Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
  • F02M37/0011—Constructional details; Manufacturing or assembly of elements of fuel systems; Materials therefor
  • F02M37/0017—Constructional details; Manufacturing or assembly of elements of fuel systems; Materials therefor related to fuel pipes or their connections, e.g. joints or sealings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
  • B60K15/01—Arrangement of fuel conduits
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
  • B60K15/03—Fuel tanks
  • B60K15/035—Fuel tanks characterised by venting means
  • B60K15/03504—Fuel tanks characterised by venting means adapted to avoid loss of fuel or fuel vapour, e.g. with vapour recovery systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
  • F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
  • F02M25/089—Layout of the fuel vapour installation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/22—Multi-channel hoses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L9/00—Rigid pipes
  • F16L9/18—Double-walled pipes; Multi-channel pipes or pipe assemblies
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
  • F02M37/0047—Layout or arrangement of systems for feeding fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L2011/047—Hoses, i.e. flexible pipes made of rubber or flexible plastics with a diffusion barrier layer

Definitions

• the invention relates to fluid lines made of plastic, in particular but not exclusively to the lines used to connect the fuel tank of a vehicle to the engine of this vehicle.
• the invention relates more particularly to the fluid lines (in the liquid state or in the gaseous state) fitted to motor vehicles and mention may be made, in addition to the fuel lines, of the lines associated with various fluids to liquid state or mixtures of liquids (lubricants, coolant, windshield washer fluid, etc.), or gaseous (cooling gas for air conditioning for example).
• Another solution consists in providing an internal partition wall defining passages, the assembly being single-layer and of the same thickness, as described in documents FR-A-2 293 652 and FR-A-2 511 747.
• This assembly lends itself better to bending, but its performance in terms of permeability remains limited, and an assembly made of multi-layer material would be both complex to manufacture and very expensive. It therefore appears a need to be able to have fluid pipes made of plastic material, which are both efficient and of low manufacturing cost.
• the object of the invention is to design a fluid pipe which is both efficient and of low manufacturing cost, while lending itself particularly well to the case of fuel for vehicles equipped with an injection, petrol or diesel.
• a fluid pipe made of plastic in particular for connecting the fuel tank of a vehicle to the engine of said vehicle, characterized in that it is constituted by an outer tubular wall made of a material multi-layers, said material comprising an internal layer with low permeability to the fluid concerned and an external protective layer, and by an internal partitioning arranged inside this external tubular wall to delimit a plurality of passages, said partitioning being meanwhile made of a single-layer material compatible with said fluid.
• the multi-layer material constituting the outer wall further comprises a layer of adhesive between the inner and outer layers of said outer wall.
• the multi-layer material constituting the external wall comprises an intermediate layer forming a barrier with regard to at least one of the components of the fluid concerned.
• the multi-layer material constituting the outer wall further comprises a layer of adhesive between the intermediate layer forming a barrier and the outer protective layer.
• the inner and outer layers of the outer wall can for example be made of polyamide.
• the single-layer material constit ⁇ tive of the interior partitioning is chosen from the group comprising polyamides, polyethylene, polypropylene, and recycled materials from the aforementioned materials. It is also possible to provide that the single-layer material constituting the interior partitioning further comprises additional charges, such as a graphite charge intended to make this interior partitioning conduc ⁇ tor electricity.
• the interior partitioning is at least partially integral with the inner layer of the outer wall.
• the interior partitioning consists of an inner tubular wall held coaxially in the outer tubular wall by spacing fins which extend radially along the axis common to the two walls.
• the interior partitioning consists of a transverse internal veil.
• the interior partitioning consists of three webs extending radially from the axis of the exterior wall.
• the three sails meet at the axis of the outer wall, and define three dihedra whose angles are respectively 116 °, 116 ° and 128 °, or even define three dihedra of the same angle.
• the interior partitioning is constituted by an inner tubular wall with a transverse internal veil held coaxially in the outer tubular wall by spacing fins which extend radially along the axis common to the two walls.
• the internal partitioning consists of two internal walls which are distant from each other and which, with the external tubular wall, delimit two lateral passages and a central passage.
• each internal wall ' is connected directly to a partial internal layer of the external wall, so as to form a continuous wall having in section a substantially circular shape, the residual parts of this external wall then forming two connecting fabrics which are made of multi-layer material.
