FR3066413A1 - ENCLOSURE FOR CONTAINING A MACHINE OPERATING IN A GASEOUS ENVIRONMENT CONTROL AND METHOD FOR CREATING THE GASEOUS ENVIRONMENT CONTROL - Google Patents

Abstract

The invention relates to an enclosure (1) intended to contain a machine (M) or a working zone requiring a controlled gaseous environment composed of at least one controlled gas (G), said enclosure comprising a feed circuit (3) in controlled gas (G), a closed space (4) of variable volume in which the supply circuit injects the controlled gas. The invention also relates to a method for creating a controlled gaseous environment composed of at least one controlled gas (G) in a chamber (1) according to the invention, the method comprising a gas injection step controlled simultaneously with the increase in the volume of the closed space.

Description

ENCLOSURE FOR CONTAINING A MACHINE OPERATING IN

A CONTROLLED GASEOUS ENVIRONMENT AND METHOD FOR CREATING

THE GASEOUS ENVIRONMENT CONTROLS

1. Field of the invention

The invention relates to the field of enclosures intended to contain a machine operating in a controlled gaseous environment. The invention relates more particularly to such an enclosure, a machine equipped with such an enclosure and a process for creating the controlled gaseous environment.

2. Prior art

The manufacture of parts for example by additive printing conventionally requires operating in a controlled gaseous environment in order to avoid degradation of the part during the manufacturing process due to phenomena such as oxidation. The controlled gaseous environment is composed of a controlled gas such as an inert gas.

At present, several methods exist for obtaining the controlled gaseous environment near the working area of a machine intended to manufacture such parts. A first method consists in injecting the gas controlled by a nozzle present on the machine at a point in this zone. The area has no physical border. Therefore, the quality of the gaseous environment suffers from the fact that unwanted gases can enter the work area.

Other methods consist in creating a controlled gaseous environment in a closed enclosure. However, the expulsion of the atmosphere initially contained in the closed enclosure is delicate. Thus, unwanted gas residues often remain in the enclosure and the improvement of the quality of the gaseous environment controlled by filtering for example requires a significant treatment time which is all the longer the larger the enclosure. .

3. Objectives of the invention

The invention proposes a solution aimed at overcoming the aforementioned drawbacks. An objective of the invention is to allow the rapid creation of a gaseous environment of controlled quality in an enclosure.

4. Summary of the invention

The invention relates to an enclosure intended to contain a machine or a work area requiring a controlled gaseous environment composed of at least one controlled gas, said enclosure comprising a controlled gas supply circuit and a closed space with variable volume in which the supply circuit injects the controlled gas. The invention makes it possible to quickly obtain a gaseous controlled environment of very good quality for machines which can have large volumes in an enclosure having a light structure, not very robust, insofar as the variability of the volume of the closed space makes it possible to maintain the pressure in the enclosure at a level comparable to atmospheric pressure, which limits the forces exerted on the walls of the enclosure.

According to a particular embodiment of the invention, the enclosure comprises a purge circuit arranged to evacuate the gaseous environment contained in the closed space. The purge circuit allows the evacuation of unwanted gases in the controlled gas environment. In particular, the purge circuit makes it possible to create a vacuum before injecting the controlled gas.

According to a particular embodiment of the invention, the closed space is delimited at least in part by a deformable envelope. The deformability of the envelope can be obtained in different ways, for example by using an envelope composed of several rigid articulated portions or by using a flexible envelope. The flexible envelope can be elastically deformable or not.

According to a particular embodiment of the invention, the deformable envelope is inflatable. An inflatable envelope makes it possible to obtain the deformable character in a simple, compact and economical manner.

According to a particular embodiment of the invention, the enclosure comprises an inflation circuit arranged to inflate the deformable envelope. The inflation circuit can possibly be used to inflate other parts of the enclosure. The inflation circuit may optionally be the controlled gas supply circuit.

According to a particular embodiment of the invention, the deformable envelope forms at least one pocket in the enclosure, the increase in the volume of the pocket reducing the volume of the closed space and vice versa. The bags can be integrated into the working environment of the machine so as to adapt to existing manufacturing premises. For example, the pockets can be integrated into a closed room of a manufacturing hangar.

According to a particular embodiment of the invention, the deformable envelope comprises at least one portion also delimiting the enclosure. An enclosure comprising such a deformable envelope has the advantage of being able to pass from a deployed position to a retracted position, thereby reducing the size of the enclosure when the deployed position is not necessary. Furthermore, such enclosures may have light structures, inexpensive to manufacture and adapting the closed space to the size of the machine so as to limit the amount of controlled gas required. Such enclosures also make it possible to limit the size of the closed space to the necessary volume and thus to save the controlled gas.

