A device for repotting pots from a tank containing metallic powder recovered after a powder bed additive manufacturing process

Abstract

A device for refilling pots from a tank containing metal powder recovered after a powder bed additive manufacturing process. The invention relates to a device (10) for refilling pots (20) from a tank (12) containing metal powder recovered after a powder bed additive manufacturing process. The device (10) comprises a conduit (14) having a powder inlet (16) for connection to the tank (12) and a powder outlet (18) for feeding a pot (20) located opposite said outlet (18), means (22) for controlling the filling of the pots (20) comprising at least one controlled valve (24) for controlling the passage of powder in the conduit (14) and means (40) for measuring the quantity of powder poured into the pot (20), and a platform (42) for supporting the pots (20), said platform (42) being rotatable about an axis. (X),so that the pots (20) can be arranged successively opposite the powder outlet (18). Figure to be published with the abbreviation: Figure 1,

Description

Title of the invention: Device for repotting pots from a tank containing a metal powder recovered at the end of an additive manufacturing process on a powder bed TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a device for repotting pots from a tank containing a metal powder, and a method for repotting pots with a metal powder recovered at the end of an additive manufacturing process on a powder bed using a device according to the invention.

[0002] CONTEXT

[0003] Powder bed fusion, also known as Laser Beam Melting (LBM), is an additive manufacturing process using metal powder to manufacture parts on a plate by adding successive layers of material (metal powder). Manufacturing a part on a plate can require several hundred kilos of powder. This powder can be recycled and reused via a suction means and is packaged in reusable tanks, particularly stainless steel, and adapted to the manufacturing method.

[0004] After a certain number of recyclings, the powder can no longer be reused for industrial purposes. It is therefore collected in tanks and emptied into potting pots, typically made of plastic, before being destroyed.

[0005] It is known to recover the powder from the tank and transfer it to the pots manually. This is the action of repotting, that is to say, filling the pots. However, manual repotting by an operator creates risks to his health due to the multiplication of repetitive gestures, and prolonged exposure to the metal powder. Indeed, most metal powders for additive manufacturing present high risks in terms of safety, security and environment, and are carcinogenic, toxic or even explosive for some.

[0006] Metal powders for additive manufacturing in the present context have a particle size between 10 and 100 pm and can be inhaled into the deepest areas of the lungs. It is therefore necessary to avoid suspensions of said powders in the air.

[0007] It is also known to place an adapter between the tank and the pot to be filled in order to empty the tank directly into the pot. However, despite the adapter, the operator has no visibility of the filling state of the pot and is forced to check by removing and replacing the pot several times. In addition, such an action is time-consuming and requires an operator to stay nearby for several hours to supervise the repotting in order to empty all the powder tanks into the pots. PRESENTATION OF THE INVENTION

[0008] The invention aims to remedy the aforementioned drawbacks, by proposing a device for repotting pots from a tank containing a metal powder recovered at the end of an additive manufacturing process on a powder bed limiting manual operations, thus reducing the risks of exposure to the powder and saving time for an operator.

[0009] To this end, the present invention relates to a device for repotting pots, from a tank containing a metal powder recovered at the end of an additive manufacturing process on a powder bed, the device comprising, - a conduit comprising a powder inlet intended to be connected to the tank and a powder outlet intended to supply a pot located opposite said outlet, - means for controlling the filling of the pots comprising at least one controlled valve for controlling the passage of powder in the conduit and means for measuring the quantity of powder poured into the pot, - a tray intended to support the pots, said tray being movable in rotation around an axis, so as to be able to successively arrange the pots opposite the powder outlet.

[0010] Such a device makes it possible to secure the repotting process with respect to the operators while saving time by limiting manual operations and automating the process. Indeed, thanks to the means for controlling the filling of the pots, the means for measuring the quantity of powder poured into the pot and the movable tray, it is no longer necessary to mobilize an operator to monitor the filling of the pots and to change pots when the repotting of a pot is finished.

