GB2416372A

GB2416372A - Fuel feed for an internal combustion engine with direct injection

Info

Publication number: GB2416372A
Application number: GB0510609A
Authority: GB
Inventors: Ingo Lausen; Cornelius Josephus Adri Deelen
Original assignee: Benteler Automobiltechnik GmbH
Current assignee: Benteler Automobiltechnik GmbH
Priority date: 2004-07-22
Filing date: 2005-05-24
Publication date: 2006-01-25
Anticipated expiration: 2025-05-24
Also published as: DE102004035648B4; GB2416372B; GB0510609D0; DE102004035648A1

Abstract

The fuel feed (1) for an internal combustion engine has a feed line (3) comprising a plurality of pipe sections (2). Between two pipe sections (2), a branch (4) designed for mounting on the engine housing is installed, in which connecting passages (5, 6) for transferring fuel from the feed line (3) to a fuel injection unit are provided. The tubular branch (4) has two connecting pieces (7, 7a) of a smaller diameter at its ends, which are tightly fitted into the ends (8) of the pipe sections (2). The end faces (9) of the pipe sections (2) contact annular end faces (10) of the middle section (11) of the branch (4), which is located between the connecting pieces (7, 7a). The middle section (11) supports a lateral connecting bracket (15), in which both the connecting passages (5, 6) and a mounting hole (16) for mounting the branch (4) on the engine housing are provided.

Description

24 1 6372 Fuel Feed for an Internal Combustion Ennine with Direct

Iniection The invention relates to a fuel feed for an internal combustion engine with direct injection.

A fuel feed of this type represents prior art owing to the disclosed content of DE 199 53 942 C2. It comprises a feed line consisting of a plurality of pipe sections. Adjacent end faces of adjoining pipe sections are arranged at a distance from one another. These areas are covered by branches which may be made of a light alloy such as aluminium or of plastic. The pipe sections are made of aluminium, steel or plastic.

At the end of each branch, diagonally opposite eye-like projections with parallel through holes are provided. By means of these projections, the branches can be secured to the engine housing. In addition to the two projections, a side arm featuring a blind hole is provided approximately half- way along the length of each branch. Via an inclined bore, this blind hole is connected to the area located within the branch between the two end faces of adjacent pipe sections. The feed line is connected to a fuel injection unit via the blind hole and the inclined bore.

The number of branches corresponds to the number of cylinders of the internal combustion engine. The free ends of the feed line may be sealed by caps, and these end caps may incorporate connections, for instance to a high-pressure fuel line or to a high-pressure sensor.

The known fuel feed is comparatively large in the area of the branches, because the ends of the pipe sections of the feed line are located within the branches. In addition, each branch has diagonally opposite mounting eyes at its ends, requiring an even larger installation volume.

On the basis of prior art, the invention is based on the problem of creating a fuel feed for an internal combustion engine with direct injection, which is constructed more compactly without reducing the proportion of fuel in the feed line.

This problem is solved by the features specified in claim 1.

According to this, the tubular branch has two connecting pieces of a smaller diameter at the ends. The connecting pieces are tightly fitted into the pipe sections. The end faces of the pipe sections lie against annular end faces of the middle section of the branch located between the connecting pieces In this way, the entire feed line, i.e. the pipe sections plus the branches installed between two pipe sections, is given an even external contour virtually free of any projections. The invention offers the further advantage that the transfer of high-pressure fuel to the fuel injection unit and the location of the branch on the engine housing are exclusively confined to the middle section of the branch. This further enhances the compact design of the unit.

The branch is preferably designed as a casting. The material is selected according to requirements. It may, for instance, be stainless steel.

