WO2020218449A1

WO2020218449A1 - Method for manufacturing three-dimensionally shaped molded article, and device for manufacturing three-demonsionally shaped molded article

Info

Publication number: WO2020218449A1
Application number: PCT/JP2020/017562
Authority: WO
Inventors: 武松本; 田中　健一; 裕紀吉永; 阿部　諭
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-04-26
Filing date: 2020-04-23
Publication date: 2020-10-29
Also published as: JP2022096005A

Abstract

An embodiment of the present invention is a method for manufacturing a three-dimensionally shaped molded article by alternately and repeatedly layering a powder layer and a solidification layer, by (i) a step for radiating a light beam to a predetermined portion of a powder layer and sintering or melt-solidifying the powder in the predetermined portion to form a solidification layer, and (ii) a step for forming a new powder layer on the resultant solidification layer and radiating a light beam to a predetermined portion of the new powder layer to form another solidification layer. In particular, in an embodiment of the present invention, a shaping process condition is changed in accordance with the height of a precursor of the three-dimensionally shaped molded article, in the course of manufacturing the three-dimensionally shaped molded article.

Description

Manufacturing method of three-dimensional shaped object and device for manufacturing three-dimensional shaped object

The present invention relates to a method for manufacturing a three-dimensional shaped object and an apparatus for producing a three-dimensional shaped object. More specifically, the present invention relates to a method for producing a three-dimensional shaped object that forms a solidified layer by irradiating a powder layer with a light beam, and an apparatus for producing the three-dimensional shaped object.

A method of producing a three-dimensional shaped object by irradiating a powder material with a light beam (generally referred to as a "powder bed fusion bonding method") has been conventionally known. In such a method, powder layer formation and solidified layer formation are alternately and repeatedly carried out based on the following steps (i) and (ii) to produce a three-dimensional shaped object.
(I) A step of irradiating a predetermined portion of the powder layer with a light beam and sintering or melt-solidifying the powder at the predetermined portion to form a solidified layer.
(Ii) A step of forming a new powder layer on the obtained solidified layer and similarly irradiating with a light beam to form a further solidified layer.

According to such a manufacturing technique, it is possible to manufacture a complicated three-dimensional shaped object in a short time. When an inorganic metal 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 resin powder is used as the powder material, the obtained three-dimensional shaped model can be used as various models.

Take as an example the case where metal powder is used as the powder material and the three-dimensional shaped object obtained by it is used as a mold. As shown in FIG. 11, first, the squeezing blade 23 is moved to form a powder layer 22 having a predetermined thickness on the modeling plate 21 (see FIG. 11A). Next, a predetermined portion of the powder layer 22 is irradiated with a light beam L to form a solidified layer 24 from the powder layer 22 (see FIG. 11B). Subsequently, a new powder layer is formed on the obtained solidified layer and irradiated with a light beam again to form a new solidified layer. When the powder layer formation and the solidification layer formation are alternately and repeatedly performed in this way, the solidification layer 24 is laminated (see FIG. 11C), and finally, the three-dimensional structure composed of the laminated solidification layer 24 is formed. A shaped object can be obtained. Since the solidified layer 24 formed as the lowermost layer is in a state of being bonded to the modeling plate 21, the three-dimensional shaped model and the modeling plate 21 form an integrated product, and the integrated product can be used as a mold.

Japanese Patent No. 6062940 Japanese Patent No. 6254036 JP-A-2017-66023 Japanese Unexamined Patent Publication No. 2004-306612

Here, the production of the three-dimensional shaped object by forming the solidified layer 24'using the light beam L'is performed on the modeling table 20'adjusted to a predetermined constant temperature by the temperature control device 50'. In some cases (see FIG. 14).

In this case, in the precursor 100'of the three-dimensional shaped model having a relatively low height during manufacturing, the distance from the modeling plate 21' located on the temperature-controlled modeling table 20'is relatively short. Due to this, the difference between the upper surface (surface) temperature of the precursor 100'of the three-dimensional shaped object having a relatively low height and the temperature of the modeling plate 21'is small. On the other hand, in the precursor 100'of a three-dimensional shaped object having a relatively high height during manufacturing, the height is relatively low due to the relatively long distance from the modeling plate 21'. There is a large difference between the upper surface (surface) temperature of the precursor 100'of the original shape model and the temperature of the model plate 21'.

In this regard, the inventors of the present application, when the above temperature difference is present, correspond to the expansion of the solidified layer 24', which is a component of the precursor 100' of the three-dimensional shaped model, along the height direction. We have newly found that contraction can occur. In particular, when the temperature difference is large, the solidified layer 24'located on the upper surface side of the precursor 100'of the three-dimensionally shaped model having a relatively high height corresponding to the above-mentioned temperature difference expands or expands along the height direction. It was newly found that the degree of contraction increases. Therefore, due to this, there is a possibility that the height of the precursor 100'of the three-dimensional shaped model in the middle of production after a lapse of a predetermined time after the start of production may not be the desired height. Therefore, the thickness of the new powder layer 22'formed later may change. If the production is continued under the same laser irradiation conditions in this state, for example, the amount of sputtering (sparks) and / or fume (smoke) increases, and the density of the finally obtained three-dimensional shaped object 100A'is increased. Problems such as lowering and more likely to cause pores (vacancy) may occur. As a result, the quality of the finally obtained three-dimensional shaped object 100A'may change. That is, the dimensional accuracy (particularly the height accuracy) of the finally obtained three-dimensional shaped object 100A'may decrease.

The present invention has been made in view of such circumstances. That is, an object of the present invention is a method for manufacturing a three-dimensional shaped object capable of suitably suppressing a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object, and the three-dimensional object. It is to provide a manufacturing apparatus for shaped objects.

In order to achieve the above object, in one embodiment of the present invention,
(I) A step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt and solidify the powder at the predetermined portion to form a solidified layer, and (ii) a new powder on the obtained solidified layer. A three-dimensional shaped product is manufactured by forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer by alternately and repeatedly laminating the powder layer and the solidified layer. How to do
In the middle of the production, a method for producing a three-dimensional shape model is provided, in which the modeling process conditions are changed according to the height of the precursor of the three-dimensional shape model.

In order to achieve the above object, in one embodiment of the present invention,
It is a device for manufacturing three-dimensional shaped objects.
Powder layer forming part,
Light beam irradiation unit for forming a solidified layer from a powder layer,
An arithmetic control unit that can change and control the modeling process conditions during the manufacturing of the three-dimensional shaped object, and
An apparatus provided with at least one of a height measuring unit capable of measuring the height of the precursor of the three-dimensional shape model and a temperature measuring unit capable of measuring the temperature of the upper surface of the precursor of the three-dimensional shape model. Will be done.

According to one embodiment of the present invention, it is possible to suitably suppress a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object.

Schematic diagram for explaining the heat balance in the solidified layer formation stage using an optical beam Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic to illustrate the heat balance during the manufacture of "slender and tall" shaped precursors Schematic to illustrate the heat balance during the manufacture of "large area and short" shaped precursors Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. Schematic diagram showing the manufacturing method of the three-dimensional shaped object which concerns on one Embodiment of this invention. A cross-sectional view schematically showing a process mode of stereolithography composite processing in which the powder bed melt bonding method is carried out (FIG. 11 (a): at the time of forming a powder layer, FIG. 11 (b): at the time of forming a solidified layer, FIG. c): During stacking) Perspective view schematically showing the configuration of the stereolithography compound processing machine Flowchart showing general operation of stereolithography multi-tasking machine Schematic cross-sectional view showing the technical problems of the present application

Hereinafter, one embodiment of the present invention will be described in more detail with reference to the drawings. The forms and dimensions of the various elements in the drawings are merely examples and do not reflect the actual forms and dimensions.

In the present specification, the "powder layer" means, for example, a "metal powder layer made of metal powder" or a "resin powder layer made of resin powder". Further, the “predetermined location of the powder layer” substantially refers to the region of the three-dimensional shaped object to be manufactured. Therefore, by irradiating the powder existing at the predetermined location with a light beam, the powder is sintered or melt-solidified to form a three-dimensional shaped object.

Further, the "up and down" direction described directly or indirectly in the present specification is, for example, a direction based on the positional relationship between the modeling plate and the three-dimensionally shaped object, and is three-dimensional with respect to the modeling plate. The side on which the shaped object is manufactured is referred to as "upward", and the opposite side is referred to as "downward".

[Powder bed melt bonding method]
First, the powder bed melt-bonding method, which is a premise of the production method of the present invention, will be described. In particular, the stereolithography composite processing in which the cutting process of the three-dimensional shaped object is additionally performed in the powder bed fusion bonding method will be given as an example. FIG. 11 schematically shows a process mode of stereolithography composite processing, and FIGS. 12 and 13 are flowcharts of main configurations and operations of a stereolithography composite processing machine capable of performing a powder bed fusion bonding method and a cutting process. Are shown respectively.

