Patent Description:
In the related art, a method described in <CIT> is disclosed as a manufacturing method of simply forming a three-dimensional shape using a metal material. The three-dimensional fabricated object manufacturing method disclosed in <CIT> is used to form a metal paste, which includes metal powder, a solvent, and an adhesion enhancer in a raw material, in material layers of a layered state. Then, metal sintered layers or metal melted layers are formed by radiating a light beam to material layers in the layered state and the sintered layers or the melted layers are stacked by repeating the forming of the material layers and the radiation of the light beam, so that a desired three-dimensional fabricated object can be obtained.

A three-dimensional fabricated object is suggested to be formed by supplying a metal powder using a powder metal buildup nozzle capable of building up a (three-dimensional) form, as disclosed in <CIT>, or a powder supply nozzle capable of performing buildup and welding, as disclosed in <CIT>, and by melting and solidifying the supplied metal powder with a laser.

A three-dimensional fabricated object can be formed by forming and stacking sintered layers to material layers, as in a method disclosed in <CIT>, or a three-dimensional fabricated object can be formed by repeating buildup, as in methods disclosed in <CIT> and <CIT>. These methods are methods of forming one single layer which forms a three-dimensional fabricated object and stacking the single layers. In a case in which the single layer of one configuration in a three-dimensional fabricated object is formed, laser radiation is scanned to draw a trajectory so that a formed sintered portion is filled in the case of <CIT> and a nozzle is moved along a trajectory drawn so that the shape of a sintered portion is filled in the cases of <CIT> and <CIT>. That is, to draw the above-described trajectory by relatively moving a table for forming the three-dimensional fabricated object and a laser radiation device or the nozzle, a device driving unit necessarily performs minute control for the relative movement.

A time taken to form the above-described single layer increases as the length of the trajectory is longer, that is, the area of the sintered portion is greater. Accordingly, to improve productivity, a scanning speed of the laser radiation or a movement speed of the nozzle is necessarily increased. However, when an output of the laser is not high, there is a concern of a sintering fault or a melting fault occurring.

<CIT> discloses additive manufacturing processes that utilize multiple build heads. In one embodiment, an additive manufacturing apparatus includes a plurality of build heads each adapted to cause the formation of a structure onto a surface, a substrate, and a translation system. The translation system is associated with at least one of the plurality of build heads and the substrate, such that the spatial relationship between the plurality of build heads and the substrate can be controlled.

<CIT> discloses a method for additive manufacturing with multiple materials. First, second, and third adjacent powder layers are delivered onto a working surface in respective first, second, and third area shapes of adjacent final materials in a given section plane of a component. The first powder may be a structural metal delivered in the sectional shape of an airfoil substrate. The second powder may be a bond coat material delivered in a sectional shape of a bond coat on the substrate. The third powder may be a thermal barrier ceramic delivered in a section shape of the thermal barrier coating. A particular laser intensity is applied to each layer to melt or to sinter the layer. Integrated interfaces may be formed between adjacent layers by gradient material overlap and/or interleaving projections.

<CIT> discloses a method for fixing a functional material, comprising a droplet ejection step of ejecting a droplet of a functional material dispersed in a solvent onto a fixing surface, and a drying step of locally heating the droplet ejected on the fixing surface and gasifying part of the droplet by irradiating the droplet with a laser beam.

<CIT>, <CIT> and <CIT> are also relevant.

An advantage of some aspects of the invention is that it provides a three-dimensional forming apparatus with high productivity by driving a plurality of energy supply units synchronously with a simple configuration.

A three-dimensional forming apparatus according to an aspect of the invention is defined in claim <NUM>.

A sintered portion corresponding to one energy radiation unit is formed along one path of the relative movement of the head base relative to the stage by energy radiated from the energy radiation unit included in one head unit. Accordingly, the three-dimensional forming apparatus according to this aspect includes the plurality of head units in the head base, and thus a plurality of sintered portions can be formed along one path of the head base. Accordingly, it is possible to shorten a relative movement path length between the head base and the stage along which a desired sintered region is formed, and thus it is possible to obtain the three-dimensional forming apparatus with high productivity.

A three-dimensional forming apparatus according to a second aspect of the invention is defined in claim <NUM>.

A sintered portion corresponding to one head unit is formed along one path of the relative movement of the head base relative to the stage by energy radiated from the energy radiation unit to the sintered material supplied from the material ejection unit included in one head unit. Accordingly, the three-dimensional forming apparatus according to this aspect includes the plurality of head units in the head base, and thus a plurality of sintered portions can be formed along one path of the head base. Accordingly, it is possible to shorten a relative movement path length between the head base and the stage along which a desired sintered region is formed, and thus it is possible to obtain the three-dimensional forming apparatus with high productivity.

In the three-dimensional forming apparatus according to this aspect, the amount of sintered material necessary in a region in which the shape of a three-dimensional fabricated object to be formed is formed is supplied and the energy is supplied from the energy radiation unit to the supplied sintered material. Therefore, a loss of the supplied material and a loss of the supplied energy are reduced.

Preferably, of the plurality of material supply units, the material supply unit including the material ejection unit held in at least one of the head units may accommodate different sintered material from the other material supply units.

Accordingly, the material supply unit supplying the sintered material for each different composition can be included. Thus, the material can be supplied from each material supply unit of each composition, and thus different materials can be sintered or melted by the energy radiation units. Thus, it is possible to easily form the fabricated object formed of the materials of two or more kinds of compositions.

Accordingly, the radiation of the energy can be focused on a supply material which is a target, and thus a three-dimensional fabricated object with good quality can be formed. For example, a radiated energy amount (power or a scanning speed) can be easily controlled according to a kind of sintered material, and thus the three-dimensional fabricated object with desired quality can be obtained.

A three-dimensional forming method according to a third aspect of the invention is defined in claim <NUM>.

A sintered portion corresponding to one energy radiation unit is formed along one path of the relative movement of the head base relative to the stage by energy radiated from the energy radiation unit included in one head unit. Accordingly, in the three-dimensional forming method according to this aspect, the three-dimensional forming apparatus including the plurality of head units in the head base is used, and thus a plurality of sintered portions can be formed along one path of the head base. Accordingly, it is possible to shorten a relative movement path length between the head base and the stage along which a desired sintered region is formed, and thus it is possible to obtain the three-dimensional forming method with high productivity.

In this aspect, the "first single layer" and the "second layer" do not mean the first and second layers of stacked single layers. A single layer in the lower portion of the stack of repeatedly stacked single layers is referred to as the "first single layer" and a single layer stacked on the first single layer is referred to as the "second layer".

A three-dimensional forming method according to a fourth aspect of the invention is defined in claim <NUM>.

A sintered portion corresponding to one head unit is formed along one path of the relative movement of the head base relative to the stage by energy radiated from the energy radiation unit to the sintered material supplied from the material ejection unit included in one head unit. Accordingly, in the three-dimensional forming method according to this aspect, the three-dimensional forming apparatus including the plurality of head units in the head base can be used, and thus a plurality of sintered portions can be formed along one path of the head base. Accordingly, it is possible to shorten a relative movement path length between the head base and the stage along which a desired sintered region is formed, and thus it is possible to obtain the three-dimensional forming method with high productivity.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, wherein like numbers reference like elements.

Hereinafter, embodiments of the invention will be described with reference to the drawings.

