Title of Invention

PROCESS FOR THE MANUFACTURE OF A FUEL INJECTION VALVE AND FUEL INJECTION VALVE

Abstract Process for the Manufacture of a Fuel Injection Valve and Fuel Injection Valve i The invention is with regard to a fuel injection valve with a valve longitudinal axis (10), with a fuel inlet nozzle (41), with a valve closing body that can be moved along the valve's longitudinal axis (10) and that works together with a valve seat provided at a valve seat body and with at least one spray opening downstream from the valve seat. The fuel inlet nozzle (41) comprising of a thin-walled pipe (44) runs, beginning from an entry port (60), with an upstream section (62), at an angle (a) to the valve's longitudinal axis (10), this angle being greater than 0° and less than/equal to 90°. The fuel inlet nozzle (41) finally ends with its downstream section (63) at the valve's longitudinal axis (10). The fuel injection valve is particularly suited for use in fuel injection systems of fuel-mixture compressing, externally ignited internal combustion engines. (Figure 3)
Full Text

Process for the Manufacture of a Fuel Injection Valve and Fuel Injection Valve
Prior Art
The invention emanates from a process for the manufacture of a fuel injection valve according to the genre of Claim 1 and emanates as well from a fuel injection valve according to the genre of Claim 5.
Figure 1 illustrates a fuel injection valve established in prior art, which has a classical top-feed design, characterised in that all flow-guiding components of the injection valve stretch flush along the valve's longitudinal axis, whereby the flow inlet is connected to a connecting piece of a fuel distributor and the fuel outlet is directed downstream from the seat into a suction pipe or directly into a combustion chamber of an internal combustion engine.
A fuel injection valve which can be operated electro-magnetically in the traditional manner is already established in DE 21 53 286 A1. The injection valve has an inlet nozzle that is located offside from the valve's longitudinal axis. The injection valve also has a casing body in which all relevant valve components are built so that fuel between the inlet nozzle and a fuel outlet can be fed under pressure to the valve seat which works together with a valve closing body. The casing body is covered with a cap-like closing body at the supply side that, apart from the inlet nozzle, also has an outlet connection flush to the valve's longitudinal axis for

excess fuel and an electrical wrap connection. The closing body is held tightly at the casing body by means of a flanged rim of the casing body that grasps the closing body. A sealing ring is provided, apart from this, in the connecting area between the closing body and the casing body.
Advantages of the Invention
The advantage of the process, in accordance with the invention, for manufacture of a fuel injection valve with characterising features of Claim 1 is that fuel injection valves with low headroom for constricted conditions e.g. in motor cycles, can be manufactured in an especially simple and cost-effective manner. Of particular advantage is that the fuel injection valve, in accordance with the invention, with characterising features of Claim 5, is present in an actual function part of the injection valve, in an already completely adjusted condition with regard to the stroke of the valve part that can be moved in an axial direction as well as the dynamic and static flow quantities so that a subsequent, problem-free assembly of an angled fuel inlet nozzle that, in fact, deviates from the alignment of the valve's longitudinal axis, can take place in a connecting piece of the injection valve at the function part through a fixed connection.
Fuel injection valves that have fuel inlet nozzles, whose angle to the valve's longitudinal axis can be variable, between 0° and 90°, can be manufactured in a particularly advantageous manner.
Furthermore, an inlet nozzle designed in this manner and angled at one side very simply offers the possibility of precise positioning of the injection valve and of a simplified twist fixing respectively.

Advantageous further development and improvements of the process specified in Claim 1 and of the fuel injection valve specified in Claim 5 respectively are possible through measures indicated in the sub claims.
Ideally, the fuel inlet nozzle should be provided with a saw-toothed profile at its upstream end so that a simple connection to a fuel-supplying hose, that is pushed on to the saw-tooth profile, and to a hose clamp is enabled. Other sealing measures such as O Rings can be dispensed with in this manner.
Drawing
An exemplary embodiment of the invention is presented in a simplified manner in the drawing and is subsequently described in greater detail. Figure 1 illustrates a fuel injection valve in accordance with prior art with top-feed supply, with fuel, running flush to the valve's longitudinal axis. Figure 2 illustrates a fuel inlet nozzle with hose connection possibilities and likewise fuel supply that is flush to the valve's longitudinal axis. Figure 3 illustrates a fuel inlet nozzle with hose connection possibilities and fuel supply angled at approximately 90° to the valve's longitudinal axis.
Description of the Exemplary Embodiment
Before describing the steps of the manufacturing process of a fuel injection valve in accordance with the invention by means of Figures 2 and 3, the basic structure of a fuel injection valve of prior art that is designed as the so-called top-feed injection valve, will be described in greater detail by means of Figure 1.
The valve illustrated as an example in Figure 1, which can be operated electro-magnetically in the form of an injection valve in fuel injection systems of fuel-mixture compressing, externally ignited internal combustion engines, has an