According to a particular embodiment of the invention, the enclosure includes a gas seal with the ground. An enclosure comprising a seal with the ground makes it easier to move the machine in order to place it in the closed space. Indeed, to place the machine in the closed space of the enclosure, the enclosure is lifted, moved and placed on the ground so as to encompass the machine.

According to a particular embodiment of the invention, the seal is produced by an inflatable element. Such a seal is simple to install and economical. It can be made of materials comparable to those used for the deformable envelope.

According to a particular embodiment of the invention, the seal comprises at least one portion of lip seal made of polytetrafluoroethylene.

According to a particular embodiment of the invention, the enclosure has the shape of a deformable bell or tunnel. Such forms make it possible to limit the trapping of undesirable gas in corners.

According to a particular embodiment of the invention, the enclosure comprises an airlock at the interface between an access to the closed space and the outside of the closed space. The airlock makes it possible to guarantee the maintenance of the quality of the controlled environment in the closed space and to limit leaks while having access to the closed space.

According to a particular embodiment of the invention, the enclosure comprises a recycling circuit connecting the purge circuit and the supply circuit and arranged to reinject gas into the enclosure after having previously taken it from the enclosure and filtered . The recycling circuit makes it possible to maintain an important quality of the controlled gaseous environment while limiting the wastage of controlled gas.

According to a particular embodiment of the invention, the supply circuit comprises a source of controlled gas, a supply pressure sensor, and at least one supply valve.

According to a particular embodiment of the invention, the purge circuit comprises a purge valve, a purge pressure sensor, a negative pressure pump, a gas analyzer, and a non-return valve.

According to a particular embodiment of the invention, the inflation circuit comprises a source of inflation gas, a positive and negative pressure pump, an inflation valve, an inflation pressure sensor, and a nozzle for diffusing the inflation gas. in the envelope.

According to a particular embodiment of the invention, the recycling circuit includes a switch valve from the purge circuit, and a filter suitable for the controlled gas.

According to a particular embodiment of the invention, the enclosure further comprises a fan arranged to stir the controlled gaseous environment.

According to a particular embodiment of the invention, the closed space comprises a motorized structure arranged to vary the volume of the closed space.

According to a particular embodiment of the invention, the enclosure further comprises a gas cooling system integrated into the supply circuit and / or the recycling circuit and / or into a wall of the enclosure. The cooling system is for example a network of conduits in which circulates a cooling liquid such as water.

The invention also relates to a machine intended to operate in a controlled gaseous environment composed of at least one controlled gas, said machine comprising a controlled gas supply circuit and an enclosure comprising a closed space of variable volume in which the circuit d supply injects controlled gas. The machine then has an integrated nozzle for injecting the controlled gas in the immediate vicinity of the working area.

The enclosure according to different variants includes one or the other of the characteristics listed in the particular embodiments of the invention above.

The invention also relates to a method for creating a controlled gaseous environment composed of at least one controlled gas in an enclosure intended to contain a machine or a work area requiring the controlled gaseous environment, the enclosure comprising a closed space. variable volume and a controlled gas supply circuit, the method comprising a step of injecting controlled gas simultaneously with increasing the volume of the closed space. The invention makes it possible to quickly obtain a gaseous controlled environment of very good quality for machines which can have large volumes in an enclosure having a light structure, not very robust, insofar as the variability of the volume of the closed space makes it possible to maintain the pressure in the enclosure at a level comparable to atmospheric pressure, which limits the forces exerted on the walls of the enclosure.

According to a particular embodiment of the invention, the enclosure further comprising a purge circuit, the method comprises, before the step of injecting controlled gas, a step of purging the gas contained in the closed space simultaneously with the reduction of the volume of the closed space. Reducing the volume of the closed space simultaneously with the purging of the gas contained in the space makes it possible to limit the vacuum in the enclosure and therefore the forces exerted on the walls. Furthermore, the reduction in the volume of the closed space increases the efficiency of the purge insofar as the reduction in the volume of the closed space helps to expel the gas.

According to a particular embodiment of the invention, the volume of the closed space is increased by increasing the volume of the enclosure. Such a method is implemented for example in an enclosure comprising a deformable envelope of which at least a portion also delimits the enclosure.

According to a particular embodiment of the invention, the enclosure comprising at least one inflatable deformable envelope forming a pocket inside the enclosure, the reduction of the volume of the closed space is achieved by inflating the deformable envelope. Such a method makes it possible to create a controlled gaseous environment in the existing workspace without creating a new structure or a new enclosure but by adapting the existing one, provided that the workspace can be hermetically closed.

