Pipeline for fluid to be conveyed, system for conveying fluid and motor vehicle

Abstract

A conduit (10) for a fluid to be conveyed, in particular in a motor vehicle, comprises an inner tube (12) configured to be passed through by the fluid to be conveyed and a sheath (15). The sheath (15) includes an outer tube (14) and a plurality of tubular portions (18) defining a channel (16). Tubular portions (18) are inserted radially between the inner tube (12) and the outer tube (14), extend longitudinally along the outer tube (14), are integral with the outer tube (14), and are spaced apart from each other to form a void (17). The application also relates to a system for conveying a fluid and a motor vehicle.

Description

Technical Field

[0001] The utility model relates to a pipeline for conveying fluid, in particular to a pipeline for conveying fluid in a motor vehicle. Background Art

[0002] In particular in the automotive field, conduits for conveying fluids, for example in selective catalytic reduction (SCR) systems, are well known.

[0003] According to the prior art, such a pipe comprises an inner pipe and an outer pipe, the inner pipe being configured to be passed through by the fluid to be transported, the outer pipe surrounding the inner pipe, thereby forming a coating sheath. Such a pipe is described, for example, in document EP 2 666 985, in which the coating sheath comprises a plurality of internal grooves. In addition, in said document, the pipe is equipped with a device for heating the transported fluid, in particular a heating resistance wire applied to the inner pipe. One disadvantage is that, during the manufacture of the pipe, in particular during the thermoforming process, the walls defining the grooves will tend to collapse. In addition, since the sheath is not in close contact with the resistance wire, the resistance wire may move from its initial position and produce uneven heating conditions.

[0004] US 6116290 relates to a pipe insulation system in which circular channels adjacent to each other are present between an outer pipe and an inner pipe. A disadvantage of this system is that the excessive number of channels leads to higher production costs, especially in the variant where such channels are buried in the insulation material. Furthermore, the production process is not efficient.

[0005] CN 102588710 relates to a pipe insulation system in which circular channels adjacent to each other are present between an outer pipe and an inner pipe. A disadvantage of this system is that the excessive number of channels, the use of adhesives for connecting them and the vacuum sealing of the channels lead to higher production costs. Furthermore, the production process is not efficient.

[0006] CN 107573573 A relates to a pipe insulation system in which radial protrusions belonging to the outer pipe are present between the outer pipe and the inner pipe. A disadvantage of this system is that the radial protrusions are solid, thus allowing heat transfer. Furthermore, when the pipe is bent, there is a risk that the radial protrusions (especially when they are thin) will collapse, thus compromising the insulation.

[0007] EP 2094481 B1 relates to an insulation system for pipes for cold substances, in which circular channels spaced apart from each other are present between an outer pipe and an inner pipe. A disadvantage of this system is that such a system is not suitable for vehicles and the presence of the third pipe leads to higher production costs. In addition, the production process is not efficient. Utility Model Content

[0008] An object of the utility model is to provide a pipeline which can overcome the disadvantages of the prior art.

[0009] The pipeline is a pipeline for conveying fluid, comprising: an inner tube, the inner tube being configured to be passed through by the fluid to be conveyed, and a sheath, the sheath comprising: an outer tube, and a plurality of tubular portions defining a channel; characterized in that the tubular portions are radially inserted between the inner tube and the outer tube, extend longitudinally along the outer tube, are made integrally with the outer tube, and are spaced apart from each other to form a gap.

[0010] In particular, these features result in a pipe with improved mechanical strength which will retain its insulating properties even after having been bent.

[0011] Another advantage is that the pipe can be manufactured easily, quickly and economically while ensuring good thermal insulation.

[0012] Other characteristics and advantages of the invention will become apparent from the following detailed description, which is given by way of non-limiting example only and with particular reference to the accompanying drawings which are summarized below. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a perspective view of a pipeline manufactured according to an exemplary embodiment of the present invention.

[0014] Figure 2 yes Figure 1 Cross-sectional view of the pipe shown.

