WO2017178721A1

WO2017178721A1 - Set of adaptable pipes for an additional-fluid reservoir of an internal combustion engine

Info

Publication number: WO2017178721A1
Application number: PCT/FR2017/050612
Authority: WO
Inventors: Sebastien Hureaux
Original assignee: Psa Automobiles S.A.
Priority date: 2016-04-11
Filing date: 2017-03-16
Publication date: 2017-10-19
Also published as: FR3050006A1; EP3443251A1; FR3050006B1

Abstract

The invention relates to an installation comprising filling (14) and venting (15) pipes coupled, on the one hand, to a reservoir for additional fluid, particularly SCR fluid and, on the other hand, to means of connection (25) to filling orifices accessible from the outside of an internal combustion, particularly diesel, engine vehicle. Each pipe (14, 15) has an internal axis defining an internal cross-sectional area bounded by the intersection between a plane perpendicular to and the pipe (14,). In this installation, the filling pipe (14) and the venting pipe (15) each comprise at least one rigid part (20, 22) and at least one part referred to as adaptable (21, 23) of semi-rigid structure able to provide a length and an orientation that are variable being able to adapt to suit various positions of the means (25) of connection to the filling orifices while at the same time maintaining, for any minimal cross section of this adaptable part (21, 23), a cross-sectional area substantially equal to a cross-sectional area situated in the rigid part (20, 22).

Description

ADAPTABLE TUBING ASSEMBLY FOR ADDITIONAL FLUID RESERVOIR OF INTERNAL COMBUSTION ENGINE

The invention relates to a set of filling and degassing pipes of an additional fluid reservoir for an internal combustion engine, these pipes being adaptable in length and / or orientation. In particular, the invention relates to the filling pipes and degassing of the tank of a nitrogen oxides reduction fluid, called "SCR", for the exhaust gas of a diesel engine vehicle. The adaptability of these tubes allows a workshop installation on almost all vehicles. The invention also relates to a motor vehicle with an internal combustion engine, in particular a diesel engine, equipped with such a set of pipes.

The invention relates to the field of tanks for containing an additional liquid for the fuel or the exhaust gas of an internal combustion engine. A particularly suitable application relates to the additional liquid called "SCR" (acronym for "Selective Catalytic Reduction" in English terminology) used for the selective reduction of nitrogen oxides NOx (usually NO and NO ₂ ) present in the exhaust gas. diesel engines. Such an SCR tank also comprises means for connecting a liquid filling pipe SCR and a degassing pipe which makes it possible to evacuate, during filling, the air or the gas contained in the tank SCR.

This gas to be discharged is partially produced by the hydrolysis of the liquid SCR under the influence of temperature, according to the formula:

CO (NH ₂ ) 2+ H ₂ O → NH ₃ + CO ₂

The degassing tubing, intended to evacuate the air and the urea and ammonia vapors thus produced, has a minimum internal diameter, of the order of 9 to 10 mm, to achieve evacuation quickly without overpressure. .

On the bodywork of a vehicle, the liquid filling port SCR is generally disposed on the vehicle body, in the same hatch and near the fuel filling port, while the tank of SCR liquid is placed in a lower part of this vehicle. The liquid filling pipe SCR thus connects the tank SCR to the filling port at the body via a connecting ferrule, while the degassing tubing connects the reservoir SCR to an end portion of the filler neck (located near the filler port).

An example of this type of assembly is presented with reference to the perspective view of FIG. 1. In this figure, a filler box 7, arranged on the body "C" by internal connection, has on its internal face 7i connecting blocks 7a to the filling pipes 1 and 4 respectively of fuel in the fuel tank 3 ( arrow F1) and additional liquid in the tank SCR 6 (arrow F5). The housing 7 houses the filling holes (not visible). The degassing tubes 2 and 5 respectively allow the evacuation of the gases from the fuel tank 3 (arrow F2) and from the gases of the additional liquid reservoir 6 (arrow F6). These pipes 1, 2, 4, 5 are fixed along the wheel passage 8 on the inner side.