<FIG> is a schematic diagram illustrating the configuration of a three-dimensional forming apparatus according to a first embodiment. In the present specification, "three-dimensional forming" refers to forming a so-called stereoscopically fabricated object and includes, for example, forming a shape having a thickness even when the shape is a flat shape or a so-called two-dimensional shape.

A three-dimensional forming apparatus <NUM> (hereinafter referred to as a forming apparatus <NUM>) illustrated in <FIG> includes a sintering device <NUM> that forms a three-dimensional fabricated object and a material supply device <NUM> serving as a material supply unit that supplies the sintering device <NUM> with supply material <NUM> (hereinafter referred to as a green sheet <NUM>) called a so-called green sheet in which metal powder and a binder which are raw material of the three-dimensional fabricated object are kneaded and formed to a sheet shape.

The material supply device <NUM> includes a supply base <NUM>, a supply table <NUM> that can be driven in the Z axis direction oriented in the illustrated gravity direction by a driving unit (not illustrated) included in the supply base <NUM>, and a transfer device <NUM> that holds one topmost stacked green sheet among a plurality of green sheets <NUM> placed on the supply table <NUM> and transfers the green sheet to the sintering device <NUM>.

The transfer device <NUM> includes a sheet holding unit 230a that is capable of holding the green sheet <NUM> and a supply driving unit 230b that moves the sheet holding unit 230a to the supply table <NUM> relatively in at least the X axis direction and the Y axis direction. The sheet holding unit 230a includes a sheet adsorption unit 230c serving as, for example, a unit capable of holding and detaching the green sheet <NUM> in depressurization and sucking manners, and thus the green sheet <NUM> can be adsorbed and held by the sheet adsorption unit 230c. The method of holding the green sheet <NUM> by the sheet adsorption unit 230c is not limited to the above-described method. For example, when a raw material metal is a magnetic material, the green sheet may be mechanically held using a magnetic-force adsorption method or the like or pilot holes.

The sintering device <NUM> includes a base <NUM>, a stage <NUM> that can be moved in the illustrated X, Y, or Z direction or can be driven in a rotational direction about the Z axis by a driving device <NUM> serving as a driving unit included in the base <NUM>, and a head base supporting unit <NUM> that has one end portion fixed to the base <NUM> and the other end portion holding and fixing a head base <NUM> in which a plurality of energy radiation units <NUM> are held. In the embodiment, a configuration in which the stage <NUM> is driven in the X, Y, or Z direction by the driving device <NUM> will be described. However, the invention is not limited thereto. The stage <NUM> and the head base <NUM> may be able to be driven relatively in the X, Y, or Z direction.

The sintering device <NUM> includes, on the stage <NUM>, a sample plate <NUM> that has heat resistance property to protect the stage <NUM> against heat energy radiated from an energy radiation unit to be described below. The green sheets <NUM> transferred from the material supply device <NUM> are stacked to be disposed on the sample plate <NUM>. The sintering device <NUM> may include a press roller <NUM> that is driven to reciprocate in the X axis direction, in this example, while pressing the green sheet <NUM> of the topmost layer to closely adhere the green sheet <NUM> of an immediately below layer against the green sheet <NUM> transferred and stacked in the topmost layer. The press roller <NUM> preferably includes a unit that heats the green sheet <NUM> in order to improve the adhesion between the upper and lower green sheets <NUM>.

The plurality of energy radiation units <NUM> held in the head base <NUM> will be described as the energy radiation units <NUM> that radiate lasers as energy in the embodiment (hereinafter the energy radiation units <NUM> are referred to as laser radiation units <NUM>). By using a laser as energy to be radiated, the radiation of the energy can be focused on a supply material which is a target, and thus a three-dimensional fabricated object with good quality can be formed. For example, a radiated energy amount (power or a scanning speed) can be easily controlled according to a kind of sintered material, and thus the three-dimensional fabricated object with desired quality can be obtained.

The forming apparatus <NUM> includes a control unit <NUM> serving as a control unit that controls the stage <NUM>, the supply table <NUM>, the laser radiation unit <NUM>, and the transfer device <NUM> described above based on fabrication data of the three-dimensional fabricated object output from, for example, a data output apparatus such as a personal computer (not illustrated). The control unit <NUM> includes a driving control unit of the stage <NUM>, a driving control unit of the supply table <NUM>, a driving control unit of the laser radiation unit <NUM>, and a driving control unit of the transfer device <NUM> and includes a control unit that controls the driving control units such that these units are driven together, although not illustrated.

Signals for controlling movement start and stop, a movement direction, a movement amount, and a movement speed of the stage <NUM> or the supply table <NUM> are generated in a stage controller <NUM> based on control signals from the control unit <NUM> by the driving device <NUM> included in the base <NUM>. Thus, control signals for moving the stage <NUM> included to be movable with respect to the base <NUM> and the supply table <NUM> included to be movable with respect to the supply base <NUM> are sent to the driving device <NUM> included in the base <NUM> or a driving device (not illustrated) included in the supply base <NUM> to be driven.

Signals for controlling movement of the sheet holding unit 230a and the supply driving unit 230b included in the transfer device <NUM> and the holding or detachment of the green sheet <NUM> to or from the sheet adsorption unit 230c are generated in a material supply device controller <NUM> based on control signals from the control unit 400Thus the transfer to the sintering device <NUM> of the green sheets <NUM> by the transfer device <NUM> included in the material supply device <NUM> is controlled.

In regard to the laser radiation unit <NUM> held in the head base <NUM>, control signals are sent from the control unit <NUM> to a laser controller <NUM> and output signals for causing one or all of the plurality of laser radiation units <NUM> to radiate lasers are sent from the laser controller <NUM>. The radiation of the lasers from the laser radiation units <NUM> is controlled such that the lasers are radiated to sinter-formed regions obtained from shape data of a predetermined three-dimensional fabricated object in the green sheets <NUM> placed on the stage <NUM> in synchronization with driving signals of the stage <NUM> by the stage controller <NUM>.

<FIG> are diagrams illustrating an example of a holding form of the laser radiation units <NUM> included in a plurality of head units <NUM> held in the head base <NUM>. <FIG> is an external diagram illustrating the head base <NUM> in a direction indicated by an arrow A illustrated in <FIG>. <FIG> is a schematic sectional view taken along the line B-B' illustrated in <FIG>.

As illustrated in <FIG>, the plurality of head units <NUM> are held in the head base <NUM> included in the forming apparatus <NUM> according to the first embodiment. As illustrated in <FIG>, the head unit <NUM> includes the laser radiation unit <NUM> and a holding tool 160a that holds the laser radiation unit <NUM> so that a laser outlet 140a from which a laser L of the laser radiation unit <NUM> exits is disposed toward the green sheet <NUM> in the head base <NUM>. The head unit <NUM> is fixed to the head base <NUM> by a fastening unit (not illustrated) which can be detachably mounted.

According to the invention, six sets of head units <NUM> are fastened to the head base <NUM>. As illustrated in <FIG>, first head units <NUM> and <NUM>, second head units <NUM> and <NUM>, and third head units <NUM> and <NUM> in one line of two sets are disposed in three lines from the lower side of the drawing. As illustrated in <FIG>, sintered portions <NUM> with a sintering width r are formed in the green sheet <NUM> by the lasers L radiated from the laser radiation units <NUM>, so that a part of the configuration of a three-dimensional fabricated object is formed as an aggregate of the sintered portions <NUM> formed by the lasers L radiated from the laser radiation units <NUM> included in the plurality of head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> held in the head base <NUM>.