• FIG. 1 is a schematic overview an installation equipping a motor vehicle for connecting the fuel tank to the injection engine of this vehicle, said installation comprising a pipe in accordance with the invention, allowing both, and over the main length of the path concerned, the passage of fuel d 'supply and return fuel;
• FIG. 2a and 2b illustrate in transverse section (section along II-II of Figure 1), and on a much enlarged scale, two possible variants of pipes according to the invention, respectively with integral spacing fins of the outer wall (which here comprises three layers), or with fins of space ⁇ ment integral with the inner wall, the outer wall in one case four layers;
• - Figures 2c and 2d are other sections according to II-II illustrating two other variants, the interior partition of which is defined by a transverse internal veil;
• FIG. 2e and 2f illustrate two other variants, with internal partitioning formed by three radial sails, the angular arrangement of which is here provided for the case where the fuel is diesel;
• FIG. 3 is an overall view schematically an installation which differs slightly from that of Figure 1, insofar as the fuel line also allows the passage of fuel vapors from the reser ⁇ see;
• FIG. 4a and 4b illustrate in transverse section (transverse section IV-IV of Figure 3), and on a very enlarged scale, two possible variants of pipes, respectively with an outer wall with three layers and four layers;
• FIGS. 4c and 4d are other sections on IV-IV illustrating two other variants whose internal partitioning is different; - Figures 4e and 4f illustrate two other variants, with internal partitioning formed by two internal walls spaced from one another, of semi-circular shape.
• FIG. 1 illustrates an installation intended to equip a motor vehicle, for connecting the fuel tank 10 to the injection engine 11 of this vehicle.
• the representation of this installation most of whose components are already known, has the main purpose of locating the fuel line 100 used in this installation, which line has a particular structure, in accordance with the invention, which will be described below in referring to Figures 2a to 2f.
• the fuel tank 10 thus comprises a fuel pump 12, equipped with a suction plate 13 on which are connected two pipe portions 14 and 15, one of which is used to supply the engine with the fuel thus sucked , and the other on the return of excess fuel exiting downstream from the injection rail of this engine.
• a single pipe 100 which is connected to the sections 14 and 15 by a suitable fitting 101.
• a similar fitting 102 At the other end of the fuel pipe 100, there is a similar fitting 102, from which two sections of pipe 16 and 17, the first serving to supply the engine with fuel, and the other for returning excess fuel.
• the pipe section 16 is equipped with a fuel filter 18, but it goes without saying that such a filter could as well be arranged on the starting section 14 in the vicinity of the tank.
• the fuel sucked by the pump 12 from the reservoir 10 passes through the pipe section 14, then enters the pipe 100, to finally arrive at the supply section 16 leading to the engine injection rail.
• the liquid borrows the section 17, then, from the connector 102, also passes through the aforementioned line 100, to finally leave it, downstream of the associated connector 101, opening into the return section 15 connected to the suction plate 13 and finally to the tank 10.
• the pipe 100 is formed by two tubular walls 110 and 120, which are essentially coaxial and kept at a distance from one another by spacing fins 112 (here three in number ).
• These two tubular walls 110 and 120 are here of circular section, but this is of course only an example, and one can provide other forms of sections preferably admitting a center of symmetry.
• the axis common to the two walls 110 and 120 is here referenced X.
• the interior wall 120 thus delimits a central passage 121
• the exterior wall 110 defines, with this interior wall, an annular passage 111, the passages 121 and 111 thus delimited allowing to channel two different fuel flows.
• the inner tubular wall 120 and the spacing fins 112 thus define a partitioning interior, which is made of single-layer material compatible with the fluid concerned.
• the spacing fins 112 are integral with the outer wall 110, and extend radially along the axis X so as to ensure, by their free edge 112.1, the maintenance of the inner wall 120 in the outer wall 110.
• the inner wall 120 is therefore here desoli ⁇ arized from the unitary assembly constituted by the outer wall 110 and the spacing fins 112, which is advantageous when it comes to bending the pipe, in the extent that the radially outer fibers of the spacing fins and of the outer wall are subjected to less tensile forces in the case of a radius of small curvature.
• the outer wall 110 is also made of a multi-layer material, that is to say consisting of at least two layers, with an internal layer with low permeability to the fluid concerned and a protective outer layer.
• the multi-layer material thus comprises an internal layer 113 with low permeability to the fuel concerned and an external layer 114 intended to provide mechanical and possibly also chemical protection.
