Patent Description:
As a three-dimensional fabricating apparatus that fabricates a solid (three-dimensional) object, there is known a three-dimensional fabricating apparatus that uses an additive fabricating method, for example. In the additive fabricating method, for example, flattened metal or non-metal powder is formed into a layer on a fabrication stage (hereinafter, referred to as fabrication chamber), a fabrication liquid is discharged to the layered powder (hereinafter, referred to as "powder layer") to form a layered fabrication object (hereinafter, referred to as "fabrication layer") in which powder particles are bonded together, and another powder layer is formed on the fabrication layer to form another fabrication layer, and these steps are repeated to laminate fabrication layers one on another, thereby fabricating a three-dimensional object.

As a conventional technique, there is disclosed a technique for automatically collecting powder generated at the outer edge portion of a fabrication chamber (hereinafter, referred to as excess powder) at the time of flattening the surface of the powder layer. By this technique, the excess powder is diffused by a roller and dropped into a groove provided beside the fabrication chamber, and the powder accumulated in the groove is conveyed and collected by a slider or a brush (see <CIT> (<CIT>), for example).

<CIT> discloses a device for removing powder from the side of the powder cylinder.

An object of the present disclosure is to provide a method for fabricating a three-dimensional object, including highly efficiently collecting excess powder and exerting high cleaning performance.

According to an embodiment of the present disclosure, a method of fabricating a three-dimensional object includes supplying, flattening, and collecting. The supplying supplies, with a powder supplier, powder to a fabrication chamber. The fabrication chamber includes a fabrication stage to store powder and an outer edge portion outside the fabrication stage, the outer edge portion having one bottom surface. The flattening flattens, with a flattener, the powder supplied by the supplying. The collecting collects, with a powder collector, the powder having overflowed from the fabrication stage to the outer edge portion by the flattening into the fabrication stage.

According to another embodiment of the present disclosure, an apparatus for fabricating a three-dimensional object includes a fabrication chamber, a powder supplier, a flattener, and a powder collector. The fabrication chamber includes a fabrication stage to store powder and an outer edge portion outside the fabrication stage. The powder supplier supplies the powder to the fabrication chamber. The flattener flattens the powder supplied by the powder supplier. The powder collector collects, into the fabrication stage, the powder having overflowed from the fabrication stage to the outer edge portion by the flattener.

According to an embodiment of the present disclosure, it is possible to provide a method for fabricating a three-dimensional object, including highly efficiently collecting excess powder and exerting high cleaning performance.

The three-dimensional object fabricating method of the present disclosure includes a powder supply step, a flattening step, and a powder collection step, and further includes other steps as necessary.

The three-dimensional object fabricating apparatus of the present disclosure includes a fabrication chamber, a powder supplier, a flattener, and a powder collector, and further includes other units as necessary.

The powder supply step is performed by the powder supplier, the flattening step is performed by the flattener, and the powder collection step is performed by the powder collector.

In the related art, the excess powder is collected using a slider. However, since there is a groove provided on the side of the fabrication chamber (the outer edge portion of the fabrication chamber has two bottom surfaces), there is a disadvantage that it is difficult to completely collect the powder fallen into the groove by machinery alone, and finally, the user needs to collect the powder in the groove by a suction device or the like. Furthermore, it is structurally difficult to completely suck the powder in the groove, and there is a disadvantage that roller banding may occur during fabrication and recoating due to the powder gradually accumulated in the groove, which results in deterioration of fabrication quality. There is also disadvantage that providing the groove complicates the structure and causes a cost increase.

In the present disclosure, since the outer edge portion of the fabrication chamber has one bottom surface, that is, no groove is provided in the outer edge portion of the fabrication chamber, the excess powder is collected with high efficiency and high cleaning performance is obtained. Thus, the occurrence of roller banding due to the accumulation of the powder can be prevented to improve the fabrication quality.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. An outline of an example of a three-dimensional object fabricating apparatus of the present disclosure will be described with reference to <FIG>.

As illustrated in <FIG>, the three-dimensional object fabricating apparatus of the present disclosure includes a fabrication chamber <NUM> having a fabrication stage 11a that stores powder and an outer edge portion 11b outside the fabrication stage, a powder supplier <NUM>, a flattener <NUM>, and a powder collector <NUM>.

The fabrication chamber <NUM> has the fabrication stage 11a that stores the powder at the bottom. The fabrication stage 11a is movable up and down in a vertical direction (height direction), and a three-dimensional object with a stack of fabrication layers is fabricated on the fabrication stage 11a.

