Fuel distribution rail

Abstract

A fuel distribution rail for a fuel injection system of an internal combustion engine has connected base tube sections defining a longitudinal fuel channel with connector devices fixed on the base tube and a force relieving groove provided on the outer surface of the base tube sections spaced from the connector devices which extend over at least a part, preferably at least over a greater part of the outer surface of the base tube. In one form a cylindrical base tube has a circular force relieving groove surrounding the base tube spaced from the connector device.

Claims

1. A fuel distribution rail for a fuel injection system for an internal combustion engine, having a base tube comprising at least one tube section defining a fuel channel extending in a longitudinal direction of the base tube, at least one connector device fixed on the base tube, at least one force relieving groove on the outer surface of the base tube spaced from the at least one connector device and extending over at least part of the outer surface of the base tube, wherein the base tube comprises a metal tube.

2. A fuel distribution rail in accordance with claim 1, wherein said base tube comprising a plurality of tube sections with several connector devices distributed over a length of the base tube and a force relieving groove on the surface of said tube sections spaced from each connector device.

3. A fuel distribution rail in accordance with claim 2, wherein said at least one connector devices are connector adapters for connecting together said plurality of tube sections of the base tube.

4. A fuel distribution rail for a fuel injection system for an internal combustion engine, having a base tube comprising at least one tube section defining a fuel channel extending in a longitudinal direction of the base tube, at least one connector device fixed on the base tube, at least one force relieving groove on the outer surface of the base tube spaced from the at least one connector device and extending over at least part of the outer surface of the base tube, wherein said base tube comprising a plurality of tube sections with several connector devices distributed over the length of the base tube and a force relieving groove on the surface of said tube sections spaced from each connector device, wherein said at least one connector devices are connector adapters for connecting together said plurality of tube sections of the base tube, wherein said connector adapters include flange components each defining a recess and said base tube includes metal tube sections, preferably of steel or essentially of metal, particularly essentially of steel with the ends of said tube sections in said recesses.

5. A fuel distribution rail in accordance with claim 3, wherein said connector adapters have a flange component defining recesses connected to said tube section at least partially surrounding an end of said tube sections.

6. A fuel distribution rail in accordance with claim 5, wherein the connection of said connector adapter and said base tube or tube sections is a soldered connection and/or a welded connection.

7. A fuel distribution rail in accordance with claim 6, wherein the flange component of the connector adapters is connected to the base tube or a tube section over a soldered connection and/or a welded connection completely surrounding said ends of said tube sections.

8. A fuel distribution rail in accordance with claim 1, wherein at least one connector device is a connecting branch connected to the base tube or a tube section, the connection branch extending transversely to the base tube or transversely to the tube section and the connection branch has a fluid connection with the fuel channel.

9. A fuel distribution rail in accordance with claim 1, wherein said force relieving groove surrounds an entire outer circumference of the base tube or the tube section.

10. A fuel distribution rail in accordance with claim 1, where said force relieving groove has a crescent shaped that includes a circular crescent shaped cross section.

11. A fuel distribution rail in accordance with Claim 1, wherein said force relieving groove has a maximum depth (t) of 0.2 to 1 mm relative to the outer surface of said base tube.

12. A fuel distribution rail in accordance with claim 1, wherein a distance (A) between a force relieving groove minimum depth of the force relieving groove of the tube section and the tube end of the tube section incorporated in the next neighboring connector adapter is 7 to 15 mm.

13. A fuel distribution rail in accordance with claim 1, wherein a distance between a groove minimum depth of the force relieving groove and a central axis or longitudinal central axis (L) of a next neighboring connection adapter is 8 to 20 mm.

14. A fuel distribution rail in accordance with claim 1, wherein an outer diameter of the base tube or of the tube section is 15 to 27 mm.

15. A fuel distribution rail in accordance with claim 1, wherein a wall thickness (d) of the base tube or the tube section is 2 to 4 mm.

16. A fuel distribution rail in accordance with claim 4, wherein at least one connector device is a connecting branch connected to the base tube or a tube section, the connection branch extending transversely to the base tube or transversely to the tube section and the connection branch has a fluid connection with the fuel channel.

17. A fuel distribution rail in accordance with claim 4, wherein said force relieving groove surrounds an entire outer circumference of the base tube or the tube section.

18. A fuel distribution rail in accordance with claim 4, where said force relieving groove has a crescent shaped that includes a circular crescent shaped cross section.

19. A fuel distribution rail in accordance with claim 4, wherein said force relieving groove has a maximum depth (t) of 0.2 to 1 mm relative to the outer surface of said base tube.

20. A fuel distribution rail in accordance with claim 4, wherein a distance (A) between a force relieving groove minimum depth of the force relieving groove of the tube section and the tube end of the tube section incorporated in the next neighboring connector adapter is 7 to 15 mm.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 a side view of a fuel distribution rail according to the present invention.

