WO2006056724A1

WO2006056724A1 - Motor vehicle engine comprising a continuous diesel fuel collection surface

Info

Publication number: WO2006056724A1
Application number: PCT/FR2005/050995
Authority: WO
Inventors: Jean Michel Detouche; Fabrice Boisadan
Original assignee: Renault S.A.S
Priority date: 2004-11-26
Filing date: 2005-11-28
Publication date: 2006-06-01
Also published as: EP1819925A1; JP2008522073A; FR2878577A1; FR2878577B1; KR20070086114A

Abstract

The invention relates to an internal combustion engine which is intended, for example, for a motor vehicle. The inventive engine comprises a cylinder head (20), injectors (40) and pressurised fuel feed pipes (44). The engine also comprises a sealed chamber (10) which is used to contain fuel leaks and which is defined by an essentially-lower wall (14, 18) and an essentially-upper wall (12), such that the upper ends of the injectors are inside the chamber. In addition, the chamber is equipped with at least one fuel discharge port. The invention is characterised in that the essentially-lower wall (14, 18) is shaped such that the fuel can flow from at least one injector (40) to at least one other injector (40) and in that the drain opening is positioned such as to collect fuel that has flowed through the chamber.

Description

Motor vehicle engine with continuous gas collection surface.

The present invention relates to an internal combustion engine, in particular a motor vehicle.

The present invention relates more particularly to an internal combustion engine, typically comprising a cylinder head, fuel injectors passing through the cylinder head, and pressurized fuel supply conduits connected to the injectors. In this type of engine, it has been found that fuel leakage can occur at the connection between each supply duct and the associated fuel injector.

However, given the pressure at which it is soumi the fuel, which may be greater than 1000 bar, the fuel leaks in a spray form that is easily flammable.

The pulverized fuel is likely to come into contact with engine components which have a relatively high temperature, which can cause fire to begin.

The fuel can also sprinkle bodies with safety functions such as the brake system, which presents a safety risk.

The invention aims in particular to provide a solution to this risk of uncontrolled leakage that is so mple, effective, and economical.

The invention aims in particular to provide an easily adaptable solution on a given engine block, which solution is nevertheless effective on all the injectors concerned.

For this purpose, the invention proposes an internal combustion engine, particularly a motor vehicle, comprising a cylinder head, injectors and pressurized fuel supply lines, the engine further comprising a closed chamber for the containment of leaks of fuel. fuel which enclosure is delimited by a generally lower wall and a generally upper wall so that the upper ends of the injectors are located inside the enclosure, the enclosure further having at least one fuel outlet.

According to an advantageous aspect of the invention, the generally lower wall is shaped to allow the fuel to flow from at least one injector to at least one other injector and the flow orifice is positioned to collect fuel. having thus circulated in the enclosure.

According to an advantageous variant, the generally lower wall is inclined towards the flow orifice so as to promote the flow of the fuel contained in the chamber towards the flow orifice.

Preferably, the enclosure has a single flow orifice.

Advantageously, a discharge duct extends from said at least one flow orifice, which exhaust duct is an independent piece attached to the enclosure assembly.

According to a preferred aspect, a chamber is located above the cylinder head which chamber contains a camshaft and an oil bath in which the camshaft bathes and the chamber is covered by a cover, the enclosure for the fuel leak containment being mechanically associated with said chamber cover containing the camshaft.

According to an advantageous variant, the lower wall of the fuel leak containment enclosure is at least partially merged with said cover of the chamber containing the camshaft.

Preferably, at least one seal seals at least one element passing through a wall of the fuel receiving enclosure.

Advantageously, a joint ramp consists of a series of annular seals substantially aligned in a series of languages integrally formed with these annular seals and connects the annular seals to each other.

In a preferred aspect, a high pressure fuel supply chamber and a series of fuel lines are each connected to one side of this chamber at each time with a connection zone therewith, the junction ramp being positioned such that the individual annular seals each surround a respective connection zone between a pipe high pressure and the room.

According to an advantageous variant, the fuel collection chamber consists of a cover and a bowl connected to each other by their respective peripheral edges, one of the two elements among the bowl and the cover having at least one notch at or calf of its edge, which notch forms a through passage for a member penetrating into the enclosure, a seal being placé in said at least one notch, which joint has a through passage and a slot extending from the passage to an edge portion of the seal, said edge portion connected by the slot being placed to be housed in the bottom of the notch which receives the seal.

