JP2019142017A - Additive manufacturing apparatus - Google Patents

Abstract

To provide the additive manufacturing apparatus using a powder bed fusion bonding system, that can improve quality of a product by spreading material powder at a high density and a uniform thickness.SOLUTION: The additive manufacturing apparatus comprises a material spreading part 71 that spreads material powder P while leveling the material powder, a material compression part 72 that compresses the material powder P spread by the material spreading part 71, and a surface layer removing part 73 that scrapes off a surface layer of the material powder P compressed by the material compression part 72.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an additive manufacturing apparatus.

  Conventionally, an additive manufacturing technique is known. Additive manufacturing is the process of creating an object from a numerical representation of a three-dimensional shape by depositing material, in contrast to repetitive manufacturing. Additive manufacturing is also called “3D printer” or “laminated modeling”, and is often realized by laminating a plurality of layers. As an example of an apparatus for performing addition manufacturing, the present invention relates to a powder additive manufacturing apparatus for carrying a material powder by a recoater, forming a thin layer thereof, and selectively irradiating a thin layer of the material powder with an energy beam to produce a three-dimensional structure. The invention is known (see Patent Document 1 below).

  The powder additive manufacturing apparatus described in Patent Document 1 includes a lifting platform, a first transport member and a second transport member, a pressing roller, and an energy beam emitting means for heating (the same document, claim). (See 2 etc.). The first transport member and the second transport member transport the material powder onto the lifting platform while leveling the material powder. The pressing roller is disposed between the first conveying member and the second conveying member, has a lower surface at a position lower than the lower surfaces of the first conveying member and the second conveying member, and presses the uniform material powder to form the material. A thin layer of powder is formed. The energy beam emitting means for heating heats a thin layer of material powder.

  The conventional powder additive manufacturing apparatus conveys the material powder onto the lifting platform while leveling the surface with the first conveying member or the second conveying member, and then presses the leveled material powder with a pressing roller to thin the material powder. Since a layer is formed, a thin layer of material powder with a high distribution density can be obtained. For this reason, when the thin layer is heated, melted, and solidified, the shrinkage of the volume of the thin layer can be suppressed, and thereby the shape change of the solidified layer can be suppressed (the same document, the first (See paragraph 0010 etc.).

JP, 2006-107543, A

  In the above-described conventional powder additive manufacturing apparatus, the thin layer of the material powder that has been transported and leveled by the first transport member or the second transport member is pressed by the pressing roller to improve the density distribution. However, the thin layer of the material powder pressed by the pressing roller may have a non-uniform thickness. Variations in the thickness of the thin layer of material powder may reduce the quality of the product produced by additive manufacturing.

  The present disclosure provides an additive manufacturing apparatus capable of improving the quality of a product by spreading a material powder with a high density and a uniform thickness.

  One aspect of the present disclosure is an additive manufacturing apparatus of a powder bed melt-bonding method, in which a material spreader that spreads material powder while leveling the material powder, and material compression that compresses the material powder spread by the material spreader And a surface layer removing unit that scrapes off a surface layer portion of the material powder compressed by the material compression unit.

  According to the above aspect, it is possible to provide an additional manufacturing apparatus capable of improving the quality of a product by spreading the material powder with a high density and a uniform thickness.

Sectional drawing of the addition manufacturing apparatus which concerns on one Embodiment of this indication. The perspective view of the recoater of the addition manufacturing apparatus of FIG. The side view of the material covering part, material compression part, and surface layer removal part of the addition manufacturing apparatus of FIG. The side view which shows the modification of the material covering part of FIG. 3, a material compression part, and a surface layer removal part. The side view which shows the modification of the material covering part of FIG. 3, a material compression part, and a surface layer removal part. The side view which shows the modification of the material covering part of FIG. 3, a material compression part, and a surface layer removal part. The side view which shows the modification of the material covering part of FIG. 3, a material compression part, and a surface layer removal part.

  Hereinafter, an embodiment of an additive manufacturing apparatus according to the present disclosure will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an additive manufacturing apparatus 1 according to an embodiment of the present disclosure. The additive manufacturing apparatus 1 of the present embodiment is an additive manufacturing apparatus of a powder bed fusion bonding system that manufactures a shaped article M by melting and bonding material powder P with a high energy beam B such as a laser or an electron beam.

