Device and method for the additive manufacture of a three-dimensional object

Abstract

The invention relates to a device for the additive manufacturing of all or part of a three-dimensional object (106) on a manufacturing support (104), said device comprising at least one array (20, 30) for the additive deposition of material, which array is intended to be arranged above the manufacturing support (104), extends along a longitudinal axis (X) and comprises a plurality of material deposition nozzles, each of which is provided with at least one dispensing opening, each of the material deposition nozzles comprising a closing means that is movable between a closing position and a plurality of opening positions of the dispensing opening, and an actuator for controlling the movement of the closing means between the closing and opening positions, the closing means being controllable independently of one another. The device comprises at least one actuation system configured to bring about a relative translational movement of the material deposition array relative to the manufacturing support (104) in at least one vertical direction (Z) and / or a longitudinal direction (X).

Description

[0001] DESCRIPTION

[0002] TITLE: Device and method for additive manufacturing of a three-dimensional object

[0003] The present invention relates to the field of manufacturing a three-dimensional object.

[0004] It is known to produce three-dimensional plastic objects from plastic injection molds.

[0005] Although such a manufacturing process allows the production of a large number of three-dimensional objects, the prior production of an injection mold increases the manufacturing time of the three-dimensional object.

[0006] We also know the material deposition processes in which the three-dimensional object is produced by projection of individual drops which are then photo-crosslinked. However, the generation of individual drops does not allow to obtain a three-dimensional object of satisfactory quality because the mechanical strength of the parts is not sufficient. Furthermore, the printing time is very long.

[0007] In the case of depositing “polyjet” type material, the problem is mainly linked to the choice of materials limited by the requirement to be crosslinkable by ultraviolet rays.

[0008] We also know about additive manufacturing by extrusion of a molten material, called "fused deposition modeling", with the acronym FDM in Anglo-Saxon terms.

[0009] It is known to use an extruder to produce a rod or thread of molten material from filaments or granules of thermoplastic or composite material.

[0010] However, current processes are particularly slow since the support is positioned at a given azimuth before the nozzle deposits material and the operation is repeated until the three-dimensional object is fully manufactured. Such a solution only allows the deposit of a few tens of grams per hour, for example 50g / h.

[0011] Furthermore, the slow manufacturing of the tread can cause seepage problems.

[0012] In this regard, reference may be made to document FR-B 1 -3 067 281, which proposes a system for manufacturing a tread for a tire of a tubeless integral wheel. The device comprises a construction robot comprising one or more nozzles for depositing material by addition. The nozzles are arranged side by side and movable laterally in order to be able to cover the entire tread to be constructed.

[0013] In order to reduce the manufacturing time of the three-dimensional object, large extruders with material depositing nozzles of 5 mm to 10 mm could be used. However, in this case, although the flow rate of deposited material is higher, around 900 g / h, the precision is much lower.

[0014] All the proposed solutions are therefore not satisfactory since they require a choice between the speed of manufacturing the three-dimensional object or the quality of the detail or geometry of said three-dimensional object.

[0015] To achieve a high throughput of deposited material while maintaining good quality of the geometry of the three-dimensional object, a large number of extruders could be used, for example between 100 and 200 extruders, each with its own trajectory. However, providing a hundred robot arms, each comprising an extruder and arranged around a three-dimensional object, is not feasible in terms of size and manufacturing cost.

[0016] Thus, there is a need to improve the devices for manufacturing a three-dimensional object.

[0017] The objective of the invention is to quickly manufacture a three-dimensional object while maintaining the quality of the detail of the three-dimensional object. The aim is thus to reduce the manufacturing time of a three-dimensional object and thus to deposit a significant quantity in a short time, of the order of 10 kg / h.

[0018] The present invention relates to a device for additive manufacturing of all or part of a three-dimensional object on a manufacturing support.

[0019] By "additive manufacturing" we mean a manufacturing process by adding extruded material, called "fused deposition modeling", with the acronym FDM in Anglo-Saxon terms.

[0020] The additive manufacturing device comprises at least one ramp for depositing material by addition intended to be arranged above the manufacturing support, and comprising a plurality of material deposit nozzles.

[0021] The material dispensing nozzles are each provided with at least one dispensing orifice.

[0022] Each of the material depositing nozzles comprises a closure means movable between a closure position and a plurality of opening positions of said dispensing orifice, and an actuator for controlling the movement of the closure means between the closure and opening positions, the closure means being controllable independently of one another.

[0023] Thus, each of the material deposition nozzles is configured to deposit molten material onto the manufacturing support, in particular onto a receiving surface according to several material deposition sequences.

[0024] By "open position" of said dispensing orifice is meant a fully open position of the dispensing orifice, but also the intermediate positions in which the dispensing orifice is partially open.

[0025] The opening of the dispensing orifice can advantageously be dependent on the material deposit flow rate. Indeed, controlling the opening of the dispensing orifice makes it possible to manage the material deposit flow rate by varying the position of the closure means, in particular the needle. The material deposit nozzles can be identical to each other or different, in terms of their dimensions, such as the diameter of the dispensing orifice, their height or their external dimension.

[0026] The additive manufacturing device further comprises at least one actuation system configured to generate a relative translational movement between the material deposit ramp and the manufacturing support in at least one vertical direction and / or one longitudinal direction.

[0027] Thus, when the material depositing ramp is moved, all of the material depositing nozzles are moved simultaneously, by means of the movement of the material depositing ramp.

[0028] The dispensing orifices of each of the nozzles can be closed independently of each other and reactively, so as to manufacture any detail on the supporting circumferential surface of the manufacturing support and in a short time.

[0029] The three-dimensional object is manufactured by depositing the extruded material layer by layer. The extruded material melts onto the previously deposited layer of material and solidifies when the temperature drops.

[0030] The longitudinal direction is parallel to the longitudinal axis of the ramp or coincident with the longitudinal axis of the ramp.

[0031] Advantageously, the additive manufacturing device comprises at least one extruder connected to the material depositing ramp and supplying said ramp with a rod of molten material.

[0032] For example, the extruder is associated with the set of material dispensing nozzles.

[0033] For example, the extruder is central. Alternatively, one could provide a layout other than central for the extruder.

[0034] A single central extruder reduces the footprint around the manufacturing support, as well as the manufacturing cost.

[0035] Alternatively, at least one extruder could be provided associated with at least one material dispensing nozzle. For example, several extruders could be provided, each associated with at least two material dispensing nozzles.

[0036] For example, molten rod can be obtained from pellets.

[0037] The material granules are for example made of plastic, for example thermoplastic, acronym TP or thermoplastic elastomer, acronym TPE. The material granules are therefore hot extruded.

[0038] Alternatively, the molten rod may be obtained from one or more filaments, or even strips. The molten rod may be either fragmented or continuous.

[0039] Preferably, the molten rod is continuous and not in the form of successive droplets in order to avoid any defect in the geometry of the object.

[0040] Advantageously, each material depositing nozzle comprises a chamber for receiving the molten material coming from the extruder in communication with the distribution orifice.

[0041] The dispensing orifice has, for example, a dimension between 0.6 mm and 1.5 mm, preferably between 0.6 mm and 0.8 mm to produce a deposit of material 1 mm wide and preferably between 1 mm and 1.5 mm to produce a deposit of material 2 mm wide.

[0042] For example, the dispensing orifice of each of the material depositing nozzles has a rectangular or circular section. A rectangular section makes it possible to improve the level of detail of the geometry of the three-dimensional object and the quality of interruptions by the sealing means.

[0043] For example, the additive manufacturing device comprises a fixed base and one or more material depositing ramps mounted in translation relative to said fixed base.

[0044] For example, the additive manufacturing device comprises at least two material depositing ramps, each associated with a specific actuation system and arranged at two given transverse positions above the manufacturing support. The shutter frequency of the temporary shutter means is, for example, between 10Hz and 30Hz, for example equal to 20Hz.

[0045] According to one embodiment, each of the temporary sealing means comprises a needle.

[0046] Alternatively, other shutters could be provided, such as, for example, slide shutters or another type of shutter configured to close or open the dispensing orifice.

[0047] The actuator comprises, for example, a piezoelectric device for closing or opening the dispensing orifice of the corresponding nozzle.

[0048] It could also be envisaged to use a pneumatic, magnetic, electric or hydraulic cylinder to close or open the distribution orifice of the corresponding nozzle.

[0049] The needle shutter allows for clean stops of the flow of molten material, without burrs, and clean restarts of said flow. Alternatively, any other shut-off system associated with each of the nozzles could be provided, such as a valve, for example.

