Tubular fitting for conveying a coolant liquid to and from electric vehicle battery packs

Abstract

A tubular fitting (10) for conveying a coolant liquid to and from a battery pack comprises a tubular portion (11) defining a longitudinal axis (x), a flange (12) transversely protruding from the tubular portion (11) and having a flat surface (14) configured to support a gasket, and a thickened portion (16) transversely protruding from the tubular portion (11) and having a shaped surface (18) facing the flat surface (14) of the flange (12). The shaped surface (18) comprises a first (20) and a second (20) series of surfaces angularly spaced apart about the longitudinal axis (x) and offset therebetween. The first (20) and second (20) series of surfaces are respectively spaced by a first and a second axial distance from the flange (12) and are connected therebetween by means of a ramped surface (24).

Description

[0001] Tubular fitting for conveying a coolant liquid to and from electric vehicle battery packs

[0002] Technical field

[0003] The present invention relates to a tubular fitting. In particular, but not exclusively, the present tubular fitting may be used to convey a liquid for the cooling of electric vehicle battery packs.

[0004] Prior art

[0005] Electric vehicles such as cars, trucks and coaches are equipped with a battery pack that has to be hydraulically cooled during operation in order to avoid overheating of the battery and to hence operate the battery itself within a temperature range that allows for optimal operation of the battery whilst the vehicle is in motion. Furthermore, such cooling system is also used during battery charging, especially during fast charging, insofar as during this phase the battery temperature rises very quickly and reaches rather high temperatures and therefore it has to be cooled.

[0006] Battery cooling or coolant systems commonly have two tubular fittings that are engaged with the wall of the battery pack; the two fittings are used as inlet and outlet fittings, respectively, in order to convey or transfer a battery pack coolant liquid to and from the battery pack.

[0007] Cooling systems traditionally have a flange that is mounted, for example by screwing, onto the wall of the battery pack. The flange has two circular holes allowing for the passage of the two tubular fittings that connect the cooling circuit arranged inside the battery pack to the cooling circuit arranged outside the battery pack.

[0008] The flange is mounted on the outer wall of the battery pack and is usually screwed from the inside. The flange thus also has through seats for screwing those screws that are closed from the outside in such a way as to isolate the inside of the battery pack from the outside environment.

[0009] A peripheral gasket is also provided on the flange, which, in the mounted condition of the flange, faces the wall of the battery pack in order to ensure a vacuum and pressure seal against the flange on the wall of the battery pack, thus preventing dust from entering the battery pack.

[0010] Both the flange and the tubular fittings are made of a plastics material; the flange may for this reason be made by means of co-molding directly onto the tubular fittings. Alternatively, the flange is welded by means of ultrasound onto the tubular fittings. The co-molding technique and the ultrasonic welding technique make it possible to ensure a fluid seal between the flange and the tubular fittings.

[0011] The portion of the coolant system that passes through the wall of the battery pack, i.e., the portion of the coolant system comprising the flange and the tubular fittings, has a plurality of interface zones, such as the seats for screwing the flange to the wall of the battery pack, the engagement gasket between the flange and the wall of the battery pack, and the joining zone between the flange and each tubular fitting. In said interface zones, the required hermetic seal may fail, for example due to wear to one or more components, which hermetic seal is necessary in order to isolate the inside of the battery pack from the external environment.

[0012] Summary of the invention

[0013] A primary object of the present invention is to provide a tubular fitting that is easy and quick to mount. In particular, it is desired to provide a tubular fitting that also allows relative disassembly for maintenance and / or replacement operations.

[0014] Another object of the invention is to provide a tubular fitting having a reduced number of components.

[0015] A further object of the present invention is to reduce the number of preliminary operations to be performed during the assembly step of the tubular fitting.

[0016] The aforesaid and other objects and advantages, which will be better understood hereinafter, are achieved according to one aspect of the present invention by a tubular fitting having the features set forth in the independent claim 1, as well as by a conveying assembly as defined in the accompanying claim 6. Preferential embodiments of the invention are defined in the dependent claims.

