WO2016031387A1 - Method for manufacturing shaped article, control device, and shaped article - Google Patents

Abstract

This control device (1) comprises a layer data creation unit (14) which slices three-dimensional shape data of a shaped article into a plurality of layers, creates layer data containing, as a first sintering region, a part where the shaped article exists in each of the sliced layers, modifies the first sintering region to an unsintered region in a plurality of layers which correspond to a division position in the created layer data, and adds a second sintering area for sintering an unsintered part existing across the plurality of layers corresponding to the division position; and an operation instruction creation unit (17) which creates an operation instruction to form a connection part in the shaped article by sintering the second sintering region after sintering the first sintering region of each coating layer of a molding material.

Description

Modeled object manufacturing method, control device, and modeled object Import by reference

This application claims the priority of Japanese Patent Application No. 2014-174707 filed on August 29, 2014, and is incorporated herein by reference.

The present invention relates to a molded article manufacturing method, a control device, and a molded article.

There is known a method of manufacturing a shaped object obtained by irradiating a metal powder with laser light to sinter the metal powder. In this manufacturing process, a sintered layer is formed by sintering a layer of metal powder, and a new layer of metal powder is coated on the sintered layer and integrated with the lower sintered layer. It is a process of repeatedly forming a body.

Patent Document 1 describes a process of dividing an irradiation plane into a plurality of modeling areas, sequentially moving a scanning head to a modeling area that is not adjacent to each other, and irradiating a light beam. ing. Thereby, the heat accumulation of sintering heat does not generate | occur | produce in a molded article, the thermal distortion of a molded article is prevented, and the processing precision of a molded article improves.
Patent Document 2 describes a process of heating a formed sintered layer to remove residual stress. Thereby, an optical modeling thing with small curvature can be manufactured.

JP 2009-108350 A JP 2007-270227 A

Depending on the cooling period after sintering, there may be a portion of the sintered layer where a tensile force accompanying thermal contraction occurs. This tensile force affects other parts of the modeled object, and may greatly change the shape and dimensions of the entire modeled object, contrary to the intention of the design data.
Although the method for manufacturing a shaped article disclosed in Patent Documents 1 and 2 provides local allowance for the heat of sintering, it does not yet prevent an unintended change of the entire shaped article due to a tensile force.

Therefore, the main object of the present invention is to reduce the degree of deformation of the shaped object due to thermal shrinkage after sintering and to produce a highly accurate shaped object.

In order to solve the above-mentioned problem,
In order to produce a green body that forms a plurality of layers by repeating formation of a layer coated with a molding material and sintering of the layer, the coating and A lamination process that repeats sintering;
And a connecting step of forming a connecting portion on the shaped article by sintering an unsintered portion extending over the plurality of layers.
Other means will be described later.

According to the present invention, it is possible to reduce the degree of deformation of a shaped object due to thermal shrinkage after sintering, and to manufacture a highly accurate shaped object.

It is a block diagram which shows the molded article manufacturing system regarding one Embodiment of this invention. FIG. 2A is a configuration diagram illustrating a modeling apparatus including one sintering mechanism. FIG. 2B is a configuration diagram illustrating a modeling apparatus including two sintering mechanisms. Fig.3 (a) is a three-dimensional view which shows a molded article. FIG.3 (b) is a three-dimensional view which shows each element of a molded article. FIG.3 (c) is a three-dimensional view which shows the flat plate of a molded article. FIG. 4A is a configuration diagram showing shape element data. FIG. 4B is a configuration diagram showing element division data. FIG. 4C is a three-dimensional view showing a three-dimensional display of the element division data. It is a block diagram which shows each element of the molded article based on the shape element data regarding one Embodiment of this invention. FIG. 6A is a cross-sectional view showing data for lamination before division. FIG. 6B is a front view showing a component obtained by stacking the stacking data of FIG. FIG. 7A is a configuration diagram illustrating a division result of the stacking data illustrated in FIG. FIG. 7B is a front view showing a component obtained by stacking the stacking data of FIG. FIG. 8A is a configuration diagram showing the data for stacking in FIG. FIG. 8B is a configuration diagram showing the connection data in FIG. Fig.9 (a) is explanatory drawing which shows the formation process of the molded article of Fig.7 (a). FIG.9 (b) is a front view which shows the molded article of Fig.9 (a). It is a block diagram which shows the operation command for performing the formation process of the molded article of Fig.9 (a) regarding one Embodiment of this invention. Fig.11 (a) is a flowchart which shows the main process of modeling thing manufacture. FIG. 11B is a flowchart showing details of the element division processing. It is a flowchart which shows the detail of the instruction creation process regarding one Embodiment of this invention. It is a top view which shows the sintering start time (FIG. 13 (a)) in the lamination | stacking process of the beam in a comparative example, and the sintering end time (FIG.13 (b)). 14 (a) and 14 (b) are front views showing an example of a model different from FIG. 9 (b).