<FIG> are plan views (in the direction indicated by the arrow A illustrated in <FIG>) conceptually illustrating a relation between disposition of the head units <NUM> and form shapes of the sintered portions <NUM>. First, as illustrated in <FIG>, the lasers L are radiated from the laser radiation units <NUM> of the head units <NUM> and <NUM> at a sintering start point p1 of the green sheet <NUM>, so that sintered portions 310a and 310b are formed. To facilitate the description, the sintered portions <NUM> are hatched even in the plan views.

While the lasers L are radiated from the head units <NUM> and <NUM>, the green sheet <NUM> is moved in the Y (+) direction relative to the head base <NUM> up to a position at which the sintering start point p1 illustrated in <FIG> corresponds to the second head units <NUM> and <NUM>. Accordingly, the sintered portions 310a and 310b extend from the sintering start point p1 to a position p2 after the relative movement of the green sheet <NUM> so that the sintering width r is maintained. Further, the lasers L are radiated from the second head units <NUM> and <NUM> corresponding to the sintering start point p1, so that sintered portions 310c and 310d are formed.

The lasers L are radiated at the position at which the sintering start point p1 illustrated in <FIG> corresponds to the second head units <NUM> and <NUM>, so that the sintered portions 310c and 310d start to be formed. While the lasers L are radiated from the head units <NUM> and <NUM>, the green sheet <NUM> is moved up to a position at which the sintering start point p1 illustrated in <FIG> corresponds to the third head units <NUM> and <NUM> relative to the head base <NUM>. Accordingly, the sintered portions 310c and 310d extend from the sintering start point p1 to the position p2 after the relative movement of the green sheet <NUM> so that the sintering width r is maintained. Simultaneously, the sintered portions 310a and 310b extend from the sintering start point p1 to a position p3 after the relative movement of the green sheet <NUM> so that the sintering width r is maintained. Further, the lasers L are radiated from the third head units <NUM> and <NUM> corresponding to the sintering start point p1, so that sintered portions 310e and 310f are formed.

The lasers L are radiated at the position at which the sintering start point p1 illustrated in <FIG> corresponds to the third head units <NUM> and <NUM>, so that the sintered portions 310e and 310f start to be formed. While the lasers L are radiated from the head units <NUM> and <NUM>, the green sheet <NUM> is moved relative to the head base <NUM> so that the sintering start point p1 illustrated in <FIG> is further moved in the Y (+) direction. Accordingly, the sintered portions 310e and 310f extend from the sintering start point p1 to the position p2 after the relative movement of the green sheet <NUM> so that the sintering width r is maintained. Simultaneously, the sintered portions 310a and 310b extend from the sintering start point p1 to a position p4 after the relative movement of the green sheet <NUM> and the sintered portions 310c and 310d extend from the sintering start point p1 to the position p3 after the relative movement so that the sintering width r is maintained.

In a case in which the position p4 is set to a sintering end position (hereinafter the position p4 is referred to as the sintering end point p4), the radiation of the lasers L from the head units <NUM> and <NUM> is stopped at the sintering end point p4 illustrated in <FIG>. Further, while the green sheet <NUM> is moved relatively in the Y(+) direction, the lasers L are radiated until the head units <NUM>, <NUM>, <NUM>, and <NUM> reach the sintering end point p4. As illustrated in <FIG>, the sintered portions 310c, 310d, 310e, and 310f are formed from the sintering start point p1 to the sintering end point p4 so that the sintering width r is maintained. In this way, by radiating the lasers L sequentially from the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> while moving the green sheet <NUM> from the sintering start point p1 to the sintering end point p4, it is possible to form the substantially rectangular sintered portions <NUM> with a width R and a length H in the example of the embodiment.

As described above, the sintering device <NUM> included in the forming apparatus <NUM> according to the invention can form the sintered portions <NUM> with a desired shape in the green sheet <NUM> by selectively radiating the lasers L from the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> in synchronization with the movement of the green sheet <NUM>. As described above, by merely moving the green sheet <NUM> in one direction of the Y axis direction in the embodiment, it is possible to obtain the sintered portions <NUM> with a desired shape in a region with a width R × a length H illustrated in <FIG>. Thus, it is possible to obtain a partial fabricated object to be described below as an aggregate of the sintered portions <NUM>.

The forming apparatus <NUM> in which the green sheet <NUM> is supplied from the material supply device <NUM> to the sintering device <NUM> has been described, but the invention is not limited thereto. For example, a material before sintering may be supplied by supplying powder metal onto the sample plate <NUM> and forming the powder metal with a desired thickness by a squeegee.

<FIG> are schematic diagram illustrating the configuration of a three-dimensional forming apparatus according to a second embodiment. A three-dimensional forming apparatus <NUM> (hereinafter referred to as a forming apparatus <NUM>) illustrated in <FIG> is different from the forming apparatus <NUM> according to the first embodiment in the configuration of a material supply unit and the configuration of a head base and head units. Accordingly, the same reference numerals are given to the same constituent elements as those of the forming apparatus <NUM> according to the first embodiment and the description thereof will be omitted.

As illustrated in <FIG>, the forming apparatus <NUM> includes a base <NUM>, a stage <NUM> that can be moved in the illustrated X, Y, or Z direction or can be driven in a rotational direction about the Z axis by a driving device <NUM> serving as a driving unit included in the base <NUM>, and a head base supporting unit <NUM> that has one end portion fixed to the base <NUM> and the other end portion holding and fixing a head base <NUM> in which a plurality of head units <NUM> including an energy radiation unit <NUM> and a material ejection unit <NUM> are held.

In a process of forming a three-dimensional fabricated object <NUM>, partial fabricated objects <NUM>, <NUM>, and <NUM> are formed on the stage <NUM> in a layered state. In the forming of the three-dimensional fabricated objects <NUM>, as will be described below, the sample plate <NUM> that has heat resistance property may be used to protect against heat of the stage <NUM> so that the three-dimensional fabricated objects <NUM> are formed on the sample plate <NUM>, since the heat energy is radiated from the laser. For example, a ceramic plate can be used as the sample plate <NUM> to obtain the high heat resistance property, and further reactivity with a sintered or melted supply material is low and the three-dimensional fabricated objects <NUM> can be prevented from degrading. In <FIG>, to facilitate the description, three layers of the partial fabricated objects <NUM>, <NUM>, and <NUM> have been exemplified, but partial fabricated objects are stacked until the desired shapes of the three-dimensional fabricated objects <NUM> are obtained.

<FIG> is an enlarged view of a portion C indicating the head base <NUM> illustrated in <FIG>.

As illustrated in <FIG>, the head base <NUM> holds a plurality of head units <NUM>. As will be described below in detail, one head unit <NUM> is configured such that a material ejection unit <NUM> included in the material supply device <NUM> serving as a material supply unit and an energy radiation unit <NUM> serving as an energy radiation unit are held in a holding tool 1400a. The material ejection unit <NUM> includes an ejection nozzle 1230a and an ejection driving unit 1230b that is caused to eject a material from the ejection nozzle 1230a by a material supply controller <NUM>.