  Although details will be described later, the powder bed fusion bonding type additive manufacturing apparatus 1 according to the present embodiment includes a material spreader 71 that spreads the material powder P while leveling the material powder, and a material powder spread by the material spreader 71. A material compressing unit 72 that compresses P, and a surface layer removing unit 73 that scrapes off the surface layer part of the material powder P compressed by the material compressing unit 72 (see FIGS. 2 and 3). Hereinafter, the structure of each part of the additional manufacturing apparatus 1 of this embodiment is demonstrated in detail.

  The additional manufacturing apparatus 1 includes, for example, a chamber 2, a decompression unit 3, a material supply unit 4, an additional manufacturing unit 5, a recovery unit 6, a recoater 7, and a beam source 8.

  The chamber 2 accommodates each part of the additive manufacturing apparatus 1 excluding the beam source 8 and the decompression part 3, for example. The chamber 2 has, for example, a transmission window 22 in which a protective glass 21 is fitted. The transmission window 22 transmits the high energy beam B irradiated from the beam source 8 arranged outside the chamber 2 and reaches the material powder P placed on the stage 51 of the additional manufacturing unit 5 inside the chamber 2. Let

  The decompression unit 3 is constituted by a vacuum pump, for example, and is connected to a vacuuming pipe 23 provided in the chamber 2. The decompression unit 3 evacuates the inside of the chamber 2 by discharging the air in the chamber 2 through, for example, the vacuuming pipe 23, thereby setting the internal pressure of the chamber 2 to a vacuum pressure reduced from the atmospheric pressure. Put it in a state.

  The material supply unit 4 is, for example, a concave part surrounded by a side wall and a bottom wall. The material supply unit 4 has a stage 41 for supplying the material powder P. The bottom wall of the material supply unit 4 is configured by a material supply stage 41. The material supply unit 4 is open at the top and has an opening at the upper end of the side wall, and the material powder P is placed on the material supply stage 41. The material supply stage 41 is provided so as to be movable up and down at a predetermined pitch by an appropriate lifting mechanism, for example.

  Although it does not specifically limit as material powder P used for addition manufacture of the molded article M, For example, powder of metal materials, such as copper, a titanium alloy, a nickel alloy, an aluminum alloy, a cobalt chromium alloy, stainless steel, resin, such as polyamide Material powder, ceramic powder, or the like can be used. The additive manufacturing apparatus 1 of the present embodiment uses, as the material powder P, for example, a metal material powder having an average particle size of about 30 μm and a particle size range of about 20 μm to about 40 μm.

  The additional manufacturing unit 5 is, for example, a concave part surrounded by a side wall and a bottom wall, like the material supply unit 4 described above. The additional manufacturing unit 5 includes a stage 51 for additional manufacturing. The bottom wall of the additional manufacturing section 5 is configured by a stage 51 for additional manufacturing. Like the material supply unit 4, the additional manufacturing unit 5 has an opening at the upper end of the side wall and an opening at the upper end of the side wall. On the stage 51 for additional manufacturing, the material powder P supplied from the material supply unit 4 and The modeled object M manufactured by addition manufacture is mounted. The opening of the additional manufacturing unit 5 and the opening of the material supply unit 4 are, for example, substantially equal in height in the vertical direction and are generally aligned in the horizontal direction. The stage 51 for additional manufacture is provided so as to be able to be raised and lowered at a predetermined pitch by, for example, an appropriate lifting mechanism, similarly to the stage 41 for material supply described above.

  The collection part 6 is a concave part surrounded by a side wall and a bottom wall, for example. In the illustrated example, the bottom wall of the recovery unit 6 is fixed to the lower end of the side wall, but may be configured by a stage that can be raised and lowered, like the material supply unit 4 and the additional manufacturing unit 5. The collection unit 6 is open at the top and has an opening at the upper end of the side wall. The opening of the collection unit 6 and the opening of the additional manufacturing unit 5 are approximately equal in height in the vertical direction and are generally aligned in the horizontal direction. The collection unit 6 accommodates and collects excess material powder P supplied from the material supply unit 4 to the additional production unit 5 by the recoater 7, for example.