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram illustrating a model manufacturing system.
The model production system includes the terminal 9, the control device 1, and the modeling device 100. The terminal 9 and the control device 1 are connected by a connection line 92, and the control device 1 and the modeling apparatus 100 are connected by a connection line 91.
Each apparatus (the terminal 9, the control apparatus 1, and the modeling apparatus 100) of the molded article manufacturing system includes at least a memory serving as a storage unit used when performing arithmetic processing and an arithmetic processing apparatus that performs the arithmetic processing. It is assumed that a computer is provided or built in. The memory of this computer is constituted by a RAM (Random Access Memory) or the like. Arithmetic processing is realized by an arithmetic processing unit configured by a CPU (Central Processing Unit) executing a program on a memory.

The terminal 9 transmits 3D shape data of the modeled object to be created by the user as the shape element data 11 to the control device 1 via the connection line 92.
The control device 1 creates a modeling process (operation command 18) of a modeled object that does not cause shape distortion due to residual stress due to thermal contraction, and transmits the operation command 18 to the modeling device 100 via the connection line 91.
The modeling apparatus 100 is driven according to the received operation command 18 and irradiates a molding material such as a metal powder with a laser or an electron beam to sinter it, thereby creating a modeled object. Note that, as will be described later with reference to FIG. 5 and the like, one modeled object is composed of one or more elements for configuring the modeled object.

The control device 1 includes a CPU (Central Processing Unit) that is a control mechanism for executing each processing unit (the control unit 10, the element division unit 12, the layer data creation unit 14, and the operation command creation unit 17), This is a computer having storage means for storing each data (shape element data 11, element division data 13, stacking data 15, connection data 16, and operation command 18). Each component in these control apparatuses 1 is connected by the connection line 93 which is an in-device bus.

The control unit 10 is a central processing unit that activates other processing units (the element division unit 12, the layer data creation unit 14, and the operation command creation unit 17) and controls the operation of the entire control device 1.
The element dividing unit 12 specifies, from the shape element data 11, an element that causes a residual stress or a shape distortion due to thermal contraction among components of a modeled object to be created. Then, the element division unit 12 creates a division token indicating the division position for the identified element, and writes the division token as element division data 13. That is, by dividing an element at a division position that is a part of a modeled object, it is possible to reduce the influence of residual stress and shape distortion.

The layer data creation unit 14 creates stacking data 15 obtained by dividing the shape element data 11 according to the element division data 13 and connection data 16 for connecting the division positions. The data for lamination 15 and the data for connection 16 are information necessary for a powder sintering additive manufacturing process by laser irradiation.
The operation instruction creating unit 17 creates an operation instruction 18 composed of a series of instructions based on the stacking data 15 and the connection data 16, and sequentially sends the created instructions to the modeling apparatus 100 via the connection line 91. Send.
The operation command 18 records the stack thickness of the shaped object to be powder-sintered and a series of command sequences described later in FIG. 10, and the stack thickness is usually any one of 0.1 mm to 0.5 mm. In the following, an example of “lamination thickness = 0.5 mm” will be described.

FIG. 2A is a configuration diagram illustrating a modeling apparatus 100 including one sintering mechanism (laser apparatus for two-dimensional laser scanning).
The modeling apparatus 100 manufactures the modeled object 119 according to the operation command 18 from the control apparatus 1. Therefore, the modeling apparatus 100 includes a carbon dioxide laser oscillator 110, a collimator 111, a reference table 112, a galvano scanning device 113, a condensing lens 114, a squeegee 116, a base 120, a lifting table 121, and a lifting table 122. And an elevating mechanism 123 and an elevating mechanism 124.

The carbon dioxide laser oscillator 110 generates pulsed laser light 115. The collimator 111 adjusts the beam diameter of the laser beam 115. The galvano scanning device 113 guides the laser beam 115 to a predetermined location. The condensing lens 114 condenses the laser beam 115 and locally sinters the metal powder. The modeled object 119 is obtained by sintering and laminating a part of the metal powder 118 being modeled. That is, each component of the shaped object 119 is obtained by laminating layers of sintered metal powder 118.
Therefore, the pulsed laser beam 115 emitted from the carbon dioxide laser oscillator 110 is adjusted in beam diameter by the collimator 111, guided to a predetermined place by the galvano scanning device 113, condensed by the condenser lens 114, and the modeled object 119. The metal powder 118 placed above is irradiated.

As for the irradiation mechanism of the laser beam 115 described above (such as the carbon dioxide laser oscillator 110), a 400 watt laser device may be used as a heat source, or an electron beam device may be used instead of the carbon dioxide laser oscillator 110. For example, laser irradiation was performed with a beam spot diameter of 0.5 mm, a pulse width of 3.0 ms, an operation speed of 9 mm / s, and an oscillation frequency of 90 Hz. Further, nickel particles having a particle diameter of 65 μm to 90 μm are used for the metal powder 117, but other particles may be used.
Further, instead of the laser beam 115, other sintering means such as an electron beam may be used.