As shown in FIG. 12, the stereolithography composite processing machine 1 includes a powder layer forming portion 2, a light beam irradiation portion 3, and a cutting portion 4.

The powder layer forming portion 2 is for forming a powder layer by laying a powder such as a metal powder or a resin powder with a predetermined thickness. The light beam irradiation unit 3 is for irradiating a predetermined portion of the powder layer with the light beam L. The cutting portion 4 is for cutting the surface of the laminated solidified layer, that is, the surface of the three-dimensional shaped object.

As shown in FIG. 11, the powder layer forming portion 2 mainly includes a powder table 25, a squeezing blade 23, a modeling table 20, and a modeling plate 21. The powder table 25 is a table that can be raised and lowered in a powder material tank 28 whose outer circumference is surrounded by a wall 26. The squeezing blade 23 is a blade capable of horizontally moving the powder 19 on the powder table 25 onto the modeling table 20 to obtain the powder layer 22. The modeling table 20 is a table that can be raised and lowered in a modeling tank 29 whose outer circumference is surrounded by a wall 27. The modeling plate 21 is a plate that is arranged on the modeling table 20 and serves as a base for a three-dimensionally shaped object.

As shown in FIG. 12, the light beam irradiation unit 3 mainly includes a light beam oscillator 30 and a galvanometer mirror 31. The optical beam oscillator 30 is a device that emits an optical beam L. The galvanometer mirror 31 is a means for scanning the emitted light beam L on the powder layer 22, that is, a means for scanning the light beam L.

As shown in FIG. 12, the cutting portion 4 mainly includes an end mill 40 and a drive mechanism 41. The end mill 40 is a cutting tool for scraping the surface of a laminated solidified layer, that is, the surface of a three-dimensional shaped object. The drive mechanism 41 moves the end mill 40 to a desired position to be cut.

The operation of the stereolithography compound processing machine 1 will be described in detail. As shown in the flowchart of FIG. 13, the operation of the stereolithography composite processing machine 1 is composed of a powder layer forming step (S1), a solidified layer forming step (S2), and a cutting step (S3). The powder layer forming step (S1) is a step for forming the powder layer 22. In the powder layer forming step (S1), first, the modeling table 20 is lowered by Δt (S11) so that the level difference between the upper surface of the modeling plate 21 and the upper end surface of the modeling tank 29 is Δt. Next, after raising the powder table 25 by Δt, the squeezing blade 23 is moved horizontally from the powder material tank 28 toward the modeling tank 29 as shown in FIG. 11A. As a result, the powder 19 arranged on the powder table 25 can be transferred onto the modeling plate 21 (S12), and the powder layer 22 is formed (S13). Examples of the powder material for forming the powder layer 22 include "metal powder having an average particle size of about 5 μm to 100 μm" and "resin powder such as nylon, polypropylene, or ABS having an average particle size of about 30 μm to 100 μm". it can. After the powder layer 22 is formed, the process proceeds to the solidified layer forming step (S2). The solidified layer forming step (S2) is a step of forming the solidified layer 24 by irradiation with a light beam. In the solidified layer forming step (S2), the light beam L is emitted from the light beam oscillator 30 (S21), and the light beam L is scanned to a predetermined position on the powder layer 22 by the galvanometer mirror 31 (S22). As a result, the powder at a predetermined position in the powder layer 22 is sintered or melt-solidified to form the solidified layer 24 as shown in FIG. 11 (b) (S23). As the light beam L, a carbon dioxide gas laser, an Nd: YAG laser, a fiber laser, ultraviolet rays, or the like may be used.

The powder layer forming step (S1) and the solidified layer forming step (S2) are alternately and repeatedly carried out. As a result, as shown in FIG. 11C, a plurality of solidified layers 24 are laminated.

When the laminated solidified layer 24 reaches a predetermined thickness (S24), the process proceeds to the cutting step (S3). The cutting step (S3) is a step for cutting the surface of the laminated solidified layer 24, that is, the surface of the three-dimensional shaped object. The cutting step is started by driving the end mill 40 (see FIGS. 11C and 12) (S31). For example, when the end mill 40 has an effective blade length of 3 mm, a cutting process of 3 mm can be performed along the height direction of the three-dimensional shaped object. Therefore, if Δt is 0.05 mm, it is equivalent to 60 layers. The end mill 40 is driven when the solidified layers 24 are laminated. Specifically, the surface of the laminated solidified layer 24 is subjected to a cutting process while the end mill 40 is moved by the drive mechanism 41 (S32). At the final stage of such a cutting step (S3), it is determined whether or not a desired three-dimensional shaped object is obtained (S33). If the desired three-dimensional shaped object has not yet been obtained, the process returns to the powder layer forming step (S1). After that, the powder layer forming step (S1) to the cutting step (S3) are repeatedly carried out to further stack the solidified layer and perform the cutting process, whereby a desired three-dimensional shaped object is finally obtained.

[Manufacturing method of the present invention]
Hereinafter, a method for manufacturing a three-dimensional shaped object according to an embodiment of the present invention will be described.

First, before explaining the technical idea of the present invention, the background leading to the idea of the technical idea will be explained (see FIG. 1A).

As described above, in the production of a three-dimensional shaped object by the powder bed fusion bonding method, it may be performed on a modeling table adjusted to a predetermined constant temperature by a temperature adjusting device. The powder bed melt-bonding method can be roughly divided into a desired three-dimensional shape by alternately performing (A) a powder layer forming step and (B) a solidifying layer forming step by irradiating a predetermined portion of the powder layer with a light beam. It is possible to manufacture a modeled object. In this case, the inventors of the present application focused on the heat balance during the implementation of the powder bed fusion bonding method. The contents of such heat balance are as follows (see Table 1 below).

[Table 1] Heat balance at the stage of implementing the powder bed fusion bonding method

As can be seen from the upper part of Table 1 and FIG. 11A, heat input / heating does not occur in the powder layer forming step (A) because no light beam is used. On the other hand, in the step (A) of forming the powder layer, heat dissipation from the surface (specifically, the upper surface) of the modeled precursor, heat conduction inside the modeled precursor, and heat removal by the temperature control device are simultaneously generated.

On the other hand, as can be seen from the lower part of Table 1 and FIG. 1A, since the light beam is used in the step of forming the solidified layer by (B) light beam irradiation, the surface of the modeled precursor 100 (specifically, the upper surface 101). Is heated. In addition to this, in the step (B) of forming the solidified layer, heat is dissipated from the surface (specifically, the upper surface 101) of the model precursor 100, heat conduction inside the model precursor 100, and removal by the temperature control device 50. Heat is generated at the same time.

From the above, focusing on the heat balance, in the (A) powder layer forming process, only heat dissipation and heat removal affect the heat balance. On the other hand, in the (B) solidification layer forming step, heating and heat dissipation / heat removal coexist, and the influence of heat input / heating is greater than that of heat dissipation / heat removal, or heat dissipation is greater than heat input / heating. / There may be cases where the effect of heat removal is greater. Therefore, both heating and heat dissipation / removal affect the heat balance.

Based on these matters, it can be said that the temperature of the modeled precursor 100 can change in the (B) solidified layer forming step in which heat inflow and outflow coexist. In this case, a temperature difference may occur between the temperature of the upper surface of the model precursor 100 and the temperature of the model plate 21 (that is, the base plate 20α) located on the model table 20 adjusted to a constant temperature. In a situation where such a temperature difference occurs (that is, a situation in which the temperature of the precursor 100 can change), as described above, as newly discovered by the inventors of the present application, the precursor 100 of the modeled object 100 Expansion or contraction along the height direction of the solidified layer 24 located on the upper surface side may occur. As a result, the height of the precursor 100X can be higher or lower than the desired height.

From the above, the inventors of the present application will explain in detail below, but the modeling process conditions are not maintained constant during the production of the three-dimensional shape model, but the three-dimensional shape during the production. I have noticed that it is preferable to change it as appropriate according to the height of the precursor 100 of the modeled object. Based on this viewpoint, the inventors of the present application have come up with the present invention having the following technical ideas.

(Technical Idea of the Present Invention)
Specifically, the inventors of the present application have the technical idea that "the modeling process conditions are changed according to the height of the precursor of the three-dimensional shaped object during the production of the three-dimensional shaped object". (See Fig. 1B).