essentially tubular core 2 that is surrounded by a magnet coil 1 and serves as an internal pole and, to some extent, as a fuel passage. The magnet coil 1 is completely surrounded in the direction of the circumference by an external, sleeve-shaped and tiered e.g. ferromagnetic valve shell 5 that presents an external magnetic circuit component serving as an external pole. The magnet coil 1, the core 2 and the valve shell 5 together form an electrically excitable actuating element.
While the magnet coil 1 that is embedded in a coil body 3 surrounds a valve sleeve 6 from the outside, the core 2 is inserted in an internal opening 11 of the valve sleeve 6 that runs concentric to the valve's longitudinal axis 10. The e.g. ferritic valve sleeve 6 stretches longitudinally and has thin walls. Opening 11 serves, among other things, as a guide opening for a valve needle 14 that can be moved in an axial direction along the valve's longitudinal axis 10. The valve sleeve 6 stretches in an axial direction e.g., over approximately half the total axial stretch of the fuel injection valve.
Apart from the core 2 and the valve needle 14, a valve seat body 15 is, furthermore, located in opening 11, which is affixed to the valve sleeve 6 e.g. by means of a welded seam 8. The valve seat body 15 has a fixed valve seat surface 16 that serves as the valve seat. The valve needle 14 is composed of, for example, a tubular armature section, a likewise tubular needle section 18 and a spherical valve closing body 19, whereby the valve closing body 19 is firmly connected to the needle section 18 by means of a welded seam. A pot-shaped injection breaker plate 21, for example, is located downstream from the front side of the valve seat body 15, whose clamping edge 20 that is curved according to the circumference, is directed upwards, against flow direction. The fixed connection between the valve seat body 15 and the injection breaker plate 21 is e.g. realised by a circular sealed welded seam. One or several transverse openings 22 is/are provided in the needle section 18 of the valve needle 14 so

that fuel flowing along the armature section 17 in an internal longitudinal bore 23 can emerge outside and fuel at the valve closing body 19 e.g. along flat portions 24 can flow up to the valve seat 16.
Operation of the injection valve takes place electro-magnetically in an established manner. The electro-magnetic circuit with magnet coil 1, the internal core 2, the external valve shell 5 and the armature section 17 serves to move the valve needle 14 in the axial direction and, therewith, to open against the spring force of a reset spring 25 acting at the valve needle 14 and to close the injection valve respectively. The armature section 17 is aligned to the core 2 with that end that faces away from the valve closing body 19.
The spherical valve closing body 19 works together with the conically shaped valve seat 16 of the valve seat body 15 that tapers in the flow direction and that is designed downstream from a guide opening in an axial direction in the valve seat body 15. The injection breaker plate 21 has at least one, for example, four spray openings 27 that are shaped by erosion, laser bores or die-cutting.
The insertion depth of the core 2 in the injection valve is, among other things, decisive for the stroke of the valve needle 14. One final position of the valve needle 14 in the case of a non-energised magnet coil 1 is thereby determined by the arrangement of the valve closing body 19 at the valve seat 16 of the valve seat body 15, while the other final position of the valve needle 14 in the case of an energised magnet coil 1 results from the arrangement of the armature section 17 at the downstream core end. Stroke adjustment takes place through axial shifting of the core 2 that is, for example, manufactured using a machining process such as lathe cutting. The core is subsequently connected firmly to the valve sleeve 6, corresponding to the desired position.

Besides a reset spring 25, an adjustment element in the form of an adjusting sleeve 29 is inserted into a flow bore 28 of core 2 that runs concentric to the valve's longitudinal axis 10 and that serves to supply fuel in the direction of the valve seat 16. The adjusting sleeve 29 serves to adjust the initial load of the reset spring 25 that is adjacent to the adjusting sleeve 29, which in turn pushes the valve needle 14 with its side that lies opposite, whereby an adjustment of the dynamic injection quantity too takes place by means of the adjusting sleeve 29. A fuel filter 32 is located in the valve sleeve 6 above the adjusting sleeve 29.
The injection valve described up to this point is characterised by its especially compact design. These components form a pre-assembled, independent unit that will henceforth be referred to as function part 30. The function part 30, thus, essentially comprises of the electro-magnetic circuits 1, 2, 5 as actuator and a sealing valve (valve closing body 19, valve seat body 15) with its subsequent jet preparation element (injection breaker plate 21) as well as the valve sleeve 6 as a framework.
A second unit is created that is independent of function part 30 and that will henceforth be referred to as connecting piece 40. The connecting piece 40 is primarily characterised in that it contains the electric and hydraulic connection of the fuel injection valve. Using the process steps, in accordance with the invention, the compactness of the entire fuel injection valve should increase further, particularly through targeted shaping of the connecting piece 40, in that the headroom of the fuel injection valve can be reduced.
The connecting piece 40, which is designed partly as a plastic part, has a metallic fuel inlet nozzle 41 and a synthetic, tubular framework 42 which stabilises, protects and surrounds this fuel inlet nozzle 41. A flow bore 43 of pipe 44 of a fuel inlet nozzle 41, running concentric to the valve's longitudinal axis 10,