The reference table 112 defines a reference position for the height of the metal powder 117 and the metal powder 118. The squeegee 116 supplies the metal powder 117 to the metal powder 118 being shaped. The base 120 supports the metal powder 118.
The lifting table 121 sets the metal powder 117 to a predetermined height as needed. The raising / lowering table 122 descends from the height of the reference table 112 at any time by the thickness to be laminated. The elevating mechanism 123 drives the elevating table 121 up and down. The elevating mechanism 124 drives the elevating table 122 up and down.
Assuming that the lift table 121 and the lift table 122 have the same area, the amount of the metal powder 117 supplied from the lift table 121 to the lift table 122 and the lift table 122 are the same as long as the lift and drop distances of the respective tables are equal. The amount of metal powder 118 that can be received from the lifting table 121 is equal.

FIG. 2B is a configuration diagram illustrating the modeling apparatus 100 including two sintering mechanisms. The difference from FIG. 2A is that the second laser beam 115b sintering mechanism (a carbon dioxide laser oscillator 110b, a collimator 111b, a galvano scanning device 113b, and a condenser lens 114b) is added to the modeling device 100 of FIG. This is an added point.
The laser beam 115 in FIG. 2B is irradiated for stacking according to a command LaserBeam described later.
The laser beam 115b in FIG. 2B is irradiated for connection according to a command JointLaserBeam described later. In addition, since the order JointLaserBeam connects the objects that are sintered and laminated in a plurality of layers, the thickness of sintering performed at one time is different.

The connecting sintering mechanism and the laminating sintering mechanism may be configured to be different from each other, as exemplified below.
The laser irradiation mechanism itself is provided as a physically separate object (FIG. 2B).
-The laser irradiation output for connection is made stronger than the laser irradiation output for lamination.
-The laser irradiation time for connection is made longer than the laser irradiation time for stacking.
The laser irradiation range for connection is made narrower (locally) than the laser irradiation range for stacking.
An electron beam having a low reflectivity to the metal powder 118 is used for connection irradiation, and a laser having a high reflectivity to the metal powder 118 is used for stacking irradiation.

FIG. 3A is a three-dimensional view showing a modeled object. The terminal 9 activates SOLIDWORK (registered trademark) of 3D-CAD (Computer Aided Design) software, for example, and causes the user to create 3D shape data of the modeled object 119. Then, the control device 1 receives the created 3D shape data from the terminal 9 and records it as shape element data 11 in its storage means.

FIG. 3 (b) is a three-dimensional view showing each element of the shaped article of FIG. 3 (a). The shape element data 11 is composed of elements E (E1, E2, E3, E4, E5). In the section from the left broken line where the element E1 within the element E is arranged to the right broken line where the element E2 is arranged (section where the element E3 is arranged), the free movement of the element E3 due to thermal contraction is restricted. The distortion of the shape due to the thermal stress occurs in the element E3 and the elements E1 and E2 in the section.

FIG.3 (c) is a three-dimensional view which shows the flat plate of the element E5 among the molded objects of FIG.3 (b). The element dividing unit 12 logically separates one element E5 into three elements (E51, E52, E53) (instead of physically cutting the modeled object, it is separated in the computer of the control device 1 only) As data).
Element E51 is a section from the left dashed line to the right dashed line of element E5.
Element E52 is a section from the left end of element E5 to the left broken line.
Element E53 is a section from the right dashed line to the right end of element E5.
Thus, by separating the element E5 as the element E51 that is affected by the thermal stress and the elements E52 and E53 that are not affected by the thermal stress, the elements to be divided can be reduced (limited).

FIG. 4A is a configuration diagram showing a data format in which the shape element data 11 of FIG. 3A is stored.
The shape element data 11 includes, for each element, an element ID for specifying the element, a type as the shape of the element, a reference point position (x, y, z) where the element is arranged, and the element Correlate with the dimensions.
The notation (x, y, z) is an xyz coordinate system (spatial coordinate system) in which the bottom surface is set to z = 0. The numerical values of dimensions are in units of mm and are in the form of (vertical, horizontal, height) or (diameter, height).
Further, although not shown, connection information between elements (information indicating whether or not to be restrained) such as “the element E3 is sandwiched between the elements E1 and E2” is also the shape element data. 11 is included.

FIG. 4B is a configuration diagram showing the element division data 13. The element division unit 12 determines an element that needs to be divided and a division position in the element from each element of the shape element data 11, and writes the result to the element division data 13.
The element division data 13 includes, for each element, a division flag indicating whether the element needs to be divided (= 1) or not (= 0), and a division position (x, y, z) in the element when dividing. And correspond. This division position (x, y, z) is indicated by a relative value from the reference point position of the element.
FIG. 4C is a three-dimensional view showing a three-dimensional display of the element division data 13 of FIG. A division token indicating the division position (0, 40, 0) is set for the element E3 with the division flag = 1.

FIG. 5 is a configuration diagram showing each element of a modeled object based on the shape element data 11 of FIG.
Each element has a "classification" that indicates the connection relationship with other elements as seen from itself, its own element "dimension = representative dimension (mm) (vertical x horizontal x height)", and its own element "aspect" The ratio (vertical, horizontal, height) "is associated with the" division position (relative position) "of its own element.
If the element dimensions (vertical x horizontal x height) = (L x W x H) and the typical dimensions of this element are Rp = L + W + H, then the aspect ratio (vertical, horizontal, height) = (L / Rp, W / Rp, H / Rp). In addition, the dimension of the cylinder regards the diameter as the vertical length and the horizontal length.