[0011] The powder outlet may be movable in translation between a deployed position in which it is able to come to bear on a filling opening of a pot, and a retracted position in which said powder outlet is spaced from said opening.

[0012] The conduit may be telescopic and comprise at least one fixed part comprising the powder inlet and a part movable in translation relative to the fixed part, said movable part comprising the powder outlet. Said movable part may be guided, for example by means of guide rods. The device may for example comprise two guide rods arranged on either side of the axis of translational movement of the outlet.

[0013] Said powder outlet can be moved in translation by means of an actuator.

[0014] Said actuator may be a cylinder, for example a hydraulic cylinder, a cylinder electric or pneumatic cylinder. The cylinder can be a single-acting cylinder or a double-acting cylinder.

[0015] It should be remembered that a single-acting cylinder is only active in one direction, the other direction of movement being ensured passively.

[0016] Conversely, a double-acting cylinder can be active in two opposite directions.

[0017] Alternatively, the actuator may be a motor associated with transformation means. from a rotational movement at the output of a motor shaft to a translational movement, such as for example a cam.

[0018] Said conduit may be equipped with return means capable of returning the outlet of the conduit to its deployed position.

[0019] Such return means are particularly useful when the actuator used for moving the powder outlet is a single-acting actuator.

[0020] The return means may be elastic return means. The elastic return means may comprise at least one helical spring. Said spring may be a compression spring or a tension spring. Said spring may be mounted around a aforementioned guide rod.

[0021] The valve can be controlled from a setpoint signal, itself a function of a signal from the means for measuring the quantity of powder poured into the pot.

[0022] The means for measuring the quantity of powder may comprise at least one scale.

[0023] Said scale may be capable of determining the mass of all the pots supported by the tray.

[0024] Said scale can thus be arranged between the tray and a fixed part of the device.

[0025] Alternatively, said means for measuring the quantity of powder may comprise optical means or any other appropriate means.

[0026] Said powder outlet may comprise a section reduction zone.

[0027] Such a section reduction zone makes it possible to improve the guidance of powder in the filling opening of the pot, and thus to adapt to a wide range of pots. Such an opening can have a diameter of between 50 mm and 150 mm.

[0028] The device may comprise a box containing at least a portion of said conduit, the means for controlling the filling of the pots and the tray. The fixed portion of the conduit may extend beyond the box, the tank being external to said box. The box may comprise a door allowing the insertion of the pots and their placement on the tray.

[0029] The present invention also relates to a method for repotting pots with a metal powder recovered at the end of an additive manufacturing process on a powder bed using a device as defined above, said method comprising the steps consisting of: - connect a tank containing a metal powder to the inlet of the conduit, - place at least one pot on the device tray, - adjust the angular position of the plate relative to the conduit outlet, by rotating the plate, - fill the pot by opening the controlled valve then closing the controlled valve when sufficient filling of the pot is detected using the means for measuring the quantity of powder.

[0030] After filling a pot and in the case where several pots to be filled are arranged on the tray, the tray can be pivoted so as to place a new pot to be filled opposite the outlet of the conduit.

[0031] When the filling of a pot is finished, an automatic closing of the pot can be carried out.

[0032] According to one embodiment of the method, the powder outlet is movable in translation between a deployed position in which it is able to come to bear on a filling opening of a pot, and a retracted position in which said powder outlet is spaced from said opening, said method comprising:

[0033] - prior to the step of filling the pot, moving the outlet of powder in deployed position,

[0034] - after the step of filling the pot, the displacement of the outlet of powder in retracted position.