• FIG. 2a Another particular case has been illustrated in FIG. 2a where there is provided, between the layers 113 and 114, an intermediate layer 115 forming a barrier facing at least one of the components of this fuel.
• the outer wall 110 thanks to its multi-layer structure, thus ensures for the pipe 100 both the low permeability with respect to the fuel, and the mechanical resistance to external aggressions.
• the intermediate barrier layer 115 is protected by the adjacent layers, both against attack by the fuel (through the wall 113) and against external attack, of mechanical or chemical type (through the wall 114).
• the material constituting the intermediate layer forming a barrier a material of the type commonly used in the food sector, since this material is in no case in direct contact with the fuel.
• the choice of the material constituting the other layers may allow them to fulfill an additional barrier function (in particular with regard to other fuel components)
• the internal layer 113 and the external layer 114 of the external wall 110 are made of polyamide.
• the inner layer 113 provision may in particular be made of a polyamide 6, 6-6, 11 or 12, and for the outer layer 114, a polyamide 12 or 11.
• 1 'We can also provide a varnish or an outer protective layer, forming a cladding surrounding the outer layer 114, for example in a rubbery material, which allows in the case of such an application to further improve the behavior in temperature (which is particularly advantageous when the fuel line passes in the vicinity of the engine), than with regard to the anti-shock qualities of this line.
• spacing fins 112 may be integral with the inner layer 113 of the outer wall, this solidarity advantageously resulting from the same coextrusion of the corresponding profile. These fins are then produced polyamide.
• the inner wall 120 has the sole function of constituting a partition, delimiting the central passage 121 and the annular passage 111. These passages are both used by the same fuel, so that we have managed to overcome completely any permeability constraint for the inner wall 120 of the pipe 100.
• This inner wall is also completely protected by the above-mentioned outer wall 110, so that any constraint of mechanical resistance is overcome. Therefore, it is possible to use less "noble" materials to make this interior wall 120. It will in particular be possible to use a single-layer material such as polyamide, high density polyethylene, polypropylene , or a recycled material from the aforementioned materials. It is therefore easily understood that the unit cost of such a pipe is considerably reduced due to the few constraints for the inner wall 120 of this pipe, which wall must only have sufficient resistance to fuel, which is easy to obtain with the aforementioned materials.
• the material constituting the interior wall 120 also comprises additional charges, such as graphite charges intended to make this interior wall conductive of electricity.
• the inner wall 120 provides an additional anti-static function for the fuel line.
• the absence of rigid constraints for the production of the internal wall 120 furthermore makes it possible to provide a wall of small thickness, notably smaller than the thickness of the external wall 110 which is in turn made of a multi-material. layers.
• a thickness at most close to 0.5 mm for the interior wall 120, while the exterior wall 110 will present in practice a thickness close to 1 mm.
• the interior wall 120 additionally behaves like a central core for the exterior wall 110, so that this interior wall also contributes to effectively combating any risk of "cracking" of the pipe in the event of '' bending the pipe with very small radii of curvature.
• Such a risk of crunching was particularly sensitive in the context of conventional pipes of the single-layer type, and the possible sheathing of two juxtaposed pipes did not prevent this risk.
• the passages 111 and 121 may in certain cases prove to be advantageous to prefer one passage rather than the other. This is so for example in the present case where the line 100 is used to connect the fuel tank of a vehicle to the engine of said vehicle, using the central passage 121 to channel the supply fuel, and the annular passage 111 for the return of excess fuel to the tank. Indeed, we know that certain fuels are sensitive to low thermal levels, so that the annular passage taken by air bubbles and / or heated fuel (due to the direct vicinity of the engine) constitutes a real thermal protection sleeve. for the central passage which is used by the supply fuel.
• FIG. 2b a variant of this embodiment of the invention has been illustrated.
• the spacing fins 122 are now integral with the inner wall 120, and extend as previously radially along the axis X so as to ensure by their free edge 122.1 the maintenance of the inner wall 120 in the wall exterior 110.
• Such an embodiment is perhaps more delicate in terms of the manufacture of the unitary assembly constituted by the interior wall 120 and its protruding fins 122, but a non-negligible advantage is obtained in so far as these spacing fins are then made of a slightly "noble" material, in particular that used to make the interior wall 120.
• the multi-layer material constituting the outer wall 110 here comprises an additional layer of adhesive 116 between the intermediate layer 115 forming a barrier and the outer protective layer 114.