The “classification” in FIG. 5 is one of the following three types.
The “link part” in the classification is an element having a region where a tensile force is generated by heat shrinkage. That is, the link portion is an element (element E) connected to other elements (for example, elements E1 and E2) at a plurality of locations so that the shape of the element itself cannot be changed due to heat shrinkage.
The “connection part” in the classification is an element connected to the link part. That is, the connection part is an element connected to the link part so that the force is transmitted with the thermal contraction of the link part to be connected, but the shape of the link part cannot be changed by the force.
The “element part” in the classification is an element that does not correspond to the link part or the connection part. Since the element portion is connected to other elements at 0 to 1 places, it can move freely, so that no stress or distortion occurs.

The classification and dimensions of the shape element data 11 are input in advance from the terminal 9 or the like.
The element dividing unit 12 calculates the aspect ratio from the dimensions of the shape element data 11 as described above.
The element dividing unit 12 installs a dividing token in a link part in which the aspect ratio excluding the stacking direction (Z-axis height direction) exceeds the threshold value 0.8 (such as the element E3 in FIG. 4C). Although the threshold value is 0.8 here, the user sets an appropriate numerical value depending on the metal material to be used and the strength required for the modeled object 119.
The reason why the stacking direction is excluded from the threshold determination process is that the stacking direction is a free end, free contraction due to thermal contraction is possible, stress is not accumulated, and the shape is not distorted.

FIG. 6A is a cross-sectional view showing the lamination data 15 before division. FIG. 6B is a front view showing a component obtained by stacking the stacking data 15 of FIG.
The layer data creation unit 14 scans (slices) the 3D shape indicated by the shape element data 11 in FIG. 3A on the XY plane for each layer from the bottom surface (z = 0) to the top surface, and the 3D shape exists. The portion 15 to be processed is defined as the hatched region (location where powder sintering is performed), and the portion where the three-dimensional shape does not exist is defined as the white region (location where powder sintering is not performed), thereby creating the data 15 for lamination in FIG.

The created stacking data 15 is a cross-sectional view from the bottom surface (z = 0) to the top surface of the modeled object. In the following, a layered object having a layer thickness of 0.5 mm is laminated by one powder sintering lamination process, and one layer indicates a layered object of twice (1 mm). FIG. 6A illustrates 12 layers L1 to L12. The sectional view of each layer is stored as a separate file for each layer ID.

FIG. 7A is a configuration diagram showing a division result of the stacking data 15 of FIG. FIG. 7B is a front view showing a component obtained by stacking the stacking data 15 of FIG.
The layer data creation unit 14 reflects the element division data 13 by performing the following two procedures on the stacking data 15 shown in FIG.

(Procedure 1) is a process of dividing the stacking data 15. The layer data creation unit 14 identifies the element E3 to be divided (the division flag of the element division data 13 is 1) in the lamination data 15, and sets the division position in the element E3 to the element division data 13 from. Then, the layer data creation unit 14 divides the element E3 by converting a hatched area around the identified division position (for example, an ellipsoid 404 centered on the division position) into a white area.
In FIG. 7A, as a result of the element division, the hatched area for five layers L8 to L12 is converted into a white area. As described above, the element division may extend over a plurality of layers or only one layer.
That is, the layer data creation unit 14 converts the hatched region into a white region so that an unsintered portion extending over a plurality of layers is generated by (Procedure 1).

(Procedure 2) is a connection process of the stacking data 15 divided in (Procedure 1). The layer data creation unit 14 creates a new layer J 12 (5) as the connection data 16. Note that “J” in the layer J12 (5) indicates a connection (Joint), “12” indicates the uppermost layer (L12 in this example), and “5” indicates the connection depth ( Here, five layers L8 to L12) are shown.
The layer data creation unit 14 includes a hatched area 403 that is an area for performing laser irradiation for connection to the division position of (Procedure 1) on the new layer J12 (5), and a connection area. And a mark 402 for clearly indicating to the user. Then, the layer data creation unit 14 associates the layer J12 (5) and the connection target L12 with the link 401.
That is, the layer data creation unit 14 creates the connection data 16 so as to sinter the unsintered portion extending over the plurality of layers generated in (Procedure 1) by (Procedure 2).

Note that the white region (region converted for division) in (Procedure 1) and the hatched region 403 (region converted for connection) in (Procedure 2) may be the same size or position, or white The hatched area 403 may be larger than the area (for example, the hatched area 403 having the same centroid and an area increased by 30% as compared with the white area). The larger region is defined by the shrinkage of the laminate in the horizontal direction (direction perpendicular to the lamination direction) due to the thermal contraction of the laminate during the cooling period after the divided layered object is formed. This is to cope with an event in which the gap between the two becomes large.