  As the beam source 8, for example, an electron beam source that generates an electron beam with an output of about several kW in a vacuum or a laser light source that generates a laser with an output of about several hundred watts to several kW can be used. The beam source 8 of the additive manufacturing apparatus 1 of the present embodiment is a laser light source that generates, for example, a single mode fiber laser having a wavelength of 1080 nm and an output of 500 W, that is, a fiber laser having a Gaussian energy intensity distribution. When the beam source 8 is an electron beam source, the beam source 8 may be arranged in the chamber 2.

  FIG. 2 is a perspective view showing an example of the recoater 7 of the additive manufacturing apparatus 1 of the present embodiment. The recoater 7 includes, for example, a material spreader 71, a material compressor 72, and a surface layer remover 73. The material spreading unit 71 carries the material powder P supplied from the material supply unit 4 onto the stage 51 of the additional manufacturing unit 5 and spreads it while leveling. The material compression unit 72 compresses the material powder P spread on the stage 51 of the additional manufacturing unit 5 by the material spreading unit 71. The surface layer removing unit 73 scrapes the surface layer portion of the material powder P compressed by the material compressing unit 72 on the stage 51 of the additional manufacturing unit 5 and carries it to the collecting unit 6.

  In the additive manufacturing apparatus 1 of the present embodiment, the material spreader 71 is constituted by, for example, a plate-shaped spreader blade 71B. The material compression part 72 is comprised by the columnar or cylindrical compression roller 72R, for example. The surface layer removal part 73 is comprised by the plate-shaped removal blade 73B, for example. The spreading blade 71B, the compression roller 72R, and the removal blade 73B extend, for example, in a horizontal direction generally orthogonal to the traveling direction D.

  The laying blade 71B, the compression roller 72R, and the removal blade 73B are made of, for example, a metal material such as stainless steel or a hard material such as a ceramic material. In addition, the material of the spreading blade 71B, the compression roller 72R, and the removal blade 73B is not particularly limited, and may be made of, for example, a resin material. Further, the laying blade 71B, the compression roller 72R, and the removal blade 73B may be made of the same material, or may be made of different materials.

  In the additive manufacturing apparatus 1 of the present embodiment, the recoater 7 advances, for example, a support part 74 that supports the material spreader 71, the material compression part 72, and the surface layer removal part 73 side by side in the travel direction D, and the support part 74. And a moving mechanism 75 (see FIG. 1) for moving in the direction D. For example, the support part 74 is provided with a frame part 76 that supports the material filling part 71, the material compression part 72, and the surface layer removal part 73, and is provided at one end of the frame part 76 to support the frame part 76. And a drive unit 77 that drives the unit 72.

  The frame portion 76 extends in a direction substantially orthogonal to the traveling direction D of the recoater 7, that is, the traveling direction D of the material laying portion 71, the material compressing portion 72, and the surface layer removing portion 73, and is a rectangular box or frame having a lower end opened Shaped member. The frame portion 76 has a laying blade 71B, which is a material laying portion 71, detachably fixed to a front surface facing the front in the traveling direction D by a fastening member such as a bolt. The frame 76 has a removal blade 73B, which is a surface layer removal portion 73, detachably fixed to a back surface facing the rear in the traveling direction D by a fastening member such as a bolt.

  For example, the frame portion 76 has an adjustment mechanism 78 for adjusting the height position H1 of the tip 71a of the laying blade 71B and the height position H3 of the tip 73a of the removal blade 73B on the front surface and the back surface, respectively. Yes. In other words, the height position H1 of the tip 71a of the laying blade 71B and the height position H3 (see FIG. 3) of the tip 73a of the removal blade 73B can be adjusted by the adjustment mechanism 78, respectively. Further, the frame portion 76 can rotate the compression roller 72R constituting the material compression portion 72 by supporting both ends of the compression roller 72R by a pair of bearing portions 76a provided at both ends in the longitudinal direction, for example. I support it.

  The drive unit 77 includes a rectangular casing 77a, a motor 77b fixed to the casing 77a, and a power transmission mechanism (not shown) housed in the casing 77a. The drive unit 77 supports the frame unit 76 fixed to the housing unit 77a, and transmits the power of the motor 77b to the compression roller 72R via a power transmission mechanism housed in the housing unit 77a. Rotate. The rotation direction of the compression roller 72R is, for example, a direction facing the front in the traveling direction D of the compression roller 72R at the tip 72a of the compression roller 72R in contact with the material powder P, that is, the lower end of the compression roller 72R (see FIG. 3).

