WO2021033923A1

WO2021033923A1 - Plastic cooler and battery having such a cooler

Info

Publication number: WO2021033923A1
Application number: PCT/KR2020/009357
Authority: WO
Inventors: David RICICA; Jirí KUCERA
Original assignee: Hanon Systems
Priority date: 2019-08-19
Filing date: 2020-07-16
Publication date: 2021-02-25
Also published as: DE102019212361A1

Abstract

A plastic cooler comprises at least one tube (12) that is connected to a header (14) by means of ultrasonic welding, and is characterised in that the header (14) comprises a tube section (28) extending in the longitudinal direction of the tube (12) and a flange (30) extending substantially perpendicular thereto, and a weld between the header (14) and the tube (12) is provided in the region of the tube section (28) and at a distance from the flange (30).

Description

PLASTIC COOLER AND BATTERY HAVING SUCH A COOLER

The invention relates to a plastic cooler as well as to a battery having such a cooler.

In particular in the field of electromobility, it is necessary to provide coolers for the batteries used in order to cool them in certain operating conditions and situations. Such coolers are often made of plastic, and they can thus be manufactured comparatively inexpensively. When used, they are located, for example, between individual battery cells.

Known from KR 10-20090107192A and DE 39 27 955 A1 are heat exchangers made of plastic, in which individual components are welded together by means of ultrasound, and projections and/or grooves are provided in the weld regions so as to reliably implement connection.

The object forming the basis for the invention is to provide a cooler made of plastic, in which the connection, in particular between individual tubes and a header, can be further improved.

This object is solved by the cooler according to patent claim 1.

According thereto, the cooler is made of plastic and comprises at least one tube that is connected by means of ultrasonic welding to a header comprising a tube section extending in the longitudinal direction of the tube and a flange substantially perpendicular thereto. According to the invention, the weld between the header and the tube is formed in the region of the tube section. By means of the tube section, the header is extended to a certain extent in the direction of extension of the tube such that a comparatively large connecting surface is available for ultrasonic welding, and welding can be carried out particularly reliably. It is in particular made possible for a device used for welding to act over a particularly large surface area such that the weld can be formed particularly reliably. The header and/or the header tank mentioned below can be produced by means of injection moulding. The use of plastic and ultrasonic welding makes the cooler comparatively lightweight and inexpensive to produce, in particular as compared to an aluminium cooler. Furthermore, no measures are required with regard to electrical insulation.

Preferred developments of the cooler according to the invention are described in the further claims.

If the tube section comprises a widening on the inner side at its end directed towards the tube, this facilitates access for a welding device to the interface between the tube and the tube section of the header. The widening can be configured as a bevel or as a rounded inner edge, curved in cross-section, in such a manner that the interior of the tube section gradually widens in the direction of the tube to be inserted.

The header is furthermore typically connected by means of ultrasonic welding to a header tank, the wall of which that defines the interior of the header tank being at least substantially flush with the interior of the tube. If the cited inner walls are substantially flush, this has the advantage of particularly low flow losses in both flow directions. If, at the point in question, the cooling fluid flows from the tube into the header tank, the inner wall of the tube can be arranged inside that of the header tank. Similarly, at a point where the cooling fluid flows from the header tank into the tube, the inner wall of the header tank can be located inside that of the tube in order to keep flow resistance and losses low.

The end of the tube is furthermore preferably flush, in a direction perpendicular to the direction of extension of the tube, with the end of the header facing away from the tube section. In other words, the two cited ends lie in one plane such that the header tank can be connected flat here, no recesses or the like occur as a result of misalignment, and the header tank can act as a stop for the tube during production. This is particularly advantageous if the header and the header tank are first of all connected and then the tube or tubes are inserted. However, the reverse approach is also conceivable, i.e. that the header and the tube are first of all connected and then the header tank is attached. In any case, both when the header and the tube are connected and when the header and the header tank are connected, the long sides, as shown in the figures, can first of all be welded and then the rounded ends. If the tube is first of all connected to the header, this has the advantage that a support structure can be inserted into the tube opening to prevent deformation of the tube during welding and ensure a good connection with the header. In this case, the header may furthermore comprise a stop for the tube.

It has proven to be advantageous for the connection between the header and the header tank if at least one of the two components comprises a flange, at which it is connected to the respective other component. A large connecting surface can be provided by means of a flange, which enables extensive access for a welding tool and makes it possible to form the connection in a particularly reliable manner.