serves as a fuel inlet and has fuel flowing through it in an axial direction from the supplying end of the fuel injection valve.
A hydraulic connection of the connecting piece 40 and function part 30 is achieved in the completely assembled fuel injection valve by bringing together flow bores 43 and 28 of the two units in such a manner that an uninterrupted fuel flow is guaranteed. When assembling the connecting piece 40 to function part 30, a lower end 47 of the pipe 44 projects into the opening 11 of the valve sleeve 6 in order to increase the connecting stability. The synthetic framework 42 can be sprayed on to function part 30 so that the synthetic material directly envelops parts of the valve sleeve 6 as well as of the valve shell 5. Reliable sealing between function part 30 and the framework 42 of the connecting piece 40 is achieved, for example, by a labyrinth sealing 46 at the circumference of the valve shell 5.
An electrical connecting plug 56, which has also been sprayed on, forms part of the framework 42. The contact elements are connected electrically to the magnet coil 1 at its end which lies opposite the connecting plug 56.
Two connecting parts 40 with fuel inlet nozzles 41 are illustrated in part in Figures 2 and 3 in order to present the invention clearly. Figure 2, thereby, once again indicates that in the case of conventional, established fuel injection valves it is necessary that the fuel inlet nozzles 41 be located parallel and flush to the valve's longitudinal axis 10 in order to provide access to corresponding adjustment tools at any time for required adjustment measures within the valve.
The process for manufacture of a fuel injection valve, in accordance with the invention, is characterised in that it is possible to perceive a fuel inlet nozzle 41 at the fuel injection valve that, starting from an upstream entry port 60, runs at angle a to the valve's longitudinal axis 10, this angle being greater than 0° and less

than/equal to 90°. Figure 3 illustrates an exemplary embodiment in which the fuel inlet nozzle 41 runs at an angle a of 90° to the valve's longitudinal axis 10 in a first angled section 62. In this case, the entry port 60 is mounted at a level that runs parallel to the valve's longitudinal axis 10. Lastly, the fuel inlet nozzle 41 ends with a second axially parallel section 63 that is at the valve's longitudinal axis 10. Ideally the fuel inlet nozzle 41 should run flush and thus co-axial to the valve's longitudinal axis 10 in its section 63.
Manufacture of the fuel injection valve takes place in such a manner that function part 30 of the valve is manufactured first, which, inter alia, comprises of the actuator 1, 2, 5 and the sealing valve 15, 19. The valve sleeve 6 is, for example, intended to be the framework. An adjustment process is linked to this manufacturing process in which the already completed stroke adjustment of the valve part that can be moved in an axial direction (valve needle 14, valve closing body 19) as well as the dynamic and static flow quantities are carried out. The fuel inlet nozzle 41 is subsequently firmly fixed to the function part 30 in such a manner that the fuel inlet nozzle 41 ends at the valve's longitudinal axis 10. The fuel inlet nozzle 41 is, thereby, inserted with its end 47 of section 63 that is axially parallel into, for example, the opening 11 of valve sleeve 6 and subsequently affixed at the valve sleeve 6 of function part 30 by means of welding, particularly laser welding. Apart from welding, other join technology such as soldering, bonding or slots can be made use of.
In order to stabilise and protect the angled, metallic fuel inlet nozzle 41 that e.g. has a thin-walled pipe 44, the fuel inlet nozzle 41 together with, for example, the tubular framework 42 must subsequently be extrusion-coated with a synthetic material. Connecting plug 56 that is also sprayed on can, thereby, be part of the framework 42. Sufficient stability and good protection for the fuel inlet nozzle 41 will already have been provided if the framework 42 only to a large extent envelops section 63 of the fuel inlet nozzle 41, running parallel to the axis, while

the angled section 62 of the pipe 44 lies exposed in the required angle a and is thus not enveloped by the synthetic material.
The fuel inlet nozzle 41 should ideally be provided with a saw-toothed profile 61 at its upstream end in the region of the angled section 62 so that a simple connection to a fuel-supplying hose, which is not illustrated and which is pushed onto the saw-toothed profile, and to a hose clamp is enabled. Other sealing measures such as O Rings can be dispensed with in this manner.