FIG. 8A is a configuration diagram showing the stacking data 15 of FIG. The stacking data 15 associates the layer ID with the division flag for each layer number. In the stacking data 15 in FIG. 7A, five layers L8 to L12 are divided, but in the stacking data 15 in FIG. 8A, only L12 has a split flag = 1. This is because the division flag indicates whether or not the link 401 created by the layer data creation unit 14 in (Procedure 2) exists. That is, the connection data 16 is associated with the layer with the division flag = 1.
FIG. 8B is a configuration diagram showing the connection data 16 of FIG. The connection data 16 is associated with a connection data ID (ID of the connection data 16) for each layer number.

Fig.9 (a) is explanatory drawing which shows the formation process of the molded article of Fig.7 (a).
At reference numeral 311, the columns 301 and 302 are fixed on the base, and the lasers 303 and 304 are irradiated so as to connect the columns.
Next, at reference numeral 312, the beams 303 b and 304 b are formed by the lasers 303 and 304, and the space 309 between the beams is divided as indicated by the stacking data 15 in FIG.

At 313, the molten and solidified metal material is cooled and contracted. At this time, there is a gap between the beams 303c and 304c because the stacking data 15 of (Procedure 1) is divided. Therefore, the beams 303c and 304c are each provided with an end face that can freely move, so that a reduction in the volume of the beam due to thermal contraction does not affect the columns 301 and 302, no tensile force is generated, and no stress remains.
At reference numeral 314, after filling the space 309 with metal powder and filling the gap generated between the beams, the beams 303 c and 304 c are connected by the connection unit 305 by laser irradiation based on the connection data 16 in (Procedure 2). By connecting, the two beams 303c and 304c are integrated as one beam, and the strength required for modeling is ensured.

FIG.9 (b) is a front view which shows the molded article of Fig.9 (a).
Since the pillars 301 and 302 and the beams 303c and 304c of the modeled object are formed by lamination processing, each layer indicated by a horizontal line is illustrated in FIG. 9B. On the other hand, the connection portion 305 is formed at a time without being stacked by a connection process extending over a plurality of layers, so that it is distinguished from a layer indicated by a dotted pattern in FIG. 9B and indicated by a horizontal line.
9B and the modeled object of FIG. 13, the range in which the stress due to the thermal shrinkage of the beam is determined from the distance of the entire beam (beam 303c + connecting part 305 + beam 304c). The distance is reduced to 305. Therefore, the tensile force accompanying heat shrinkage can be reduced, and residual stress and shape distortion can be reduced.

FIG. 10 is a configuration diagram showing an operation command 18 for performing the formation process of the shaped article of FIG.
First, it is assumed that the metal powder 118 and the modeled object 119 do not exist in the initial state before the operation instruction 18 is executed, and the metal powder 117 to be used for manufacturing from now on is sufficiently provided.
The operation command creating unit 17 creates an operation command 18 from the stacking data 15 and the connection data 16 as shown below.

The command Initial on the first line is a command for aligning the base 120 to the height of the reference table 112 in order to set the modeling apparatus 100 in the initial state.
The commands on the 2nd to 5th lines are the first sintering process in the laminating process of the first layer (L1).
The command UpBord01 (0.5) on the second line is a command to raise the lifting mechanism 123 (lifting table 121) by the height of the argument (0.5 mm).
The command DownBord02 (0.5) on the third line is a command to lower the lifting mechanism 124 (lifting table 122) by the height of the argument (0.5 mm). Thereby, the space which sets the metal powder 118 on the base | substrate 120 is ensured.

The command Squeeg on the fourth line is a command that the squeegee 116 drives. The squeegee 116 returns to the original position after carrying the metal powder 117 ascended from the lifting table 121 to the lifting table 122.

The command LaserBeam (L1) on the fifth line is a command for sintering the metal powder 118 by irradiating the laminating laser according to the hatched area of the laminating data 15 of the layer ID (L1) specified by the argument. is there.

The instructions on the 6th to 9th lines are the second sintering process in the laminating process on the first layer (L1), similar to the instructions on the 2nd to 5th lines. Of the metal powder 118 supplied by the command Squeeg in the nth layer, the portion not covered by the command LaserBeam (Ln) in the nth layer (unsintered) remains without being blown off even after the n + 1th layer. To do. Thereby, even if there is a space below the sintered layer, the sintered layer does not fall.
The command on the 35th to 38th lines is the first sintering process in the lamination process of the twelfth layer (L12). The command in the 39th to 42nd lines is the second sintering process in the laying process of the twelfth layer (L12).
As described above, as shown by reference numeral 312 in FIG. 9, the layered processing of the divided shaped objects is performed.

The command Wait (3) on the 43rd line is a command that waits for the next command to proceed for the time (3 seconds) specified by the argument. With this waiting time for cooling, as shown by reference numeral 313 in FIG.
The command UpBord01 (0.5) on the 44th line is a command to raise the elevating mechanism 123 upward by 0.5 mm.
The instruction Squeeg on the 45th line is an instruction for supplying the metal powder 117 onto the substrate 120, similarly to the instruction Squeeg on the fourth line. By this command, the metal powder is replenished to fill the gap corresponding to the volume reduction.

