EP4288684A1

EP4288684A1 - Fluid transfer component with flexible region forming bellows

Info

Publication number: EP4288684A1
Application number: EP22707480.4A
Authority: EP
Inventors: Jérémy Dreux; Marc Novellani
Original assignee: Akwel SA
Current assignee: Akwel SA
Priority date: 2021-02-04
Filing date: 2022-02-04
Publication date: 2023-12-13
Also published as: FR3119433B1; WO2022167769A1; CN116917653A; FR3119433A1; JP2024509363A

Abstract

The invention relates to a fluid transfer component (10), in particular for a fluid transfer circuit (100) of a motor vehicle, comprising a part (14) for connection with another component of the circuit, in which said part (14) comprises a tubular wall (16) delimited by internal and external faces, extending in a longitudinal direction (Y) and comprising a main section (18) extended by an end section (20) for connection with the other component, the connecting part (14) being obtained by moulding of a plastic material. According to the invention, the main section (18) comprises a flexible region forming bellows (22), axially and functionally distinct from the end section (20) having a helical groove on the inner face of the wall (16), imprinted by hollow moulding in the internal face, in order to create an internal geometry extending in the form of a spiral in the region (22) of the wall (16) allowing elastic deformation of the part (14) when exposed to a bending force.

Description

Title of the invention: Fluid transfer component with flexible bellows region.

[1]The present invention relates to a fluid transfer component. The invention applies to the field of fluid transfer, in particular the field of the interconnection between them of several fluid transfer circuits.

[2]It applies more particularly but not exclusively to the transfer of fluid in a fuel circuit, an air or vacuum circuit, a steam circuit or even a cooling circuit of an engine, a battery for a electric or hybrid vehicle, power electronics or others, for example by means of a heat exchanger.

[3] The invention relates to an improvement to the elastic connection sleeves for pipes and ducts, these sleeves being intended to absorb the expansions and contractions of the pipes by absorbing the vibrations and by cutting the resonance phenomena and possibly allowing faults in the alignment between two consecutive pipes of the circuit.

[4] In a heat exchanger in which different fluids (coolant, fuel, air) can flow, it is often desirable to maximize the number of fluid flow channels in a minimum of space in order to improve heat exchanges. It may then be necessary to connect together a plurality of channels, for example arranged parallel to each other and spaced apart by a center distance of relatively small dimension, via connecting elements designated as “connecting bridges” of very short lengths. This type of architecture can for example be used to regulate the temperature of a battery pack of an electric or hybrid vehicle.

[5] I1 is known to make such connecting elements in the form of curvilinear tubes in order to respect a predefined path for the connection to the fluidic network. These tubes are generally produced by means of an extrusion machine at the outlet of which they are presented in a rectilinear shape before being bent and hot formed. In addition, these tubes, which can be single-layer mainly in polyamide, are generally formed with thin thicknesses (typically of the order of a millimeter). Such tubes are on the other hand sometimes too rigid to absorb mechanical dispersions linked not only to the positioning of the parts to which they are intended to be connected but

SUBSTITUTE SHEET (RULE 26) also linked to their own geometric dispersions at the end of the extrusion and thermoforming processes, to the precision of their cut, etc. In addition, they undergo before assembly on the vehicle or on another member as well as during their operation, geometric variations linked to the effects of expansion/contraction in particular due to temperature variations.

[6]In addition, these tubes are shaped by various thermoforming processes (oven, internal circulation of hot air or steam, etc.) after being introduced into a shape template. When shaping the tube in the template, significant stresses will be exerted on the material, stresses which will only be partially erased by the thermoforming process. The latter will therefore continue to relax during the life of the product, and in particular its exposure to temperature fluctuations, which will generate geometric variations and additional constraints.

[7] These variations, in the event of excessive rigidity of the tube, can make their assembly difficult and/or can generate significant stresses on the connections in operation.

[8]Concerning the production of such coupling elements in the form of rubber tubes, the latter can provide flexibility allowing them to absorb variations in spacing but are particularly bulky because generally requiring a fixing collar and a thickness greater than those of thermoplastic tubes. It is therefore understandable that, for the production of short tubes with significant geometric constraints, this last solution is not suitable either.

[9] There is thus a need for fluid transfer components acting as "connecting bridges" allowing the channels of a fluid transfer network to be connected to each other. These components must tolerate in particular the geometric deformations linked to expansions/contractions under the effect of temperature fluctuations, and in particular the differential variations between the channels to be connected and the fluid transfer component itself.

[10] Known from the state of the art, patent application DE 10 2013 218711A1 which describes a cap provided with a bellows, patent application EP 2 014 446A1 which describes a method of manufacturing a pipe provided of a bellows, patent application US 2002/0062873A1 which describes a hollow plastic product for an air intake system of an internal combustion engine for use in a motor vehicle provided with a bellows, the application patent FR2987873A1 which describes an inlet connector

SUBSTITUTE SHEET (RULE 26) turbocharger comprising a bellows and finally the patent application FR2881982A1 which describes a bent pipe for the isolation of vibrations transmitted by pipes comprising bellows at each end.

