WO2013137283A1

WO2013137283A1 - Production method for three-dimensionally shaped object, and three-dimensionally shaped object

Info

Publication number: WO2013137283A1
Application number: PCT/JP2013/056879
Authority: WO
Inventors: 不破　勲; 阿部　諭; 東　喜万; 吉田　徳雄; 内野々　良幸; 武南　正孝; 武松本
Original assignee: パナソニック株式会社
Priority date: 2012-03-16
Filing date: 2013-03-06
Publication date: 2013-09-19
Also published as: JPWO2013137283A1

Abstract

Provided is a method for suitably removing attached powder from "an arbitrarily three-dimensionally arranged fluid path" obtained using selective laser sintering. This method for producing a three-dimensionally shaped object repeatedly performs powder-layer formation and solidified-layer formation, by performing: a step (i) in which a light beam is irradiated on a prescribed location on a powder layer, the powder at the prescribed location is sintered or is melted and solidified, and a solidified layer is formed; and a step (ii) in which a new powder layer is formed upon the obtained solidified layer, the light beam is irradiated on a prescribed location on the new powder layer, and another solidified layer is formed. In steps (i) and (ii), a local area corresponding to part of the internal area of the three-dimensionally shaped object is left as a section in a powder state, and a fluid path is formed inside the shaped object by ultimately removing the powder from this section in a powder state. After the shaped object is obtained, the fluid path is polished by causing a fluid comprising a polishing agent to flow as a turbulent flow inside the fluid path.

Description

Manufacturing method of three-dimensional shaped object and three-dimensional shaped object

The present invention relates to a method for manufacturing a three-dimensional shaped object. More specifically, the present invention manufactures a three-dimensional shaped object in which a plurality of solidified layers are laminated and integrated by repeatedly performing formation of a solidified layer by irradiating a predetermined portion of the powder layer with a light beam. In addition to the method, the present invention also relates to a three-dimensional shaped object obtained thereby.

Conventionally, a method of manufacturing a three-dimensional shaped object by irradiating a powder material with a light beam (generally referred to as “powder sintering lamination method”) is known. In such a method, “(i) by irradiating a predetermined portion of the powder layer with a light beam, the powder at the predetermined portion is sintered or melt-solidified to form a solidified layer, and (ii) of the obtained solidified layer A three-dimensional shaped article is manufactured by repeating the process of “laying a new powder layer on the top and irradiating the same with a light beam to form a solidified layer” (see Patent Document 1 or Patent Document 2). When an inorganic powder material such as a metal powder or a ceramic powder is used as the powder material, the obtained three-dimensional shaped object can be used as a mold. On the other hand, when an organic powder material such as resin powder or plastic powder is used, the obtained three-dimensional shaped object can be used as a model. According to such a manufacturing technique, it is possible to manufacture a complicated three-dimensional shaped object in a short time.

Suppose that metal powder is used as a powder material and the obtained three-dimensional shaped object is used as a mold. As shown in FIG. 1, first, a powder layer 22 having a predetermined thickness t1 is formed on a modeling plate 21 (see FIG. 1A), and then a light beam is irradiated on a predetermined portion of the powder layer 22 to form a model. A solidified layer 24 is formed on the plate 21. Then, a new powder layer 22 is laid on the formed solidified layer 24 and irradiated again with a light beam to form a new solidified layer. When the solidified layer is repeatedly formed in this way, a three-dimensional shaped object in which a plurality of solidified layers 24 are laminated and integrated can be obtained (see FIG. 1B). Since the solidified layer corresponding to the lowermost layer can be formed in a state of being adhered to the modeling plate surface, the three-dimensional modeled object and the modeling plate are integrated with each other. The integrated three-dimensional shaped object and the modeling plate can be used as a mold as they are.

JP-T-1-502890 JP 2000-73108 A

The inventors of the present application have found that a unique problem may occur in the powder sintering lamination method as described above (that is, the additive manufacturing method using a light beam). Specifically, it has been found that the following problems occur.

One of the features of the powder sintering lamination method is that a fluid path having an arbitrary shape (arbitrary overall shape and cross-sectional shape) can be arranged inside the three-dimensional shaped structure (the shaped object is used as a plastic mold). In this case, the fluid path can be used as a water pipe for temperature adjustment). For example, assuming a case where a water pipe having a circular cross-sectional shape is arranged inside a modeled object, a portion corresponding to the circular portion may not be irradiated with a light beam. Since the powder remains in the local part where the light beam is not irradiated, a cavity is formed when the powder is removed after shaping. Therefore, the cavity can be used as a fluid path, that is, as a water pipe. However, in such a powder sinter lamination method, unmelted powder adheres around the melting point, so even if a fluid path is produced, the path inner diameter and path cross-sectional area become smaller than intended. (See FIGS. 19 and 20). As a result, it has been found that the amount of water that can be flowed into the fluid path of the modeled object is reduced, resulting in a problem that the temperature controllability is lowered. In addition, a mold-molded article having attached powder on the wall surface (fluid path forming surface) of the temperature adjusting water pipe is stored after removing water from the water pipe after use. It cannot be completely removed. Therefore, it has been found that there is a problem that the corrosion inside the water pipe proceeds due to the residual moisture.