[0017] In short, according to a first aspect of the invention, a tubular fitting for conveying a coolant liquid towards and away from an electric vehicle battery pack comprises at least one tubular portion defining a longitudinal axis, a flange extending transversely protruding from the tubular portion and forming at least one flat surface, and a thickened portion extending transversely protruding from the tubular portion and having a shaped surface facing the flat surface of the flange. The shaped surface forms a plurality of first surfaces angularly spaced apart about the longitudinal axis and spaced at a first axial distance from the flange, and a plurality of second surfaces angularly spaced apart about the longitudinal axis and spaced at a second axial distance, less than the first distance, from the flange. The second surfaces are offset angularly with respect to the first surfaces, and each second surface is connected to a relevant first surface by means of a ramped surface.

[0018] According to a second aspect of the invention, a conveying assembly configured to convey a liquid for cooling an electric vehicle battery pack comprises at least one tubular fitting, a wall of a battery pack having at least one through opening shaped in a manner corresponding to the thickened portion of the tubular fitting, and also having a first face predisposed to face in use towards the flat surface of the flange, and at least one annular gasket configured to be arranged in use between the first face of the wall and the flat surface of the flange.

[0019] Brief description of the drawings

[0020] The features and advantages of the present invention will be evident from the following description, given by way of non-limiting example. Reference is made to the appended drawings, wherein:

[0021] Figure 1 is a perspective view of a tubular fitting according to the present invention;

[0022] Figure 2 is a side view of the tubular fitting of Figure 1 ;

[0023] Figure 3 is a front view of the tubular fitting of Figure 1 ; Figure 4 is a top view of the tubular fitting of Figure 1 ;

[0024] Figure 5 is a perspective view of a conveying assembly according to the present invention;

[0025] Figure 6 is a side view in cross section of the conveying assembly of Figure 5;

[0026] Figure 7 is an exploded perspective view of the conveying assembly of Figure 5;

[0027] Figure 8 shows a shaped opening in a wall of a battery pack;

[0028] Figures 9-11 are elevated views of the conveying assembly in an angular insertion position, an intermediate angular position, and a mounted position, respectively;

[0029] Figures 12-14 are top views of the conveying assembly of Figures 9-11, respectively; and

[0030] Figures 15-17 are bottom views of the conveying assembly of Figures 9-11, respectively.

[0031] Detailed description

[0032] Referring to Figures 1 to 4, a tubular fitting 10 for conveying or transferring a liquid for cooling a battery pack towards and away from an electric vehicle battery pack comprises a flange 12 and a thickened portion 16 which allow the tubular fitting 10 to be fixed to a wall of a battery pack.

[0033] The tubular fitting 10 has at least one tubular portion 11 that defines a longitudinal axis x. In the illustrated embodiment, the tubular fitting 10 has an angular shape and has two tubular portions 11 and 13, joined by an elbow portion 15 (Figures 1-4).

[0034] The flange 12 has a flat surface 14 extending in a plane transverse to the longitudinal axis x, preferably in a plane perpendicular to the longitudinal axis x; the flat surface 14 is configured when in use to support an annular seal 40.

[0035] In the present description and in the appended claims, terms and references indicating directions such as "axial," "longitudinal," "radial" and "transverse" are to be interpreted with reference to the longitudinal axis x, unless otherwise noted. Preferably, the flange 12 has the shape of an annular or discoidal plate that extends transversely protruding from the tubular fitting and forming an outer edge which is circular in the example shown in the figures. The shape of the outer edge of the flange is not intended to be limiting. For example, the flange 12 may have a relative outer perimeter of a square, rectangular, elliptical, or polygonal shape.

[0036] The thickened portion 16 extends transversely protruding about the tubular fitting 10. Preferably, the thickened portion 16 has a maximum transverse dimension, measured in the radial direction with respect to the longitudinal axis x, which is smaller than the transverse dimension or diameter of the flange 12.

[0037] The thickened portion 16 has a shaped surface 18 that faces the flat surface 14 of the flange 12. The shaped surface 18 comprises a plurality or series of first surfaces 20, angularly spaced apart about the longitudinal axis x and spaced by a first axial distance from the flange 12 and a plurality or series of second surfaces 22 angularly spaced apart about the longitudinal axis x and spaced by a second axial distance, which is smaller than the first distance, relative to the flange 12.