The energy radiation unit <NUM> will be described as the energy radiation unit <NUM> radiating a laser as energy in the embodiment (hereinafter the energy radiation unit <NUM> is referred to as a laser radiation unit <NUM>). The radiation of the energy can be focused on a supply material which is a target, and thus a three-dimensional fabricated object with good quality can be formed. For example, a radiated energy amount (power or a scanning speed) can be easily controlled according to a kind of sintered material, and thus the three-dimensional fabricated object with desired quality can be obtained.

The material ejection unit <NUM> is connected to a supply tube <NUM> and the material supply unit <NUM> accommodating the supply material corresponding to each head unit <NUM> held in the head base <NUM>. A predetermined material is supplied from the material supply unit <NUM> to the material ejection units <NUM>. In the material supply unit <NUM>, material accommodation units 1210a accommodate sintered materials including the raw materials of the three-dimensional fabricated objects <NUM> fabricated by the forming apparatus <NUM> according to the embodiment as supply materials. The individual material accommodation units 1210a are preferably connected to the individual material ejection units <NUM> by the supply tubes <NUM>. In this way, since the individual material accommodation units 1210a are provided, a plurality of different kinds of sintered materials can be supplied from the head base <NUM>.

The sintered material which is the supply material is a mixed material of a slurry state (or a paste form) obtained by kneading, for example, an elementary powder of metals such as magnesium (Mg), iron (Fe), cobalt (Co), chrome (Cr), aluminum (AL), titanium (Ti), and a nickel (Ni) which are raw materials of the three-dimensional fabricated object <NUM>, or a mixed powder of an alloy including one or more of the metals with a solvent and a thickener serving as a binder.

As illustrated in <FIG>, the forming apparatus <NUM> includes the control unit <NUM> serving as a control unit controlling the above-described stage <NUM>, the material ejection units <NUM> included in the material supply device <NUM>, and the laser radiation units <NUM> based on fabrication data of the three-dimensional fabricated objects <NUM> output from, for example, a data output apparatus such as a personal computer (not illustrated). Although not illustrated in the drawing, the control unit <NUM> includes at least a driving control unit of the stage <NUM>, an operation control unit of the material ejection unit <NUM>, and an operation control unit of the laser radiation device <NUM>. The control unit <NUM> further includes a control unit that drives and operates the stage <NUM>, the material ejection unit <NUM>, and the laser radiation unit <NUM> together.

For the stage <NUM> included to be movable to the base <NUM>, signals for controlling movement start or stop and a movement direction, a movement amount, a movement speed, or the like of the stage <NUM> are generated in the stage controller <NUM> based on a control signal from the control unit <NUM> and are sent to the driving device <NUM> included in the base <NUM>, so that the stage <NUM> is moved in the illustrated X, Y, or Z direction. For the material ejection unit <NUM> included in the head unit <NUM>, a signal for controlling a material ejection amount or the like from the ejection nozzle 1230a in the ejection driving unit 1230b included in the material ejection unit <NUM> is generated in a material supply controller <NUM> based on a control signal from the control unit <NUM> and a predetermined amount of material is ejected from the ejection nozzle 1230a by the generated signal.

<FIG> and <FIG> illustrate an example of the holding form of the plurality of head units <NUM> held in the head base <NUM> and the laser radiation units <NUM> and the material ejection units <NUM> held in the head units <NUM>. <FIG> is an external diagram illustrating the head base <NUM> in a direction indicated by an arrow D illustrated in <FIG>. <FIG> is a schematic sectional view taken along the line E-E' illustrated in <FIG>.

As illustrated in <FIG>, the plurality of head units <NUM> are held by fixing units (not illustrated) in the head base <NUM>. The head base <NUM> of the forming apparatus <NUM> according to the embodiment include the head units <NUM> of eight units, such as first head units <NUM> and <NUM>, second head units <NUM> and <NUM>, third head units <NUM> and <NUM>, and fourth head units <NUM> and <NUM>, from the lower side of the drawing. Although not illustrated, the material ejection unit <NUM> included in each of the head units <NUM> to <NUM> is linked to the material supply unit <NUM> via the ejection driving unit 1230b by the supply tube <NUM> and the laser radiation unit <NUM> is linked to the laser controller <NUM> to be held in the holding tool 1400a.

As illustrated in <FIG>, the material ejection units <NUM> eject sintered materials M (hereinafter referred to as materials M) toward the sample plate <NUM> placed on the stage <NUM> from the ejection nozzle 1230a. In the head unit <NUM>, an ejection type in which the material M is ejected in a liquid droplet form is exemplified. In the head unit <NUM>, an ejection type in which the material M is supplied in a continuous form is exemplified. The ejection type of the material M may be either the liquid droplet form or the continuous form. In the embodiment, the material M is assumed to be ejected in the liquid droplet form in the embodiment.

The material M ejected in the liquid droplet form from the ejection nozzle 1230a flies substantially in the gravity direction to be landed on the sample plate <NUM>. The laser radiation units <NUM> are held in the holding tools 1400a at predetermined angles with respect to the gravity direction so that the lasers L to be output are oriented to landing positions of the materials M. Thus the lasers L are radiated from the laser radiation units <NUM> to the landed materials M and the materials M are baked and sintered so that sintered portions <NUM> are formed. An aggregate of the sintered portions <NUM> is formed as a partial fabricated object of the three-dimensional fabricated object <NUM> formed on the sample plate <NUM>, for example, the partial fabricated object <NUM> (see <FIG>).

<FIG> are plan views (in the direction indicated by the arrow D illustrated in <FIG>) conceptually illustrating a relation between disposition of the head units <NUM> and form shapes of sintered portions <NUM>. First, as illustrated in <FIG>, the material M is ejected from the ejection nozzles 1230a of the head units <NUM> and <NUM> at a fabrication start point q1 on the sample plate <NUM> and the lasers L are radiated from the laser radiation units <NUM> to the materials M landed to the sample plate <NUM>, so that sintered portions 50a and 50b are formed. To facilitate the description, the sintered portions <NUM> are hatched even in the plan views. The first partial fabricated object <NUM> formed on the upper surface of the sample plate <NUM> will be exemplified in the description.

First, as illustrated in <FIG>, the materials M are ejected from the material ejection units <NUM> included in the first head units <NUM> and <NUM> illustrated on the lower side at the fabrication start point q1 of the partial fabricated object <NUM> on the sample plate <NUM>. The lasers L are radiated from the laser radiation units <NUM> included in the head units <NUM> and <NUM> to the ejected materials M, so that the sintered portions 50a and 50b are formed.

While the materials M are continuously ejected from the material ejection units <NUM> of the head units <NUM> and <NUM> and the lasers L are continuously radiated from the laser radiation units <NUM>, the sample plate <NUM> is moved in the Y (+) direction relative to the head base <NUM> up to a position at which the fabrication start point q1 illustrated in <FIG> corresponds to the second head units <NUM> and <NUM>. Accordingly, the sintered portions 50a and 50b extend from the fabrication start point q1 to a position q2 after the relative movement of the sample plate <NUM> so that the sintering width t is maintained. Further, the materials M are ejected from the second head units <NUM> and <NUM> corresponding to the fabrication start point q1 and the lasers L are radiated to the materials M, so that sintered portions 50c and 50d start to be formed.