[0050] The additive manufacturing device may comprise a volumetric metering device disposed downstream of the extruder and upstream of the material depositing ramp. For example, the volumetric metering device is a gear pump. The volumetric metering device is configured to deliver a calibrated quantity of molten material onto the supporting surface of the manufacturing support. Thus, material lines of constant width can be obtained.

[0051] Thanks to the volumetric dosing device, it is possible to control, in a repeatable manner throughout the manufacture of the object, the quantity of extruded material deposited. Controlling the quantity of extruded material also makes it possible to limit the loss of material not necessary for the manufacture of the object.

[0052] According to one embodiment, at least one of the material deposition nozzles is configured to deposit material over all thicknesses of at least one transverse line of material. By deposition of material along a "line of material" is meant the deposition of material on the supporting surface of the manufacturing support along an axis perpendicular to the longitudinal axis, for example the transverse axis in the case where the object to be manufactured is parallelepipedal or a circular trajectory in the case where the object to be manufactured is cylindrical.

[0053] By "thickness" we mean a layer of material deposited on a line of material, transverse or circular.

[0054] According to one embodiment, the material depositing nozzles are arranged on the material depositing ramp in a single row in the longitudinal direction.

[0055] In this case, all of the material depositing nozzles are configured to deposit a layer of material during a material depositing sequence, possibly during a movement of the receiving support in a direction of advancement, and said material depositing ramp is configured to have a relative translational movement along the vertical axis after each deposit of a layer of material.

[0056] By "direction of advancement" is meant the transverse direction in the case where the object to be manufactured is a parallelepiped or of a shape other than cylindrical or a rotation around the longitudinal axis in the case where the object to be manufactured is cylindrical.

[0057] Generally, the direction of advancement of the manufacturing support is perpendicular to the extension axis, for example longitudinal, of the ramp.

[0058] Thus, each of the material deposition nozzles is configured to deposit molten material along a corresponding material line, corresponding to a material deposition sequence, and after each material deposition sequence, i.e. after the manufacture of each layer of material, said material deposition ramp is configured to have a relative translational movement along the vertical axis relative to the manufacturing support and so on until the desired three-dimensional object is obtained.

[0059] By "material layer" is meant the set of lines of material side by side across the entire width of the three-dimensional object to be manufactured. A material layer corresponds to a thickness of molten material deposit. On a material layer, it could be provided that material is not deposited on one or more lines in order to achieve a particular geometric shape of the object to be manufactured.

[0060] In the case where the object to be manufactured is cylindrical, a layer corresponds to the set of circumferential lines.

[0061] Alternatively, in the case where the object to be manufactured is parallelepipedal or generally non-cylindrical in shape, a layer corresponds to the set of transverse lines.

[0062] By "row" is meant an arrangement along the longitudinal axis. A row is arranged along the width of the object to be manufactured.

[0063] The width of the object to be manufactured is defined as the dimension along the longitudinal axis. The width could also be the dimension along the transverse axis. Generally speaking, the width of the object to be manufactured corresponds to the extension dimension of the ramp.

[0064] The material deposit ramp may be configured to be moved in translation relative to the manufacturing support along the vertical axis. Alternatively, the material deposit ramp may be fixed relative to the base of the manufacturing device and it is the manufacturing support which is configured to be moved in translation relative to the material deposit ramp along the vertical axis.

[0065] According to one embodiment, the additive manufacturing device comprises a drive member for the manufacturing support capable of driving the manufacturing support in a direction of advancement.

[0066] According to one embodiment, the material deposition nozzles are arranged on the material deposition ramp in at least two rows offset along a transverse axis perpendicular to the longitudinal direction and perpendicular to the vertical direction, each row comprising at least two material deposition nozzles aligned in the longitudinal direction.

[0067] In other words, the rows are parallel to each other. During each material deposition sequence, in particular during a relative movement in the direction of advance of the material deposition ramp relative to the manufacturing support, each material deposition nozzle is configured to deposit molten material according to a thickness along at least one given material line. All of the material deposition nozzles deposit material according to a first layer corresponding to the width of the three-dimensional object to be manufactured.

[0068] After each material deposition sequence, i.e. after the manufacture of each layer of material, the transverse position of the manufacturing support is reset and a relative movement along the vertical axis of the material deposition ramp with respect to the manufacturing support is generated in order to vertically move said ramp away from said support. Then, each of the material deposition nozzles is actuated to deposit molten material along the same given transverse line of material, to form the second layer. These operations are repeated until the desired thickness of the object to be manufactured is obtained. It could be provided that the means for closing certain nozzles is in the closed position in order to produce a particular geometric shape. Again, it may also be envisaged not to reset the position of the manufacturing support and to deposit material on the next deposited layer of material in the opposite direction.

[0069] Here again, it can be provided that the material deposit ramp is movable in translation relative to the manufacturing support along the vertical axis or, alternatively, that it is the manufacturing support which is movable in translation relative to the material deposit ramp along the vertical axis.

[0070] Generally, the number of rows depends on the width of the three-dimensional object to be manufactured.

[0071] According to one embodiment, the width of the material deposit ramp is less than the width of the three-dimensional object to be manufactured.

[0072] In this case, during each material depositing sequence, and in particular during the relative movement in the direction of advance of the material depositing ramp relative to the manufacturing support, each material depositing nozzle is configured to deposit material over a thickness along a given material line and after each thickness manufacturing along a given transverse material line and the material depositing ramp is configured to be in translation relative to the manufacturing support axially along the longitudinal axis of the width of said ramp, as many times as necessary to manufacture the first layer comprising all of the material lines. These operations are repeated until all of the superimposed layers forming the desired thickness of the object to be manufactured are obtained.

[0073] According to another variant, it could be provided that the width of the material depositing ramp is equal to or even greater than the width of the three-dimensional object to be manufactured, but that the density of material depositing nozzles is reduced in order to reduce costs. In this case, after each material sequence, that is to say after each nozzle deposits material along a given line, the material depositing ramp is configured to be axially offset in translation relative to the manufacturing support along the longitudinal axis by the width of a material depositing nozzle as many times as necessary to produce the first layer comprising all the lines of material. Here again, each material depositing nozzle is configured to deposit material on several lines of material during several material depositing sequences.

[0074] According to one embodiment, the material depositing nozzles are arranged in the same plane containing a longitudinal axis, said nozzles being vertically offset relative to each other.

[0075] In this case, at least one of the material deposition nozzles can be configured to deposit material on all the circumferential lines of an entire material layer during several material deposition sequences and the material deposition ramp is configured to move only axially in translation relative to the manufacturing support along the longitudinal axis of a material line after each material deposition sequence. The number of material deposition nozzles this time depends on the number of layers to be printed.

[0076] In this case, at least one of the material deposition nozzles of the material deposition ramp is configured to deposit material on a material line of a first material layer. After each material deposition sequence, the material deposition ramp is configured to be moved only axially in translation relative to the manufacturing support along the longitudinal axis of a material line. These operations are repeated until at least one of the material deposition nozzles deposits material on an entire first material layer comprising all of the material lines.

[0077] Then, the adjacent nozzle is configured to deposit material on a material line of a second layer of material superimposed on the first layer. These operations are repeated until the desired thickness of the object to be manufactured is obtained.

[0078] The nozzles are for example actuated simultaneously to deposit material along a material line onto the lower material line, then the material depositing ramp is configured to move axially in translation relative to the manufacturing support along the longitudinal axis of a circumferential material line after each material depositing sequence, so that the material depositing nozzles manufacture the adjacent material line and so on until the desired geometry of the three-dimensional object is obtained.

[0079] According to another embodiment, the device for additive manufacturing of an object comprises two material depositing ramps each associated with a specific actuation system, said ramps being movable in translation in the longitudinal direction in two opposite directions. The two material depositing ramps are configured to deposit a single layer of material together.

[0080] According to one embodiment, the device comprises a drive member of the manufacturing support capable of driving the manufacturing support in a direction of advancement. According to one embodiment, the actuation system is configured to move the material depositing ramp in translation relative to the manufacturing support in a vertical direction and / or the longitudinal direction.

