阅读说明：本技术 用于通过金属沉积进行三维打印的装置 (Device for three-dimensional printing by metal deposition ) 是由 特伦斯·格雷尔 塞德里克·皮埃尔·雅克·科拉斯 雨果·西斯塔赫 于 2020-02-12 设计创作，主要内容包括：本发明公开了用于通过金属沉积进行三维打印的装置(10b),包括用于在惰性气氛下将金属丝(18)引导到外壳(12)中的引导管(16b),其特征在于,该装置包括注入设备(30),用将惰性气体(32)注入到引导管(16b)中,所述注入设备(30)包括惰性气体供应管道(36),其下游端(362)通向导管(16b),并且其上游端(361)连接惰性气体供应设备(34),引导管(16b)基本上是直的,在通向引导管(16b)的惰性气体供应管道(36)的出口处,惰性气体供应管道(36)的下游端(362)在与引导管的延伸方向(X)形成严格地小于90°的方向延伸。惰性气体供应管道的布置限制了将空气引入到外壳的惰性空气中。(The invention discloses an apparatus (10b) for three-dimensional printing by metal deposition, comprising a guide tube (16b) for guiding a wire (18) into a housing (12) under an inert atmosphere, characterized in that it comprises an injection device (30) for injecting an inert gas (32) into the guide tube (16b), said injection device (30) comprising an inert gas supply duct (36) whose downstream end (362) opens into the guide tube (16b) and whose upstream end (361) is connected to an inert gas supply device (34), the guide tube (16b) being substantially straight, the downstream end (362) of the inert gas supply duct (36) extending at an outlet of the inert gas supply duct (36) opening into the guide tube (16b) in a direction forming a direction strictly less than 90 DEG with the extension direction (X) of the guide tube. The arrangement of the inert gas supply pipe restricts the introduction of air into the inert air of the housing.)

1. An apparatus (10b) for three-dimensional printing by metal deposition, comprising a guide tube (16b) for guiding a wire (18) into a housing (12) under an inert atmosphere, characterized in that it comprises an injection device (30) for injecting an inert gas (32) into the guide tube (16b), said injection device (30) comprising an inert gas supply duct (36) whose downstream end (362) opens into the guide tube (16b) and whose upstream end (361) is connected to an inert gas supply device (34), the guide tube (16b) being substantially straight, the downstream end (362) of the inert gas supply duct (36) extending at the outlet of the inert gas supply duct (36) opening into the guide tube (16b) in a direction forming strictly less than 90 ° with the direction of extension (X) of the guide tube.

2. The apparatus (10b) for three-dimensional printing by metal deposition according to claim 1, wherein the injection device (30) is configured to inject an inert gas (32) at a flow rate between 2 bar and 6 bar.

3. The device (10b) for three-dimensional printing by metal deposition according to claim 1, wherein the inert gas (32) is argon or nitrogen.

4. Device (10b) for three-dimensional printing by metal deposition according to one of claims 1 to 3, comprising a heating device able to melt the metal wire.

5. The apparatus (10b) for three-dimensional printing by metal deposition according to claim 4, wherein the apparatus comprises a head having a heating device arranged around a wire guide tube (16).

6. Apparatus (10b) for three-dimensional printing by metal deposition according to claim 4, wherein said heating means comprise one or more devices (22b) for emitting laser beams converging at a given application point of said wire (18).

Technical Field

The present invention relates to the field of three-dimensional printing devices, and more particularly to devices for three-dimensional printing by metal deposition.

Background

Three-dimensional printing using the so-called LMD (laser metal deposition) process involves the successive deposition of thin layers of molten metal.

Figure 1 shows an LMD printing apparatus 10a of known type comprising a housing 12 under an inert atmosphere, a head 14a having a longitudinal guide tube 16a for guiding a wire 18. Head 14a opens into housing 12 and has an elongated tubular body with a distal end 20a connected to wire 18 outlet nozzle. A guide tube 16a of wire 18 is mounted in the elongate tubular body of head 14 a. The guide tube 16a includes a distal end portion 20a that forms an outlet nozzle for the wire 18.