Other features and advantages of the invention will appear on reading the following detailed description of non-limiting embodiments for the understanding of which reference will be made to the appended drawings in which:

- Figure 1 is a schematic sectional view of a gas oil collection chamber according to the invention;

- Figure 2 is an exploded perspective view of a gas oil collection chamber according to the invention, this perspective being seen from a first side;

FIG. 3 is an exploded perspective view of a fuel collection chamber according to the invention, this perspective being seen from a second side;

FIG. 4 is a perspective view of a first seal in accordance with an embodiment of the invention;

- Figure 5 is a perspective view of a second seal adapted within the scope of the invention. In Figure 1, there is shown two main elements constituting an enclosure 10 according to the invention for the collection of fuel. The two elements here are a hood 12 and a bowl 14a.

Figure 1 shows in section the cover 12 and the bowl 14a at their location relative to a base 20.

A space 30 is formed above the yoke 20 and below the enclosure 10 to contain a camshaft 32 and an oil bath 34 in which the camshaft 32 bathes.

This space 30 is delimited below by a hollow shape 20a open towards the top, constituted by the same material of the base 20, which conventionally covers a cylinder 21.

The space 30 is further defined superiorly by a cylinder head cover 14b also called "hat housing" or "cylinder head cover". The bowl 14a and the cylinder head cover 14b are constituted by the same element 14. In other words, the bottom cover 14b delimits by its lower surface the lubrication space 30 of the camshaft 32, and delimits by its upper surface the chamber 10 for collecting gas oil.

To this end, the cylinder head cover 14b has lateral walls 15 extending downwards, so as to have a cap shape above the cam lube space 30. It furthermore has side walls 16 which extend upwardly and have a concave shape forming the bowl 14a of the gasoline collection chamber 10. The fuel collection chamber 10 here equips an internal combustion engine which is of the four-cylinder diesel type. line .

In this way, four diesel injectors 40 are present which each equip a respective cylinder. The injectors 40 are distributed in an aligned manner in a longitudinal direction to the gasoline collection chamber 10, as shown in FIG. 2.

The injectors 40 extend through the assembly consisting of the cylinder head 20, the lubrication space 30 of the camshaft 32, and also through the cylinder head cover 14b, that is to say the bowl 14a. . The injectors 40 thus extend from the underside of the cylinder head 20, that is to say the inside of a combustion cylinder 21, until they come out at their upper end into the chamber 10 for collection. of diesel. Each injector 40 therefore has an upper end which is positioned above the adjacent upper face of the bowl 14a.

According to the embodiment shown in FIGS. 2 and 3, an end 46 of each supply line 44 and the upper end of each injector 40 meet and form at this point a connection zone 48 equipped each time with a tightening nut 49.

In accordance with the teachings of the invention, the enclosure 10 is closed for the containment of any fuel leaks that may appear at these connection zones.

48 between supply duct 44 and injector 40.

As shown in Figure 1, the bowl 14a is adjacent thereto by its peripheral edge 14c to a peripheral edge 13 of the upper cover 12, to which it is sealingly attached. These two borders 13, 15 both have a plane margin (or peripheral rim) at least partially describing the peripheral rim, which margins come opposite one another and receive between them a seal of periphery 50 (FIG. 1) which is sandwiched there by suitable bolting. Preferably, the cover 12 is made of a plastic or elastomeric material.

Each of the four supply lines 44 which equip the injectors 40 is supplied with pressurized gas oil by a rail 60 which has substantially the shape of a cylindrical tube. This high-pressure channel 60 is placed under the bowl 14, more precisely under a longitudinal portion of its peripheral rim. Each of the four supply lines 44 joins the high pressure rail 60 at the side of the latter, forming in each case at this point a connection zone 61 secured by a clamping nut. Another Line 47 joins the high-pressure rail 60. This line 47 or pressurizing line serves to supply the stream 60 with pressurized gas oil. This pipe 47 also has a connection zone referenced 47a with the rail 60, also equipped with an associated clamping nut.

Each connection zone between the rail 60 and a supply pipe 44 or between the rail 60 and the pressurizing pipe

47 is located at the surface of the bowl 14. More precisely, the bowl 14 has a series of through orifices which each receive a connection zone 61 of a pipe 44, 47 with the rail 60. fuel supply of each of the injectors

48 is made in particular by crossing these various orifices formed in the bowl 14.

Each of the orifices has a width greater than the width of the connecting nut 61, leaving a free space around the nut 61.