According to such a technical idea, the modeling process conditions are not maintained constant during the production of the 3D shaped object, but depend on the height of the precursor 100 of the 3D shaped object during the production. Will be changed as appropriate. Specifically, instead of making the modeling process conditions continuously constant during the production of the three-dimensionally shaped object, the actual height of the precursor 100 during production is different from the predetermined ideal height. If it is grasped, change the modeling process conditions on the way. By changing the molding process conditions, the actual height of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

The "modeling process conditions" referred to in the present specification are the temperature, flow rate and flow velocity of the temperature control medium contained in the base plate 20α which is the base of the three-dimensional shape model to be manufactured, the temperature of the heat source element, and the thickness of the powder layer 22. Also refers to at least one selected from the group consisting of the irradiation conditions of the light beam L. The "base plate 20α" as used herein is a general term for the modeling table 20 and the modeling plate 21 positioned on the modeling table 20. The "temperature control source 60" as used herein is a general term for a temperature control medium and a heat source element (heater source, etc.). The "upper surface of the precursor 100 of the modeled product" as used herein refers to the surface of the uppermost solidified layer among the laminated solidified layers which are the constituent elements of the precursor 100 of the modeled product in the intermediate stage of manufacturing. Specifically, it refers to the main surface).

In one embodiment of the present invention, the modification of the modeling process conditions is carried out according to the height of the precursor 100 of the modeled product, and the criteria for implementing the change are as follows: (1) During production. It can be divided into a temperature measurement value of the upper surface of the precursor 100 of the modeled object and / or (2) a measured height value of the precursor 100 of the modeled object.

In the following, the criteria for changing the modeling process conditions will be described mainly on the premise that the former is based on the "temperature measurement value of the upper surface of the precursor 100 of the modeled product in the process of manufacturing" (see FIG. 2).

In such a case, the temperature of the upper surface of the precursor 100 when the precursor 100 in the middle of production has a predetermined height is measured by using a temperature sensor 80 or the like. If it is determined that the temperature is different from the top surface temperature of the precursor 100 or the surface temperature of the base plate 20α at a height relatively lower than the predetermined height, the modeling process conditions are changed.

Specifically, when manufacturing a three-dimensional shaped object on a base plate 20α having a temperature control source 60 inside, the above-mentioned modeling process conditions include temperature control flowing through the temperature control pipeline as the temperature control source 60. It may be the temperature, flow rate, and / or flow rate of the medium 61. Further, the modeling process condition may be the temperature of the heat source element as the temperature control source 60. The modeling process conditions are not limited to this, and may be the thickness of the powder layer 22 and the irradiation conditions of the light beam L. Examples of the irradiation conditions of the light beam include the irradiation energy, spot diameter, scanning speed, and the like of the light beam described later. However, the irradiation conditions of the light beam are not limited to these.

● Corresponding pattern for reducing the temperature difference (modeling process conditions: temperature, flow rate, and / or flow velocity of the temperature control medium 61)
Hereinafter, an embodiment in which the temperature, flow rate, and / or flow velocity of the temperature control medium 61 are used as the above-mentioned modeling process conditions will be taken as an example. This aspect, which will be specifically described below, is based on the idea of minimizing the temperature difference (the temperature difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α).

For example, it is one of the modeling process conditions when it is determined that there is a difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α when the precursor 100 in the middle of production has a predetermined height. The temperature, flow rate, and / or flow velocity of the temperature control medium 61 flowing through the temperature control line in the base plate 20α is changed in the middle stage.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 80 or the like is driven to measure the temperature of the upper surface of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. Similarly, the temperature sensor 80 or the like is driven to measure the surface temperature of the base plate 20α. Based on the temperature measurement values of both, the arithmetic control unit 70 determines whether or not there is a difference between the temperature measurement values of both. When it is determined that there is a difference, the temperature control device 50 is driven under the instruction of the arithmetic control unit 70, and the temperature control medium supplied from the temperature control device 50 to the temperature control source 60 (temperature control line). The temperature, flow rate, and / or flow velocity are changed and controlled in the middle.

More specifically, in one embodiment, under the instruction of the arithmetic control unit 70, the temperature from the temperature control device 50 to the temperature control source 60 (temperature control line) is relatively lower or higher than that before the change. The conditioning medium may flow. In one aspect, under the direction of the arithmetic control unit 70, a temperature control medium in which the flow rate is relatively increased or decreased as compared with that before the change is supplied from the temperature control device 50 to the temperature control source 60 (temperature control line). You can let it flow. Further, in one embodiment, under the instruction of the arithmetic control unit 70, a temperature control medium having a relatively high or slow flow velocity as compared with that before the change is flowed from the temperature control device 50 to the temperature control source 60 (temperature control line). You can.

For example, when it is determined that the temperature of the upper surface of the precursor 100 is higher than the surface temperature of the base plate 20α, the temperature is set relatively lower than the medium temperature whose temperature is controlled to be constant at the beginning, and the medium is preferably added to this. Increase the flow rate. In this case, at the time when the change control for lowering the medium temperature is started or in the vicinity thereof, the low region where the height of the model precursor 100 adjacent to the base plate 20α is low can be cooled first. At this point, the cooling action on the high region where the height of the model precursor 100 away from the base plate 20α is high is small. After that, when the change control for lowering the medium temperature is started and a predetermined time elapses, the high region where the height of the modeled precursor 100 away from the base plate 20α is high also begins to be cooled.

Finally, the thermal energy of the temperature control medium 61 can be transmitted to the upper surface region of the precursor 100 having a relatively high height, whereby the temperature of the upper surface region can be lowered. As a result, the temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α can be finally reduced. As a result, even when the height of the precursor 100 of the three-dimensional shaped object is high in the middle of the manufacturing process, the temperature of the upper surface of the precursor 100, that is, the surface temperature of the solidified layer 24 which is a component thereof is constant. Can be.

Similarly, for example, it is determined that there is a temperature difference between the upper surface of the precursor 100 having a predetermined height during production and the upper surface of the precursor 100 at a height relatively lower than the predetermined height. If so, the temperature, flow rate, and / or flow velocity of the temperature control medium 61 flowing through the temperature control line in the base plate 20α is changed in the middle stage.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 80 or the like is driven to measure the temperature of the upper surface of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. Similarly, the temperature sensor 80 or the like is driven to measure the top surface temperature of the precursor 100 at a height relatively lower than the predetermined height. Based on the temperature measurement values of both, the arithmetic control unit 70 determines whether or not there is a difference between the temperature measurement values of both. When it is determined that there is a difference, the temperature control device 50 is driven under the instruction of the arithmetic control unit 70, and the temperature control medium supplied from the temperature control device 50 to the temperature control source 60 (temperature control line). The temperature, flow rate, and / or flow velocity are changed and controlled in the middle.

When it is determined that the temperature of the upper surface of the relatively high precursor 100 during production is higher than the temperature of the upper surface of the relatively low precursor 100 formed in the previous stage. The temperature is relatively lower than the initially constant temperature controlled medium temperature, preferably in addition to increasing the medium flow rate. In this case, at the time when the change control for lowering the medium temperature is started or in the vicinity thereof, the cooling action on the high region where the height of the model precursor 100 away from the base plate 20α is high is small. After that, when the change control for lowering the medium temperature is started and a predetermined time elapses, the high region where the height of the modeled precursor 100 away from the base plate 20α is high also begins to be cooled.

Finally, the thermal energy of the temperature control medium 61 can be transmitted to the upper surface region of the precursor 100 having a relatively high height, whereby the temperature of the upper surface region can be lowered. As a result, finally, the temperature of the upper surface of the precursor 100 having a relatively high height during production and the temperature of the upper surface of the precursor 100 having a relatively low height formed in the previous stage are obtained. The temperature difference between them can be reduced. As a result, in the middle of the manufacturing process, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, the surface temperature of the solidified layer 24 which is a component thereof can be made constant.

In the above, the case where the upper surface temperature of the precursor 100 in the middle of production at a predetermined height is higher than the upper surface temperature of the precursor 100 or the surface temperature of the base plate 20α at a height relatively lower than the predetermined height. Although described as an example, the case where the upper surface temperature of the precursor 100 at a predetermined height is lower than the upper surface temperature of the precursor 100 or the surface temperature of the base plate 20α at a relatively low height is not limited to this. Is also applicable.

In this case, for example, when it is determined that the temperature of the upper surface of the precursor 100 is lower than the surface temperature of the base plate 20α, the temperature is set relatively higher than the medium temperature whose temperature is controlled to be constant at the beginning, preferably this. In addition, reduce the medium flow rate. In this case, at the time when the change control for increasing the medium temperature is started or in the vicinity thereof, the low region where the height of the model precursor 100 adjacent to the base plate 20α is low can be first heated. At this point, the warming effect on the high region where the height of the model precursor 100 away from the base plate 20α is high is small. After that, when the change control for increasing the medium temperature is started and a predetermined time elapses, the high region where the height of the modeled precursor 100 away from the base plate 20α is high also begins to be heated.