[0038] In particular, the plurality of first surfaces 20 and the plurality of second surfaces 22 may be spaced by a first distance and a second distance, respectively, from the flat surface 14 of the flange 12.

[0039] The second surfaces 22 are angularly offset with respect to the first surfaces 20, as shown in Figure 2, and each second surface 22 is connected to a relevant first surface 20 by means of a ramped or inclined surface 24.

[0040] Preferably, the first surfaces 20 and the second surfaces 22 are parallel therebetween, lying in planes that are axially spaced apart and perpendicular to the longitudinal axis x, as shown in Figures 2 and 3.

[0041] In an alternative embodiment that is not shown in the figures, the first surfaces 20 and the second surfaces 22 may lie on mutually inclined planes. For example, the first surfaces 20 and the second surfaces 22 may lie on planes that are inclined therebetween by an angle of between 1° and 5°.

[0042] Additionally or alternatively, the first surfaces 20 and the second surfaces 22 may lie on planes that are inclined with respect to the longitudinal axis x. For example, the first surfaces 20 and the second surfaces 22 may lie on planes that are inclined with respect to the longitudinal axis x at an angle of between 1° and 5°.

[0043] The first surfaces 20, the second surfaces 22 and the ramped surfaces 24, present in the tubular fitting 10 and configured as described above, may allow for a bayonet coupling between the tubular fitting 10 and a wall of a battery pack.

[0044] In a preferred embodiment, the tubular fitting 10 may have four first surfaces 20 and four second surfaces 22 connected therebetween by means of a relative ramped surface 24. Depending upon requirements, the number of first and second surfaces may be different from four; for example, there may be three or five first and second surfaces.

[0045] Figures 1-4 show an embodiment wherein the first surfaces 20 and the second surfaces 22 are angularly equidistant therebetween about the longitudinal axis x so as to increase, in use, the seal with the wall of the battery pack.

[0046] Preferably, the thickened portion 16 has an overall asymmetrical polygonal shape when viewed in an axial direction. In other words, the perimeter of the projection of the thickened portion 16 in a plane perpendicular to the longitudinal axis x has an asymmetrical polygonal shape. For example, in the embodiment illustrated in Figure 4, the perimeter of the projection of the thickened portion 16 has a substantially square shape with three beveled or rounded vertices with a first curvature and a fourth beveled or rounded angle with a second curvature that is different from the first curvature. This asymmetrical polygonal shape of the thickened portion 16 allows the tubular fitting 10 to have a unique engagement position with the wall of the battery pack, thereby facilitating the relative coupling on the part of an operator.

[0047] Alternative embodiments, that are not shown in the figures, may provide for the tubular fitting to have a thickened portion having a symmetrical polygonal shape when viewed in an axial direction. In other words, the perimeter of the projection of the thickened portion on a plane perpendicular to the longitudinal axis of the tubular fitting may have a symmetrical polygonal shape.

[0048] Preferably, the tubular fitting 10 has an angular shape and has two opposite open ends 26, 28, wherein the first end 26 is predisposed to be arranged in use on the outside of a wall 32 of a battery pack and the second end 28 is predisposed to be arranged in use on the inside of the wall 32 of the battery pack.

[0049] Figures 1-4 show an angular- shaped tubular fitting 10 wherein the tubular portion 13 is perpendicular to the longitudinal axis x of the tubular portion 11. The two tubular portions may form an angle therebetween that is different from 90°, for example 135°.

[0050] In an alternative embodiment that is not shown in the figures, the first end 26 and the second end 28 may be axially aligned. In other words, the tubular fitting may have an overall cylindrical and rectilinear shape.

[0051] The tubular fitting 10 of the present invention may consist at least partially of a plastics material selected from the group consisting of polyamide, phenolic resins, polyethylene, polyphenylene sulfide and combinations thereof. For example, it may be made by molding. Insofar as the flange 12 and the thickened portion 16 are made of a plastics material, they may advantageously be joined to the tubular portion 11 of the tubular fitting 10, i.e., the flange 12 and the thickened portion 16 may be made as one piece or integrally with the tubular portion 11 of the tubular fitting 10, thereby increasing, during use, the seal and insulation between the inside and outside of the battery pack.

