JP2004001500A - Apparatus and method for sheet laminated molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable high strength laminated molding apparatus capable of carrying out high speed laminated molding, having little influence on a human body and an environment and having little delamination, and a method for laminated molding. <P>SOLUTION: The apparatus is characterized in that according to the instruction of a control device based on the data of a three-dimensional CAD system, there are provided on a work table a laying means by which a thermoplastic sheet is laminated and laid in turn, a cutting means by which the thermoplastic sheet is cut in turn and an energy irradiating means by which energy is irradiated in turn to the thermoplastic sheet laid on the work table to adhere the thermoplastic sheet reciprocally, and a three-dimensional object is molded as the laminated body of a sheet. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an additive manufacturing apparatus and an additive manufacturing method, and relates to an additive manufacturing apparatus and an additive manufacturing method for forming a three-dimensional object using a thermoplastic sheet.
[0002]
[Prior art]
As a conventional additive manufacturing apparatus for forming a three-dimensional object, for example, there is a so-called stereolithography apparatus described in Patent Document 1. This apparatus is an apparatus for making a three-dimensional object by curing and laminating a photocurable liquid resin with a laser beam.
In Patent Document 2, a layered manufacturing apparatus is known in which powdered resin is melted with a laser and bonded to be stacked.
On the other hand, as an additive manufacturing apparatus using a sheet, there is one described in Patent Document 3, for example. This apparatus forms a three-dimensional object by laminating sheets, and prepares a first plastic film cut into an effective area that constitutes a three-dimensional object and an unnecessary area that does not constitute a three-dimensional object. A second plastic film is supplied upward. At this time, a hot melt adhesive is applied to the second plastic film and is adhered by a heating roller. By repeating the above steps, a plastic film is sequentially laminated to form a three-dimensional object.
In addition to the above-mentioned adhesive method, a welding method is also conceivable. Conventionally, welding by a YAG laser or the like is known from Patent Document 4 or the like, but this technique closely contacts two members having different infrared absorptivity, and infrared A member with high transmittance is irradiated with a YAG laser or the like and heat-welded on the surface of the member with low infrared absorption.
[0003]
[Patent Document 1] Japanese Patent Publication No. 6-61847 [Patent Document 2] Japanese Patent Application Laid-Open No. 1-232027 [Patent Document 3] Japanese Patent Application Laid-Open No. 11-227053 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-218698 ]
[Problems to be solved by the invention]
However, the conventional additive manufacturing apparatus described above has the following problems.
First, the method of making a three-dimensional object by curing and laminating a photocurable liquid resin with a laser beam uses a photosensitive liquid resin, and thus has various restrictions on the installation environment of the apparatus. For example, it cannot be used in an environment with light that reacts, or the liquid resin itself is often irritating, and the resin is handled using protective equipment that protects the skin of the human body. There are many problems, such as the need to wear a mask to clean the uncured resin adhering to the surface with an organic solvent, and the management of the organic solvent. For this reason, the conventional apparatus requires a special working environment, and the worker has to be performed by a skilled person.
[0005]
Also, the method of layered molding from powdered resin also requires a dedicated space so that the powder does not scatter, and there is little effect on the human skin like the above liquid resin, but if it is sucked into the human body, the circulator There is concern that the system will be affected.
[0006]
In addition, the additive manufacturing apparatus using a sheet and a hot-melt adhesive has a problem that peeling between layers and original physical properties of the sheet are impaired due to the bonding with the adhesive. In addition, it is thought that there are fewer restrictions on the installation location compared to using liquid or powdered resin, but it can be used for the effects of chemical components contained in the adhesive on the human body and in clean environments such as offices. Is unsuitable. Furthermore, since the adhesive is applied, it is unsuitable for recycling a molded article that is no longer necessary after use or an auxiliary member generated during modeling.
[0007]
In addition, the conventional layered manufacturing method using welding using a YAG laser or the like cannot weld two or more layers, and cannot perform multilayer lamination.
