JP2015157405A - Laminate molding method and laminate molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce waste of a powder material.SOLUTION: A powder supply device 6 distributes a material powder at belt like per each layer where desired products are divided into a plurality of layers. A uniformizing device 7 uniformizes the distributed material powder according to set thickness t and forms a powder layer having a predetermined height. A laser irradiation device 8 solidifies by sintering the powder layer by scanning a laser light on distribution of the material powder with tracking and forms sintered layer. Belt-like sintered layers are combined for each layer and sintered layers in a predetermined molding region defined by a planar shape are formed, and sintered layers in each layer are laminated to obtain a desired article.

Description

  The present invention is an additive manufacturing method for generating a metal article having a desired shape by dividing an article having a desired shape into a plurality of layers and superimposing each layer while forming the shape of each layer in order from the lowest layer. And an additive manufacturing apparatus. In particular, the present invention relates to a layered modeling method and a layered modeling apparatus that generate a metal article by a powder layering method.

  Generation of an article by three-dimensional modeling is basically performed by an additive manufacturing method. A powder laminating method in which the material powder is solidified into a desired shape and laminated, in particular, a method of forming the shape by sintering the material powder with high-energy laser light, or, for example, by using an electron beam It is known that a metal article can be produced by a method of forming a shape by melting and immediately solidifying a body. In the present invention, a method of forming a shape by sintering material powder with laser light is called a powder sintering lamination method. A method of forming a shape by melting and solidifying material powder by electron collision is called a powder melt lamination method.

  The processing of the three-dimensional metal is performed exclusively by cutting or electric discharge machining. In the present invention, “processing” refers to an operation of removing material. On the other hand, “modeling” refers to an operation of adding a material. Processing and modeling have merits and demerits in producing articles. Nevertheless, due to the inherent differences in the process of operation in each of processing and modeling, three-dimensional modeling has several advantages that cannot be obtained with three-dimensional processing.

  For example, in modeling, there is no tool that is indispensable for processing, and therefore, an operation of preparing a plurality of tools or exchanging tools is not required. Therefore, from a comprehensive point of view, it can be expected to shorten the time until an article having a similar three-dimensional shape is generated as compared with the case of processing an arbitrary three-dimensional shape. Further, according to the three-dimensional modeling, it is possible to form a part that is difficult to be processed without being able to reach the tool.

  In the following description, modeling of a metal article by a powder sintering lamination method will be described unless otherwise specified. In the present invention, a layer of material powder obtained by spreading a material powder for each layer obtained by dividing a desired article into a plurality of layers and then leveling to a predetermined height is called a powder layer. A portion formed by solidification by sintering is referred to as a sintered layer. Moreover, the site | part formed by melt-solidifying among powder layers is called a melt-solidified layer. In addition, let the powder layer or sintered layer of the lowest layer used as the foundation of the articles | goods produced | generated be the 1st layer of several layers.

  The thickness of the powder layer is approximately 50 μm when the material powder is copper having an average particle diameter of 30 μmφ. When the average particle size of the material powder is different, the thickness of the powder layer that can be sintered by one irradiation of laser light with the same energy changes. In addition, when the material of the article to be produced is an alloy such as brass or cemented carbide (including cobalt as a binder), depending on the average particle diameter or mixing ratio of the mixed metal material powder, The thickness of the powder layer that can be reliably sintered can be different. Therefore, in the present invention, the set thickness of the powder layer is assumed to be in the range of 30 μm to 100 μm.

  When three-dimensional modeling is performed by the powder sintering lamination method, solid data of a desired article created by, for example, a three-dimensional computer-aided design system (CAD) is determined in advance before modeling. It is divided into a plurality of layers so as to be sliced by thickness, and planar shape data is obtained for each layer, and the scanning path of the laser beam is calculated.

  At the time of modeling, the material powder is distributed over the entire area of the modeling chamber formed of a frame body by the powder supply device for each layer, and then uniformized to a predetermined height by a homogenizing device. After forming a powder layer having a thickness of, a scan is performed while irradiating a laser beam along a predetermined scanning path, and only a predetermined modeling region that becomes an article is selectively sintered.

  In Patent Document 1, a material powder having a predetermined average particle diameter is distributed for each layer obtained by dividing a desired article into a plurality of layers, and the distributed material powder has a predetermined thickness. After forming a powder layer to a height corresponding to the thickness, each layer is irradiated with a laser beam in accordance with the planar shape of each layer, and a sintered layer is laminated to form an article having a desired shape. An additive manufacturing method for generating is disclosed.

  As typically disclosed in Patent Document 2 and Patent Document 3, a general additive manufacturing apparatus that performs desired three-dimensional modeling by a powder lamination method includes a material powder having a predetermined average particle diameter. A so-called squeezing device having a powder supply device for distributing the powder on a table or a base plate placed on the table, and a member for leveling the distributed material powder called a blade or wiper to a predetermined height Is provided. According to the inventions of Patent Document 2 and Patent Document 3, a sintered layer is more reliably laminated by forming a powder layer having a uniform height and irradiating a required portion with a laser beam or an electron beam. Can do.