[0015] Figure 3 yes Figure 1 A perspective view of a longitudinal section of the pipe shown.

[0016] Figure 4 is a cross-sectional view of a pipe made according to an alternative embodiment of the present invention.

[0017] Figure 5 It is a cross-sectional view of a pipeline made according to another alternative embodiment of the utility model.

[0018] Figure 6 is a partial perspective view of a pipe (with the outer pipe not shown) according to a specific embodiment, wherein the tubular portions are arranged in a spiral manner.

[0019] Figure 7 yes Figure 6 A cross-sectional view of the pipe is shown, also showing the outer tube.

[0020] Figure 8 yes Figure 6 and Figure 7 A partial longitudinal cross-sectional view of the pipe shown (with the inner pipe not shown).

[0021] Fig. 9 is a partial perspective view of a pipeline according to various embodiments (with the outer tube not shown), wherein the tubular portions are arranged in a spiral manner.

[0022] Fig.10 yes Fig. 9 A cross-sectional view of the pipe is shown, also showing the outer tube.

[0023] Fig.11 yes Fig. 9 and Fig.10 A partial longitudinal cross-sectional view of the pipe shown (with the inner pipe not shown). DETAILED DESCRIPTION

[0024] With reference to the drawings, reference numeral 10 generally designates a pipeline for conveying a fluid manufactured according to an exemplary embodiment of the present invention.

[0025] For example, the pipe 10 can be used in a motor vehicle. In particular, the pipe 10 can be applied in a selective catalytic reduction (SCR) system, a battery cooling system or a water injection system.

[0026] The pipeline 10 comprises an inner tube 12, which is configured to be passed through by the fluid to be transported. In addition, the pipeline 10 comprises a sheath 15, which comprises:

[0027] - an outer tube 14, and

[0028] - A plurality of tubular portions 18 defining the passage 16. The tubular portions 18 are radially inserted between the inner tube 12 and the outer tube 14, extend longitudinally along the outer tube 14, are integrally formed with the outer tube 14, and are spaced apart from each other so as to form a gap 17.

[0029] In particular, the channel 16 has a circular cross section.

[0030] In particular, the interspace 17 is radially inserted between the inner tube 12 and the outer tube 14 .

[0031] In more detail, the gaps 17 and the channels 16 alternate in circumferential position.

[0032] The jacket 15 comprises a plurality of tubular portions 18, each defining a respective channel 16. The tubular portions 18 thus have an inner surface defining the channel 16 and an outer surface facing the inner tube 12, in particular contacting the inner tube 12. The jacket 15 and the tubular portions 18 are made in one piece, in particular by extrusion.

[0033] In particular, the cross section of the channel 16 is circular. The circular tubular portion 18 provides the advantage of reducing the contact between the inner tube 12 and the outer tube 14 and the resulting heat exchange to a minimum, while ensuring good structural strength, because such a tubular portion 18 makes it possible to bend the jacket 15 without collapsing the channel 16. Since the channel 16 will not collapse, the internal cavity will remain intact and the thermal insulation provided by the gas contained in such a cavity will still be effective. In addition, the circular shape of the tubular portion 18 minimizes the contact area between the tubular portion 18 itself and the inner tube 12 (especially in the cross-sectional view), thereby ensuring good thermal insulation. In more detail, the tubular portion 18 is in contact with the inner tube 12.

[0034] The contact area between the tubular portion 18 and the inner tube 12 can also be minimized by using a tubular portion 18 having a non-circular cross-section. For example, the tubular portion 18 can have a generally triangular outer surface, such as Figure 4 and Figure 5 As shown. This triangle defining the passage 16 has one corner or vertex that contacts the inner tube 12. According to some possible variations, the outer surface and the inner surface of the tubular portion 18 may have different cross-sections. For example, the shape of the outer surface of the tubular portion 18 may be substantially triangular, while the shape of the inner surface and the shape of the passage 16 may be circular, such as Figure 4 As shown. Figure 5 In the embodiment of the invention, on the contrary, the channel 16 also has a triangular cross section. In such a variant, the sheath 15 also provides good bending strength.

