METHOD FOR CONTROLLING DEFORMATIONS OF A PART INDUCED BY ADDITIVE METALLIC MANUFACTURING

Abstract

METHOD FOR CONTROLLING DEFORMATIONS OF A PART INDUCED BY ADDITIVE METAL MANUFACTURING The present invention relates to a method for controlling deformations induced by the temperature rise of a part (6) during the addition of reinforcing material (8) by additive manufacturing on a first face (6.1) of said part, notable in that said method comprises heating the part through a second face (6.2) opposite the first face, by means of a device (2) according to the invention, so as to compensate for the future deformations of the part generated by the subsequent temperature rise during the addition of reinforcing material. (Figure to be published with the abbreviation: Figure 2)

Description

Title of the invention: METHOD FOR CONTROLLING DEFORMATIONS OF A PART INDUCED BY ADDITIVE METAL MANUFACTURING Technical field

[0001] The present invention relates to the field of motor vehicles, more particularly to the field of reinforced parts by additive manufacturing for motor vehicles. Previous technique

[0002] Conventionally, several methods exist for reinforcing a part that has been previously formed and shaped by stamping, bending, etc. A common practice is to weld or, using 3D printing, apply a reinforcing element to a specific area of ​​the part. This additive manufacturing reinforcement process aims to optimize the amount of material added to the base part in an overall quest to reduce the weight of mechanical parts, particularly for automotive structures.

[0003] Such a process is implemented by melting, for example, a metal powder or a metal wire using the so-called DED "Directed Energy Deposition" technique, which uses a laser, or WAAM "Wire Arc Additive Manufacturing", which uses an electric arc.

[0004] However, adding material by 3D printing leads to a significant increase in temperature on the base part. This temperature rise, unavoidable and inherent to the choice of process, can cause deformation of the part after its reinforcement, which is detrimental to the assembly operations of said part with other surrounding components, resulting in assembly non-conformities.

[0005] The patent document published FR 3 124 099 Al proposes to create on one face an excess thickness of material intended to compensate for future deformations caused by the temperature rise of a part during a 3D printing on an opposite face of said part.

[0006] However, the solution proposed by the document has room for improvement, in particular to provide more precision in maintaining the initial shape of the part before its deformation due to the rise in temperature. Description of the invention

[0007] The present invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More specifically, the invention aims to to offer a simple, efficient and economical solution to avoid deformation of mechanical parts when adding reinforcing metal by additive manufacturing.

[0008] To this end, the invention relates to a device for holding a part during the addition of reinforcing material by additive manufacturing on a first face of said part, remarkable in that said device comprises a body having a receiving face intended to be in direct contact with a second face opposite to the first face of the part, said body further comprising at least one heating means capable of heating the part through the second face, so as to compensate for potential deformations of the part induced by a subsequent rise in temperature during the addition of reinforcing material.

[0009] According to one embodiment, at least one heating means comprises at least one electric heating resistance capable of rising to a temperature of up to 800°C.

[0010] According to one embodiment, at least one heating means comprises at least two electric heating resistors inserted into corresponding orifices opening onto a lateral face of the body of said device.

[0011] Preferably, at least one electrical resistance is combined with a thermocouple in the corresponding orifice.

[0012] The invention also relates to a method for controlling deformations induced by the temperature rise of a part during the addition of reinforcing material by additive manufacturing on a first face of said part, remarkable in that said method includes heating the part through a second face opposite to the first face, so as to compensate for future deformations of the part generated by the subsequent temperature rise during the addition of reinforcing material.

[0013] According to one embodiment, during additive manufacturing, the second face is heated to a temperature of at least 100°C.

[0014] According to one embodiment, additive manufacturing includes a WAAM technique for electric arc deposition of a metal wire, or a DED technique for powder bed fusion or metal wire deposition using a laser.

[0015] According to one embodiment, the heating of the room through the second face is carried out by means of the device according to the invention.

[0016] The invention also relates to a reinforced part remarkable in that it is obtained by means of a process according to the invention.

[0017] According to one embodiment, said part comprises a thin thickness of between 1 mm and 4 mm. Preferably, the part is made from sheet metal.

[0018] The invention also relates to a motor vehicle comprising at least one part according to the invention.

[0019] The measures of the invention are advantageous in that targeted heating of the second face of the part significantly limits the temperature gradient between the first and second faces, thereby effectively and precisely preventing potential deformations of the part induced by a subsequent temperature rise during the application of reinforcing material to the first face. Brief description of the drawings

[0020] [Fig-1] represents a perspective view of a device according to the invention, for holding a part during the addition of reinforcing material by additive manufacturing;

[0021] [Fig.2] represents a perspective view of the device of [Fig.1] receiving the part during additive manufacturing, said part being heated through a second face opposite to that comprising the reinforcement, so as to compensate for potential deformations of the part induced by a subsequent temperature rise. Detailed description

[0022] Fig. 1 represents a perspective view of a device 2 according to the invention, for holding a part (visible in Fig. 2) during the addition of reinforcing material by additive manufacturing.

[0023] The device 2 preferably comprises a body 4 having a receiving face 4.1 intended to be in direct contact with the part.