[0008]
OBJECT OF THE INVENTION
In view of the problems of the prior art, the present invention aims to provide an additive manufacturing apparatus and additive manufacturing method capable of high-speed additive manufacturing and having little influence on the human body and the environment. To do.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, on the basis of data of a three-dimensional CAD system, in accordance with an instruction from a control device, mounting means for sequentially stacking and mounting thermoplastic sheets on a work table, and sequentially cutting the thermoplastic sheets A cutting means for performing the process, and an energy irradiation means for sequentially irradiating the thermoplastic sheet placed on the work table with energy to weld the thermoplastic sheets together, and forming a three-dimensional object as a laminate of the sheets. And
[0010]
In order to achieve the above object, according to the present invention, in an apparatus for modeling an object by stacking at least a plurality of layers based on data of a three-dimensional CAD system, the layers are thermoplastic sheets, and the data is Computer means for processing to create layer data including desired contour data for each layer, cutting means for cutting a thermoplastic sheet into a desired contour based on the contour data, and layer data processed by the computer And a placing means for positioning and placing the second thermoplastic sheet layer on the first thermoplastic sheet layer, and a heating means for heating the at least two thermoplastic sheets overlapped by the placing means. It is characterized by that.
[0011]
Further, by using the heating means as a heating furnace, it is possible to laminate and form multiple layers, and by using the heating means as a heating roller, the data creation is simple and high-speed bonding and welding are possible.
[0012]
In addition, the transparent sheet can be laminated in multiple layers by modifying the surface or surface portion so that the transmittance for part or all of the infrared region of the upper surface or surface portion of the thermoplastic sheet is reduced. Is possible.
[0013]
Moreover, it is possible to improve the adhesiveness between layers by using the material which provided the several air vent hole in the thermoplastic sheet.
[0014]
In addition, by adjusting means for adjusting the relative position with the thermoplastic sheet layer to a constant or desired distance, it is possible to perform highly stable welding in the Z-axis direction of energy irradiation and to perform lamination with less delamination.
[0015]
In addition, it is possible to perform accurate layered modeling by temporarily fixing the thermoplastic sheets at a plurality of locations and then performing continuous welding.
[0016]
Further, welding is performed on a part of the thermoplastic sheet surface, and by forming the energy irradiation path so that the welded portion and the non-welded portion are adjacent to each other, modeling can be performed in a short time.
[0017]
Further, the layer includes layers having different thicknesses, the layer includes a thermoplastic sheet layer group, and a sheet layer made of a material different from the thermoplastic sheet, or the sheets or the sheet layer group. Lamination molding with a higher degree of freedom is possible by welding, bonding or mechanically bonding each other.
[0018]
[Example 1]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an additive manufacturing apparatus according to the present invention.
In FIG. 1, 3 is a work table provided horizontally, and the work table 3 is supported by an elevating drive means (not shown) through an arm (not shown) so as to be raised and lowered. In this embodiment, the work table is installed horizontally, but it is not always necessary to install it horizontally. The lifting drive means (not shown) includes, for example, a servo motor and a ball screw mechanism, and moves the work table 3 at a predetermined position and moves it at a predetermined pitch (a pitch corresponding to the thickness of a layer to be described later). It can be returned to the position.
[0019]
The material sheet 1 is a thermoplastic sheet wound in a roll shape, and this sheet has a lower layer portion (work table 3 side) and an upper layer portion, and the lower layer portion is a part of the near infrared region or A material that absorbs all light, or that has been treated to absorb part or all of the light in the near infrared region, and the upper layer is a material that transmits part or all of the light in the near infrared region. It consists of
[0020]
Here, the layered manufacturing process of the said raw material sheet is shown to FIGS. 14-1 to 14-6. In each figure, 111 is a first thermoplastic sheet cut and placed on the work table 3 (not shown), and 112 is a second thermoplastic sheet placed on the first sheet 111. It is a thermoplastic sheet. First, the first sheet is cut into a desired contour on the table 3 by a CO2 laser or a cutter based on the cross-sectional data (FIG. 14-2). Next, the second sheet 112 is placed on the cut first sheet 111 (FIG. 14-3). Next, a transparent glass plate 113 is placed on the second sheet, and the sheet is brought into close contact (FIG. 14-4).
