JP6356177B2 - Additive manufacturing equipment - Google Patents

Description

  The present invention relates to an additive manufacturing apparatus.

  In the powder sintering lamination method using laser light, material powder is uniformly distributed on a modeling table to form a material powder layer, and a predetermined portion of the material powder layer is irradiated with laser light and sintered. A sintered layer is formed by the above, a material powder is uniformly distributed on the sintered layer, a new material powder layer is formed, and the new material powder layer is irradiated with laser light and sintered. By forming a new sintered layer joined to the lower sintered layer, and repeating these, a desired three-dimensional structure made of a sintered body in which a plurality of sintered layers are laminated and integrated Form.

  When sintering the material powder with laser light, the material powder is protected from being altered and the surroundings of the predetermined modeling area are placed in order to stably irradiate the laser light with the required energy. It is required to keep oxygen free as much as possible. Therefore, the current additive manufacturing apparatus has a configuration in which the material powder is distributed in a chamber filled with an inert gas (for example, nitrogen gas) that does not substantially react with the material powder and the laser beam is irradiated. It is common.

  In addition, when the material powder is irradiated with laser light and sintered, specific smoke called fume is generated. When the fume fills the chamber, the laser beam is shielded and the laser beam with the required energy does not reach the sintering site. As a result, the abnormally sintered portion (fired) is added to the layered object formed as shown in FIG. Protrusions formed by spattering on the surface of the layered layer) and voids (cavities inside the modeled object) are easily formed, and the quality of the layered modeled object is deteriorated. Alternatively, the abnormally sintered portion may collide with a blade for leveling the material powder when the material powder layer is formed. At this time, since it is necessary to remove the abnormally sintered portion by cutting, for example, extra time is required. Therefore, it is configured to supply clean inert gas while constantly discharging the dirty inert gas containing a large amount of fumes in the chamber so that the fumes do not shield the laser beam.

  Fume is generated from the sintered part and rises so as to cover the vicinity of the sintered part, but the laser light is basically irradiated from the upper side in the vertical direction with respect to the sintered part. Irradiation paths overlap. Therefore, it may not be possible to sufficiently remove the fumes simply by circulating the inert gas in the chamber. Therefore, it is necessary to discharge the inert gas in the chamber so as to guide the fumes away from the irradiation path.

  For example, in Patent Document 1, a cover that surrounds a window coaxially with laser light is provided, and an inert gas having a temperature or specific gravity different from that of the atmosphere in the chamber is supplied into the cover, thereby convection of the atmosphere in the chamber. A modeling apparatus is disclosed. Patent Document 2 and Patent Document 3 disclose a layered manufacturing apparatus in which a cover (a cover frame and a shroud) moves in accordance with the movement of a laser beam.

Japanese Patent No. 57674751 Japanese Patent No. 5355213 JP 2014-125463 A

  However, like the additive manufacturing apparatus disclosed in Patent Document 1, supplying inert gases having different temperatures or specific gravity has a problem that it is difficult to maintain the atmosphere in the chamber. In addition, the additive manufacturing apparatus disclosed in Patent Document 2 and Patent Document 3 is easier to maintain the atmosphere in the chamber than the additive manufacturing apparatus disclosed in Patent Document 1, but the supply of inert gas Since the suction of the fumes is performed in the same space in the cover, the fumes are likely to stay in the cover, and the atmosphere in the cover may be deteriorated. It is necessary to remove the fumes from the laser light irradiation path more quickly and effectively.

  This invention is made | formed in view of such a situation, and provides the layered modeling apparatus which can model a desired molded article with high quality.

  According to the present invention, a chamber that covers the modeling region and is filled with an inert gas, and a laser light source that generates a laser beam that forms a sintered layer by sintering the material powder distributed in the modeling region. A cover unit that is formed from the upper part in the chamber toward the modeling region and that opens to the modeling region side; a holder in which the cover unit is provided; and at least the position of the holder or the direction of the cover unit A driving device that controls either one of them, and the cover unit is configured to form the inert gas supply cover that discharges the supplied inert gas from a discharge port to the modeling region, and the modeling layer is formed when the sintered layer is formed. A fume suction cover for sucking an inert gas containing fumes generated on the region from a suction port, and the driving device is configured such that the laser beam is emitted from the inert gas. A layered structure configured to control at least one of the position of the holder and the direction of the cover unit in accordance with the irradiation path of the laser beam so as to pass through the inside of the feed cover and irradiate the modeling region. A modeling apparatus is provided.