  Therefore, in a general additive manufacturing apparatus, most of the distributed material powder remains in the modeling room without being directly involved in the production of the article. Although it is possible to recover the remaining material powder, not all are left in a reusable state. Therefore, it is necessary to separate and collect the reusable material powder and the non-reusable material powder, which causes a reduction in work efficiency. In addition, it is required to always prepare extra material powder in an amount sufficiently larger than the material powder directly used for the article. In particular, when a relatively expensive metal material powder having a high rare value is included, it is desired not to generate a waste material powder that cannot be reused as much as possible.

  In addition, since the excess powder material that is distributed outside the modeling area is accumulated and remains in the modeling chamber in a large amount while the layers are stacked, the average particle diameter or material is different during the modeling. It is not easy to replace the material powder. Therefore, for example, in order to shorten the modeling time, the average grain is selectively averaged while sintering and laminating a portion having a large surface roughness required using a material powder having a relatively large average particle diameter. It is not possible to easily adopt a modeling technique such as laminating a portion having a small surface roughness required using a material powder having a relatively small diameter.

  Patent Document 4 discloses a layered modeling method in which a required modeling region is specified for each layer obtained by dividing a desired article into a plurality of layers, and material powder is locally supplied to the specific modeling region. Yes. Specifically, the invention of Patent Document 4 is a raw material storage tank that stores material powder that can move to a specific modeling area, and a squeezing that can change the width according to the size of the specific modeling area. With a blade.

  Patent Document 5 discloses an additive manufacturing apparatus provided with both side frames for leveling the material powder to be dropped while moving in the horizontal direction, and a partition plate for restricting a modeling area between the both side frames. Disclosure. According to the invention of Patent Document 5, the width of the material powder supplied to the predetermined modeling area by preventing the material powder from flowing in the longitudinal direction at the end of the predetermined modeling area where the material powder is supplied. And waste of material powder can be reduced.

JP-T-1-502890 JP-A-8-281807 JP-A-6-192702 JP 2012-246541 A JP 2007-216595 A

  When supplying a material powder by limiting to a predetermined modeling area specified for each layer obtained by dividing a desired article into a plurality of layers, sufficiently enclose a predetermined modeling area having an arbitrary planar shape. It is necessary to distribute the material powder in a wider rectangular area to obtain. Therefore, there is room for reducing the amount of material powder to be distributed. In addition, as the amount of the material powder to be distributed is reduced, the powder layer is spread compared to the case where the material powder is distributed all over the modeling chamber surrounded by the powder and leveled at a predetermined height. It takes extra time to form, which may reduce the work efficiency.

  In view of the above problems, it is a primary object of the present invention to provide an improved additive manufacturing method and additive manufacturing apparatus capable of reducing the amount of material powder to be distributed. In addition, when the material powder is locally distributed and solidified, it is a lamination that does not reduce the efficiency of the work from distributing the material powder to sintering or melting and solidifying the material powder as much as possible. An object is to provide a modeling method and an additive manufacturing apparatus. Other advantages of the additive manufacturing method and additive manufacturing apparatus of the present invention will be described in detail in the description of specific embodiments.

  In order to solve the above problems, the additive manufacturing method of the present invention distributes a material powder in a strip shape for each layer obtained by dividing a desired article into a plurality of layers, and the powder material distributed in a strip shape is applied to each layer. A powder layer having a predetermined height is formed according to a predetermined thickness every time, and the powder layer is solidified by following the distribution of material powder to form a sintered layer or a melt-solidified layer in a band shape. By combining the belt-like sintered layer or the melt-solidified layer every time to obtain a sintered layer or a melt-solidified layer of a predetermined modeling region, the sintered layer or the melt-solidified layer of the predetermined modeling region of each layer is laminated to obtain a desired layer Get an article.

  The layered manufacturing method is preferably a band-like sintered layer or while irradiating a laser beam or an electron beam repeatedly reciprocating within a predetermined distance in a direction perpendicular to the advancing direction in which the powder layer is solidified. A melt-solidified layer is formed.

  The additive manufacturing apparatus of the present invention includes a powder supply device (6) for distributing a material powder in a strip shape for each layer obtained by dividing a desired article into a plurality of layers, and a belt shape following the powder supply device (6). The homogenizing device (7) for forming the belt-like powder layer by leveling the material powder spread on the layer according to the set thickness of each layer to form a belt-like powder layer, and leveling the belt following the homogenizing device (7) And a laser irradiation device (8) for forming a belt-like sintered layer by sintering the powder layer.

  The additive manufacturing apparatus is preferably a powder storage box (7A) of a powder supply device (7), a blade (7A) of a homogenizing device (7), and a laser irradiator (8A) of a laser irradiation device (8). Are moved together in synchronism with one horizontal axis direction, another horizontal one axis direction orthogonal to the horizontal one axis direction, and one vertical axis direction orthogonal to each horizontal one axis direction. In addition, there is provided a modeling head (2) that rotates horizontally around a vertical axis so that the rotation angle can be indexed in synchronization with each axial direction.

  More preferably, the layered manufacturing apparatus is configured so that the laser irradiator (8A) reciprocates within a predetermined distance in a direction orthogonal to the traveling direction. Desirably, the fall prevention body (2C) is in close contact with the edge so that the material powder supplied from the powder feeding device (6) by the modeling head (2) does not fall freely from the edge of the modeled object during modeling. To include.