• an adhesive layer may prove to be advantageous in certain cases, for example when the materials constituting the layer 115 forming the barrier and the outer layer 114 are difficult to compati ⁇ ble.
• a material such as polyamide may be used for the inner 113 and outer 114 layers, while the material constituting the inner wall 120 may be a single-layer material of the type of materials previously indicated for the variant already described. .
• the pipe 100 is constituted by an external tubular wall 110 of axis X, inside which an internal veil transver ⁇ sal 212 is arranged: the wall 110 and the internal veil 212 thus delimit two adjoining passages 211.1, 211.2 which allow two different fuel flows to be channeled.
• This internal veil 212 thus defines another internal partitioning, which is made of single-layer material compatible with the fluid concerned.
• the internal veil 212 constitutes a partition, and this partition may or may not be diametrical.
• the internal veil 212 is arranged at a non-zero distance, denoted d, from the axis X of the external wall 110.
• Such a particular embodiment will be very suitable especially in the case where the fluid is a diesel fuel: indeed, the passage 211.1 of larger section will then be used for the supply diesel, and the passage 211.2 of smaller section for the return of excess diesel to the tank, the distance d then being determined in such a way that these passages have respectively the same section as the two pipes (of the mono-tube type with circular section) usually used for the supply and return of diesel.
• a 10.5 mm pipe can be chosen of internal diameter, and an internal veil positioned at a distance d of 1.5 mm from the X axis.
• the outer wall 110 is again made of a multi-layer material, with an inner layer 113 of low permeability to the fluid concerned and an outer protective layer (possibly with between them a layer of adhesive).
• an outer protective layer possibly with between them a layer of adhesive.
• the additional barrier layer 115 Figures 2c and 2d
• the adhesive layer 116 Figure 2d
• This single-layer internal veil is then advantageously made of polyamide.
• the passages 211.1 and 211.2 are both borrowed by the same fluid, so that one is, as before, free from any constraint of permeability for the corresponding internal veil 212.
• the absence of rigid constraints for the realization of the internal veil 212 also makes it possible to provide a wall of small thickness, that is to say of thickness appreciably smaller than that of the external wall 110 which is as for it made of a multi-layer material.
• a thickness close to 0.8 mm may be used for the internal wall 212, while the outer wall 110 will in practice have a thickness close to 1 mm.
• an internal diameter close to 10 mm a pipe is obtained which provides the same flow possibilities as a conventional two-piece assembly.
• the intermediate web 212 forming a partition between the passages 211.1 and 211.2 allows a heat exchange for the fluid: the passage 211.2 used here by the heated air bubbles and / or fuel (after their passage through the in the vicinity of the engine) in fact makes it possible to heat the fuel for feed, which is advantageous if fuels sensitive to low thermal levels are used (diesel oils in particular).
• the pipe 100 is constituted by an outer tubular wall 110 of axis X, inside which are arranged three internal webs 312 extending radially from the axis X, of this wall outside.
• the outer wall 110 and the three sails 312 thus delimit three contiguous passages 311.1, 311.2 and 311.3, which make it possible to channel two different flows of fluid: two passages (in this case passages 311.1, 311.2) are used to channel a first flow, while the third passage (here passage 311.3) makes it possible to channel a second flow.
• These three radial webs 312 thus define another internal partitioning, which is made of single-layer material compatible with the fluid concerned.
• the three webs 312 here constitute radial partition walls which meet at the level of the axis X of the outer wall 110, and these partitions can be arranged so as to define three dihedral angles predeter ⁇ mined.
• the sails 312 are arranged so as to define three dihedrons whose angles a, b, and ç_ are respectively 116 °, 116 ° and 128 °.
• Such a particular embodiment will be suitable especially in the case where the fuel is in diesel fuel: in fact, we will then use the two passages 311.1, 311.2 of smaller section (ancs a and b) for the supply diesel, and the passage 311.3 of larger section (angle ç_) for the return of the excess diesel to the tank, so as to obtain passages of the same sections as the two pipes (of the mono-tube type with circular section) usually used for the supply and return of diesel.
• the pipe according to the invention is intended to replace the assembly constituted by a single-pipe pipe of 8 mm inside diameter (for diesel fuel supply) and a single-pipe pipe of 6 mm inside diameter (for the return of excess diesel), one can choose a pipe of 10.8 mm inside diameter, with radial sails whose thickness is close to 0.8 mm.