[1 l] An object of the present invention is to provide a fluid transfer component for a fluid transfer circuit of a motor vehicle which has mechanical properties making it possible to absorb positioning dispersions both when the component is new and after during its life in use while offering a multiplicity of possible forms at a reasonable cost.

[12] To this end, the subject of the invention is in particular a fluid transfer component, in particular for a fluid transfer circuit of a motor vehicle, comprising a connection part with another component of the circuit, in which said part comprises a tubular wall delimited by inner and outer faces, extending in a longitudinal direction and comprises a main section extending by an end section for connection with the other component, the connecting part being obtained by molding by injection of a plastic material into a free molding cavity globally defining the general shape of the connecting part, characterized in that the main section comprises a flexible region forming a bellows, axially and functionally distinct from the end section presenting on the internal face of the wall a helical groove, printed by hollow molding in the internal face, in order to create an internal geometry extending t in the shape of a spiral in the bellows of the wall allowing an elastic deformation of the part under the effect of a bending force.

[13] Thanks to the invention, due to the formation of an internal spiral relief, the connecting part can absorb bending stresses facilitating the integration of the component into its environment, for example a fluid transfer network with very high dimensional constraints. The production by molding of the connecting part at least, and more generally of the entire component, makes it possible to control with great finesse the thickness of the wall in the flexible region. This control makes it possible to guarantee a minimum thickness of the wall along the groove and thus limit the zones of fragility likely to break under the effect of the bending stresses. Advantageously, the helical groove is configured to allow the removal, for example, of a molding core from a molding die forming the internal cavity of the connecting part, by a simple helical unscrewing movement along this groove. . In general, the free molding cavity is configured to give the general shape to the connecting part.

SUBSTITUTE SHEET (RULE 26) [14] A fluid transfer component according to the invention may further comprise one or more of the following characteristics.

[15] In a preferred embodiment of the invention, said connecting part defining an internal fluid flow channel, this internal channel is dimensioned so that its internal cross section defined between the flexible region and a free end of the section end is greater than a nominal thread diameter of a threaded object which can cooperate in a complementary manner with the groove, in order to allow said object to be withdrawn from the connecting part by unscrewing along the groove.

[16] In a preferred embodiment of the invention, the flexible region has on the external face of the wall a helical thread crest, imprinted by molding on the external face of the wall, the helical crest and groove are configured to engage by form complementarity one in the other in order to form, in the flexible region of the wall, a continuous external bulge winding according to a geometry of the spiral type around the longitudinal direction of the connecting part.

[17] In a preferred embodiment of the invention, in the flexible region, the connecting part comprises a corrugation relief molded on the external face of the wall, for example formed by a plurality of adjacent circumferential rings or by a continuous helical relief.

[18] In a preferred embodiment of the invention, the wall thickness is substantially constant in the flexible region.

[19] In a preferred embodiment of the invention, the plastic material is a thermoplastic material is chosen from PA612, PA12, PAU, a polyolefin (PE, PP), an elastomeric thermoplastic (PP/EPDM, SEBS , NBR/PVC, TPU) or rubber (EPDM, FKM, Silicone) or a combination of one of the components.

[20] In a preferred embodiment of the invention, the component is a manifold-distributor of a fluid to an external fluid network comprising a main fluid distribution column provided along a longitudinal axis with a plurality of orifices opening into a plurality of corresponding conduits, each of the conduits being formed by said connecting part.

[21] In a preferred embodiment of the invention, the component is a tubular article of generally bent shape, comprising two substantially straight connecting parts connected to each other by a bent portion.

[22] In a preferred embodiment of the invention, wherein the wall thickness is substantially constant in the flexible region and is chosen thinner than the thickness of the

SUBSTITUTE SHEET (RULE 26) the wall of the end section. Indeed, in the end section, it is necessary to guarantee a tightness of the connection with the other component which risks, due to its connection function, being mechanically stressed by the other component in deformation and therefore of be more sensitive to the risk of its wall bursting. On the other hand, in the main section comprising the bellows, the wall thickness can be reduced, which makes it possible to guarantee relatively great flexibility in the region of the bellows.

[23] In a preferred embodiment of the invention, the connecting end section is in the form of an elongated cylindrical tube extending longitudinally in the main direction of the connecting part and defining, on the surface internal and/or on the external surface of the tube, a sealing surface for its fluid-tight connection with the other component. Optionally, the internal or external sealing surface can be slightly tapered.

[24] In a preferred embodiment of the invention, said end section comprises connection means made in the form of a quick-coupling means, for example by snap-fitting, by tight fitting or by screwing, in particular formed directly by injection molding with the connecting part.

[25]For example, this quick-coupling means is obtained directly during the molding of the bellows.

[26] In a preferred embodiment of the invention, the connecting means are made in the form of threads obtained on the outer surface or tapping on the inner surface of the wall.