[0035] The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example with reference to the appended drawings. BRIEF DESCRIPTION OF THE FIGURES

[0036] [Fig.l] [Fig.l] is a schematic perspective view of a potting device according to the invention and of potting pots, in which the outlet of the conduit is in the retracted position;

[0037] [Fig.2] [Fig.2] is a front view of the potting device of [Fig.l], in which the conduit outlet is in the deployed position;

[0038] [Fig.3] [Fig.3] is a perspective view from above of the conduit outlet of the potting device of [Fig.l] and a potting pot;

[0039] [Fig.4] [Fig.4] is a front view of the conduit outlet of the device repotting [Fig.l] and a potting pot. DETAILED DESCRIPTION OF THE INVENTION

[0040] A device 10 for repotting pots from a tank 12 containing a metal powder recovered at the end of a powder bed additive manufacturing process according to one embodiment of the invention is shown in [Fig.l].

[0041] The tank 12 may be a powder vacuum tank. Alternatively, the tank 12 may be a powder storage tank.

[0042] The potting device 10 comprises a conduit 14 having a powder inlet 16 intended to be connected to the tank 12 and a powder outlet 18 intended to supply a pot 20 located opposite said outlet 18.

[0043] The inlet 16 advantageously has any shape capable of placing an outlet of the tank 12 in fluid communication with the conduit 14. The inlet 16 may, for example, comprise a thread so as to screw the inlet 16 of the conduit 14 onto the outlet of the tank 12.

[0044] The conduit 14 has, for example, a cylindrical shape.

[0045] When the device 10 is in the position of use, the inlet 16 of the conduit 14 is placed above the outlet 18 of the conduit 14 so that the powder flows by gravity.

[0046] The conduit 14 is advantageously free of elbows for the same reason.

[0047] The conduit 14 may be transparent to allow the flow of the powder during a repotting operation.

[0048] The conduit 14 has, for example, a length taken between the inlet 16 and the outlet 18 of between 400 mm and 600 mm.

[0049] The conduit 14 has, for example, a diameter of between 80 mm and 150 mm.

[0050] The conduit 14 is, for example, made of metal or plastic.

[0051] Means 22 for controlling the filling of the pots 20 comprise at least one controlled valve 24 making it possible to control the passage of powder in the conduit 14.

[0052] The controlled valve 24 delimits a part 26 of the conduit comprising the inlet 16 of the conduit 14 and a part 28 of the conduit 14 comprising the outlet 18 of the conduit 14.

[0053] The controlled valve 24 allows a flow of powder from the inlet 16 of the conduit 14 to the outlet 18 of the conduit 14 when it is in the open position, and it prevents a flow of powder from the inlet 16 of the conduit 14 to the outlet 18 of the conduit 14 when it is in the closed position.

[0054] The part 28 of the conduit 14 comprising the outlet 18 of the conduit 14 advantageously has a diameter smaller than the diameter of the part 26 of the conduit 14 comprising the inlet 16 of the conduit 14. This makes it possible to store a larger volume of powder from the inlet 16 to the controlled valve 24 and to generate a more restricted and better directed flow from the controlled valve 24 to the outlet 28 to facilitate the filling of a pot 20. The conduit 14 can thus be telescopic.

[0055] The part 26 of the conduit 14 comprising the inlet 16 of the conduit 14 is fixed.

[0056] The part 28 of the conduit 14 comprising the outlet 18 of the conduit 14 is preferably movable in translation along an axis A between a deployed position (visible in [Fig.2]) in which the outlet 18 is able to come to bear on an opening 30 of filling a pot 20, and a retracted position (visible in [Fig.l]) in which said outlet 18 is spaced from said opening 30. This makes it possible to connect the outlet 18 in a sealed manner to a pot 20 in the deployed position, and to retract the conduit 14 between the filling of two successive pots 20.

[0057] Said powder outlet 18 can be moved in translation by means of an actuator.

[0058] According to the example of [Fig.l], the actuator is a single-acting electric cylinder and said movable part 28 is guided by means of two guide rods 32 arranged on either side of the axis A of translational movement of the output 18.

[0059] According to this example, said conduit 14 is equipped with return means 34 capable of returning the outlet 18 of the conduit to its deployed position. The return means 34 are in the form of two helical compression springs each mounted around a guide rod 32. This makes it possible to ensure sealing between the outlet 18 in the deployed position and an opening 30 for filling a pot 20.