Next, based on the drawing pattern data or according to a predetermined scanning path, the YAG laser is irradiated onto the second sheet from above the glass plate to weld the first and second sheets 111 and 112. At this time, since the lower layer portion of the second sheet absorbs near infrared rays, heat is effectively generated only at the contact interface between the first and second sheets, and the first and second sheets 111 and 112 are welded. Is performed (FIG. 14-5). Next, the glass plate is moved from the second sheet, and the second sheet is cut into a desired contour by a CO2 laser or a cutter based on the cross-sectional data corresponding to the second sheet (FIG. 14-6). A desired layered object can be obtained by repeating such a series of steps.
[0021]
The unnecessary sheet portion 114 other than the layered product is easily removed after completion of the layering process by preliminarily cutting and perforating when cutting the desired contour of the sheet (FIGS. 14-2 and 14-6). can do.
Further, the unnecessary portion may be cut before the placement or after the placement.
[0022]
Reference numerals 4-1, 4-2, 5-1 and 5-2 denote laser scanning devices provided above the work table 3, which are constituted by a CO 2 laser part and a YAG or semiconductor laser part. The laser emitted from the laser source 4 or 5 is condensed on the sheet on the work table 3 through the optical system 8 or 9, and the laser beams 6 and 7 are scanned to perform high-precision scanning. Yes.
[0023]
A control device (not shown) is a control means including a CPU, a memory (RAM, ROM, etc.), and an input / output interface circuit, and a known three-dimensional CAD (Computer Aided Design) system is connected to the control device. This control device converts the shape data transmitted from the three-dimensional CAD system into cross-sectional data, and on the basis of the cross-sectional shape data, the elevating drive means, the laser scanning devices 4-1, 4-2, 5-1, and 5- 2 and the laser sources 4 and 5, and further controls the sheet feeding apparatus 2. Further, the control device is configured to control the laser scanning devices 4-1, 4-2, 5-1, and 5-2 corresponding to the drawing pattern data based on a predetermined control program stored in advance in the RAM, the ROM, or the like. A drive signal for the elevation drive means corresponding to the scanning drive signal and the layer thickness data is generated, a drive signal for the sheet feeding device 2 is further generated, and these signals are output at a predetermined timing.
[0024]
Next, the operation will be described together with the modeling work procedure in the present embodiment. First, when a three-dimensional object is designed in advance by a three-dimensional CAD system, a computer generates shape data of a plurality of cross sections with a minute interval for the object, and the data is used as a contour pattern of a plurality of sheet layers. And is transmitted to the control device as layer thickness data.
In the control device, the scanning amount in the scanning direction of the laser scanning devices 4-1, 4-2, 5-1, and 5-2 is calculated from the contour pattern data, and the lift driving means, the laser scanning devices 4-1, 4 and 4 are calculated. -2, 5-1 and 5-2, the driving timings of the laser sources 4 and 5 are set, and further the driving timings of the respective driving means of the sheet feeding apparatus 2 are set. These data can be stored in an appropriate storage means.
[0025]
In this embodiment, a laser scanning device capable of high-density scanning is used. However, in the present invention, the sheet can be welded and cut by applying a predetermined pattern of surface energy by masking. . Moreover, the sheet | seat does not necessarily need to be wound up by roll shape, and may use the sheet | seat cut by predetermined size. In the present embodiment, the reason why the sheet is rolled is that the means for transferring the sheet to the work table can be simplified.
[0026]
In addition, the thermoplastic sheet may be modified in order so that the transmittance with respect to part or all of the light in the infrared region on the upper surface or surface of the sheet is lowered.