Finally, the thermal energy of the temperature control medium 61 can be transmitted to the upper surface region of the precursor 100 having a relatively high height, whereby the temperature of the upper surface region can be raised. As a result, the temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α can be finally reduced. As a result, even when the height of the precursor 100 of the three-dimensional shaped object is high in the middle of the manufacturing process, the temperature of the upper surface of the precursor 100, that is, the surface temperature of the solidified layer 24 which is a component thereof is constant. Can be.

Similarly, it is determined that the temperature of the upper surface of the relatively high precursor 100 during production is lower than the temperature of the upper surface of the relatively low precursor 100 formed in the previous stage. In this case, the temperature is relatively higher than the initially constant temperature-controlled medium temperature, preferably in addition to reducing the medium flow rate. In this case, at the time when the change control for increasing the medium temperature is started or in the vicinity thereof, the heating action on the high region where the height of the model precursor 100 away from the base plate 20α is high is small. After that, when the change control for increasing the medium temperature is started and a predetermined time elapses, the high region where the height of the modeled precursor 100 away from the base plate 20α is high also begins to be heated.

Finally, the thermal energy of the temperature control medium 61 can be transmitted to the upper surface region of the precursor 100 having a relatively high height, whereby the temperature of the upper surface region can be raised. As a result, finally, the temperature of the upper surface of the precursor 100 having a relatively high height during production and the temperature of the upper surface of the precursor 100 having a relatively low height formed in the previous stage are obtained. The temperature difference between them can be reduced. As a result, in the middle of the manufacturing process, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, the surface temperature of the solidified layer 24 which is a component thereof can be made constant.

From the above, according to the above temperature control change, the temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α can be reduced. Further, the temperature difference between the temperature of the upper surface of the precursor 100 having a relatively high height during production and the temperature of the upper surface of the precursor 100 having a relatively low height formed in the previous stage is determined. It can be made smaller. Therefore, the occurrence of expansion or contraction of the solidified layer 24, which is a component of the precursor 100 corresponding to the temperature difference, can be suitably suppressed. As a result, the actual height of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

(Modeling process conditions: temperature of heat source element)
Not limited to the above embodiment, for example, when it is determined that there is a difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α when the precursor 100 in the process of production has a predetermined height. In addition, the temperature of the heat source element (heater element) as the temperature control source 60 may be changed.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 80 or the like is driven to measure the temperature of the upper surface of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. Similarly, the temperature sensor 80 or the like is driven to measure the top surface temperature of the precursor 100 at a height relatively lower than the predetermined height. Based on the temperature measurement values of both, the arithmetic control unit 70 determines whether or not there is a difference between the temperature measurement values of both. When it is determined that there is a difference, the temperature control device 50 is driven under the instruction of the arithmetic control unit 70 to change the temperature of the heat source element (heater element) as the temperature control source 60 from the temperature control device 50 on the way. Take control.

Also in this case, the temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α can be reduced. Further, the temperature difference between the temperature of the upper surface of the precursor 100 having a relatively high height during production and the temperature of the upper surface of the precursor 100 having a relatively low height formed in the previous stage is determined. It can be made smaller. Therefore, the occurrence of expansion or contraction of the solidified layer 24, which is a component of the precursor 100 corresponding to the temperature difference, can be suitably suppressed. As a result, the actual height of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

● Correspondence pattern under the premise that there is a temperature difference In the above, the case where the temperature, the flow rate, and / or the flow velocity of the temperature control medium 61 is selected as the modeling process condition is taken as an example. However, without being limited to this, the irradiation conditions of the light beam L and / or the thickness of the powder layer 22 may be selected as the modeling process conditions. Although these embodiments will be described in detail below, they are based on the idea that they correspond on the premise that there is a temperature difference (the temperature difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α). ..

For example, when it is determined that there is a difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α when the precursor 100 in the middle of production has a predetermined height, the powder layer 22 by the light beam irradiation unit 3 The irradiation conditions for the predetermined location may be changed.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 80 or the like is driven to measure the temperature of the upper surface of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. Similarly, the temperature sensor 80 or the like is driven to measure the surface temperature of the base plate 20α. Based on the temperature measurement values of both, the arithmetic control unit 70 determines whether or not there is a difference between the temperature measurement values of both. When it is determined that there is a difference, the light beam irradiation unit 3 is driven under the instruction of the arithmetic control unit 70, and the irradiation energy of the light beam L irradiated from the light beam irradiation unit 3 to a predetermined portion of the powder layer 22. , Spot diameter, and / or scanning speed may be changed.

For example, when the thickness of the new powder layer 22 to be formed immediately after shrinking along the height direction of the solidified layer 24 on the upper surface region side of the precursor 100 increases, the instruction of the arithmetic control unit 70 Below, the irradiation energy density of the light beam may be changed to increase during the manufacturing process so that the sintered state becomes as initially expected. Without being limited to this, in such a case, for example, under the instruction of the arithmetic control unit 70, the scanning speed of the light beam may be changed so as to be slower in the middle so that the sintered state becomes as initially expected. ..

On the other hand, when the thickness of the new powder layer 22 to be formed immediately after the solidification layer 24 on the upper surface region side of the precursor 100 is reduced due to the expansion along the height direction, the instruction of the arithmetic control unit 70 Below, the irradiation energy density of the light beam may be changed to be small during the manufacturing process so that the sintered state is as initially expected. Without being limited to this, in such a case, for example, under the instruction of the arithmetic control unit 70, the scanning speed of the light beam may be changed so as to be faster in the middle so that the sintered state is as initially expected. ..

As described above, even when the thickness of the new powder layer 22 formed immediately after the manufacturing process is increased or decreased in the middle of the manufacturing process, the powder is sintered by irradiating a predetermined portion of the new powder layer 22 with a light beam. Can be adjusted and changed as originally expected. As a result, the actual height of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

(Modeling process conditions: thickness of powder layer)
Further, for example, when it is determined that there is a difference between the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α when the precursor 100 in the process of manufacturing has a predetermined height, the base plate 20α (particularly the modeling table 20) ) May be changed as compared with the previous case, and the thickness of the next new powder layer 22 may be changed.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 80 or the like is driven to measure the temperature of the upper surface of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. Similarly, the temperature sensor 80 or the like is driven to measure the surface temperature of the base plate 20α. Based on the temperature measurement values of both, the arithmetic control unit 70 determines whether or not there is a difference between the temperature measurement values of both. If there is such a difference, it is determined that the solidified layer 24 on the upper surface region side of the precursor 100 of the modeled product can expand or contract along the height direction after a lapse of a predetermined time after the start of production. When such a determination is made, the lowering width of the base plate 20α (particularly the modeling table 20) is changed and controlled under the instruction of the arithmetic control unit 70. For example, when the thickness of the new powder layer 22 formed immediately after the expansion or contraction of the solidified layer 24 on the upper surface region side of the precursor 100 along the height direction is larger than the predetermined thickness. Under the instruction of the calculation control unit 70, the lowering width of the modeling table 20 may be reduced during manufacturing so that the thickness of the powder layer 22 becomes a predetermined thickness.

As described above, since the thickness of the new powder layer 22 formed immediately after the manufacturing process is changed and controlled, it is initially assumed that the powder is sintered by irradiating a predetermined portion of the new powder layer 22 with a light beam. You can adjust and change as you like. As a result, the actual height of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

When manufacturing a model precursor 100X having a "slender and tall" shape In the above "corresponding pattern for reducing the temperature difference", the area in the plan view is relatively small and the height is relative. In the case of producing a so-called "slender and tall" model, it is preferable to lower the medium temperature or increase the medium flow rate. Further, in the above-mentioned "correspondence pattern under the premise that there is a temperature difference", when a so-called "slender and tall" modeled object having a relatively small area in a plan view and a relatively high height is manufactured. Is preferably set to a low irradiation energy condition or the scanning speed is slowed down (see FIG. 1C).

The surface area (also referred to as heat dissipation area) that contributes to heat dissipation of the “slender and tall” model precursor 100X during manufacturing can be reduced as a whole. Therefore, it is difficult for the heat located in the model precursor 100X to be released from the surface of the model precursor 100X (specifically, the upper surface 101X) due to the surface heating of the model precursor 100X by the light beam L, and the temperature is controlled. It is difficult for the device 50 to remove heat.

As a result, heat tends to remain or be stored inside the modeled object precursor 100X, the temperature of the upper surface 101X of the modeled object precursor 100X becomes high, and the temperature of the upper surface 101X of the modeled object precursor 100X and the temperature-controlled modeling A temperature difference may occur with the temperature of the modeling plate 21 (that is, the base plate 20α) located on the table 20. When such a temperature difference occurs, the solidified layer 24X located on the upper surface 101X side of the precursor 100X of the modeled object can expand along the height direction. As a result, the height of the precursor 100X of the model being manufactured can be higher than the desired height. Therefore, the thickness of the next new powder layer can be reduced. In addition to this, since heat tends to remain or be stored inside the model precursor 100X, the temperature of the upper surface 101X (that is, the surface) of the model precursor becomes relatively high, and as a result, the powder layer 22 is predetermined. The powder 19 located at the location is easily melted and solidified.

