Fuel rail clamping arrangement

Abstract

A fuel rail arrangement for an engine includes a fuel rail mounting cradle and a fuel rail fixed to the cradle. The fuel rail includes one or more outlets connected to respective fuel injector pipes. The fuel rail arrangement includes a clamp to fix both the rail to the cradle and to fix the fuel injector pipes to respective outlets in the fuel rail.

Claims

1. A fuel rail arrangement for an engine, the fuel rail arrangement comprising: a fuel rail mounting cradle including a first fuel rail mounting cradle recess and a second fuel rail mounting cradle recess; a fuel rail received within said first fuel rail mounting cradle recess and fixed to said fuel rail mounting cradle, said fuel rail including one or more outlets connected to respective fuel injector pipes; common fixing means to fix both said fuel rail to said fuel rail mounting cradle and fix said fuel injector pipes to respective said outlets in said fuel rail, said common fixing means includes clamping means adapted to provide a force to hold said fuel injector pipes into position to respective said fuel outlets on said fuel rail, said force additionally providing force to secure said fuel rail to said fuel rail mounting cradle, said second fuel rail mounting cradle recess receiving a camshaft of said engine therein such that said second fuel rail mounting cradle recess partially surrounds said camshaft.

2. A fuel rail arrangement as claimed in claim 1 wherein said clamping means includes bracket means which includes a bracket means recess within which said camshaft is located, and wherein said fuel rail mounting cradle and said bracket means are formed as separate components such that said second fuel rail mounting cradle recess co-operates with said bracket means recess surround and retain the camshaft.

3. A fuel rail arrangement as claimed in claim 2 wherein said bracket means includes at least one tapping or bore to allow a securing means to pass therethrough to a tapping or bore in said fuel rail mounting cradle.

4. A fuel rail arrangement as claimed in claim 2 wherein said bracket means includes at least one pipe tapping or bore to allow said fuel injector pipes to be connect and/or tightened to respective said outlets in said fuel rail.

5. A fuel rail arrangement as claimed in claim 4 including a screw adapted to cooperate with said pipe tapping or said bore to tighten to said outlets in said fuel rail.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIGS. 1a and 1b shows a simple example according to one aspect; FIG. 1a shows a schematic isometric view and FIG. 1b shows a cross sectional view;

(2) FIGS. 2a, b, c and d show further examples according to further aspects;

(3) FIGS. 3a and b shows yet further alternative examples;

(4) FIG. 4 shows how the designs of the FIG. 2 can be implemented and the figure shows an example of the complete rail is located, e.g. onto a cylinder engine block;

(5) FIGS. 5a and b shows an alternative example and how the rail may be clamped into a bracket/cradle by the high pressure pipe load; and

(6) FIGS. 6a and 6b show how the design of FIG. 5 may be such that the upper and lower portions of the cradle bracket are formed such that surround the camshaft (rocker shaft).

DETAILED DESCRIPTION OF THE INVENTION

(7) FIGS. 1a and b shows a simple example according to one aspect; FIG. 1a shows a schematic isometric view and FIG. 1b shows a cross sectional view. The figure shows a cradle or bracket 1 which is adapted to receive/locate a fuel rail 2. It is to be noted that in the figures, only a portion of the fuel rail is shown. The cradle can be located on the cylinder head forging and may in preferred examples be incorporated into the cylinder head forging. In examples the fuel rail may have flat surfaces (e.g. via machining) in the region where they are fitted to the cradle so as to cooperate with appropriate flat surfaces of the cradle to ensure better fitting.

(8) A mounting block/plate 3 is used to secure the common rail into the cradle/bracket means, and is fitted to the cradle by any suitable means such as by screw or bolts means 4, into respective thread in the bracket/cradle. The common rail includes a number of outlets 7 to high pressure (HP) pipes 5 which feed fuel to corresponding injectors. In examples the pipe, is connected to the fuel outlet from the common rail using the same mounting block/plate 3.