The sintered portions 50c and 50d illustrated in <FIG> start to be formed, and while the materials M are continuously ejected from the material ejection units <NUM> of the head units <NUM> and <NUM>, and the lasers L are continuously radiated from the laser radiation units <NUM>, the sample plate <NUM> is moved in the Y (+) direction relative to the head base <NUM> up to a position at which the fabrication start point q1 illustrated in <FIG> corresponds to the third head units <NUM> and <NUM>. Accordingly, the sintered portions 50c and 50d extend from the fabrication start point q1 to the position q2 after the relative movement of the sample plate <NUM> so that the sintering width t is maintained. Simultaneously, the sintered portions 50a and 50b extend from the fabrication start point q1 to a position q3 after the relative movement of the sample plate <NUM> so that the sintering width t is maintained. The materials M are ejected from the third head units <NUM> and <NUM> corresponding to the fabrication start point q1 and the lasers L are radiated to the materials M, so that sintered portions 50e and 50f start to be formed.

The sintered portions 50e and 50f illustrated in <FIG> start to be formed, and while the materials M are continuously ejected from the material ejection units <NUM> of the head units <NUM> and <NUM>, and the lasers L are continuously radiated from the laser radiation units <NUM>, the sample plate <NUM> is moved in the Y (+) direction relative to the head base <NUM> up to a position at which the fabrication start point q1 illustrated in <FIG> corresponds to the fourth head units <NUM> and <NUM>. Accordingly, the sintered portions 50e and 50f extend from the fabrication start point q1 to the position q2 after the relative movement of the sample plate <NUM> so that the sintering width t is maintained. Simultaneously, the sintered portions 50a and 50b extend from the fabrication start point q1 to a position q4 after the relative movement of the sample plate <NUM> and the sintered portions 50c and 50d extend from the fabrication start point q1 to the position q3 after the relative movement of the sample plate <NUM> so that the sintering width t is maintained. The materials M are ejected from the fourth head units <NUM> and <NUM> corresponding to the fabrication start point q1 and the lasers L are radiated to the materials M, so that sintered portions <NUM> and <NUM> start to be formed.

In a case in which the position q5 is set to a sintering end position (hereinafter the position q5 is referred to as the fabrication end point q5), as illustrated in <FIG>, the sample plate <NUM> is relatively moved until the head units <NUM> and <NUM> reach the fabrication end point q5, so that the sintered portions <NUM> and <NUM> extend. In the head units <NUM> and <NUM> reaching the fabrication end point q5, the ejection of the materials M from the material ejection units <NUM> included in the head units <NUM> and <NUM> and the radiation of the lasers L from the laser radiation units <NUM> are stopped. Further, while the sample plate <NUM> is relatively moved in the Y (+) direction, the lasers L are radiated until the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> reach the fabrication end point q5. Thus the sintered portions 50a, 50b, 50c, 50d, 50e, 50f, <NUM>, and <NUM> are formed from the fabrication start point q1 to the fabrication end point q5 so that the sintering width t is maintained, as illustrated in <FIG>. In this way, while the sample plate <NUM> is moved from the fabrication start point q1 to the fabrication end point q5, the materials M are ejected and supplied and the lasers L are radiated sequentially from the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, so that the substantially rectangular sintered portions <NUM> with a width T and a length J can be formed in the example of the embodiment. Accordingly, the partial fabricated object <NUM> of the first layer can be formed and configured as the aggregate of the sintered portions <NUM>.

As described above, the forming apparatus <NUM> according to the second embodiment selectively performs the ejection and supply of the materials M from the material ejection units <NUM> included in the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> and the radiation of the lasers L from the laser radiation units <NUM> in synchronization with the movement of the stage <NUM> including the sample plate <NUM>, so that the partial fabricated object <NUM> with a desired shape can be formed on the sample plate <NUM>. As described above, by merely moving the stage <NUM> in one direction of the Y axis direction in this example when the stage <NUM> is moved, it is possible to obtain the sintered portions <NUM> with the desired shape in a region with the width T × the length J illustrated in <FIG> and the partial fabricated object <NUM> as the aggregate of the sintered portions <NUM>.

As the materials M ejected from the material ejection units <NUM>, different materials from the head units can also be ejected and supplied from one unit or two or more units of the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Accordingly, the forming apparatus <NUM> according to the embodiment can be used to obtain the three-dimensional fabricated objects including composite partial fabricated objects formed from different kinds of materials.

The number and arrangement of the head units <NUM> disposed in the head base <NUM> included in the forming apparatus <NUM> according to the above-described first embodiment or the number and arrangement of the head units <NUM> disposed in the head base <NUM> included in the forming apparatus <NUM> according to the second embodiment are not limited to the above-described number and arrangement illustrated in <FIG> or <FIG>. <FIG> schematically illustrate examples not according to the invention of other dispositions of the head units <NUM> or <NUM> disposed in the head base <NUM> or <NUM>.

<FIG> illustrates a form in which the plurality of head units <NUM> or <NUM> are arranged in a line in the X axis direction in the head base <NUM> or <NUM>. <FIG> illustrates a form in which the head units <NUM> or <NUM> are arranged in a lattice form in the head base <NUM> or <NUM>. The number of head units arranged in either example is not limited to the illustrated example.

A three-dimensional forming method of forming a three-dimensional fabricated object using the three-dimensional forming apparatus <NUM> according to the first embodiment will be described according to a third embodiment. <FIG> is a flowchart illustrating the three-dimensional forming method according to the third embodiment. <FIG> is a schematic diagram illustrating the configuration of a green sheet forming apparatus that forms the green sheet <NUM>. <FIG>, 14A, and 14B are schematic plan views and sectional views illustrating steps of the three-dimensional forming method according to the embodiment. <FIG> are external perspective views and schematic sectional views illustrating steps of the three-dimensional forming method according to the embodiment.

As illustrated in <FIG>, in the three-dimensional forming method according to the embodiment, a three-dimensional fabrication data acquisition process (S1) of acquiring three-dimensional fabrication data of the three-dimensional fabricated object from, for example, a personal computer (not illustrated) by the control unit <NUM> (see <FIG>) is performed. As the three-dimensional fabrication data acquired in the three-dimensional fabrication data acquisition process (S1), control data is transmitted from the control unit <NUM> to the stage controller <NUM>, the material supply device controller <NUM>, and the laser controller <NUM>, and then the process proceeds to a material preparation process.

In a material preparation process (S2), a predetermined number of green sheets <NUM> are placed on the supply table <NUM> included in the material supply device <NUM>. The green sheets <NUM> are formed by a green sheet forming apparatus <NUM> or the like of the green sheets <NUM>, as a schematic configuration is exemplified in <FIG>.

As illustrated in <FIG>, the green sheet forming device <NUM> includes a raw material supply unit <NUM> that supplies a material M and a transfer belt <NUM> that receives the material M discharged from the raw material supply unit <NUM> and transfers the material M. A mixture in which a metal powder formed with a size equal to or less than <NUM> and a binder are kneaded and formed in a paste form is used as the material M. As the metal powder, for example, an alloy such as a cobalt-based alloy, maraging steel, stainless steel, a titanium-based alloy, a nickel-based alloy, a magnesium alloy, or a copper-based alloy, or a metal such as iron, titanium, nickel, or copper can be used. As the binder, a thermoplastic resin or a thermoplastic water-soluble resin can be used. As the thermoplastic resin, for example, polylactic acid (PLA), polypropylene (PP), polyphenylene sulfide (PPS), polyamide (PA), ABS, or polyether ether ketone (PEEK) is used. As the thermoplastic water-soluble resin, for example, polyvinyl alcohol (PVA) or polyvinyle butyral (PVB) is used.