Note that the command Squeeg on the fourth line (powder replenishment for lamination) and the command Squeeg on the 45th line (powder replenishment for connection) may be distinguished as separate instructions. When distinguishing, as a powder replenishing mechanism for connection, the movable range of the squeegee 116 may be limited to the connection position (position 305 in FIG. 9).
Alternatively, instead of the squeegee 116, a powder replenishment mechanism for connection is newly provided, and the powder supply unit of the powder replenishment mechanism is moved to the upper part of the connection position, and then the powder is directly supplied from the upper part to the connection position May be dropped).
Furthermore, the connecting powder and the laminating powder may be different types of powders. Thereby, the strength of the connecting portion can be increased by replenishing the connecting portions with a powder that has increased strength after sintering.

The command JointLaserBeam (J12,5) on the 46th line divides the element by irradiating the connection laser according to the connection data 16 “J12” and the layer depth “5 mm” specified by the arguments. Is an instruction to connect the.
As a result, as shown by reference numeral 314 in FIG. 9, the modeled object is connected, so that the connected modeled object approaches the original shape before the division indicated by the stacking data 15 in FIG.
The command End on the 47th line is a command for informing the modeling apparatus 100 that the modeling process has ended.

Fig.11 (a) is a flowchart which shows the main process of modeling thing manufacture.
In the shape data storage process (S <b> 11), the control unit 10 stores the shape data of the modeled object 119 transmitted from the terminal 9 in the shape element data 11.
In the element dividing process (S12, details are shown in FIG. 11B), the element dividing unit 12 generates a tensile force due to thermal contraction for each element of the shape element data 11 in S11 as shown in FIG. Element division data 13 is created that indicates the division locations within the elements that are likely to occur.
In the layer data creation process (S13), as shown in FIGS. 6 and 7, the layer data creation unit 14 divides the shape element data 11 in accordance with the element division data 13, and the division data 15 Connection data 16 for connecting positions is created.

The control device 1 transmits at least one of the stacking data 15 and the connection data 16 shown in FIGS. 6 and 7 to the display connected to the control device 1 or the display of the terminal 9. May be displayed. Thereby, before starting the modeling process by the modeling apparatus 100, the user can grasp | ascertain the shape of the molded article to be modeled from now on.

In the command creation process (S14, details are shown in FIG. 12), the operation command creation unit 17 creates the operation command 18 from the stacking data 15 and the connection data 16 as illustrated in FIG.
In the command transmission process (S15), the operation command creation unit 17 transmits a series of commands in the operation command 18 of S14 to the modeling apparatus 100 in order from the top, so that the modeling object 119 along the operation command 18 is formed. 100.

FIG. 11B is a flowchart showing details of the element division processing (S12).
In the element subdivision process (S101), the element dividing unit 12 specifies, for each element of the shape element data 11, a region in which a free movement in the region is restricted and a tensile force due to thermal contraction is generated, and the specified region Based on the above, one element is subdivided (separated) into a plurality of elements. For example, in FIG. 3B, the element dividing unit 12 separates one element E5 into three elements (E51, E52, E53).

In the classification process (S102), the element dividing unit 12 classifies each element of the shape element data 11 into one of a connection unit, a link unit, and an element unit as described with reference to FIG.
In the aspect ratio calculation process (S103), the element dividing unit 12 calculates the aspect ratio of each element from the shape of each element of the shape element data 11, as described with reference to FIG.
When there are elements separated in S101, the element dividing unit 12 classifies the elements for each separated element (S102) and calculates an aspect ratio (S103).
In the divided token data generation process (S104), as shown in FIG. 5, the element dividing unit 12 generates a divided token as necessary for each element based on the classification result of S102 and the aspect ratio of S103. Install.

FIG. 12 is a flowchart showing details of the instruction creation process (S14). Hereinafter, FIG. 12 will be described with reference to the operation instruction 18 (to the line) in FIG.
In S201, the operation command creating unit 17 generates a command Initial on the first line.
S202 to S205 are loop processes for selecting the stacking data 15 created in the layer data creation process (S13) one by one in order from the lower layer (the layer having the lowest height). The layer currently selected in the loop will be described as a “selected layer”.

In S203, the operation command creating unit 17 generates a replenishment command (for example, UpBord01 in the second row, DownBord02 in the third row, Squeeg in the fourth row, etc.) for the selected layer.
In S <b> 204, the operation command creating unit 17 generates a laser irradiation command (such as LaserBeam in the fifth row) for stacking the metal powder 118 replenished in S <b> 203 for the selected layer.
As described with reference to FIG. 10, the combination of the processes in S203 and S204 may be executed a plurality of times. For example, when the lamination thickness of 0.5 mm can be formed by one sintering lamination process, and one layer is 1 mm, the combination of the processes of S203 and S204 may be executed for two sets.

