Method for assembly by brazing and product resulting from the method

Abstract

The invention relates to a method for induction brazing of a first part (1) with a second part (2) at a contact line (3), wherein at least the first part (1) has a raised portion (4), which forms a chamber (5), the chamber being at the contact line, comprising the following steps: - depositing a brazing wire (6) in the chamber; - closing the chamber by assembling the second part (2) with the first part; - heating at least the brazing wire by induction so as to melt it; the contact line forming a plane (P) that virtually divides the brazing wire (6) into two portions, each portion representing 40% to 60% of the entire cross-section of the brazing wire.

Description

Description Title: Brazing assembly process 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 with a high melting point, especially metal parts, allowing the use of a brazing wire with a lower melting point.

[0003] The electrical and / or electronic components that may be relevant to the present invention may include electrical energy storage elements, particularly 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 can be unreliable, damaging or even destroying one of the parts. Furthermore, for large production volumes, such a process can be costly and / or time-consuming.

[0006] In prior art, a solution was 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 it to bond the assembly.

[0007] One disadvantage of this solution is that brazing the entire part requires large furnaces, sized according to the dimensions of the parts to be assembled. Another disadvantage is the energy cost of such a process, resulting 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 a localized induction brazing process, which allows to do without large traditional brazing furnaces and therefore 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 assembled 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 part is brought into contact with the second part to be brazed, said chamber being at the level of the contact line, the brazing method comprising the following steps: - Deposition of a brazing wire in said chamber formed by said relief of F in at least the first piece, - Closing the chamber by assembling the second piece with the first piece; - Heating 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 allows for a more efficient and precise localized brazing process, enabling the assembly of several parts, some of which may be temperature-sensitive.

[0011] Furthermore, this process allows for the single-step brazing of a complex component without the need for a furnace to braze the entire assembly, thanks to the brazing wire being placed inside the joint between the two parts. This makes it a superior alternative to 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 the "flux", outside the area to be brazed.

[0013] This brazing process is all the more advantageous because 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] The height of the wire is understood to be the height of the section in the direction of assembly of the two pieces, 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.

[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] Furthermore, 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 that it is 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 ring's internal diameter is smaller than the external diameter of the solder line, causing it to flare out when the ring is deposited in the chamber. This advantageously creates a spring effect that holds the ring in place.

[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 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 system. This system can be intended for use in a vehicle, particularly a car.

[0035] The control assembly includes 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 this context, a module can be a single energy storage cell. Alternatively, a module can comprise multiple energy storage cells. A module can also be defined as a container or housing containing one or more electronic and / or electrical components.

[0038] Other advantages and features of the invention will become clearer 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 casting stage, in which the second piece is not visible, and in which the first piece 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 simply indexing to differentiate and name similar but not identical elements. This indexing does not imply The priority of one element over another is established, and such designations can easily be interchanged without departing from the scope of the present invention. This indexing also does not imply any temporal order.

[0044] Figure 1 schematically represents one embodiment of the process before the solder wire (6) melting step. The first part (1) has a raised groove (4) that accommodates the solder wire (6) deposited within it. The second part is then positioned, notably at the contact line (3), to form the chamber (5) that 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 wire's cross-section.

[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, both parts (1, 2) each have a chamfer at the point of 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 has the chamfer (8), specifically 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 Figure 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 too much material flowing into the recess rather than into the contact line (3).

[0050] In some unillustrated embodiments, the two parts (1, 2) comprise complementary structures configured to assemble reversibly from 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 the purpose of induction brazing.

[0051] The assembly can therefore be the simple placement of one part on top of another, 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 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 figure 1 the wire (6) has a rectangular cross-section.

[0054] These shapes advantageously increase the contact surface 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, figure 2 represents a first piece 2, which includes two reliefs (4) which each include 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 perform visual verification on several different points of the area to be brazed and the brazing line.

[0058] In this figure 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 figure 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 aluminium such as 4343, 4045 or 4047, preferably 4047, also called AlSil2.

Claims

Demands

1. Induction brazing method of a first part (1) with a second part (2) at a contact line (3) at which the two parts are in contact for brazing, at least the first part (1), in particular the two parts (1, 2), having 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: - Deposition of a brazing wire (6) in said chamber formed by said relief of F at least first piece (1), - Closing the chamber by assembling the second piece (2) with the first piece (1); - Heat 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.

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