The present invention relates generally to a fuel injector positioning member.

BACKGROUND OF THE INVENTION

On an engine block, fuel injectors are inserted in deep well wherefrom protrudes outside the well the injector's head provided with a cylindrical tubular connection member adapted to receive high pressure fuel pipe. A yoke member screwed on the engine block finally fixes the injector in place. The angular position of the injector, and therefore alignment of the connection member, set by the yoke is no longer sufficiently accurate to match nowadays stricter performances and robustness requirements.

SUMMARY OF THE INVENTION

It is an object of the invention to resolve or at least mitigate the above mentioned problem by providing a locating member adapted to precisely position a fuel injector onto the engine block of an internal combustion engine. The locating member comprises a planar portion adapted to be fixed in surface contact on a face of the engine block, said planar portion being provided with an engine block positioning feature for positioning said locating member onto said face of the engine block and, an injector positioning feature adapted to position the fuel injector relative to the locating member so that, the fuel injector can be precisely positioned relative to the engine block.

Also, the engine block positioning feature comprises at least two openings adapted to be complementary engaged onto engine valve guide tubes protruding from the face of the engine block.

Also, the injector positioning feature is a fork-like portion protruding perpendicularly from the planar portion, said fork-like portion being adapted to receive in a complementary engagement a pipe connection member extending from the body of the injector.

Particularly, the fork-like portion comprises two arms between which the pipe connection member is able to engage, the split distance between said two arms being equal to the width of the pipe connection member.

Also, the injector positioning feature comprises an edge perpendicular to the planar portion and adapted to be in contact against a flat face of the injector.

The invention also extends to a locating member as described in anyone of the preceding paragraph wherein said member is made by stamping, bending a metal sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is now described by way of example with reference to the accompanying drawings in which:

Figure 1 is a general isometric view of a top face engine block where a fuel injector is positioned thanks to a first positioning member made as per the invention.

Figure 2 is a front view of the general view of figure 1.

Figure 3 is similar to figure 1 with an alternative to the first positioning member.

Figure 4 is general isometric view of a top face engine block where a fuel injector is positioned thanks to a second positioning member made as per the invention.

Figure 5 is a side view of the general view of figure 4.

Figure 6 is similar to figure 4 with an alternative to the second positioning member. DESCRIPTION OF THE PREFERRED EMBODIMENTS

A top view of an engine block 10 is presented on figure 1 where a top face 12 of the engine block 10 is planar XY, the figure focusing on the region of the top face 12 where a fuel injector 14 protrudes outside a deep well 16, along a main axis Z normal to the plan XY of the face 12, wherein it is inserted.

Four engine valve guide tubes 18 also extend perpendicularly to the top face

12 forming a rectangle at the centre of which is the head 20 of the injector 14. The figure illustrates an intermediate stage of the assembly of the engine and, the person skilled in the art knowns that when assembly is completed valves are engaged inside said four tubes 18 their stem upwardly protruding from the visible openings of the tubes 18 and being provided at their extremities with a spring seat. Valve springs are engaged around the tubes 18 and are compressed between the engine block 10 and said spring seat so that the valves are permanently upwardly biased by the springs. The orientation of the figures is chosen to ease and clarify this description in a non-limiting manner, therefore, terms such as "upwardly" are used to illustrate the description without any intent to limit the scope of the invention.

The head 20 of the injector 14 protruding from the well 16 is provided with a pipe connection member 22 that is cylindrical and extends paralleled to the top face 12, perpendicular to the main axis Z.

In this intermediate assembly stage, the injector 14 is angularly maintained in a fixed orientation relative to the engine block 10 thanks to a locating member 24 provided on one hand with an engine block locating portion 26 for positioning said locating member 24 onto said top face 12 of the engine block and, on the other hand, an injector locating portion 28 for position the fuel injector 14 relative to the locating member 24. Therefore, the locating member 24 acts as an intermediate positioning feature angularly maintaining the injector 14 relative to the engine block 10.

Although the locating member 24 could be made as per many different manufacturing processes, such as a machined block or a welded assembly, a preferred way is shown on the figures, the locating member 24 being cut and stamped and bent to shape starting from a flat metallic piece of about 1mm thickness.

The engine block locating portion 26 is planar and it is provided with two distinct openings 30, 32, which inter-distance D is equal to the inter-distance D between two valve guide tubes 18. As shown on the figures the engine block locating portion 26 is engaged over two tubes 18 and it is in surface contact against the top face 12 of the engine block. Also, figures 1 and 4 differ from figures 3 and 6 in that the engine block locating portion 26 of figures 1 and 4 is laterally arranged relative to the injector 14 while, in figures 3 and 6, it is in front of the injector. Here again, the front side or lateral side of the injector are arbitrarily chosen relative to the pipe connection member 22. In non-represented embodiments, the engine block locating portion 26 could be provided with more than two openings, three or four for instance, said portion 26 having a L-shape or a U- shape or even a closed rectangular shape provided with a large central opening enabling the injector head 16 to extend outside the well. Furthermore, the openings that are presented as complete circular holes pierced in the planar portion could be only partial indentations or notches provided on the edge of a planar portion and enabling complementary engagement of the tubes 18.

In combination with any of the alternatives of engine locating portions 26 presented above, are now described two alternatives of the injector locating portion 28.

In reference to figures 1, 2 and 3 the injector locating portion 28 comprises a fork-like portion 34 perpendicularly protruding along the main axis Z, said forklike portion 34 being integral to the engine block locating portion 26 as being simply bent at right angle relative to it. The fork- like portion 34 enables complementary engagement of the pipe connection member 22 between the two vertical arms 36 of the fork.

A second embodiment of the injector locating portion 28 is described in reference to figures 4, 5 and 6 and it comprises a tongue 38 integral to the engine block locating portion 26 and slightly bent over its plan XY, the tongue 38 extending from the planar portion in the direction of the injector 14 toward a distal linear edge 40. As shown on the figure, the edge 40 is in linear contact against a vertical face of the injector 14, thus forbidding angular pivoting of the injector 14.

On the embodiment represented, the tongue 38 is bent in a Z-shape, the edge 40 being formed by the thickness of the metal plate. In non-represented embodiments, the tongue 38 can be any other shape such as a L-shape where the vertical leg of the L would lie against said vertical face of the head 14 of the injector.

LIST OF REFERENCES

XY plan of the top face

Z main axis

D inter-distance between valve tubes 10 engine block

12 top face of the engine block

14 fuel injector

16 well

18 valve guide tube

20 head of the injector

22 pipe connection member

24 locating member

26 engine block locating portion

28 injector locating portion

30 opening

32 opening

34 fork- like portion

36 arms of the fork

38 tongue

40 edge