[27] In one embodiment of the invention, the component comprises an accessory or a relief configured to perform a function chosen from: a heat dissipation function, a sealing function, a connection function, a rigidity function .

[28]Other characteristics and advantages of the invention will appear in the light of the following description, made with reference to the appended drawings in which:

[29] [Fig 1]: Figure 1 shows a schematic perspective view of a ramp for collecting or distributing fluid forming a fluid transfer component according to a first embodiment of the invention, connected to other components of a fluid transfer circuit;

[30] [Fig 2]: Figure 2 shows a schematic perspective and cutaway view of the ramp of Figure 1;

SUBSTITUTE SHEET (RULE 26) [31] [Fig 3]: Figure 3 shows a schematic perspective view of the ramp of Figure 1;

[32] [Fig 4]: Figure 4 shows a schematic view in perspective and in section of the ramp of Figure 3;

[33] [Fig 5]: Figure 5 shows a schematic view in perspective and in section on an enlarged scale of a connecting part of the ramp of Figure 4;

[34] [Fig 6]: Figure 6 shows a detailed schematic view on an enlarged scale of a flexible region of the component according to the first embodiment;

[35] [Fig 7]: Figure 7 shows a schematic perspective view of a tubular component according to a second embodiment of the invention;

[36] [Fig 8]: Figure 8 shows a schematic perspective view of a fluid transfer component according to a third embodiment, connected to other components of a fluid transfer network;

[37][Fig 9]: FIG. 9 represents a schematic and perspective view of a first fluid transfer component of the prior art and of the fluid transfer component according to the third embodiment of the invention.

[38] [Fig 10]: figure 10 represents a comparative graph of two curves of evolution of a value of the bending force as a function of an axial displacement of the components of the prior art and of the invention illustrated in Figure 8.

[39] A first embodiment of a fluid transfer component for a motor vehicle according to the invention is shown schematically in Figures 1 to 6. This fluid transfer component bears the general reference 10.

[40] There is shown schematically in this same figure 1 a fluidic network or fluid transfer circuit for a motor vehicle comprising at least the fluid transfer component 10 according to the invention. The fluidic network is designated by the general reference 100. This circuit 100 comprises in this example other fluid transfer components 110 and 120 illustrated in the figures and which will be described in more detail below.

[41] In this first embodiment illustrated in Figures 1 to 6, in order to allow for example the connection of this fluidic network 100 to a main pipe for collecting or distributing the fluid, the component 10 forms a collecting ramp and/ or fluid dispenser. This ramp 10 comprises, as illustrated in Figures 3 and 4, a column 12 provided along a longitudinal axis with a plurality of fluid flow orifices 11 spaced from each other.

SUBSTITUTE SHEET (RULE 26) [42] In known manner, a manifold distributing or collecting a fluid allows the distribution or collection to or from a fluid circulation network, for example a thermal regulation circuit of a battery pack or an electric and/or hybrid motor vehicle battery (not shown in these figures).

[43]Generally, thermal regulation is ensured by means of a heat transfer fluid which circulates in a heat exchanger positioned in contact with the battery and through which the heat transfer fluid passes along a more or less complex fluid circulation path.

[44]The thermal regulation of such a battery pack is generally achieved by a multiplicity of tubular fluid circulation channels arranged in series or in parallel along an exchange surface to form an effective heat exchange zone. This fluidic network, for example, forms a tight grid over the entire surface of the battery to form an effective heat exchange zone.

[45]This network has, for example, a row of pipe ends extending longitudinally forming as many network inlet/outlet orifices for fluid circulation. The distance between the ends of the pipes can on the one hand be relatively small and on the other hand can present a variability of tolerances.

[46] In accordance with the invention, the fluid transfer component 10 comprises a connection part 14 to another component 110, for example one of the components 110 or 120 of the circuit 100. In this first embodiment, the component 10 forms a ramp which comprises a plurality of parts 14 for connection to a plurality of components 110 of the fluidic network 100.

[47] Thus, as can be seen in Figure 3, the ramp 10 preferably comprises a main fluid distribution column 12 extending longitudinally along the X axis and the plurality of connecting parts 14 form transfer pipes fluid extending parallel for example with respect to each other and extending transversely, in the example described, in a direction Y at regular intervals along the column 12. Of course, in a variation not illustrated on the figures, the fluid transfer pipes may have other orientations than perpendicular orientations with respect to the longitudinal direction of the column 12.

[48] More particularly and as illustrated in detail in Figure 5, the connecting part 14 comprises a peripheral tubular wall 16 extending in the longitudinal direction Y. The connecting part 14 delimits a main section 18 which is extended by a end section 20 for connection with another component 110 of circuit 100.

SUBSTITUTE SHEET (RULE 26) [49] Preferably, the connection section 20 comprises connection means made in the form of a quick-coupling means, for example by snap-fitting, by tight fitting or by screwing.

[50]As illustrated in detail in Figure 2, the component 110 comprises for example an end fitting 112 of the fir tree notch type. The component 110 is in this example connected to the corresponding connecting part 14 of the ramp 10 by fitting the fir tree notch fitting 112 inside the end section 20 of connection. Of course, the invention is not limited to the shape of the means for connecting the end section 20.