During the assembly of a vehicle, the lower part of the vehicle - called "modular platform" - which mainly contains the chassis, wheels, engine and seats, is attached to its upper part of the vehicle - called "silhouette" - which mainly contains body parts. The modularity makes it possible to adapt different silhouettes on the same platform and thus brings more rationality to the assembly lines. In general, the liquid tanks are part of the modular platform, while the filling and degassing pipes are part of the bodywork, therefore the silhouette.

[0009] Various improvements have been made to the liquid tank installations to meet the safety constraints during filling. Thus, to block the exit of liquid in case of overturning of the vehicle, the patent document FR 2,686,048 proposes a degassing pipe provided with a flyweight blocking the liquid outlet through the degassing tubing. To prevent a backflow of liquid in the degassing pipe, patent FR 2 561 594 proposes blocking this discharge with a ball system. To achieve a substantial space saving above the tank, the degassing tubing is coupled in lateral position with the filler neck. An example of this type of coupling is presented in the patent application DE 10 2013 213 068. In this document, the degassing tubing of an SCR liquid tank is extended in the tank by a flared zone, this flared zone providing a additional space for the gaseous or condensed SCR fluid.

However, these improvements for the SCR liquid manifolds do not provide a solution to the adaptation of these pipes to any "platform and silhouette" pair in the assembly phase with a minimum number of different models. Indeed, the SCR pipes are currently dedicated to each pair "platform and silhouette" whereas, in the context of the standardization of the SCR installations, it would be advantageous for the same pipe to be used for different "flat" pairs. shape-silhouette ".

The invention aims to allow adaptation in length and angle of this manifold to different couples "platform and silhouette", while achieving a rapid evacuation and without overpressure of the gases while maintaining a minimum internal diameter to this manifold .

With such an adaptation, a small number of SCR installation tubing references may be sufficient for a large number of "platform - silhouette" pairs, which brings simplification and efficiency to the assembly lines.

In addition, the degassing tubing of a SCR installation must be able to easily evacuate the gases. Indeed, the liquid SCR evaporates easily and can crystallize at the connections between the pipes and the filler box, in particular when the adaptation of the pipes to the tanks is not optimized.

A good adaptation of the pipes to the boxes of different couples "platform - silhouette" is sought. To do this, the invention provides for the use of SCR fluid tubes adapted to deform while respecting the technical flow constraints due to this fluid. More specifically, the present invention relates to a set of pipes for an additional internal combustion engine fluid, comprising filling and degassing pipes coupled on the one hand to an additional fluid reservoir and, on the other hand, on the other hand, means for connection to filling ports, in particular accessible from the outside of the vehicle when the vehicle embeds these tubings associated with the tank. Each tubing has an internal axis defining a surface of internal section limited by the intersection between a plane perpendicular to the axis and the tubing. In this installation, the filler pipe and the degassing pipe each comprise at least one rigid part and at least one so-called adaptable portion of semi-rigid structure capable of providing a variable length and / or angular orientation while retaining, for example, any minimum section of this adaptable portion, a sectional area substantially equal to a section surface located in the rigid portion. The semi-rigid part of the pipes can thus be adapted to different positions of the connection means to the filling orifices without having to change tubings.

The invention also relates to any system integrating the tank with the tubing assembly described above associated with it, and any motor vehicle, with a motor (propulsion) thermal, gasoline or diesel type, integrating said system.

By "semi-rigid partite" is meant a portion of tubing composed of deformable zones distributed homogeneously in this portion, so as to be able to lengthen and curve respectively by a few centimeters (in particular up to 4 to 5 or 6 centimeters) and a few degrees (in particular up to 5 to 10 degrees), and rigid zones distributed in addition to the deformable areas to maintain a deformation of these areas without creating local internal voltage.

Under these conditions, the turbulence in the additional liquid filler neck are avoided and, in the degassing tubing, a good chemical exchange occurs between the additional liquid, the vapors of the liquid and the air.