[0027]
Examples of steps at that time are shown in FIGS. 13-1 to 13-8. In each figure, 101 is a first thermoplastic sheet cut and mounted on a work table 3 (not shown), and 102 is a second stacked and mounted on the first sheet 101. It is a thermoplastic sheet. First, the first sheet is cut into a desired contour on the table 3 by a CO2 laser or a cutter based on the cross-sectional data (FIG. 13-2). Next, the surface of the cut pattern portion is irradiated with a CO2 laser to modify the surface (white turbidity), thereby reducing the transmittance for part or all of the light in the infrared region (FIG. 13-3). . Next, the second sheet 102 is placed on the modified first sheet (FIG. 13-4). Next, a transparent glass plate 103 is placed on the second sheet (FIG. 13-5). Next, based on the drawing pattern data or according to a predetermined scanning path, the YAG laser is irradiated onto the second sheet from above the glass plate to weld the first and second sheets 101 and 102. At this time, since the transmittance of the upper surface portion of the first sheet with respect to part or all of the light in the infrared region is reduced, heat is effectively generated only at the contact boundary surface between the first and second sheets. The second sheets 101 and 102 are welded (FIG. 16-6). Next, the glass plate is moved from the second sheet, and the second sheet is cut into a desired contour by a CO2 laser or a cutter based on the cross-sectional data corresponding to the second sheet (FIG. 13-7).
Next, the surface of the cut pattern portion is irradiated with a CO2 laser to modify the surface (white turbidity), thereby reducing the transmittance for part or all of the light in the infrared region (FIG. 13-8). . A desired layered object can be obtained by repeating such a series of steps.
The unnecessary sheet portion 104 other than the layered object is easily removed after the lamination process is completed by cutting and perforating in advance when cutting the desired contour of the sheet (FIGS. 13-2 and 13-7). can do.
[0028]
Further, instead of the above-described modification, an infrared absorber may be applied to the lower side surface of the thermoplastic sheet, vapor deposition, adhesion, adhesion, or an infrared absorption layer may be attached, or the heat treated in such a manner. A plastic sheet material or a non-thermoplastic sheet material may be used.
Further, a plurality of air vent holes may be provided in the thermoplastic sheet to improve the adhesion between the layers. This is because if there is an air layer between the layers, poor welding is likely to occur, and air escape is improved.
[0029]
As described above, according to the above-described embodiment, it is possible to provide a stable high-strength additive manufacturing apparatus and additive manufacturing method capable of high-speed additive manufacturing, having little influence on the human body and the environment, and having less delamination. . Specifically, as a method of joining sheets, welding with YAG or a semiconductor laser and unnecessary portions are cut with a CO2 laser or a blade, effective portions are multilayered, a three-dimensional object is formed, and bonding strength is high. Lamination can be performed with little delamination.
[0030]
Moreover, it can replace with the laser as a means of joining of sheets, and it can be set as an inexpensive apparatus by crimping joining sheets using the adhesive material which does not have an environmental harm.
[0031]
In the above description, the case where a sheet that is welded with near infrared rays is used has been described. However, a sheet that is welded in response to ultraviolet rays may be used.
[0032]
[Example 2]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In FIG. 3, 10 is an additive manufacturing apparatus, and 11 is a CAD system that generates and stores solid shape data (FIG. 2). Solid shape data (CAD data) created and stored by the CAD system 11 is transmitted to the first computer 12.
The first computer 12 converts the received CAD data 24 into layer data 25 as shown in FIG. 7 by a known method using a machine tool, an optical modeling apparatus, or the like. The layer data 25 includes contour data and layer thickness data for each layer.
The layer data generated by the first computer is sent to the second computer means 13. Based on the contour data, the computer means 13 generates cutting laser 17-1 or cutting device path data, which will be described later, and scanning path data of the welding laser 17-2. The first and second computers 12 and 13 described above constitute computer means as a whole.