The fabrication chamber <NUM> includes the outer edge portion 11b outside the fabrication stage. The powder overflowing from the fabrication stage 11a (hereinafter, also referred to as excess powder) moves to the outer edge portion 11b by a flattening process by a flattener described later.

The outer edge portion 11b has one bottom surface. That is, the outer edge portion 11b does not have a groove, so that the excess powder moved to the outer edge portion 11b by the flattening process can be collected to the fabrication stage with high efficiency by a powder collection process described later. Since the outer edge portion 11b has no groove, it is possible to prevent the remaining excess powder from accumulating on the outer edge portion 11b, and thus, it is not necessary to collect the powder by a suction device or the like.

The outer edge portion 11b preferably has at least one vertical wall. Accordingly, at the time of recoating (flattening) and powder collection, it is possible to prevent the excess powder from overflowing from the outer edge portion 11b, that is, from the three-dimensional object fabricating apparatus.

The height of the vertical wall of the outer edge portion 11b is not limited in particular, and can be appropriately selected according to the purpose. However, it is preferably the same as or lower than the height of the surface of the powder flattened (recoated) by the flattener described later. This narrows the gap between the ink jet head and the flattened surface of the powder, so that the lifting operation of the fabrication stage 11a can be omitted to improve the productivity of the three-dimensional object.

The distance of the gap between the vertical wall of the outer edge portion 11b and the powder collector described later is not limited in particular, and can be appropriately selected according to the purpose, but is preferably <NUM> or more. When the distance is <NUM> or more, it is possible to suppress non-slidability due to friction generated by intrusion of the powder into the gap between the vertical wall and the powder collector, so that the powder collector moves smoothly.

The flattener <NUM> transfers and supplies the powder to the fabrication chamber <NUM>, and flattens the surface to form a powder layer which is a layered powder with a predetermined thickness.

The flattener <NUM> has a rod-like shape longer than the inner dimension of the fabrication chamber <NUM> (that is, the width of the portion to which the powder is supplied or the portion into which the powder is charged), and is reciprocated in the sub-scanning direction along the surface of the fabrication stage 11a by a reciprocating mechanism.

The flattener <NUM> horizontally moves so as to pass above the fabrication chamber <NUM> while being rotated by the motor. Accordingly, the powder is transferred and supplied onto the fabrication chamber <NUM>, and the flattener <NUM> flattens the powder while passing over the fabrication chamber <NUM>, thereby forming a powder layer.

The flattener <NUM> is not limited in particular, and can be appropriately selected according to the purpose, and examples thereof include a plate member, a roller member, and the like.

The flattener <NUM> is preferably attached directly or indirectly to the powder collector <NUM> described later. The recoating (flattening) and the collection of the excess powder can be performed simultaneously by moving the flattener <NUM> to which the powder collector <NUM> is attached.

The three-dimensional object fabrication apparatus preferably includes the flattener <NUM> and another flattener <NUM> in front of and behind the powder supplier <NUM> in a sub-scanning direction of the powder supplier <NUM>.

The powder collector <NUM> is preferably located on the outer edge portion 11b in the fabrication chamber <NUM> of the three-dimensional object fabricating apparatus of the present disclosure, and is preferably located at both ends of the three-dimensional object fabricating apparatus. Thus, the excess powder on the outer edge portion 11b can be moved into the fabrication chamber <NUM>.

The shape of the powder collector <NUM> is not limited in particular, and can be appropriately selected according to the purpose, and exampHles thereof include a plate-like member and the like.

The powder collector <NUM> preferably has an inclined face (an oblique cut) having a rear end closer to the fabrication chamber <NUM> than a front end in an advance direction of the powder collector <NUM>. Thus, when the excess powder on the outer edge portion 11b is collected, the excess powder can be preferentially moved and collected onto the fabrication stage 11a.

The angle of the oblique cutting is not limited in particular, and can be appropriately selected according to the purpose, but is preferably <NUM>° or more and <NUM>° or less. Thus, the excess powder can be more preferentially moved and collected onto the fabrication stage 11a.

As illustrated in <FIG>, the powder collector <NUM> is preferably directly or indirectly attached to the flattener <NUM>. The recoating (flattening) and the collecting of the excess powder can be performed simultaneously by moving the flattener <NUM> to which the powder collector <NUM> is attached.