Although it is desirable to remove the adhering powder, it is not easy to remove the powder adhering to the fluid path inside the modeled article. Although straight pipes can be implemented by machining or electrical machining, it is difficult to carry out “arbitrary three-dimensionally arranged water pipes” that are characteristic of the powder sintering lamination method. Furthermore, if the water tube has a circular cross-sectional shape, the attached powder can be removed by cutting the “lower half surface that is not overhanging” in the middle of modeling. It is difficult to cut and remove the upper half surface "due to a steric hindrance (see FIG. 21).

The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a technique for suitably removing the adhered powder from the “fluid path arbitrarily arranged in three dimensions” obtained by the powder sintering lamination method.

In order to solve the above problems, in the present invention,
(I) a step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer; and (ii) a new powder on the obtained solidified layer This is a method for producing a three-dimensional shaped object including a step of forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer, and repeating the step (ii). And
In the steps (i) and (ii), by leaving a local region corresponding to a part of the internal region of the three-dimensional shaped object as a powder state portion, and finally removing the powder in the powder state portion, Form a fluid path inside the 3D shaped object,
After the three-dimensional shaped object is obtained, a method for producing a three-dimensional shaped object is provided in which a fluid path is ground by flowing a fluid containing an abrasive as a turbulent flow in the fluid path.

As a preferable aspect, in steps (i) and (ii), the fluid path is formed so that the diameter dimension of the fluid path changes regularly or irregularly. Turbulent flow is generated in the fluid path by “regular changes”.

As a preferred embodiment, in the steps (i) and (ii), a protrusion or recess is formed on the path forming surface of the fluid path, and in the polishing process, the protrusion is formed in the fluid path due to the protrusion or recess. A turbulent flow may be generated.

Prior to the polishing treatment, an internal member, in particular, an “internal member that generates a turbulent flow with a fluid flow” may be provided in the fluid path. Further, in the steps (i) and (ii), at least a part of the entire form of the fluid path (extension form / extension form of the path) may be configured to generate turbulent flow.

In a preferred embodiment, abrasive particles that can be magnetized are used as the abrasive, and in the polishing process, the abrasive particles are temporarily shifted to the path forming surface of the fluid path (or are concentrated on the path forming surface); The abrasive particles are magnetized so that

Prior to the polishing treatment, the powder remaining on the path forming surface of the fluid path may be corroded. Moreover, you may perform operation which rotates a three-dimensional shape molded article in the case of a grinding | polishing process.

As the abrasive used in the polishing treatment, for example, a granular material (abrasive particles) having a particle diameter of 150 μm to 300 μm is preferably used. The concentration of the abrasive used in the polishing process is preferably 3 vol% to 20 vol%. Note that the fluid itself of the medium containing the abrasive may be water, for example.

In the present invention, a three-dimensional shaped article obtained by the above-described manufacturing method is also provided. The three-dimensional shaped object according to the present invention is characterized by having a fluid path therein, and the flow path forming surface of the fluid path forms a polished surface.

In the present invention, even if the fluid path is arbitrarily three-dimensionally arranged inside the modeled object, at least a part of the path surface (path forming surface) can be polished more cleanly. In particular, in the present invention, even if the fluid path is three-dimensionally curved, at least a part of the path surface can be improved to a substantially uniformly polished surface. Here, as a result of intensive studies by the inventors of the present application, it has been found that a portion that can be polished cleanly and a portion that is not cleanly appear due to a difference in fluid velocity only by flowing an abrasive fluid. 22). Therefore, the present invention preferably utilizes "abrasive fluid turbulence", thereby reducing polishing unevenness and substantially evenly polishing the fluid path inner surface. In other words, according to the present invention, even if the fluid path is “largely or complicatedly curved”, the difference between the portion that can be cleaned and the portion that cannot be cleaned can be reduced.

Since the present invention can polish the path surface of the fluid path substantially more uniformly, even if the fluid path has a narrow shape (even if it corresponds to a water pipe diameter with a small flow path diameter) When using an object as a mold, it is possible to secure a larger amount of temperature-controlled water. Further, the fact that the polishing process can be performed more uniformly means that there is substantially no residual powder on the path surface. Therefore, the residual moisture remaining after using the fluid path as a water pipe (eg, a mold cooling water pipe) is reduced. That is, in the present invention, it is possible to preferably avoid the inconvenience such as “water remains in the adhered powder portion after the mold is used and corrosion proceeds”.

Furthermore, in the case where the polishing process is performed by mechanical processing or electrical processing, it is necessary to previously divide the modeled object by cutting or the like, but in the present invention, the polishing process is performed by a simple operation such as flowing the abrasive fluid in turbulent flow. Can be implemented. And, "regular or irregular changes in the diameter of the fluid path" that contribute to the generation of turbulence, "projection or concave part of the path forming surface" and "the overall extending form of the fluid path", etc. Can be easily and arbitrarily obtained in the powder sintering lamination method. Therefore, in the present invention, a more uniform polishing process can be more efficiently performed without significantly increasing the manufacturing time and manufacturing cost.