For this reason, as described above, in the corresponding pattern for reducing the temperature difference, a so-called "slender and tall" model having a relatively small area in a plan view and a relatively high height is manufactured. In some cases, it is preferable to lower the medium temperature or increase the medium flow rate. Further, in the corresponding pattern under the premise that there is a temperature difference described above, in the case of manufacturing a so-called "slender and tall" model having a relatively small area in a plan view and a relatively high height, It is preferable to set low irradiation energy conditions or slow down the scanning speed (see FIG. 1C).

When manufacturing a model precursor 100Y that has a large area and a short height. On the other hand, in the above-mentioned "corresponding pattern for reducing the temperature difference", the area in the plan view is relatively large and the height is high. In the case of producing a relatively low, so-called "wide area and short" model, it is preferable to raise the medium temperature or reduce the medium flow rate. Further, in the above-mentioned "corresponding pattern under the premise that there is a temperature difference", in the case of manufacturing a so-called "wide area and short" modeled object having a relatively large area in a plan view and a relatively low height. It is preferable to set a high irradiation energy condition or increase the scanning speed (see FIG. 1D).

The surface area (also referred to as heat dissipation area) that contributes to heat dissipation of the modeled precursor 100Y that is "wide and short" during manufacturing can be large as a whole. Therefore, the heat located in the model precursor 100Y is likely to be released from the surface of the model precursor 100Y (specifically, the upper surface 101Y) due to the surface heating of the model precursor 100Y by the light beam L.

As a result, heat is less likely to remain inside the modeled object precursor 100Y, the temperature of the upper surface 101Y of the modeled object precursor 100Y becomes low, and the temperature of the upper surface 101Y of the modeled object precursor 100Y and the temperature-controlled modeling table 20 There may be a temperature difference with the temperature of the modeling plate 21 (ie, base plate 20α) located above. When such a temperature difference occurs, the solidified layer 24Y located on the upper surface 101Y side of the precursor 100Y of the modeled object can shrink along the height direction. As a result, the height of the precursor 100Y of the model being manufactured can be lower than the desired height. Therefore, the thickness of the next new powder layer can be increased. In addition to this, since heat is unlikely to remain inside the model precursor 100Y, the temperature of the upper surface 101Y (that is, the surface) of the model precursor becomes relatively low, and as a result, the powder layer 22 is located at a predetermined position. It becomes difficult to melt and solidify the located powder 19.

For this reason, as described above, in the corresponding pattern for reducing the temperature difference, a so-called "wide area and short" model having a relatively large area in a plan view and a relatively low height is manufactured. In this case, it is preferable to raise the medium temperature or reduce the medium flow rate. Further, in the corresponding pattern under the premise that there is a temperature difference described above, in the case of manufacturing a so-called "wide area and short" modeled object having a relatively large area in a plan view and a relatively low height. It is preferable to set a high irradiation energy condition or increase the scanning speed (see FIG. 1D).

In one embodiment of the present invention, it is preferable to adopt the following aspects.

(Predetermined time interval for changing the modeling process conditions)
In one aspect, it is preferable to change the modeling process conditions a plurality of times at predetermined time intervals and change the time interval based on the difference in height of the precursor 100 of the three-dimensional shaped model (FIG. 3). reference).

As described above, the technical idea of the present invention is to "change the modeling process conditions according to the height of the precursor of the three-dimensional shaped object during the manufacturing of the three-dimensional shaped object". In other words, the present invention has a technical idea that the modeling process conditions are changed in the middle of the production of the modeled object rather than being fixed.

In this regard, in this aspect, in addition to the technical idea, the modeling process conditions are changed a plurality of times at predetermined time intervals, and the difference in height of the precursor 100 of the three-dimensional shaped model is used. It is characterized in that the time interval of change is changed.

When the temperature control source 60 is positioned in the base plate 20α, the distance from the modeling table 21 is relatively short in the precursor 100A of the three-dimensionally shaped model having a relatively low height during manufacturing. Due to this, the difference between the top surface temperature of the precursor 100A and the temperature of the modeling table 21 is small. On the other hand, in the precursor 100B of the three-dimensional shaped model having a relatively high height during manufacturing, the upper surface temperature of the precursor 100B and the modeling table 21 are caused by the relatively short distance from the modeling table 21. There is a large difference from the temperature of.

In this regard, as newly discovered by the inventors of the present application, the solidified layer 24, which is a component of the precursor 100 of the three-dimensionally shaped model along the height direction, corresponds to the above temperature difference. Expansion or contraction can occur. From this fact, when the temperature difference is large, the solidified layer 24 located on the upper surface side of the precursor 100B of the three-dimensionally shaped model having a relatively high height corresponding to the above-mentioned temperature difference expands or expands along the height direction. The degree of contraction can be large. On the other hand, when the temperature difference is small, the expansion or contraction of the solidified layer 24 located on the upper surface side of the precursor 100A of the three-dimensional shaped object having a relatively low height corresponding to the temperature difference along the height direction. The degree can be small.

From the above, when the distance between the upper surface of the precursor 100 of the three-dimensional shape model during manufacturing and the modeling table 21 exceeds a predetermined reference value, the precursor of the three-dimensional shape model during production It is determined that the height of 100 is relatively high. When such a judgment is made, modeling is performed at a time interval relatively shorter than the time interval for carrying out the modeling process when the height of the precursor 100 of the three-dimensional shaped model in the process of manufacturing is relatively low. Change the process conditions. That is, in this embodiment, the time interval between the change and adjustment of the modeling process conditions at a predetermined timing and the change and adjustment of the next modeling process conditions is relatively shortened.

As a result, when the height of the precursor 100 of the three-dimensionally shaped object is relatively high as compared with the case where the height of the precursor 100 of the three-dimensionally shaped object being manufactured is relatively low, the above The frequency of changing the modeling process conditions to reduce the temperature difference can be increased. Therefore, it is possible to more preferably suppress the occurrence of expansion or contraction of the solidified layer 24 located in the upper surface region of the precursor 100 having a relatively high height along the height direction.

(Specific mode for measuring the temperature of the upper surface of the precursor of the three-dimensional shaped object)
Hereinafter, a specific mode for measuring the temperature of the upper surface of the precursor 100 of the three-dimensional shaped model will be described. Although not particularly limited, for example, the following aspects can be adopted.

In one aspect, the temperature of the upper surface of the precursor 100 of the three-dimensional shaped object may be measured based on the infrared rays provided from the upper surface (see FIG. 4).

In this embodiment, for example, an infrared radiation temperature sensor 81 may be used to receive infrared rays 82 from the upper surface 101 of the precursor 100, and indirectly measure the temperature on the upper surface 101 of the precursor 100 from the received infrared rays 82. Although not particularly limited, infrared rays may be received from the upper surface 101 of the precursor 100 to measure the overall temperature of the upper surface 101 (see the lower left figure of FIG. 4). Further, the upper surface 101 of the precursor 100 may be divided into a grid pattern in a monitor shape, and the temperature of a portion of the upper surface 101 located in a predetermined section may be measured (see the lower right figure of FIG. 4).

Specifically, under the instruction of the arithmetic control unit 70, the infrared radiation temperature sensor 81 is driven to generate infrared rays 82 from the upper surface 101 of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. It receives and converts the received information about the infrared ray 82 into the infrared radiation temperature sensor 81 itself or the arithmetic control unit 70. Thereby, the temperature on the upper surface 101 of the precursor 100 may be indirectly measured.

Further, for example, it is confirmed whether or not there is a temperature difference between the temperature of the surface of the base plate 20α measured separately and the temperature of the upper surface 101 of the precursor 100 measured through the infrared radiation temperature sensor 81. When the temperature difference exists, particularly when it can be determined that the temperature difference is relatively large, the occurrence of the temperature difference can be suitably suppressed by changing the above-mentioned modeling process conditions.

Since the infrared radiation temperature sensor 81 used in this embodiment is a non-contact type sensor, there is an advantage in that the temperature of the upper surface 101 of the precursor 100 can be measured without damaging the upper surface 101.

In one aspect, a step of cutting a three-dimensional shaped object using a cutting tool (end mill 40) is included, and a cutting tool having a temperature sensor 83 on the spindle is used, and the three-dimensional shaped object is used by the temperature sensor 83. The temperature of the upper surface 101 of the precursor 100 of the above may be measured (see FIG. 5).