According to a particular embodiment of the invention, the volume of the closed space is increased by deflating the deformable envelope.

According to a particular embodiment of the invention, the controlled gaseous environment, once the controlled gas injection step has ended, has a pressure greater than atmospheric pressure outside the enclosure. This characteristic makes it possible to limit the risks of infiltration of unwanted gases into the closed space.

According to a particular embodiment of the invention, the enclosure comprising at least one inflatable envelope, the inflation gas of the envelope is identical to the controlled gas.

This simplifies the logistics of creating the controlled gaseous environment.

5. List of figures

Other characteristics and innovative advantages will emerge from the description below, provided for information and in no way limitative, with reference to the appended drawings, in which:

Figure la shows a schematic view of an enclosure in a gas purging step in the closed space according to a first embodiment of the invention;

Figure lb shows the enclosure of Figure la in a gas injection step constituting the controlled gas environment;

FIG. 2a represents a schematic view of an enclosure in a step of reducing the volume of the closed space according to a second embodiment of the invention;

Figure 2b shows the enclosure of Figure 2a in a gas injection step constituting the gaseous environment controlled;

Figure 3a shows a schematic view of an enclosure in a gas purging step in the closed space according to a third embodiment of the invention;

Figure 3b shows the enclosure of Figure 3a in a gas injection step constituting the controlled gas environment;

FIG. 4 represents a schematic perspective view of an enclosure according to the second embodiment of the invention;

FIG. 5 represents a schematic front view of an enclosure according to the third embodiment of the invention;

ίο FIG. 6 represents a functional diagram of an inflation circuit according to an embodiment of the invention;

FIG. 7 represents a functional diagram of a circuit comprising a gas supply circuit, a purge circuit and a recycling circuit according to an embodiment of the invention.

6. Detailed description

Figures la and lb show an enclosure 1 according to a first embodiment of the invention. The enclosure 1 contains a machine M intended to operate in a controlled gaseous environment. The machine M is for example a machine tool, a robot arm, a machining machine, a mono and / or multi-material additive printing machine comprising one or more printheads or a mechanical assembly machine or making mechanical welds. As a variant, the enclosure 1 contains a set of machines. The materials worked in the machine M are for example metals such as steel, stainless steel, aluminum, tungsten and all their derivatives or polymers, glass, ceramics or carbon. The controlled gaseous environment is composed of a controlled gas G, for example comprising an inert gas or a composition of gases including argon, helium, carbon dioxide, dioxygen, nitrogen or any other necessary gas the machine M.

Figures la and lb also respectively represent a first step and a second step of a first method according to the invention. The first method allows the creation of the gaseous environment controlled in the enclosure 1 by replacing the gas initially contained in the enclosure by the controlled gas G. For this purpose, the enclosure 1 comprises a closed space 4 with variable volume. The closed space is delimited by rigid walls 11 of the enclosure and by inflatable deformable envelopes 6. Each deformable envelope 6 forms a pocket in the enclosure 1, the increase in the volume of the pocket reducing the volume of the closed space 4 and vice versa. The enclosure also includes a purge circuit (shown in Figure 7) arranged to evacuate the gaseous environment contained in the closed space, a supply circuit (shown in Figure 7) arranged to inject the controlled gas into the space closed and an inflation circuit (shown in FIG. 6) arranged to inflate the deformable envelope 6.

The first step shown in Figure la corresponds to a step of purging the gas contained in the closed space 4 simultaneously with the reduction of the volume of the closed space. The volume of the closed space is reduced by inflating the deformable envelope 6 by means of the inflation circuit. Thus, the volume of the pocket formed by the deformable envelope 6 increases with inflation, thereby reducing the volume of the closed space. Reducing the volume of the closed space tends to increase the pressure of the gas initially contained in the closed space. Under the effect of this increase in pressure, the gas is expelled into the purge circuit provided for this purpose. In accordance with what will be described later, according to one embodiment of the invention, the purging circuit comprises suction means arranged to suck the gas initially contained in the closed space so as to promote the purging of the closed space . The deformable envelopes 6 are each fixed at an attachment point on a rigid wall 11 inside the enclosure 1 and arranged so as to occupy, once inflated, all the volume available in the enclosure, that is to say that is to say in order to reduce the closed space to a minimum volume by conforming to the contours of the machine and of the other elements contained in the enclosure and by being pressed against the walls of the enclosure. In the example, the minimum volume corresponds to the size of the machine. The closed space is thus practically empty of gas. Optionally, the envelopes 6 comprise motorized storage means making it possible to fold and unfold the envelopes in a protection.