Claims
1. Process for the manufacture of a fuel injection valve that has a valve
longitudinal axis (10), a fuel inlet nozzle (41), a valve closing body (19)
that can be moved in an axial direction along the valve's longitudinal
axis (10) and which works together with a valve seat (16) provided at a
valve seat body (15) and at least one spray opening (27) downstream
from the valve seat (16), characterised in that
- a function part (30) of the valve is manufactured that comprises of
- an actuator (1, 2, 5) and a closing body (15, 19),
- this function part (30) gets adjusted with regard to the stroke and
- flow quantities
- a fuel inlet nozzle (41) is made available separately that, beginning
- from an entry pot (60), runs at an angle (a) to the valve's
- longitudinal axis (10), this angle being greater than 0° and less
- than/equal to 90°, and
- the fuel inlet nozzle (41) is connected firmly to the function part (30)
- in such a manner that the fuel inlet nozzle (41) ends at the valve's
- longitudinal axis (10).

2. Process according to Claim 1, characterised in that the fuel inlet nozzle
3. (41) is affixed at a valve sleeve (6) of the function part (30).
4. Process according to Claim 2, characterised in that fixing of the fuel
5. inlet nozzle (41) takes place by means of welding, laser welding in
6. particular.

7. Process according to one of Claims 1 to 3, characterised in that the
8. fuel inlet nozzle (41) is at least partially enclosed by a synthetic
9. framework (42) after it's fastening.
10. Fuel injection valve for fuel injection systems of internal combustion
11. engines with a valve longitudinal axis (10), with a fuel inlet nozzle (41),
12. with a valve closing body (19) that can be moved in an axial direction
13. along the valve's longitudinal axis and that works together with a valve
14. seat (16) provided at a valve seat body (15) and with at least one spray
15. opening (27) downstream from the valve seat (16), characterised in
16. that the fuel inlet nozzle (41), beginning from an entry port (60), runs at
17. angle (a) to the valve's longitudinal axis (10), this angle being greater
18. than 0° and less than/equal to 90° and ending finally at the valve's
19. longitudinal axis (10).
20. Fuel injection valve according to Claim 5, characterised in that the
21. entry port (60) is mounted at a level that runs parallel to the valve's
22. longitudinal axis (10).
23. Fuel injection valve according to Claim 5 or 6, characterised in that the
24. fuel inlet nozzle (41) is designed with a thin-walled pipe (44) that is at
25. least partially embedded in a framework (42).
26. Fuel injection valve according to Claim 7, characterised in that the
27. framework (42) is made from a synthetic material.
28. Fuel injection valve according to Claim 7 or 8, characterised in that the
29. framework (42) only to a large extent, envelops section (63) of the fuel
30. inlet nozzle (41), running parallel to the axis.

10. Fuel injection valve according to one of Claims 5 to 9, characterised in that the fuel inlet nozzle (41) is provided with a saw-toothed profile (61) at its upstream end.
Dated this 23 day of June 2006


Documents:

2303-CHENP-2006 CORRESPONDENCE OTHERS 19-08-2011.pdf

2303-CHENP-2006 AMENDED CLAIMS 20-06-2012.pdf

2303-CHENP-2006 AMENDED PAEGS OF SPECIFICATION 20-06-2012.pdf

2303-CHENP-2006 EXAMINATION REPORT REPLY RECEIVED 20-06-2012.pdf

2303-CHENP-2006 FORM-3 20-06-2012.pdf

2303-CHENP-2006 OTHER PATENT DOCUMENT 20-06-2012.pdf

2303-CHENP-2006 POWER OF ATTORNEY 20-06-2012.pdf

2303-chenp-2006-abstract image.jpg

2303-chenp-2006-abstract.pdf

2303-chenp-2006-claims.pdf

2303-chenp-2006-correspondnece-others.pdf

2303-chenp-2006-description(complete).pdf

2303-chenp-2006-drawings.pdf

2303-chenp-2006-form 1.pdf

2303-chenp-2006-form 26.pdf

2303-chenp-2006-form 3.pdf

2303-chenp-2006-form 5.pdf

2303-chenp-2006-pct.pdf


Patent Number 253474
Indian Patent Application Number 2303/CHENP/2006
PG Journal Number 30/2012
Publication Date 27-Jul-2012
Grant Date 25-Jul-2012
Date of Filing 23-Jun-2006
Name of Patentee ROBERT BOSCH GMBH
Applicant Address Postfach 30 02 20, 70442 Stuttgart ,
Inventors:
# Inventor's Name Inventor's Address
1 REITER, Ferdinand Burgweg 1, 71706 Markgröningen
2 MAIER, Martin Meisenweg 12, 71696 Möglingen
PCT International Classification Number F02M61/16,51/06
PCT International Application Number PCT/EP2004/052904
PCT International Filing date 2004-11-10
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 103 60 774.9 2003-12-23 Germany