[0033]
14 is a work table provided horizontally, and this table 14 is configured in the same manner as the work table 3 of the first embodiment described above. The table 14 is controlled by the second computer so that the relative position in the Z direction between two lasers and a sheet material, which will be described later, is constant or a desired distance. The second computer and the table driving device constitute the adjusting means in the claims. This adjustment means preferably uses a position sensor (not shown) for detecting at least the position in the Z-axis direction of a first layer, which will be described later, and performs feedback control based on the position signal.
[0034]
Reference numeral 17-1 denotes a cutting laser device provided above the work table 14, and has the same configuration as the laser scanning devices 4-1 and 4-2 of the first embodiment described above. The cutting laser device 17-1 cuts a thermoplastic sheet material described later based on the route data of the second computer. On the other hand, 17-2 is a welding laser device provided above the work table 14, and has the same configuration as the laser scanning devices 5-1, 5-2 of the first embodiment described above. The welding laser device 17-2 performs welding of a thermoplastic sheet material, which will be described later, based on scanning path data of the second computer. These laser devices 17-1 and 17-2 may be drive devices having XYZ orthogonal coordinates. The sheet material may be cut using a mechanical cutter device. Reference numeral 18 denotes a sheet feeding device, and 19 denotes a sheet winding device. These are configured in the same manner as the sheet feeding device and the sheet winding device of the first embodiment described above.
[0035]
The sheet 15 is a sheet wound up in a roll shape. The sheet 15 is sequentially pulled out by the sheet supply device 18 and precisely positioned on the work table 14 to explain the sheet reforming process of the first embodiment. FIGS. -8, the sheet is sequentially pressed from above by the glass pressing device 16, the contour is laser welded by the welding laser device 17-2, the necessary portions are scanned and welded, and the cutting laser device 17- Unnecessary portions are cut by 1, and the remaining material sheet is collected by the sheet winding device 19. In this series of steps, modification may be performed in the same manner as in the first embodiment, or an infrared absorber may be applied. FIG.
[0036]
The sheet supply device 18, the glass pressing device 16, the work table 14, the laser devices 17-1 and 17-2, and the sheet take-up device 19 are operated by the second computer so as to repeat this series of operations and perform layered modeling of sheets. To be controlled.
[0037]
Next, data generation for additive manufacturing will be described. 7- (1) generated and stored by the CAD system is transferred to the first computer, and the transferred data is sliced by the first computer as shown in FIG. 7- (2). Convert to shape data for each layer.
Next, the shape data is transferred to the second computer, and the transferred data includes the frame region 21 of the sheet material 15, the laser cutting and welding locus 20 as shown in FIG. Convert to layer data. The laser scanning locus at that time will be described in detail with reference to FIG. In FIG. 6, A is a contour representing a cross-sectional shape of a target modeled object, that is, a cutting trajectory, B is a welding trajectory that scans a laser in a solid region, and C is easy to remove as an unnecessary part of a sheet material in a post-modeling process. A cut locus, D, is a temporary attachment locus (point) for temporarily attaching the layers to each other.
[0038]
Next, additive manufacturing will be described. As shown in FIG. 5, a base sheet (lowermost layer) 22 is fixed on the work table 14 by, for example, a double-sided adhesive tape 23 before modeling. Next, the sheet winding device 19 and the supply device 18 are operated to position and place the first layer sheet on the base sheet 22, and the glass plate 16 (FIG. 3) is placed on the first layer sheet. Hold down. Next, the first layer sheet is irradiated with laser based on the temporary fixing data D, and the first layer is temporarily fixed and welded to the base sheet. Then, if necessary, welding is performed based on the data A. Thereafter, the glass plate is removed from the first layer sheet on the work table, and the first layer sheet is cut with a laser beam based on the locus data A and the cut break data C of the first layer.
[0039]
Next, the table is further lowered, the sheet winding device and the feeding device are operated, the second layer sheet is positioned and placed on the first layer sheet, and the glass plate is placed on the second layer sheet and pressed. . Then, the second layer sheet is irradiated with laser based on the temporary fixing data D, and the second layer is temporarily fixed and welded to the first layer sheet. Then, if necessary, welding is performed based on the data A. Thereafter, the glass plate is removed from the second layer sheet on the work table, and the second layer sheet is cut with a laser beam based on the locus data A and the cut break data C of the second layer. A desired shaped object can be created by repeating such a lamination process.