[51]In addition, in a variant not shown, other connection means can be envisaged, such as connection means made in the form of threads obtained on the external surface or tapping on the internal surface of the wall.

[52] More generally, the connecting end section 20 is in the form of an elongated cylindrical tube extending longitudinally in the main direction Y of the connecting part 14 and defining the internal surface or the surface a sealing surface for its fluid-tight connection with the other component. The connecting part 14 also preferably comprises an outer annular shoulder delimiting the end section 20 of the main section 18. As illustrated, this annular shoulder forms the base of a widening of the connecting part 14 in the direction of its free end. 20 A.

[53] In this first embodiment, this connecting part 14, and preferably the entire ramp 10, is molded by injection into a free molding cavity of a molding die, of a plastic , for example a relatively rigid thermoplastic material.

[54] In particular, in accordance with the invention, the main section 18 comprises a flexible localized portion 22, axially and functionally distinct from the connecting section 20. This flexible localized portion 22, hereinafter referred to as bellows 22, presents on one side internal 161 of the wall 16 a helical groove 26, printed by hollow molding in the internal face 161, in order to create an internal relief in spiral in the region 22 of the wall 16. This conformation of internal relief in spiral allows an elastic deformation in bending of part 14 at the level of bellows 22.

[55] Preferably, said connecting part 14 delimiting an internal fluid flow channel 15, this internal channel 15 is dimensioned so that its internal cross-section defined between the bellows region 22 and a free end 20A of the end 20

SUBSTITUTE SHEET (RULE 26) is greater than a nominal threading diameter of a threaded object which can cooperate in a complementary manner with the helical groove 26, in order to allow said object to be withdrawn from the connecting part 14 by unscrewing along the helical groove. Preferably, this object is a molding core which must be removed after a component molding operation.

[56] Furthermore, in order to further minimize the stresses of the bending forces in the bellows 22, the wall 16 also has a non-rectilinear external relief on the external face 16E of the wall 16.

[57] Preferably, the bellows 22 also has on the outer face 16E of the wall 16 a helical crest 28 of threading, printed by molding on the outer face 16E of the wall 16. In this case, the inner helical groove 26 and the outer helical crest 28 are configured to form-fit one another to together form in the bellows 22 of the wall 16 a single bulge wrapping in a spiral-like geometry around the direction longitudinal Y of the connecting part 14.

[58] This geometry of the wall 16 has in particular a longitudinal profile formed of undulations delimiting turns of the spiral. Thus, as can be seen in FIG. 6, the wall 16 presents in the bellows 22 along a longitudinal profile of the Y direction, a series of undulations which are manifested by alternate bulges and depressions of the wall 16 along the direction in which the connecting part 14 extends. Preferably, the thickness E of the wall 16 in this bellows region 22 is substantially uniform.

[59] The spiral geometry of the flexible region has been shown in more detail in FIG. 6. In this FIG. connection 14 respectively an inner wall corrugation 16 and an outer wall corrugation 16. It can be seen in particular that the two inner and outer corrugations are "in phase" and have corrugation peaks and troughs which substantially coincide axially so as to produce a wall 16 with a corrugated profile. Indeed, preferably, the corrugation of the outer face 16E tends to engage by form complementarity in the corrugation of the inner face 161, the peaks of the corrugation of one of the faces being housed in the hollows of the undulation of the other of the faces. This complementarity of the inner and outer corrugations makes it possible to define a thickness

SUBSTITUTE SHEET (RULE 26) substantially constant along the wall 16, including in the region forming the bellows 22.

[60] Furthermore, preferably, the thickness E of the wall 16 is substantially constant in the bellows region 22 along the corrugation of the wall 16 as shown in Figure 6. However, thanks to the invention, it is possible to provide a variation in the thickness of the wall 16 along the bellows-forming region 22 that is controlled and optimized in order to obtain additional effects in terms of flexibility and resistance to bursting. For example, it is possible to provide a greater wall thickness at the crests and troughs of the corrugations and a relatively smaller thickness at the level of the flanks (junction of the crests and troughs) of these corrugations.

[61] The realization of the connecting part 14 by injection molding, in general, indeed offers many possibilities. For example, in the case where the bending capacity of the connecting part 14 is only desired in a single preferred orientation of deformation, it will be possible to provide a particular conformation of the region 22 forming the bellows in terms of thickness of the wall and external geometry. Indeed, in the case of a functionally privileged orientation of bending, the region of the bellows 22 will tend to work in extension outside the bending and in compression inside the bending. Thanks, for example, to optimization by digital simulation of the thickness and the external geometry of the wall 16 of the connecting part 14, it will be possible to improve the overall bending performance of the component, taking into account its final destination. . It will however be noted that the modification of the internal geometry of the connecting part 22 is on the other hand more limited and constrained in particular by the need to remove the molding core by unscrewing.