The material M in which the above-described metal powder and binder and a solvent for viscosity adjustment are added and kneaded is input to the raw material supply unit <NUM>, and a predetermined amount of material M is sequentially discharged to the transfer belt <NUM> driven in an illustrated arrow α direction. With the movement of the transfer belt <NUM> in the α direction, the thickness of the material M is equalized by an equalizing roll <NUM>, the material M passes through a subsequent pressurization roller <NUM> so that the material M has a predetermined thickness for the green sheet <NUM>. Then, the material M is cut out in a predetermined length by a cutting unit <NUM> to obtain the green sheet <NUM>.

When the predetermined number of green sheets <NUM> are placed on the supply table <NUM> of the material supply device <NUM> in the material preparation process (S2), a material supply process (S3) starts. In the material supply process (S3), the material supply device controller <NUM> generates a driving signal of the transfer device <NUM> based on a control signal from the control unit <NUM> and drives the transfer device <NUM>.

First, the sheet holding unit 230a is moved up to a predetermined position, and the uppermost sheet of the green sheets <NUM> stacked on the supply table <NUM> is adsorbed and held by the sheet adsorption unit 230c. The sheet holding unit 230a is moved to the sample plate <NUM> of the sintering device <NUM> while holding the green sheet <NUM>, the green sheet <NUM> is detached and separated from the sheet adsorption unit 230c, and the green sheet <NUM> is placed on the sample plate <NUM>. After the green sheet <NUM> is placed and separated, the sheet holding unit 230a returns to a standby position of the material supply device <NUM>. Hereinafter, the green sheet <NUM> placed as a first layer will be described as a first layer green sheet <NUM>.

The process proceeds to a sintering process (S4) in which the lasers L are radiated from the laser radiation units <NUM> included in the plurality of head units <NUM> held in the head base <NUM> to the green sheet <NUM> of the first layer placed on the sample plate <NUM> in the material supply process (S3).

The sintering in the sintering process (S4) is a process of removing the binder from the state in which the metal powder and the binder included in the green sheet <NUM> are included, bonding the metal powder, and forming a metal fabricated object.

In <FIG>, and 14A, a method of forming a sintered portion <NUM> of the green sheet <NUM> of the first layer in the sintering process (S3) is illustrated. In this example, a method of forming the partial fabricated object <NUM> of the first layer in a circular state included in the three-dimensional fabricated object <NUM> is exemplified. 13A to 14B, plan views are illustrated on the upper sides and sectional views taken along the line F-F' illustrated in the plan views are illustrated on the lower sides.

As illustrated in <FIG>, while moving the head base <NUM> in the Y direction relative to the green sheet <NUM> of the first layer placed on the sample plate <NUM> included on the stage <NUM>, the lasers L are radiated toward the green sheet <NUM> from the laser radiation units <NUM> included in the head units <NUM> (not illustrated in the drawing) disposed in the head base <NUM>.

When the relative movement of the head base <NUM> by a predetermined amount ends, sintered portions <NUM> are formed as a aggregate of the sintered portions corresponding to the sintered portions 310a, 310b, 310c, 310d, 310e, and 310f formed at the time of the radiation from the laser radiation units <NUM>, as described in <FIG>, so that the first sintered portion <NUM> included in the partial fabricated object <NUM> is formed. As illustrated in <FIG>, the head base <NUM> forms the aggregate of the sintered portions corresponding to the sintered portions 310a, 310b, 310c, 310d, 310e, and 310f formed at the time of the radiation from the laser radiation units <NUM>, as described in <FIG>, to be continuous with the sintered portions <NUM> illustrated in <FIG>, so that a sintered portion <NUM> is formed and thus a sintered portion <NUM> joined to the sintered portion <NUM> is formed.

As illustrated in <FIG>, the head base <NUM> forms the aggregate of the sintered portions corresponding to the sintered portions 310a, 310b, 310c, 310d, 310e, and 310f formed at the time of the radiation from the laser radiation units <NUM>, as described in <FIG>, to be continuous with the sintered portions <NUM> illustrated in <FIG> a predetermined number of times repeatedly in sequence. Then, as illustrated in <FIG>, an i-th sintered portion 31i in which the sintered portion <NUM> is formed until the shape of the partial fabricated object <NUM> is formed, and thus the partial fabricated object <NUM> and a portion excluding the partial fabricated object <NUM>, that is, an unsintered portion 301a, are formed in the green sheet <NUM> of the first layer.

In this way, the sintered partial fabricated object <NUM> and the unsintered portion 301a are formed in the sintering process (S4), so that a first layer 301b is formed as a first single layer. The above-described series of processes from the material supply process (S3) and the sintering process (S4) is a single layer forming process (S100). Then, the sintering process (S4) ends, that is, the single layer forming process (S100) ends and the process proceeds to a subsequent stack number comparison process.

After the first layer 301b including the partial fabricated object <NUM> which is the first layer, and the unsintered portion 301a is formed in the single layer forming process (S100), the process proceeds to a stack number comparison process (S5) of performing comparison with fabrication data obtained in the three-dimensional fabrication data acquisition process (S1). In the stack number comparison process (S5), a stack number N of green sheets <NUM> in which partial fabricated objects are formed and which are necessary to form the three-dimensional fabricated object <NUM> is compared to a stack number n of green sheets <NUM> stacked up to the single layer forming process (S100) immediately before the stack number comparison process (S5). When n < N is determined in the stack number comparison process (S5), the process proceeds to a stacking process of performing the single layer forming process (S100) again.

A stacking process (S6) is an instruction process of performing the single layer forming process (S100) again when n < N is determined in the stack number comparison process (S5). The material supply process (S3) which is a start process of the single layer forming process (S100) is performed.

As illustrated in <FIG>, the green sheet <NUM> is supplied to be placed on the upper portion of the first layer 301b through the stacking process (S6) and becomes a green sheet <NUM> of a second layer. Then, in the same way as illustrated in <FIG>, and <FIG>, the sintering process (S5) is performed on the green sheet <NUM> of the second layer, so that a second layer 302b can be obtained as a second single layer in which a partial fabricated object <NUM> of the second layer and a unsintered portion (not illustrated) are formed. Thereafter, the process proceeds to the stack number comparison process (S6). When n < N is determined, the stacking process (S6) starts again. The stacking process (S6) and the single layer forming process (S100) are repeated until n = N is determined in the stack number comparison process (S5).

As illustrated in <FIG>, when the predetermined stack number N is stacked, the three-dimensional fabricated object <NUM> is formed on the sample plate <NUM>. Unsintered portions 300a stacked to be formed from the first layer 301b to an N-th layer 30Nb are also formed on the sample plate <NUM>. Then, when n = N is determined in the stack number comparison process (S5), the process proceeds to an unsintered portion removal process.

An unsintered portion removal process (S7) is a process of removing portions excluding the three-dimensional fabricated object <NUM>, that is, the unsintered portions 300a. As the method of removing the unsintered portions 300a, for example, a mechanical removal method or a method of dissolving the binder including the unsintered portions 300a using a solvent and removing the remaining metal powder can be applied. In the embodiment, the mechanical removal method will be described as an example.