  The additive manufacturing apparatus according to the present invention includes a cover unit having an inert gas supply cover and a fume suction cover, and is configured such that a laser beam irradiation path is provided inside a clean inert gas supply cover. Thereby, since interruption | blocking of the laser beam by a fume is suppressed and the produced | generated fume is attracted | sucked efficiently via a suction cover, a higher quality molded article can be obtained.

  Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.

  Preferably, the discharge port of the inert gas supply cover is provided on the modeling direction side of the cover unit, and the suction port of the fume suction cover is provided on the anti-modeling direction side of the cover unit.

  Preferably, in the cover unit, the discharge port and the suction port are provided adjacent to each other.

  Preferably, in the cover unit, the inert gas supply cover and the fume suction cover are integrally provided.

  Preferably, the irradiation end of the laser light source is provided inside the holder, and the driving device moves the position of the holder to move the irradiation position of the laser light.

  Preferably, the irradiation position of the laser beam can be controlled by an optical deflector, and the driving device is configured to control the orientation of the cover unit in accordance with the irradiation path of the laser beam.

  Preferably, the inert gas supply cover is formed so that a cross-sectional area decreases from an upper part in the chamber toward the modeling region.

  Preferably, the diameter of the discharge port in the inert gas supply cover is a length of a substantial sintering range of the laser beam orthogonal to the modeling direction in one scanning of the laser beam related to formation of the sintered layer. 2 to 20 times the height.

It is the schematic which concerns on a prior art and shows the fall of the quality of the layered product by a fume. 1 is a configuration diagram of an additive manufacturing apparatus according to a first embodiment of the present invention. It is a perspective view of the powder layer forming apparatus 3 which concerns on 1st and 2nd embodiment of this invention. It is a perspective view of the recoater head 11 concerning the 1st and 2nd embodiment of the present invention. It is the perspective view seen from another angle of the recoater head 11 concerning the 1st and 2nd embodiments of the present invention. It is the schematic which shows the cross section of the cover unit 70 which concerns on 1st Embodiment of this invention. It is the schematic which illustrates the irradiation area | region of a laser beam L, and a division area. 3 is a schematic view illustrating an irradiation path of laser light L. FIG. It is explanatory drawing of the additive manufacturing method using the additive manufacturing apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing of the additive manufacturing method using the additive manufacturing apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing of the additive manufacturing method using the additive manufacturing apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing of the additive manufacturing method using the additive manufacturing apparatus which concerns on 1st Embodiment of this invention. It is a block diagram of the additive manufacturing apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram of the additive manufacturing apparatus which concerns on the modification of 1st Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Various characteristic items shown in the following embodiments can be combined with each other.

1. First Embodiment First, an additive manufacturing apparatus according to a first embodiment of the present invention will be described. As shown in FIG. 2, the additive manufacturing apparatus according to the first embodiment of the present invention includes a powder layer forming apparatus 3 in a chamber 1 filled with an inert gas.

  The powder layer forming apparatus 3 includes a base table 4 having a modeling region R, and a recoater head 11 that is arranged on the base table 4 and configured to be movable in the horizontal uniaxial direction (arrow B direction). . The modeling region R is provided with a modeling table 5 that can move in the vertical direction (the direction of arrow A in FIG. 2). When the additive manufacturing apparatus is used, the modeling plate 7 is disposed on the modeling table 5, and the material powder layer 8 is formed thereon. In addition, the predetermined irradiation region exists in the modeling region R and approximately matches the region surrounded by the contour shape of the desired three-dimensional structure.

  A powder holding wall 26 is provided around the modeling table 5. In the powder holding space surrounded by the powder holding wall 26 and the modeling table 5, unsintered material powder is held. Although not shown in FIG. 2, a powder discharge unit capable of discharging the material powder in the powder holding space may be provided below the powder holding wall 26. In such a case, the unsintered material powder is discharged from the powder discharge section by lowering the modeling table 5 after the completion of the layered modeling. The discharged material powder is guided to the shooter by the shooter guide and is accommodated in the bucket through the shooter.

  As shown in FIGS. 3 to 5, the recoater head 11 includes a material storage portion 11 a, a material supply portion 11 b, and a material discharge portion 11 c.

  The material accommodating part 11a accommodates material powder. The material powder is, for example, metal powder (eg, iron powder), for example, a spherical shape having an average particle diameter of 20 μm. The material supply unit 11b is provided on the upper surface of the material storage unit 11a, and serves as a receiving port for the material powder supplied from the material supply device (not shown) to the material storage unit 11a. The material discharge part 11c is provided in the bottom face of the material storage part 11a, and discharges the material powder in the material storage part 11a. In addition, the material discharge | emission part 11c is a slit shape extended in the horizontal uniaxial direction (arrow C direction) orthogonal to the moving direction (arrow B direction) of the recoater head 11. FIG.