Sectional view schematically showing the operation of the stereolithography combined processing machine FIG. 2A is a perspective view schematically showing a mode in which the powder sintering lamination method is performed (FIG. 2A: a composite apparatus including a cutting mechanism, FIG. 2B: an apparatus not including a cutting mechanism). The perspective view which showed typically the structure of the optical shaping complex processing machine by which a powder sintering lamination method is implemented The perspective view which showed typically the aspect by which the powder sintering lamination method is performed Flow chart of operation of stereolithography combined processing machine Schematic representation of the optical modeling complex processing process over time Schematic diagram showing "polishing process using turbulent flow" according to the present invention Schematic diagram showing a mode in which turbulent flow is formed only in the curved portion of the fluid path / downstream portion of the corner portion Schematic diagram showing a mode of generating turbulence by forming the diameter of the fluid path to change regularly. Schematic diagram showing a mode of generating turbulent flow by irregularly changing the diameter of the fluid path Schematic diagram showing a thickened fluid path that is thought to be particularly difficult to flow abrasive fluid Schematic diagram showing a mode of generating turbulent flow by forming protrusions on the path forming surface of the fluid path Schematic diagram showing a mode of generating turbulent flow by forming a concave portion on the path forming surface of the fluid path Schematic diagram showing the mode of generating turbulent flow by providing an internal member in the fluid path Schematic diagram showing an embodiment in which turbulent flow is generated in at least a part of the overall form of the fluid path Schematic diagram showing an aspect of performing an operation of rotating a three-dimensional shaped object when flowing an abrasive fluid Schematic diagram showing an aspect in which the abrasive particles are magnetized so that the abrasive particles are temporarily shifted to the path forming surface of the fluid path. The figure which shows the concept of arithmetic mean roughness (Ra) typically Schematic cross-sectional view and photograph showing an aspect where the adhering powder is present in the fluid path and the path diameter and cross-sectional area are reduced Schematic diagram showing a mode in which the adhering powder exists on the path forming surface of the fluid path Schematic showing that it is difficult to remove the overhang part by cutting Schematic diagram showing a mode in which `` locations that can be polished more neatly '' and `` locations that are not so '' occur due to differences in fluid velocity by simply flowing an abrasive fluid

Hereinafter, the present invention will be described in more detail with reference to the drawings (the dimensional relationships in the drawings are merely examples and do not reflect actual dimensional relationships).

In this specification, “powder layer” refers to, for example, “a metal powder layer made of metal powder” or “a resin powder layer made of resin powder”. The “predetermined portion of the powder layer” substantially means a region of the three-dimensional shaped article to be manufactured. Therefore, by irradiating the powder existing at the predetermined location with a light beam, the powder is sintered or melted and solidified to form the shape of the three-dimensional shaped object. Further, the “solidified layer” substantially means “sintered layer” when the powder layer is a metal powder layer, and substantially means “cured layer” when the powder layer is a resin powder layer. Meaning. The “local region (which is not irradiated with the light beam)” substantially refers to the “powder layer region corresponding to the fluid path” of the manufactured three-dimensional shaped object.

The metal powder that can be used in the present invention is merely a powder mainly composed of iron-based powder, and may be nickel powder, nickel-based alloy powder, copper powder, copper-based alloy powder, and graphite. It may be a powder further comprising at least one selected from the group consisting of powder and the like. As an example, the amount of iron-based powder having an average particle size of about 20 μm is 60 to 90% by weight, the amount of nickel powder and / or nickel-based alloy powder is 5 to 35% by weight, copper powder and / or Examples thereof include metal powders in which the amount of both or any one of the copper-based alloy powders is 5 to 15% by weight and the amount of the graphite powder is 0.2 to 0.8% by weight.

[Powder sintering lamination method]
First, the powder sintering lamination method as a premise of the production method of the present invention will be described. For convenience of explanation, the powder sintering lamination method will be described on the premise that the material powder is supplied from the material powder tank and the powder material is formed by leveling the material powder using a squeezing blade. Further, in the case of the powder sinter lamination method, a description will be given by taking as an example a mode of composite processing in which cutting of a molded article is also performed (that is, assuming the mode shown in FIG. 2A instead of FIG. 2B) And). 1, 3 and 4 show the function and configuration of an optical modeling composite processing machine capable of performing the powder sintering lamination method and cutting. The optical modeling composite processing machine 1 includes “a powder layer forming means 2 for forming a powder layer by spreading a powder such as a metal powder and a resin powder with a predetermined thickness” and “in a modeling tank 29 whose outer periphery is surrounded by a wall 27. In FIG. 2, “a modeling table 20 that moves up and down”, “a modeling plate 21 that is arranged on the modeling table 20 and serves as a foundation of the modeling object”, “a light beam irradiation means 3 that irradiates a light beam L to an arbitrary position”, and “a modeling object” Cutting means 4 ”for cutting the periphery of the main body. As shown in FIG. 1, the powder layer forming means 2 includes “a powder table 25 that moves up and down in a material powder tank 28 whose outer periphery is surrounded by a wall 26” and “to form a powder layer 22 on a modeling plate”. The squeezing blade 23 ". As shown in FIGS. 3 and 4, the light beam irradiation means 3 includes a “light beam oscillator 30 that emits a light beam L” and a “galvanomirror 31 that scans (scans) the light beam L onto the powder layer 22 (scanning). Optical system) ”. If necessary, the light beam irradiation means 3 has beam shape correction means (for example, a pair of cylindrical lenses and a rotation drive mechanism for rotating the lenses around the axis of the light beam) for correcting the shape of the light beam spot. And an fθ lens. The cutting means 4 mainly includes “a milling head 40 that cuts the periphery of the modeled object” and “an XY drive mechanism 41 (41a, 41b) that moves the milling head 40 to a cutting position” (FIGS. 3 and FIG. 3). 4).