  As shown in FIG. 1, the moving mechanism 75 extends in the traveling direction D of the recoater 7 and moves the recoater 7 back and forth in the traveling direction D, for example. That is, the moving mechanism 75 moves the frame portion 76 and the driving portion 77 back and forth in the traveling direction D. As a result, the moving mechanism 75 causes the material spreader 71 supported by the frame portion 76, the material compression unit 72, the spreader blade 71B as the surface layer removal unit 73, the compression roller 72R, and the removal blade 73B to move in the traveling direction D. Move back and forth. Although the structure of the moving mechanism 75 is not specifically limited, For example, it can comprise by combining suitably each members, such as power generation parts, such as a motor, power transmission parts, such as a gear and a reduction gear, or a ball screw and a rail.

  FIG. 3 is a schematic side view of the material spreader 71, the material compressor 72, and the surface layer remover 73. In the additive manufacturing apparatus 1 of the present embodiment, the height position H2 of the tip 72a of the material compression portion 72 that contacts the material powder P is lower than the height position H1 of the tip 71a of the material laying portion 71 that contacts the material powder P. . Further, the height position H3 of the tip 73a of the surface layer removing portion 73 in contact with the material powder P is lower than the height position H2 of the tip 72a of the material compression portion 72 in contact with the material powder P. Here, the height positions H1, H2, and H3 are, for example, the height positions H1, H2, and H3 in the vertical direction, and the height positions H1, H2, and H3 from any horizontal reference plane of the additive manufacturing apparatus 1 It is.

  That is, from the front to the rear in the traveling direction D, the material laying part 71, the material compressing part 72, and the surface layer removing part 73 are arranged in this order. Further, from the front to the rear in the traveling direction D, the height position H1 of the tip 71a of the material laying portion 71, the height position H2 of the tip 72a of the material compression portion 72, and the height position of the tip 73a of the surface layer removal portion 73 H3 is gradually lower.

  Further, in the additive manufacturing apparatus 1 of the present embodiment, the laying blade 71B has an inclined surface 71b at the tip that contacts the material powder P. The inclined surface 71b is inclined with respect to the traveling direction D so that the rear side in the traveling direction D of the laying blade 71B approaches the tip 71a of the laying blade 71B. Further, in the additive manufacturing apparatus 1 of the present embodiment, the removal blade 73B has an inclined surface 73b at the tip that contacts the material powder P. The inclined surface 73b is inclined with respect to the traveling direction D so that the rear side in the traveling direction D of the removal blade 73B is away from the tip 73a of the removal blade 73B.

  In the example shown in FIG. 3, the thickness T1 in the traveling direction D of the laying blade 71B is thicker than the thickness T3 in the traveling direction D of the removal blade 73B. The thickness T1 of the spread blade 71B is not particularly limited, and may be equal to the thickness T3 of the removal blade 73B or may be thinner than the thickness T3 of the removal blade 73B.

  Hereinafter, the operation of the additive manufacturing apparatus 1 of the present embodiment will be described.

  In order to perform the additive manufacturing of the shaped article M by the additional manufacturing apparatus 1 of the present embodiment, first, the air inside the chamber 2 is discharged by the decompression unit 3, and the inside of the chamber 2 is depressurized from the atmospheric pressure to be in a vacuum state. To. Next, the stage 51 of the additional manufacturing unit 5 is lowered from the opening at the upper end of the side wall at a predetermined pitch so that a predetermined amount of the material powder P for additional manufacturing can be accommodated in the additional manufacturing unit 5.

  Next, the stage 41 of the material supply unit 4 is raised at a predetermined pitch, and a predetermined amount of the material powder P for additive manufacturing is pushed up above the opening. Next, the recoater 7 is moved forward in the traveling direction D so as to cross the opening of the material supply unit 4, and the material powder P pushed up above the opening of the material supply unit 4 is added by the recoater 7. Move to 5.