(2) FIG. 2 an enlarged sectional view of the portion of the fuel distribution rail of FIG. 1, within the encircled portion of FIG. 1 designated C.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

(3) FIG. 1 shows a fuel distribution rail in accordance with the present invention for a fuel injection system for a combustion engine. The fuel distribution rail has a base tube or housing 1 defining a fuel channel 2 extending longitudinally of the base tube 1. The base tube 1 with its fuel channel 2 is preferably in the form of a steel tube. A number of connector devices 4 are preferably, and in the example, arranged along the length of the base tube 1.

(4) In the preferred embodiment and in the example, the base tube 1 is divided into a number of tube sections 11 which are preferably made of steel. A part of the connector devices 4 are fashioned as connector adapters 5, each of which connect two tube sections 11 of the base tube 1 with one another.

(5) It is within the framework of this invention that each connector adapter 5 is made of steel or essentially of steel. Preferably and in the example, every connector adapter 5 has two surrounding flange components 6 and a connection piece 12 extending transversely to the base tube 1 or to the fuel channel 2. In the example, a fixing screw 13 is passed through the connection pieces 12. The fuel distribution rail is fastened with the fixing screws 13 to an engine (not shown in the figures).

(6) In the recommended embodiment and in the example, a connector adapter 5 is connected to the attached tube sections 11 by soldered joints. As shown above, such a connection area is particularly mechanically unstable and therefore is a weak point of the fuel distribution rail with regard to mechanical stresses. Preferably and in the example, the flange component 6 of each connector adapter 5 forms a recess or bore 14 that receives an end of a tube section 11 where the tube section end and the flange component are joined by a soldered joint 8. Preferably, and in the example, the end of the tube sections 11 grip the flange components 6 within recesses 14 with a tight fit and the surrounding tube sections are connected to the flange components 6 in these connecting recesses 14 by soldered joints 8.

(7) It is within the framework of this invention that at least one force relieving groove 9 is provided in the region of the connector adapter 5 in the outer surface of the base tube 1 or the outer surface of each tube section 11. As per the preferred embodiment and in the example, a force relieving groove 9 extends around the entire circumference of the base tube 1 or the tube section 11. As recommended and in the example, there is such a force relieving groove 9 in each of the tube sections 11 on both sides of a connector adapter 5.

(8) It is further within the framework of this invention that, as in the example, other connector devices 4 in the form of connecting branches 7 are connected to the base tube 1 or to the tube sections 11 of base tube 1. The connecting branches 7 extend transversely to the base tube 1 or transversely to the fuel channel 2 and are in fluid communication with the fuel channel 2 through connection bores 15 provided in the base tube 1 or in the tube sections 11. The connecting branches 7 are preferably and in the example, arranged parallel to each other. It is within the framework of this invention that there is also a force relieving groove 19 or force relieving grooves on the connecting branches 7 or on the base tube sections 11 on both sides opposite to connecting branches 7, (See FIG. 1).

(9) In accordance with the invention, the distance a between the minimum depth of a force relieving groove 9 and the longitudinal central axis L of the adjacent connection piece 12 is expediently and in the example, 8 to 20 mm. The distance A between the groove minimum depth 10 of a force relieving groove 9 of a tube section 11 and the tube end 16 of the associated tube section 11 enclosed in the next neighboring connector adapter 5 is preferably, and in the example, 10 to 12 mm.

(10) The groove minimum depth 10 is the lowest point of the force relieving groove 9 relative to the outer surface of the base tube 1. Particularly it can be seen in FIG. 2 that a force relieving groove 9 has preferably a circular crescent shaped cross section. Preferably a force relieving groove 9 has a maximum depth t of 0.4 to 0.6 mm. The maximum depth t is measured from the groove minimum depth 10 to the outer surface of the base tube section 11. The maximum width b of a force relieving groove 9 relative to the outer surface of the tube section 11 is, as per recommendation, 2 to 3 mm.

(11) In this illustrated embodiment the dimensions of the force relieving groove as described herein is contemplated for a base tube 1 or tube sections 11 having a diameter expediently 15 to 27 mm, and preferably 17 to 25 mm. The wall thickness of the base tube 1 or base tube sections 11 is expediently 2 to 4 mm and preferably 2 to 3.5 mm. It should be noted that in the embodiment illustrated, the base tube 1 is comprised of cylindrical tube sections 11. Hence, the force relieving grooves 9 are illustrated as circular, surrounding the outer cylindrical surface of the base tube 1, or its tube sections 11. It must be understood, however, that the base tube 1 may not be cylindrical and could have a square, rectangular, oval, or other suitable cross-section. In such instances the force relieving grooves would have a corresponding peripheral configuration.

(12) Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.