  Also, blades 11fb and 11rb, a recoater head supply port 11fs, and a recoater head discharge port 11rs are provided on both side surfaces of the recoater head 11. The blades 11fb and 11rb flatten the material powder discharged from the material discharge portion 11c to form the material powder layer 8. The recoater head supply port 11fs and the recoater head discharge port 11rs are respectively provided along a horizontal one-axis direction (arrow C direction) orthogonal to the moving direction of the recoater head 11 (arrow B direction). Supply and discharge (details will be described later). In this specification, the “inert gas” is a gas that does not substantially react with the material powder, and examples thereof include nitrogen gas, argon gas, and helium gas.

  A laser light source 42 is provided above the chamber 1. As shown in FIGS. 2 and 6, the laser light source 42 is connected to the holder 43 through the optical cable 43a and the optical connector 43a. Since the laser beam L is irradiated from the tip of the optical connector 43a, the tip of the optical connector 43a is represented as a laser beam irradiation end 43b in FIG.

  In the holder 43, the material powder layer 8 in which the laser light L passes through the collimator 44, the optical processing unit 45, the protective glass 45 a, and the inert gas supply cover 71 in the cover unit 70 and is distributed on the modeling region R. Is configured to extend from the upper part in the chamber 1 toward the modeling region R. The holder 43 can be moved to an arbitrary position on the modeling region R by the driving device 65. The collimator 44 makes the laser light L parallel light. The optical processing unit 45 controls the shape and the like of the irradiation spot of the laser light L. The cover unit 70 will be described in detail later.

  According to the configuration as described above, the laser beam L is irradiated in the direction directly below the holder 43. Therefore, the laser beam L can be irradiated to a desired position by moving the holder 43 to a desired position.

The type of the laser beam L is not limited as long as the material powder can be sintered, and examples thereof include a CO ₂ laser, a fiber laser, and a YAG laser.

  A cover unit 70 is provided below the holder 43. By controlling the height of the holder 43, the tip of the cover unit 70 is configured to be close to the modeling region R, and the tip is open. The cover unit 70 has two covers including an inert gas supply cover 71 and a fume suction cover 72, and their openings (referred to as discharge ports 71b and suction ports 72b, respectively) are substantially adjacent to each other. The In the example shown in FIG. 6, an inert gas supply cover 71 and a fume suction cover 72 are integrally formed.

  The inert gas supply cover 71 has a cover unit supply port 71a as a supply port for supplying an inert gas therein. The cover unit supply port 71a is connected to an inert gas supply device 15 to be described later, and is configured so that clean inert gas flows into the inert gas supply cover 71 through the pores 71c. The inside of the inert gas supply cover 71 is spatially separated via the optical processing unit 45 and the protective glass 45a, and the protective glass 45a allows the inert gas containing fumes while transmitting the laser light L. Prevent inflow to the top. For example, when the laser beam L is a fiber laser or a YAG laser, the protective glass 45a can be made of quartz glass.

  The fume suction cover 72 is provided so that the suction port 72 b is substantially adjacent to the discharge port 71 b in the inert gas supply cover 71. Further, the fume suction cover 72 is provided so that its inside faces the side surface of the holder 43, and a cover unit discharge port 72a is provided on the side surface. The cover unit discharge port 72 a is connected to a fume collector 19, which will be described later, via the duct box 21, and is configured such that an inert gas containing fume flows into the fume suction cover 72.

  Next, the inert gas supply / discharge system will be described. The inert gas supply / discharge system includes a plurality of inert gas supply ports and discharge ports provided in the chamber 1, and pipes that connect the supply ports and the discharge ports to the inert gas supply device 15 and the fume collector 19. Including. In the present embodiment, a supply port including a recoater head supply port 11fs, a chamber supply port 1b, a sub supply port 1e, and a cover unit supply port 71a, a chamber discharge port 1c, a recoater head discharge port 11rs, and a cover unit discharge port. A discharge port including an outlet 72a is provided.

  The recoater head supply port 11fs is provided so as to face the chamber discharge port 1c corresponding to the installation position of the chamber discharge port 1c. Preferably, the recoater head supply port 11fs faces the chamber discharge port 1c when the recoater head 11 is located on the opposite side of a predetermined irradiation region with respect to the installation position of the material supply device (not shown). As shown, the recoater head 11 is provided on one surface along the arrow C direction.