  Here, as described above, the additive manufacturing apparatus 1 of the powder bed fusion bonding method of the present embodiment includes the material spreader 71 that spreads the material powder P while leveling the material, and the material spread by the material spreader 71. A material compressing unit 72 that compresses the powder P and a surface layer removing unit 73 that scrapes off the surface layer of the material powder P compressed by the material compressing unit 72 are provided.

  With this configuration, as shown in FIG. 3, the material powder P is first averaged by the material laying part 71 on the stage 51 of the additional manufacturing part 5 at a thickness Tp1 that is thicker than the target thickness Tp3 of the material powder P. While laying down. Furthermore, the material powder P spread by the material spreader 71 can be compressed by the material compression unit 72. Thereby, the material powder P can be compressed on the stage 51 of the additional manufacturing unit 5 to a thickness Tp2 that is thinner than the thickness Tp1, thereby improving the density distribution. Therefore, the material powder P can be spread on the stage 51 of the additional manufacturing unit 5 with high density.

  However, while the material powder P is compressed, the density is improved. On the surface layer portion of the compressed material powder P, for example, uneven shapes such as irregularities, undulations, or streaks may be formed. . In such a case, with the conventional powder bed fusion bonding type additive manufacturing apparatus, the thickness of the spread material powder becomes uneven, and the quality of the product manufactured by melting and bonding the spread material powder is improved. May decrease.

  On the other hand, the additive manufacturing apparatus 1 of this embodiment includes the surface layer removing unit 73 that scrapes off the surface layer portion of the material powder P compressed by the material compressing unit 72 as described above. Thus, even when a non-uniform shape such as irregularities is formed on the surface layer portion of the material powder P compressed by the material compression portion 72, the surface layer portion of the material powder P can be scraped off by the surface layer removing portion 73.

  Therefore, according to the additive manufacturing apparatus 1 of the present embodiment, while maintaining the high density of the compressed material powder P, it is thinner than the thickness Tp2 of the compressed material powder P, and has an extremely flat and uniform thickness Tp3. Thus, the material powder P can be spread on the stage 51 of the additional manufacturing section 5. Further, excess material powder conveyed to the collecting unit 6 by the material spreader 71 and the surface layer removing unit 73 is introduced into the opening of the collecting unit 6, accommodated in the collecting unit 6 and collected.

  Next, based on the three-dimensional shape data of the model M, a high energy such as a laser or an electron beam is applied from the beam source 8 to a predetermined region of the material powder P placed on the stage 51 of the additional manufacturing unit 5. Irradiate beam B. As a result, the material powder P in a predetermined region is melt-bonded to form a part of the shaped object M. At this time, the material powder P is spread on the stage 51 of the additional manufacturing unit 5 at a high density and a uniform thickness Tp3 by the material spreading unit 71, the material compression unit 72, and the surface layer removing unit 73.

  Thereby, it is possible to prevent unintended cavities and irregularities from being generated in a part of the model M formed by melting and bonding the material powder P. Thereafter, the recoater 7 is moved backward in the traveling direction D by the moving mechanism 75 to return to the original position, and the above-described procedure is repeated again. Thereby, the high-quality molded object M with few defects can be manufactured with high accuracy based on the three-dimensional shape data. Therefore, according to the present embodiment, it is possible to provide the additional manufacturing apparatus 1 capable of improving the quality of the product by spreading the material powder P on the high-density and uniform thickness Tp3.

  Note that the additive manufacturing apparatus 1 of the present embodiment can also exhibit an excellent effect even when the metal powder having a variation in particle diameter is used as the material powder P as described above. More specifically, as the material powder P, a metal material powder having an average particle diameter of about 30 μm and a particle diameter range of about 20 μm to about 40 μm is used, and the material powder P has a uniform thickness of about 40 μm. The case where powder P is spread on the stage 51 of the additional manufacturing part 5 is assumed.

  In this case, in the conventional powder additive manufacturing apparatus, the material powder is carried on the lifting platform while the surface is leveled by the first conveying member or the second conveying member, and then the leveled material powder is pressed by the pressing roller to form the material. A thin layer of powder is formed. However, it is extremely difficult to adjust the material powder P as described above to a uniform thickness of about 40 μm by pressing it with a pressing roller. For this reason, the thin layer of the material powder P spread by the conventional powder additive manufacturing apparatus is interrupted in some places or the material powder P is locally gathered, resulting in a very uneven state.