  In addition, the code | symbol shown by the said parenthesis is attached | subjected for convenience of explanation, Comprising: It does not limit this invention to the additive manufacturing method and additive manufacturing apparatus of embodiment specifically shown by drawing. Absent.

  The layered manufacturing method of the present invention distributes the material powder in a band shape for each layer and makes the height of the distributed material powder uniform, and follows the material powder distribution to form a sintered layer or a melt-solidified layer in a band shape. Therefore, the amount of material powder to be distributed can be reduced. Therefore, the cost required for the material powder can be reduced. Moreover, the burden of the operation | work which collect | recovers material powder in order to reuse the remaining material powder is reduced. In addition, it is possible to more easily exchange material powders having different average particle sizes or materials during modeling, and more efficient modeling can be performed.

  The additive manufacturing apparatus of the present invention includes a powder supply device that distributes material powder in a strip shape, and a homogenizer that forms a belt-like powder layer by leveling the material powder to a predetermined height following the powder supply device. And a laser irradiation device that sinters and solidifies the powder layer following the homogenizing device, so that the powder layer and the sintered layer can be formed almost simultaneously, and the material powder is spread throughout the modeling chamber. Compared to the case of distributing and modeling, the work efficiency is not reduced so much. In addition, since material powder is not distributed throughout the modeling room, there is no need to move the frame that forms the table, base plate, or modeling room as the modeling progresses, and the overall configuration of the additive manufacturing apparatus is simplified. Can be.

  In particular, in the additive manufacturing apparatus according to the present invention in which the laser irradiator is attached to the tracking head integrally with the powder storage box in which the material powder is distributed in a band shape, it follows the powder storage box movable in the three-dimensional direction. The drive source of the laser irradiator can be shared, the positional relationship between the powder storage box and the laser irradiator can be maintained without positioning control, and the overall configuration of the additive manufacturing apparatus can be simplified. Can do. Moreover, when combining and implementing three-dimensional shaping | molding and three-dimensional processing like cutting, it becomes possible to share the drive source of the shaping | molding head in lamination molding, and the processing head in cutting.

It is a perspective view showing typically the basic composition of the additive manufacturing apparatus which performs the additive manufacturing method of the present invention partially. 1 is a perspective view partially showing an outline of an embodiment of an additive manufacturing apparatus of the present invention. It is a bottom view which shows the principal part of the modeling head of embodiment shown by FIG. It is a perspective view of the modeling head shown by FIG. It is a top view which shows the relative movement locus | trajectory of the modeling head shown by FIG. It is a right view which shows the principal part of the modeling head shown by FIG. It is a front view which shows the principal part of the modeling head shown in FIG. 3 when located in the edge of the modeling object in the middle of modeling. It is a front view which shows the principal part of the modeling head shown by FIG. 3 when moving the upper surface of the modeling object in the middle of modeling. It is a top view which shows the principal part of the modeling head at the time of linear movement. It is a top view which shows the principal part of the modeling head at the time of curve movement. It is a top view which shows the principal part of a modeling head when a laser irradiation device reciprocates.

  FIG. 1 shows a basic configuration of an additive manufacturing apparatus capable of implementing the additive manufacturing method of the present invention. FIG. 1 shows the additive manufacturing apparatus in a partially cut state. The layered manufacturing apparatus shown in FIG. 1 flattens the metal material powder in a band shape for each layer to a uniform height, and follows the formation of the band-shaped powder layer to sinter a predetermined modeling area. By repeating the above, a metal article is generated.

  As shown in FIG. 1, the additive manufacturing apparatus 1 includes a modeling head 2, a modeling head 2 in a horizontal uniaxial direction, another horizontal uniaxial direction orthogonal to the horizontal uniaxial direction, and these horizontal biaxial directions. A moving device 3 that moves in three simultaneous axial directions with a vertical one-axis direction orthogonal to the table, a table 4 set on a base (not shown), and a modeling chamber 5 formed in the table 4 are provided. The layered manufacturing apparatus 1 is also configured to form a belt-like powder layer by leveling a powder supply device 6 that spreads the material in a strip shape and a material powder spread in a strip shape to a predetermined height according to the installation thickness of each layer. And a laser irradiation device 8 that forms a belt-like sintered layer by sintering the powder layer scheduled in the belt-like shape following the homogenizing device 7.

  A laser irradiation apparatus 8 of the additive manufacturing apparatus 1 shown in FIG. 1 includes a laser irradiator 8A, a laser oscillator 8B as a light source, and a scanning apparatus 8C including a plurality of reflection apparatuses and a condensing apparatus. The scanning device 8C that scans the laser beam is an optical system that deflects and scans the laser beam with a galvanometer mirror. The scanning device 8 </ b> C scans the laser beam in a direction orthogonal to the installation direction of the upper beam 1 </ b> A of the additive manufacturing apparatus 1 and irradiates an arbitrary position. Further, the scanning device 8 </ b> C that is a laser head can reciprocate along the installation direction of the upper beam 1 </ b> A of the additive manufacturing apparatus 1, and can irradiate laser light from an arbitrary position on the upper beam 1 </ b> A.