Such a flange and/or the tube section of the header preferably comprises at least one projection, which, in the case of the flange, can be inserted into a groove on the opposite flange to further improve the ultrasonic connection. Similarly, a projection on the tube section of the header leads to an improved connection with the tube. The projection can, for example, be in the form of a bar with an approximately triangular cross-section or a rib of this type.

If a projection is formed on one flange and a groove is formed on another, it is advantageous if the projection has a smaller extension perpendicular to the joining direction than the groove in order to facilitate the arrangement of the projection in the groove.

It is furthermore advantageous if the projection on one flange has a greater extension in the joining direction than the groove on the other flange, and/or if the tube does not comprise a groove in the region of the projection formed on the tube section. This provides additional material in the form of the projection for reliable ultrasonic welding.

Preferably the tube is a flat tube and the header tank comprises a substantially cylindrical inlet or outlet. For an undisturbed flow, the flow cross-sections of the inlet or outlet on the one hand and the tube on the other hand can be substantially the same.

As regards the production of the tube, in particular as a flat tube with a plurality of flow channels delimited by walls, it is advantageous for production, for example by extrusion, if all wall thicknesses are substantially the same. Deformation during cooling owing to shrinkage can be prevented as a result hereof.

As explained at the start, the cooler according to the invention is in particular suitable as a cooler for a battery, and a battery having such a cooler is to be regarded as subject matter of the present application.

An embodiment example of the invention as shown in the figures will be explained in more detail below. The drawings show:

Fig. 1 a perspective view of a section of the cooler according to the invention;

Fig. 2 a perspective exploded view of the same section;

Fig. 3 a cross-sectional view of the tube of the cooler according to the invention;

Fig. 4 a perspective sectional view of the header;

Fig. 5 a perspective sectional view of the header tank;

Fig. 6 a sectional view of the tube connected to the header; and

Fig. 7 a sectional view in the region of the section shown in Fig. 1.

As is apparent in Fig. 1, the cooler 10 according to the invention essentially comprises a flat tube 12, a header 14 and a header tank 16, all of which are explained in more detail below. As regards the header tank 16, it can best be seen in Fig. 1 that in the shown case, it asymmetrically comprises a substantially cylindrical inlet or outlet 18.

It is apparent from Fig. 2 that the connection between the header tank 16 and the header 14 occurs by means of a flange 20 formed on the header tank 16 and a similar flange 30 on the header 14.

Fig. 3 shows the design of the flat tube with a plurality of flow channels 24 extending in parallel and separated from one another by means of a plurality of walls 26. These walls, like the outer walls of the flat tube, have a wall thickness of approximately 0.4 mm, for example. However, this thickness can also be higher or lower, for example between 0.18 and 1.0 mm, in particular also approximately 0.27 mm. In the shown example, the width of each flow channel, measured from right to left in Fig. 3, is approximately 5.5 mm, and the flat tube is approximately 5 mm high, and thus owing to the two wall thicknesses of 0.4 mm, there is an internal clear height of the flow channels of approximately 4.2 mm. The left and right ends of the flat tube have an internal radius of approximately 2.1 mm and the width of the outermost left and outermost right flow channel is approximately 5 mm. The cited dimensions are merely provided as examples and relate to a so-called 88 mm tube. However, a tube width of, for example, 50 mm is also possible, with correspondingly adapted dimensions as specified above. The width of the tube can, for example, be in the range of 48 to 90 mm.

Fig. 4 shows the header 14 connected thereto in a perspective sectional view. Shown in this figure is, on the one hand, the tube section 28 that is directed towards the tube 12 and, on the other hand, the flange 30 of the header 14 that extends substantially perpendicular to the longitudinal extension of the tube 12 and thus to the direction of flow. The shape of the tube section 28 hereby essentially corresponds to the cross-sectional shape of the tube according to Fig. 3, and thus the tube section 28, as can be seen more precisely in Fig. 6, flatly abuts the outer wall of the tube in the region of its end around the entire circumference. The outer contour of the flange 30 is essentially concentric hereto, in other words, the flange 30 extends parallel to the outer walls of the tube on its long sides and its ends are rounded, as is apparent at the top of Fig. 4. Parallel to this outer contour, the flange is provided with a circumferential groove 32 that is used for connection with the header tank 16, as will be explained in more detail below.