[0024] With reference to figures 1 and 2, the receiving face 4.1 is in direct contact with a second face 6.2 of the part 6 located opposite a first face 6.1 receiving a metallic reinforcement 8 printed in 3D, preferably by a DED technique of powder bed fusion or on metal wire using a laser, and more preferably by a WAAM technique of electric arc deposition of a metal wire.

[0025] Since the printing of the reinforcement 8 is carried out at ambient temperatures, the melting temperatures of the printing filaments generate significant temperature gradients present locally between the printing area on the first face 6.1 and the other opposite area at the level of the second face 6.2 not receiving printing.

[0026] The inventors have observed that the more pronounced the gradients, the greater the risk of deformation of the parts 6, after the 3D printing of the reinforcement 8, due to the high stresses on the part 6.

[0027] Advantageously, the body 4 includes at least one heating means 10 suitable for heating the part 6 through the second face 6.2, so as to compensate for potential deformations of the part 6 induced by a subsequent temperature rise during the addition of reinforcing material 8.

[0028] The heating of part 6 from the second face 6.2 is carried out during and / or before 3D printing, preferably at a temperature of at least 100°C and at most 800°C, and more preferably between 100°C and 300°C, and even more preferably between 150°C and 250°C. Advantageously, such heating makes it possible to considerably limit the temperature gradient between the two faces 6.1 and 6.2, which makes it possible to effectively and selectively prevent deformation of part 6.

[0029] In this regard, the body 4 preferably comprises heating means 10 including heating electric resistances 10 inserted into corresponding orifices 12 which open onto a lateral face 4.2 of the body 4 of the device 4. The resistances 10 include cables 10.1 which have been partially illustrated in figures 1 and 2.

[0030] Preferably, the body comprises four electrical resistances 10 arranged in the body 4 close to the receiving face 4.1, this optimizes the time required for the temperature rise of the second face 6.2. For example, the resistances 10 can be arranged at about one-third of a thickness E of the body 4.

[0031] The body 4, and in particular its receiving face 4.1, can be obtained graphically, which allows for better heat retention and distribution towards the part 6.

[0032] Preferably, each resistance 10 is coupled to a corresponding thermocouple allowing the instantaneous temperature to be measured. This can enable monitoring of the process, for example, through a human-machine interface, and can also enable automated control of the temperature rise according to the 3D printing, in particular to automatically manage the heating of the part 6 in order to guarantee homogeneity of the temperature rise according to the extent of the part 6 and / or the reinforcement 8.

[0033] The resistors 10 can be of a straight cylindrical shape extending in the body 4 substantially transversely to the reinforcement 8, or can alternatively extend so as to follow the shape of the reinforcement 8 on the first face 6.1.

[0034] Advantageously, the reinforced part 6 is made of thin sheet metal having a thickness between 1 and 4 mm, and more preferably between 1 and 3 mm.

[0035] The ribbed reinforced part 6, heated during the 3D printing operation of the rib 8, will not undergo any deformation and can thus be subsequently integrated with other parts in the same tooling as the part not having received reinforcement by 3D printing, with a view to their assembly on the same motor vehicle.

[0036] This makes it possible to obtain a variety of parts with or without reinforcement (depending on the vehicle variant) without having to use multiple tooling later in the process assembly, because the two parts (with or without reinforcement) will have absolutely the same geometry, without any deformation, and this, thanks to the present invention.

Claims

Demands

1. Device (2) for holding a part (6) during the addition of reinforcing material (8) by additive manufacturing on a first face (6.1) of said part (6), characterized in that said device (2) comprises a body (4) having a receiving face (6.1) intended to be in direct contact with a second face (6.2) opposite the first face (6.1) of the part (6), said body (4) further comprising at least one heating means (10) capable of heating the part (6) through the second face (6.2), so as to compensate for potential deformations of the part (6) induced by a subsequent temperature rise during the addition of reinforcing material (8).

2. Device (2) according to claim 1, wherein at least one heating means (10) comprises at least one electric heating resistance (10) capable of rising to a temperature of up to 800°C.

3. Device (2) according to any one of claims 1 and 2, wherein at least one heating means (10) comprises at least two electric heating resistors (10) inserted into corresponding orifices (12) opening onto a lateral face (4.2) of the body (4) of said device (2).

4. A method for controlling deformations induced by the temperature rise of a part (6) during the addition of reinforcing material (8) by additive manufacturing on a first face (6.1) of said part (6), characterized in that said method comprises heating the part through a second face (6.2) opposite to the first face (6.1), so as to compensate for future deformations of the part (6) generated by the subsequent temperature rise during the addition of reinforcing material (8).

5. A method according to claim 4, wherein during additive manufacturing, the second face (6.2) is heated to a temperature of at least 100°C.

6. A method according to any one of claims 4 and 5, wherein the additive manufacturing comprises a WAAM deposition technique

7.

8.

9.

10. by electric arc of a metal wire, or a DED technique of powder bed fusion deposition or metal wire using a laser. A method according to any one of claims 4 to 6, wherein the heating of the part through the second face (6.2) is carried out by means of the device (2) according to any one of claims 1 to 3. Reinforced part (6) for motor vehicle, characterized in that it is obtained by means of a process according to any one of claims 4 to 7. Part (6) according to claim 8, wherein said part (6) comprises a thin thickness of between 1 mm and 4 mm. Motor vehicle comprising at least one part (6) according to one of claims 8 and 9.

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