Title of Invention


Abstract A fuel injection system for internal combustion engines, with a high-pressure fuel accumulator (1) supplied by a high-pressure fuel pump, is proposed. The high-pressure fuel accumulator (1) has the form of a hollow sphere (2) which is welded together from two forged hollow hemispheres (3) and (4). Fastening elements (6, 7, 8, 9) formed on during the forging operation serve for fastening the high-pressure fuel accumulator (1) in a vehicle.
Full Text

ROBERT BOSCH GMBH,70442 Stuttgart
Fuel inj action' system—--..
Prior art
The invention proceeds from a fuel injection system according to the pre-characterizing clause of the main claim. In such a fuel injection system, known, for example, from EP 0,507,191, the high-pressure fuel accumulator consists of a prefabricated pipe, onto which connecting sockets are pushed for the purpose of connecting t^ie fyel injection valves or the high-pressure 3,ins coming fw$m th# high-pressure fuel pump. Suoh a high-pressure fuel accumulator is relatively bulky and therefore requires a large amount of installation space* Moreover # it is relatively heavy, and it has an unfavourable hydraulic behaviour.
AdvantageH-~o£-~fche- invention-'
The fuel injection system according to the invention, having the features of the characterizing clause of the patent claim, now provides a high-pressure fuel accumulator which requires a smaller amount of installation space and has less weight and the hydraulic behaviour of which is extremely favourable.
An exemplary embodiment of the invention is illustrated in the drawing and is explained in more detail in the description. In the drawing, Figure 1 shows a section through the spherical high-pressure fuel accumulator with the fastening elements. Figure 2 shows a detail of a connection and Figure 3 shows a section in

a plane different from that of Figure 1. Description of the exemplary embodiment
A high-pressure fuel accumulator 1 has the form of a hollow sphere 2 which is composed of two hollow hemispheres 3 and 4. The two hemispheres 3 and 4 are produced in a forging operation and are subsequently welded together at their annular contact faces. A weld seam bears the reference numeral 5. However, the two hollow hemispheres 3 and 4 may also be screwed together in a way which is not illustrated.
The two hollow hemispheres 3 and 4 have lug-like fastening elements 6, 7, 8 and 9 which are formed on during forging and correspond to one another and which are each provided, preferably after being welded together, with a passage bore 10 or 11 for fastening screws (not shown), by means of which the high-pressure fuel accumulator 1 can be fastened in a vehicle.
As may be seen in the section diagram according to Figure 1, connecting bores 12, 13, 14 and 15 are provided in a plane 4 lying perpendicularly to the weld seam 5, the said connecting bores being intended for the connection of lines which serve for connecting the high-pressure fuel accumulator 1 to electrically controlled injection valves. Neither the lines nor the injection valves are illustrated. The four connecting bores 12 to 15 are located diametrically opposite one another in pairs and each have an internal thread 16 and a passage bore 18 of smaller diameter, which inwardly adjoins the internal thread 16 via a hollow-conical sealing face 17 and which is connected to an inner accumulator chamber 19. These facts are illustrated on an enlarged scale in Figure 2. The inner accumulator chamber 19 has, for example, a volume of about 33 cm3.
Figure 3 illustrates a section through the sphere 2 which is in a plane different from that of the section according to Figure 1. It shows a connecting bore 20, to which a delivery inflow from a high-pressure fuel feed

pump can be connected. Provided opposite the connecting bore 20 is a further connecting bore 21, into which a pressure sensor or a control valve can be screwed.
The two connecting bores 20 and 21 are also provided with an internal thread 16, with a sealing face 17 and with a passage bore 18. High-pressure lines can be inserted sealingly and fixedly into all the connecting bores 12 to 15 and 20 and 21 in a way which is not illustrated, and these high-pressure lines are then connected to the inner accumulator chamber 19 via the passage bgres 18.

ROBERT BOSCH GMBH, 70442 Stuttgart Claims
1. Fuel injection system for internal combustion engines, with a high-pressure fuel pump which supplies fuel to a high-pressure fuel accumulator (1) , out of which the fuel is fed to electrically controlled injection valves in order to be injected into the combustion spaces of an auto-ignition internal combustion engine, the high-pressure fuel accumulator (1) being provided with connecting bores (12, 13, 14, 15) for the fuel feed and fuel discharge and with fastening elements (6, 7, 8, 9) , characterized in that the high-pressure fuel accumulator (J) has the form of a hollow sphere (2).
2. Fuel injection system according to Claim 1, characterized in that the hollow-spherical high-pressure fuel accumulator (1) is produced from two forged hollow hemispheres (3 and 4).
3. Fuel injection system according to Claim 2, characterized in that the two hollow hemispheres (3 and 4) are assembled at their annular contact faces by means of a weld seam (5).
4. Fuel injection system for internal combustion engines, substantially as herein described with reference to the accompanying drawings.



mas-1997-1634-claims duplicate.pdf

mas-1997-1634-claims original.pdf

mas-1997-1634-correspondance others .pdf

mas-1997-1634-correspondance po.pdf

mas-1997-1634-description complete duplicate.pdf

mas-1997-1634-description complete original.pdf


mas-1997-1634-form 1.pdf

mas-1997-1634-form 26.pdf

mas-1997-1634-form 3.pdf

mas-1997-1634-form 4.pdf

Patent Number 204458
Indian Patent Application Number 1634/MAS/1997
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 22-Feb-2007
Date of Filing 22-Jul-1997
Name of Patentee ROBERT BOSCH GMBH,
Applicant Address postfach 30 02 20 70442 Stuttgart,
# Inventor's Name Inventor's Address
PCT International Classification Number F02M37/04
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 196 47 049.8 1996-11-14 Germany