[0081] According to a second aspect, the invention relates to a method for additive manufacturing of all or part of a three-dimensional object on a manufacturing support by a manufacturing device comprising at least one material deposit ramp arranged above the manufacturing support, extending along an extension axis, here a longitudinal axis and comprising a plurality of nozzles for depositing material by addition, each provided with at least one distribution orifice, in which:

[0082] - each of the material deposition nozzles deposits extruded material onto the manufacturing support during a material deposition sequence,

[0083] - closing means each associated with one of the material depositing nozzles are controlled independently of each other to be moved between a closing position and a plurality of opening positions of the distribution orifice of each nozzle according to the geometries of the three-dimensional object to be manufactured, and

[0084] - after each material deposit sequence, the material deposit ramp and the manufacturing support having a relative movement with respect to each other in translation in at least one vertical direction and / or one longitudinal direction.

[0085] According to one embodiment, during each material deposition sequence, the manufacturing support is moved in translation relative to the material deposition ramp along the transverse axis between an initial position and a final position and returns to its initial position at the end of each material deposition sequence. Alternatively, it is also possible to envisage not returning to the initial position to deposit material on the next layer but starting it at the final position of the previous layer and creating the layer in the reverse direction. This saves time and does not require time to return to the initial position.

[0086] During each material deposition sequence, each material deposition nozzle deposits material along a thickness of at least one given material line, and all of the material deposition nozzles deposit material along a first layer corresponding to the width of the three-dimensional object to be manufactured, and wherein, after each material deposition sequence, the material deposition ramp is moved in translation relative to the manufacturing support along the vertical axis and each of the material deposition nozzles deposits material along the same given material line, to form a second layer superimposed on the first layer. These operations are repeated until the desired thickness of the three-dimensional object is obtained.

[0087] Thus, a whole layer is produced at each material deposition sequence.

[0088] The material deposit ramp can be moved in translation relative to the manufacturing support along the vertical axis. Alternatively, the material deposit ramp can be fixed relative to the base of the manufacturing device and it is the manufacturing support which is moved in translation relative to the material deposit ramp along the vertical axis.

[0089] According to one embodiment, the width of the material depositing ramp is less than the width of the tread to be manufactured. During each material depositing sequence, each material depositing nozzle deposits material over a thickness along a given material line. Said material depositing ramp is moved in translation relative to the tire axially along the longitudinal axis of the width of said ramp after each material depositing sequence. These operations are repeated until the first layer of material comprising all of the material lines is obtained.

[0090] The material deposition ramp can be moved in translation relative to the manufacturing support along the longitudinal axis. Alternatively, the material deposition ramp can be fixed relative to the base of the manufacturing device and it is the manufacturing support which is moved in translation relative to the material deposition ramp along the longitudinal axis. Thus, each material deposition nozzle deposits material on several lines of material during several material deposition sequences. Then, the manufacturing support is moved in translation relative to the material deposition ramp along the transverse axis in its initial position and the material deposition ramp is moved in translation vertically relative to the manufacturing support to create the second layer and so on until the desired thickness of the three-dimensional object is obtained.

[0091] According to another variant, it could be provided that the width of the material depositing ramp is equal to or greater than the width of the three-dimensional object to be manufactured, but that the density of material depositing nozzles is reduced in order to reduce costs. In this case, after each material depositing sequence, the material depositing ramp is axially offset in translation relative to the manufacturing support along the longitudinal axis by the width of a material depositing nozzle as many times as necessary to produce the first layer comprising all the lines of material. Here again, each material depositing nozzle deposits material on several lines of material during several material depositing sequences.

[0092] According to another embodiment, in which the width of the material depositing ramp is equal to the width of the three-dimensional object to be manufactured, during each material depositing sequence, at least one of the material depositing nozzles on a circumferential line of material of an entire layer of material. After each material depositing sequence, the manufacturing support is moved in translation relative to the material depositing ramp along the transverse axis in its initial position and the material depositing ramp is moved only axially in translation relative to the manufacturing support along the longitudinal axis of a line of material. These operations are repeated until at least one of the material depositing nozzles deposits material on an entire layer of material comprising all of the lines of material.

[0093] The number of material deposition nozzles depends this time on the number of layers to be printed. In this case, during a material deposition sequence, the nozzles are actuated simultaneously to deposit material along a material line on the lower material line, then the material deposition ramp is moved axially in translation relative to the manufacturing support along the longitudinal axis of a material line after each material deposition sequence, so that the material deposition nozzles deposit material along the adjacent material line and so on until the desired three-dimensional object is obtained.

[0094] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0095] [Fig 1] very schematically represents a device for additive manufacturing of a tread according to the invention configured to manufacture a tread on a tire of a wheel according to a first exemplary embodiment;

[0096] [Fig 2] illustrates another example of a wheel on which the additive manufacturing device of Figure 1 can be used;

[0097] [Fig 3] illustrates a detail of a material deposition nozzle of the additive manufacturing device of FIG. 1 comprising a temporary sealing system according to one embodiment;

[0098] [Fig 4], [Fig 5] schematically represent in detail the additive manufacturing device for a tread of figure 1 according to a first embodiment of the invention;

[0099] [Fig 6], [Fig 7] schematically represent in detail the device for additive manufacturing of a tread of figure 1 according to a second embodiment of the invention; [Fig 8], [Fig 9] schematically represent in detail the device for additive manufacturing of a tread of figure 1 according to a third embodiment of the invention;

[0100] [Fig 10], [Fig 11] schematically represent in detail the additive manufacturing device for a tread of FIG. 1 according to a fourth embodiment of the invention;

[0101] [Fig 12] schematically represents in detail the additive manufacturing device for a tread of figure 1 according to a fifth embodiment of the invention; and

[0102] [Fig 13] illustrates another example of a support on which the additive manufacturing device of Figure 1 can be used.

[0103] In the remainder of the description, we consider an orthonormal basis X, Y, Z, defined with respect to the additive manufacturing device 10 in which we find:

[0104] - a longitudinal axis X, horizontal and extending from back to front in figure 1;

[0105] - a transverse axis Y, horizontal, perpendicular to the longitudinal axis X and extending from left to right in figure 1; and

[0106] - a vertical axis Z, orthogonal to the longitudinal axes X and transverse Y and extending from bottom to top in figure 1.

[0107] As illustrated in Figure 1, a mounted assembly 1 or wheel comprises a rim 2 comprising a fixing hub 3 and a tire 4 or pneumatic bandage mounted on the rim 2. The tire 4 comprises a tread-bearing surface 5, a tread 6 and two lateral sidewalls 7 surrounding the tread-bearing surface 5 on either side, only one of which is visible in Figure 1.

[0108] The rim 2 is preferably the final rim intended to be mounted on a motor vehicle. The fixing hub 3 forms the fixing interface between the wheel 1 and the vehicle.

[0109] The fixing hub 3 here defines a hollow fixing cylinder in which a wheel axle (not referenced) can be housed.

[0110] The tire 4 is here subjected to an internal pressure by means of an inner tube (not shown) inflated to a recommended nominal inflation pressure or lower.

[0111] Alternatively, the mounted assembly 1 could be a tubeless wheel comprising an insert (not shown) made up of several layers of expanded plastic to replace the inner tube.

[0112] The mounted assembly 1 could also be a so-called “airless” tire.

[0113] The tread 6 comprises two lateral surfaces (not referenced), an internal surface (not visible) integral with the tread bearing surface 5 and a rolling surface 6a opposite the internal surface and intended to come into contact with a road surface S when the wheel 1 rolls.

[0114] The tread 6 comprises a plurality of cutouts or sculptures extending on at least one of its lateral surfaces.

[0115] Rim 2 here forms a radial load-bearing structure for tire 4.

[0116] As illustrated in FIG. 1, a device 10 for additively manufacturing a tread 6 is configured to deposit an extruded material forming the tread 6 on a load-bearing circumferential surface 5 of the tire 4 of the wheel 1.

[0117] Generally, the device 10 for additively manufacturing a tread 6 is configured to deposit an extruded material forming the tread 6 on a tire 4. Indeed, it would be possible to provide for the manufacturing of the tread 6 on a tire 4 not mounted on a wheel.

[0118] It would also be possible to provide for the reloading of a new tread 6 onto a worn tread. In this case, the bearing surface corresponds to the worn tread. By "tire" is meant all types of elastic bandages of toric shape subjected to internal pressure or not.

[0119] By "tread" of a tire is meant a quantity of rubber material delimited by lateral surfaces and by two main surfaces, one of which is called the rolling surface, intended to come into contact with a road surface when the tire is rolling. The tread comprises a plurality of cutouts or sculptures extending on at least one of the lateral surfaces.

