second recess. The angular position of the third recess to the second recess has the advantage that the third recess can retain the cup guide of the cup of the fuel rail very easily.
In a further advantageous embodiment of the clip the angle between the third recess and the second recess of the clip is about 90°. That is a very advantageous design for retaining the cup guide in the third recess.
In a further advantageous embodiment of the clip, the clip comprises a fourth recess that communicates with the third recess and the third recess being further designed for retaining the cup guide. That design has the advantage that the clip could be installed in a axial direction to the fuel injector.
In a further advantageous embodiment of the clip, the fourth recess is designed with a trapezoidal cross-section. A trapezoidal cross-section is very easy to manufacture.
In a further advantageous embodiment of the clip, the fourth recess is designed in a way that makes it possible to push the cup guide in the third recess by elastic deformation. Such a design ensures a very simple installation of the clip, especially in axial direction.
In a further advantageous embodiment of the clip, the clip is made out of stainless steel. The use of the clip being made out of stainless steel ensures a higher capacity of resistance to wear and corosion. Such a material is widely and fairly cheaply available.
The invention is in accordance with the second aspect distinguished by a fuel injector assembly, comprising a fuel injector with a housing, a valve body, at least one nozzle, an injector guide and a connection area to a fuel rail. The fuel injector assembly further comprises a fuel rail having a cup with a cup guide and further comprises a clip in accordance with one of the preceding claims for connecting and positioning the fuel injector in the cup of the fuel rail. Such a fuel injector assembly has the advantage that the fuel injector is very precisely connected and positioned to the cup of the fuel rail. Furthermore, the spray targeting point and the spraying angle is extremely precise.
Exemplary embodiments of the invention are explained in the following with the aid of schematic drawings. These are as follows:

Figure 1:: an internal combustion engine with a fuel rail,
Figure 2:: a fuel injector arranged in a cup,
Figure 3:: a clip,
Figure 4:: a top view of the clip,
Figure 5:: a side view of the clip,
Figure 6:: a front view of a first embodiment of the clip, and
Figure 7:: a front view of a second embodiment the clip.

