Common rail distributor rail

Abstract

A common rail distributor rail (2) for supplying an internal combustion engine with fuel comprises an inner pressure pipe (3), an outer jacket (4) as well as joint pieces (5) for connecting high-pressure conduits. Thereby, the joint pieces (5) are fixedly connected to the outer jacket (4), in particular by way of thermal joining, and by way of this form a double-walled system with a pressure-tight sealing of the jacket.

Claims

1. A common rail distributor rail (2) for supplying an internal combustion engine with fuel, comprising an inner pressure pipe (3), an outer jacket as well as joint pieces (5) for connecting high-pressure conduits, characterised in that the joint pieces (5) are fixedly connected to the outer jacket, in particular by way of thermal joining, and form a sealing of the jacket by way of this.

2. A distributor rail (2) according to claim 1, wherein the joint pieces (5) each comprise circumferential joining locations (41) to the jacket.

3. A distributor rail (2) according to claim 1, wherein the jacket is formed by a continuous jacket pipe (4).

4. A distributor rail according to claim 1, wherein the jacket is formed by a row of individual pipe pieces which are connected to one another by the joint pieces (5).

5. A distributor rail (2) according to claim 1, wherein pressure pipe connections (31) are formed on the pressure pipe (3) and are provided for connection to a high-pressure conduit by way of a biting edge sealing, in particular by way of a pressure pipe connection (31) comprising a plane surface, against which a biting edge of a conduit connection (61) of a high-pressure conduit can be pressed.

6. A distributor rail (2) according to claim 1, wherein the joint pieces (5) are manufactured by way of cutting out from a flat material or by way of cutting off from a profile rod.

7. A distributor rail (2) according to claim 6, wherein the joint pieces (5) comprise elements (53) for fastening the joint pieces (5) and thus the distributor rail (2) to a motor.

8. A distributor rail (2) according to claim 6, wherein at least one of the joint pieces (5) is manufactured from a flat material with a different thickness than the other joint pieces (5), in particular with at least double the thickness than the other joint pieces (5)

9. A distributor rail (2) according to claim 6, wherein at least one of the joint pieces (5) is manufactured by way of cutting off a piece with a first length from the profile rod, and this first length is a different length than the other joint pieces, in particular at least twice the length of other joint pieces (5).

10. A distributor rail (2) according to claim 1, wherein at least one section, in particular an end of the pressure pipe (3) and one of the joint pieces (5) are positively and/or non-positively connected to one another and this positive connection forms a rotation lock of the pressure pipe (3) with respect to this joint piece (5).

11. A distributor rail (2) according to claim 10, wherein a fixation element (92) is present, said fixation element eliminating a play of the rotation lock.

12. A distributor rail (2) according to claim 1, wherein a further fixation element is present, said further fixation element fixing a mutual position between at least one joint piece (5) and the pressure pipe (3) in the axial direction, and wherein in particular the further fixation element is identical to a fixation element (92) which eliminates a play of the rotation lock.

13. A distributor rail (2) according to claim 1, comprising a continuous leakage pipe (8) for leading away back-flowing fuel, said leakage pipe running parallel to the pressure pipe (3) and being fastened to the joint pieces (5).

14. A distributor rail (2) according to claim 13, wherein the leakage pipe (8) is fastened with hollow connecting elements (81) to the joint pieces (5), wherein these connecting elements (81) are each envisaged to lead back-flowing fuel into the leakage pipe (8).

15. A distributor rail (2) according to claim 13, wherein the leakage pipe (8) is a profile pipe, in cross section comprises at least one flat wall section and is assembled with this flat wall section against the joint piece (5), in particular wherein the leakage pipe (8) is a square pipe.

Description

[0068] The subject-matter hereinafter described in more detail by way of preferred embodiment examples which are represented in the accompanying drawings. In each case are schematically shown in:

[0069] FIG. 1 a view of a distributor rail;

[0070] FIG. 2 a longitudinal section through an end of the distributor rail with a pressure pipe and jacket pipe;

[0071] FIG. 3 a plan view of the end of the distributor rail;

[0072] FIG. 4 a longitudinal section through one end of a distributor rail with a pressure pipe and jacket pipe and further elements;

[0073] FIG. 5 a cross section through a distributor rail in the region of a joint piece, with a conical connection;

[0074] FIG. 6 a cross section through a joint piece in the region of a rotation lock; and

[0075] FIG. 7 a cross section through a distributor rail in the region of a joint piece, with a connection with a biting edge.

[0076] Basically, in the figures the same parts are provided with the same reference numerals

[0077] FIG. 1 shows a view of a distributor rail 2. What is visible is a jacket pipe 4 with joint pieces which are rowed thereon. The joint pieces 5 are each welded with round weld seams 41 to the jacket pipe 4 in a manner following the circumference of the jacket pipe 4. The jacket pipe 4 can be of one part over the complete length of the distributor rail 2, or however be designed as a multi-part jacket, wherein individual part-sections of the jacket each reach from one joint piece 5 to the adjacent joint piece 5 or also up to a more remote joint piece 5. Here, the joint pieces 5 serve for connecting pressure conduits as well as for fastening the distributor rail 2 to the engine (not shown).