  The chamber discharge port 1c is provided on the side plate of the chamber 1 at a predetermined distance from a predetermined irradiation region so as to face the recoater head supply port 11fs. A suction device (not shown) may be provided so as to be connected to the chamber outlet 1c. The suction device helps to efficiently remove fumes from the irradiation path of the laser light L. Further, a larger amount of fumes can be discharged from the chamber discharge port 1c by the suction device, and the fumes are less likely to diffuse into the modeling space 1d.

  The chamber supply port 1b is provided on the end of the base table 4 so as to face the chamber discharge port 1c with a predetermined irradiation region in between. When the recoater head 11 passes through a predetermined irradiation region and the recoater head supply port 11fs faces the chamber discharge port 1c without interposing the predetermined irradiation region, the chamber supply port 1b is The head supply port 11fs is selectively switched to the chamber supply port 1b to be opened. For this reason, the chamber supply port 1b supplies the inert gas having the same predetermined pressure and flow rate as the inert gas supplied from the recoater head supply port 11fs toward the chamber discharge port 1c, so that it is always inert in the same direction. It is advantageous in that a gas flow can be created and stable sintering can be performed.

  The recoater head discharge port 11rs is provided along the arrow C direction on the side surface opposite to the one surface of the recoater head 11 where the recoater head supply port 11fs is provided. When the inert gas cannot be supplied from the recoater head supply port 11fs, in other words, when the inert gas is supplied from the chamber supply port 1b, some flow of the inert gas is created near the predetermined irradiation region. Therefore, the fumes can be more efficiently excluded from the irradiation path of the laser light L.

  In addition, the inert gas supply / discharge system of the present embodiment forms a clean inert gas that is provided on the side plate of the chamber 1 so as to face the chamber discharge port 1c and from which the fumes fed from the fume collector 19 are removed. The sub supply port 1e that supplies the space 1d, the cover unit supply port 71a that supplies inert gas to the inside of the inert gas supply cover 71 in the cover unit 70, and the inert material that contains a large amount of fume via the fume suction cover 72. And a cover unit discharge port 72a for discharging gas.

  An inert gas supply device 15 and a fume collector 19 are connected to the inert gas supply system to the chamber 1. The inert gas supply device 15 has a function of supplying an inert gas, and includes, for example, a membrane nitrogen separator that extracts nitrogen gas from ambient air. In the present embodiment, as shown in FIG. 2, the recoater head supply port 11fs, the chamber supply port 1b, and the cover unit supply port 71a are connected.

  The fume collector 19 has duct boxes 21 and 23 on the upstream side and the downstream side, respectively. The inert gas containing the fumes discharged from the chamber 1 is sent to the fume collector 19 through the duct box 21, and the clean inert gas from which the fumes have been removed in the fume collector 19 is passed through the duct box 23 to the auxiliary supply port of the chamber 1. 1e. With such a configuration, the inert gas can be reused.

  As a fume discharge system, as shown in FIG. 2, the chamber discharge port 1 c, the recoater head discharge port 11 rs, the cover unit discharge port 72 a and the fume collector 19 are connected through the duct box 21. The clean inert gas after the fume is removed in the fume collector 19 is returned to the chamber 1 and reused.

  The inert gas supply / exhaust system is merely an example and is not limited thereto. In particular, the inert gas supply system is a cover unit supply provided in the inert gas supply cover 71 in the cover unit 70 provided in the holder 43. The fume discharge system is connected to a cover unit discharge port 72 a included in the inert gas supply cover 71 in the cover unit 70 provided in the holder 43.

  As shown in FIG. 6, by supplying an inert gas to the cover unit supply port 71a, the inert gas passes through the inert gas supply cover 71 from the discharge port 71b toward the modeling space 1d (particularly the modeling region R). Discharged. As a result, the inside of the inert gas supply cover 71 can be kept clean with no fume. As a result, the laser beam L passing through the inside of the inert gas supply cover 71 is irradiated to the material powder layer 8 without being blocked by fume.

  Preferably, the inert gas supplied to the cover unit supply port 71a may be set to a pressure slightly higher (for example, 5% or higher) than the pressure of the inert gas supplied to the other supply ports. Thereby, the airflow which goes to the modeling space 1d from the inside of the inert gas supply cover 71 becomes easy to be formed. Further, in order to keep the inside of the inert gas supply cover 71 particularly clean, it is preferable to increase the flow rate of the air flow toward the discharge port 71b so as not to wind up the material powder. Moreover, it is preferable that the inert gas is locally supplied to the irradiation position of the laser beam L. Therefore, it is preferable that the cross section of the inert gas supply cover 71 has a structure in which the cross section decreases from the upper part toward the lower part. Note that the cross-sectional shapes and configurations of the holder 43 and the cover unit 70 shown in FIG. 6 are merely examples and are not limited thereto.