[0060] The powder outlet 18 is for example made of a resilient material. This also makes it possible to improve the seal between the outlet 18 and the opening 30 for filling a pot 20 while resisting deformation.

[0061] Said powder outlet 18 preferably comprises a section reduction zone 35 visible in FIGS. 3 and 4. For example, the section reduction zone 35 of the outlet 18 is located at the periphery of the center 36 of the outlet 18, the section reducing from the periphery towards the center 36. Such a section reduction zone 35 makes it possible to improve the guidance of powder in the filling opening 30 of the pot 20, and thus to adapt to a wide range of pots.

[0062] The powder outlet 18 has at least one through orifice 38 allowing the powder to flow through said orifice 38. The orifice 38 may be circular in shape or any other shape suitable for the powder to flow.

[0063] The orifice 38 is preferably placed in the center of the outlet 18, in particular in the center of the section reduction zone 35.

[0064] According to the example shown, the orifice 38 has a diameter less than or equal to 50 mm.

[0065] The pot repotting device 10 further comprises means 40 for measuring the quantity of powder poured into the pot 20, and a plate 42 intended to support the pots 20, said plate 42 being movable in rotation around an axis X, so as to be able to successively arrange the pots 20 opposite the powder outlet 18.

[0066] According to the example shown, the measuring means 40 comprise a scale 44.

[0067] Said scale 44 may be capable of determining the mass of all the pots 20 supported by the plate 42. The scale 44 is in particular capable of transmitting to the controlled valve 24 a signal containing the mass of powder poured into a pot 20 being filled.

[0068] The valve 24 can be controlled from a setpoint signal, itself a function of said signal from the scale 44. In particular, the valve 24 is configured to be open until the setpoint signal is reached, and to close when the setpoint signal is reached. This makes it possible to pour the correct quantity of powder into a pot 20 without the need for control by an operator.

[0069] The tray 42 can also be controlled from the setpoint signal. When the setpoint signal is reached, the tray 42 can be pivoted so as to place a new pot 20 to be filled opposite the outlet 18 of the conduit 14.

[0070] Said scale 44 can thus be arranged between the plate 42 and a fixed part of the device 10. In particular, the plate 42 is supported by the scale 44.

[0071] Said plate 42 has for example a diameter between 400 mm and 450 mm.

[0072] The device 10 shown comprises a box 50 containing at least a portion of said conduit 14, the means 22 for controlling the filling of the pots 20 and the tray 42. This makes it possible in particular to ensure confinement of the device 10 to limit the exposure of an operator to the metal powder. The fixed portion 26 of the conduit 14 extends beyond the box 50. The box 50 is therefore provided with a through orifice 51. The box 50 may comprise a door or an opening allowing the insertion of the pots 20 and their placement on the tray 42.

[0073] The box 50 is for example equipped with casters. This allows easy movement of the device 10.

[0074] Advantageously, a support column 52 fixed to the box 50 allows the fixed part 26 of the conduit 14 to be held. The support column 52 is for example welded to the box 50.

[0075] The potting device 10 may further comprise a labeling machine (not shown). Such a labeling machine makes it possible to label the filled pots and thus ensure traceability of the potting pots.

[0076] A method of repotting pots 20 with a metal powder recovered at the end of an additive manufacturing process on a powder bed using a device 10 according to the invention will now be described.

[0077] Firstly, a tank 12 containing a metal powder is connected to the inlet 16 of the conduit 14. At least one pot is placed on the plate 42 of the device 10.

[0078] The angular position of the plate 42 is adjusted relative to the outlet 18 of the conduit 14, by rotation of the plate 42. Thus, the opening 30 for filling a pot 20 is placed opposite the powder outlet 18.

[0079] Advantageously, the powder outlet 18 is moved in translation into the deployed position. In particular, the actuator and the return means 34 allow the movement of the two guide rods 32 and thus of the powder outlet 18 until that the powder outlet 18 comes into contact with the filling opening 30 of the pot 20.