The second step shown in FIG. 1b corresponds to a step of injecting controlled gas simultaneously with the increase in the volume of the closed space 4. The increase in the volume of the closed space 4 is carried out by deflating the deformable envelopes 6. Thus, when the second step is initiated, the closed volume is practically empty of gas. During the second stage, the closed volume gradually increases and fills with controlled gas injected by the supply circuit. At the end of the second step, the deformable envelopes 6 are completely deflated so as to have a reduced bulk, so that the volume of the closed space 4 is practically equal to the volume of the enclosure 1. Thus, at the after the first step and then the second step of the process, the enclosure 1 contains the controlled gaseous environment required for the proper functioning of the machine M.

Figures 2a and 2b show an enclosure 1 'according to a second embodiment of the invention. The enclosure 1 ′ contains a machine M intended to operate in a controlled gaseous environment comprising a controlled gas G in a manner similar to that which has been described for FIGS. 1a and 1b.

FIGS. 2a and 2b also respectively represent a first step and a second step of a second method according to the invention. The second method allows the creation of the controlled gaseous environment in the enclosure 1 ′ by injecting the controlled gas G simultaneously with the increase in the volume of the enclosure 1 ′. For this purpose, the enclosure 1 ′ has a closed space 4 ′ with variable volume. The closed space 4 'is delimited by the walls 11' of the enclosure, the walls comprising a portion consisting of a deformable envelope 6 '. The deformable envelope 6 ′ has a retracted position and a deployed position. Alternatively, the enclosure has intermediate positions between the retracted position and the deployed position. What is described below for the passage between the retracted position and the deployed position is also true for the passage between an intermediate position and the deployed position or for the passage between a retracted position and an intermediate position or even for the passage between an intermediate position and another intermediate position. The passage from the retracted position to the deployed position of the deformable envelope 6 'causes the volume of the closed space 4' to increase, and the passage from the deployed position to the retracted position of the deformable envelope 6 'causes the reduction of the volume of the closed space 4 '. The deformability of the envelope can be obtained in different ways, for example by using an envelope composed of several rigid articulated portions or by using a flexible envelope. The flexible envelope can be elastically deformable or not.

The enclosure also includes a purge circuit (shown in Figure 7) arranged to evacuate the gaseous environment contained in the closed space, a supply circuit (shown in Figure 7) arranged to inject the controlled gas into the space closed and if necessary an inflation circuit (shown in FIG. 6) arranged to inflate the frames of the enclosure.

The first step shown in Figure 2a corresponds to an initial step in which the deformable envelope 6 'is in a retracted position. The enclosure 1 ′ in this initial stage has a reduced closed space. The reduced closed space corresponds for example to the size of the machine so that the closed space is practically empty of gas. As a variant, the reduced closed space already contains, for example, a controlled gaseous environment obtained by means of the first process.

The second step shown in FIG. 2b corresponds to a step of injecting controlled gas simultaneously with the increase in the volume of the closed space 4 '. The volume of the closed space 4 ′ is increased by passing from the retracted position to the deployed position of the deformable envelope 6 ′. Thus, when the second step is initiated, the closed volume is practically empty of gas or else already contains a controlled gaseous environment. During the second stage, the closed volume gradually increases and fills with controlled gas injected by the supply circuit. At the end of the second step, the deformable envelope 6 'is in the deployed position. Thus, the volume in the enclosure containing the controlled gaseous environment required for the proper functioning of the machine M is increased.

Figures 3a and 3b show an enclosure 1 '' according to a third embodiment of the invention. The enclosure 1 '' contains a machine M intended to operate in a controlled gaseous environment comprising a controlled gas G in a manner similar to that which has been described for FIGS. 1a and 1b.

Figures 3a and 3b also respectively represent the first step and the second step of the first method according to the invention already described in Figures la and lb. Thus, the enclosure has a 4 '' closed space with variable volume. The closed space 4 '' is delimited by walls 11 '' of the enclosure which can be rigid or flexible and by deformable envelopes 6 '' inflatable. Each deformable envelope 6 '' forms a pocket in the enclosure 1 '', increasing the volume of the pocket reducing the volume of the closed space 4 '' and vice versa. The enclosure also includes a purge circuit (shown in Figure 7) arranged to evacuate the gaseous environment contained in the closed space, a supply circuit (shown in Figure 7) arranged to inject the controlled gas into the space closed and an inflation circuit (shown in FIG. 6) arranged to inflate the deformable envelope 6 '' and possibly the frames of the enclosure.

The enclosure 1 '' of Figures 3a and 3b differs from the enclosure 1 of Figures la and lb in that it further comprises a gasket 8 '' gas seal with the ground S. The seal 8 '' is made by an inflatable element. Alternatively, the seal 8 '' includes at least one portion of polytetrafluoroethylene lip seal.