According to particularly advantageous embodiments: the adaptable part comprises a bellows, this bellows has a periodic series of folded accordion-shaped surfaces defining a sequence of minimum sections remaining substantially constant during an adaptation in length and / or orientation of the bellows;

the adaptable part of the bellows is able to lengthen by at least 10%;

at least one spacer is also inserted in the adaptable part;

- The adaptable portion is a spiral wound tubing, such a tubing also allows a position adaptation by a variation in length and / or curvature without substantially altering the sectional area of the tubing;

the adaptable part comprises an extensible sleeve consisting of a tight mesh of metal braids;

the adaptable part has walls made of a material based on stainless steel, such a material being advantageously able to withstand the corrosion of acids or compositions derived from urea;

- The adaptable portion is secured to the rigid portion by mechanical means or adhesion selected from an adhesive joint, a thermoformed ring and a tight fitting;

the additional fluid is a selective catalytic reduction fluid of the SCR type.

Other data, features and advantages of the present invention will appear on reading the following nonlimited description, with reference to the appended figures which represent, respectively:

- Figure 1, a perspective view of the fuel filling and degassing pipes and additional SCR liquid between the tanks and the filling holes (already commented);

FIGS. 2a and 2b are perspective and sectional views of the filling and degassing pipes of an SCR tank with adaptable parts comprising a compressed bellows;

- Figures 3a and 3b, perspective and sectional views of the filling pipes and degassing SCR tank with adaptable parts comprising the bellows stretched; FIG. 4 is a front view of an example comprising an adaptable portion of the SCR filling pipe constituted in spirals, and

- Figure 5, a perspective view of a bellows filler neck mounted at two angles of different orientations.

In the figures, identical or corresponding elements are identified by a same reference sign which refers to (x) passage (s) which describes (s) such an element. The qualifiers "inside", "internal" or "outside" refer to the relative position of elements with respect to the motor vehicle or tubing referred to.

Referring to Figure 2a, is shown the diagram of an example of filling pipe 14 and additional degassing pipe 15 additional liquid SCR. The filling pipe 14 comprises in this figure two fixed length portions 20 connected - via thermoformed rings 16 - with a portion of variable length 21 formed by a bellows. Similarly, the degassing tubing 15 has two fixed length portions 22 coupled via thermoformed rings 16 by a variable length portion 23 formed by a bellows. These two tubes 14 and 15 are advantageously made of high density polyethylene "HDPE".

The filler neck 14 extends to the ferrule 25 for coupling to connection means of a filler box filling port (see reference 7 of Figure 1). The tubing 14 is fixed by a lug 27 to the vehicle body and by the clip 26 to the fuel filler neck (referenced 1 in FIG. 1), the ferrule 25 being attached to the means by the fuel filler box (reference 7 in Figure 1).

Figure 2b shows, in section, the bellows 23 of the degassing tubing 5 of Figure 2a. In this figure, the bellows 23 has an internal axis XX 'and an internal diameter d2 equal to the internal diameter d1 of the rigid portion. This bellows is tightened and the length "L1" of the bellows 23 is substantially minimal, the bellows 23 then being compressed. This diagram also similarly illustrates the bellows 21 of the filler neck 14 in the compressed state. The bellows 23 consists of a set of convolutions 30 forming a succession of folded surfaces accordion defining a succession of vertices 31 pointing outwardly of the bellows 23, and roots 32, oriented towards the inside 23i of the 23. The set of roots 32 forms a series of minimum sections defining an inner surface 33 (dashed lines ^ arranged in alignment with the inner surface 34 of the fixed length portion 22. The alignment of these surfaces 33 and 34 forms a continuous cross-sectional area offered to constant-size vapor flow, liquid or SCR gas, which eliminates or reduces the risk of turbulence and pressure drop.

Figure 3a shows a diagram of the filling pipes 14 and degassing 15 similar to that of Figure 2a, but wherein the bellows 21 and 23 are stretched. The elongation is of the order of 40 mm for the two tubes 14 and 15. This elongation thus allows great modularity within a styling chain for different silhouettes.

In addition to Figure 3a, the view of Figure 3b shows the bellows 23 of the degassing tubing 15 seen in section once stretched. In this Figure 3b, the length "L2" of the bellows 23 is substantially elongated about 40 mm from its compressed conformation of Figure 2b, an elongation rate of up to about 20% in the example. Depending on the size and mechanical properties of the bellows, elongation rates can vary between 10 and 30% or more.