[62] In addition, in an embodiment of the invention not shown, controlling the variation in the thickness of the wall can also make it possible to add to the connecting part 14 a function of localized rigidity in certain zones. of the component, including in the region 22 of the bellows. For example, this rigidity function can be achieved by means of ribs formed in external relief of the wall, making it possible to stiffen the connecting part 14 in certain directions while allowing its deformation in other directions.

[63] The bellows 22 of the connecting part 14 thus comprises an external corrugation relief 24 molded on the external face 16E of the wall 16. In this embodiment, the corrugation relief 24 is formed by the helical crest continue 28.

SUBSTITUTE SHEET (RULE 26) [64] However, in a variation not shown, the corrugation relief 24 may include a plurality of adjacent circumferential grooves or corrugations formed therein. Preferably, these corrugations are closed but may take the form of open rings formed in relief on the connecting part 14.

[65] From a dimensional point of view, in this example described, the thickness of the wall 16 at the level of the end section 20 is preferably greater than or equal to one millimeter in order to guarantee a connecting connection with another component 110 of circuit 100 sufficiently robust. The minimum thickness at the level of the spiral region 22, therefore at the level of the region most contributing to flexibility, preferably depends on the overall dimension of the component 10.

[66]Thus, for example, for components having a connection part of nominal diameter (vertex to vertex at the level of the bellows region 22) outside less than or equal to twelve millimeters, the thickness of the wall 16 in the bellows region 22 may be half a millimeter. For components having a connecting part with a nominal outer diameter greater than twenty millimeters, this wall thickness 16 in the flexible region 22 may be greater than one millimeter.

[67] The thickness of the wall in the bellows region 22 is thus generally chosen to be thinner than that of the wall of the end section 20 in order to have more flexibility and therefore to be able to absorb more positioning dispersion.

[68]Preferably, in order to obtain maximum flexibility in bending, it is desirable to provide a helical pitch of the inner and outer winding along the longitudinal axis making it possible to obtain a relatively tight corrugation, i.e. that is, by forming an alternation of peaks and troughs close to each other. This prevents the material of the connecting part 14 from working in elongation and compression and thus limits the stresses in the bellows region 22.

[69] In the example, the number of turns necessary to obtain the desired flexibility depends on several parameters, and in particular on the external diameter of the connecting part 14. Of course, it is desirable to increase the number of turns of the flexible region with the diameter. Thus, preferably, the minimum number of turns per connection part 14 can be defined by the following ratio: of the outer diameter (in millimeters) over the number three.

[70] For a connecting part with a nominal outer diameter less than or equal to ten millimeters, a minimum number of three turns per connecting part 14 is desirable

SUBSTITUTE SHEET (RULE 26) to get an effect. It may thus be desirable to double the number of turns for a tube with an outside diameter of twenty millimeters.

[71] In another preferred embodiment of the invention, the tubular article comprises a middle portion which extends adjacent to the end portion, wherein the thickness of the middle portion is between 0 .2 millimeter and 2 millimeters.

[72] There is shown in Figure 7, a fluid transfer component 10 according to a second embodiment. This fluid transfer component 10 is in the form of a tubular joint 50.

[73] The tubular article 50 comprises a body of generally hollow tubular shape and provided with two free ends 52. In the example illustrated in FIG. 7, the tubular article 50 comprises two connecting parts 14 in accordance with the invention and interconnected by an intermediate angled portion 54.

[74] According to the invention, and as illustrated in Figure 7, each connecting part 14 comprises a peripheral tubular wall 16 extending in the longitudinal direction. The connecting part 14 delimits a main section 18 which is extended by an end section 20 connecting with another component (not shown) of the circuit 100.

[75] In accordance with the invention, the main section 18 comprises a flexible localized portion 22, axially and functionally distinct from the connecting section 20. This flexible localized portion 22 in the form of a bellows has on an internal face 161 of the wall 16 a helical groove (not visible in Figure 7), printed by hollow molding in the internal face of the tubular wall 16.

[76]Preferably, the article 100 is molded in one piece by injection and made of a thermoplastic polymer material in a free cavity of a molding die (not shown).

[77]For example, the thermoplastic material has the following mechanical properties: an elongation at longitudinal rupture greater than 50% (in accordance with the DIN EN ISO 527 standard), measured on a conditioned specimen, a modulus of elasticity less than or equal to 500 MPa (in accordance with DIN EN ISO 527), measured on a conditioned specimen. Preferably, the thermoplastic material is chosen from PA612, PA12, PAU, polyolefin (PE, PP), an elastomeric thermoplastic (PP/EPDM, SEBS, NBR/PVC, TPU) or rubber (EMPDM, FKM , Silicone) or a mixture of these components.

[78]The international standard ISO 527 is used to determine the tensile properties of plastic films and sheets on a test specimen made of plastic material

SUBSTITUTE SHEET (RULE 26) measuring less than a millimeter in thickness. Tensile properties include tensile strength, yield strength, elongation at yield point, elongation at break and in some cases Young's modulus.