[0120] The "sidewall" of a tire means a portion of the lateral surface of the tire disposed between the tire tread and a supporting structure of the wheel. In the case of a tire of a conventional wheel, the sidewall begins from the ends of the tread cutouts and extends to a bead of the tire.

[0121] The additive manufacturing device 10 comprises a fixed base 12 and one or more material depositing ramps 20, 30 mounted in translation relative to said fixed base 12.

[0122] In a non-limiting manner, the fixed base 12 comprises a base 14 fixed to the ground S and a vertical arm 16 for fixing the material depositing ramp 20, 30.

[0123] The material deposit ramp 20, 30 is arranged above the wheel 1, and in particular the tread of the tire 4.

[0124] The ramp 20, 30 extends along an extension axis, here the longitudinal axis X.

[0125] The additive manufacturing device 10 comprises an extruder 18 connected to the material depositing ramp 20, 30 and is configured to produce a rod of molten material, for example from granules of material, preferably made of plastic material, for example thermoplastic elastomer, with the acronym TPE. The granules of material are therefore extruded hot.

[0126] The molten rod is continuous.

[0127] The extruder 18 is here central and feeds said ramp 20, 30 with a rod of molten material from granules. In other words, the central extruder is associated with all of the material depositing nozzles. Alternatively, a different arrangement than central could be provided for the single extruder.

[0128] Alternatively, the central extruder 18 feeds said ramp 20, 30 with a rod of molten material from one or more filaments, or even strips.

[0129] Alternatively, at least one extruder could be provided associated with at least one material depositing nozzle.

[0130] For example, several extruders could be provided, each associated with at least two material depositing nozzles.

[0131] The tread 6 is manufactured by depositing the extruded material layer by layer on the bearing surface 5 of the tire 4. The extruded material melts on the layer of material deposited previously and solidifies when the temperature drops.

[0132] For this purpose, the material depositing ramp 20, 30 comprises a plurality of nozzles 21, 22, 23, 24; 31, 32, 33, 34, 35, 36, 37, 38 which will be described in detail with reference to FIGS. 3 to 12. Each of the nozzles is configured to deposit the molten material on the carrier surface 5 of the tire 4 mobile in rotation around a horizontal axis of rotation XX.

[0133] Additive manufacturing on a support, here the bearing surface 5 of the tire 4, or more generally the tire 4, placed in continuous rotation makes it possible to manufacture or completely reconstitute the tread 6 over its entire circumference.

[0134] "Continuous rotation" means rotation in one direction only, without interruption and at a constant speed.

[0135] “Discontinuous rotation” means rotation in a single direction at variable speed during material deposition.

[0136] For this purpose, the additive manufacturing device 10 comprises a member 15 for driving the tire 4 in rotation around the axis of rotation XX.

[0137] As illustrated in Figure 1, the rotation drive member 15 is in the form of a rotating drum or cylinder cooperating with the wheel hub 3 and configured to drive the tire 4 in rotation via the wheel hub 3.

[0138] Alternatively, it could be provided that the rotation drive member comprises rollers arranged under the wheel to rotate said wheel by friction in the case of a tire mounted on a wheel.

[0139] According to another variant, a rotation drive member could be provided configured to act directly on the sidewalls 7 of the tire 4.

[0140] These variants are interesting in the case where it is necessary to manufacture the tread 2 without removing the wheel 1 from the vehicle.

[0141] The additive manufacturing device 10 further comprises an actuation system (not shown) configured to move the material depositing ramp 20, 30 relative to the wheel 1 in a vertical direction Z and / or a longitudinal direction X parallel to the axis of rotation XX along the width of the wheel 1. Thus, all of the nozzles are moved simultaneously at the same time as the movement of the material depositing ramp 20, 30.

[0142] The device 10 for additively manufacturing a tread can also be used to manufacture or refill a tread 6' on a bearing surface 5' of a tire 4' of a full wheel 1' as illustrated in FIG. 2.

[0143] The integral wheel 1' here comprises a radial supporting structure 2' around which is fixed a tire 4' or solid bandage comprising a support 7' radially external to the supporting structure 2'. The support 7' extends over the entire circumference of the supporting structure 2' and carries the tread 6'. The tread 6' is here structurally integrated with the support 7' by means of a tread-bearing surface 5' forming a peripheral external contour of the radial supporting structure 2'.

[0144] The 4' solid bandage is not subject to internal pressure.

[0145] As illustrated in Figure 2, the radial supporting structure 2' comprises a fixing hub 3' for fixing the wheel 1' to a vehicle. The fixing hub 3' here defines a hollow fixing cylinder in which a wheel axle (not shown) can be housed.

[0146] The radial supporting structure 2' is, for example, made of glass fiber reinforced plastic material.

[0147] The supporting structure 2' here comprises a plurality of sticks or stays 8' connecting the hub 3' to the support 7'.

[0148] As illustrated in Figure 2, the supporting structure 2' comprises five sticks 8'. Alternatively, a number of sticks 8' between three and nine could be provided.

[0149] 9' openings or windows are defined between two adjacent 8' sticks. The 9' openings are here regularly distributed circumferentially.

[0150] The 9' openings here have ovoid profiles. Alternatively, other profile shapes could be provided for the 9' openings.

[0151] The supporting structure 2' and the support 7' here comprise a network or a three-dimensional structure of beams or lattices.

[0152] Alternatively, it could be provided that the radial supporting structure 2' comprises a plurality of slats arranged radially to support the tire 4' and in particular the support 7'.

[0153] As illustrated in Figure 3, each material depositing nozzle or jet 21, 22, 23, 24; 31, 32, 33, 34, 35, 36, 37, 38 comprises a chamber 25 for receiving the molten material coming from the central extruder 18 and a distribution orifice 26 in communication with the chamber 25.

[0154] The dispensing orifice 26 has a dimension between 0.6 mm and 1.5 mm, preferably between 0.6 mm and 0.8 mm to produce a deposit of material 1 mm wide and preferably between 1 mm and 1.5 mm to produce a deposit of material 2 mm wide.

[0155] The distribution orifice 26 of each of the nozzles has a rectangular or circular section. A rectangular section makes it possible to improve the level of detail of the sculpture and the quality of the interruptions.

[0156] Each of the material depositing nozzles 21 to 24; 31 to 38 comprises a closure device 28 comprising a closure means 28a movable between a closure position and an opening position of the dispensing orifice 26, and an actuator 28b for controlling the movement of the closure means 28a between the closure and opening positions. The closure means 28a can be controlled independently of one another.

[0157] Thus, each nozzle comprises its own shut-off means 28 configured to interrupt the flow of molten material through the dispensing orifice 26 of the corresponding nozzle.

[0158] Each of the nozzles can be interrupted independently and reactively, so as to generate any sculpture or geometry on the wheel 1 and in a short time, preferably less than 20 min, preferably less than 15 min.

[0159] Such a loading time corresponds to a material deposit rate of between 10kg / h and 20kg / h, preferably equal to 12kg / h.

[0160] The shutter frequency is between 10Hz and 30Hz, for example equal to 20Hz.

[0161] In the example illustrated in Figure 3, the closure means 28a is in the form of a needle actuated by the actuator 28b.

[0162] The actuator 28b comprises, for example, a piezoelectric device (not shown) for closing or opening the dispensing orifice 26 of the corresponding nozzle.

[0163] The needle shutter 28a makes it possible to achieve clean stops in the flow of molten material, without burrs, and clean restarts of said flow.

[0164] Alternatively, any other means of closure associated with each of the nozzles could be provided, such as for example a valve.

[0165] According to a non-limiting example, the additive manufacturing device 10 may comprise a volumetric dosing device (not shown) arranged downstream of the central extruder and upstream of the material deposit ramp 20, 30.

[0166] For example, the volumetric metering device is a gear pump. The volumetric metering device is configured to deposit a calibrated quantity of molten material onto the bearing surface 5, 5' of the tire 4, 4'. Thus, lines of material of constant width can be obtained, unlike the deposit of material in the form of successions of droplets known from the prior art.

[0167] The terms “downstream” and “upstream” are defined by considering the direction of circulation of the material.

[0168] An example of a material depositing ramp 20 is illustrated with reference to Figures 4 and 5.

[0169] In this example, the material depositing ramp 20 is configured to deposit extruded material forming the tread 6, 6' on the tire 4, 4', in particular its circumferential bearing surface 5, 5', along circumferential lines of material Li.

[0170] By deposition of material along a “circumferential line of material” Li, we mean the deposition of material along a circular trajectory of the tire 4, 4', with i ranging from 1 to x, x being the total number of lines of material.