  The basic process of the additive manufacturing method of the present invention by the additive manufacturing apparatus 1 is as follows. First, the modeling head 2 is moved in two horizontal axes, and a powder supply device 6 provided on the modeling head 2 is used to divide a desired article into a plurality of layers and distribute the material powder in a strip shape. To do.

  By moving the homogenizer 7 provided in the modeling head 2 so as to follow the powder supply device 6, the thickness of the material powder distributed in a strip shape by the homogenizer 7 is predetermined for each layer. To form a powder layer having a predetermined height.

  By operating the laser irradiation device 8 or the electron beam irradiation device following the movement of the homogenizing device 7, the laser beam or the electron beam is scanned and irradiated so as to follow the powder layer formed in a band shape. The powder layer is solidified by following the powder distribution to form a sintered layer or a melt-solidified layer in a band shape. Then, a belt-like sintered layer or melt-solidified layer is combined for each layer to obtain a sintered layer or melt-solidified layer in a predetermined modeling area, and a sintered layer or melt-solidified layer in a predetermined modeling area of each layer is laminated. To obtain a desired article.

  2 and 3 show a suitable embodiment of the additive manufacturing apparatus of the present invention. The additive manufacturing apparatus shown in FIG. 2 includes the same means as the additive manufacturing apparatus shown in FIG. However, the additive manufacturing apparatus of the embodiment shown in FIG. 2 is different from the additive manufacturing apparatus of the basic configuration shown in FIG. 1 in that the laser irradiation device of the laser irradiation apparatus is attached to the formation head.

  Hereinafter, the additive manufacturing apparatus 1 according to a suitable embodiment will be described in detail with reference to FIGS. 2 to 11 as appropriate. The additive manufacturing apparatus 1 according to the embodiment shown in FIG. 2 spreads a metal material powder for each layer, leveles it to a uniform height to form a belt-like powder layer, and high-power laser light is applied to the powder layer. Is repeated to sinter a predetermined modeling area, thereby generating a metal three-dimensional shaped article. In the additive manufacturing apparatus 1 shown in FIG. 2, the surface located on the left hand side in the drawing is the front surface, the surface located on the right side with respect to the front surface is the right side surface, the surface located on the left side with respect to the front surface is the left side surface, The surface located opposite to the front surface is the back surface.

  In the modeling head 2 of the additive manufacturing apparatus 1 of the embodiment shown in FIG. 2, the surface positioned in the direction in which the modeling head 2 relatively advances is the front surface, and the surface positioned opposite to the front surface is the rear surface. A surface located on the right side in the direction in which the head 2 moves forward is a right side surface, and a surface located on the left side is a left side surface. Note that the direction in which the modeling head 2 moves forward coincides with the direction in which modeling proceeds, so the direction in which the modeling head 2 moves forward is simply referred to as the traveling direction unless otherwise specified.

  As shown in detail in FIGS. 3 and 4, the modeling head 2 advances the powder storage box 6 </ b> A of the powder supply device 6, the blade 7 </ b> A of the homogenizing device 7, and the laser irradiator 8 </ b> A of the laser irradiation device 8. It is an assembly that is arranged in order on a straight line from the front side along the direction and is integrally attached to the housing 2A. The housing 2A of the modeling head 2 is inserted with a through hole through which the metal material powder that freely falls from the powder storage box 6A passes, a through hole through which the blade 7A passes (both not shown), and a laser irradiator 8A. A long hole 2B is provided.

  The modeling head 2 is moved by the moving device 3 in the horizontal uniaxial direction (left-right direction) in the additive manufacturing apparatus 1, another horizontal uniaxial direction (front-rear direction) orthogonal to the horizontal uniaxial direction, and each horizontal uniaxial direction. Is moved relative to the modeling chamber 5 of the additive manufacturing apparatus 1 in synchronism with a vertical one-axis direction (vertical direction) perpendicular to the vertical direction. Further, the modeling head 2 rotates and moves horizontally around the vertical axis so that the rotation angle can be indexed in synchronization with each axis.

  The modeling head 2 includes a fall prevention body 2C. The fall prevention body 2C is an elastic body that is in close contact with the edge of the modeled object so that the material powder supplied from the powder supply device 6 does not fall freely from the edge of the modeled object (sintered body) being modeled. The fall prevention body 2 </ b> C is desirably chamfered on the front surface of the modeling head 2 for smooth advancement of the modeling head 2. The fall prevention body 2C is detachable and is attached to at least one of the left and right sides of the modeling head 2 and is attached to the left and right sides of the modeling head 2 as necessary.

  The fall prevention body 2C has a relatively large amount of distortion that can be deformed so as not to form a gap with the edge of the modeled object when pressed against the edge of the modeled object in accordance with the contour shape of the modeled object in the middle of modeling. It is formed by the material. Further, the surface of the fall prevention body 2C is smoothly formed so as to minimize the frictional force generated between the fall prevention body 2C and the edge of the modeled object. Specifically, the fall prevention body 2C provided in the modeling head 2 of the additive manufacturing apparatus 1 according to the embodiment is, for example, a so-called sponge having a sufficiently high fiber density and a smooth surface.