This free space located around each clamping nut 61 is each filled by a circular seal 71, 72, 73, 74, 75 visible in Figure 2. The seals are part of the same elastomer part 70, called here ramp joints. This joint ramp 70 consists of the series of circular seals 71, 72, 73, 74 and 75 between which are distributed a series of connecting languages 76, 77, 78, 79. These linking languages 76, 77, 78, 79 have between the seals a spacing equal to the spacing between the supply lines 44, 47 at their connection with the high pressure channel 60.

This joint ramp 70 is sandwiched between the high-pressure rail 60 and the lower surface of the bowl 14, compressed between these two elements by the tightening of the nuts which connect the supply lines 44 as well as the control line. pressure

47 to the high pressure rail 60.

The pressurizing line 47 describes a path in the chamber 10 and passes through one of the walls 16 in direction of a source of gas oil not shown. It crosses for that the peripheral edge 13 of the cover 12, through a first notch 17a formed in the edge 13 at the longitudinal end portion thereof. This notch 17a is of a width greater than the diameter of the pressure line 47. There is therefore a free space between the contour of the pipe 47 and the notch 17a, which free space is here filled by a seal 80 The contour of the seal 80 is complementary to the inner shape of the notch 17a.

This seal 80 visible in Figure 4 has a substantially triangular body. At one of the peaks 81 of this triangle is formed a slot 82, which slot 82 is extended by a central housing 83 for receiving the pressurizing pipe 47. The edges of the slot 82 can be removed to allow the pipe 47 to be introduced into the central passage 83 of the joint 80.

The split top 81 is the one that is intended to be placed at the bottom of the notch 17a.

As a result, the slot 82 is naturally closed by the lateral bearing forces produced by the edges of the notch 17a on the triangular body of the seal 80.

The seal 80 is extended, on an edge which is opposite its split top 81, by two tongues 84 which extend transversely and on either side of the plane of the triangular body. These two languages 84 are intended to be clamped between the two associated edges of the cover 12 and the bowl 14 to secure in place of the seal 80 by mutual compression. The cover 12 is further provided with a second notch 17b visible in Figure 2 for the passage of an electrical conductor bundle 90a for controlling the injectors 40 (Figure 3). This notch 17b is in the vicinity of the notch 17a described above. Also, the notch 17b is of greater dimensions than the seal of conductors that passes through it. To fill the free space around the conductor 90a in the notch 17b, the conductor seal crosses a seal, referenced 90 in the figures.

This seal 90 visible in Figure 5 also has a triangular body with a slot 92 located near one of its highs. This is again summit 91, which is intended to come to the bottom of slot 17b. This seal 90 comprises two through passages 94, 95. One of these passages is joined by the slot 92. The other 95 of these passages, of smaller diameter, is connected to the first passage by a slot of link 96 lying between the two passages 94, 95.

A first, not shown, conductor beam passes through the second passage 95 and is in place through this link slot 96 after having been preliminarily placed in the first passage 94 from the first slot 92.

The seal 90 is further provided on each of its sides with a substantially cylindrical extension portion 97 disposed in extension of the first passage 94 for the conductive bundle 90a. This cylindrical portion 97 has a double slot 98 thus forming two half-cylinders. As a result, the two half-cylinders 99 can be separated from each other in association with the edges of the passage 94 when the conductive bundle 90a is put in place.

This cylindrical portion 97 placed in extension of the passage 94 is intended to accentuate the mechanical strength of the electrical conductors which are flexible elements and therefore capable of movement during the life of the vehicle.

This cylindrical extension part 97 is advantageously equipped with a circumferential ring element for an assured maintenance of the conductor 90a.

Thanks to the joints 50, 80 and 90, the enclosure 10 is completely sealed and collects the gasol l reliably, including it when it leaks in the form of a spray jet at high pressure to the most areas. 10. The fuel is deposited in the lower part of the bowl 14 before being conveyed out of it.

The lower part of the bowl 14 comprises a slope 18a which descends from an overhanging part 18b surrounding the zones of Connection 61 to a continuous surface 18c, below, extending around the injectors 40 (Figures 2 and 3).

The lower portion 18 of the bowl 14 is thus in particular in the form of a surface 18c which is continuous over a wide extent, from the injector at one end to the injector at the opposite end. .

This surface 18c surrounds each of the connection zones

48 of injectors 40, and meets no obstacle vis-à-vis of a flow of diesel between them. The bowl 14 thus forms a surface 18c for receiving the gas oil which is hydraulically common to all the injectors.