[0171] By "layer of material" Cj is meant all the circumferential or transverse lines of material Li side by side across the entire width of the tread 6, 6' to be manufactured, with j ranging from 1 to y, y being the total number of layers of material to form the total thickness of the desired tread 6, 6'.

[0172] A layer of material C corresponds to a thickness of molten material deposit.

[0173] By "row" R is meant an arrangement along the longitudinal axis X parallel to the axis of rotation XX of the tire 4, 4' and perpendicular to the vertical direction Z. A row R is arranged along the width of the tire 4, 4', in particular its bearing surface 5, 5'.

[0174] As illustrated in Figures 4 and 5, the material depositing ramp 20 comprises a plurality of material depositing nozzles 21, 22, 23, 24, here twenty-four in number, each intended to construct all the thicknesses or layers of at least one circumferential line of material Li.

[0175] By "thickness" we mean a layer of material deposited on a material line. As illustrated, the number of material depositing nozzles is, here, twenty-four and the number of material lines Li is here equal to twenty-four. We therefore have i between one and twenty-four.

[0176] Alternatively, a different number of material depositing nozzles could be provided.

[0177] As illustrated, the number of layers of matter Cj is, here, six. We therefore have j between one and six.

[0178] Alternatively, one could provide a different number of layers of material Cj .

[0179] As illustrated, the material depositing ramp 20 has a width at least equal to the width of the tread 6, 6' to be manufactured.

[0180] During the continuous rotation of the tire 4,4' under the material depositing ramp 20, each of the material depositing nozzles is actuated to deposit material on a given circumferential line of material Li. The first nozzle 24 deposits material on a first line L1, the second nozzle 23, adjacent to the first nozzle 24, simultaneously deposits material on a second line L2, adjacent to the first line L1 and so on until the entire layer comprising all of the adjacent circumferential lines Li is produced.

[0181] Thus, a full layer is produced at each complete rotation of the tire 4, 4'. After each complete rotation of the tire, the material depositing ramp 20 is moved in translation relative to the tire 4, 4' along the vertical axis Z and each of the material depositing nozzles 21, 22, 23, 24 is actuated to deposit molten material along the same circumferential line of given material Li, to form the second layer. These operations are repeated until the desired thickness of the tread 6, 6' is obtained.

[0182] In the example illustrated in Figures 4 and 5, a single material deposition nozzle 21, 22, 23, 24 is configured to construct all the thicknesses of a given circumferential line of material Li. The material deposition nozzles 21, 22, 23, 24 are here arranged on the material deposition ramp 20 in rows RI, R2, R3, R4 offset along the transverse axis Y.

[0183] In fact, it may be necessary to provide a distance of 4mm between each material depositing nozzle.

[0184] As illustrated, the material depositing ramp comprises four rows R1, R2, R3, R4 each comprising six material depositing nozzles 21, 22, 23, 24. Alternatively, a different number of rows could be provided, for example greater than or equal to two. A different number of nozzles could also be provided per row R.

[0185] The number of rows R depends on the width of the tread 6, 6' to be manufactured.

[0186] Alternatively, it could also be provided that the material depositing nozzles 21, 22, 23, 24 are arranged on the material depositing ramp 20 in a single row RI in the longitudinal direction X.

[0187] Alternatively, it could be provided that the material depositing ramp 20 has a width different from the tread 6, 6' to be manufactured.

[0188] For example, it could be provided that the material depositing ramp 20 has a width less than the width of the tread 6, 6' to be manufactured. In this case, during each complete rotation of the tire 4, 4', each material depositing nozzle 21 to 24 deposits material over a thickness along a given circumferential line of material Li and after each complete revolution of the tire 4, 4', the material depositing ramp 20 is moved in translation relative to the tire 4, 4' axially along the longitudinal axis X by the width of said ramp 20, as many times as necessary to manufacture the first layer comprising all of the lines of material Li. After the manufacture of each layer comprising all of the lines of material Li, the material depositing ramp 20 is moved in translation relative to the tire 4, 4' along the vertical axis Z and the operation of manufacturing a layer is repeated.These operations are repeated until all the superimposed layers forming the desired thickness of the tread 6, 6' are obtained.

[0189] For example, for a bearing surface 5.5' having a width of 225mm, and a material depositing ramp 20 of 80mm width, the tire 4.4' is rotated over three complete revolutions and during each complete revolution, the material depositing ramp 20 is offset along the longitudinal axis X by 80mm.

[0190] Thus, each material depositing nozzle 21, 22, 23, 24 deposits material on several circumferential lines of given material Li during several complete revolutions of the tire 4, 4'.

[0191] According to another variant, it could be provided that the width of the material depositing ramp 20 is equal to or greater than the width of the tread 5, 5' to be manufactured, or more generally than the width of the bearing surface 5, 5', but that the density of material depositing nozzles is reduced in order to reduce costs. In this case, after each complete revolution of the tire 4, 4', the material depositing ramp 20 is offset in translation axially relative to the tire 4, 4' along the longitudinal axis X by the width of a material depositing nozzle 21, 22, 23, 24 as many times as necessary to produce the first layer C1 comprising all of the lines of material Li. After the manufacture of each layer comprising all of the lines of material Li, the material depositing ramp 20 is moved in translation relative to the tire 4, 4' along the vertical axis Z and the operation of manufacturing a layer is repeated.

[0192] These operations are repeated until all the superimposed layers forming the desired thickness of the tread 6, 6' are obtained.

[0193] Again, each material depositing nozzle deposits material on several lines of material during several complete revolutions of the tire 4, 4'.

[0194] However, such a variant increases the total manufacturing time of the tread. Tl

[0195] As illustrated, the additive manufacturing device 10 comprises a single material deposit ramp 20 around the tire 4, 4'.

[0196] Alternatively, it could be provided that the additive manufacturing device 10 comprises at least two material depositing ramps 20 each associated with a specific actuation system and arranged circumferentially around the tire at two given azimuths.

[0197] For example, a first ramp could be provided at a given first azimuth and a second ramp arranged at 180° from the first ramp. Alternatively, the second ramp could be arranged relative to the first ramp at an angle of between 10° and 350°, preferably between 30° and 320°.

[0198] Alternatively, a different number of ramps could be provided, for example greater than or equal to three, each associated with its own actuation system and arranged circumferentially around the tire at three given azimuths.

[0199] Another example of a material depositing ramp 30 is illustrated with reference to Figures 6 and 7.

[0200] In this example, the material depositing ramp 30 is configured to deposit extruded material forming the tread 6, 6' on the tire 4, 4', in particular its circumferential bearing surface 5, 5', in layers of material Cj.

[0201] In this example, the width of the material depositing ramp 30, 30a, 30b is equal to the width of the tread 6, 6' to be manufactured and each material depositing nozzle 31 to 38 is configured to build an entire material layer Cj.

[0202] During each complete rotation of the tire, one of the material depositing nozzles of the material depositing ramp 30 deposits material on a circumferential line of material Li of a layer of material Cj. After each complete rotation of the tire 4, 4', the material depositing ramp 30 is moved in translation only axially relative to the tire 4, 4' along the longitudinal axis X of a line of material Li. These operations are repeated until each material depositing nozzle 31 to 38 deposits material on an entire layer of material Cj comprising all of the lines of material Li.

[0203] In other words, during a complete rotation of the tire 4, 4', the nozzles 31 to 38 are actuated successively to produce a given circumferential line of material Li. The first nozzle 31 deposits material on a first line L8 according to a first thickness, then the material depositing ramp 30 is moved axially relative to the tire 4, 4' along the longitudinal axis X by the width of a line of material Li, the first nozzle 31 deposits material on a second line L7 and the second nozzle 32, adjacent to the first nozzle 31, deposits material on the first line L8 according to a second layer thickness superimposed on the first line formed by the first nozzle and so on until each material depositing nozzle produces a given layer Cj until the desired tread pattern 6, 6' is obtained.

[0204] Thus, the first material deposition nozzle 31 produces the first layer C1, the second nozzle 32 produces the second layer C2, the third nozzle 33 produces the third layer C3, and so on until the desired total thickness of the tread 6, 6' is obtained. Each of the material deposition nozzles 31 to 38 is therefore configured to build up an entire material layer Cj.

[0205] The Cj layers are built in this way with a one-turn delay on the previous layer.

[0206] Such an arrangement allows the use of fewer material deposition nozzles than material deposition with nozzles configured to deposit material along a material line Li.