[0052] Advantageously the tubular fitting 10, object of the present invention, also makes it possible to simplify the process for producing the same insofar as it appears as a single object having a zone for engaging and sealing against a wall of a battery pack that may be obtained by means of a single molding process. The present invention also relates to a conveying assembly 30, illustrated in Figures 5-7, configured to convey or transfer a liquid for cooling an electric vehicle battery pack towards and away from the battery pack. The conveying assembly 30 comprises at least one tubular fitting 10 according to any one of the embodiments described above, at least one annular gasket 40 and one wall 32 of an electric vehicle battery pack.

[0053] The wall 32 of the battery pack has at least one through opening 34 (Figure 8) which is shaped in a manner corresponding to the thickened portion 16 of the tubular fitting 10 so that the tubular fitting 10 may be inserted at least partially through the wall 32. In other words, the wall 32 of the battery pack has at least one opening 34 shaped in a manner corresponding to the perimeter of the projection of the thickened portion 16 in a plane perpendicular to the longitudinal axis x.

[0054] Preferably, the flange 12 of the tubular fitting 10 has a greater transverse dimension than the maximum dimension of the opening 34 in the wall 32 of the battery pack so that, in use, the flange 12 is arranged on one side of the wall 32 and the thickened portion 16 of the tubular fitting 10 is arranged on the opposite side of the wall 32, as shown in Figures 5 and 6.

[0055] The wall 32 of the battery pack has a first face 36, predisposed to face, in use, towards the flat surface 14 of the flange 12 of the tubular fitting 10, and may also comprise a second face 38 that is opposite to the first face 36 (Figure 6 and 7).

[0056] In a preferred embodiment, the first face 36 is the inner face of the battery pack and the second face 38 is the outer face of the battery pack.

[0057] Preferably, in use, the conveying assembly 30 is configured so that the flange 12 of the tubular fitting 10 is arranged inside the battery pack and the thickened portion 16 of the tubular fitting 10 is arranged outside the battery pack (Figures 5 and 6).

[0058] In an alternative embodiment that is not shown in the figures, the conveying assembly may be configured so that the flange of the tubular fitting is arranged outside the battery pack and the thickened portion of the tubular fitting is arranged inside the battery pack. The annular gasket 40 is configured to be arranged in use between the first face 36 of the wall 32 of the battery pack and the flat surface 14 of the flange 12 of the tubular fitting 10 (Figure 6). Preferably, the gasket may be arranged between the inner face of the battery pack and the flat surface 14 of the flange 12 of the tubular fitting 10, in such a way as to be arranged within the battery pack.

[0059] Preferably, the annular gasket 40 may have a relative outer perimeter of a circumferential, square, rectangular, elliptical, or polygonal shape.

[0060] According to the present invention, the tubular fitting 10 of the conveying assembly 30 may assume, with respect to the wall 32 of the battery pack, an angular insertion position, an intermediate position and a mounted position.

[0061] The angular insertion position is a position wherein the tubular fitting 10 is oriented angularly with respect to the longitudinal axis x thereof so as to have the thickened portion 16 axially aligned with the through opening 34 of the wall 32 (Figure 9, 12 and 15), in such a way as to insert the thickened portion 16 through the opening 34 of the wall 32 of the battery pack.

[0062] Preferably, this angular insertion position is a uniquely determined position insofar as the thickened portion 16 of the tubular fitting 10 and the opening 34 present within the wall 32 of the battery pack have a corresponding asymmetrical polygonal shape which allows for a unique orientation to be defined between the tubular fitting 10 and the wall 32 of the battery pack, thereby simplifying manual insertion on the part of an operator. In other words, a peripheral contour of the thickened portion 16 and an edge of the through opening 34 of the wall may be corresponding and aligned during the insertion of the tubular fitting 10 into the wall 32 of the battery pack.

[0063] In the insertion position, the first face 36 of the wall 32 and the flat surface 14 of the flange 12 are spaced apart by a third axial distance, and the gasket 40 may be interposed within the free space that is present between the first face 36 of the wall 32 and the flat surface 14 of the flange 12 (Figure 9).