[0040]
Moreover, as shown in FIG. 8, when the modeling includes layers having different thicknesses in the stack, before the layers having different thicknesses are supplied from another supply device and already stacked. Welded, glued or mechanically bonded to the layers.
In addition, for joining with the ones that have been layered in advance or with other parts, as shown in FIG. 9, they are mechanically joined with bolts and nuts 26 or the like, or are joined by adhesion.
[0041]
In the present invention, different materials can be layered as shown in FIG. In that case, a layer of a different material is supplied from another supply device, which is welded, glued or mechanically bonded to the previous layer already laminated.
[0042]
In the present invention, a heat source other than a laser, such as a heating furnace or a heating roller, can be used as a welding heat source. In the case of using a heating furnace, each layer is temporarily fixed with a laser or an adhesive, and then, as shown in FIG. 11, the temporary fixing layered object is heated in the heating furnace 27, and each boundary of the layered object is Weld the layer surfaces. In this case, since the bonding operation using a laser or an adhesive is only a temporary fixing operation, the modeling time can be shortened.
When a heating roller is used, as shown in FIG. 12, the heating means for welding is the heating roller 28, and the other configurations are the same as those in the second embodiment. In this case, reliable welding at a desired pressure and heating temperature and higher-speed layered modeling are possible.
[0043]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an additive manufacturing apparatus and additive manufacturing method capable of high-speed additive manufacturing and having little influence on the human body and the environment.
[Brief description of the drawings]
FIG. 1 shows an embodiment of an additive manufacturing apparatus according to the present invention.
FIG. 2 shows a flow of layered data in the layered manufacturing apparatus of FIG.
FIG. 3 shows another embodiment of an additive manufacturing apparatus according to the present invention.
FIG. 4 shows cutting of a supply sheet material by laser irradiation.
FIG. 5 is a diagram illustrating the start of stacking.
FIG. 6 shows each region of a cross-sectional shape of a modeled object.
FIG. 7 shows an example of a general layered object.
FIG. 8 shows a shaped object in which layers having different thicknesses are stacked.
FIG. 9 shows a shaped object laminated by mechanical bonding.
FIG. 10 shows a shaped object in which layers of different materials are laminated.
FIG. 11 shows a complete welding process after additive manufacturing by a heating furnace.
FIG. 12 shows heat welding by a heating roller.
FIG. 13 shows a thermoplastic resin sheet reforming process and an additive manufacturing process.
FIG. 14 shows a layered manufacturing process of a thermoplastic resin sheet.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Material sheet 2 Sheet supply apparatus 3 Work table 4, 5 Laser source 4-1, 4-2 Laser scanning apparatus 5-1, 5-2 Laser scanning apparatus 6, 7 Laser beam 8, 9 Optical system 10 Laminate modeling apparatus 11 CAD system 12 1st computer 13 2nd computer 14 Work table 15 Sheet material 16 Glass pressing device 17-1 Cutting laser device 17-2 Welding laser device 18 Sheet supply device 19 Sheet winding device

Claims (16)

Based on the data of the three-dimensional CAD system, in accordance with an instruction from the control device, the placing means for sequentially stacking and placing the thermoplastic sheets on the work table, the cutting means for sequentially cutting the thermoplastic sheets, and the placing on the work table An additive manufacturing apparatus comprising: energy irradiation means for sequentially irradiating energy to the thermoplastic sheet thus formed to weld the thermoplastic sheets together, and forming a three-dimensional object as a laminate of the sheets. Based on the data of the three-dimensional CAD system, in accordance with instructions from the control device, a placing process for sequentially stacking and placing thermoplastic sheets on the work table, a cutting process for sequentially cutting the thermoplastic sheets, and placing on the work table And an energy irradiation step of sequentially irradiating the thermoplastic sheet with energy to weld the thermoplastic sheets together, and forming a three-dimensional object as a laminate of the sheets. In an apparatus for modeling an object by laminating at least a plurality of layers based on data of a three-dimensional CAD system, the layer is a thermoplastic sheet, and energy irradiation means for irradiating the sheet with energy, and the