The material of the powder collector <NUM> is not limited in particular, and can be appropriately selected according to the purpose, and examples thereof include metal and the like. The powder collector <NUM> may include a material other than the metal.

The metal is not limited in particular, and can be appropriately selected according to the purpose, and examples thereof include stainless steel and the like from the viewpoint of hardness.

The three-dimensional object fabrication apparatus preferably further includes the powder collector <NUM> and another powder collector <NUM> in front of and behind the powder supplier <NUM> in the sub-scanning direction of the powder supplier <NUM>.

Examples of the three-dimensional object fabrication method and a recoating process by the three-dimensional object fabricating apparatus in the present disclosure will be described with reference to <FIG>.

Referring to <FIG>, a mode in which powder is supplied to the fabrication chamber <NUM> at the time of one-way movement in one direction in the reciprocating operation of the recoating unit <NUM> (hereinafter, also referred to as flattener <NUM>) will be described.

For example, in the reciprocating operation of the recoating unit, the advantageous effect of the present disclosure can be sufficiently exhibited even in a mode in which the powder is supplied in a reciprocating manner, by preparing a plurality of recoating units.

<FIG> are cross-sectional views of the recoating unit corresponding to the passage of the entire time during which the recoating unit moves from the back side to the front side of the plane of the drawing. <FIG> illustrates an initial state of the cross section of the fabrication chamber at the start, <FIG> illustrates a state immediately before the recoating unit passes, <FIG> illustrates a state immediately after the recoating unit has passed, and <FIG> illustrates an end state when the recoating unit has completely moved from the back side to the front side of the plane of the drawing.

As illustrated in <FIG>, the fabrication stage <NUM> and a layered surface <NUM> thereon are lowered in height in order to avoid contact with the flattener <NUM>.

<FIG> is a state immediately before the powder collector <NUM> passes and moves powder <NUM> on a top plate <NUM> of the three-dimensional fabricating apparatus of the present disclosure.

<FIG> is a state immediately after the powder collector <NUM> has passed and moved the powder <NUM> on the top plate <NUM> of the three-dimensional fabricating apparatus. As a result, with the movement of the recoating unit, the powder <NUM> on the top plate becomes powder <NUM> having been moved into the fabrication chamber.

<FIG> illustrates an end state when the recoating unit has moved from the back side to the front side of the plane of the drawing.

<FIG> are cross-sectional views of the recoating unit corresponding to the passage of the entire time during which the recoating unit moves from the back side to the front side of the plane of the drawing. <FIG> illustrates an initial state of the cross section of the fabrication chamber at the start, <FIG> illustrates a state immediately before the recoating unit passes, <FIG> illustrates a state in which the powder <NUM> on the layered surface is flattened by the flattener <NUM>, <FIG> illustrates a state immediately after the recoating unit has passed, and <FIG> illustrates an end state when the recoating unit has completely moved from the back side to the front side of the plane of the drawing.

As illustrated in <FIG>, the fabrication stage <NUM> and the layered surface <NUM> thereon are positioned at a designated height to obtain a desired layering step.

<FIG> illustrates powder <NUM> in a state in which the powder <NUM> is layered on the layered surface by the powder supplier <NUM>. At this time, the powder <NUM> on the layered surface has a sufficient amount of powder to be leveled by the flattener <NUM>. In the present embodiment, the powder is supplied from above the layered surface by the powder supplier <NUM>, but the powder supply mode is not limited in particular as long as the powder is supplied to the layered surface.

As illustrated in <FIG>, a part of the powder caught in the flattener flows to the outside of the flattener. The powder is finally accumulated as powder <NUM> outside the powder collector <NUM>.

As illustrated in <FIG>, immediately after passage of the recoating unit, a layered surface <NUM> is generated by the flattener.

As illustrated in <FIG>, the accumulated powder <NUM> disintegrates while having a repose angle according to powder characteristics, and becomes powder <NUM>' in an equilibrium state.

Claim 1:
A method of fabricating a three-dimensional object, the method comprising:
supplying, with a powder supplier (<NUM>), powder to a fabrication chamber (<NUM>), the fabrication chamber (<NUM>) including a fabrication stage (11a) to store powder and an outer edge portion (11b) outside the fabrication stage, the outer edge portion (11b) having one bottom surface;
flattening, with a flattener (<NUM>), the powder supplied by the supplying; and
collecting, with a powder collector (<NUM>), the powder having overflowed from the fabrication stage (11a) to the outer edge portion by the flattening into the fabrication stage.