  As shown in FIGS. 6 and 7, the fall prevention body 2 </ b> C is provided to project downward by a predetermined projection amount h from the outer frame of the housing 2 </ b> A. Further, as shown in FIG. 7, the fall prevention body 2 </ b> C can be deformed upward with a protrusion amount h or less. The predetermined protruding amount h is desirably a value that is slightly larger than a predetermined thickness t of the powder layer PL or the sintered layer SL. The fall prevention body 2C can be moved up and down in accordance with the set thickness t of the sintered layer SL by an actuator such as an electrostrictive material.

  The moving device 3 includes a plurality of moving bodies, and relatively moves the modeling head 2 in a three-dimensional arbitrary direction by synchronizing and reciprocating each moving body in a predetermined direction. The moving device 3 includes a control device (not shown). The control device inputs a detection signal of a position detector provided for each moving body and controls a servo motor that moves each moving body. Specifically, each moving body of the moving device 3 is a top beam 31, a slider 32, a quill 33, and a rotor 34.

  As shown in FIG. 2, the top beam 31 reciprocates in a horizontal uniaxial direction corresponding to the left and right direction of the additive manufacturing apparatus 1 by a servo motor 31 </ b> A composed of a pair of linear motors. In the additive manufacturing apparatus 1 of the embodiment, for the sake of convenience, the control axis in the left-right direction of the additive manufacturing apparatus 1 is taken as the X axis.

  The top beam 31 is formed with a substantially rectangular hollow space 31B in the longitudinal direction along the central axis. The top beam 31 mounts a slider 32 that supports the quill 33 in a state in which the quill 33 passes through the hollow space 31B so that the slider 32 can reciprocate in the front-rear direction. Therefore, when the top beam 31 moves in the left-right direction, the slider 32 and the quill 33 also move in the left-right direction at the same time.

  The slider 32 is reciprocated in a horizontal axis direction corresponding to the front-rear direction of the additive manufacturing apparatus 1 by a servo motor 32A that is a linear motor. In the additive manufacturing apparatus 1 of the embodiment, the control axis in the front-rear direction of the additive manufacturing apparatus 1 is the Y axis. The slider 32 supports the quill 33 so that it can move in the vertical direction.

  The quill 33 is reciprocated in a vertical one-axis direction corresponding to the vertical direction of the additive manufacturing apparatus 1 by a rotary servomotor 33A. In the additive manufacturing apparatus 1 according to the embodiment, the control axis in the vertical direction of the additive manufacturing apparatus 1 is the Z axis. The quill 33 passes through the hollow space 31 </ b> B provided in the top beam 31 and moves in the front-rear direction as the slider 32 moves.

  In the hollow hole 33B of the quill 33 as shown in FIG. 4, a transmission mechanism (not shown) such as a ball screw and a nut that transmits the driving force of the rotary servomotor 33A to move the quill 33 up and down, and a powder supply device 6 powder supply tube 6D, and optical axis tube 8D for guiding the laser beam of laser irradiation device 8 or a light guide line in place of optical axis tube 8D are accommodated.

  The rotor 34 is rotated horizontally around one vertical axis (Z axis) by a direct drive type rotary servo motor 34 provided at the lower end of the quill 33. The rotor 34 can be positioned in the rotational direction by indexing the rotational angle, and selectively rotates clockwise and counterclockwise to rotate the modeling head 2 in the horizontal direction around the Z-axis axis. Let In the additive manufacturing apparatus 1 of the embodiment, the control axis in the horizontal rotation direction of the additive manufacturing apparatus 1 is set as the C axis.

  Each cable (not shown) including the power supply line of the rotary servo motor 34A, the input / output line of the control signal, and the signal output line of the position detector passes through the hollow hole 33B of the quill 33 together with other cable groups. Or drawn around the outer periphery of the quill 33 and led out of the additive manufacturing apparatus 1.

  The table 4 is a means for horizontally placing a modeled object during modeling or a desired article after modeling. As shown in FIG. 2, in the additive manufacturing apparatus 1 according to the embodiment, a base plate 4A is installed on a table in advance. Therefore, the time for forming the first layer of the sintered layer can be eliminated, and the modeling time can be shortened. When the second powder layer is sintered, the base plate 4A is advantageously made of a material that is easily fixed to the first layer on which the second sintered layer is based. The material of the base plate 4A is desirably the same as the metal material powder forming the article.

  The modeling chamber 5 is formed in a space surrounded by four frame plates 5A. The frame 5A is erected on the table 4. Therefore, the modeling room 5 is formed on the table 4. Modeling is performed in the modeling chamber 5, and the frame body 5 </ b> A covers the modeling chamber 5 so that the material powder is not easily scattered outside the modeling chamber 5. In particular, in the additive manufacturing apparatus 1 according to the embodiment, since the sintered layer is formed in a band shape, it is not necessary to partition by the frame body 5A so that the distributed material powder does not go out of the modeling chamber 5, As a result, it is advantageous in that it is not necessary to move the table 4 or the frame 5A in the vertical direction in accordance with the progress of modeling.

  As shown in FIGS. 3 and 4, the powder supply device 6 includes at least a powder storage box 6A, a base 6B, a supply amount adjuster 6C, and a powder supply pipe 6D. The powder supply device 6 includes one or more powder storage tanks (not shown) installed outside the modeling chamber 5 and a powder pumping device. The powder pumping device sucks up a required amount of metal powder from the powder storage tank and generates powder. It sends to the powder storage box 6A through the supply pipe 6D. However, the replenishment of the material powder is performed by an arbitrary method as long as it does not hinder the relative movement of the modeling head 2. For example, the material powder can be replenished to the powder supply box 6A from a bottle enclosing the material powder.