• the outer wall 110 is again made of a multi-layer material, with an inner layer 113 of low permeability to the fluid concerned and an outer protective layer (possibly with between them a layer of adhesive).
• an outer protective layer possibly with between them a layer of adhesive.
• the radial webs 312 may be integral with the inner layer 113 of the outer wall 110, this solidarity advantageously resulting from the same coextrusion of the corresponding profile.
• These single-layer internal webs are then advantageously made of polyamide.
• the passages 311.1, 311.2 and 311.3 are all borrowed by the same fluid, so that one is in fact free from any constraint of permeability for the corresponding internal sails 312.
• the absence of rigid constraints for the realization of the internal webs 312 also makes it possible to provide walls of small thickness, that is to say of appreciable thickness- ment weaker than that of the outer wall 110 which is in turn made of a multi-layer material.
• a thickness close to 0.8 mm may be used for the radial sails 312, while the outer wall 110 will in practice have a thickness close to 1 mm.
• the two internal sails 312 delimiting the passages 311.1 and 311.2 on the one hand, and the passage 311.3 on the other hand allow a heat exchange for the fuel: the passage 311.3 taken by the heated air bubbles and / or fuel (after their passage in the vicinity of the engine) makes it possible in fact to heat the supply fuel arriving by the passages 311.1 and 311.2, which is interesting if you use fuels sensitive to low thermal levels (diesel in particular).
• FIG. 3 thus differs from that of FIG. 1 by the presence of a channeling section 32 provided for the recovery of fuel vapors from the tank (there is the non-return valve 27 and the vent pipes 28).
• the pipe 100 is now connected to the three sections 14, 15, 32 by its connector 101, and the three sections 16, 17, 26 start from the connector 102, the section 16 serving as before to supply the engine with fuel, the section 17 on return of excess fuel, and the section 26 serving as previously to channel the fuel vapors emanating from the tank to the recuperator 22 via the non-return valve 24.
• the installation is identical to the previous one.
• the fuel vapors coming from the tank 10 are therefore directed by the section 32 towards the connector 101, to also penetrate this line 100, to exit therefrom via the connector 102 then through the section 26, and finally be directed towards the steam recovery unit 22.
• the pipe 100 is constituted by an outer tubular wall 110 inside which are arranged three sails 412 extending radially from the axis X of this outer wall.
• the sails 412 and the wall 110 thus delimit three contiguous passages 411.1, 411.2 and 411.3, which make it possible to channel different flows of fluids, for example two different flows of liquid fuel and a flow of fuel vapors: passage 411.1 can be used to channel the supply fuel, passage 411.2 for the return of excess fuel to the tank, and passage 411.3 for the recovery of fuel vapors from the tank.
• These sails 412 thus define another interior partitioning, which is made of single-layer material compatible with the fluid concerned.
• the three sails 412 meet at the level of the axis X of the outer wall, but it is possible in a variant to make the sails start from a wider, full or hollow central core. Furthermore, these three sails 412 here define three dihedrons of the same angle (that is to say 120 °), so that the three contiguous passages 411.1, 411.2, 411.3 are then of the same section. It goes without saying that we can provide a different angular arrangement for these three sails. However, the regular distribution illustrated here has the advantage of imparting mechanical resistance to crushing and a bendability which do not depend on the arrangement of the pipe.
• the outer wall 110 is again made of a multi-layer material, with an inner layer 113 to low permeability to the fluid concerned and an outer layer 114 intended to provide mechanical protection and possibly also chemical (with possibly between them an adhesive layer).
• an intermediate layer 115 forming a barrier with respect to at least one of the components of this fluid (FIGS. 4a and 4b) and a layer d adhesive 116 (FIG. 4b), with the same functions and advantages as those mentioned above.
• the radial webs 412 are unitary integral with the inner layer 113 of the outer wall 110, this solidarity resulting for example from the same coextrusion of the corresponding profile.
• the intermediate web 412 forming a partition between the passages 411.1 and 411.2 authorizes a heat exchange for the fluid: the passage 411.2 used here by the heated air bubbles and / or fuel (after their passage through the in the vicinity of the engine) in fact makes it possible to heat the fuel for supply.
• the pipe 100 is constituted by two tubular walls 110 and 520, which are essentially coaxial and held at a distance from one another by spacing fins 512 (FIG. 4c) or 522 (FIG. 4d), here three in number.