[0080] The pot 20 is then filled by opening the controlled valve 24.

[0081] When the means 40 for measuring the quantity of powder, in particular the scale 44, have detected sufficient filling of the pot 20, the controlled valve 24 is closed.

[0082] In particular, said scale 44 determines the mass of all the pots 20 supported by the tray 42. The scale 44 transmits to the controlled valve 24 a signal containing the mass of powder poured into a pot 20 being filled. The valve 24 is open until the set signal is reached, and closes when the set signal is reached.

[0083] Advantageously, after the step of filling the pot 20, the powder outlet 18 is moved in translation into the retracted position. In particular, the actuator and the return means 34 make it possible to retract the two guide rods 32 and thus the powder outlet 18.

[0084] After filling a pot and in the case where several pots 20 to be filled are arranged on the tray, the tray 42 can be pivoted so as to place a new pot 20 to be filled opposite the outlet 18 of the conduit 14.

[0085] When the filling of a pot 20 is finished, an automatic closing of the pot can be carried out.

[0086] Thanks to the method according to the invention, the filling of the pots is automated, thus improving the safety of the operators by limiting handling and exposure to the powder, but also saving time since it is possible to assign an operator to another task during the filling of the pots. The speed of execution of the method can be standardized and increase compared to the same execution by an operator.

Claims

Claims

1. Device (10) for repotting pots (20) from a tank (12) containing a metal powder recovered at the end of a powder bed additive manufacturing process, the device (10) comprising a conduit (14) having a powder inlet (16) intended to be connected to the tank (12) and a powder outlet (18) intended to supply a pot (20) located opposite said outlet (18), means (22) for controlling the filling of the pots (20) comprising at least one controlled valve (24) making it possible to control the passage of powder in the conduit (14) and means (40) for measuring the quantity of powder poured into the pot (20), a tray (42) intended to support the pots (20), said tray (42) being movable in rotation about an axis (X), so as to be able to successively arrange the pots (20) opposite the powder outlet (18).

2. Device (10) according to the preceding claim, in which the powder outlet (18) is movable in translation between a deployed position in which it is able to come to bear on an opening (30) for filling a pot (20), and a retracted position in which said powder outlet (18) is spaced from said opening (30).

3. Device (10) according to the preceding claim, wherein said powder outlet (18) is moved in translation by means of an actuator.

4. Device (10) according to claim 2 or 3, wherein said conduit (14) is equipped with return means (34) capable of returning the outlet (18) of the conduit (14) to its deployed position.

5. Device (10) according to one of the preceding claims, in which the valve (24) is controlled from a setpoint signal, itself a function of a signal from the means (40) for measuring the quantity of powder poured into the pot (20).

6. Device (10) according to one of the preceding claims, in which the means (40) for measuring the quantity of powder comprise at least one scale (44).

7. Device (10) according to one of the preceding claims, in which said outlet (18) comprises a section reduction zone (35).

8. Method for repotting pots (20) with a metal powder recovered at the end of an additive manufacturing process on a powder bed using a device (10) according to one of the preceding claims, said method comprising the steps of: - connecting a tank (12) containing a metal powder to the inlet (16) of the conduit (14), - placing at least one pot (20) on the plate (42) of the device (10), - adjusting the angular position of the plate (42) relative to the outlet (18) of the conduit (14), by rotating the plate (42), - filling the pot by opening the controlled valve (24) then closing the controlled valve (24) when sufficient filling of the pot (20) is detected using the means for measuring the quantity of powder.

9. Method according to claim 8, in which the powder outlet (18) is movable in translation between a deployed position in which it is able to come to bear on an opening (30) for filling a pot (20), and a retracted position in which said powder outlet (18) is spaced from said opening (30), said method comprising: - prior to the step of filling the pot (20), moving the powder outlet (18) into the deployed position, - after the step of filling the pot (20), moving the powder outlet (18) into the retracted position.

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