[0035] The insulating area around the inner tube 12 is also formed by the voids 17 defined by the circumferential spaces between the tubular portions 18. The spaced-apart channels 16 have the advantage of reducing the production cost and weight of the jacket 15 (since it is not necessary to form many channels 16 that are in contact with each other), while ensuring good thermal insulation due to the presence of many empty spaces (i.e., the voids 17 and channels 16).

[0036] Another advantage provided by the present invention is that it avoids the need to apply insulating foam to the outer pipe 10, which would prevent the use of clamps or other fastening devices. In addition, foam has poor wear resistance. The outer pipe of the pipe of the present invention is made of a relatively hard and strong material, has wear resistance, and can be mounted to other parts of the vehicle by suitable fastening devices.

[0037] Preferably, the channels 16 and the voids 17 contain a gas, conveniently air. The gas or air has a thermal insulation function. Air provides good thermal insulation, making the production process simple and economical.

[0038] Preferably, in the cross-sectional view, the width L of the void 17 is greater than the diameter d of the channel 16. In more detail, the width L, i.e. the distance between the outer surfaces of two adjacent tubular portions 18, is greater than the diameter d of the channel 16. The diameter d of the channel 16 is defined by the inner surface of the tubular portion 18. In other words, L>d. Therefore, it is possible to have a limited number of channels 16, thereby ensuring good thermal insulation, while having low production costs and satisfactory mechanical strength. In this example, all channels 16, all tubular portions 18 and all voids 17 have the same shape and size. In particular, the width L of the void 17 is greater than the width D of the outer surface of the tubular portion 18. In more detail, the width L, i.e. the distance between the outer surfaces of the tubular portions 18 of two adjacent channels 16, is greater than the outer diameter D defined by the outer surface of the tubular portion 18 of the channel 16. In other words, L>D.

[0039] In this example, the channels 16 are arranged substantially circumferentially around the inner tube 12. In particular, the channels 16 are angularly equidistantly spaced from each other. In particular, the pipes 12 and 14 have a circular cross section. In this example, the outer surface of the outer tube 14 is substantially smooth.

[0040] Optionally, the channel 16 may be closed at its axial (ie longitudinal) ends. Alternatively, the ends of the channel 16 are open.

[0041] In particular, the sheath 15 is made by extrusion around the inner tube 12. In other words, the sheath 15 is made directly by extrusion around the inner tube 12 in a continuous process, thereby avoiding the need to later assemble the sheath 15 on the inner tube 12, which means higher costs and longer production times.

[0042] In particular, the passage 16 is located in a radially inner position relative to the outer tube 14. Such a passage 16 is radially interposed between the outer tube 14 and the inner tube 12. In more detail, the tubular portion 18 defining the passage 16 contacts the outer surface of the inner tube 12.

[0043] According to an illustrative embodiment of the present invention, the jacket 15 is made of a polymer material, such as an elastomer, in particular a thermoplastic elastomer, more particularly a vulcanized thermoplastic rubber, or TPV. Conveniently, the inner tube 12 is also made of a polymer material, which may be the same material as that used for the jacket 15, or a different material. For example, the inner tube 12 may be made of a polyamide or a polyolefin.

[0044] As described above, the conduit 10 can be used in a fluid carrier system.

[0045] According to an illustrative embodiment of the present invention, a fluid carrier system comprises a pipeline 10 and a fluid source, which is configured to supply the fluid to be transported. Such a fluid source is connected to an inner tube 12 of the pipeline 10.

[0046] As mentioned above, the conduit 10 is so versatile that it can be used in different types of systems.

[0047] According to an exemplary embodiment of the present invention, the channel 16 may be closed at its axial ends in order to provide thermal insulation for the fluid to be transported flowing through the inner tube 12. In this case, the fluid as the thermal insulator is preferably air.