In S211, if the division flag of the element division data 13 is “1”, the operation command creation unit 17 has a link with the connection data 16 as indicated by reference numeral 401 in FIG. to decide. If there is no link (S211, No), the process ends. If there is a link (S211, Yes), the process proceeds to S212.
In S212, the operation command creating unit 17 generates a connection preparation command (Wait on the 43rd line, UpBord01 on the 44th line, Squeeg on the 45th line).
In S213, the operation command creation unit 17 generates a connection laser irradiation command (command JointLaserBeam on the 46th line) and a command End on the 47th line, and ends the process.

In the present embodiment described above, a method for manufacturing a shaped article in which a plurality of sintered layers of a molding material powder-sintered using a laser beam or an electron beam are stacked and integrated is shown.
The modeling apparatus 100 sinters the molding material by irradiating a predetermined portion of the molding material layer with laser light to form a sintered layer. Furthermore, the modeling apparatus 100 coats a layer of the molding material on the sintered layer and irradiates a predetermined portion of the molding material with laser light to sinter the molding material so as to be integrated with the lower sintered layer. A formed sintered body is formed.
The modeling apparatus 100 manufactures an optical modeling object having a sintered body in which a plurality of sintered layers are laminated and integrated by repeating these sintering steps.

Therefore, the control device 1 divides the elements constituting the modeled object into two or more elements, and after each of the divided elements is powder-sintered and layered, modeling is performed to connect the divided elements by powder sintering. An operation instruction 18 for the apparatus 100 is created in advance. The control apparatus 1 specifies the division | segmentation location in a division | segmentation process from the aspect ratio of the element of a molded article, and the classification | category of an element.

Thereby, by dividing a certain element, the constraint between that element and another adjacent element is released, so that the tensile force due to thermal contraction does not have to be transmitted to another adjacent element. Furthermore, by connecting the divided portions anew, it is possible to create a composition having a desired shape and to ensure sufficient strength.
In addition, since the manufacturing method of the molded object of this embodiment does not specifically limit the sintered density of the sintered body, it requires a united volume, and has a complicated lattice structure or hollow structure constructed by a plurality of thin beams. It is also suitable for manufacturing shaped objects.

FIG. 13 is an explanatory view showing a stacking process in which two struts are connected by a beam as a comparative example.
At the start of sintering in FIG. 13A, the columns 201 and 202 are formed by irradiating the metal powder 200 on the substrate 204 with laser. Thereafter, in order to construct the beam 206 of FIG. 13B, laser is irradiated in the scanning direction 203 that reciprocates so as to connect the columns 201 and 202.
In the scanning direction 203, the beam spot diameter of 0.5 mm (the length in the Y-axis direction) can be sintered by one-way scanning in the reciprocation, so that the thickness of the beam 206 is 5 mm. In this case, it is sufficient to scan 5 reciprocations (= 5 mm ÷ 0.5 mm ÷ 2) while shifting in the Y-axis direction by 0.5 mm.
At the end of sintering in FIG. 13B, a beam 206 that connects the columns 201 and 202 is formed. However, due to the contraction of the beam 206 connecting the columns 201 and 202 in a short period of time in FIG. 13A, a tensile force is generated on the columns 201 and 202, resulting in residual stress and deformation of the formed product unintentionally. Sometimes it ends up.

Hereinafter, with reference to FIG. 14, the first to third features will be described in order as the main features of the shaped object 119 obtained by sintering the metal powder 118. Note that the features of the model 119 are not limited to the following three features. Further, the modeled object 119 may not include all the following three features, and may include only the first feature, for example.
Fig.14 (a) is a front view which shows an example of the molded article 119 different from FIG.9 (b).
The connection unit 501 created from the connection data 16 connects the left laminate unit 502 and the right laminate unit 503 created from the laminate data 15. That is, the connection part 501 is a connection element in the modeled object 119, and the stacked parts 502 and 503 are connected elements in the modeled object 119, respectively.
FIG.14 (b) is a front view which shows an example of the molded article 119 different from FIG.9 (b) and FIG.14 (a).
The connection unit 511 created from the connection data 16 connects the left laminate unit 512 and the right laminate unit 513 created from the laminate data 15.
Incidentally, the modeled object 119 in FIG. 14 has a smaller number of layers than the number of layers of the elements between the elements constituting the modeled object 119 (in this example, the layered portions 502, 503 / layered portions 512, 513). It can be said that the sintered metal element (in this example, the connection portion 501/511) is interposed (positioned between). This is the same in the example of FIG.

The connection portion 501 (the same applies to the connection portion 511) has the following characteristics.
The first feature is that the number of stacked layers of the connecting portion 501 is smaller than the number of stacked layers of the stacked portions 502 and 503. For example, the command JointLaserBeam (J12,5) on the 46th line in FIG. 10 is a command to sinter (at one time) five layers of connected elements as one layer of connected elements. The number of stacked layers is smaller than the number of stacked connection elements.
Note that the number of stacked connection portions 501 is not limited to one, and may be two or more. In addition, the number of lamination | stacking of the molded article 119 can be analyzed by observing the cross section of a molded article with a microscope.
Thereby, compared with the molded article in which the connection part 501 does not exist between the laminated part 502 and the laminated part 503, the molded article in which the connection part 501 is provided may be distorted due to the residual stress of the laminated parts 502 and 503. Since the distortion does not affect other adjacent elements, the strength and durability as a model can be improved.