[79]For example, to measure the longitudinal elongation at break, a tensile speed of 50 millimeters per minute is applied to the conditioned specimen.

[80]For example, to measure the transverse elongation at break, an elongation rate of 25 millimeters per minute is applied to the conditioned specimen.

[81]Example 1.

[82] The tubular article 50 is produced by injection molding of a thermoplastic material composed of a polyamide known under the product nomenclature according to the ISO 1874 standard: PA612-HIP, E, 22-005. This material, known under the trade name Grilamid®, has the following mechanical properties: modulus of elasticity (in English “tensile modulus”), dry (in English “dry”)/on a conditioned specimen (in English, abbreviation, “cond. ”): 550/380 MPa; Yield stress, dry/on conditioned specimen: 30/25 MPa; Elongation at break (in English “strain at break”), dry/on conditioned specimen: >50%/>50%.

[83]Example 2.

[84] The tubular article 50 is made by injection molding of a thermoplastic material composed of a polyamide known under the nomenclature of products according to the ISO 1874 standard: PA12-HIP, EHLW, 22-004. This material, known under the trade name Grilamid®, has the following mechanical properties: modulus of elasticity, dry/on conditioned specimen: 370/360 MPa; stress at yield point, dry/on conditioned specimen: 25/25 MPa; elongation at break, dry/on conditioned specimen: >50%/>50%.

[85] The thermoplastic materials (examples 1 and 2) described above are originally intended for conventional transformation processes by extrusion and have a relatively high viscosity to allow easy transformation by extrusion. In addition, the shapes described above require the wall thicknesses to be reduced to the strict minimum, these two constraints combined require the use of a machine developing significant pressures in suitable molds (for example, temperature-regulated mold, point of special injection "hot block or sheet or multiple injection point").

[86]These materials are selected for their greater flexibility than that of the grades typically used in injection molding.

SUBSTITUTE SHEET (RULE 26) [87]Furthermore, preferably, the thermoplastic material has an elongation at transverse rupture greater than 50 (%) (According to DIN EN 53504), preferably greater than 100 (%).

[88]Preferably, the bent portion 54 has a sharp bend angle (for example less than thirty degrees), in particular with the aim of reducing the size of the pipe as much as possible, thus making it possible, for example, to connect together channels very close.

[89]Although the tubular article has been described for a fitting application on a notch-fir type fitting, a tubular article according to this second embodiment is also compatible with other embodiments of the assembly of the tubular article and an end piece not described.

[90] There is shown in Figures 8 to 10, a fluid transfer component according to a third embodiment. This fluid transfer component bears the reference VI.

[91] In Figure 8, we see that the component VI forms a tubular article provided with two connecting parts 14 according to the invention. These two connecting parts 14 are, as in the second embodiment, connected together by a bent part. It will be noted that in a non-limiting manner, this bent part has a less sharp bend angle than the bend angle of the fluid transfer component of the second embodiment.

[92] This tubular article VI is mounted in a fluid transfer network 100 and as shown in Figure 8 is connected to two components 110 of general Y shape. This component 110 of general Y shape has two branches provided at their respective free ends of a fir notch tip 112, these two branches being interconnected to a central tubular trunk.

[93] Analogously to the first and second embodiments, each connection part 14 comprises a main section 18 and an end section 20 for connection with the other component 110 of the circuit 100. This main section 18 comprises a region hose 22 forming a bellows which will not be described in detail again.

[94] In this third embodiment, maximum effect has been obtained by arranging the two flexible regions 22 forming the bellows as close as possible to the bent portion 52, and preferably almost contiguous at the level of the inner face. of the elbow wall.

[95]As illustrated in figure 8, the bent part of article VI has an underside defined by the concave interior curvilinear face of the wall of the bent part and

SUBSTITUTE SHEET (RULE 26) an upper surface defined by the convex outer curvilinear face of the wall of the bent part, and connecting the two connecting parts 14 together. The presence of the bend angle of the article Vi has in particular the aim of minimizing the size of the fluid transfer network, by making it possible, for example, to connect very close channels together. The bend angle can preferably be within a range of values between 30° and 120°.

[96] In the preferred embodiment of the invention illustrated in Figure 8, it can be seen that the flexible regions 22 forming the bellows are preferably substantially contiguous in the lower surface and disjoint in the upper surface of the bent part.

[97] Figure 9 shows in detail the component VI according to this third embodiment and another component V0 of the prior art. As can be seen, this other component V0 does not include flexible regions 22 forming a bellows shaped geometrically in a spiral as in the invention on each of these connecting parts 14.

[98] In figure 10, the comparative result of bending tests subjected to the two components VI and V0 is represented in the form of a graph. This graph represents on the abscissa axis the axial displacement of the connecting parts 14 in millimeters and on the ordinate axis a force value in Newtons.

[99]It is noted in particular that to obtain the same axial displacement (axis of the abscissas), for example of three millimeters (negative or positive), the value of the force in Newtons necessary to obtain this same displacement is lower for the component VI ( fifty to one hundred newtons) than for component V0.