[0048] According to an alternative exemplary embodiment, the pipeline is associated with a fluid circulation system, such as a fluid circulation system for gas or liquid, which is configured to supply an auxiliary fluid and is connected to the axial ends of the channel 16 and / or the void 17 so as to provide fluid circulation. Preferably, the axial ends of the channel 16 and / or the void 17 are open to allow the auxiliary fluid to circulate through them. The selected auxiliary fluid must have such properties as to provide heating or insulation for the fluid to be transported through the inner tube 12. Therefore, the thermal function of the pipeline 10 can be adjusted based on the desired performance of the system in which the pipeline 10 is to be installed. According to a possible variant, the channel 16 and / or the void 17 is filled with a fluid, such as a gas or a liquid, which is kept in a static state, that is, not circulating.

[0049] According to an exemplary embodiment, the system may be configured for cooling a battery of an electric or hybrid vehicle, wherein the fluid to be delivered is typically a solution of water and ethylene glycol, and the auxiliary fluid may be air contained in the channel 16 and the void 17. Alternatively, the system may be configured for selective catalytic reduction (SCR), wherein the fluid to be delivered is typically a urea solution, and the auxiliary fluid may be air contained in the channel 16. In this manner, the urea solution can be effectively heated by the combined effect of the heating device and the thermal insulation provided by the air contained in the channel 16 and the void 17.

[0050] according to Figure 1-5 In the variant shown, the tubular portion 18 is parallel to the longitudinal axis of the pipe 10. In particular, the tubular portion 18 is straight. When the pipe 10 is straight, and therefore its longitudinal axis is also straight, the tubular portion 18 is also straight. In this example, the tubular portion 18 is parallel to the outer tube 14 and the inner tube 12. In this example, the longitudinal axis of the pipe 10, in particular the longitudinal axis of the inner tube 12 and the outer tube 14 is straight. In particular, the pipe 10 is at least partially flexible, so that under some operating conditions (for example in a vehicle), the pipe 10 can be arranged so that its longitudinal axis is not completely straight. For example, the pipe 10 can be arranged so that its longitudinal axis is at least partially curved. Preferably, in the absence of any external forces, the pipe 10 is substantially straight.

[0051] On the other hand, Figure 6-11In the variant shown, the tubular portion 18 is arranged in a helical manner relative to the longitudinal axis of the pipe 10. When the pipe 10 is straight and therefore its longitudinal axis is also straight, the tubular portion 18 is arranged in a helical manner around the axis of the pipe 10. In this example, the tubular portion 18 is arranged in a helical manner relative to the outer pipe 14 and the inner pipe 12.

[0052] The fact that the tubular portion 18 extends in the longitudinal direction of the outer tube 14 applies both to those variants in which the tubular portion 18 is rectilinear and to those variants in which the tubular portion 18 is arranged in a spiral manner around the longitudinal axis of the pipe 10, in particular around the inner tube 12.

[0053] The helical arrangement of the tubular sections 18 is advantageous in larger pipes 10 for the following reasons. As the diameter of the pipe 10 increases, the width L of the arc of the portion of the outer pipe 14 separating the two (straight) tubular sections 18 may grow to a point where this portion of the outer pipe 14 may collapse under its own weight and bend towards the inner pipe 12. With the helically wound tubular sections 18, no longitudinal "corridor" is formed along which the arc of width L is not supported, because as large as the arc can be, it will still be supported by the previous and next sections of the helix. Thus, the helix helps to give stability to the arc of width L of the outer pipe 14, thereby avoiding the need to increase the number of tubular sections 18 (which constitute a thermal bridge) as the diameter of the pipe 10 increases.

[0054] In a first variant with a helical tubular portion 18 ( Figure 6-8 ), when viewed along a plane perpendicular to the direction of the spiral of the tubular portion, the cross-section of such tubular portion 18 is circular. Conversely, when viewed along a plane perpendicular to the longitudinal axis ( Figure 7 ) when viewed from above, the cross-section of the tubular portion 18 is not circular (in this case, it is elliptical). Figure 8 In the cross-sectional view of FIG. 1 , the tubular portion 18 is also not circular.

