Brazing assembly process and product resulting from the process

Abstract

Title: Brazing Assembly Method and Product of the Process The invention relates to an induction brazing method for joining a first part (1) to a second part (2) at a contact line (3). At least the first part (1) has a raised feature (4) which forms a chamber (5), said chamber being located at the contact line. The method comprises the following steps: - Deposition of a brazing wire (6) in said chamber; - Closure of the chamber by joining the second part (2) to the first part; - Heating at least the brazing wire by induction so as to melt it. Said contact line forms a plane (P) which virtually cuts the brazing wire (6) into two parts, each part representing between 40% and 60% of the total cross-section of the brazing wire. Figure for the abstract: Fig. 1

Description

Title of the invention: Brazing assembly method and product resulting from the process

[0001] The present invention relates to a brazing assembly method and the resulting product, in particular a thermal regulation device for electrical and / or electronic components, particularly in the automotive field.

[0002] Parts that can be assembled by brazing are all parts having a high melting point, in particular metallic parts, allowing the use of a brazing wire having a lower melting point.

[0003] The electrical and / or electronic components that may be relevant to the present invention may be electrical energy storage elements, in particular battery components, or power electronics components, for example, but not limited to, semiconductors such as diodes or transistors. They could also include computer server components.

[0004] The invention finds an advantageous application in the field of thermal regulation devices of a device, in particular by the need in this field to have a reliable seal between two metal parts.

[0005] Indeed, assembly by screwing or force may be unreliable, damage, or even destroy one of the parts. Furthermore, for large production volumes, such a process can be costly and / or time-consuming.

[0006] In the prior art, a solution has been proposed consisting of a brazing process in large furnaces. The parts to be brazed are pre-assembled and then heated entirely to the melting point of the brazing wire, which melts the wire to bond the assembly.

[0007] One disadvantage of this solution is that brazing the entire part requires large furnaces, sized according to the size of the parts to be assembled. Another disadvantage is the energy cost of such a process, which results in a significant carbon footprint for production.

[0008] The present invention makes it possible to solve at least some of the problems of the prior art by proposing an induction brazing process, therefore localized, which makes it possible to do without large traditional brazing furnaces and thus to reduce the carbon footprint of manufacturing the assembled part.

[0009] The invention thus relates to an induction brazing method of a first part with a second part at a contact line at which the two parts are in contact to be joined by brazing, at least the first part, in particular the two parts, having a relief, in particular a groove, which forms a chamber when the first piece is brought into contact with the second piece to be brazed, said chamber being at the level of the contact line, the brazing process comprising the following steps: - Depositing a brazing wire in the said chamber formed by the said relief of at least the first piece, - Closing the chamber by assembling the second piece with the first piece; - Heat at least the brazing wire by induction heating so as to melt it; the process being characterized in that the brazing wire is arranged in said chamber at the level of the contact line so that said contact line forms a plane (P) which virtually cuts the brazing wire into two parts, each part representing between 40% and 60% of the total cross-section of the brazing wire, in particular between 45% and 55%.

[0010] This advantageously allows for a localized brazing process that is less energy-intensive and more precise, making it possible to assemble several parts, some of which may be temperature-sensitive.

[0011] Furthermore, this method allows for the one-step brazing of a complex component without the need for a furnace to braze the entire device, thanks to the brazing wire being placed inside the assembly of the two parts. This thus makes it advantageously suitable as a replacement for external laser-type welding solutions (which involve more steps in their process).

[0012] The wire thus enclosed in a groove or relief allows the reduction of the spreading of the brazed material during its melting, in particular of the "flux", outside the area to be brazed.

[0013] This brazing process is all the more advantageous as the brazing can be carried out vertically, horizontally, or at any other angle.

[0014] It is understood that "the room being at the level of the line of contact" means that a wall of the room is formed by the two rooms in contact with each other, so that the line of contact starts from said wall of the room.

[0015] According to one aspect of the invention, the cross-section of the brazing wire has a height between 1.2 and 2.3 mm.

[0016] By height of the wire we understand the height of the section in the direction of assembly of the two parts, that is to say in a direction perpendicular to the plane of the line of contact.

[0017] According to one aspect of the invention, the wire is placed in contact with the contact line,

[0018] According to one aspect of the invention, the height of the relief is between 0.5 mm and 1.2 mm mm.

[0019] According to one aspect of the invention, a wall of the chamber opposite a wall forming the brazing line has a viewing recess configured to allow visual verification of the presence of the wire from a point of view outside the assembly of the two parts.

[0020] According to one aspect of the invention, the viewing recess is present on only one side of the plane formed by the contact / brazing line.

[0021] According to one aspect of the invention, the viewing recess has a height at most equal to one of the parts of the wire, in particular to the part of the wire virtually crossed by the plane of the contact line and located on the side of the second part.

[0022] According to one aspect of the invention, the height of the chamber is greater than or equal to the height of the wire.