[0207] In this embodiment, the material depositing ramp 30 is not moved in translation along the vertical axis Z.

[0208] The number of material depositing nozzles 31 to 38 depends this time on the number of layers of material to be built.

[0209] The material deposition nozzles 31 to 38 are here arranged in rows RI, R2, R3, R4 offset along the vertical axis Z.

[0210] Indeed, it may be necessary to provide a distance of 4 mm between each material deposition nozzle. As illustrated, the material deposition ramp comprises eight material deposition nozzles 31 to 38. Alternatively, a different number of material deposition nozzles could be provided, for example greater than or equal to six.

[0211] As illustrated, the number of material lines Li is equal to eight. Alternatively, a different number of material lines Li could be provided. The number of material lines depends on the width of the tread 6, 6' to be produced.

[0212] As illustrated, the number of layers of material Cj is equal to eight. Alternatively, a different number of layers of material Cj could be provided. The number of layers of material Cj depends on the total thickness of the tread 6, 6' to be manufactured.

[0213] Taking for example a layer thickness Cj of 0.8mm for 8mm of total thickness of the tread to be manufactured, ten material deposition nozzles can be used.

[0214] However, the rotational speed of the tire 4, 4' and the frequency of closing of the nozzles are higher than with nozzles configured to deposit the material along a material line Li, as described in detail with reference to figures 3 and 4.

[0215] In the example illustrated in Figures 6 and 7, the material depositing nozzles 31 to 38 deposit material on the same material line Li with an offset along the longitudinal axis X.

[0216] As illustrated, the nozzles 31 to 38 are also offset along the vertical axis Z, so that it is no longer necessary to move the material depositing ramp vertically relative to the tire 4, 4'.

[0217] The embodiment illustrated in Figures 8 and 9 in which the same elements bear the same references, differs from the embodiment illustrated in Figures 6 and 7 only in that the layers Cj are constructed with two turns of delay on the previous layer.

[0218] As illustrated in Figures 8 and 9, the material depositing ramp 30 comprises eight material depositing nozzles 31 to 38. Alternatively, a different number of material depositing nozzles could be provided, for example greater than or equal to six.

[0219] As illustrated, the number of material lines is equal to fifteen Li. Alternatively, a different number of material lines Li could be provided. The number of material lines depends on the width of the tread 6, 6' to be produced.

[0220] As illustrated, the number of layers of material Cj is equal to eight. Alternatively, a different number of layers of material Cj could be provided. The number of layers of material Cj depends on the total thickness of the tread 6, 6' to be manufactured.

[0221] The embodiment illustrated in Figures 10 and 11 in which the same elements have the same references, differs from the embodiment illustrated in Figures 8 and 9 only in that two material depositing nozzles 31a, 31b to 38a, 38b are configured to build up an entire layer of material comprising all of the adjacent circumferential lines Li over a thickness. The layers of material Cj are built up with two turns of delay on the previous layer.

[0222] As illustrated in Figures 10 and 11, the material depositing ramp 30 comprises sixteen material depositing nozzles 31a, 31b to 38a, 38b. Alternatively, a different number of material depositing nozzles could be provided, for example greater than or equal to eight.

[0223] As illustrated, the number of lines of material is equal to twenty-three. Alternatively, a different number of lines of material could be provided. The number of lines of material depends on the width of the tread 6, 6' to be produced.

[0224] As illustrated, the number of layers of material Cj is equal to eight. Alternatively, a different number of layers of material Cj could be provided. The number of layers of material Cj depends on the total thickness of the tread 6, 6' to be manufactured.

[0225] The embodiment illustrated in Figure 12 in which the same elements bear the same references, differs from the embodiment illustrated in Figures 8 and 9 only by the fact that the additive manufacturing device 10 comprises two material depositing ramps 30a, 30b.

[0226] The additive manufacturing device 10 comprises a first actuation system (not shown) configured to move in translation a first material depositing ramp 30a relative to the tire 4, 4' in the longitudinal direction X parallel to the axis of rotation XX along the width of the tire 4, 4' in a first direction.

[0227] The additive manufacturing device 10 comprises a second actuation system (not shown) configured to move in translation a second material deposit ramp 30b relative to the wheel 1, 1' in the longitudinal direction X along the width of the tire 4, 4' in a second direction.

[0228] The first meaning is opposite to the second meaning.

[0229] The two material depositing ramps 30a, 30b are thus configured to be moved along the longitudinal axis X relative to the tire 4, 4' in opposite directions starting from the middle of the tire 4, 4'. The two material depositing ramps 30a, 30b are configured to deposit material together on a single layer Cj.

[0230] Each ramp 30a, 30b corresponds to one of the ramps described with reference to figures 6 to 11.

[0231] As illustrated in FIG. 12, each material depositing ramp 30a, 30b comprises eight material depositing nozzles (not referenced). Alternatively, a different number of material depositing nozzles could be provided, for example greater than or equal to six.

[0232] As illustrated, the number of material lines Li is equal to sixteen. Alternatively, a different number of material lines could be provided. The number of material lines depends on the width of the tread 6, 6' to be produced.

[0233] As illustrated, the number of layers of material Cj is equal to four. Alternatively, a different number of layers of material Cj could be provided. The number of layers of material Cj depends on the total thickness of the tread 6, 6' to be manufactured. In the embodiments illustrated in FIGS. 1 to 12, the additive manufacturing device 10 has been described for manufacturing a tread 6, 6' of a tire 4, 4'.

[0234] However, the present invention is not limited to the manufacture of a tire tread. Indeed, the additive manufacturing device 10 is configured to manufacture any type of three-dimensional objects, of cylindrical shape, or of shape other than cylindrical, for example, parallelepiped.

[0235] In this regard, reference may be made to figure 13 which illustrates a manufacturing support 104 for a three-dimensional object 106, here a rectangular parallelepiped.

[0236] The manufacturing support 104 is here in the form of a platform extending in the XY plane comprising the longitudinal axis X and the transverse axis Y. The platform 104 comprises an external supporting surface (not referenced) for receiving the successive layers Cj of extruded material coming from the ramp 20, 30 of the additive manufacturing device 10 and forming the three-dimensional object 106 manufactured.

[0237] Alternatively, a planar shape other than parallelepiped could be provided for the platform 104.

[0238] The object 106 to be manufactured can be manufactured using one or more material depositing ramps 20 described in detail with reference to FIGS. 4 and 5 or using one or more material depositing ramps 30, 30a, 30b described in detail with reference to FIGS. 6 to 11.

[0239] Generally, the manufacturing support 104 and the ramp(s) 20, 30, 30a, 30b of the additive manufacturing device 10 have a relative movement with respect to each other at least in the longitudinal direction X and / or the vertical direction Z.

[0240] The additive manufacturing device 10 comprises a drive member 15 for at least translating the manufacturing support 104 capable of driving the manufacturing support 104 in translation at least in one direction of advance, here along a transverse Y. Generally, the direction of advance of the manufacturing support 104 is perpendicular to the axis of extension, here longitudinal X, of the ramp 20, 30.

[0241] In a manner similar to the embodiments illustrated in FIGS. 4 to 11, the additive manufacturing device 10 further comprises an actuation system (not shown) configured to generate a relative translational movement of the material deposit ramp 20, 30 relative to the manufacturing support 104 in a vertical direction Z and / or a longitudinal direction X. Thus, when it is the material deposit ramp 20, 30 which is moved, all of the nozzles are moved simultaneously at the same time as the movement of the material deposit ramp 20, 30.

[0242] The longitudinal direction is here parallel to the longitudinal axis X of the ramp 20, 30 or can be confused with said longitudinal axis X.

[0243] By "width" of the object to be manufactured 106, we mean the dimension along the longitudinal axis X. The width could also be the dimension along the transverse axis Y. Generally, the width of the object to be manufactured 106 corresponds to the extension dimension, here the longitudinal axis X, of the ramp 20, 30. In the case where the object 106 is manufactured by the plurality of material depositing nozzles 21, 22, 23, 24 of the material depositing ramp 20 described in detail with reference to FIGS. 4 and 5, each of said nozzles 21 to 24 is intended to construct all the thicknesses or strata of at least one given transverse line of material Li.

[0244] According to one embodiment, the material deposit ramp 20 has a width equal to the width of the object 106 to be manufactured.