• the two tubular walls 110 and 120 are here of circular section, and the inner wall 520 has a transverse internal veil 521, which in this case is a diametral veil passing through the axis X, so that this internal wall has two adjoining passages 523, 524 whose sections are identical here, and the outer wall 110 defines with this inner wall 520 an annular passage 511.
• the three passages 523, 524, 511 thus delimited allow to channel different flows of fluids, for example here two different flows of liquid fuel and a flow of fuel vapors from the tank, vapors which can thus be recovered.
• the spacing fins 512 are integral with the outer wall 110, and extend radially along the axis X so as to ensure, by their free edge 512.1, the maintenance of the inner wall 520.
• the inner wall 520 is therefore separated from the outer wall 110, which is interesting when it comes to bending the pipeline.
• the free edge 512.1 of the fins 512 may be rectilinear, or alternatively have undulations which constitute communication openings between the adjacent annular chambers (here three in number) defined by these fins and constituting the annular passage 511, which then allows to balance the pressures between these chambers.
• the spacing fins • 522 are integral with the interior wall 520, these fins extending, as previously, radially along the axis X so as to ensure by their respective free edges 522.1 the maintenance of this wall interior.
• Such an embodiment is perhaps more delicate from the manufacturing point of view, but a non-negligible advantage is obtained insofar as all of these spacing fins can then be made of a material that is not very "noble", in particular that used to make the inner wall 520 and the inner veil 521 thereof.
• spacing fins must more generally be understood in a broad sense within the framework of the invention: in particular, provision may be made, instead of ribs extending parallel to the X axis illustrated here, for support means axially interrupted, for example in the form of protruding pins or also rings, arranged at predetermined intervals (possibly chosen according to the particular bending of the pipe).
• the outer wall 110 is again made of a multi-layer material, with an inner layer 113 of low permeability to the fluid concerned and an outer layer 114 intended to provide mechanical and possibly also chemical protection (with possibly a layer of adhesive).
• an intermediate layer 115 forming a barrier with regard to at least one of the components of this fluid (FIGS. 4c and 4d), and a layer of adhesive 116 (FIG. 4d), with the same functions and advantages as before.
• the outer wall 110 thanks to its multi-layer structure, thus ensures for the line 100 both the low permeability with respect to the fuel, and the mechanical and chemical resistance to external aggressions.
• the intermediate barrier layer 115 is protected by the adjacent layers, both against attack by. the fuel vapors (by the layer 113) and by the liquid fuel (by the layer 113 and by the intermediate wall 520), only against external aggressions, of mechanical and chemical type (by the layer 114).
• the spacing fins 512 may be integral with the inner layer 113 of the outer wall 110, this solidarity advantageously resulting from the same coextrusion of the corresponding profile.
• These fins 512 will then be made of polyamide.
• the inner wall 520 has the sole function of constituting a partition, delimiting by its internal web 521 the two adjoining passages 523, 524. These two passages 523, 524 are preferably assigned to the supply and return of the fuel liquid: the said passages are therefore both taken by the same fluid, on either side of the internal veil 521, so that it has been possible to completely overcome any permeability constraint for the internal wall 520 of the pipe 100.
• the inner wall 520 is also completely protected by the above-mentioned outer wall 110, so that practically any significant constraint is overcome. of mechanical resistance. Therefore, it is possible to use less "noble" materials to make the inner wall 520 and the inner veil 521 thereof. It will in particular be possible to use a single-layer material such as polyamide, high density polyethylene, polypropylene, or even a recycled material from the aforementioned materials.
• passages 511, 523 and 524 for the two flows of liquid fuel and the flow of fuel vapors, it may in certain cases prove to be advantageous to prefer a passage rather than the other. This is for example in the case where the line 100 is used to connect the fuel tank of a vehicle to the engine of said vehicle, using one of the adjoining passages (for example passage 523) to channel the fuel supply, and the other adjacent passage (passage 524) for the return of excess fuel to the tank, thereby reserving the annular passage 511 for the fuel vapors coming from the tank.
• the line 100 is used to connect the fuel tank of a vehicle to the engine of said vehicle, using one of the adjoining passages (for example passage 523) to channel the fuel supply, and the other adjacent passage (passage 524) for the return of excess fuel to the tank, thereby reserving the annular passage 511 for the fuel vapors coming from the tank.
• the passage 524 taken by air bubbles and / or heated fuel provides a thermal protection effect for the passage which is used by the fuel feed, which passage is further maintained at a distance from the outer wall 110 thanks to the spacing fins 512.