  The powder storage box 6A, the base 6B, and the supply amount adjuster 6C are provided in the modeling head 2 so as to be positioned in front of the blade 7A of the homogenizer 7 and the laser irradiator 8A of the laser irradiator 8, respectively. Therefore, the powder storage box 6A, the base 8B, and the supply amount adjuster 6C move in advance of the blade 7A and the laser irradiator 8A.

  The powder storage box 6A of the powder supply device 6 is formed such that the maximum cross-sectional area at the upper end is sufficiently larger than the opening area of the powder supply port 6E formed by the base 6B, and the base from the upper end toward the lower end. It has a funnel shape that narrows the opening at the lower end communicating with 6B. Therefore, most powder material having a large specific gravity falls freely by its own weight and is supplied from the powder supply port 7E to a predetermined modeling area.

  Even when the size of the powder supply box 6A is limited due to the reason for avoiding interference, the amount of material powder required per unit time is continuously supplied to a predetermined modeling area only by free fall of the material. In the case where it cannot be expected, a pressure higher than the atmospheric pressure is applied to the powder storage box 6A by constantly pressing the material powder by the pressure feeding device. As a result, the material powder stored in the powder storage box 6A is pushed out to the powder supply port 6E, and a sufficient amount of material powder required can be supplied.

  The supply amount adjuster 6C adjusts the amount of material powder supplied per unit time. The supply amount adjuster 6C horizontally moves a slide plate (not shown) having a through-hole having the same area or more as the powder supply port 6E formed by the base 6B in a direction orthogonal to the traveling direction of the modeling head 2. The opening area of the powder supply port 6E can be arbitrarily changed. Therefore, the amount of the material powder that freely falls per unit time can be determined by moving the slide plate and adjusting the degree of opening of the powder supply port 6E. When the modeling is not performed, the powder supply port 6E is closed by the slide plate, and the supply of the material powder is stopped.

  The homogenizer 7 has at least a blade 7A. The blade 7 </ b> A is provided in the housing 2 </ b> A of the modeling head 2 behind the base 6 </ b> B of the powder supply tube 6 and in front of the laser irradiator 8 </ b> A of the laser irradiation device 8 along the traveling direction. One end of the blade 7 </ b> A is provided so as to be almost in contact with the side surface of the fall prevention body 2 </ b> C provided in the modeling head 2.

  The blade 7A can move in the vertical direction. By moving the blade 7A in the vertical direction and adjusting the height position of the blade 7A, the material powder spread in a strip shape by the powder supply device 6 so as to form a powder layer having a predetermined set thickness is obtained. Can be leveled.

  The laser irradiation device 8 irradiates a predetermined irradiation spot 8E as shown in FIG. 3 with a laser beam such as a YAG laser or a carbon dioxide laser, and the metal material powder of the powder layer PL at the predetermined irradiation spot 8E. The body is sintered and solidified. The laser irradiation device 8 guides the optical energy of the laser light output from the high-power laser oscillator to the laser irradiator 8A by a plurality of reflectors, a light guide plate, and an optical fiber cable. The laser irradiation device 8 scans the laser beam to follow the formation of the powder layer, and irradiates the laser beam to a predetermined irradiation spot 8E on the powder layer.

  The laser irradiator 8A incorporates a sighting machine (not shown) including a plurality of condensing lenses that are relatively movable in the vertical direction. The laser irradiation device 8 guides the laser beam output from the laser oscillator to the laser irradiator 8A. In the laser irradiator 8A, the sighting is performed by the sighting device so that the amount of energy is constant at the irradiation diameter d of the predetermined irradiation spot 8E, and the laser beam is irradiated.

  The laser irradiator 8A includes a material supply box 6A and a base 6B that forms a powder supply port 6E of the powder supply device 6 along the traveling direction, and a housing 2A of the modeling head 2 behind the blade 7A of the homogenization device 7. It is provided so as to be integrated, and moves so as to track the powder supply port 6E.

  Since the laser irradiator 8A always moves so as to follow the movement locus of the powder supply port 6E and the blade 7A, the belt-like sintered layer can be formed while forming the powder layer PL. Therefore, according to the additive manufacturing apparatus 1 of the embodiment, the material powder to be distributed can be reduced. Further, the material powder is distributed and the powder layer and the sintered layer are continuously formed, whereby the material powder is distributed over the entire area of the modeling chamber 5 to form a powder layer, and the sintered layer is formed in a predetermined modeling area. Compared with the method of forming, the work efficiency is not lowered so much.

  The additive manufacturing apparatus according to the embodiment irradiates a laser beam along a traveling direction in which the powder layer is solidified, and repeatedly reciprocates a laser beam or an electron beam within a predetermined distance in a direction orthogonal to the traveling direction. By moving and irradiating, a band-like sintered layer or melt-solidified layer having a desired width can be formed.