To prevent the widening of the gap between the connecting pieces and the ends of the pipe sections by the pressure of the fuel, the wall thickness of the connecting pieces is less than the wall thickness of the ends of the pipe sections. It then appears to be expedient to join the overlapping areas of the connecting pieces to the ends of the pipe sections by brazing. However, other suitable joining methods ensuring a leak-proof branch area can be used The flow of fuel from one pipe section through the branch to the adjacent pipe section is improved by providing that the longitudinal passage in the branch extends towards the end faces of the connecting pieces in conically widening openings. As a result, the flow resistance due to the engagement between the connecting pieces of the branch and the ends of the pipe sections is not increased significantly The branch is made even more compact by the provision of a lateral connecting bracket in its middle section, in which both the connecting passages and a mounting hole for securing the branch to the housing are provided. The length of a connecting bracket of this type only insignificantly exceeds the distance between the end faces of the connecting pieces of the branch The connecting passages are represented by a blind hole in the connecting bracket and an inclined bore connecting the blind hole to the longitudinal passage in the central section. A transverse plane intersecting the axis of the blind hole extends immediately adjacent to the transverse plane intersecting the end face of the adjacent connecting piece. The inclined bore runs from the blind hole through an inclined transitional section between the branch and the connecting bracket. This, too, makes the branch even more compact. The axis of the inclined bore lies at an angle deviating from 90 both in relation to the axis of the blind hole and in relation to the axis of the longitudinal passage in the branch.

The compact design of the branch is promoted further by providing that the axes of the blind hole and of the mounting hole lie in a plane which is parallel to a plane extending through the axis of the longitudinal passage in the middle section.

To ensure that the inclined bore between the longitudinal passage in the branch and the blind hole in the connecting bracket can be produced faultlessly and without difficulty, the axis of the inclined bore intersects the opening of the connecting piece located diagonally opposite the blind hole.

In view of the fact that the inclined bore is expediently produced by drilling, the inclined bore terminates in a projection located in the longitudinal passage of the branch, the end face of which extends at right angles to the axis of the inclined bore. As a result, the use of a drill to produce the inclined bore does not involve any difficulties.

A further advantage is gained if the surface of the connecting bracket which lies opposite the openings of the blind hole and of the mounting hole lies approximately in a plane which also extends through the axis of the longitudinal passage in the branch.

To avoid unnecessary material accumulations, the mounting hole is continued in a sleeve-like extension of the connecting bracket.

An anti-rotation element is conveniently represented by a projection and is preferably cast integrally and acts together with a recess in a fuel injection unit (injector) to hold the injector in position. In SGDI (spray guided direct injection), the anti-rotation unit ensures that the spray pattern of the injector adopts a defined angle relative to the spark plug.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a horizontal axial section through a part of a fuel feed line to a fuel injection unit of an internal combustion engine with direct injection; Figure 2 shows a branch of the feed line from Figure 1; and Figure 3 is a front view of the illustration from Figure 1 in the direction of arrow lilt Reference number 1 in Figure 1 identifies a section of a fuel feed for an internal combustion engine with direct injection, which is not shown in detail.

The fuel feed 1 has a feed line 3 comprising a plurality of pipe sections 2 (Figures 1 to 3). Between two pipe sections 2 of this feed line 3, a branch 4 designed for mounting on the housing of the internal combustion engine is installed, in which connecting passages 5, 6 for transferring fuel from the feed line 3 to a fuel injection unit are provided. The number of branches 4 between two consecutive pipe sections 2 corresponds to the number of cylinders of the internal combustion engine.

The tubular branch 4 cast from stainless steel and then machined as required has two connecting pieces 7, 7a of a smaller diameter at its ends, which are tightly fitted into the ends 8 of the pipe sections 2 The end faces 9 of the pipe sections 2 contact annular end faces 10 of the middle section 11 of the branch 4 located between the connecting pieces 7, 7a. The wall thickness WD of the connecting pieces 7, 7a is less than the wall thickness WD1 of the ends 8 of the pipe sections 2.

The longitudinal passage 12 in the branch 4 terminates at the end faces 14 of the connecting pieces 7, 7a via conically widening openings 13.