• an accidental cut of the outer wall 110 does not risk causing a leak of liquid fuel, since the inner wall 520 forms a separate partition confining the liquid.
• this will in practice be determined as a function of the desired passage sections. So for example, if you wish to have the same passage sections as with three independent pipes of 6 mm internal diameter, it will suffice to choose an internal wall of 9 mm internal diameter and an external wall of 12.3 mm inner diameter (the inner wall then having a thickness of 0.8 mm).
• the pipe 100 is constituted by an outer tubular wall 110 inside which are arranged two internal walls 620, 630 distant from each other.
• the internal walls 620, 630 delimit, with the external wall 110, two lateral passages 621, 631, as well as a central passage 611, the three passages thus defined making it possible to channel different flows of fluids, for example two different flows of fuel liquid as well as a flow of fuel vapors expected to be recovered.
• These two internal walls 620, 630 thus define another internal partitioning, which is made of single-layer material compatible with the fluid concerned.
• the two internal walls can be arranged in multiple ways, as soon as the three contiguous passages are delimited and individually have the desired section. It is thus possible to provide that these internal walls are in the form of webs connecting substantially perpendicular to the external wall at their end edges.
• the outer wall which is here again made of multi-layer material, has the same thickness over its entire periphery.
• each internal wall 620, 630 is directly connected to a partial internal layer respectively 113, 623 of the external wall 110, so as to form a continuous wall which here has a section of substantially circular shape, the residual parts of this external wall, referenced 625 and 635, then forming two connecting fabrics which are also made of multi-layer material.
• FIGS. 4e and 4f there are two circular walls, the interior space of which forms each lateral passage 621, 631, these two walls being enveloped laterally (on their half-circumference facing outwards) by the other layers forming the outer wall 110, and being connected by the two connecting fabrics 625, 635 with which they delimit the central passage 611.
• Such an embodiment is not only advantageous for manufacturing, since the pipe can be produced directly by coextrusion, with a perfect seal for the lateral passages 621, 631 since there is no connection (by heat welding or the like ) likely to be a weakness in the event of wear for the desired seal, but also for making the end fittings (fittings 101 and 102 in FIG. 1).
• two connecting fabrics 625, 635 will be chosen whose width, denoted L, is determined in such a way that the section of the central passage 611 corresponds to that of a single-tube pipe of circular section usually used to recover the fuel vapors.
• this value D will be chosen for the two walls defining the lateral passages 621, 631 / and an L value close to 1.6 D for the central passage 611.
• the outer wall 110 is again made of a multi-layer material, with an inner layer 113 with low permeability to the fluid concerned and an outer layer 114 intended to provide mechanical protection and possibly also chemical (with possibly between these a layer of adhesive).
• an intermediate layer 115 (FIGS. 4e and 4f) forming a barrier with respect to at least one of the components of this fluid, and a layer of adhesive 116 (FIG. 4f), with the same functions and advantages as before.
• the external wall 110 thanks to its multi-layer structure, again makes it possible to ensure, for the pipe 100, both the low permeability with regard to the fuel, and the mechanical and chemical resistance to external aggressions.
• the intermediate barrier layer 115 is protected by the adjacent layers, both against attack by fuel (by layer 113) and against external attack, of mechanical type (by layer 114).
• each internal wall 620, 630 is unitarily integral with the corresponding partial internal layer 113, 623 of the external wall 110, this solidarity resulting for example from the same coextrusion of the corresponding profile.
• These internal walls are then advantageously made of polyamide.
• the lateral passages 621, 631 are preferably taken here by the fuel (supply and return) and the central passage 611 by the vapors to be recovered.
• the absence of rigid constraints for the realization of the internal walls 620, 630 also makes it possible to provide walls of small thickness, that is to say of thickness considerably less than that of the external wall 110. could for example use an individual thickness close to 0.5 mm for each of the internal walls, while that the outer wall 110, which is here of essentially bi-circular section, will in practice have a thickness close to 1 mm.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Transportation (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)

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• 1993
  • 1993-10-28 EP EP93924647A patent/EP0619864A1/de not_active Withdrawn
  • 1993-10-28 CA CA002126246A patent/CA2126246A1/fr not_active Abandoned
  • 1993-10-28 WO PCT/FR1993/001060 patent/WO1994010491A1/fr not_active Application Discontinuation

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