The operation of the stereolithography combined processing machine 1 will be described in detail with reference to FIGS. 1, 5, and 6. FIG. FIG. 5 shows a general operation flow of the stereolithography combined processing machine, and FIG. 6 schematically shows the stereolithography combined processing process schematically.

The operation of the optical modeling composite processing machine includes a powder layer forming step (S1) for forming the powder layer 22, a solidified layer forming step (S2) for forming the solidified layer 24 by irradiating the powder layer 22 with the light beam L, It is mainly composed of a cutting step (S3) for cutting the surface of the modeled object. In the powder layer forming step (S1), the modeling table 20 is first lowered by Δt1 (S11). Next, the powder table 25 is raised by Δt1. Then, as shown in FIG. 1A, the squeezing blade 23 is moved in the direction of the arrow A, and the powder arranged on the powder table 25 is transferred onto the modeling plate 21 (S12), while being predetermined. The powder layer 22 is formed to be equal to the thickness Δt1 (S13). Next, the process proceeds to the solidified layer forming step (S2). In the solidified layer forming step (S2), a light beam L (for example, a carbon dioxide laser (about 500 W), an Nd: YAG laser (about 500 W), a fiber laser (about 500 W), or an ultraviolet ray) is emitted from the light beam oscillator 30 (S21). The light beam L is scanned to an arbitrary position on the powder layer 22 by the galvanometer mirror 31 (S22), and the powder is melted and solidified to form a solidified layer 24 integrated with the modeling plate 21 (S23). The light beam is not limited to being transmitted in the air, but may be transmitted by an optical fiber or the like.

The powder layer forming step (S1) and the solidified layer forming step (S2) are repeated until the thickness of the solidified layer 24 reaches a predetermined thickness obtained from the tool length of the milling head 40, and the solidified layer 24 is laminated (FIG. 1). (See (b)). In addition, the solidified layer newly laminated | stacked will be integrated with the solidified layer which comprises the already formed lower layer in the case of sintering or melt-solidification.

When the thickness of the laminated solidified layer 24 reaches a predetermined thickness, the process proceeds to the cutting step (S3). In the embodiment shown in FIGS. 1 and 6, the cutting step is started by driving the milling head 40 (S31). For example, when the tool (ball end mill) of the milling head 40 has a diameter of 1 mm and an effective blade length of 3 mm, a cutting process of a depth of 3 mm can be performed. Therefore, if Δt1 is 0.05 mm, 60 solidified layers are formed. At that time, the milling head 40 is driven. The milling head 40 is moved in the directions of the arrow X and the arrow Y by the XY drive mechanism 41 (41a, 41b), and the surface of the modeled object composed of the laminated solidified layer 24 is cut (S32). And when manufacture of a three-dimensional shape molded article has not ended yet, it will return to a powder layer formation step (S1). Thereafter, the three-dimensional shaped object is manufactured by repeating S1 to S3 and laminating a further solidified layer 24 (see FIG. 6).

The irradiation path of the light beam L in the solidified layer forming step (S2) and the cutting path in the cutting step (S3) are created in advance from three-dimensional CAD data. At this time, a machining path is determined by applying contour line machining. For example, in the solidified layer forming step (S2), contour shape data of each cross section obtained by slicing STL data generated from a three-dimensional CAD model at an equal pitch (for example, 0.05 mm pitch when Δt1 is 0.05 mm) is used. .

[Production method of the present invention]
The present invention is characterized in the processing mode of a shaped article obtained by the above-described powder sintering lamination method. Specifically, as shown in FIG. 7, the polishing process of the fluid path is performed by flowing “fluid containing an abrasive” as a turbulent flow to the fluid path formed inside the three-dimensional shaped object. Do.

The fluid path (which can correspond to a “water pipe” in the case of using a modeled object for a mold) is formed in the process of layered modeling of a three-dimensional modeled object. Specifically, a local area corresponding to a part of the internal area of the three-dimensional shaped object is left as a “powder state portion not irradiated with a light beam”. When the powder in the powder state portion is removed after shaping or after the solidified layer is formed, a fluid path can be formed. Since such a fluid path is formed by a powder sintering lamination method, an overall shape, a cross-sectional shape, and the like can be arbitrarily obtained. However, the powder that did not contribute to the formation of the object is attached to the “fluid path forming surface (surface that forms the fluid path)” (that is, “unsintered powder” is attached to the fluid path surface). is doing). Therefore, in the present invention, in order to remove such adhering powder, a polishing process is performed by flowing a fluid containing an abrasive as a turbulent flow in the fluid path (hereinafter referred to as “comprising an abrasive”). "Fluid" is also referred to as "abrasive fluid" or simply "fluid").

In this specification, “turbulent flow” means a flow with irregular fluctuations in time or space. Such “turbulent flow” means a flow that has been intentionally acted on from the outside and added the irregular fluctuations (see the lower detailed view of FIG. 7). . In other words, according to the present invention, the abrasive fluid is not simply caused to flow in the fluid path, but is intentionally subjected to additional operation / addition means for the fluid flow so that a turbulent flow is obtained.