In this embodiment, the temperature of the upper surface 101 of the precursor 100 is measured by using the temperature sensor 83 arranged on the spindle of the cutting tool used for surface cutting of the three-dimensional shaped object. The temperature measurement may be performed after being in direct contact with the upper surface 101 of the precursor 100. Without being limited to this, the temperature measurement may be performed in a non-contact state with respect to the upper surface 101 of the precursor 100.

Specifically, under the instruction of the arithmetic control unit 70, the temperature sensor 83 arranged on the spindle of the cutting tool is driven to drive the upper surface of the precursor 100 in the case where the precursor 100 in the process of manufacturing has a predetermined height. 101 is measured. Further, for example, it is confirmed whether or not there is a temperature difference between the temperature of the surface of the base plate 20α measured separately and the temperature of the upper surface 101 of the precursor 100 measured through the temperature sensor 83 arranged on the spindle of the cutting tool. When the temperature difference exists, particularly when it can be determined that the temperature difference is relatively large, the occurrence of the temperature difference can be suitably suppressed by changing the above-mentioned modeling process conditions.

In this embodiment, since the temperature sensor 83 is arranged on the main shaft of the cutting tool, the temperature sensor 83 can be indirectly moved with the operation of the cutting tool, so that the temperature sensor 83 can be moved independently. No separate mechanism is required to make it. Therefore, there is an advantage in that it is possible to preferably avoid the limitation of the modeling space in the chamber.

In one aspect, the powder layer 22 is formed using a squeezing blade 23, a squeezing blade 22 provided with a temperature sensor 84 is used, and the temperature sensor 84 is used as a precursor of a three-dimensional shaped object. The temperature of the top surface 101 of 100 may be measured (see FIG. 6).

In this embodiment, for example, the temperature sensor 84 arranged on the squeezing blade 23 is used to measure the temperature of the upper surface 101 of the precursor 100. The temperature measurement may be performed using a non-contact type temperature sensor 84A. Without being limited to this, the temperature measurement may be performed using the contact type temperature sensor 84B.

Specifically, the temperature sensor 84 arranged on the squeezing blade 23 is driven under the instruction of the arithmetic control unit 70, and the precursor 100 in the process of being manufactured has a predetermined height. The top surface 101 is measured. Further, for example, it is confirmed whether or not there is a temperature difference between the temperature of the surface of the base plate 20α measured separately and the temperature of the upper surface 101 of the precursor 100 measured through the temperature sensor 84 arranged on the squeezing blade 23. .. When the temperature difference exists, particularly when it can be determined that the temperature difference is relatively large, the occurrence of the temperature difference can be suitably suppressed by changing the above-mentioned modeling process conditions.

In this embodiment, since the temperature sensor 84 is arranged on the squeezing blade 23, the temperature sensor 84 can be indirectly moved according to the operation of the squeezing blade 23, so that the temperature sensor 84 is used. No separate mechanism is required to move it independently. Therefore, there is an advantage in that it is possible to preferably avoid the limitation of the modeling space in the chamber.

The above description has been made on the premise that the judgment criteria for changing the modeling process conditions are mainly based on the "temperature measurement value of the upper surface of the precursor 100 of the modeled product in the process of manufacturing". However, the present invention is not limited to this, and the “measured height value of the precursor 100 of the modeled object” may be used as a criterion for changing the modeling process conditions (see FIG. 7).

Specifically, in such a case, the height of the precursor 100 in the middle of production after a lapse of a predetermined time after the start of production is directly measured by using a height sensor 90 (also referred to as a height measuring unit) such as a laser displacement meter. To measure. Then, it is determined whether or not the actual height of the precursor 100 in the middle of production is different from the predetermined ideal height. If it can be determined that they are different, the modeling process conditions are changed in the middle.

As an example, a case where the temperature, flow rate, and / or flow velocity of the temperature control medium 61 flowing through the temperature control line as the temperature control source 60 is selected as the modeling process condition is taken as an example. In this case, if it can be determined that the actual height of the precursor 100 in the middle of production after a lapse of a predetermined time after the start of production is different from the predetermined ideal height, the temperature control medium 61 to be passed through the temperature control pipe in the base plate 20α Change the temperature, flow rate, and / or flow rate of.

Specifically, under the instruction of the arithmetic control unit 70, the height sensor 90 is driven to measure the actual height of the precursor 100 in the middle of production when a predetermined time has elapsed after the start of production. Next, the arithmetic control unit 70 compares the predetermined ideal height of the precursor 100 in the middle of production with the lapse of a predetermined time after the start of production with the actual measured height. Next, when it can be determined that the actual height is different from the ideal height, the temperature control device 50 is driven under the instruction of the arithmetic control unit 70 to move from the temperature control device 50 to the temperature control source 60 (temperature control line). The temperature, flow rate, and / or flow velocity of the provided temperature control medium is changed and controlled in the middle. For example, when it can be determined that the actual height of the precursor 100 is lower than the ideal height, the temperature control device 50 increases the temperature of the upper surface region of the precursor 100 under the instruction of the arithmetic control unit 70. A relatively high temperature temperature control medium may be flowed into the temperature control source 60 (temperature control line).

As a result, the thermal energy of the temperature control medium 61 can be suitably transferred to the upper surface region of the precursor 100 having a predetermined height after a lapse of a predetermined time after the start of production, and thereby the upper surface region of the precursor 100. The temperature of the can be changed. If the temperature of the upper surface region of the precursor 100 can be changed, the occurrence of a temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α can be suitably suppressed. As a result, in the middle of the manufacturing process, when the height of the precursor 100 of the three-dimensional shape model is different from the ideal height, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, its constituent elements. The surface temperature of the solidified layer 24 can be kept constant. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

In one embodiment of the present invention, the following aspects may be adopted.

In one aspect, the modeling process conditions may be changed according to the area of the upper surface 101 of the precursor 100 during the production of the precursor 100 of the three-dimensional shaped model (see FIG. 8).

In the stage of forming the solidified layer 24 using the light beam, when the area of the solidified layer 24 is relatively small, the irradiation heat of the light beam is more easily transmitted than when the area of the solidified layer 24 is relatively large. Due to this, the heat storage state of the solidified layer 24 is likely to continue. As a result, in the stacking direction of the solidified layer 24, it is relative to the surface temperature of the solidified layer having a relatively small area (that is, the temperature of the upper surface 101α of the precursor 100 having a relatively small area (area: S ₁ )). There may be a difference from the surface temperature of the solidified layer having a large area (that is, the temperature of the upper surface 101β of the precursor 100 having a relatively large area (area: S ₂ (> S ₁ ))). When the temperature difference occurs, the solidified layer 24 expands or contracts in the height direction correspondingly, and the height of the finally obtained three-dimensional shaped object is different from that desired. obtain.

Therefore, the change control of the modeling process conditions may be performed after paying attention to the area of the upper surface 101 of the precursor 100 during the manufacturing process.

For example, the upper surface 101 of the precursor 100 in the middle of production after a lapse of a predetermined time after the start of production is photographed using a camera 95 or the like. Then, the area of the upper surface 101 is calculated from the upper surface 101 of the photographed precursor 100 via the arithmetic control unit 70. When it can be determined that the area of the upper surface 101 of the precursor 100 exceeds the predetermined area threshold value after the lapse of a predetermined time, the modeling process conditions are changed on the way. Without being limited to this, when it can be determined that the area of the upper surface 101 of the precursor 100 after a lapse of a predetermined time is different from the predetermined ideal area as compared with the predetermined ideal area, the modeling process condition is set in the middle. You may change it.

Thereby, for example, the thermal energy of the temperature control medium 61 can be transmitted to the region of the solidified layer having a relatively large area (that is, the upper surface of the precursor 100 having a relatively large area), whereby the precursor 100 can be transmitted. The temperature of the upper surface area of the can be changed (increased or decreased). When it is possible to change the temperature of the upper surface region of the precursor 100, it is preferable to generate a temperature difference between the upper surface of the precursor 100 having a relatively large area and the upper surface of the precursor 100 having a relatively small area. It can be suppressed. As a result, in the middle of the manufacturing process, along the height direction of the precursor 100 of the three-dimensional shape model, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, the solidified layer 24 which is a component thereof. The surface temperature of the can be kept constant. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

Further, without being limited to the embodiment shown in FIG. 3, in one embodiment, the modeling process conditions are changed a plurality of times at predetermined time intervals, and three-dimensional shape modeling is performed when a predetermined time elapses after the start of production. The time interval may be changed based on the difference in the amount of heat of the precursor 100 of the substance (see FIG. 9).

In the middle of production, when the calorific value of the precursor 101 after a lapse of a predetermined time after the start of production is relatively large compared to the predetermined calorific value threshold value, the temperature of the precursor 100 having a relatively large calorific value due to this, particularly The top surface temperature can be high. On the other hand, when the calorific value of the precursor 101 does not exceed the predetermined calorific value threshold after the elapse of a predetermined time after the start of production, the calorific value of the precursor 101 is relatively larger than the predetermined calorific value threshold value of the precursor 100. The temperature, especially the top surface temperature, does not rise.