In the example of Figures 3a and 3b, the enclosure 1 '' has the shape of a bell. The 1 '' enclosure can be operated, for example by means of a crane, a robotic arm or a drive system comprising a cable and a pulley. Thus, before carrying out the process for creating a controlled gaseous environment, the enclosure 1 '' is lifted away from the ground to allow the routing of a machine M to a point on the ground vertically the enclosure 1 '', then the enclosure is placed on the ground so as to include the machine M. The seal 8 '' seals the enclosure 1 '' once placed on the ground so as to obtain a space closed 4 '' hermetic. As a variant, the enclosure 1 '' is moved to be placed on the ground so as to encompass the machine M without the need to move the machine M.

The deformable envelopes can for example include the following materials: oxford cloth, parachute cloth coated with PVC, cloth coated with PVC, PVC, latex, elastomer rubber, polyester coated with PVC.

According to a particular embodiment of the method of the invention, the controlled gaseous environment, once the controlled gas injection step has ended, has a pressure greater than atmospheric pressure outside the enclosure.

According to a particular embodiment of the method of the invention, the enclosure comprising at least one inflatable envelope, the inflation gas of the envelope is identical to the controlled gas.

FIG. 4 represents an enclosure 41 according to the second embodiment of the invention. The enclosure 41 has a tunnel shape and has a bottom wall 410 resting on the ground, a front wall 411 and a rear wall 411 ′ substantially in the form of a half disc in a deployed position of the enclosure, the front corresponding to the front of the figure, and side walls 46 forming the arch of the tunnel. According to a particular embodiment, the side walls 46 are formed, at least in part, by a deformable envelope so as to allow the enclosure to pass from a retracted position to a deployed position and vice versa in accordance with what has been described in Figures 2a and 2b. In order to support the side walls 46, the enclosure 41 further comprises arches 40 in the form of an arch making it possible to stiffen the structure of the enclosure 41. In order to promote the compactness of the enclosure in a storage configuration, the reinforcements are for example inflatable tubes. Alternatively, the frames are made of metal, plastic or foam for example. The front wall 411 and the rear wall 411 ′ may be rigid or flexible, deformable or not. In the example, the front wall 411 and the rear wall 411 ′ are made of the same material as the side walls 46. In the example, the bottom wall is integral with the enclosure 41 and made of a material deformable at same as the side walls 46 in order to obtain a closed space in the enclosure which is airtight while retaining the retractable nature. As a variant, the enclosure 41 includes a gas seal with the ground, in a similar manner to what has been described in FIGS. 3a and 3b. The shape of the enclosure 41 can be obtained on the ground by various means: by straps, by stitching on the ground, by gluing, by sliding rails allowing the frames to be pushed back to a single point without being deflated or dismantled by reducing the depth of the construction volume while keeping its height and width.

FIG. 5 represents an enclosure 51 according to the third embodiment of the invention. The enclosure 51 has a bell shape the base of which is situated in a horizontal plane and has walls 56 assembled according to substantially vertical junction planes and passing through the top of the bell to form the dome of the enclosure in a position deployed. According to a particular embodiment, the side walls 56 are formed, at least in part, by a deformable envelope so as to allow the enclosure to pass from a retracted position to a deployed position and vice versa in accordance with what has been described in Figures 2a and 2b. In order to support the side walls 56, the enclosure 51 also comprises reinforcements 50 in the form of an arc of a circle and situated in the junction planes making it possible to stiffen the structure of the enclosure 51. In order to promote the compactness of the 'enclosure in a storage configuration, the frames are for example inflatable tubes. Alternatively, the frames are made of metal, plastic or foam for example.

The enclosure 51 includes a joint 58 gas tightness with soil S, of way similar at what has been described to the figures 3a and 3b. In variant, 1 ' enclosure 51 has a

lower wall forming the base of the bell and making it possible to obtain an airtight closed space. The enclosure also includes a ring 55 providing a grip on the means for moving the enclosure.

According to a particular embodiment, for example in the case of an enclosure with deformable walls such as the enclosure 41 or the enclosure 51, the closed space comprises a motorized structure arranged to vary the volume of the closed space.