“Turbulence” does not have to occur in the entire region of the fluid path. It is sufficient that a turbulent flow is generated at least with respect to a region where a portion that can be polished more finely and a portion that cannot be polished more simply by flowing the abrasive fluid through the fluid path. For example, when the fluid path is curved, as shown in FIG. 8, it is sufficient that turbulent flow is formed at least in the curved region and / or in the vicinity thereof, particularly in the downstream region of the channel corner portion.

Turbulence can be generated in the abrasive fluid in various ways. For example, as shown in FIGS. 9 and 10, the diameter of the fluid path 80 is formed so as to change regularly or irregularly (portion “85” shown in the figure), and the rule of such diameter is set. A turbulent flow may be generated in the abrasive fluid by a periodic or irregular change 85. That is, when the abrasive fluid flows through the fluid path 80, turbulence may be generated in the abrasive fluid due to the interaction between the flow and the "regular or irregular change portion 85 of the radial dimension". . In other words, the abrasive fluid flows while interfering with the “regular or irregular change portion 85 of the radial dimension”, and turbulence is generated in the abrasive fluid with the interference.

Such a “regular or irregular change portion 85 of the diameter dimension” can be formed in the powder sintering lamination method. That is, a portion of the powder layer is irradiated with a light beam, and the irradiated portion is sintered or melted and solidified to form a “regular or irregular change portion 85 of the diameter of the fluid path 80”. . This means that the changed portion 85 is integrally obtained from the same material as the modeled object. The form of the change portion 85 is not particularly limited. For example, the path inner surface may change in a curved manner (see FIG. 9), or may change in a non-curve manner.

The “regular or irregular change portion 85 of the diameter dimension of the fluid path 80” does not necessarily have to be formed in the entire region of the flow path forming surface. For example, “regular or irregular change portion 85 of the diameter and size of the fluid path 80” is added to “an area where a portion that can be polished more finely by simply flowing an abrasive fluid into the fluid path and a portion where the abrasive fluid does not flow out”. It is preferable to form it. For example, when the fluid path is curved, the “changed portion 85” may be provided only in the curved region and / or the vicinity thereof (particularly “the downstream region of the flow path corner portion”) (see FIG. 8). ).

As for the degree of diameter change of the fluid path 80, the difference between the minimum diameter dimension _{D min} and a maximum diameter _{D max _(D max} _{-D min)} is the average diameter of the pathway when the _{_{D ave,} D ave} / 10 It is preferably about 3D _ave / 10. Moreover, when an "" regular "change portion 85 ', the pitch _{P A} of the change is, for example, preferably about _{2D _ave} ~ _10D _ave (see FIG. 9).

Regarding changes in the diameter of the fluid path 80, as shown in FIG. 11, particularly the locations where the abrasive fluid is considered to be difficult to flow (for example, the portion where the “adhered powder” is considered to be particularly large or the corner portion). The fluid path may be thickened. This helps to polish the inner surface of the fluid path more evenly even if the fluid path is arbitrarily arranged three-dimensionally. In other words, it is possible to eliminate the difference between a place where polishing can be performed more efficiently and a place where polishing is not possible.

The turbulent flow may be generated by a protruding portion or a concave portion. For example, as shown in FIGS. 12 and 13, a protrusion 94 or a concave portion 96 is formed on the path forming surface of the fluid path 80, and the protrusion 94 or the concave portion 96 causes a turbulent flow to the abrasive fluid. May be generated. In other words, when the abrasive fluid flows through the fluid path 80, turbulent flow may be generated in the abrasive fluid due to the interaction between the flow and the protrusion 94 or the concave portion 96. In other words, the abrasive fluid flows while interfering with the protrusions 94 or the concave portions 96, and turbulence is generated in the abrasive fluid along with the interference.

The protruding portion 94 or the recessed portion 96 can also be formed during the powder sintering lamination method as described above. The cross-sectional shape of the protruding portion 94 or the recessed portion 96 is not particularly limited. For example, the cross-sectional shape of the protruding portion 94 or the concave portion 96 may be a semicircular shape, a rectangular shape, a square shape, a triangular shape, or the like. Further, the protruding portion 94 or the recessed portion 96 is not necessarily formed in the entire region of the flow path forming surface. For example, it is preferable to form the projecting portion 94 or the recessed portion 96 in “a region where a portion that can be polished more finely and a portion that cannot be polished by simply flowing the abrasive fluid through the fluid path”. In the case where the fluid path is curved, the protruding portion 94 or the concave portion 96 may be provided only in the curved region and / or in the vicinity thereof (particularly, the “downstream region of the channel corner portion”) (see FIG. 8).

The dimension of the protrusion height of the protrusion 94 or the depth of the recess 96 is preferably about D / 10 to 3D / 10, where D is the path diameter. Further, the “pitch P _B of the protrusion 94” or the “bitch P _C of the recess 96” is preferably about 1D to 5D, for example (see FIGS. 12 and 13).

The turbulent flow may be generated by using an internal member 98. That is, a member that generates a turbulent flow when the abrasive fluid is flown may be inserted into the fluid path. As shown in FIG. 14, when the abrasive fluid passes through the internal member 98, the flow of the abrasive fluid is affected due to the three-dimensional form of the internal member 98. As a result, the polishing fluid is polished. Turbulent flow is generated in the agent fluid. In other words, the abrasive fluid flows while interfering with the internal member 98 installed in the fluid path, thereby generating a turbulent flow in the abrasive fluid.