  Specifically, in the layered manufacturing apparatus 1 of the embodiment shown in FIG. 2, as shown in FIGS. 4 and 5, the laser irradiator 8A is formed of the modeling head 2 by a small electric actuator 8F such as a linear motor. It reciprocates within a range of a predetermined distance L along a direction V (hereinafter simply referred to as an orthogonal direction) perpendicular to the traveling direction F of the modeling head 2 along the long hole 2B provided in the housing 2A. be able to.

  Therefore, for example, by moving the modeling head 2 in the traveling direction F and moving the laser irradiation device 8A in the orthogonal direction V, the laser beam is irradiated continuously, linearly, intermittently, or in a point manner. Modeling can be performed while adjusting the width of the sintered layer SL formed in a band shape with respect to PL within a predetermined distance L. As a result, according to the additive manufacturing apparatus 1 of the embodiment, work efficiency can be further improved.

  The operation of the additive manufacturing apparatus 1 according to the embodiment for generating a metal desired article by the additive manufacturing method of the present invention will be described below with reference to FIGS. 2 to 11 as appropriate. However, in the additive manufacturing apparatus 1 of the embodiment, in order to shorten the modeling time, the base plate 4A is previously set horizontally on the table to perform modeling.

  Prior to modeling, the relative movement trajectory of the modeling head 2 is set in advance in a control device (not shown). Specifically, first, three-dimensional shape data is obtained for each layer divided into a plurality of layers with a set thickness t from solid data of a desired article created by CAD. And the data of the planar shape (contour shape) OL of the modeling object in the middle of modeling in each layer is obtained from the three-dimensional shape data for each layer.

  Next, the relative movement locus of the modeling head 2 along the plane shape OL as shown in FIG. 5 from the data of the plane shape OL for each layer and the irradiation diameter d of a predetermined irradiation spot 8E of the laser beam. Is generated. The generated relative movement trajectory and a basic relative movement trajectory BL defined in advance are connected to generate data of the relative movement trajectory of the modeling head 2 for each layer. Then, the movement speed data and movement direction data of the modeling head 2 are added to each layer to generate movement control data (movement program) of the modeling head 2.

  The basic relative movement trajectory BL in the additive manufacturing apparatus 1 of the embodiment is preliminarily formed in a comb-teeth shape that moves vertically and horizontally on a horizontal plane with a width determined by the irradiation diameter d of a predetermined irradiation spot 8E of laser light. Is defined. However, as shown in FIG. 11, in the case where the laser irradiator 8A is repeatedly reciprocated within a predetermined distance L in the orthogonal direction V while moving the modeling head 2 in the traveling direction F, a predetermined irradiation spot 8E is used. Instead of the irradiation diameter d, a comb-shaped basic relative movement locus BL is determined by a predetermined distance L.

  When the laser irradiator 8A is reciprocated within the range of the predetermined distance L in the orthogonal direction V, the modeling head 2 is moved in the traveling direction F every time the laser irradiator 8A moves in the orthogonal direction V by the predetermined distance L. When operating so as to move by a predetermined unit moving distance k, the scanning trajectory of the laser light becomes a rectangle as shown in the lower left of FIG. Further, while moving the modeling head 2 in the traveling direction F at a predetermined moving speed, at the same time, the laser irradiator 8A is reciprocated within a predetermined distance L in the orthogonal direction V at a predetermined “swinging speed”. When operated, the scanning trajectory of the laser light has a sawtooth shape as shown in the lower right of FIG.

  At the time of modeling, as shown in FIG. 5, the movement control data of the modeling head 2 that has already been generated in the nth layer among the layers obtained by dividing the desired article into a plurality of layers. Then, the modeling head 2 is moved to the starting point SP, and is moved from the starting point SP along the planar shape OL at a predetermined moving speed.

  While the modeling head 2 is moving at a predetermined moving speed, the metal material powder is supplied from the powder storage box 6A of the powder supply device 6 to the powder supply port 6E with a predetermined supply amount, It distributes to a predetermined modeling area | region from the powder supply port 6E. Immediately after that, as shown in FIG. 6 to FIG. 8, the material powder spread by causing the blade 7A of the flattening device 7 to follow the material powder is uniformly stripped to a height according to the set thickness t. The powder layer PL is formed.

  After forming the powder layer PL, the powder layer PL is sintered with a predetermined width by the laser irradiator 8A following the powder storage box 6A and the blade 7A to form a belt-like sintered layer SL. As shown in FIG. 11, the width of the sintered layer SL is the irradiation diameter d of a predetermined irradiation spot 8B, or substantially the same as the length obtained by adding the irradiation diameter d from a predetermined distance L. The modeling head 2 moves on the basic relative movement trajectory BL having a comb-tooth shape from a point that makes a round of the modeling region for each layer in accordance with the planar shape OL, and finishes the modeling in the nth layer at the end point EP.

  When the planar shape OL of the modeled object in the middle of modeling is a straight line, the fall prevention body 2C is in close contact with the linear edge as shown in FIG. 9, and the set thickness t as shown in FIG. 6 and FIG. It protrudes downward to a slightly larger extent. When the planar shape OL is a curved line, the fall prevention body 2C is deformed in accordance with the curved surface as shown in FIG. 10 and comes into close contact with the curved edge, and the set thickness t as shown in FIGS. It protrudes downward to a slightly larger extent. Therefore, while the modeling head 2 is moving along the edge of the modeled object in the middle of the modeling along the planar shape OL, the fall prevention body 2C suppresses the fall of the material powder, and the height of the powder layer PL is maintained. It is.