In the case where the enclosure does not have a gas seal, the enclosure has an opening providing access to the closed space, preferably capable of being closed in a gas-tight manner. According to a particular embodiment, the enclosure further comprises an airlock at the interface between the access to the closed space and the outside of the closed space making it possible to guarantee stability of the controlled gaseous environment even when the opening is open. The airlock has an operation

identical speakers example. to that of a containment lock or allowing entry into of the through in clean rooms The figure 6 represents a functional scheme a

inflation circuit 7 according to the invention. The inflation circuit 7 includes:

a source of inflation gas 71,

- a positive and negative pressure pump 72,

an inflation valve 73,

- an inflation pressure sensor 74, and

- A nozzle 75 for diffusing the inflation gas in the envelope 6, the nozzle having one end opening into the envelope 6 and preferably located as far as possible from the attachment point of the envelope. Alternatively, the inflation gas source has sufficient pressure to inflate the envelopes and the envelope storage means are sufficient to expel the gaseous content therefrom. The positive and negative pressure pump 72 is then optional.

FIG. 7 represents a functional diagram of a circuit comprising a gas supply circuit 3, a purge circuit 2 and a recycling circuit 9 according to the invention.

The supply circuit 3 includes:

a controlled gas source 31, for example a pressurized gas bottle or a storage rack,

a supply pressure sensor 33, and

- two supply valves 32 and 34.

The purge circuit 2 includes:

- a purge valve 21,

- a purge pressure sensor 22,

- a negative pressure pump 23,

a gas analyzer 24, and

- a non-return valve 25.

The gas analyzer 24 is for example robotized and uses mechatronic functions. The analyzer comprises for example the following control means: pellets, electrochemical sensors, infrared sensors, pressure sensors and humidity sensor.

The recycling circuit 9 includes:

a filter 92 adapted to the controlled gas, and

a switch valve 91 having a discharge position directing the flow in the circuit from a first portion of the purge circuit 2 comprising the purge valve 21, the purge pressure sensor 22, the negative pressure pump 23, and the gas analyzer 24 to a second portion comprising the non-return valve 25; and a recycling position directing the flow in the circuit from the first portion of the purge circuit 2 to the filter 92 of the recycling circuit.

After the filter 92, the flow joins the supply circuit at a point located between a first portion of the supply circuit comprising the controlled gas source 31 and the supply valve 32 and a second portion of the supply circuit comprising the supply pressure sensor 33 and the supply valve 34, the second portion of the supply circuit opening into the enclosure 1.

The enclosure further comprises a fan arranged to stir the controlled gaseous environment.

In detail, the creation of the gaseous environment controlled in the enclosure 1 by replacing the gas initially contained in the enclosure by the controlled gas G according to the first method of the invention is carried out as follows.

Firstly, the machine M is placed in the enclosure 1 as well as all the material necessary for the operation of the machine M then the enclosure 1 is hermetically closed to obtain the closed space 4.

Then, the opening of the purge valve 21 allows the gas located in the closed space to exit. Optionally, the negative pressure pump 23 is started to allow the closed space to be placed under vacuum. Under the effect of the pressure thus generated in the purge circuit, the non-return valve 25 opens allowing the expulsion of the purged gas towards the outside of the enclosure 1. As a variant, the non-return valve is replaced by a second purge valve.

Then, the opening of the inflation valve 73 allows the passage of the inflation gas from the inflation gas source 71 towards the envelope 6. In the case where the enclosure comprises several envelopes 6 inflated with the gas coming from the same source of inflation gas 71, the inflation circuit is branched into as many branches as there are casings 6 to be inflated and each branch comprises at least one inflation valve 73, an inflation pressure sensor 74 and a nozzle 75 for diffusing the gas inside the corresponding casing 6. The presence of an inflation valve 73 in each branch allows the establishment of an inflation priority of the envelopes to gradually expel the gas to the purge circuit in order to allow optimal purging of the closed space. The inflation valves 73 can be successively opened and then closed after inflation. The inflation pressure sensors 74 make it possible to measure the pressure inside each envelope 6. In addition, the purge pressure sensor 22 makes it possible to control the pressure in the closed space during the purge.

Once inflation is complete, the purge valve 21 is closed. If a pressure measurement by the purge pressure sensor 22 is necessary outside the purge step, the purge pressure sensor 22 can be placed upstream of the purge valve 21 so as to be in communication with the closed space regardless of the closed or open state of the purge valve 21. As a variant, a second valve may be provided downstream of the purge pressure sensor in order to allow the hermetic closure of the closed space while leaving the purge valve 21 open.