[0078] FIG. 2 shows a longitudinal section through sections of the distributor rail 2 and FIG. 3 a plan view of these. A pressure pipe which runs in the jacket pipe 4 is not shown for reasons of clarity. Apart from the already described elements, pressure pipe connections 31, at which departing high-pressure conduits (injector conduits) are connectable to the pressure pipe 3 are yet visible.

[0079] A rotation lock 55 is arranged in the region of a double joint piece 5 which is arranged to the left in the picture. Here, the rotation lock 55 is designed as a flattened part of the circular circumference of the opening for the pressure pipe. FIG. 6 shows the rotation lock 55 in view (in the axial direction) of the double joint piece 5 on its own. The rotation lock 55 with a correspondingly shaped flattened region of the pressure pipe 3 forms a positive connection and fixes a rotation position of the pressure pipe 3 with respect to the double joint piece 5.

[0080] FIG. 4 shows a further longitudinal section through an end of a distributor rail 2 with a pressure pipe 3 and a jacket pipe 4 and further elements which are connected onto the distributor rail 2. Double-walled injector conduits or high-pressure conduits or other components such as e.g. flow limiters or pressure sensors etc. can be connected to each of the joint pieces 5 via intermediate pieces 7 (FIG. 7). Inner pressure-conduits of the high-pressure conduits are connected onto the pressure-pipe 3 in a pressure-tight manner by way of cone connections. A feed conduit is likewise connectable onto the pressure-pipe 3 via a cone connection. The high-pressure conduits and feed conduits are not considered as part of the distributor rail 2.

[0081] The pressure pipe 3 comprises an upper flattened region with a pressure pipe connection 31, and a lower flattened region 35 which interacts with the flattened region of the rotation lock 55 on the joint piece and thus realises the rotation lock.

[0082] The jacket pipe 4 here, up to the very left, is represented in a continuous manner. If, as is shown in FIG. 2, the double joint piece 5 also comprises the rotation lock 55 which indeed is formed on a narrowing which reaches inwards up to the pressure-pipe 3, then the continuous jacket pipe 4 would reach from the right only up to this narrowing. The short section of the jacket which remains to the left of the narrowing is then formed by a separate pipe piece which is typically likewise welded to the double joint piece 5.

[0083] FIG. 5 shows a cross section through a distributor rail 2 in the region of a joint piece 5. Visible here, apart from the already described elements, are: [0084] A pipe region 51, at which the joint piece 5 is in connection with the jacket pipe 4. A cross section of the jacket pipe 4 is visible in this, with inwardly directed webs 33 for spacing the pressure pipe 3, and with corresponding grooves 34 for forming an intermediate space. [0085] A connection region 52, at which a high-pressure conduit can be connected onto the joint piece 5 via an intermediate piece 7. Here, a conduit connection 61 of the high-pressure conduit can be pressed with an outer cone against a pressure pipe connection 31 of the pressure pipe 3 with an inner cone 32. On the one hand, the intermediate piece 7 presses the conduit connection 61 against the pressure pipe connection 31, and on the other hand forms a transition intermediate space between the intermediate space of the pressure pipe 3 and jacket pipe 4 and an intermediate space of the inner pipe and outer pipe of the high-pressure conduit. [0086] A fastening region 53 for fastening the joint piece 5 to an engine or to another carrier object. [0087] A leakage pipe carrier 54 for fastening a leakage pipe 8. This leakage pipe can receive fuel which is from the injection valves and which flows back via (non-drawn) return conduits, and leads it further back to the fuel source. The leakage pipe 8 is assembled on the leakage pipe carrier 54 by way of a hollow screw 81, optionally with sealing elements between the hollow screw 81 and the leakage pipe carrier 54, in the case that the sealing effect of the screw thread is insufficient. The leakage pipe carrier 54 can be shaped out as one piece on the joint piece 5. Fuel flows through the return conduit into the hollow screw 81 and through a bore on the circumference of the hollow screw 81 into the leakage pipe 8.

[0088] A closure element 93, here in the form of a screw, can be opened in the case of a service, and thereby be used for restricting the location of a leakage.

[0089] FIG. 7 shows a cross section through a distributor rail 2 in the region of a joint piece 5, similarly to FIG. 5. Apart from the already described elements, here a connection with a biting edge is represented instead of a cone connection: a conduit connection 61 of the high-pressure conduit is designed as a biting edge and is pressed against a plane surface on the connection region 31 of the pressure pipe 3 by way of the intermediate piece 7 which for example is screwed to the joint piece.