[0055] In the second variant with the helical tubular portion 18 ( Figure 9-11 ), when viewed along a plane perpendicular to the longitudinal axis of the pipe 10 ( Fig.10 ), the tubular portion 18 is circular. Fig.11 The cross section of the middle tubular portion 18 is not circular. The difference between the two variants described above derives from the respective production techniques used, in particular by extrusion.

[0056] The utility model also relates to a system for conveying fluid, the system comprising:

[0057] - a duct 10 according to any of the variants; and

[0058] A fluid source configured to supply the fluid to be transported and fluidically connected to the inner tube 12 of the pipeline 10 .

[0059] The utility model also relates to a motor vehicle equipped with the system.

[0060] A method for producing a pipe 10 for a fluid to be transported, in particular in a motor vehicle, comprises the following steps:

[0061] - providing an inner tube 12, said inner tube 12 being configured to be passed through by said fluid to be transported, and

[0062] - The sheath 15 is extruded around the inner tube 12, preferably in a continuous process, wherein the sheath 15 comprises:

[0063] - an outer tube 14, and

[0064] - A plurality of tubular portions 18 defining the passage 16. The tubular portions 18 are radially inserted between the inner tube 12 and the outer tube 14, extend longitudinally along the outer tube 14, are integrally formed with the outer tube 14, and are spaced apart from each other so as to form a gap 17.

[0065] The details of the conduit 10 have already been described and therefore will not be repeated for the sake of brevity.

[0066] Of course, without departing from the scope of the invention as set forth in the appended claims and without prejudice to the principle of the invention, the form and implementation details of the embodiments may be modified by way of non-limiting examples to those described and illustrated herein.

Claims

1. A pipeline (10) for conveying a fluid, the pipeline comprising: - an inner tube (12) configured to be passed through by the fluid to be transported, and - a sheath (15), said sheath comprising: - an outer tube (14), and - a plurality of tubular portions (18) defining a passage (16); Characterized in that the tubular portion (18): - radially inserted between the inner tube (12) and the outer tube (14), - extends longitudinally along the outer tube (14), - is made in one piece with the outer tube (14), - are spaced apart from each other, thereby forming a gap (17).

2. The pipeline for conveying fluid according to claim 1, characterized in that: The channels (16) and the voids (17) contain air.

3. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The sheath (15) is constructed around the inner tube (12) by extrusion.

4. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The width L of the gap (17) is greater than the width D of the outer surface of the tubular portion (18).

5. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The tubular portion (18) is in contact with the inner tube (12).

6. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The passage (16) is arranged circumferentially around the inner tube (12).

7. The pipeline for conveying fluid according to claim 6, characterized in that: The channels (16) are angularly equidistant from each other.

8. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The passage (16) is closed at its axial ends.

9. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The sheath (15) is made of elastomer.

10. The pipeline for conveying fluid according to claim 9, characterized in that: The elastomer is a thermoplastic elastomer.

11. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The inner tube (12) is made of polymer material.

12. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The tubular portion (18) is parallel to the longitudinal axis of the pipe (10).

13. The pipeline for conveying fluid according to claim 1 or 2, characterized in that: The tubular portion (18) is arranged in a helical manner relative to the longitudinal axis of the pipe (10).

14. The pipeline for conveying fluid according to claim 1, characterized in that: The pipeline for a fluid to be conveyed is a pipeline for a fluid to be conveyed in a motor vehicle.

15. A system for conveying fluid, characterized in that: It includes: - A pipe (10) for conveying a fluid according to any one of claims 1 to 14; and - a fluid source configured to supply the fluid to be transported and fluidically connected to the inner tube (12) of the pipeline (10).

16. A motor vehicle, characterized in that: It comprises a system according to claim 15.

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