  In this embodiment, the inert gas from the fume collector 19 is sent to the sub supply port 1e, and the inert gas from the inert gas supply device 15 is supplied to the recoater head supply port 11fs, the chamber supply port 1b, and the cover unit. It is configured to be sent to the mouth 71a. Although there is a possibility that fumes that could not be removed remain in the inert gas from the fume collector 19, in the configuration of the present embodiment, the space in which the inert gas from the fume collector 19 requires particularly high purity is required. Since it is not supplied to the inside of the inert gas supply cover 71 and the space near the modeling region R, the influence of residual fume can be minimized. Also, the inert gas supply pressure from the fume collector 19 is increased by making the supply pressure of the inert gas from the inert gas supply device 15 higher than the supply pressure of the inert gas from the fume collector 19. It is suppressed that the inside of 71 and the space of the modeling area | region R vicinity are approached, and the influence of a residual fume is suppressed more effectively.

  As described above, there is an irradiation path of the laser beam L inside the inert gas supply cover 71, and the material powder layer 8 is sintered by the irradiation of the laser beam L to form a sintered layer 8 f. At this time, fumes are generated. In the present embodiment, the discharge port 71 b in the inert gas supply cover 71 and the suction port 72 b of the fume suction cover 72 are substantially adjacent to each other, and the holder 43 is lowered by the driving device 65 to change the suction port 72 b of the fume suction cover 72. The modeling region R can be made as close as possible. Thus, the configuration is such that the fumes generated by the irradiation of the laser beam L can be sucked at a position that is clearly close to the position where the fumes are generated, as compared with the conventional technology.

  Further, as shown in FIG. 6, the discharge port 71 b of the inert gas supply cover 71 is provided on the modeling direction side of the cover unit 70, and the suction port 72 b of the fume suction cover 72 is on the counter modeling direction side of the cover unit 70. It is preferable to be provided. With such a configuration, since an air flow is formed in the direction opposite to the modeling direction, an air flow of an inert gas that collects fumes discharged and generated from the discharge port 71b and transports it to the suction port 72b can be more effectively formed. Furthermore, since the suction port 72b is positioned on the sintered layer that has already been irradiated with the laser beam L during modeling, material powder is prevented from being inadvertently sucked from the suction port 72b. Can do. In order to make such a configuration, when the orientation of the cover unit 70 is fixed, the modeling direction may be made constant. Alternatively, the cover unit 70 may be configured to be rotatable, and the positions of the discharge port 71b and the suction port 72b may be changed according to the modeling direction.

  Here, the modeling direction will be described. In the formation of the sintered layer by the laser beam L, as shown in FIG. 7A, the irradiation region for each material powder layer 8 is divided into predetermined lengths, and each divided region is divided. The laser beam L is raster-scanned to form a sintered layer, and a desired sintered layer corresponding to the irradiated region is formed. Here, the width in which the sintered layer is divided into each divided region is referred to as a divided width, and the direction in which the sintered layer is gradually formed in each divided region is referred to as a forming direction. In addition, the arrow in Fig.7 (a) has shown an example of the irradiation path | route of the laser beam L in a certain division area, and it demonstrates in detail below.

  FIG. 8 illustrates the irradiation path of the laser light L for each divided region. FIG. 8A is an example using a laser beam L having a spot shape having a horizontally long shape (in this example, a rounded rectangular shape) whose longitudinal direction matches the length of the division width. It matches the direction. FIG. 8B and FIG. 8C are examples using the laser beam L having a substantially circular spot shape, and linear scanning paths having the same length as the divided width are arranged in parallel, and in the modeling direction. Each linear scan is continuously performed along the line. In such a case, the modeling direction and each linear scanning direction are orthogonal to each other. In the irradiation path of the laser beam L indicated by the arrow in FIG. 8, the solid line portion indicates that the irradiation of the laser beam L is ON, and the dotted line portion indicates that the irradiation of the laser beam L is OFF. Show.

  Each linear scanning in the layered manufacturing method using the laser beam L having a substantially circular spot shape as shown in FIG. 8B or FIG. 8C is as fast as possible in order to shorten the modeling time. In general, an optical deflector capable of high-speed scanning such as a galvano scanner is used as a scanning device for the laser light L.