Then, the controlled gas G is injected by the supply circuit 3 into the closed space 4 at a pressure slightly higher than that in the envelopes 6. Thus, the two supply valves 32 and 34 are open so as to leave the gas under pressure in the controlled gas source 31 propagates into the closed space 4. The supply pressure sensor 33 makes it possible to control the pressure in the supply circuit so as to ensure that the gas controlled G propagates well into the closed space 4. Simultaneously, the envelopes 6 are deflated by the inflation circuit 7 while maintaining the pressure in the closed space greater than the pressure outside the enclosure 1. Thus, the inflation valve 73 is open and the positive and negative pressure pump 72 is adjusted to create a vacuum (negative pressure) in the envelope 6 so that the gas in the envelope is sucked by the nozzle 75. In the case of a e envelope comprising motorized storage means, the storage means can fold or roll up the envelope so as to expel the gaseous content therefrom. The pressure level in the closed space is controlled by means of the purge pressure sensor 22 and the pressure level in each casing 6 is controlled by the corresponding inflation pressure sensor 74. This step ends when the envelopes 6 are completely deflated and when the targeted controlled gaseous environment is obtained. The envelopes 6 can then be stored in the storage means.

The gas analyzer 24 makes it possible to control the composition of the controlled gaseous environment. The gas analyzer 24 is placed either upstream of the purge valve 21 so as to allow control regardless of the state of the purge valve 21, closed or open; either downstream, when the control is carried out only with a bleed valve 21 open.

In order to improve the quality of the gaseous controlled environment obtained, the above actions can be repeated several times until the required level of quality is obtained.

Once the controlled gaseous environment has been obtained, the machine M can be put into operation.

In addition, the controlled gaseous environment can be stirred by the fan or by moving the material contained in the enclosure 1 so as to homogenize the composition of the gaseous environment controlled at any point of the enclosure.

In the event of degradation of the controlled gaseous environment during the operation of the machine M, an additional controlled gas injection is carried out. In the event of significant degradation of the gaseous environment controlled and if the operation of the machine M allows it, the first process according to the invention described above is carried out again.

To maintain the quality of the controlled gaseous environment, the controlled gaseous environment can be recycled through the recycling circuit. The switch valve is then placed in the recycling position. The negative pressure pump 23 is started up so as to create a flow from the closed space, through the first portion of the purge circuit then through the switch valve 91, then through the filter 92 and finally to through the second portion of the supply circuit to the closed space again. Thus, the controlled gaseous environment is filtered so as to remove unwanted particles or gases therefrom. The purge valve 21 and the supply valve 34 are then open.

According to a particular embodiment, the second portion of the supply circuit leads directly to the machine M. For example, in the case of additive printing machines the controlled gas is supplied by a gas nozzle of the machine for example in the processes by plasma arc or TIG, MIG, MAG type processes, arc strength, STT, CMT, CMT Advance, A-TIG, TOPTIG as well as the processes by direct supply of wire with fusion and more particularly the processes using a nozzle mounted on a multi-axis arm allowing the deposit of a molten material on a substrate where it solidifies. The second portion of the supply circuit can also lead directly to the machine M in the case of processes such as direct powder supply with fusion which use gases in their operations such as Laser Metal Deposition (LMD), Direct Metal Deposition (DMD), Direct Laser Déposition (DLD), Laser Engineered Net Shaping (LENS), Laser Cladding and Laser Déposition Welding and Powder Fusion Welding. The second portion of the supply circuit can also lead directly to the machine M in the case of processes requiring controlled gaseous environment such as additive powder bed manufacturing processes, including non-melting metal processes such as Metal Binder Jetting, and powder bed processes with fusion such as Laser Beam Melting (LBM) and Electron Beam Fusion (EBM).

Once the operation requiring a controlled gaseous environment is complete, the controlled gas is evacuated and the atmosphere outside the enclosure introduced into the closed space. For this purpose, the enclosure comprises for example a venting valve (not shown) and a discharge valve (not shown). To allow the introduction of the external atmosphere into the enclosure, the venting valve is open and to allow the evacuation of the controlled gas to the outside of the enclosure, the exhaust valve is also opened. As an option, the exhaust valve is equipped with an outside suction system to promote the expulsion of the controlled gas.

Alternatively, the controlled gas can be recovered for later re-use. To do this, the switch valve 91 is placed in the recycling position, the supply valve 32 is open, the supply valve 34 is closed, the purge valve 21 is open and the negative pressure pump 23 is start up. Thus, the controlled gas is sucked into the first portion of the purge circuit then through the switch valve 91, then through the filter 92 and finally through the first portion of the supply circuit to the gas source controlled 31. In order to promote the expulsion of the controlled gas in the purge circuit, the envelopes 6 can be inflated again.

To save the gas used, it is possible to use the same gas for inflating the envelopes and for creating the controlled gaseous environment. A controlled gas transfer network is set up between the controlled gas source 31 and the inflation gas source

71. The transfer network is equipped with a pressure / vacuum pump to promote the controlled gas transfer.

In detail, the creation of the gaseous environment controlled in the enclosure 1 ′ according to the second method of the invention is carried out as follows.