As illustrated in <FIG>, in the unsintered portion removal process (S7), the unsintered portions 300a are removed on the sample plate <NUM> by striking the unsintered portions 300a with a removal tool <NUM> with a wedge-shaped tip end and breaking the unsintered portions 300a. Then, the three-dimensional fabricated object <NUM> remains on the sample plate <NUM> and is extracted. In the embodiment, the case in which the unsintered portion removal process (S7) is performed on the sample plate <NUM> has been described, but the unsintered portion removal process may be performed on a separately provided work stand.

In the three-dimensional forming method for the three-dimensional fabricated object <NUM> according to the above-described third embodiment, in the sintering process (S5) of the single layer forming process (S100), the sintered portions <NUM> can be formed in a broad region merely by moving the head base <NUM> relative to the stage <NUM> in one direction, in this example, the Y axis direction since the plurality of head units <NUM> including the laser radiation units <NUM> are included in the head base <NUM> included in the sintering device <NUM>. Thus, it is possible to obtain the three-dimensional forming method with high productivity.

A three-dimensional forming method of forming a three-dimensional fabricated object using the three-dimensional forming apparatus <NUM> according to the second embodiment will be described according to a fourth embodiment. <FIG> is a flowchart illustrating the three-dimensional forming method according to the fourth embodiment. <FIG>, 18A, and 18B are diagrams illustrating a three-dimensional forming process according to the embodiment and schematic plan views on the upper sides and schematic sectional views taken along the line G-G' illustrating the schematic plan views on the lower sides.

As illustrated in <FIG>, in the three-dimensional forming method according to the embodiment, a three-dimensional fabrication data acquisition process (S10) of acquiring three-dimensional fabrication data of the three-dimensional fabricated object <NUM> from, for example, a personal computer (not illustrated) by the control unit <NUM> (see <FIG>) is performed. As the three-dimensional fabrication data acquired in the three-dimensional fabrication data acquisition process (S10), control data is transmitted from the control unit <NUM> to the stage controller <NUM>, the material supply controller <NUM>, and the laser controller <NUM>, and then the process proceeds to a single layer forming process.

In a single layer forming process (S110), a material supply process (S20) and a sintering process (S30) are performed over a region in which the partial fabricated object <NUM> of the first layer is formed. In the material supply process (S20), the materials M are ejected in the liquid droplet form toward the sample plate <NUM> from the material ejection units <NUM> held in the plurality of head units <NUM> included in the head base <NUM>, and thus the materials M are landed to a predetermined formation region on the sample plate <NUM>.

When the materials M are landed to be formed on the sample plate <NUM> in the material supply process (S20), the process proceeds to the sintering process (S30). In the sintering process (S30), the lasers L are radiated from the laser radiation units <NUM> held by the head units <NUM> to the materials M supplied in the liquid droplet form in the material supply process (S20), and thus the materials M are baked and sintered so that sintered portions <NUM> are formed.

As described with respect to <FIG> and shown in <FIG>, the head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> form the aggregate of the sintered portions corresponding to the sintered portions 50a, 50b, 50c, 50d, 50e, 50f, <NUM>, and <NUM> by moving the head base <NUM> in the Y axis direction relative to the stage <NUM> on which the sample plate <NUM> is placed while repeating the material supply process (S20) and the sintering process (S30) in a predetermined region, and thus the initial sintered portions <NUM> of the partial fabricated object <NUM> are formed as a sintered portion <NUM>.

Further, as illustrated in <FIG>, the head base <NUM> is moved in the X axis direction relative to the stage <NUM> at a position at which the sintered portions corresponding to the sintered portions 50a, 50b, 50c, 50d, 50e, 50f, <NUM>, and <NUM> are formed to be continuous with the sintered portion <NUM> illustrated in <FIG>. The head units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> form the aggregate of the sintered portions corresponding to the sintered portions 50a, 50b, 50c, 50d, 50e, 50f, <NUM>, and <NUM> by moving the head base <NUM> in the Y axis direction relative to the stage <NUM> on which the sample plate <NUM> is placed while repeating the material supply process (S20) and the sintering process (S30) in a predetermined region, and thus the sintered portions <NUM> are formed as a sintered portion <NUM> continuous with the sintered portion <NUM>. That is, the sintered portions <NUM> are formed by the sintered portions <NUM> and <NUM>.

As illustrated in <FIG> described above, sintered portions are sequentially formed to be continuous with the preceding sintered portions so that the sintered portion <NUM> is formed to be continuous with the earlier formed sintered portion <NUM>. As illustrated in <FIG>, an i-th sintered portion 51i in which the sintered portion <NUM> is formed until the shape of the partial fabricated object <NUM> is formed, and thus the partial fabricated object <NUM> of the first layer of the three-dimensional fabricated object <NUM> is formed on the sample plate <NUM>.

As described above, in the embodiment, when the partial fabricated object <NUM> of the first layer is formed repeating the material supply process (S20) and the sintering process (S30) while moving the head base <NUM> in the Y axis direction and the X axis direction relative to the sample plate <NUM>, the single layer forming process (S110) ends. Then, the process proceeds to a subsequent stack number comparison process.

When the partial fabricated object <NUM> which is the first layer is formed as a first single layer in the single layer forming process (S110), the process proceeds to a stack number comparison process (S40) of performing comparison with fabrication data obtained in the three-dimensional fabrication data acquisition process (S10). In the stack number comparison process (S40), a stack number N of partial fabricated objects included in the three-dimensional fabricated object <NUM> is compared to a stack number n of partial fabricated objects stacked up to the single layer forming process (S110) immediately before the stack number comparison process (S40). When n < N is determined in the stack number comparison process (S40), the process proceeds to a stacking process of performing the single layer forming process (S110) again.

In the stack number comparison process (S40) after the partial fabricated object <NUM> of the first layer is formed as the first single layer illustrated in <FIG>, when the stack number n = <NUM> and the three-dimensional fabricated object <NUM> includes the stack number N of partial fabricated objects > <NUM>, n < N is determined and the process proceeds to s stacking process.

A stacking process (S50) is an instruction process of performing the single layer forming process (S110) again when n < N is determined in the stack number comparison process (S40). When the process proceeds to the single layer forming process (S110), as illustrated in <FIG>, the head base <NUM> and the stage <NUM> are driven to start forming the partial fabricated object <NUM> on the upper portion of the partial fabricated object <NUM> of the first layer in the stacking process (S50) at a position at which the material supply process (S20) and the sintering process (S30) start based on the three-dimensional fabrication data corresponding to the partial fabricated object <NUM> of the second layer which is the second single layer.

When the forming of the partial fabricated object <NUM> of the second layer ends, the process proceeds to the stack number comparison process (S40) again. Until n = N, the process proceeds to the stacking process (S50) and the single layer forming process (S110) is repeated to form the three-dimensional fabricated object <NUM>.

In the three-dimensional forming method for the three-dimensional fabricated object <NUM> according to the above-described fourth embodiment, in the material supply process (S20) and the sintering process (S30) of the single layer forming process (S110), the sintered portions <NUM> can be formed in a broad region merely by moving the head base <NUM> relative to the stage <NUM> in one direction, in this example, the Y axis direction since the plurality of head units <NUM> including the material ejection units <NUM> and the laser radiation units <NUM> are included in the head base <NUM> included in the forming apparatus <NUM>. Thus, it is possible to obtain the three-dimensional forming method with high productivity.