  On the other hand, the additional manufacturing apparatus 1 of this embodiment compresses the material powder P spread on the stage 51 of the additional manufacturing unit 5, and the thickness Tp2 of the material powder P is the target material powder P. It is thicker than the thickness Tp3. Then, the surface layer portion of the material powder P whose density after compression has been increased is scraped off by the surface layer removing portion 73, so that the thickness Tp3 of the material powder P is a uniform thickness of about 40 μm which is thinner than the thickness Tp2 after compression. Can be adjusted.

  Therefore, the additive manufacturing apparatus 1 of the present embodiment can improve the density of the material powder P by compression and improve the density of the material powder P by about 40 μm even when the material powder P having a variation in particle diameter as described above is used. It can be spread on the stage 51 of the additional manufacturing section 5 with a uniform thickness Tp3. Thereby, while reducing the cost of the material powder P, a high-quality molded article M can be manufactured as a product.

  In addition manufacturing apparatus 1 of this embodiment, as mentioned above, height position H2 of tip 72a of material compression part 72 is lower than height position H1 of tip 71a of material laying part 71. . In addition, the height position H3 of the tip 73a of the surface layer removal unit 73 is lower than the height position H2 of the tip 72a of the material compression unit 72.

  With this configuration, the additive manufacturing apparatus 1 according to this embodiment allows the material powder P having a thickness Tp1 laid by the material laying portion 71 to be thinned by the material compression portion 72 to a thickness Tp2 that is thinner than the thickness Tp1. And the density of the material powder P can be improved. Furthermore, the surface layer portion of the material powder P having the thickness Tp2 compressed by the material compressing portion 72 can be scraped off by the surface layer removing portion 73 to a thickness Tp3 that is smaller than the thickness Tp2. Therefore, it is possible to improve the quality of the product by spreading the material powder P in a high density and uniform thickness Tp3.

  In addition manufacturing material 1 of this embodiment, material spread part 71 is constituted by plate-shaped spread blade 71B. Thereby, the structure of the material covering part 71 can be simplified, and replacement | exchange and a maintenance can be made easy. Further, by moving the plate-shaped spreader blade 71B forward in the traveling direction D, the material powder P on the stage 41 of the material supply unit 4 is pushed onto the stage 51 of the additional manufacturing unit 5 by the spreader blade 71B. It can be carried and leveled.

  Moreover, in the additive manufacturing apparatus 1 of this embodiment, the material compression part 72 is comprised by the compression roller 72R, and the surface layer removal part 73 is comprised by the plate-shaped removal blade 73B. With this configuration, the material powder P spread on the stage 51 of the additional manufacturing unit 5 by the material spreader 71 can be reliably and stably compressed by the compression roller 72R, and the material powder P is compressed to a high density. can do. Further, the surface layer portion of the material powder P compressed at high density can be accurately and uniformly scraped by the plate-shaped removal blade 73B. The compression roller 72R can be fixed without being rotated, but can be more stably compressed by being rotated.

  Further, in the additive manufacturing apparatus 1 of the present embodiment, the laying blade 71B has an inclined surface 71b at the tip that contacts the material powder P. The inclined surface 71b is inclined with respect to the traveling direction D so that the rear side in the traveling direction D of the laying blade 71B approaches the tip 71a of the laying blade 71B. With this configuration, the material powder P leveled and spread on the stage 51 of the additional manufacturing unit 5 by the spreader blade 71B is moved by the inclined surface 71b to the stage 51 by the forward movement of the spreader blade 71B in the traveling direction D. It is pressed and compressed toward. Thereby, the density of the material powder P can be improved by the spreading blade 71B.

  Further, in the additive manufacturing apparatus 1 of the present embodiment, the removal blade 73B has an inclined surface 73b at the tip that contacts the material powder P. The inclined surface 73b is inclined with respect to the traveling direction D so that the rear side in the traveling direction D of the removal blade 73B is away from the tip 73a of the removal blade 73B. With this configuration, the density is increased by being compressed by the compression roller 72R, and the surface of the material powder P after the surface layer portion is scraped off by the removal blade 73B is prevented from being disturbed. The material powder P can be spread with a more uniform thickness Tp3.