[0245] Each of the material deposition nozzles is actuated to deposit material on a given transverse line of material Li. The first nozzle 24 deposits material on a first line L1, the second nozzle 23, adjacent to the first nozzle 24, simultaneously deposits material on a second line L2, adjacent to the first line L1 and so on until the entire layer comprising all the adjacent transverse lines Li is produced. After the production of each layer Cj of material, corresponding to a material deposition sequence, the material deposition ramp 20 is moved in translation relative to the manufacturing support 104 along the vertical axis Z and each of the material deposition nozzles 21, 22, 23, 24 is actuated to deposit molten material along the same given transverse line of material Li, to form the second layer. These operations are repeated until the desired thickness of the object to be manufactured 106 is obtained.

[0246] The material deposit ramp 20 can be movable in translation relative to the manufacturing support 104 along the vertical axis Z. Alternatively, the material deposit ramp 20 can be fixed relative to the base 12 of the manufacturing device 10 and it is the manufacturing support 104 which is movable in translation relative to the material deposit ramp 20 along the vertical axis Z.

[0247] The manufacturing support 104 and the ramp 20 of the additive manufacturing device 10 advantageously have a relative movement with respect to each other also in the direction of advancement, here the transverse direction Y.

[0248] Here again, it can be provided that the material deposit ramp 20 is movable in translation relative to the manufacturing support 104 along the transverse axis Y or, as a variant, that it is the manufacturing support 104 which is movable in translation relative to the material deposit ramp 20 along the transverse axis Y.

[0249] During the relative movement in the transverse direction Y of the material deposition ramp 20 with respect to the manufacturing support 104, each of the material deposition nozzles is actuated to deposit material on a given transverse material line Li. The first nozzle 24 deposits material on a first line L1, the second nozzle 23, adjacent to the first nozzle 24, simultaneously deposits material on a second line L2, adjacent to the first line L1 and so on until the entire layer comprising all the adjacent transverse lines Li is produced.

[0250] After the manufacture of each layer Cj of material, corresponding to a material deposition sequence, the transverse position of the manufacturing support 104 is reset and a relative movement along the vertical axis Z of the material deposition ramp 20 with respect to the manufacturing support 104 is generated in order to vertically move said ramp 20 away from said support 104. Then, each of the material deposition nozzles 21, 22, 23, 24 is actuated to deposit molten material along the same given transverse line of material Li, to form the second layer. These operations are repeated until the desired thickness of the object to be manufactured 106 is obtained.

[0251] Here again, it can be provided that the material deposit ramp 20 is movable in translation relative to the manufacturing support 104 along the vertical axis Z or, as a variant, that it is the manufacturing support 104 which is movable in translation relative to the material deposit ramp 20 along the vertical axis Z.

[0252] In other words, during each material deposition sequence, the manufacturing support is moved in translation relative to the material deposition ramp along the transverse axis between an initial position and a final position and returns to its initial position at the end of each material deposition sequence.

[0253] Alternatively, one can also consider not resetting the build support position and depositing material on the next deposited material layer in the opposite direction.

[0254] Indeed, we can consider not returning to the initial position to deposit material on the next layer but starting it at the final position of the previous layer and creating the layer in reverse order. This saves time and does not require time to return to the initial position.

[0255] According to another embodiment, the material deposit ramp 20 has a width less than the width of the object 106 to be manufactured.

[0256] In this case, during the relative movement in the transverse direction Y of the material depositing ramp 20 with respect to the manufacturing support 104, each material depositing nozzle 21 to 24 deposits material over a thickness along a given transverse material line Li and after each thickness manufacturing along a given transverse material line Li, corresponding to a material depositing sequence, and the material depositing ramp 20 is moved in translation with respect to the manufacturing support 104 axially along the longitudinal axis X by the width of said ramp 20, as many times as necessary to manufacture the first layer comprising all the material lines Li. These operations are repeated until all the superimposed layers forming the desired thickness of the object to be manufactured 106 are obtained.

[0257] Thus, a whole layer is produced at each material deposition sequence.

[0258] After the manufacture of each layer Cj of material, corresponding to a material deposition sequence, the transverse position of the manufacturing support 104 is reset and a relative movement along the vertical axis Z of the material deposition ramp 20 relative to the manufacturing support 104 is generated in order to vertically move said ramp 20 away from said support 104 and the operation of manufacturing a layer is repeated.

[0259] By "initial transverse position" of the manufacturing support 104 is meant the first transverse position of the manufacturing support 104 relative to the material deposit ramp 20, 30 in which material is deposited for the first time on said manufacturing support 104.

[0260] In the case where the object 106 is manufactured by the plurality of material deposition nozzles 31 to 38 of the material deposition ramp 30 described in detail with reference to FIGS. 6 and 7, the width of the material deposition ramp 30, 30a, 30b is equal to the width of the object to be manufactured 106 and each material deposition nozzle 31 to 38 is configured to build an entire material layer Cj.

[0261] During a relative movement in the direction of advance, here the transverse direction Y, of the material deposition ramp 30 relative to the manufacturing support 104, one of the material deposition nozzles of the material deposition ramp 30 deposits material on a transverse material line Li of a material layer Cj and, after each material deposition sequence, the material deposition ramp 30 is moved in translation axially relative to the manufacturing support 104 along the longitudinal axis X of a material line Li and the manufacturing support 104 is moved into its initial transverse position. These operations are repeated until each material deposition nozzle 31 to 38 deposits material on an entire material layer Cj comprising all of the transverse material lines Li.

[0262] It may be provided that the material deposit ramp 30 is movable in translation relative to the manufacturing support 104 along the axis of advance, here the transverse axis Y, or, as a variant, that it is the manufacturing support 104 which is movable in translation relative to the material deposit ramp 30 along the axis of advance, here the transverse axis Y.

[0263] It may be provided that the material deposit ramp 30 is movable in translation relative to the manufacturing support 104 along the longitudinal axis X or, as a variant, that it is the manufacturing support 104 which is movable in translation relative to the material deposit ramp 30 along the longitudinal axis X.

[0264] In other words, during a relative movement in the direction of advance, here the transverse direction Y, of the material depositing ramp 30 relative to the manufacturing support 104, the nozzles 31 to 38 are actuated successively to manufacture a given transverse line of material Li.The first nozzle 31 deposits material on a first line L8 according to a first thickness, corresponding to a first material deposition sequence, then the material deposition ramp 30 is moved axially relative to the manufacturing support 104 along the longitudinal axis X by the width of a material line Li, the first nozzle 31 deposits material on a second line L7 and the second nozzle 32, adjacent to the first nozzle 31, deposits material on the first line L8 according to a second layer thickness superimposed on the first line formed by the first nozzle, corresponding to a second material deposition sequence, and so on until each material deposition nozzle manufactures a given layer Cj until the desired geometry of the object to be manufactured 106 is obtained.

[0265] Thus, the first material deposition nozzle 31 produces the first layer C1, the second nozzle 32 produces the second layer C2, the third nozzle 33 produces the third layer C3, and so on until the desired total thickness of the object to be manufactured 106 is obtained. Each of the material deposition nozzles 31 to 38 is therefore configured to construct an entire material layer Cj.

[0266] After each material deposition sequence, the manufacturing support is moved in translation relative to the material deposition ramp along the transverse axis in its initial position.

[0267] Such an arrangement allows the use of fewer material deposition nozzles than material deposition with nozzles configured to deposit material along a material line Li.

[0268] The number of material depositing nozzles 31 to 38 depends this time on the number of layers of material to be built.

[0269] The material depositing nozzles 31 to 38 are here arranged in rows RI, R2, R3, R4 offset along the vertical axis Z, so that it is no longer necessary to move the material depositing ramp 30 vertically relative to the manufacturing support 104.

[0270] In the example illustrated in Figures 6 and 7, the material depositing nozzles 31 to 38 deposit material on the same material line Li with an offset along the longitudinal axis X.

[0271] In the case where the object 106 is manufactured by the plurality of material deposition nozzles 31 to 38 of the material deposition ramp 30 described in detail with reference to FIGS. 8 and 9, the layers Cj are built with two turns of delay on the previous layer.

[0272] In the case where the object 106 is manufactured by the plurality of material deposition nozzles 31 to 38 of the material deposition ramp 30 described in detail with reference to FIGS. 10 and 11, two material deposition nozzles 31 a, 31 b to 38 a, 38 b are configured to build an entire layer of material comprising all of the adjacent transverse lines Li over a thickness. The layers of material Cj are built with two turns of delay on the previous layer. In the case where the object 106 is manufactured by the material depositing ramps 30a, 30b described in detail with reference to FIG. 12, the additive manufacturing device 10 comprises a first actuation system (not shown) configured to move in translation a first material depositing ramp 30a relative to the manufacturing support 104 in the longitudinal direction X parallel to the axis of rotation XX along the width of the manufacturing support 104 in a first direction.