data Computer means for processing to generate layer data including desired contour data of each layer and desired irradiation path data of the energy irradiation means, and cutting means for cutting the thermoplastic sheet into a desired contour based on the contour data And a placement means for positioning and placing the second thermoplastic sheet layer on the first thermoplastic sheet layer based on the layer data processed by the computer, and a second thermoplastic sheet based on the path data The energy irradiating means is scanned to irradiate the layer with the energy and to weld the first and second thermoplastic sheet layers to each other at the contact surfaces. Layered manufacturing apparatus characterized by comprising: a means. In a method of forming an object by stacking at least a plurality of layers based on data of a three-dimensional CAD system, the layer is a thermoplastic sheet, and an energy irradiation step of irradiating the sheet with energy, and the data A data generation step of processing to create layer data including desired contour data of each layer and a desired irradiation path data of the energy irradiation step, and cutting to cut the thermoplastic sheet into a desired contour based on the contour data And a placement step of positioning and placing the second thermoplastic sheet layer on the first thermoplastic sheet layer based on the layer data created in the data creation step, and based on the path data Irradiating the second thermoplastic sheet layer with the energy and irradiating the energy such that the first and second thermoplastic sheet layers are welded to each other. Layered manufacturing method according to claim. In an apparatus for forming an object by stacking at least a plurality of layers based on data of a three-dimensional CAD system, the layers are thermoplastic sheets, and the data is processed to include desired contour data of each layer Computer means for creating layer data; cutting means for cutting the thermoplastic sheet into a desired contour based on the contour data; and a second thermoplastic sheet layer on the first thermoplastic sheet layer based on the layer data processed by the computer. An additive manufacturing apparatus comprising: mounting means for positioning and mounting the thermoplastic sheet layer; and heating means for heating at least two thermoplastic sheets overlapped by the mounting means. 6. The additive manufacturing apparatus according to claim 5, wherein the heating means is a heating furnace or a heating roller. 5. The method according to claim 2, further comprising a reforming step of sequentially reforming the surface or surface portion so that the infrared transmittance of the upper surface or surface portion of the thermoplastic sheet placed above is lowered. The additive manufacturing method. 5. The additive manufacturing method according to claim 2, wherein the modification is performed by energy irradiation means. 6. The additive manufacturing apparatus according to claim 1, wherein an infrared absorber is applied, vapor-deposited, adhered, adhered, or an infrared-absorbing layer is attached to a lower surface of the thermoplastic sheet. The additive manufacturing apparatus according to claim 1, wherein a plurality of air vent holes are provided in the thermoplastic sheet. 4. The additive manufacturing apparatus according to claim 3, further comprising an adjusting unit that adjusts a relative position between the energy irradiating unit and the thermoplastic sheet layer to a constant or desired distance based on the layer data. The route includes first and second route data, the first route data is data for temporarily fixing the first and second sheets at a plurality of locations, and the second route data is at least continuous welding. The additive manufacturing apparatus according to claim 3, wherein the layered manufacturing apparatus is data for a region. 4. The additive manufacturing apparatus according to claim 3, wherein the welding is performed on a part of the thermoplastic sheet surface, and the irradiation path is formed so that the welded portion and the non-welded portion are adjacent to each other. The additive manufacturing apparatus according to claim 1, wherein the layers include layers having different thicknesses. The additive manufacturing apparatus according to claim 1, wherein the layer includes a thermoplastic sheet layer group and a sheet layer made of a material different from the thermoplastic sheet. 16. The additive manufacturing apparatus according to claim 15, wherein the thermoplastic sheet layer group and a sheet layer made of a material different from the thermoplastic sheet are welded, bonded, or mechanically coupled.

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