(9) The mounting block/plate may include a bore through which the pipe is fitted to corresponding fuel outlet port in the common rail, e.g. via screw means 6 may be used to tighten the respective end of the pipe to the fuel outlet.

(10) There may be one or more brackets/cradles; the number and location may vary according to design. Thus in this example, the means for fixing the common rail to the engine (e.g. cylinder head) utilizes a fitting (bracket) which is also used to secure/fix the fuel pipe to the fuel outlet of the common rail. By having this common component the high pressure pump pipe mounting/tightening features are integrated into the (rail clamp) clamping means.

(11) FIGS. 2a, b, c and d show alternative designs. FIG. 2a shows an example where, a single bracket is used with two mounting plates, to clamp/fit the fuel rail as well as the pipes to two fuel rail outlet. FIG. 2b shows a similar design to FIG. 2a except there is just one mounting plate. Thus in this design both the bracket (cradle) and the mounting plate are common to both the fuel rail and two pipes. FIG. 2c shows that the mounting plate is secured to the bracket/cradle with bolt/screw means. The shape of the cover plate may be varied as seen in FIG. 2d.

(12) FIGS. 3a and b shows an alternative examples. In these examples the clamping plate/means is not necessarily plate formed. Here the bracket or cradle 1 may be such that the common rail 2 protrudes from the bracket/cradle and the mounting fixing plate 3 is appropriately formed to accommodate the protruding portion of the common rail, and also have means to fix to the bracket/cradle. FIG. 3a shows a design similar to FIG. 2c but where the fuel rail extends protrudes outside the cradle and the mounting plate is appropriately formed. In FIG. 3b, the fixing portion/cover plate includes bores for connecting two pipes to two respective fuel outlets form the common rail, the fixing portion/cover plate including mean such as screw or bolt means to also fix the common rail to the bracket. A yoke 8 is used to fix and secure the two pipes to the fuel outlets, the yoke being secured to the cover plate by suitable means such as screw/bolt means. Thus this arrangement can be regarded as a dual yoke clamp.

(13) FIG. 4 shows how the designs of the FIG. 2 can be implemented and the figure shows an example of the complete rail is located, e.g. onto a cylinder engine block.

(14) FIGS. 5a and b shows an alternative example and how the rail may be clamped into a bracket/cradle arrangement by the high pressure pipe load. FIG. 5a shows a cross sectional view of an arrangement where the pipe is located into cradle 10b using bracket 10a. The cradle 10b is attached to the engine e.g. engine block. The bracket is provided by portions 10a and cooperates with cradle portion 10b. It is to be noted that the portion 10a and 10b may be regarded as two portions of the cradle or as the cradle with a co-operating bracket portion. The cradle portion 10b preferably includes at least two flat surfaces on the lower portion; an aligning surface 12 and a loading surface 13. The bracket also includes a bracket top portion 10a which includes a bore or guide to receive the pipe to the outlet in the fuel rail (from the fuel injector). Suitable tightening means such as screw or bolt means 6 are provided to secure the end of the pipe (from the individual fuel injector(s)) to the respective pipe outlet. The force from the pipe load on to the fuel rail will also secure the fuel rail to the lower portion of the cradle.

(15) FIG. 5b shows an isometric view of the FIG. 5ba arrangement with the upper clamping portion configured to receive and fit the ends of two pipes to respective fuel outlets in the fuel rail. In FIGS. 5a and 5b the lower portion of the cradle/bracket and the upper portion may be separate and preferably adjacent.

(16) FIGS. 6a and 6b show how the design of FIGS. 5a and b may be such that the upper and lower portions of the cradle bracket are formed such that surround the camshaft (rocker shaft). This example provides for greater utilisation of space. The arrangement also helps stabilise and or retain the camshaft. The pipes may be routed from the fuel outlets in the fuel rail under the cam/rocker shaft to the fuel injectors.

(17) According to some examples some of the them are self-fixture where they fixtures provide rail location and carry the weight of the railpotentially eliminating the need for additional tooling on the assembly line.