  On the other hand, in this embodiment, since the irradiation position of the laser beam L is scanned by the driving device 65, high-speed scanning cannot be performed as compared with scanning by a conventional galvano scanner or the like. Therefore, it is preferable to use a laser beam L having a horizontally elongated spot shape whose longitudinal direction matches the length of the division width as shown in FIG. On the other hand, when the laser beam L having a substantially circular spot shape as shown in FIGS. 8B and 8C is used, it is suitable to use an optical deflector capable of high-speed scanning such as a galvano scanner. This will be described in the second embodiment. Alternatively, such a light deflector may be provided inside the holder 43, and the combination of both may be performed, such as scanning by the driving device 65 for the modeling direction and scanning by the optical deflector for the direction related to the divided width. .

  In forming the sintered layer, each divided region may be further divided along the forming direction. Here, as an example, as shown in FIG. 7B, a certain divided region is divided into a divided region α, a divided region β, and a divided region γ. At this time, the sintering of the divided regions further divided is performed in the order of the divided region α, the divided region γ, and the divided region β, for example. Good. Moreover, you may form a sintered layer by the vector scan in the peripheral part of an irradiation area | region. Note that, when performing vector scanning, the modeling direction is exceptionally defined as the same direction as the scanning direction.

  The diameter of the discharge port 71b is preferably about 2 to 20 times the length of the divided width. In other words, it is about 2 to 20 times the length of the substantial sintering range of the laser beam L perpendicular to the modeling direction in one scanning of the laser beam L related to the formation of the sintered layer. Is preferred. According to such a configuration, interference between the inert gas supply cover 71 and the laser beam L can be prevented, and the inert gas can be supplied more locally.

  Next, the additive manufacturing method using the additive manufacturing apparatus will be described with reference to FIGS. 2 and 9 to 12. 9 to 12, some of the illustrated components are omitted in FIG. 2 in consideration of visibility.

  First, the height of the modeling table 5 is adjusted to an appropriate position with the modeling plate 7 placed on the modeling table 5 (FIG. 9). In this state, the first layer on the modeling plate 7 is moved by moving the recoater head 11 filled with the material powder in the material container 11a from the left side to the right side of the modeling region R in the direction of arrow B in FIG. The material powder layer 8 is formed (FIG. 10). As shown in FIGS. 9 and 10, when the recoater head 11 is moved, the holder 43 is moved to the retracted position (upper right in the figure) in order to prevent physical interference between the recoater head 11 and the holder 43. Evacuated.

  Subsequently, as shown in FIG. 11, the holder 43 is moved from the retracted position to the irradiation position, and a predetermined portion in the material powder layer 8 is irradiated with the laser light L, so that the laser light irradiation portion of the material powder layer 8 is changed. By sintering, a first sintered layer 81f is obtained. The fumes generated during the sintering are mainly sucked from the suction port 72b of the fume suction cover 72 and discharged through the cover unit discharge port 72a.

  Subsequently, the height of the modeling table 5 is lowered by one layer of the material powder layer 8, and the recoater head 11 is moved from the right side to the left side of the modeling region R, whereby the second layer material is formed on the sintered layer 81f. A powder layer 8 is formed. While the recoater head 11 is moving, fumes are sucked by the recoater head discharge port 11rs. Fume suction at this time is particularly effective because it is performed at a position very close to the fume generation site.

  Subsequently, a predetermined portion in the material powder layer 8 is irradiated with the laser light L to sinter the laser light irradiated portion of the material powder layer 8, so that the second sintered layer as shown in FIG. 82f is obtained. The fumes generated during the sintering are mainly sucked from the suction port 72b of the fume suction cover 72 and discharged through the cover unit discharge port 72a.

  By repeating the above steps, the third and subsequent sintered layers are formed. Adjacent sintered layers are firmly fixed to each other.

  After forming the required number of sintered layers, the shaped sintered body can be obtained by removing the unsintered material powder. This sintered body can be used, for example, as a mold for resin molding.

2. Second Embodiment Hereinafter, an additive manufacturing apparatus according to a second embodiment of the present invention will be described. In addition, detailed description is abbreviate | omitted about the part which is common in the additive manufacturing apparatus which concerns on 1st Embodiment.

In the second embodiment, as shown in FIG. 13, a laser including a laser light source 42 that generates laser light L and an optical deflector that enables laser light L to be two-dimensionally scanned in the modeling region R above the chamber 1. The light irradiation unit 13 is provided, and the laser light L output from the laser light irradiation unit 13 passes through the window 1a provided in the chamber 1 and is applied to the material powder layer 8 formed in the modeling region R. . The laser beam irradiation unit 13 only needs to be configured to be capable of two-dimensional scanning with the laser beam L in the modeling region R. For example, a pair of galvano scanners is used as an optical deflector. Alternatively, instead of a pair of galvano scanners, a KTN scanner whose refractive index can be freely controlled by applying a voltage may be used. Note here the KTN scanner, _KTN having an electro-optic effect _{(KTa 1-x Nb x O} 3) crystal or _{KLTN (K 1-y Li y} Ta 1-x Nb x O 3) optical deflector using the crystal Say. The type of the laser beam L is not limited as long as the material powder can be sintered, and examples thereof include a CO ₂ laser, a fiber laser, and a YAG laser. The window 1a is formed of a material that can transmit the laser light L. For example, when the laser beam L is a fiber laser or a YAG laser, the window 1a can be made of quartz glass.