In view of such circumstances, in this embodiment, attention is paid to the calorific value of the precursor 100 after the elapse of a predetermined time, and the time interval for changing the modeling process conditions is changed based on the difference in the calorific value of the precursor 100 after the elapse of a predetermined time. ..

For example, when the temperature control source 60 is positioned in the base plate 20α, the calorific value of the precursor 101 after a lapse of a predetermined time after the start of production is measured with a calorimeter. Then, when it can be determined that the calorific value of the precursor 100 exceeds the predetermined calorific value threshold value after a lapse of a predetermined time, the modeling process is performed at a relatively short time interval as compared with the case where the calorific value does not exceed the predetermined calorific value threshold value. Change the conditions multiple times. That is, in this embodiment, when the calorific value of the precursor 100 exceeds the predetermined calorific value threshold value after a lapse of a predetermined time, the time from the change adjustment of the modeling process conditions to the next change adjustment of the modeling process conditions. Make the target interval relatively short on the way.

As a result, when it can be determined that the calorific value of the precursor 100 exceeds the predetermined calorific value threshold value after a lapse of a predetermined time, the frequency of changing the modeling process conditions can be increased due to the relatively short time interval. .. Thereby, for example, the thermal energy of the temperature control medium 61 is suitably transmitted to the upper surface region of the precursor 100 having a calorific value exceeding a predetermined calorific value threshold, specifically, the precursor 100 having a calorific value exceeding a predetermined calorific value threshold. be able to. Therefore, the temperature of the upper surface region of the precursor 100 having a calorific value exceeding a predetermined calorific value threshold value can be changed (increased or decreased). As a result, in the middle of the manufacturing process, along the height direction of the precursor 100 of the three-dimensional shape model, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, the solidified layer 24 which is a component thereof. The surface temperature of the can be kept constant. Therefore, it is possible to suitably suppress a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object.

In one aspect, the modeling process conditions may be changed based on the temperature of each upper surface 101 of the precursor 100 of the three-dimensional shaped model having different heights (see FIG. 10).

In the above, for example, whether to change the modeling process conditions after confirming whether there is a difference between the upper surface temperature of the precursor of the three-dimensional shaped model having a relatively high height during manufacturing and the temperature of the modeling table 21. Explained to judge. Without being limited to this, it is also preferable to confirm the presence or absence of a temperature change on each upper surface 101 of the precursors 100 having different heights during production. As a result, it can be determined that there is a temperature change not only in the height direction but also on the upper surfaces 101 of the precursors 100 having different heights during production, that is, on the surface of the solidified layer 24 (solidified portion 24a) which is a component thereof. In this case, the irradiation conditions may be changed in the later irradiation of the powder layer 22 to the predetermined portion by the light beam irradiation unit 3.

Specifically, under the instruction of the arithmetic control unit 70, a temperature sensor or the like is driven to measure the temperature of the upper surface 101 of the precursor 100 when the precursor 100 in the process of manufacturing has a predetermined height. If it can be determined that there is a temperature change on the surface of the solidified layer 24 at the temperature measurement stage, the light beam irradiation unit 3 irradiates a predetermined portion of the powder layer 22 at a later stage under the instruction of the arithmetic control unit 70. The conditions (irradiation energy, spot diameter, and / or scanning speed of the light beam L irradiated from the light beam irradiation unit 3 to a predetermined portion of the powder layer 22) may be changed.

As a result, the optimum "best" irradiation condition of the light beam L can be appropriately changed during the manufacturing of the modeled object. Therefore, the temperature of the upper surface 101 of the precursor 100 of the three-dimensional shape model, that is, the surface temperature of the solidified layer 24 which is a component thereof can be made constant. Therefore, it is possible to suitably suppress a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object. From the viewpoint of making the temperature of the upper surface 101 of the precursor 100, that is, the surface temperature of the solidifying layer 24 which is a component thereof, more constant, the optimum "best" irradiation of the light beam L for each formation of each solidifying layer 24 is performed. It is more preferable to change and adjust the conditions as appropriate.

In this embodiment, the actual height of the precursor 100 of the modeled product may be estimated based on the temperature of the upper surface 101 of the precursor 100 of the modeled product after a lapse of a predetermined time after the start of production.

The "actual height estimate" after a lapse of a predetermined time after the start of production can be calculated, for example, in the following manner. As an example, first, the temperature for each integral unit thickness is estimated from the temperature of the outermost surface of the modeled precursor at the lapse of a predetermined time after the start of production. Next, the degree of expansion in each integration unit is estimated from the temperature of each integration unit thickness. Then, the estimated value of the degree of expansion in each integration unit is integrated. As a result, the "actual height estimate" is calculated when a predetermined time has elapsed since the start of production. The calculation method is based on the idea that when the area of the integration unit changes when estimating the temperature and the degree of expansion, the area of the changing integration unit is also taken into consideration from the viewpoint of further improving the estimation accuracy. .. When the "actual height estimate" of the precursor 100 of the three-dimensional shape model is calculated from the temperature of the upper surface 101 of the precursor 100, the modeling process conditions can be appropriately changed according to the calculated value. It becomes. By changing the molding process conditions, the "actual height estimate" of the precursor 100 in the process of being manufactured can be brought close to a predetermined ideal height. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

[Manufacturing device for three-dimensional shaped object of the present invention]
Finally, a confirmatory description will be given of the three-dimensionally shaped object manufacturing apparatus according to the embodiment of the present invention.

As described above, the apparatus for manufacturing a three-dimensional shaped object according to an embodiment of the present invention includes a powder layer forming unit 2, a light beam irradiation unit 3, an arithmetic control unit 70, and at least one of a height measuring unit and a temperature measuring unit. To be equipped. Since the powder layer forming unit 2 and the light beam irradiation unit 3 have already been described in the [Powder bed fusion bonding method] column, description thereof will be omitted.

In one embodiment of the present invention, the arithmetic control unit 70 is a device capable of changing and controlling the above-mentioned modeling process conditions during the manufacturing of a three-dimensional shaped object. The height measuring unit (corresponding to the height sensor 90) is a measuring unit capable of measuring the height of the precursor 100 of the three-dimensional shaped object. The temperature measuring unit (corresponding to the temperature sensor 80, the infrared radiation temperature sensor 81, the temperature sensor 83, and the

temperature sensors

84, 84A, 84B) can measure the temperature of the upper surface 101 of the precursor 100 of the three-dimensional shaped object. It is a department. Further, the device may be connected to the temperature control device 50.

The above-mentioned components are electrically connected to the calculation control unit 70, and each component is individually configured to be able to control the operation according to the instruction of the calculation control unit 70.

Specifically, the arithmetic control unit 70 drives the temperature measuring unit to measure the temperature of the upper surface of the precursor 100 and the surface temperature of the base plate 20α when the precursor 100 in the process of manufacturing has a predetermined height. It is possible to instruct to do so. The arithmetic control unit 70 determines whether or not there is a difference between the two temperature measurement values based on the two temperature measurement values. When it is determined that there is a difference, the arithmetic control unit 70 is configured to drive the powder layer forming unit 2 so that the lowering width of the base plate 20α (particularly the modeling table 20) can be changed and controlled.

Further, the arithmetic control unit 70 drives the light beam irradiation unit 3 to determine the irradiation energy, spot diameter, and / or scanning speed of the light beam L irradiated from the light beam irradiation unit 3 to a predetermined portion of the powder layer 22. It is configured to be change controllable. The arithmetic control unit 70 drives the temperature control device 50 to change the temperature, flow rate, and / or flow velocity of the temperature control medium provided from the temperature control device 50 to the temperature control source 60 (temperature control line) on the way. It is controllable. Further, the arithmetic control unit 70 can drive the temperature control device 50 to change and control the temperature of the heat source element (heater element) as the temperature control source 60 from the temperature control device 50 on the way.

As a result, it is possible to change the temperature of the upper surface region of the precursor 100 having a predetermined height after a lapse of a predetermined time after the start of production, and the temperature difference between the upper surface of the precursor 100 and the surface of the base plate 20α is generated. It can be suitably suppressed. As a result, in the middle of the manufacturing process, when the height of the precursor 100 of the three-dimensional shape model is different from the ideal height, the temperature of the upper surface of the precursor 100 of the three-dimensional shape model, that is, its constituent elements. The surface temperature of the solidified layer 24 can be kept constant. As a result, a decrease in dimensional accuracy (particularly height accuracy) of the finally obtained three-dimensional shaped object can be suitably suppressed.