[100] For example, for the range of nominal diameters of the connecting parts (mainly between eight millimeters and twenty millimeters from top to top), a displacement amplitude of between one and two millimeters appears to be effective. Of course, this example is only given as an indication because the amplitude of displacement is related to the geometry.

[101] In accordance with the invention, the connecting part 14 and preferably the fluid transfer component 10 as a whole is made by injection molding a plastic material, preferably thermoplastic, in a free molding cavity of a molding die (not shown).

[102] For the manufacture of such a component, one proceeds as follows: one manufactures the connecting part 14 by injection molding. A molding die is provided comprising a mould, for example in two parts, and a core positioned inside the mold in order to

SUBSTITUTE SHEET (RULE 26) delimit at least one free molding cavity inside which a plastic material can be injected in the molten state. This free molding cavity is configured to shape the connecting part provided with the region having the shape of the bellows 22 of the invention.

[103]The mold is then closed and a plastic material is injected into the mold in the molten state. This plastic material fills the free cavity of the mould. Throughout the manufacturing step, in particular during the step of injection into the mold of plastic material, the interior volume of the connecting part 14 is filled by the core. Once the injection step is complete, the core is removed by unscrewing thanks to the helical groove printed hollow inside the connecting part and the mold is opened to extract the molded connecting part.

[104] We will now describe the main operating aspects of a tubular component according to the invention, for example according to the first embodiment.

[105] The fluid transfer component 10 obtained by the molding method described above is, in the first embodiment, a manifold/fluid distributor. This ramp 10 has a plurality of tubular conduits and must for example be integrated into a fluid distribution network that may impose dimensional geometric constraints. In this example, the fluid distribution network to which the components of the invention are connected itself includes positioning tolerances that the connecting parts 14 will make it possible to catch up with, with a minimum of effort and by exerting a minimum of residual stresses. In this context, it is important to properly control the nominal geometry of the component according to the invention, which the component of the invention obtained by molding process makes it possible to achieve better than, for example, components with more conventional geometries resulting from processes extrusion, which will incorporate more dispersions, for example related to cutting, thermoforming, etc. Indeed, the geometric dispersions of corrugated tubes obtained by the extrusion process combine with the geometric dispersions of the distribution network, and therefore risk increasing the movements/forces necessary to be carried out. Thus, the invention will facilitate the connection by limiting the efforts both by its geometric precision and by its ability to deform.

[106]As each tubular pipe is formed by a connecting part 14 according to the invention, the latter, thanks to its flexible region 22 forming a bellows, can absorb this structural rigidity of the distribution network and make it easier to

SUBSTITUTE SHEET (RULE 26) connection of the components to each other without leading to the formation of stress concentration zones that could lead to structural weaknesses. Furthermore, the manufacture by molding of this connecting part 14 has the advantage of controlling with relatively great finesse the thickness of the wall 16 in this region 22.

[107]This has a double advantage. On the one hand, the control and mastery of the thickness of the wall makes it possible to obtain a flexible region forming a bellows with properties of deformation in bending optimized since the fact of minimizing the thickness naturally plays a very important role in the obtaining high-performance deformation properties. On the other hand, the control and mastery of the thickness of the wall makes it possible to guarantee a minimum thickness of the wall preserving the robustness of this flexible region and limiting zones of fragility linked to a potential defect of localized thickness.

[108]Of course, although not illustrated in the figures, the component can be provided with other fixing means: circular or oblong hole, dovetail, clip, various forms of wedging allowing the part to be held in place final environment and which can also be used for indexing its position, its orientation, various markings which can be made directly in the injection mould, or on forms arranged on the part, via conventional marking processes: dot peen, scratching, laser, printing, pad printing, etc.

[109]Although the component has been described for a fitting application on a notch-fir type fitting, a component according to the invention is also compatible with other embodiments of the assembly of the component and of a tip, in particular by welding (rotation, laser, etc.). In this case, the injection technology retains its advantages of precise dimensional control, favorable to good quality welds.

[110] The invention also offers the possibility of forming in the fluid transfer component one or more grooves to accommodate an O-ring therein which will seal the walls of a "female" bore or another groove in which can be housed a stop clip. It can also comprise one or more clips which are configured to lock into an orifice of the female part.

[111] It is also possible to arrange at the end of this fluid transfer component according to the invention a relatively large support surface of the collar type, making it possible, for example, to provide a seal on a flat seal.

SUBSTITUTE SHEET (RULE 26) [112] The invention also offers the possibility of forming in a fluid transfer component according to the invention a stop collar in order to produce a male connection end piece, for example intended to be connected to a snap-fit connection.

[113]More generally, the component may alternatively include any accessory or additional relief configured to perform a function chosen from: a heat dissipation function, a sealing function, a connection function, a rigidity function. For example, it will be understood that the component according to the invention can comprise any part or additional internal or external reliefs, formed for example on the end section to define the connection function (for example quick coupling means) of the component to another component. These quick coupling means can be obtained for example directly during the injection molding of the connecting part 14, for example during the same molding step in the same molding cavity.