  A fume diffusion portion 17 is provided on the upper surface of the chamber 1 so as to cover the window 1a. The fume diffusing unit 17 includes a cylindrical casing 17a and a cylindrical diffusing member 17c disposed in the casing 17a. An inert gas supply space 17d is provided between the housing 17a and the diffusion member 17c. An opening 17b is provided on the bottom surface of the housing 17a inside the diffusion member 17c. The diffusing member 17c is provided with a large number of pores 17e, and the clean inert gas supplied from the fume diffusing device supply port 17g to the inert gas supply space 17d fills the clean space 17f through the pores 17e. . And the clean inert gas with which the clean space 17f was filled is ejected toward the downward direction of the fume spreading | diffusion part 17 through the opening part 17b. Note that the opening 17b is preferably formed to have as small a cross-sectional area as possible in order to suppress the intrusion of the fumes into the clean space 17f as much as possible. Specifically, the laser light is spread over the entire modeling region R. It is preferable that the laser beam L be formed in a minimum cross-sectional area that is not blocked by the housing 17a when L is two-dimensionally scanned.

  The fume diffusing unit 17 is connected to the cover unit 70. The cover unit 70 according to the second embodiment also has an inert gas supply cover 71 and a fume suction cover 72 as in the first embodiment. The cover unit 70 according to the second embodiment is provided in the holder 43, and its direction is controlled by the driving device 65 in accordance with the irradiation path of the laser light L. It should be noted that the position at which the laser beam L enters the cover unit 70 is shifted as the angle of the galvano scanner is changed only by controlling the direction. Therefore, the laser beam L is carried out so as to pass through the cover unit 70 and reach the modeling region R regardless of the deviation.

  Alternatively, not only the direction of the cover unit 70 but also the position of the holder 43 in the horizontal direction may be moved in accordance with the irradiation path of the laser light L so that the above-described deviation does not occur. In other words, the optical axis of the laser beam L may be substantially aligned with the central axis of the inert gas supply cover 71 in the cover unit 70 so that the deviation does not occur.

  The clean inert gas filled in the clean space 17f passes through the inside of the inert gas supply cover 71 from the opening 17b and is discharged from the discharge port 71b toward the modeling space 1d (particularly the modeling region R). At this time, if the cross section of the inert gas supply cover 71 has a cross-sectional area that decreases from the top to the bottom, the flow rate of the discharged inert gas is improved, and the inside of the inert gas supply cover 71 is more preferably It can be kept clean with no fume. As a result, the laser beam L passing through the inside of the inert gas supply cover 71 is irradiated to the material powder layer 8 without being blocked by fume. Further, the inert gas can be supplied more locally.

  The discharge port 71 b in the inert gas supply cover 71 and the suction port 72 b of the fume suction cover 72 are substantially adjacent to each other, and the suction port 72 b of the fume suction cover 72 can be brought as close as possible to the modeling region R by the driving device 65. As a result, the fumes generated by the irradiation of the laser beam L can be sucked at a position that is clearly close to that of the prior art.

  Further, similarly to the first embodiment, the discharge port 71 b of the inert gas supply cover 71 is provided on the modeling direction side of the cover unit 70, and the suction port 72 b of the fume suction cover 72 is the counter-modeling direction of the cover unit 70. It is preferable to be provided on the side. With such a configuration, since an air flow is formed in the direction opposite to the modeling direction, an air flow of an inert gas that collects fumes discharged and generated from the discharge port 71b and transports it to the suction port 72b can be more effectively formed. Furthermore, since the suction port 72b is positioned on the sintered layer that has already been irradiated with the laser beam L during modeling, material powder is prevented from being inadvertently sucked from the suction port 72b. Can do. In order to make such a configuration, when the cover unit 70 is fixed, the modeling direction may be made constant. Alternatively, the cover unit 70 may be configured to be rotatable, and the positions of the discharge port 71b and the suction port 72b may be changed according to the modeling direction.