Although one embodiment of the present invention has been described above, it merely exemplifies a typical example of the scope of application of the present invention. Therefore, those skilled in the art will easily understand that the present invention is not limited to this, and various modifications can be made.

It should be noted that one embodiment of the present invention as described above includes the following preferred embodiments.
First aspect :
(I) A step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt and solidify the powder at the predetermined portion to form a solidified layer, and (ii) a new powder on the obtained solidified layer. A three-dimensional shaped product is manufactured by forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer by alternately and repeatedly laminating the powder layer and the solidified layer. How to do
A method for manufacturing a three-dimensional shaped object, in which the modeling process conditions are changed according to the height of the precursor of the three-dimensional shaped object during the production.
Second aspect :
In the first aspect, a method for manufacturing a three-dimensional shaped object, wherein the modeling process conditions are changed according to the height of the precursor based on the temperature of the upper surface of the precursor of the three-dimensional shaped object.
Third aspect :
In the first or second aspect, the modeling process is based on the difference between the temperature of the upper surface of the precursor of the three-dimensional shape model and the temperature of the base plate that is the base of the three-dimensional shape model to be manufactured. A method of manufacturing a three-dimensional shaped object that changes the conditions.
Fourth aspect :
In any of the first aspect to the third aspect, the three-dimensional shape modeling is performed by changing the modeling process conditions based on the temperature of each upper surface of the precursor of the three-dimensional shape modeling object having different heights. How to make things.
Fifth aspect :
In any of the first to fourth aspects, the modeling process conditions are changed a plurality of times at predetermined time intervals.
A method for producing a three-dimensionally shaped object, wherein the time interval is changed based on the difference in height of the precursor of the three-dimensionally shaped object.
Sixth aspect :
In the fifth aspect, when the height of the precursor of the three-dimensional shape model is relatively high, the three-dimensional shape modeling is performed by changing the modeling process conditions at the relatively short time interval. How to make things.
Seventh aspect :
In any of the first to sixth aspects, the modeling process conditions include the temperature, flow rate and flow velocity of the temperature control medium contained in the base plate, the temperature of the heat source element contained in the base plate, and the powder layer. A method for manufacturing a three-dimensional shaped object, in which at least one is selected from the group consisting of the thickness and the irradiation conditions of the light beam.
Eighth aspect :
In any one of the second aspect to the seventh aspect, the temperature of the upper surface of the precursor of the three-dimensional shape model is measured based on the infrared rays provided from the upper surface. Production method.
Ninth aspect :
In any one of the second aspect to the eighth aspect, the step of cutting the three-dimensional shaped object by using a cutting tool is included.
A method for manufacturing a three-dimensional shaped object, wherein a cutting tool having a temperature sensor on a spindle is used, and the temperature of the upper surface of the precursor of the three-dimensional shaped object is measured by the temperature sensor.
Tenth aspect :
In any of the second to ninth aspects, the formation of the powder layer is carried out using a squeezing blade.
A method for manufacturing a three-dimensional shaped object, wherein a squeezing blade provided with a temperature sensor is used, and the temperature of the upper surface of the precursor of the three-dimensional shaped object is measured by the temperature sensor.
Eleventh aspect :
In the first aspect, the height of the precursor of the three-dimensionally shaped object is actually measured, and there is a difference between the measured value of the height and the theoretical value of the predetermined height of the precursor calculated in advance. A method for manufacturing a three-dimensional shaped object, in which the modeling process conditions are changed in some cases.
12th aspect :
It is a device for manufacturing three-dimensional shaped objects.
Powder layer forming part,
Light beam irradiation unit for forming a solidified layer from a powder layer,
An arithmetic control unit that can change and control the modeling process conditions during the manufacturing of the three-dimensional shaped object, and
An apparatus including at least one of a height measuring unit capable of measuring the height of a precursor of the three-dimensional shape model and a temperature measuring unit capable of measuring the temperature of the upper surface of the precursor of the three-dimensional shape model.

Various articles can be manufactured by implementing the method for manufacturing a three-dimensional shaped object according to an embodiment of the present invention. For example, in "when the powder layer is an inorganic metal powder layer and the solidified layer is a sintered layer", the obtained three-dimensional shaped product is a plastic injection molding die, a press die, a die casting die, and the like. It can be used as a die for casting dies, forging dies, and the like. On the other hand, in the case of "when the powder layer is an organic resin powder layer and the solidified layer is a cured layer", the obtained three-dimensional shaped molded product can be used as a resin molded product.

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2019-085882 (Filing date: April 26, 2019, title of invention: "Method for manufacturing a three-dimensional shaped object and an apparatus for manufacturing a three-dimensional shaped object". ) Under the Paris Convention. All content disclosed in this application is incorporated herein by reference.

2 Powder layer forming part 3 Light beam irradiation part 19 Powder 20 Modeling table 20α Base plate 21 Modeling plate 22 Powder layer 23 Squeezing blade 24 Solidification layer 40 Cutting tool 60 Temperature control source 61 Temperature control medium 70

Calculation control unit

80, 81, 83, 84, 84A, 84B Temperature measuring unit (temperature sensor)
90 Height measuring unit (height sensor)
100, 100A, 100B, 100X, 100Y Precursor of

3D shape model

101, 101X, 101Y Top surface of precursor of 3D shape model L light beam

Claims

(I) A step of irradiating a predetermined portion of the powder layer with a light beam to sinter or melt and solidify the powder at the predetermined portion to form a solidified layer, and (ii) a new powder on the obtained solidified layer. A three-dimensional shaped product is manufactured by forming a layer and irradiating a predetermined portion of the new powder layer with a light beam to form a further solidified layer by alternately and repeatedly laminating the powder layer and the solidified layer. How to do
A method for manufacturing a three-dimensional shaped object, in which the modeling process conditions are changed according to the height of the precursor of the three-dimensional shaped object during the production.
The method for manufacturing a three-dimensional shaped object according to claim 1, wherein the modeling process conditions are changed according to the height of the precursor based on the temperature of the upper surface of the precursor of the three-dimensional shaped object.
The modeling process conditions are changed based on the difference between the temperature of the upper surface of the precursor of the three-dimensionally shaped object and the temperature of the base plate that is the base of the three-dimensionally shaped object to be manufactured. 2. The method for manufacturing a three-dimensional shaped object according to 2.
The production of the three-dimensional shape model according to any one of claims 1 to 3, wherein the modeling process conditions are changed based on the temperature of each upper surface of the precursor of the three-dimensional shape model having different heights from each other. Method.
The modeling process conditions are changed a plurality of times at predetermined time intervals.
The method for producing a three-dimensional shaped object according to any one of claims 1 to 4, wherein the time interval is changed based on the difference in the height of the precursor of the three-dimensional shaped object.
The three-dimensional shape modeling according to claim 5, wherein when the height of the precursor of the three-dimensional shape model is relatively high, the modeling process conditions are changed at the relatively short time interval. How to make things.
The modeling process conditions include the temperature, flow rate and flow velocity of the temperature control medium contained in the base plate, the temperature of the heat source element contained in the base plate, the thickness of the powder layer, and the irradiation conditions of the light beam. The method for producing a three-dimensional shaped object according to any one of claims 1 to 6, wherein at least one is selected from the group.
The method for manufacturing a three-dimensional shaped object according to any one of claims 2 to 7, wherein the temperature of the upper surface of the precursor of the three-dimensional shaped object is measured based on infrared rays provided from the upper surface.
Including the step of cutting the three-dimensional shaped object using a cutting tool.
The method according to any one of claims 2 to 8, wherein a cutting tool having a temperature sensor on the spindle is used, and the temperature of the upper surface of the precursor of the three-dimensional shaped object is measured by the temperature sensor. A method for manufacturing a three-dimensional shaped object.
The formation of the powder layer was carried out using a squeezing blade.
The invention according to any one of claims 2 to 9, wherein a squeezing blade provided with a temperature sensor is used, and the temperature of the upper surface of the precursor of the three-dimensional shaped object is measured by the temperature sensor. A method for manufacturing a three-dimensional shaped object.
The height of the precursor of the three-dimensional shape model is actually measured, and when there is a difference between the measured value of the height and the theoretical value of the predetermined height of the precursor calculated in advance, the modeling is performed. The method for manufacturing a three-dimensional shaped object according to claim 1, wherein the process conditions are changed.
It is a device for manufacturing three-dimensional shaped objects.
Powder layer forming part,
Light beam irradiation unit for forming a solidified layer from a powder layer,
An arithmetic control unit that can change and control the modeling process conditions during the manufacturing of the three-dimensional shaped object, and
An apparatus including at least one of a height measuring unit capable of measuring the height of a precursor of the three-dimensional shape model and a temperature measuring unit capable of measuring the temperature of the upper surface of the precursor of the three-dimensional shape model.