In other words, the diesel can circulate on this continuous surface

18c of an injector to its neighbor injector, and this, in the present preferred embodiment, for all the injectors in the presence. This particular constitution is found to increase the efficiency of the fuel collection function by the enclosure 10. Indeed, the flow of gas oil out of the enclosure is reliable because the flow is suj and no clogging or other insufficiency of flow. The reliability of the device is further ensured for this reason for each of the injectors concerned.

In combination with this increased efficiency, use is made here of a single gasoline outlet 100 in the enclosure 10 and a single discharge pipe 1 10 of the gas oil.

The continuous surface 18c of the bottom of the bowl 14 is preferably inclined towards the flow orifice 100 so as to promote the flow of the fuel out of the bowl 14.

The evacuation pipe 1 10 is provided to drive the gasol l to a diesel storage tank or to a pipe of the engine supply circuit so that the gas oil is directly recycled. The tank may be a dedicated tank for recovering the leaking fuel, or the main fuel tank of the vehicle. This duct 110 is made here in the form of a piece independent of the rest of the device. In other words, it is connected to the hood 12 at the stage of assembly.

The discharge pipe 110 is provided with a first fastener 111 attached to the cover 12 and a second fastener 112 attached to another member not shown. These fasteners 111 and 112 allow attachment to other elements of the engine block which are not shown in the figures, but which are for example an element of the engine block or a frame member of the vehicle.

Claims

1. Internal combustion engine, especially a motor vehicle diesel engine, comprising a cylinder head (20), injectors (40) and supply lines (44, 47) in pressurized fuel, the engine further comprising a closed chamber (10) for the containment of fuel leaks which enclosure (10) is delimited by a generally lower wall (14, 18) and a generally upper wall (12) so that the upper ends of the injectors (40) are the interior of the enclosure (10), the enclosure further having at least one fuel outlet (100), characterized in that the generally lower wall (14, 18) is shaped to allow the fuel circulating from at least one injector (40) to at least one other injector (40) and in that the flow orifice (100) is positioned to collect fuel thus circulating in the enclosure .

2. Engine according to claim 1, characterized in that the generally lower wall (14, 18) is inclined towards the outlet (100) so as to promote the flow of the fuel contained in the enclosure to the flow port (100).

3. Engine according to claim 1 or claim 2, characterized in that the enclosure (10) has a single outlet (100).

4. Engine according to any one of the preceding claims, characterized in that it has an evacuation duct

(1 10) extending from said at least one outlet (100), which exhaust duct (1 10) is an independent piece attached to the enclosure (10) mounting.

5. Motor according to any one of the preceding claims, characterized in that it comprises a chamber (30) located above the cylinder head (20) which chamber contains a camshaft (32) and an oil bath. (34) in which the camshaft (32) is immersed and which chamber (30) is covered by a cover (14), the enclosure for the containment of fuel leaks (10) being mechanically associated with said cover (14) of the chamber (30) containing the camshaft (32).

6. Engine according to the preceding claim, characterized in that the bottom wall of the fuel leakage enclosure (14) is at least partially coincides with said cover (14) of the chamber containing the camshaft (32). ).

7. Motor according to any one of the preceding claims, characterized in that it comprises at least one seal (50, 80, 90) which seals at least one element passing through a wall (12,

14) of the fuel receiving enclosure (10).

8. Motor according to the preceding claim, characterized in that it comprises a joint ramp (70) constituting a series of annular rings (71, 72, 73, 74, 75) substantially aligned with a series of languages ( 76, 77, 78, 79) integrally formed with these annular seals and connecting the annular seals to each other.

9. Motor according to the preceding claim, characterized in that it comprises a high pressure fuel supply chamber (60), and a series of fuel lines (44, 47) which are each connected to one side of this chamber (60) at each end of a connection zone therewith, the joint ramp (70) being arranged such that the various annular seals (71, 72, 73, 74, 75) surround each a respective connection zone between a high-pressure pipe (44, 47) and the chamber (60).

10. Engine according to any one of the preceding claims, characterized in that the fuel collection chamber (10) comprises a cover (12) and a cup (14) interconnected by their respective peripheral edges (13, 14c). ), one of the two elements among the bowl (14) and the hood (12) having at least one notch (17a, 17b) at its edge (13), which notch (17a,

17b) forms a through-passage for an element penetrating the enclosure, a seal (80, 90) being placed in said notch (17a, 17b), which seal (80, 90) has at least one through-passage (83, 94 , 95) and a slot (82, 92) extending from the passage (83, 94, 95) to an edge portion of the gasket, said edge portion connected by the slot (82, 92) being placed to become lodged in the bottom of the notch (17a, 17b) which receives the gasket.