The alignment of the surface 33 defined by the roots 32 of the convolutions with the inner surface 34 of the fixed length portion also allows the gas to provide a constant section for their flow. This diagram also represents, in a similar way, the stretching of the bellows 21 of the filler neck 14.

Figure 4 shows the diagram of an adaptable portion formed of a pipe 40 consisting of a series of spiral convolutions 41 contiguous and inclined. This spiral tube 40 ends with two linear ends 42 connected to the rigid parts 20 via thermoformed rings 16. The spirals 41, the linear parts 42 and the rigid parts 20 have sections of substantially identical surface. The adaptable portion allows, according to the invention, not only to obtain a length of tubing 14 or 15 variable in length, as shown in the previous figures, but also in curvature to allow adaptation in orientation.

Such an angular adaptation is illustrated by the perspective view of Figure 5 which relates to the filler pipe 14 can be mounted on a filler box 7 (see Figure 1), in two different directions corresponding to two positions "A" and "B" forming an angle "a" in the illustrated example. To move from the "A" position to the "B" position, the adaptable part 10 is formed of a sleeve that can bend to deport the tubing 14 by an angle "a", for example equal to 7 to 8 degrees , without creating internal mechanical tension. Such a sleeve 10 is formed in the example illustrated by a tight mesh of metal braids, but may also be constituted by the bellows 21 (Figures 2a and 3a), the spiral pipe 40, or a metal spiral covered with a envelope made of flexible material.

This angular adaptation is obtained by stretching on one side and compression on the opposite side of the sleeve 10, for example convolutions 30 (FIG. 2b) or 41 (FIG. 4), respectively of the bellows 23 (or the bellows). 21) and the spiral tubing 40.

The invention is not limited to the embodiments described and shown. Thus, one or more "C", "U" or "omega" configuration spacers are (or are) also inserted into the adaptable part, in order to maintain a constant gap between the sections of minimal surface.

Furthermore, the invention could be used in the case of a fuel engine, placed in a building, in a locomotive or in a ship, and also requiring a reservoir and additional liquid lines, particularly SCR type.

Claims

1. System comprising a reservoir of fluid, in particular additional fluid, (6) associated with a set of pipes for an internal combustion engine fluid (C), said set of pipes comprising filling pipes (14) and degassing pipes (15) coupled on the one hand to said fluid reservoir (6) and, on the other hand, to connecting means (25) to filling ports, in particular accessible from the outside of a vehicle (C) carrying said system, each manifold (14, 15) having an internal axis (XX ') defining an inner section area limited by the intersection of a plane perpendicular to the axis (XX') and the tubing (14, 15), characterized in that the filler neck (14) and the degassing tubing (15) each comprise at least one rigid portion (20, 22) _. and at least one so-called adaptable portion (21, 23; 40; 10) of semi-rigid structure providing a variable length (L1; L2) and / or angular orientation (a) and having for any minimum section of this adaptable portion ( 21, 23), a cross-sectional area substantially equal to a sectional area in the rigid portion (20, 22).

2. System according to claim 1, wherein the adaptable portion (21, 23) comprises a bellows (21, 23), this bellows having a series of folded surfaces accordion defining a sequence of minimum sections which remain substantially constant when an adaptation in length and / or orientation of the bellows.

3. System according to the preceding claim, wherein the adaptable portion (21, 23) is able to elongate by at least 10%.

4. System according to any one of claims 2 or 3, characterized in that it comprises at least one spacer inserted into the adaptable part (21, 23).

The system of claim 1, wherein the adaptable portion is a spirally wound tubing (40).

6. System according to claim 1, wherein the adaptable portion comprises an extensible sleeve (10) consisting of a tight mesh of metal braids.

7. System according to any one of the preceding claims, wherein the adaptable portion (21, 23) has walls made of a stainless steel material.

8. System according to any one of the preceding claims, wherein the adaptable portion (21, 23) is secured to the rigid portion (20,22) by mechanical means or adhesion selected from a glue joint, a ring thermoformed (16) and a tight fit (1 6).

9. System according to any one of the preceding claims, wherein the fluid is an additional fluid, in particular a selective catalytic reduction fluid.

10. Motor vehicle with internal combustion engine, including gasoline engine type or diesel engine, characterized in that it comprises at least one system according to any one of the preceding claims.