The wire 18 exiting the head 14a is heated by a heating device 22 carried by the head 14 a. These heating devices include a laser that is oriented to melt the wire 18 exiting the catheter. These heating means comprise means 22b for emitting one or more high temperature laser beams which impinge on and melt the wire 18.

During operation, the wire 18 is inserted at the proximal end 20b of the guide tube 16a and moves within and along the guide tube 16 a. An annular gap must be provided between the inner annular surface of guide tube 16a and the outer annular surface of wire 18 to allow it to move to the distal end 20a of guide tube 16 a. Once the wire has exited the nozzle, it is heated by a heating device 22. This heating is performed by a laser beam at a distance from the outlet nozzle, melting the wire 18. The wire in the molten state is continuously applied to the substrate 24 or one of the thin layers 26 of molten metal previously applied to form the desired three-dimensional portion.

Such a printing process causes difficulties associated with introducing the outside air 28 into the housing 12 through the guide duct 16 a.

In particular, the difficulty relates to introducing a flow of outside air 28 into the guide tube 16 from outside the guide tube, which is then discharged into the housing 12 through an outlet nozzle. This air 28 contaminates the enclosure 12 under an inert atmosphere and oxidizes the thin layer 26 of molten metal that is superimposed on the thin layer 26 of molten metal to make the part to be printed.

In response to the above-described problems of the prior art, the present invention is directed to realizing a three-dimensional printing apparatus.

Disclosure of Invention

Accordingly, the present document relates to an apparatus for three-dimensional printing by metal deposition, comprising a guide tube for guiding a wire to a housing under an inert atmosphere, characterized in that the apparatus comprises an injection device for injecting an inert gas into the guide tube. The presence of the device for injecting inert gas into the wire guide tube makes it possible to create an overpressure in the guide tube and to prevent the external air introduced into the guide tube from reaching the distal end of the guide tube through which the wire exits. This overpressure generated in the guide tube thus prevents external air from entering the enclosure under an inert atmosphere and from oxidizing the thin layer of molten metal deposited on the substrate or other previously deposited thin layers of molten metal.

The injection device may comprise an inert gas supply conduit, the downstream end of which opens into the guide tube and the upstream end of which is connected to the inert gas supply device.

The inert gas injection apparatus includes an inert gas supply conduit in fluid communication with the wire guide tube and with an inert gas supply apparatus that supplies the inert gas supply conduit at an upstream end. The inert gas flows through the supply conduit until it emerges at the downstream end of the guide tube.

The guide tube may be substantially straight. The inert gas supply pipe may open at its downstream end in a direction substantially perpendicular to the guide pipe.

More generally, the guide tube may be substantially straight, the downstream end of the inert gas supply duct extending in a direction forming an angle of less than or equal to 90 ° with the direction of extension of the guide tube at the inert gas supply duct outlet leading to the guide tube. Thus, the inflow of the external air into the guide pipe is more easily prevented by the relatively small inert gas flow.

The angle may be included between a first straight portion of the guide tube extending from the distal end of the guide tube to an inert gas supply tube outlet opening to the guide tube and a second straight portion of the inert gas supply tube joining the inert gas supply tube outlet to the guide tube.

The orientation of the inert gas supply pipe outlet may create an overpressure in the wire guide tube, thereby preventing the flow of outside air introduced into the wire guide tube. In this way, the wire guide tube is free of oxygen-enriched air between the overpressure generated and its distal end, i.e. inside the housing. This arrangement of the inert gas supply pipe restricts the introduction of air into the inert air of the casing.

Further, in order to further prevent the introduction of the outside air, it may be desirable that the above-mentioned angle is strictly less than 90 °. In this way, the air flow from the supply duct is mostly directed towards the end of the guide duct leading to the outside of the housing.