If viewing Figures 1 to 3 together, it can further be seen that a lateral connecting bracket 15 is provided in the middle section 11 of the branch 4. In this connecting bracket 15, both the connecting passages 5, 6 and a mounting hole 16 are provided. The mounting hole 16 is used to secure the branch 4 to the engine housing.

The connecting passages 5, 6 are represented by a blind hole 5 in the connecting bracket 15 and an inclined bore 6 connecting the blind hole 5 to the longitudinal passage 12 in the branch 4. The axes 17, 18 of the blind hole and the mounting hole 16 lie in a common plane E - E which lies parallel to a plane E1 - E1 extending through the axis 19 of the longitudinal passage 12.

Figures 1 and 2 indicate that the axis 20 of the inclined bore 6 intersects the opening 13 of the second connecting piece 7a located diagonally opposite the blind hole 5. The inclined bore 6 terminates in a projection 21 extending into the longitudinal passage 12 of the branch 4, the end face 22 of which, which lies in the middle section 11, extends at right angles to the axis 20 of the inclined bore 6. The end face 22 faces the second connecting piece 7a.

Figure 3 shows that the surface 25 of the connecting bracket 15, which lies opposite the openings 23, 24 of the blind hole 5 and the mounting hole 16 respectively, extends approximately in a plane E2 - E2, which also extends through the axis 19 of the longitudinal passage 12 in the branch 4.

The mounting hole 16 is continued in a sleeve-like extension 26 of the connecting bracket 15 (Figure 3).

In the area between the blind hole 5 and the mounting hole 16, the connecting bracket 15 is provided with an anti-rotation element 27 in the form of an integrally cast projection. The anti-rotation element 27 acts together with a recess in a fuel injection unit (injector) to hold the injector in its position. As a result, it can be ensured - in particular in SGDI (spray guided direct injection) - that the spray pattern of the injector always adopts a defined angle relative to a spark plug.

Reference Numbers 1 - Fuel feed 2 - Pipe sections 3 - Feed line 4 - Branch - Blind hole 6 - Inclined bore 7 - First connecting piece to 4 7a - Second connecting piece to 4 8 - Ends of 2 9 - End faces of 2 - End faces to 11 11 - Middle section of 4 12 - Longitudinal passage in 4 13 - Openings of 7 14 - End faces of 7 - Connecting bracket 16 - Mounting hole 17 - Axis of 5 17 - Axis of 16 19 -Axis of 12 - Axis of 6 21 - Projection in 12 22 - End face of 21 23 - Opening of 5 24 - Opening of 16 - Surface of 15 26 Sleeve-like extension of 15 27 - Anti-rotation element WD - Wall thickness of 7, 7a WD1 - Wall thickness of 8 E-E - Plane through 17, 18 E1-E1 Plane through 19 E2-E2- Plane through 19 and 25