[0273] The additive manufacturing device 10 comprises a second actuation system (not shown) configured to move in translation a second material deposit ramp 30b relative to the manufacturing support 104 in the longitudinal direction X in a second direction.

[0274] The first meaning is opposite to the second meaning.

[0275] The two material depositing ramps 30a, 30b are thus configured to be moved along the longitudinal axis X relative to the manufacturing support 104 in opposite directions starting from a median transverse plane of the manufacturing support 104. The two material depositing ramps 30a, 30b are configured to deposit material together on a single layer Cj.

[0276] Each ramp 30a, 30b corresponds to one of the ramps described with reference to figures 6 to 11.

[0277] Generally, the manufacturing support 104 and the ramp(s) 20, 30, 30a, 30b of the additive manufacturing device 10 have a relative movement with respect to each other at least in the longitudinal direction X and / or the vertical direction Z.

[0278] Preferably, the manufacturing support 104 is movable in translation along the axis of advancement, here the transverse axis Y.

[0279] Generally, it could be provided that the manufacturing support 104 is movable relative to the ramp 20, 30 of the additive manufacturing device 10 along one to three axes of movement, namely the vertical axis Z, the longitudinal axis X and the transverse axis Y.

[0280] Alternatively, provision could be made for the manufacturing support 104 to be fixed relative to the base 12 of the manufacturing device 10. In the case where the manufacturing support 104 is movable at least along the vertical axis Z and / or along the longitudinal axis X, the ramp 20, 30 of the additive manufacturing device 10 may be fixed relative to the fixed base 12 of said device 10. In all embodiments, provision could also be made for the manufacturing platform 104 to be movable relative to the ramp 20, 30, 30a, 30b along one to three axes of rotation A, B, C defined respectively around the axes X, Y and Z.

[0281] In all embodiments, it could be provided that the means for closing certain nozzles is in the closed position in order to produce a particular geometric shape of the object to be manufactured.

[0282] The multi-nozzle material deposition ramp allows the deposition of material at selected locations and thus to achieve good quality geometry of the three-dimensional object, namely a tread, a cylindrical object or any other object, for example of parallelepiped shape.

Claims

CLAIMS 1. Device (10) for additive manufacturing of all or part of a three-dimensional object (106, 6, 6') on a manufacturing support (104, 4, 4'), characterized in that it comprises: - at least one material deposit ramp (20, 30, 30a, 30b) by addition intended to be arranged above the manufacturing support (104, 4, 4'), extending along a longitudinal axis (X) and comprising a plurality of material deposit nozzles (21 to 24; 31 to 38) each provided with at least one distribution orifice (26), - each of the material depositing nozzles (21 to 24; 31 to 38) comprising a closure means (28a) movable between a closure position and a plurality of opening positions of said dispensing orifice (26), and an actuator (28b) for controlling the movement of the closure means (28a) between the closure and opening positions, - the closing means (28a) being controllable independently of one another, and in that - the device (10) further comprises at least: - an actuation system configured to generate a relative translational movement of the material depositing ramp (20, 30, 30a, 30b) relative to the manufacturing support (104, 4, 4') in at least one vertical direction (Z) and / or one longitudinal direction (X), and - a drive member (15) of the manufacturing support capable of driving the manufacturing support (104, 4, 4') in a direction of advancement (Y) perpendicular to the longitudinal direction (X), characterized in that the material depositing nozzles (31 to 38) of the material depositing ramp (30, 30a, 30b) are arranged in the same plane comprising a longitudinal axis (X) perpendicular to the direction of advancement (Y), said nozzles (31 to 38) being vertically offset relative to each other.

2. Device (10) according to claim 1, comprising at least one extruder (18) connected to the material depositing ramp (20, 30, 30a, 30b) and supplying said ramp (20, 30, 30a, 30b) with a rod of molten material.

3. Device (10) according to claim 2, in which the extruder (18) is central and associated with all of the material depositing nozzles.

4. Device (10) according to claim 2, comprising a plurality of extruders, each associated with at least two material depositing nozzles.

5. Device (10) according to any one of claims 2 to 4, in which each material depositing nozzle (21 to 24; 31 to 38) comprises a chamber (25) for receiving the molten material coming from the extruder (18) in communication with the distribution orifice (26).

6. Device (10) according to any one of the preceding claims, in which the distribution orifice (26) of each of the material depositing nozzles (21 to 24; 31 to 38) has a rectangular or circular section.

7. Device (10) according to any one of the preceding claims, wherein each of the sealing means (28a) comprises a needle.

8. Device (10) according to any one of the preceding claims, in which the material depositing nozzles (21, 22, 23, 24) are arranged on the material depositing ramp (20) in a single row (RI, R2, R3, R4) in the longitudinal direction (X).

9. Device (10) according to any one of claims 1 to 7, in which the material depositing nozzles (21, 22, 23, 24) are arranged on the material depositing ramp (20) in at least two rows (RI, R2, R3, R4) parallel and offset along a transverse axis (Y) perpendicular to the longitudinal direction (X) and perpendicular to the vertical direction (Z), each row (RI, R2, R3, R4) comprising at least two material depositing nozzles aligned along the longitudinal direction (X).

10. Device (10) according to any one of the preceding claims, comprising two material depositing ramps (30a, 30b) each associated with its own actuation system, said ramps being movable in translation in the longitudinal direction (X) in two opposite directions. 1 1. Device (10) according to any one of the preceding claims, in which the actuation system is configured to move the material depositing ramp (20, 30, 30a, 30b) in translation relative to the manufacturing support (104, 4, 4') in a vertical direction (Z) and / or the longitudinal direction (X).

12. Method for additive manufacturing of all or part of a three-dimensional object (106, 6, 6') on a manufacturing support (104, 4, 4') by a manufacturing device comprising at least one material deposit ramp (20, 30, 30a, 30b) arranged above the manufacturing support (104, 4, 4'), extending along a longitudinal axis (X) and comprising a plurality of material deposit nozzles (21 to 24; 31 to 38) by addition each provided with at least one distribution orifice (26), the material deposit nozzles (31 to 38) of the material deposit ramp (30, 30a, 30b) being arranged in the same plane comprising a longitudinal axis (X) perpendicular to the direction of advance (Y), said nozzles (31 to 38) being vertically offset relative to each other in which: - each of the material depositing nozzles (21 to 24; 31 to 38) deposits extruded material onto the manufacturing support (104, 4, 4') during a material depositing sequence, - closing means (28a) each associated with one of the material depositing nozzles (21 to 24; 31 to 38) are controlled independently of each other to be moved between a closing position and a plurality of opening positions of the dispensing orifice (26) of each nozzle according to the geometry of the three-dimensional object (106, 6, 6') to be manufactured, during each material depositing sequence, the manufacturing support (104) is moved in translation relative to the material depositing ramp (20, 30, 30a, 30b) along the transverse axis (Y) between an initial position and a final position; and - after each material depositing sequence, the material depositing ramp (20, 30, 30a, 30b) and the manufacturing support have a relative movement with respect to each other in translation in at least one vertical direction (Z) and / or one longitudinal direction (X), characterized in that the width of the material depositing ramp (20) is less than the width of the three-dimensional object (106, 6, 6') to be manufactured, and in that during each material depositing sequence, each material depositing nozzle (21 to 24) deposits material over a thickness along a given material line, wherein said material depositing ramp (20) is moved in translation relative to the manufacturing support (104, 4, 4') axially along the longitudinal axis (X) by the width of said ramp (20) after each material depositing sequence,and in which these operations are repeated until obtaining the first layer of material (Cj) comprising all the lines of material (Li)., 13. The method of claim 12, wherein: - during each material deposit sequence, each material deposit nozzle material (21 to 24) deposits material along a thickness of at least one given material line (Li), and the set of material depositing nozzles (21 to 24) deposits material along a first layer corresponding to the width of the three-dimensional object to be manufactured, and in which - after each material depositing sequence, the material depositing ramp (20) is moved in translation relative to the manufacturing support (104, 4, 4') along the vertical axis (Z) and each of the material depositing nozzles (21 to 24) deposits material along the same given material line (Li), to form a second layer superimposed on the first layer, and in which these operations are repeated until the desired thickness of the three-dimensional object (106, 6, 6') is obtained.

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