The injection device may be configured to inject the inert gas at a flow rate between 2 bar and 6 bar.

An inert gas flow between 2 bar and 6 bar creates an overpressure and prevents the movement of external air in the wire guide tube.

The inert gas may be argon or nitrogen. The gas avoids any reaction with the parts and/or the deposited material and therefore any contamination associated with the external atmosphere.

The apparatus may still include a heating device capable of melting the wire.

These heating devices may be housed in a head comprising a heating device arranged around the wire guide tube.

The heating means may comprise one or more means for emitting a laser beam which converges at a given point of application of the wire.

The head supporting the heating device may be structurally separate from the wire guide tube.

The invention will be better understood and other details, features and advantages thereof will appear, when the following description is given, by way of non-limiting example, with reference to the accompanying drawings.

Drawings

Figure 1 is a schematic view of a three-dimensional printing apparatus according to the prior art described above,

fig. 2 is a schematic diagram of a three-dimensional printing apparatus according to one embodiment described in the specification.

Fig. 3 is a schematic view showing a device of a modification of fig. 2.

Fig. 4 is a schematic view showing a device of still another modification.

Detailed Description

The apparatus 10b for three-dimensional printing according to the present invention includes: a housing 12 under an inert atmosphere, a device 30 for injecting an inert gas 32, and a head 14b, the head 14b comprising a guide tube 16b for guiding the wire 18. The head 14b opens into the housing 12 and has an elongate tubular body in which is mounted a tubular conduit 16b for guiding a wire 18. The head 14b, and more specifically the guide tube 16b housed within the head 14b, has a distal end 20b connected to the wire outlet nozzle.

The inert gas 32 injection apparatus 30 includes an inert gas supply conduit 36 connected to a supply apparatus 34. The inert gas 32 enters the supply conduit 36 from an upstream end 361 of the conduit to which the supply device is connected and is discharged from a downstream end 362 of the supply conduit to the wire guide tube 16 b.

The wire guide tube 16b is substantially straight and extends in the extension direction X. The inert gas supply pipe 36 opens at its downstream end 362 in a direction substantially perpendicular to the extending direction X of the wire guide 16 b.

The injection device 30 is configured to inject an inert gas 32 at a flow rate between 2 bar and 6 bar.

When the inert gas 32 is injected into the inert gas supply conduit 36 at a flow rate of between 2 bar and 6 bar, the inert gas 32 introduced into the wire guide tube 16b creates an overpressure in the wire guide tube. The overpressure created by the injection of inert gas 32 prevents outside air 28 that has entered guide tube 16b from moving beyond the overpressure. Thus, the wire guide tube 16b has an oxygen-free fluid between the overpressure and the distal end 20b of the guide tube 16 b.

In a particular embodiment, the head 14b has a through-hole (not shown) between the area of the guide tube 16b subjected to overpressure and the wire outlet nozzle. The through hole allows the guide tube 16b to be in fluid communication with the housing.

Reference is now made to fig. 3, which fig. 3 is a variation of the embodiment shown in fig. 2. It differs from this previous embodiment in that the inert gas supply conduit is not oriented at 90 ° relative to the wire guide tube. In practice, it can be observed that the downstream end 362 of the inert gas supply duct 38 opens in the direction D, at the outlet of the inert gas supply duct leading to the guide tube, at its downstream end forming an angle of less than 90 ° with the extension direction X of the guide tube. Such an orientation of less than 90 ° may facilitate the inert gas flow to be directed toward an end of the guide tube, which is opposite to the direction disposed inside the housing 30.

The embodiment in fig. 4 shows another embodiment in which the guide tube 16c is structurally different from the head 14b with the heating device 22 b. Thus, it can be seen that the flow guide tube is not mounted in the elongate tubular body as in the embodiment of figure 1.