The form of the internal member 98 is not particularly limited as long as turbulent flow is generated, and various forms may be adopted. For example, the internal member 98 may have a plate shape as shown in FIG. Further, as shown in FIG. 14B, the internal member 98 may have a form in which a plurality of plate members are connected to each other at an angle.

The internal member 98 may be provided not only in a fixed state but also in a rotatable state. In such a case, the turbulent flow is generated as the internal member 98 rotates. In other words, when the fluid containing the abrasive is flowed, the insertion member may be rotated so that turbulent flow is generated. In other words, the internal member 98 may be rotated by receiving the flow of the abrasive fluid, thereby generating a turbulent flow. Alternatively, the internal member 98 may be forced to rotate by applying an external force to the internal member 98, and turbulence may be generated by such forced rotation of the internal member.

As in the above-described embodiment, the internal member 98 is not necessarily provided in the entire region in the fluid path. It is only necessary that the internal member 98 be provided at least in “a region where a portion that can be polished more finely by simply flowing the abrasive fluid through the fluid path and a portion where the abrasive fluid does not flow out”. For example, when the fluid path is curved, the internal member 98 may be provided only in the curved region and / or the vicinity thereof, for example, the “downstream region of the channel corner” (see FIG. 8). . The internal member 98 can be provided by appropriately removing the “local powder state portion that is not irradiated with the light beam” in the process of laminating the solidified layer and disposing the internal member in the removed portion.

In the present invention, at least a part of the entire form of the fluid path (that is, the overall shape of the path itself) may be configured to generate turbulence. In other words, the diametrical dimension of the fluid path is not particularly changed, but the overall extension of the fluid path may be changed, thereby generating turbulent flow. In particular, it is preferable to have regular or irregular changes to the extended form of the fluid path. For example, as shown in FIG. 15, the overall configuration of the fluid path 80 may be a spiral configuration. In other words, the overall shape of the fluid path 80 may have a spiral shape, a spiral shape, a helical shape, or the like. Helical pitch P _D of the fluid path of such spiral forms, for example, preferably approximately 1D ~ 5D (see Figure 15).

In the present invention, the three-dimensional shaped object may be rotated in order to generate turbulent flow. That is, as shown in FIG. 16, an operation of rotating the three-dimensional shaped object 100 may be performed when flowing the abrasive fluid. In such a case, it is preferable that at least a part of the fluid path 80 has a curved shape. Thereby, it becomes easy to generate a turbulent flow suitably at the time of rotation operation. As long as turbulent flow is generated, the rotational speed is not particularly limited. For example, the rotation speed may be about 30 to 300 rpm so that the rotation speed is high.

In the present invention, the polishing treatment may be performed by additionally applying a magnetic field (or magnetic field or magnetism) (in other words, the magnetic field may be additionally applied to the magnetic abrasive particles). Good). In such a case, abrasive particles that can be magnetized as an abrasive are used, and as shown in FIG. 17, the abrasive particles are magnetized in the polishing process, whereby the abrasive particles are temporarily brought or concentrated on the path forming surface of the fluid path. (In other words, a magnetic field is applied to the magnetic abrasive particles, and thereby the abrasive particles may be temporarily brought or concentrated on the path forming surface of the fluid path. ). For example, as the magnetizable abrasive particles, powder particles made of “quenched SKH steel”, “hardenable ceramic powder (NbC)”, or the like may be used. By such treatment, the abrasive particles can be effectively collected in the adhered powder portion. Therefore, even if the fluid path is arbitrarily arranged three-dimensionally, it is helped to polish the inner surface of the fluid path more uniformly. In other words, it is possible to reduce the difference between the places that can be polished more efficiently and the places that are not.

As for the mode of additionally applying a magnetic field, a strong magnetic field may be applied from the outside particularly in a portion where the abrasive fluid is difficult to flow. In other words, in a portion where the amount of adhered powder is particularly large, by applying a strong magnetic field, the abrasive particles are concentrated on the portion, thereby enabling an effective polishing process. After polishing, the abrasive particles that remain magnetized inside the fluid path may be removed by demagnetization. That is, after the polishing, the application of the magnetic field may be stopped as necessary, and “the state where the abrasive particles are brought together / the state where they are concentrated” may be canceled as appropriate.

Prior to the polishing process, a process of corroding the powder remaining on the path forming surface of the fluid path may be performed. Since the residual powder becomes brittle due to corrosion, the polishing treatment can be performed more efficiently. That is, the residual powder that has become brittle due to corrosion is easily removed by the turbulent abrasive fluid. The corrosion treatment may be performed, for example, by flowing an acidic liquid such as sulfuric acid into the fluid path.

研磨 Details of the abrasive fluid. The abrasive fluid used in the present invention is not particularly limited as long as abrasive grains that function as an abrasive (that is, abrasive particles) are contained in the liquid. In such an abrasive fluid, the abrasive grains are present in a dispersed / free state in the liquid. In view of this point, it can be said that the present invention performs the polishing process of the fluid path by supplying loose abrasive grains as a turbulent flow into the fluid path.

The abrasive itself is, for example, a granular material (that is, abrasive particles) having a particle size (particularly an average particle size) of preferably 150 μm to 300 μm, more preferably 200 μm to 250 μm. Use of an abrasive having such a particle size is particularly desirable for removal of adhered powder (i.e., removal by the abrasive action of the abrasive fluid). The “average particle size” as used in the present specification refers to, for example, the particle size of 300 particles measured based on an electron micrograph or an optical micrograph of a granular material (that is, abrasive particles), and calculated as the number average. ("Particle size" substantially refers to the maximum length among the lengths in any direction of the particles).