[114]The component according to the invention being defined as comprising at least one connecting part provided with a region forming a bellows. Parts or reliefs or accessories provided on the component to perform other functions of sealing, heat dissipation, rigidity, connection can be added to the component, for example by being obtained directly during the injection molding of the part of binding 14.

[115] The invention is not limited to the embodiments previously described. Other embodiments within the reach of those skilled in the art can also be envisaged without departing from the scope of the invention defined by the claims below. Thus, in particular, one would not depart from the scope of the invention by modifying the detailed shapes of the fluid transfer components, by adding additional parts or reliefs of connection function, rigidity, heat dissipation or others.

SUBSTITUTE SHEET (RULE 26)

Claims

[Claim 1] Fluid transfer component (10), in particular for a fluid transfer circuit (100) of a motor vehicle, comprising a part (14) for connection with another component (120) of the circuit (100 ), wherein said part (14) comprises a tubular wall (16) delimited by inner (161) and outer (16E) faces, extending in a longitudinal direction (Y) and comprises a main section (18) extending by a connecting end section (20) with the other component (120), the connecting part (14) being obtained by injection molding of a plastic material in a free molding cavity globally defining the general shape of the connecting part (14), characterized in that the main section (18) comprises a flexible region (22) forming a bellows, axially and functionally distinct from the end section (20) present on the internal face (161) of the wall (16) a helical groove (26), printed by molding in hollow in the internal face (161), in order to create an internal geometry extending in the form of a spiral in the bellows (22) of the wall (16) allowing an elastic deformation of the part (14) under the effect of a bending force.

[Claim 2] Component (10) according to the preceding claim, in which the said connecting part (14) delimits an internal fluid flow channel, this internal channel is dimensioned so that its internal cross-section defined between the bellows (22) and a free end (20 A) of the end section (20) is greater than a nominal thread diameter of a threaded object which can cooperate in a complementary manner with the groove, in order to allow the withdrawal of said object from the part of connection (14) by unscrewing along the groove (26).

[Claim s] Component (10) according to any one of the preceding claims, in which the connecting end section (20) is in the form of an elongated cylindrical tube extending longitudinally in the main direction (Y ) of the connecting part (14) and defining, on the inner surface and/or on the outer surface of the tube, a sealing surface for its fluid-tight connection with the other component.

SUBSTITUTE SHEET (RULE 26) [Claim 4] Component (10) according to any one of the preceding claims, in which the bellows (22) has on the external face (16E) of the wall (16) a helical crest (28) of threading, printed by molding on the outer face (161) of the wall (16), the helical crest (28) and groove (26) are configured to engage by form complementarity one in the other in order to form, in the bellows ( 22) of the wall (16), a continuous outer bulge winding in a spiral-like geometry around the longitudinal direction (Y) of the connecting part (14).

[Claim 5] Component (10) according to claim 1 or 2, in which, in the bellows (22), the connecting part (14) has a relief in undulation (24) molded on the external face (16E) of the wall (16), for example formed by a plurality of adjacent circumferential rings or by a continuous helical relief (28).

[Claim 6] A component (10) according to any preceding claim, wherein the thickness of the wall (16) is substantially constant in the flexible region (22) and is selected thinner than the thickness of the wall (16) of the end section (20).

[Claim 7] Component (10) according to any one of the preceding claims, in which the thermoplastic material is chosen from PA612, PA12, PAU, a polyolefin (PE, PP), an elastomeric thermoplastic (PP/EPDM, SEBS, NBR/PVC, TPU) or rubber (EPDM, FKM, Silicone) or a combination of one of the components.

[Claim 8] Component (10) according to any one of the preceding claims, being a manifold-distributor of a fluid to an external fluidic network comprising a main fluid distribution column (12) provided along a longitudinal axis with a plurality of orifices (11) opening into a plurality of corresponding conduits, each of the conduits being formed by said connecting part (14).

[Claim 9] Component (10) according to any one of claims 1 to 6, being a tubular article (50) of generally bent shape, comprising two substantially rectilinear connecting parts (14) interconnected by a bent portion (54 ).

[Claim 10] Component (10) according to the preceding claim, in which the two flexible regions (22) forming the bellows closest possible to the

SUBSTITUTE SHEET (RULE 26) elbow portion (54), and preferably almost contiguous at the level of the inner face of the wall of the elbow.

[Claim 11] A component (10) according to any preceding claim, wherein said end section (20) comprises connection means embodied as quick-coupling means, for example snap-fit, press fit or by screwing, in particular formed directly by injection molding with the connecting part (14).

[Claim 12] Component (10) according to the preceding claim, in which the connection means are made in the form of threads obtained on the outer surface or of threads on the inner surface of the wall (16).

[Claim 13] Component (10) according to any one of the preceding claims, comprising an accessory or a relief configured to perform a function chosen from: a heat dissipation function, a sealing function, a connection function, a of rigidity.

SUBSTITUTE SHEET (RULE 26)