Firstly, the machine M is placed in the enclosure 1 ′ as well as all the material necessary for the operation of the machine M then the enclosure 1 ′ is hermetically closed to obtain the closed space 4 ′.

The residual gases in the closed space are purged and then the controlled gas is injected until the targeted gaseous environment is obtained, using the same steps as those described above for the first process. The injection of controlled gas is carried out simultaneously with the increase in the volume of the closed space 4 '. The volume of the closed space 4 ′ is increased by passing from the retracted position to the deployed position of the deformable envelope 6 ′.

In the case of an enclosure comprising inflatable armatures, the armatures are inflated simultaneously or following the injection of controlled gas into the closed space.

If a problem relating to the composition / quality of the controlled gaseous environment is encountered, the closed space is purged again by means of the purge circuit in accordance with what was described in the first method. Simultaneously with the purging of the closed space, the volume of the closed space 4 'is reduced by passing from the deployed position to the retracted position of the deformable envelope 6'. During this operation, the frames can be removed or deflated to help reduce the volume of the closed space. Then, the controlled gas is injected again until the targeted gaseous environment is obtained using the same steps as those described above.

In order to improve the quality of the gaseous controlled environment obtained, the above actions can be repeated several times until the required level of quality is obtained.

The characteristics and functionalities described within the framework of the first method can be integrated into the second method.

Optionally, the enclosure 1 ′ may include within it a rigid enclosure 1 for storing equipment according to the first embodiment of the invention.

Also optional, the enclosure further comprises a gas cooling system integrated into the supply circuit and / or the recycling circuit and / or into a wall of the enclosure. The cooling system is for example a network of conduits in which a cooling liquid such as water circulates.

The invention is described in the foregoing by way of example. It is understood that the person skilled in the art is able to carry out different variant embodiments of the invention, for example by combining the different characteristics above taken alone or in combination, without however departing from the scope of the invention .

Claims (13)

1. Enclosure (1, 1 ', 1' ') intended to contain a machine (M) or a work area requiring a controlled gaseous environment composed of at least one controlled gas (G), said enclosure comprising a circuit supply (3) of controlled gas (G), characterized in that it includes a closed space (4, 4 ', 4' ') with variable volume into which the supply circuit injects the controlled gas. 2. Enclosure (1, 1 ', 1' ') according to claim 1, characterized in that it comprises a purge circuit (2) arranged to evacuate the gaseous environment contained in the closed space (4, 4' , 4 ''). 3. Enclosure (1, 1 ', 1' ') according to claim 1 or 2, characterized in that the closed space (4, 4', 4 '') is delimited at least in part by a deformable envelope (6 , 6 ', 6' '). 4. Enclosure (1, 1 ', 1' ') according to claim 3, characterized in that the deformable envelope (6, 6', 6 '') is inflatable. 5. 1 ' 4 6. characterized 6 '') forms in that the deformable envelope minus a pocket in the enclosure, increasing the volume of the space Enclosure claims 3 volume closed according to 5, of the pocket reducing the (4, 4 '') and vice versa. 1 'any one of characterized in that the deformable envelope (6') comprises at least one portion also delimiting the enclosure (1 '). 7. Enclosure (1 '') according to any one of the preceding claims, characterized in that it comprises a gas-tight seal (8 '') with the ground (S). 8. Machine (M) intended to operate in a controlled gaseous environment composed of at least one controlled gas (G), said machine (M) comprising a supply circuit (3) in controlled gas (3) and characterized in that that it further comprises an enclosure comprising a closed space (4, 4 ', 4' ') of variable volume into which the supply circuit injects the controlled gas. 9. Machine (M) according to claim 8 characterized in that it is an additive printing machine or a machining machine. 10. Method for creating a controlled gaseous environment composed of at least one controlled gas (G) in an enclosure (1, 1 ', 1' ') intended to contain a machine or a work area requiring the gaseous environment controlled, the enclosure (1, 1 ', 1 '') comprising a closed space (4, 4 ', 4' ') with variable volume and a supply circuit (3) of controlled gas, the method being characterized in that it comprises a step of injecting gas controlled simultaneously with the increase in the volume of the closed space. 11. Method according to the characterized in that, further comprising a method comprises, before controlled, a step of preceding claim the enclosure (1, 1 ', 1' ') purge circuit (2), the step d gas injection purges the gas contained in the closed space simultaneously with the reduction in the volume of the closed space. 12. Method according to claim 10 characterized in that the increase in the volume of the closed space is achieved by increasing the volume of the enclosure. 13. Method according to claim 11 characterized in that, the enclosure comprising at least one inflatable deformable envelope (6, 6 '') forming a pocket inside the enclosure, the reduction in the volume of the closed space is made by inflating the deformable envelope.