  In the case where the edge is a corner, the length of contact between the fall prevention body 2C and the edge in the straight line before and after the modeling head 2 changes direction is extremely small. However, since the irradiation diameter d of the predetermined irradiation spot 8E of the laser beam is sufficiently small, in other words, the width of the band-shaped powder layer formed of the material powder to be distributed is not so large, By being in a state of biting into the fall prevention body 2C, the fall of the material powder is substantially suppressed to the minimum.

  Assuming that the set thickness t of the powder layer PL is in the range of about 30 μm to 100 μm, the protrusion amount h required for the fall prevention body 2C is at most about 200 μm. Accordingly, if the fall prevention body 2C can be deformed so as to be restored in the vertical direction within the range of 0.2 mm to 1.0 mm, and if the surface is formed of a smooth material, the modeling head 2 can be When the upper surface is moved, as shown in FIG. 8, the fall prevention body 2 </ b> C does not become an obstacle to the running of the modeling head 2 by being deformed so that the protruding portion is crushed upward. The modeling head 2 can be moved without damaging the already formed sintered layer SL.

  When the forming head 2 moves along the basic relative movement trajectory to form the band-like sintered layer, it is formed along the basic relative movement trajectory with the sintered layer formed along the planar shape OL. To obtain a sintered layer of a predetermined modeling region that is defined by being surrounded by a predetermined planar shape OL for each layer. Can do. And a desired article can be obtained by laminating a sintered layer of a predetermined modeling area in each layer.

  The additive manufacturing method and additive manufacturing apparatus of the embodiment described above are not limited to the specifically shown embodiments, and some examples have already been shown. Various applications are possible without departing from the technical idea. Note that the specific additive manufacturing apparatus shown in the embodiment is an additive manufacturing apparatus including a laser irradiation apparatus, but an electron beam is prepared by preparing a work environment necessary for electron beam irradiation under the same technical idea. It can replace and apply to the additive manufacturing apparatus which comprises an irradiation apparatus.

  The present invention can be applied to the production of a metal article having an arbitrary three-dimensional shape by an additive manufacturing method in which a metal material powder is solidified and laminated. For example, the present invention can be used for manufacturing metal parts such as molds or gears. The present invention contributes to the development of the technical field of producing metal articles by modeling.

DESCRIPTION OF SYMBOLS 1 Layered modeling apparatus 2 Modeling head 2A Housing | casing 2B Long hole 2C Fall prevention body 3 Moving apparatus 4 Table 5 Modeling room 5A Frame body 6 Powder supply apparatus 6A Powder storage box 6B Base 6C Supply amount regulator 6D Powder supply pipe 6E Powder supply Mouth 7 Uniformizer 7A Blade 8 Laser irradiation device 8A Laser irradiator 8B Laser oscillator 8C Scanning device 8D Optical axis tube 8E Irradiation spot 8F Electric actuator

Claims (6)

  The material powder is spread in a strip shape for each layer obtained by dividing the desired article into a plurality of layers, and the material powder spread in the strip shape has a predetermined height according to a predetermined thickness for each layer. The powder layer is made to follow the distribution of the material powder, and the powder layer is solidified to form a band-like sintered layer or a melt-solidified layer, and the band-like sintered layer or the melt-solidified for each layer The layers are combined to obtain a sintered layer or a melt-solidified layer in a predetermined modeling area, and a desired article is obtained by laminating the sintered layers or the melt-solidified layers in the predetermined modeling area of the respective layers. Additive manufacturing method.   Forming the band-like sintered layer or melt-solidified layer while irradiating the laser beam or electron beam repeatedly and reciprocatingly within a predetermined distance in a direction perpendicular to the advancing direction of solidifying the powder layer. The additive manufacturing method according to claim 1.   A powder supply device that distributes a material powder in a strip shape for each layer obtained by dividing a desired article into a plurality of layers, and a material powder that is distributed in a strip shape following the powder supply device is set in each layer A homogenizer that forms a belt-like powder layer that is leveled to a predetermined height according to the thickness, and forms a belt-like sintered layer by sintering the powder layer that has been flattened into a belt-like shape following the homogenizer. And a laser beam irradiating device.   The powder storage box of the powder supply device, the blade of the homogenizing device, and the laser irradiator of the laser irradiation device are integrally attached, and the horizontal one axis direction is orthogonal to the horizontal one axis direction. The horizontal one axis direction and the vertical one axis direction orthogonal to each horizontal one axis direction move relative to each other synchronously, and the rotation angle can be indexed around the vertical one axis in synchronization with each axis direction. The additive manufacturing apparatus according to claim 3, comprising a rotating modeling head.   The additive manufacturing apparatus according to claim 4, wherein the laser irradiator reciprocates within a predetermined distance in a direction orthogonal to the traveling direction.   5. The additive manufacturing according to claim 4, wherein the modeling head includes a fall prevention body that is in close contact with the edge so that the material powder supplied from the powder supply device does not fall freely from an edge of a modeled object during modeling. apparatus.

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