The material of the abrasive is preferably ceramic or metal. For example, the abrasive may be made of at least one material selected from the group consisting of alumina, diamond, boron nitride, zirconia, and silicon carbide.

The medium liquid for dispersing and releasing the abrasive may be water, for example. Use of water is not only advantageous in terms of cost but also has an appropriate fluidity at room temperature, so that the abrasive can be suitably dispersed and released.

The concentration of the abrasive in the fluid used for the polishing treatment is preferably about 3 vol% to 20 vol%, more preferably about 4 vol% to 15 vol%, and still more preferably about 5 vol% to 10 vol% (abrasive fluid) Of total volume).

[Three-dimensional shaped object of the present invention]
Next, the three-dimensional shaped object of the present invention obtained by the above manufacturing method will be described. The three-dimensional shaped article of the present invention can be used as a plastic mold or mold part. Here, the three-dimensional shaped object according to the present invention is characterized by having a fluid path therein, and the flow path forming surface of the fluid path forms a polished surface. For example, regarding the roughness of the polished surface, the surface roughness Ra is preferably 5 μm to 25 μm, more preferably 5 μm to 20 μm. The “arithmetic average roughness (Ra)” in the present specification refers to the direction of the average line from a roughness curve as shown in FIG. 18 (in the present invention, “cross-sectional profile of the flow path forming surface”). The reference length L is extracted, and the value obtained by summing the absolute values of deviations from the average line to the measurement curve in this extracted portion is substantially meant.

As mentioned above, although embodiment of this invention has been described, it has only illustrated the typical example in the application range of this invention. Therefore, those skilled in the art will readily understand that the present invention is not limited thereto and various modifications can be made.

For example, in the invention, turbulent flow is generated in at least a part of the fluid path. However, the generation location is not limited to the inside of the fluid path, and may be outside the fluid path. For example, prior to introducing the abrasive fluid into the fluid path. A turbulent flow may be generated in the fluid in advance. The means for generating the turbulent flow in advance is not particularly limited, and the above-described “projection-like portion 94 or concave portion 96”, “internal member 98”, or the like may be used. In such an aspect, turbulent flow can be generated simply by providing the attached means after manufacturing the modeled object, so that the polishing process can be performed without affecting the model itself.

In addition, the “projection-like portion 94 or the concave portion 96”, the “internal member 98”, the “means for generating turbulent flow”, etc. are not limited to being used alone, but may be appropriately combined with each other. It does not matter.

Furthermore, in order to generate turbulent flow, fluid may be supplied so as to pulse in a pulse shape. Further, the three-dimensional shaped object may vibrate when flowing the abrasive fluid.

The present invention as described above includes the following aspects:
First aspect : (i) a step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer; and (ii) on the obtained solidified layer Forming a new powder layer, irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer, and repeating the powder layer formation and the solidified layer formation, A manufacturing method comprising:
In the steps (i) and (ii), a local region corresponding to a part of the internal region of the shaped article is left as a powder state portion, and the powder in the powder state portion is finally removed, thereby Form a fluid path inside the model,
A method for producing a three-dimensional shaped object, wherein after the shaped object is obtained, the fluid path is polished by flowing a fluid containing an abrasive as a turbulent flow in the fluid path.
Second aspect : In the first aspect, in the steps (i) and (ii), the fluid path is formed so that the diameter dimension of the fluid path changes regularly or irregularly. The method for producing a three-dimensional shaped object, wherein the turbulent flow is generated in the fluid path due to the regular or irregular change in the diameter.
Third aspect : In the first aspect, in the steps (i) and (ii), a protruding portion or a recessed portion is formed on a path forming surface of the fluid path, and the protruding portion or the The method for producing a three-dimensional shaped object, wherein the turbulent flow is generated in the fluid path due to a concave portion.
Fourth aspect : A three-dimensional shaped object according to any one of the first to third aspects, wherein an internal member that generates the turbulent flow in accordance with the flow of the fluid is provided in the fluid path. Manufacturing method.
Fifth aspect : In any one of the first to fourth aspects, a magnetizable abrasive particle is used as the abrasive, and in the polishing treatment, the abrasive particle is temporarily placed on a path forming surface of the fluid path. A method for producing a three-dimensional shaped article, characterized in that the abrasive particles are magnetized so as to be in a state of approaching.
Sixth aspect : In any one of the first to fifth aspects described above, in steps (i) and (ii), at least a part of the overall form of the fluid path is made into a form in which turbulent flow is generated. A method for producing a three-dimensional shaped object characterized by that.
Seventh aspect : In any one of the first to sixth aspects, the three-dimensional shaped article is produced by corroding the powder remaining on the path forming surface of the fluid path prior to the polishing treatment. Method.
Eighth aspect : The method for producing a three-dimensional shaped article according to any one of the first to seventh aspects, wherein the shaped article is rotated during the polishing process.
Ninth aspect : Production of a three-dimensional shaped object according to any one of the first to eighth aspects, wherein a granular material having a particle size of 150 µm to 300 µm is used as the abrasive used in the polishing treatment. Method.
Tenth aspect : The method for producing a three-dimensional shaped structure according to any one of the first to ninth aspects, wherein the fluid used in the polishing treatment has an abrasive concentration of 3 vol% to 20 vol%.
Eleventh aspect : a three-dimensional shaped article obtained by the manufacturing method according to any one of the first to tenth aspects,
The three-dimensional modeled object has a fluid path therein, and a flow path forming surface of the fluid path forms a polished surface.