  More specifically, the inclined surface 73b at the tip of the removal blade 73B can form a relief on the rear side in the traveling direction D of the tip 73a of the removal blade 73B in contact with the material powder P. Thereby, after the surface layer portion of the material powder P is scraped off by the tip 73a corresponding to the cutting edge of the removal blade 73B, the surface of the material powder P is prevented from contacting a part of the removal blade 73B with the material powder P. Can be prevented. Therefore, the material powder P can be spread on the stage 51 of the additional manufacturing unit 5 with a more uniform thickness Tp3.

  Further, the additive manufacturing apparatus 1 of this embodiment includes a support portion 74 that supports the material filling portion 71, the material compression portion 72, and the surface layer removal portion 73 side by side in the traveling direction D, and moves the support portion 74 in the traveling direction D. And a moving mechanism 75 to be moved. With this configuration, the material spreader 71, the material compression unit 72, and the surface layer removal unit 73 can be simultaneously moved in the traveling direction D, and the material powder P can be spread, compressed, and scraped off the surface layer portion continuously. . Moreover, it is not necessary to provide a separate moving mechanism for the material spreader 71, the material compressing unit 72, and the surface layer removing unit 73, and the configuration of the additive manufacturing apparatus 1 can be simplified.

  As described above, according to the present embodiment, the material powder P is spread on the stage 51 of the additive manufacturing unit 5 at a high density and a uniform thickness Tp3, thereby improving the quality of the shaped object M that is a product. Can be provided. In addition, the additional manufacturing apparatus of this indication is not limited to the structure of the additional manufacturing apparatus 1 which concerns on above-mentioned embodiment. Hereinafter, modifications of the additive manufacturing apparatus 1 according to the above-described embodiment will be described.

  In the additive manufacturing apparatus 1 according to the above-described embodiment, the laying blade 71B may have an elastic portion 71c (see FIG. 2) that can be elastically deformed at a tip portion in contact with the material powder P. For example, the elastic part 71c can be formed in the front-end | tip part of the spread blade 71B by providing a some slit in the front-end | tip part of the spread blade 71B, and making the front-end | tip part of the spread blade 71B into a comb-tooth shape.

  That is, the elastic part 71c of the laying blade 71B is configured to be elastically deformed more easily than the other parts of the laying blade 71B. With such a configuration, when the material powder P is spread on the stage 51 of the additional manufacturing unit 5 by the spread blade 71B while being leveled, the breakage of the spread blade 71B or the model M can be prevented.

  More specifically, in a state where a part of the model M is formed on the stage 51 of the additional manufacturing unit 5, the material powder P is spread on the stage 51 of the additional manufacturing unit 5 while being leveled by the laying blade 71B. There is a case. At this time, even if the tip of the laying blade 71B is caught by a part of the molded article M, the elastic portion 71c is elastically deformed to prevent an excessive force from acting on the laid blade 71B or the molded article M. As a result, the laying blade 71B or the model M can be prevented from being damaged. In addition, the same effect can be show | played by providing the same elastic part 73c (refer FIG. 2) in the front-end | tip part of the removal blade 73B.

  FIG. 4 is a schematic side view corresponding to FIG. 3 and showing another modified example of the material filling unit 71, the material compressing unit 72, and the surface layer removing unit 73 of the additive manufacturing apparatus 1 according to the above-described embodiment. The spreader blade 71B constituting the material spreader 71 may not have the inclined surface 71b at the tip, and the remover blade 73B constituting the surface layer removing unit 73 does not have the inclined surface 73b at the tip. May be.

  In this case, the compressing effect of the material powder P by the laying blade 71B cannot be obtained, but it is possible to spread the material powder P while leveling the laying blade 71B. Further, the removal blade 73B is configured to reduce the thickness T3 as much as possible within a range where necessary rigidity can be obtained, so that the surface layer portion of the material powder P is uniformly scraped while preventing the surface disturbance of the material powder P. Can do.