[0064] After the tubular fitting 10 has been manually inserted by an operator into the opening 34 present within the wall 32 of the battery pack, the tubular fitting 10 may be rotated by a certain angle with respect to the wall 32 of the battery pack. Following such rotation, the tubular fitting 10 is in the intermediate angular position (Figures 10, 13, 16), a position wherein the ramped surfaces 24 of the thickened portion 16 are engaged against the second face 38 of the wall 32. Furthermore, with the angular rotation that conveys the tubular fitting 10 to the intermediate position, the gasket 40 supported by the flat surface 14 of the flange 12 is brought close to, and partially compressed against, the first face 36 of the wall 32 of the battery pack (Figure 10).

[0065] A further rotation of the tubular fitting 10 on the part of the operator conveys the tubular fitting 10 to the mounted position (Figures 11, 14, 17), a position wherein the second surfaces 22 engage against the second face 38 of the wall 32.

[0066] When the tubular fitting 10 is in the mounted position on the wall 32 of the battery pack, the first face 36 of the wall 32 and the flat surface 14 of the flange 12 of the tubular fitting 10 are spaced apart by a fourth axial distance, less than the third axial distance they had assumed in the insertion position, and the gasket 40 is compressed between the first face 36 of the wall 32 of the battery pack and the flat surface 14 of the flange 12, thereby forming a circumferentially continuous hermetic seal about the tubular fitting 10.

[0067] In the mounted position, the shaped surface 18 of the tubular fitting 10, the wall 32 of the battery pack, the gasket 40 and the flat surface 14 of the flange 12 assume a sandwich configuration allowing for locking and a vacuum and pressure seal of the tubular fitting 10 with respect to the wall 32 of the battery pack.

[0068] The hermetic sealing condition of the conveying assembly 30 is also obtained insofar as the distance in the axial direction between the first surfaces 20 and the second surfaces 22 is less than the overall dimension in the axial direction of the gasket 40 and of the wall 32 of the battery pack. Preferably, in order to move from the engagement position to the mounted position, the tubular fitting 10 may be rotated on the part of the operator with respect to the wall 32 of the battery pack by an angle in the range of between 30° and 90°. Even more preferably, the tubular fitting 10 may be rotated by an amount equal to 45°. The tubular fitting 10 may be configured to be rotated by a different angle, for example 60°.

[0069] The conveying assembly 30 of the present invention also simplifies and accelerates the relative assembly on the part of an operator insofar as, for each tubular fitting 10, only one opening 34 may advantageously be made in the wall 32 of the battery pack wherein the tubular fitting 10 may be threaded and the tubular fitting 10 may be locked against the wall 32 by means of a single rotation due to the engagement of the bayonet configuration.

[0070] Those tubular fittings of the conveying assembly 30 having a bayonet configuration may also be advantageously removed after the insertion thereof by means of rotating the tubular fitting in reverse, for example for maintenance and / or replacement operations.

[0071] Preferably, the conveying assembly 30 comprises two tubular delivery and inlet fittings 10, respectively, which may be mounted in relative openings 34 made in the wall 32 of the battery pack and which may be hermetically sealed therewith by means of the bayonet configuration and the presence of a relative gasket 40 which is compressed between the flat surface 14 of the flange 12 of each tubular fitting 10 and the first face 36 of the wall 32 of the battery pack. Wherein the openings 34 in the wall 32 are through openings and shaped in a manner corresponding to the thickened portions 16 of the two tubular fittings 10 and the wall 32 has a first face 36 predisposed to face, in use, towards the flat surfaces 14 of the flanges 12 of the two tubular fittings.

[0072] Whilst specific embodiments of the invention have been described, it is to be understood that this disclosure has been provided for illustrative purposes only and that the invention is not to be limited in any way thereby. Various modifications will be evident to those skilled in the art in the light of the preceding examples. The scope of the invention is limited only by the appended claims.