Claims

Claims: 1. A fuel feed for an internal combustion engine with direct

injection, the feed comprising a plurality of pipe sections and at least one branch for mounting on an engine housing between two pipe sections, wherein the tubular branch has first and second connecting pieces which fit inside the ends of the pipe sections and a middle section which fits between the ends of the pipe sections.
2. A fuel feed according to Claim 1, wherein the pipe sections have end faces which contact annular end faces of the middle section of the branch.
3 A fuel feed according to Claim 1 or 2, wherein the branch has connecting passages for transferring fuel from the feed to a fuel injection unit.
4. A fuel feed according to any preceding claim, wherein the connecting pieces have a diameter which is smaller at the ends than an internal diameter of the ends of the pipe sections.
5. A fuel feed according to any preceding claim, wherein the connecting pieces fit tightly inside the respective ends of the pipe sections.
6. A fuel feed according to any preceding claim, wherein the wall thickness (WD) of the connecting pieces is less than the wall thickness (Wry) of the ends of the pipe sections.
7 A fuel feed according to any preceding claim, wherein the branch presents a longitudinal passage with conically widening openings to the respective pipe sections.
8. A fuel feed according to any preceding claim, wherein a lateral connecting bracket is provided in the middle section of the branch, in which bracket both the connecting passages and a mounting hole are formed.
9. A fuel feed according to claim 8, wherein the connecting passages comprise a blind hole in the connecting bracket and an inclined bore connecting the blind hole to a longitudinal passage in the branch.
10. A fuel feed according to claim 9, wherein the axes of the blind hole and the mounting hole lie in a common plane (E - E) which lies parallel to a plane (E, - E,) extending through the axis of the longitudinal passage in the branch.
11. A fuel feed according to claim 9 or 10, wherein the axis (20) of the inclined bore points towards and passes through the opening of one of the connecting pieces.
12. A fuel feed according to any one of claims 9 to 11, wherein the inclined bore terminates in a projection from the middle section extending at right angles to the axis of the inclined bore.
13. A fuel feed according to any of claims 9 to 12, wherein the surface of the connecting bracket which lies opposite the openings of the blind hole and the mounting hole lies approximately in a plane (E2- E2) which also extends through the axis of the longitudinal passage in the branch.
14. A fuel feed substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

14. A fuel feed according to Claim 8, wherein the mounting hole is continued in a sleeve-like extension of the connecting bracket.

15. A fuel feed according to any preceding claim, wherein an antirotation element (27) is provided on the branch (4).

16. A fuel feed substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

17 Any novel feature or combination of features disclosed herein. f

Amendments to the claims have been filed as follows 1. A fuel feed for an internal combustion engine with direct injection, the feed comprising a plurality of pipe sections and at least one branch fo' mounting on an engine housing between two pipe sections, wherein the tubular branch has first and second connecting pieces which fit inside the ends of the pipe sections, a middle section which fits between the ends of the pipe sections, and connecting passages for transferring fuel from the feed to a fuel injection unit, wherein a lateral connecting bracket is provided in the middle section of the branch, in which bracket both the connecting passages and a mounting hole are formed.

2. A fuel feed according to Claim 1, wherein the pipe sections have end faces which contact annular end faces of the middle section of the branch. ( r 1

t'' 3. A fuel feed according to any preceding claim, wherein the connecting pieces have a diameter which is smaller at the ends than an internal diameter e c; of the ends of the pipe sections. (

A, 4. A fuel feed according to any preceding claim, wherein the connecting pieces fit tightly inside the respective ends of the pipe sections. ( (

5. A fuel feed according to any preceding claim, wherein the wall thickness (WD) of the connecting pieces is less than the wall thickness (WD,) of the ends of the pipe sections.

6. A fue! feed accordl,,g to any preceding claim, wheioirn the branch presents a longitudinal passage with conically widening openings to the respective pipe sections. f 1)

7. A fuel feed according to any preceding claim, wherein the connecting passages comprise a blind hole in the connecting bracket and an inclined bore connecting the blind hole to a longitudinal passage in the branch.

8. A fuel feed according to claim 7, wherein the axes of the- blind hole and the mounting hole lie in a common plane (E- E) which lies parallel to a plane (E1- E1) extending through the axis of the longitudinal passage in the branch.

9. A fuel feed according to claim 7 or 8, wherein the axis of the inclined bore points towards and passes through the opening of one of the connecting pieces.

10. A fuel feed according to any one of claims 7 to 9, wherein the inclined bore terminates in a projection from the middle section extending at right 4. '' angles to the axis of the inclined bore. (. ( t ( re

11. A fuel feed according to any one of claims 7 to 10, wherein the surface . . of the connecting bracket which lies opposite the openings of the blind hole ( . . . . and the mounting hole lies approximately in a plane (E2 - E2) which also extends through the axis of the longitudinal passage in the branch. / (

12. A fuel feed according to any preceding claim, wherein the mounting hole is continued in a sleeve-like extension of the connecting bracket.

13. A fuel feed according to any preceding claim, wherein an antirotation element is provided on the branch.