[0023] According to one aspect of the invention, the chamber has a width greater than the thickness of the wire, in particular by at least 0.15 mm, preferably at least 0.2 mm.

[0024] Advantageously, this lateral play allows for reliable assembly of the brazing wire in its chamber.

[0025] In addition, the width of the wire is less than the width of the chamber in which it is placed.

[0026] According to one aspect of the invention, the wire profile is slightly smaller in a radial direction than the profile of the chamber into which it is placed so as to be pressed in and held against the chamber profile. The wire is thus held as close as possible to the line of contact.

[0027] More specifically, when the wire forms a circular ring, the inner diameter of the ring is smaller than the outer diameter of the solder line so as to flare out when the ring is deposited in the chamber. This advantageously also provides a spring effect that holds the ring in the chamber.

[0028] According to one aspect of the invention, the wire has a circular, rectangular or oblong cross-section, preferably the shape is chosen from the rectangular or oblong shape, again preferably rectangular.

[0029] According to one aspect of the invention, at least one of the parts has a chamfer at the brazing line.

[0030] According to one aspect of the invention, only one of the parts has a chamfer at the brazing line.

[0031] According to one aspect of the invention, the weld line has a length equal to or greater than three times the minimum thickness of the part (E) of the first or second piece, preferably of the second piece, above the contact line and forming it.

[0032] The invention also relates to a fluidic connection element comprising two assembled parts brazed together by the induction brazing process as described herein.

[0033] The invention also relates to a thermal regulation device for an electronic and / or electrical component, such as an electrical storage module, comprising a fluidic connection element obtained from the induction brazing process as described herein.

[0034] The invention also relates to a thermal regulation assembly. This assembly can be intended to equip a vehicle, in particular a motor vehicle.

[0035] The control assembly comprises at least one electronic and / or electrical component, such as an electrical storage module, and at least one thermal control device for said at least one component as described above.

[0036] The invention may also relate to a battery pack comprising a plurality of energy storage cells and at least one thermal regulation device as defined above comprising a dielectric fluid circuit and at least a first group and a second group of dielectric fluid spray nozzles arranged to spray the plurality of energy storage cells.

[0037] In the present context, a module may be an energy storage cell. Alternatively, a module may comprise several energy storage cells. A module may also be defined as a container or housing comprising one or more electronic and / or electrical components.

[0038] Other advantages and features of the invention will become more apparent upon reading the following description, given by way of illustrative and non-limiting example, and the accompanying drawings, among which:

[0039] [Fig. 1] schematically illustrates, according to a first embodiment, an assembly of the two parts and the brazing wire before the latter is melted.

[0040] [Fig.2] schematically illustrates a detail according to a second embodiment before the melting stage, in which the second part is not visible, and in which the first part includes two brazing wires.

[0041] In these figures, identical elements bear the same reference numbers.

[0042] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features from different embodiments can also be combined or interchanged to provide other embodiments.

[0043] In the description, certain elements can be indexed, for example, first element or second element. In this case, it is a simple indexing to differentiate and to name similar but not identical elements. This indexing does not imply any priority of one element over another, and such names can easily be interchanged without departing from the scope of the present invention. Nor does this indexing imply any order in time.

[0044] Figure 1 schematically represents an embodiment of the process prior to the melting step of the brazing wire (6). The first part (1) has a raised section (4) in the form of a groove that accommodates the brazing wire (6) deposited there. The second part is then positioned, notably at the contact line (3), to form the chamber 5, which contains the wire (6). The contact line (3) extends along a plane P that virtually divides the wire (6) into two parts. In this example, the two parts are approximately equal, but they could represent between 40 and 60% of the cross-section of the wire (6).

[0045] It is understood that in the context of the invention, the contact line (3) forms the brazing line which will irreversibly join the two parts (1,2).

[0046] In this example, the two parts (1, 2) each include a chamfer in the area in contact with the wire and the contact line (3). This advantageously facilitates and improves the flow of the molten brazing wire into the contact line. Preferably, only one of the two parts includes the chamfer (8), in particular the part that is higher in the direction of gravity during brazing.

[0047] This process also advantageously allows brazing with better reliability of the parts without risking having too much material entering another area of ​​the parts (1,2) here the light (L) of the fluidic connection formed by the assembly of the two parts (1,2).

[0048] In certain embodiments as illustrated in [Fig. 1], a recess (7) is provided to allow verification of the presence of the brazing wire (6) before brazing. This recess (7) also allows verification of the actual melting of said wire (7) after induction heating.

[0049] Thanks to the relief (4) forming the chamber (5), the recess (7) allows easy visual control without risking that too much material will flow into the recess rather than into the contact line (3).

[0050] In certain embodiments not shown, the two parts (1, 2) comprise complementary structures configured to assemble reversibly in order to simplify the brazing process. Thus, once the wire (6) is inserted, the two parts (1, 2) are assembled so that they can be handled together for induction brazing.