Claims

CLAIMS1. A tubular fitting (10) for conveying a coolant liquid towards and away from an electric vehicle battery pack, said tubular fitting (10) comprising:- at least one tubular portion (11) which defines a longitudinal axis (x);- a flange (12) which extends transversely protruding from the tubular portion (11) and forms at least one flat surface (14); and- a thickened portion (16) which extends transversely protruding from the tubular portion (11) and which has a shaped surface (18) facing the flat surface (14) of the flange (12), said shaped surface (18) forming:- a plurality of first surfaces (20) angularly spaced apart about the longitudinal axis (x) and spaced by a first axial distance from the flange (12); and- a plurality of second surfaces (22) angularly spaced apart about the longitudinal axis (x) and spaced by a second axial distance, that is less than the first distance, from the flange (12); wherein the second surfaces (22) are offset angularly with respect to the first surfaces (20); and wherein each second surface (22) is connected to a relevant first surface (20) by means of a ramped surface (24).

2. A tubular fitting (10) according to claim 1, wherein the first surfaces (20) and the second surfaces (22) are parallel therebetween, lying in planes that are axially spaced apart and perpendicular to the longitudinal axis (x).

3. A tubular fitting (10) according to claim 1 or 2, wherein the thickened portion (16) has an asymmetrical polygonal shape.

4. A tubular fitting (10) according to any one of the preceding claims, wherein the tubular fitting (10) has an angular shape and forms two opposite open ends (26, 28), wherein the first end (26) is predisposed to be arranged in use outside a wall of a battery pack and the second end (28) is predisposed to be arranged in use inside the wall of the battery pack.

5. A tubular fitting (10) according to any one of the preceding claims, wherein the tubular fitting (10) consists at least partially of a plastics material selected from the group consisting of polyamide, phenolic resins, polyethylene, polyphenylene sulfide and combinations thereof.

6. A conveying assembly (30) configured to convey a liquid for cooling an electric vehicle battery pack, said assembly comprising:- at least one tubular fitting (10) according to any one of the preceding claims,- a wall (32) of a battery pack having at least one through opening (34) shaped in a manner corresponding to the thickened portion (16) of the tubular fitting (10), and also having a first face (36) predisposed to face in use towards the flat surface (14) of the flange (12), and- at least one annular gasket (40) configured to be arranged in use between the first face (36) of the wall (32) and the flat surface (14) of the flange (12).

7. A conveying assembly (30) according to claim 6, wherein the tubular fitting (10) is capable of assuming the following positions:- an angular insertion position, wherein the tubular fitting (10) is oriented angularly with respect to the longitudinal axis (x) thereof in such a way as to have the thickened portion (16) axially aligned with said through opening (34) in such a way as to couple the tubular fitting (10) to the wall (32) of the battery pack by inserting the thickened portion (16) through the opening (34) of the wall (32), the first face (36) of the wall (32) and the flat surface (14) of the flange (12) are spaced apart by a third axial distance, and the gasket (40) is interposed between the first face (36) of the wall (32) and the flat surface (14) of the flange (12);- an intermediate angular position, wherein the ramped surfaces (24) of the thickened portion (16) engage against a second face (38) of the wall (32), and- a mounted position, wherein the second surfaces (22) are engaged against the second face (38) of the wall (32), the first face (36) of the wall (32) and the flat surface (14) of the flange (12) are spaced apart by a fourth axial distance, which is less than the third axial distance, and the gasket (40) is compressed between the first face (36) of the wall (32) and the flat surfacetubular fitting (10).

8. A conveying assembly (30) according to claim 6 or 7, wherein between the angular insertion position and the mounted position the tubular fitting (10) is rotated with respect to the wall (32) by an angle of between 30° and 90°.

9. A conveying assembly (30) according to any one of the claims from 6 to 8, comprising:- two tubular fittings (10) according to any one of the preceding claims, configured to convey a coolant liquid to and from an electric vehicle battery pack, respectively,- a wall (32) of a battery pack having two of said through openings (34) shaped in a manner corresponding to the thickened portions (16) of the two tubular fittings (10), the wall (32) having a first face (36) predisposed to face in use towards the flat surfaces (14) of the flanges (12) of the two tubular fittings (10), and - two annular gaskets (40) each configured to be arranged in use between the first face (36) of the wall (32) and the flat surface (14) of a relevant flange (12) of the two tubular fittings (10).

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