The second feature is that at least one of the stacked portions 502 and 503 connected by the connecting portion 501 has a direction along the layer to be stacked (any direction on the XY plane, for example, the X-axis direction or the Y-axis direction). (Axial direction) is characterized by having a length of a predetermined length or more. As described with reference to FIG. 5, the element dividing unit 12 is a link unit in which the aspect ratio excluding the stacking direction (the Z-axis height direction) exceeds the threshold value 0.8 (that is, a length greater than or equal to a predetermined length). A split token is installed at a certain link part).
In other words, in order to sufficiently obtain the connection effect by the connection part 501, the connection part 501 is intensively arranged at a place where the size change (reduction) after sintering is larger than simply increasing the number of the connection parts 501. It is desirable to do. Thereby, by connecting between the stacked portions 502 and 503 after cooling by the connecting portion 501, distortion and deformation due to heat shrinkage are effectively prevented.

The third feature is that the connecting portion 501 connects the end surface of the stacked portion 502 and the end surface of the stacked portion 503. Therefore, the connection part 501 is formed by a butt welding process, for example.

On the other hand, in this embodiment, as described with reference to FIG. 9, by connecting the beams 303 c and 304 c with the connecting portion 305, it is not necessary to transmit the influence of the tensile force to the adjacent columns 301 and 302.

In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.
Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment. Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit.
Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor.

Information such as programs, tables, and files for realizing each function is stored in memory, a hard disk, a recording device such as an SSD (Solid State Drive), an IC (Integrated Circuit) card, an SD card, a DVD (Digital Versatile Disc), etc. Can be placed on any recording medium.
Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

DESCRIPTION OF SYMBOLS 1 Control apparatus 9 Terminal 10 Control part 11 Shape element data 12 Element division part 13 Element division data 14 Layer data creation part 15 Data for lamination | stacking 16 Connection data 17 Operation instruction creation part 18 Operation instruction 91-93 Connection line 100 Modeling apparatus DESCRIPTION OF SYMBOLS 110 Carbon dioxide laser oscillator 111 Collimator 112 Reference table 113 Galvano scanning device 114 Condensing lens 116 Squeegee 117,118 Metal powder (molding material)
119 Modeled objects (metal powder sintered parts)
120 Base 121, 122 Lifting table 123, 124 Lifting mechanism

Claims (11)

1. In order to produce a green body that forms a plurality of layers by repeating formation of a layer coated with a molding material and sintering of the layer, the coating and A lamination process that repeats sintering;
   And a connecting step of forming a connecting portion on the modeled object by sintering an unsintered part extending over the plurality of layers.
2. The method for manufacturing a shaped article according to claim 1, wherein, in the connecting step, the green portion is sintered after the molding material is replenished to the green portion extending over the plurality of layers.
3. The method for manufacturing a shaped article according to claim 2, wherein a predetermined cooling time is secured from the end of the laminating step to the start of the connecting step.
4. The shaped article according to claim 3, wherein the laser beam irradiation mechanism used for sintering in the laminating step and the laser beam irradiation mechanism used for sintering in the connecting step are used as separate mechanisms. Production method.
5. The laser beam irradiation mechanism used for sintering in the connection step is at least one of a laser output irradiation mechanism stronger than a laser beam irradiation mechanism used for sintering in the laminating step and a laser output period extended. It is one, The molded article manufacturing method of Claim 4 characterized by the above-mentioned.
6. An element dividing unit that reads solid shape data for each component of the modeled object, and identifies the component to be divided among the read components and the division position in the component;
   Slice the three-dimensional shape data of the modeled object into a plurality of layers, create layer data in which the modeled object exists in each sliced layer as a first sintered region,
   Of the created layer data, the location of the plurality of layers corresponding to the division position specified by the element division unit is corrected from the first sintered region to the unsintered region, and spans the plurality of layers corresponding to the division position. A layer data creation unit for adding a second sintered region for sintering the unsintered portion;
   According to the layer data created by the layer data creation unit, the first sintered region of each layer coated with the molding material is sintered, and then the second sintered region is sintered, thereby connecting to the modeled object. An operation command creating unit that creates an operation command for forming a part.
7. The element division unit is configured to divide a component in which a vertical aspect ratio or a horizontal aspect ratio exceeds a predetermined threshold and is constrained by a plurality of adjacent components among the components of the modeled object. The control device according to claim 6, wherein, for the component to be divided, a midpoint of a side whose aspect ratio exceeds a predetermined threshold is set as a division position.
8. The control device according to claim 6, wherein the layer data creation unit displays the created layer data on a display unit on a screen.
9. A layered product composed of layers of sintered metal powder,
   Connected elements constituting the modeled object are connected to each other by a sintered metal connection element having a number of stacked layers smaller than the number of stacked layers of the connected elements.
10. The modeled object according to claim 9, wherein at least one of the connected elements has a length in a direction along the layer to be stacked that is a predetermined length or more.
11. The shaped article according to claim 9 or 10, wherein the connecting element connects end faces of the connected elements.

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