[0051] The assembly can thus be the simple placement of one part on the other, or a reversible fixing, for example by clipping the parts together.

[0052] The presence of at least one chamfer advantageously promotes the capillary movement of the brazing wire metal as it melts. Preferably, the part with the chamfer is the highest part in the direction of gravity. In other words, the part above the plane of the brazing line is the part with the chamfer.

[0053] In [Fig.1] the wire (6) has a rectangular cross-section.

[0054] These shapes advantageously increase the contact area between the wire and the parts.

[0055] The wire (6) has a circular, rectangular or oblong cross-section, preferably the shape is chosen from the rectangular or oblong shape, again preferably rectangular.

[0056] By way of non-limiting example, [Fig.2] represents a first piece 2, which includes two reliefs (4) each of which includes a wire (6) allowing to braze to this first piece a second piece (2) or even a second and a third piece, each piece being brazed, simultaneously or one after the other, to the first piece (1).

[0057] The first part includes several recesses (7) in order to easily carry out visual verification on several different points of the area to be brazed and the brazing line.

[0058] In this [Fig.2], the first part (1) forms part of a collector of a thermal regulation device.

[0059] In other embodiments, the parts (1,2) form other elements requiring an irreversible connection.

[0060] In some embodiments, the two parts (1,2) are made of metal, in particular aluminum, in particular 3xxx or 6xxx series alloy aluminum.

[0061] The brazing wire is a continuous line of filler material whose melting temperature is lower than that of the materials constituting the first and second parts.

[0062] The brazing wire (6) can form a ring.

[0063] The wire can take any shape so as to follow the contour of the relief (4), for example of the groove, of at least the first piece (1).

[0064] Thus, in [Fig.2], a first wire (6) has a circular shape, while the other has a different shape, here a “D” shape.

[0065] In some embodiments, the brazing wire (6) is made of metal, preferably 4xxx series aluminum such as 4343, 4045 or 4047, preferably 4047, also called AlSil2.

Claims

Demands

1. A method for induction brazing a first part (1) with a second part (2) at a contact line (3) at which the two parts are in contact for brazing, whereby at least the first part (1), in particular the two parts (1, 2), has a relief (4), in particular a groove, which forms a chamber (5) when the first part is brought into contact with the second part for brazing, said chamber being at the contact line, the brazing method comprising the following steps: - Depositing a brazing wire (6) in said chamber formed by said relief of the at least first part (1), - Closing the chamber by joining the second part (2) with the first part (1); - Heating at least the brazing wire by induction heating so as to melt it;The process being characterized in that the brazing wire (6) is arranged in said chamber (5) at the level of the contact line (3) so that said contact line forms a plane (P) which virtually cuts the brazing wire (6) into two parts, each part representing between 40% and 60% of the total cross-section of the brazing wire (6), in particular between 45% and 55%.

2. Method according to the preceding claim, wherein the cross-section of the brazing wire (6) has a height between 1.2 and 2.3 mm.

3. A method according to any one of the preceding claims, wherein the wire (6) is placed in contact with the contact line (3),

4. A method according to any one of the preceding claims, wherein the height of the relief (4) is between 0.5 mm and 1.2 mm.

5. A method according to any one of the preceding claims, wherein a wall of the chamber (5) opposite a wall forming the brazing line has a viewing recess (7) configured to allow visual verification of the presence of the wire from a point of view outside the assembly of the two parts.

6. Method according to the preceding claim, wherein the viewing recess (7) is present on only one side of the plane formed by the contact / brazing line (3).

7. A method according to the preceding claim, wherein the viewing recess (7) has a height at most equal to one of the parts of the wire (6), in particular to the part of the wire (6) virtually crossed by the plane of the contact line (3) and located on the side of the second part (2).

8. A method according to any one of the preceding claims, wherein the height of the chamber (5) is greater than or equal to the height of the wire (6).

9. A method according to any one of the preceding claims, wherein the chamber (5) has a width greater than the thickness of the wire (6), in particular of at least 0.15 mm, preferably at least 0.2 mm.

10. A method according to any one of the preceding claims, wherein the wire (6) has a circular, rectangular or oblong cross-section, preferably the shape is chosen from the rectangular or oblong shape, again preferably rectangular.

11. A method according to any one of the preceding claims, wherein at least one of the parts has a chamfer (8) at the brazing line.

12. A method according to any one of the preceding claims, wherein only one of the parts (1,2) has a chamfer (8) at the level of the brazing line (3).

13. A method according to any one of the preceding claims, wherein the weld line (3) has a length equal to or greater than three times the minimum thickness of the portion (E) of the first (1) or second piece (2), preferably of the second piece (2), above the contact line (3) and forming it.

14. Fluidic connection forming element (10) comprising two assembled parts brazed together by the induction brazing process according to one of the preceding claims.

15. Thermal regulation device for an electronic and / or electrical component comprising a fluidic connection element (10) obtained from the induction brazing process according to the preceding claim.