  FIG. 5 is a schematic side view corresponding to FIG. 3 and showing another modification of the material spreader 71, the material compressor 72, and the surface layer remover 73 of the additive manufacturing apparatus 1 according to the above-described embodiment. The material laying portion 71 may be constituted by, for example, a laying roller 71R. For example, the laying roller 71R may be rotated in the same rotational direction as the compression roller 72R. With this configuration, the material powder P supplied from the material supply unit 4 is transported onto the stage 51 of the additional manufacturing unit 5 and spread while being leveled by the laying roller 71R, and at the same time, the material powder P is compressed to reduce the density. Can be improved. Note that. The laying roller 71R may be fixed so as not to rotate.

  6 is a schematic side view corresponding to FIG. 3 and showing another modification of the material spreader 71, the material compressor 72, and the surface layer remover 73 of the additive manufacturing apparatus 1 according to the above-described embodiment. The material compression unit 72 may include a pressing unit 72P that presses the compression roller 72R against the material powder P, for example. The pressing portion 72P can be constituted by, for example, a bearing portion that rotatably supports the compression roller 72R and a spring that applies a force to the bearing portion. With such a configuration, it is possible to compress the material powder P more uniformly by pressing the compression roller 72R against the surface of the material powder P with a force according to the surface state of the material powder P.

  FIG. 7 is a schematic side view corresponding to FIG. 3 and showing another modification example of the material filling unit 71, the material compression unit 72, and the surface layer removal unit 73 of the additive manufacturing apparatus 1 according to the above-described embodiment. For example, the removal blade 73B constituting the surface layer removing portion 73 is inclined so as to recede in the advancing direction D as it moves away from the tip portion in contact with the material powder P, and the angle A between the surface layer portion of the material powder P is It has an acute angle. With such a configuration, the surface layer portion of the material powder P can be scraped off and the material powder P can be made to have a more uniform thickness Tp3.

  The embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Additional manufacturing apparatus 71 Material laying part 71a Tip 71B laying blade 71b Inclined surface 72 Material compression part 72a Tip 72P Pressing part 72R Compression roller 73 Surface layer removal part 73a Tip 73B Removal blade 73b Inclined surface 74 Support part 75 Moving mechanism A Angle D Traveling direction H1 Height position H2 Height position H3 Height position P Material powder

Claims (10)

An additive manufacturing apparatus of powder bed fusion bonding method,
A material laying section that spreads the material powder while leveling,
A material compression section that compresses the material powder spread by the material spread section;
An additive manufacturing apparatus comprising: a surface layer removing unit that scrapes off a surface layer portion of the material powder compressed by the material compressing unit. The height position of the tip of the material compression part is lower than the height position of the tip of the material laying part,
The additive manufacturing apparatus according to claim 1, wherein a height position of a tip of the surface layer removing unit is lower than a height position of the tip of the material compression unit.   3. The additive manufacturing apparatus according to claim 2, wherein the material laying portion is configured by a plate-like laying blade. The laying blade has an inclined surface at a tip portion in contact with the material powder,
4. The additive manufacturing apparatus according to claim 3, wherein the inclined surface is inclined with respect to the advancing direction so that a rear side in the advancing direction of the laying blade is closer to a tip of the laying blade. .   The additive manufacturing apparatus according to claim 3, wherein the laying blade has an elastic portion that can be elastically deformed at a tip portion in contact with the material powder. The material compression unit is constituted by a compression roller,
The additive manufacturing apparatus according to claim 2, wherein the surface layer removing unit is configured by a plate-shaped removing blade.   The additive manufacturing apparatus according to claim 6, wherein the material compression unit includes a pressing unit that presses the compression roller against the material powder.   The removal blade is inclined so as to recede backward in the advancing direction as it moves away from a tip portion in contact with the material powder, and an angle between the removal blade and a surface layer portion of the material powder is an acute angle. The additional manufacturing apparatus described in 1. The removal blade has an inclined surface at a tip portion in contact with the material powder,
7. The additive manufacturing apparatus according to claim 6, wherein the inclined surface is inclined with respect to the traveling direction so as to be farther away from the tip of the removing blade toward the rear side in the traveling direction of the removing blade. A support portion that supports the material spreading portion, the material compression portion, and the surface layer removal portion side by side in the traveling direction;
The addition manufacturing apparatus according to claim 1, further comprising a moving mechanism that moves the support portion in the traveling direction.