3. Modified Example As described above, the additive manufacturing apparatus according to the first and second embodiments includes the cover unit 70 in which the inert gas supply cover 71 and the fume suction cover 72 are integrally configured. However, the present invention is not limited to this example, and for example, the inert gas supply cover 71 and the fume suction cover 72 may be independently arranged. Alternatively, although the discharge port 71b and the suction port 72b are adjacent to each other, the inert gas supply cover 71 and the fume suction cover 72 may not be integrated. The cross-sectional shape shown in FIG. 14 is merely an example and is not limited to this. In FIG. 14, the first embodiment is taken as an example and a modification is shown, but the same applies to the second embodiment.

  As described above, both of the additive manufacturing apparatuses according to the first and second embodiments improve the flow rate of the inert gas by the structure in which the cross section of the inert gas supply cover 71 becomes smaller from the upper part toward the lower part. Thus, the inside of the inert gas supply cover 71 can be kept clean with no fume. Further, the inert gas can be supplied more locally. However, the present invention is not limited to this example, and any structure may be used as long as an air flow that is fast enough to prevent the material powder from being wound up and an inert gas can be supplied locally. For example, it may have a pipe shape and a small cross section as a whole.

  The additive manufacturing apparatus according to the first and second embodiments may include a machining head having a spindle to which a cutting tool can be attached. In this case, it is possible to cut the shaped article every time a predetermined number (for example, 10 layers) of sintered layers is formed.

1: chamber, 1a: window, 1b: chamber supply port, 1c: chamber discharge port, 1d: modeling space, 1e: auxiliary supply port, 3: powder layer forming device, 4: base table, 5: modeling table, 7 : Modeling plate, 8: material powder layer, 8f, 81f, 82f: sintered layer, 11: recoater head, 11a: material container, 11b: material supply unit, 11c: material discharge unit, 11fb, 11rb: blade 11 fs: recoater head supply port, 11 rs: recoater head discharge port, 13: laser light irradiation unit, 15: inert gas supply device, 17: fume diffusion unit, 17a: housing, 17b: opening, 17c: Diffusion member, 17d: inert gas supply space, 17e: pore, 17f: clean space, 17g: fume diffusion device supply port, 19: fume collector, 21, 23: duct box, 26 Powder holding wall, 42: laser light source, 42a: optical cable, 43: holder, 43a: optical connector, 43b: laser light irradiation end, 44: collimator, 45: optical processing unit, 45a: protective glass, 65: driving device, 70: Cover unit, 71: Inert gas supply cover, 71a: Cover unit supply port, 71b: Discharge port, 71c: Fine hole, 72: Fume suction cover, 72a: Cover unit discharge port, 72b: Suction port, L: Laser light, R: modeling area.

Claims (7)

A chamber covering the modeling area and filled with an inert gas;
A laser light source for generating a laser beam that sinters the material powder distributed in the modeling region to form a sintered layer;
A cover unit that is formed from the upper part in the chamber toward the modeling region and that opens to the modeling region side;
A holder provided with the cover unit;
A drive device for controlling at least one of the position of the holder or the direction of the cover unit,
The cover unit includes an inert gas supply cover that discharges the supplied inert gas from a discharge port provided on the modeling direction side of the cover unit to the modeling area, and the modeling area when the sintered layer is formed. A fume suction cover for sucking inactive gas containing fumes generated above from a suction port provided on the side opposite to the shaping direction of the cover unit ;
The driving device is configured to at least the position of the holder or the direction of the cover unit according to the irradiation path of the laser light so that the laser light passes through the inside of the inert gas supply cover and is irradiated to the modeling region. Configured to control either one,
Additive manufacturing equipment. And the discharge port and the suction port is provided adjacent the said cover unit, layered manufacturing device of claim 1. The additive manufacturing apparatus according to claim 2 , wherein the inert gas supply cover and the fume suction cover are integrally provided in the cover unit. The irradiation end of the laser light source is provided within the holder, the drive unit moves the irradiation position of the laser beam by moving the position of the holder, according to any one of claims 1 to 3 Additive manufacturing equipment. The laser beam is configured such that the irradiation position can be controlled by an optical deflector,
The additive manufacturing apparatus according to any one of claims 1 to 4 , wherein the driving device is configured to control an orientation of the cover unit in accordance with an irradiation path of the laser light. The additive manufacturing apparatus according to any one of claims 1 to 5 , wherein the inert gas supply cover is formed so that a cross-sectional area decreases from an upper portion in the chamber toward the modeling region. The diameter of the discharge port in the inert gas supply cover is 2 of the length of the substantial sintering range of the laser beam orthogonal to the modeling direction in one scanning of the laser beam related to the formation of the sintered layer. The additive manufacturing apparatus according to any one of claims 1 to 6 , wherein the additive manufacturing apparatus is 20 times.