Various articles | goods can be manufactured by implementing the manufacturing method of the three-dimensional shape molded article of this invention. For example, in “when the powder layer is an inorganic metal powder layer and the solidified layer is a sintered layer”, the resulting three-dimensional shaped article is a plastic injection mold, a press mold, a die-cast mold, It can be used as a mold such as a casting mold or a forging mold. In addition, in “when the powder layer is an organic resin powder layer and the solidified layer is a cured layer”, the obtained three-dimensional shaped article can be used as a resin molded product.

Cross-reference of related applications

The present application is based on the Paris Convention based on Japanese Patent Application No. 2012-60207 (Application Date: March 16, 2012, Title of Invention: “Manufacturing Method of Three-Dimensional Shaped Model and Three-dimensional Shaped Model”). Claim priority. All the contents disclosed in the application are incorporated herein by this reference.

DESCRIPTION OF SYMBOLS 1 Optical modeling combined processing machine 2 Powder layer formation means 3 Light beam irradiation means 4 Cutting means 19 Powder / powder layer (For example, metal powder / metal powder layer or resin powder / resin powder layer)
20 modeling table 21 modeling plate 22 powder layer (for example, metal powder layer or resin powder layer)
23 Squeezing blade (leveling plate / leveling blade)
24 Solidified layer (for example, sintered layer or hardened layer) or three-dimensional shaped object 25 obtained therefrom Powder table 26 Wall part 27 of powder material tank Wall part 28 of tank for forming material 28 Powder material tank 29 Modeling tank 30 Light beam oscillator 31 Galvano Mirror 32 Reflecting mirror 33 Condensing lens 40 Milling head 41 XY drive mechanism 41a X-axis drive unit 41b Y-axis drive unit 42 Tool magazine 50 Chamber 52 Light transmission window 80 Fluid path (flow path)
85 Regular or irregular changes in the diameter of the fluid path 86 Internal member (path internal insert)
87 Internal member that can be rotated (insert inside the path)
94 Protruding part 96 Concave part 98 Internal member 100 Three-dimensional shaped article (particularly a three-dimensional shaped article having a fluid path)
L Light beam

Claims

(I) irradiating a predetermined portion of the powder layer with a light beam to sinter or melt-solidify the powder at the predetermined portion to form a solidified layer; and (ii) a new powder on the obtained solidified layer. This is a method for producing a three-dimensional modeled object in which a powder layer and a solidified layer are repeatedly formed by a step of forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer. And
In the steps (i) and (ii), a local region corresponding to a part of the internal region of the shaped article is left as a powder state portion, and the powder in the powder state portion is finally removed, thereby Form a fluid path inside the model,
A method for producing a three-dimensional shaped object, wherein after the shaped object is obtained, the fluid path is polished by flowing a fluid containing an abrasive as a turbulent flow in the fluid path.
In the steps (i) and (ii), the fluid path is formed so that the diameter dimension of the fluid path changes regularly or irregularly. In the polishing process, the regular or irregular diameter dimension is determined. The method for producing a three-dimensional shaped object according to claim 1, wherein the turbulent flow is generated in the fluid path due to regular change.
In the steps (i) and (ii), a protruding portion or a recessed portion is formed on the path forming surface of the fluid path, and in the polishing process, the inside of the fluid path is caused by the protruding portion or the recessed portion. The method for producing a three-dimensional shaped article according to claim 1, wherein the turbulent flow is generated.
4. The method for producing a three-dimensional shaped object according to claim 1, wherein an internal member that generates the turbulent flow in accordance with the flow of the fluid is provided in the fluid path.
Abrasive particles that can be magnetized are used as the abrasive, and in the polishing process, the abrasive particles are magnetized so that the abrasive particles are temporarily shifted to a path forming surface of the fluid path. The method for producing a three-dimensional shaped article according to any one of claims 1 to 4, characterized in that it is characteristic.
6. The process according to any one of claims 1 to 5, wherein in the steps (i) and (ii), at least a part of an overall form of the fluid path is formed to generate turbulent flow. A manufacturing method of a three-dimensional shaped object.
The method for producing a three-dimensional shaped article according to any one of claims 1 to 6, wherein the powder remaining on the path forming surface of the fluid path is corroded prior to the polishing treatment.
The method for producing a three-dimensional shaped article according to any one of claims 1 to 7, wherein the shaped article is rotated during the polishing process.
The method for producing a three-dimensional shaped article according to any one of claims 1 to 8, wherein a granular material having a particle size of 150 to 300 µm is used as the abrasive used in the polishing treatment.
10. The method for producing a three-dimensional shaped article according to claim 1, wherein the fluid used in the polishing treatment has an abrasive concentration of 3 vol% to 20 vol%.
A three-dimensional shaped article obtained by the production method according to any one of claims 1 to 10,
The three-dimensional modeled object has a fluid path therein, and a flow path forming surface of the fluid path forms a polished surface.