Elements of the same design or function that occur in different illustrations are identified by the same reference character.
A fuel feed device is assigned to an internal combustion engine (Figure 1). It includes a fuel tank 4 that is connected via a first fuel line to a pressure pump 5. The output end the pressure pump 5 is connected to an inlet of a fuel rail 2. Fuel injectors 1 are actively connected to the fuel rail 2. The fuel is this fed to the fuel injectors 1 via the fuel rail 2. The fuel injectors 1 have a sealed connection to the fuel rail 2.
Figure 2 shows a fuel injector assembly, comprising a fuel injector 1, a clip 15 and a cup 3. The fuel injector 1 is arranged in the cup of the fuel rail 2 and connected and positioned to the cup by the clip 15. The fuel injector that is suitable for injecting a fuel into a gasoline engine or that also may be suitable for injecting fuel into a diesel engine, comprises a housing, a valve body, at least one nozzle, an injector guide 13 and a connection area 16 to the fuel rail. The injector guide 13 is arranged in the connection area 16 of the fuel injector 1. The injector guide 13 comprises a guidance in form of a cap. Alternative embodiments of the injector guide 13 are possible. The cup 3 is connected to the fuel rail 2 and comprises a cup guide 14 in form of a nose. The nose is, for example, embodied with a rectangular cross-section. The cup guide 14 meshs in the third recess 11 of the clip 15.
Figure 3 shows the clip of the fuel injector assembly in Figure 2. The clip 15 further comprises a first recess 9 and a second recess 10. The first recess is being designed for retaining the fuel injector 1. In a prefered embodiment the first recess 9 has the geometrical shape of the fuel injector 1 in the aera of the clip collet. The second recess 10 communicates with the first recess 9 and is being designed for retaining the injector guide 13. In a prefered embodiment the second recess 10 has the geometrical shape of the injector guide 13. The fuel injector 1 is fitted by the first recess 9, especially in the connection area 16. The injector guide 13 is fitted by the second recess 10 of the clip 15. The third recess 11 is, in a preferred embodiment, designed with a rectangular cross-section. In other advantageous embodiments different designs of the third recess 11 are possible. Furthermore, the first recess 9 and the second recess 10 are designed in a way that makes it possible to push the fuel injector in the first recess 9 by elastic deformation. This design has the advantage that the clip may be installed in a radial direction to the fuel injector.
The first recess 9 and the second recess 10 are in a prefered embodiment arranged in an angular position to the third recess. The angle between the third recess and the second recess is about 90°, but in other advantagous embodiments are angles of 0° up to 90° possible.
Figure 4 shows the top view of the clip shown in Figure 2 and Figure 3. Figure 5 shows the side view of the clip and the angle between the third recess and the second recess is about 90°.
Figure 6 shows the front view of the clip shown in Figures 2 to 5. Third recess 11 of the clip 15 is designed with a rectangular cross-section. The clip 15 will be preferably installed after the installation of the fuel injector 1 to the cup 3. The clip will be pushed in radial direction to the fuel injector and retains the cup guide 14 in the third recess 11, the injector guide 13 in the second recess 10 and the fuel injector 1 in the first recess 9.
Figure 7 shows the the front view of th clip with a fourth recess 12. The fourth recess 12 communicates with the third recess 11. The third recess is being further designed for retaining the cup guide 14. In that exemplary embodiment the fourth recess 12 shows a trapezoidal cross-section. The advantage of the trapezoidal cross-section 12 is that the fourth recess can be designed in a way that makes it possible to push the cup guide in the third recess 11 by elastic deformation. In relation to that the clip is installed to the fuel injector 1 and then the preinstalled clip and fuel injector will be installed in axial direction to the cup 3.
In all embodiments of the clip 15, the clip 15 may be made out of stainless steel, which is especially advantageous, if it needs to be robust against corrosion. The clip is then preferably made out of stainless steel 1.4310. If the clip is made out of spring used for springs it may have very good elastic properties.

Claims

Clip (15) that is suitable for connecting and positioning a fuel injector (1) to a fuel rail (2) comprising a first recess (9) being designed for retaining a fuel injector (1), comprising a second recess (10) that communicates with the first recess (9) being designed for retaining an injector guide (13) which is connected to the fuel injector (1) and comprising a third recess (11) being designed for retaining a cup guide (14) of a cup (3) of the fuel rail (2).
Clip in accordance with claim 1,
in that the first recess (9) and the second recess (10) are designed in a way, that makes it possible to push the fuel injector (1) in the first recess (9) by elastic deformation.
Clip in accordance with one of the preceding claims,
in that the third recess (11) is designed with a rectangular cross section.
Clip in accordance with one of the preceding claims,
in that the third recess is arranged in a angular position to the second recess.
Clip in accordance with claim 4,
in that the angle between the third recess and the second recess is about 90°.
Clip in accordance with one of the preceding claims, comprising a fourth recess (12), that communicates with the third recess (11) and the third recess being further designed for retaining the cup guide (14).
Clip in accordance with claim 3,
in that the fourth recess (12) is designed with a trapezoidal cross section.
Clip in accordance with claims 4 or 5,
in that the fourth recess (12) is designed in a way, that makes it possible to push the cup guide (14) in the third recess (11) by elastic deformation.
Clip in accordance with one of the preceding claims, being made out of stainless steel.
A fuel injector assembly, comprising a fuel injector (1) with a housing, a valve body, at least one nozzle, an injector guide (13) and a connection area (16) to a fuel rail (14), further comprising the fuel rail (2) having a cup (3) with a cup guide (14) and further comprising a clip (15) in accordance with one of the preceding claims for connecting and positioning the fuel injector (1) in the cup(3) of the fuel rail (14).