Since the plurality of different kinds of sintered materials are accommodated in the material accommodation units 1210a in the material supply unit <NUM> included in the forming apparatus <NUM> illustrated in <FIG>, the three-dimensional fabricated object <NUM> formed of different kinds of materials can be easily obtained.

A three-dimensional forming method according to a fifth embodiment will be described. In the three-dimensional forming method according to the above-described fourth embodiment, when the three-dimensional fabricated object has an overhang, there is no partial fabricated object of the lower layer to which the materials M ejected from the material ejection units <NUM> are to be landed in the overhang, and thus the materials M are not formed in the material supply process (S20) of the above-described single layer forming process (S110) (see <FIG>). When a region in which the partial fabricated object <NUM> of the first layer which is the partial fabricated object of the lower layer illustrated in <FIG> is not disposed in the fabrication region of the partial fabricated object <NUM> of the second layer is present, there is a concern of the partial fabricated object <NUM> being deformed and hanging down in the gravity direction in the portion. That is, the material M before the sintering is a material in a slurry state (or a paste form) obtained by kneading an elementary powder of a metal which is the raw material, for example, an alloy of stainless steel and titanium, or a mixed powder of stainless steel and copper (Cu) which are difficult to alloy, an alloy of stainless and titanium, or a titanium alloy and cobalt (Co) or chrome (Cr) with a solvent and a thickener.

Accordingly, a method of forming a three-dimensional fabricated object without deforming an overhang by the three-dimensional forming method according to the fifth embodiment will be described. The same reference numerals are given to the same processes as those of the three-dimensional forming method according to the fourth embodiment, and the description thereof will be omitted. To facilitate the description, as illustrated in the external plan view of <FIG> and the sectional view of <FIG> taken along the line K-K' illustrated in <FIG>, a three-dimensional fabricated object <NUM> with a simple shape will be exemplified to describe the three-dimensional forming method according to the fifth embodiment, but the invention is not limited to this shape. The invention can be applied when a fabricated object has a so-called overhang.

As illustrated in <FIG>, the three-dimensional fabricated object <NUM> includes a flange portion 700c which is an overhang extending to the outer side of a base portion 700b in an concave opening-side end of the columnar base portion 700b including a concave portion 700a. To form the three-dimensional fabricated object <NUM> based on the three-dimensional forming method according to the fifth embodiment, fabrication data for which support portions <NUM> to be removed in a forming process reach the bottom portion of the base portion 700b in the illustrated lower direction of the flange portion 700c is added to three-dimensional fabrication data of the three-dimensional fabricated object <NUM> for generation.

<FIG> is a flowchart illustrating a method of forming the three-dimensional fabricated object <NUM> illustrated in <FIG>. <FIG> illustrate a method of forming the three-dimensional fabricated object <NUM> in the flowchart illustrated in <FIG>, and partial sectional views and external plan views are illustrated on the left side and the right side of the drawings, respectively. In the three-dimensional fabricated object <NUM> according to the embodiment, an example in which four layers are stacked and formed will be described, but the invention is not limited thereto.

As illustrated in <FIG>, first, a partial fabricated object <NUM> which is a first layer is formed on the sample plate <NUM> (not illustrated) by the three-dimensional forming method according to the fourth embodiment. In the process of forming the partial fabricated object <NUM>, partial support portions <NUM> of the first layer are also formed. The sintering process (S30) of the single layer forming process (S110) described with reference to Figs. 17A to 18B is not performed on the partial support portions <NUM>, and the single layer forming process (S110) is performed with the material M remaining, that is, unsintered or unmelted.

Subsequently, the single layer forming process (S110) is repeated to form partial fabricated objects <NUM> and <NUM> which are second and third layers, as illustrated in <FIG>. Then, in a process of forming the partial fabricated objects <NUM> and <NUM>, partial support portions <NUM> and <NUM> of the second and third layers are also formed. As in the partial support portion <NUM>, the sintering process (S30) of the single layer forming process (S110) is not performed on the partial support portions <NUM> and <NUM>, and the single layer forming process (S110) is performed with the material M remaining, that is, unsintered or unmelted, so that the support portions <NUM> are formed by the partial support portions <NUM>, <NUM>, and <NUM>.

Next, as illustrated in <FIG>, a partial fabricated object <NUM> of a fourth layer formed in the flange portion 700c is formed. The partial fabricated object <NUM> is formed to be supported by ends 710a of the support portions <NUM> formed by the partial support portions <NUM>, <NUM>, and <NUM>. By forming the partial fabricated object <NUM> in this way, the ends 710a are formed as surfaces to which the material M (see <FIG>) is landed, so that the partial fabricated object <NUM> of the fourth layer which becomes the flange portion 700c can be formed accurately.

Then, as illustrated in <FIG>, when the three-dimensional fabricated object <NUM> is fabricated, the support portions <NUM> are removed from the three-dimensional fabricated object <NUM> in the support portion removal process (S60). Since the support portions <NUM> are formed of an unbaked material, the support portions <NUM> can be physically cut by, for example, a sharp-edged tool <NUM> which is a removal unit for the support portions <NUM> in a support portion removal process (S60), as illustrated in <FIG>. Alternatively, the three-dimensional fabricated object <NUM> may be removed by performing immersing in a solvent and dissolving the thickener included in the material.

As described above, when the three-dimensional fabricated object <NUM> including the flange portion 700c which is the overhang is formed, it is possible to prevent the flange portion 700c from being deformed in the gravity direction by forming the support portions <NUM> supporting the flange portion 700c in conjunction with the forming of the three-dimensional fabricated object <NUM>. The support portions <NUM> illustrated in <FIG> are not limited to the form in which the illustrated flange portion 700c is supported (sustained) on the entire surface, but the shapes, sizes, and the like of the support portions are set according to the shape of the fabricated object, a material composition, or the like.

Claim 1:
A three-dimensional forming apparatus (<NUM>) comprising:
a stage (<NUM>);
a material supply unit (<NUM>) configured to supply the stage with a sintering material (<NUM>);
a plurality of head units (<NUM>) that each includes an energy radiation unit for supplying energy (<NUM>) capable of sintering the sintering material supplied by the material supply unit;
a head base (<NUM>) that holds the plurality of head units; and
a driving unit (<NUM>) that is capable of three-dimensionally moving the head base relative to the stage,
wherein the head base (<NUM>) holds a first pair of head units (<NUM>,<NUM>), a second pair of head units (<NUM>,<NUM>) and a third pair of head units (<NUM>,<NUM>), and
each of the first to third pairs of head units forms a respective line of head units arranged along a first direction (X) and fastened to the head base (<NUM>), characterized in that
the sintering material (<NUM>) includes metal powder and a binder,
the first to third pairs of head units together form two parallel lines, with three single head units in each of the parallel lines, and
each of the plurality of head units (<NUM>) is configured to produce a corresponding sintered portion (<NUM>), such that the sintered portion corresponding to each of the head units in each of the first to third pairs of head units is adjacent to the sintered portion corresponding to one of the head units in an adjacent one of the first to third pairs of head units in a case that the driving unit moves the head base along a single second direction (Y) perpendicular to the first direction,
whereby a part of a configuration of a three-dimensional fabricated object is formed as an aggregate of the sintered portions (<NUM>) formed by the energy radiated from the energy radiation units (<NUM>) included in the plurality of head units (<NUM>) as the head base is moved along the single second direction (Y).