The tube section 28 is provided on its inner side with a likewise circumferential projection 34 in the form of a rib that is essentially triangular in cross-section and serves to provide a reliable connection to the tube 12. As is apparent in Fig. 4, this rib 34, and thus the area of connection with the tube 12, is formed in the region of tube section 28 and, in particular, at a distance from flange 30 such that particularly good access for tools used for ultrasonic connection is possible.

Shown in Fig. 5 is a cross-section of the design of the header tank 16 in the region of the inlet or outlet 18. As is apparent in Fig. 4, the inlet or outlet 18 is provided approximately in the middle of its extension with a thickening 36, a groove 38 and an insertion bevel 40, which aid attachment to an adjacent component. A quasi two-stage projection 42 can also be seen in the lower region of the header tank, the first part of which, that is located closer to the flange 20, consists of a shoulder having a shape that is essentially complementary to that of the groove 32 on the header 14 (see Fig. 4). A rib that is essentially triangular in cross-section, which is similar to the rib 34 formed on the header, is attached thereto and ensures a good connection to the header 14. The groove 32 can also be formed on the flange 20 of the header tank 16, and the projection 42 can be formed on the flange 30 of the header 14.

Fig. 6 first of all shows the connection between the tube 12 and the header 14. It is mentioned in this regard that the projection 34 on the tube section 28 of the header 14 is located essentially in the middle along its extension in the longitudinal direction of the tube (vertical in Fig. 6). The end of tube 12 is furthermore essentially flush with the flange 30 of the header.

As is additionally apparent from Fig. 7, any gaps or recesses when connecting to the (flat) flange 20 of the header tank 16 can be prevented as a result hereof. It is furthermore apparent in Fig. 7 that the inner wall of the tube (12) is essentially flush with that of the header tank 16, and thus pressure losses can be prevented in both flow directions. If the header 14 and the header tank 16 are connected in a first step, an inner wall of the header tank 16, which is further inward than the inner wall of the header 14, can act as a stop for the tube 12 to be inserted. In the region of tube section 28 of header 14, a widening 44 can also be seen at the end thereof in Fig. 7, which facilitates the insertion of the tube 12. The

flanges

20, 30 of the header tank 16 and the header 14 have approximately the same extension in the radial direction (right and left in Fig. 7).

Claims

Cooler (10) made of plastic comprising at least one tube (12) that is connected to a header (14) by means of ultrasonic welding,

characterised in that

the header (14) comprises a tube section (28) extending in the longitudinal direction of the tube (12) and a flange (30) extending substantially perpendicular thereto, and a weld between the header (14) and the tube (12) is provided in the region of the tube section (28) and at a distance to the flange (30).
Cooler (10) according to claim 1,

characterised in that

the tube section (14) comprises a widening (44) on the inner side at its end directed towards the tube (12).
Cooler (10) according to claim 1 or 2,

characterised in that

the header (14) is connected to a header tank (16), and a wall defining the interior of the tube (12) is at least substantially flush with a wall defining the interior of the header tank (16).
Cooler (10) according to one of the preceding claims,

characterised in that

one end of the tube (12) is substantially flush with an end of the header (14) facing away from the tube (12).
Cooler (10) according to one of the preceding claims,

characterised in that

the header (14) and/or the header tank (16) comprises a flange (30, 20), at which it is connected to the header tank (16) or the header (14).
Cooler (10) according to one of the preceding claims,

characterised in that

a flange (30, 20) and/or the tube section (28) of the header (14) comprises a projection (34, 42).
Cooler (10) according to claim 6,

characterised in that

one flange (30) comprises a groove (32) and one flange (20) comprises a projection (42), wherein the projection (42) has a smaller extension perpendicular to the joining direction than the groove (32).
Cooler (10) according to claim 6 or 7,

characterised in that

one flange (30) comprises a groove (32) and one flange (20) comprises a projection (42) which has a greater extension than the groove (32) in the joining direction.
Cooler (10) according to one of the preceding claims,

characterised in that

the tube (12) is a flat tube.
Cooler (10) according to one of the preceding claims,

characterised in that

the tube comprises a plurality of flow channels (24), and the walls (26) between the flow channels and the outer walls of the tube (12) have substantially the same thickness.
Cooler (10) according to one of the preceding claims,

characterised in that

the header tank (16) comprises a substantially cylindrical inlet or outlet (18).
Cooler (10) according to one of the preceding claims,

characterised in that

the cooler is a cooler for a battery.
A battery comprising at least one cooler (10) according to at least one of the preceding claims.