JP2018016005A - Molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which lamination deficiency is caused by the generation of a region not contacting with a lamination surface when the lamination surface is not parallel with a surface facing to the lamination surface.SOLUTION: The molding apparatus producing a three-dimensional article by laminating material layers includes a layer-forming part for forming the material layer, and a lamination part for laminating the material layer on a lamination surface, where the lamination part includes a stage on which the material layer is laminated, and a facing member for sandwiching the material layer with the stage for pressing, and an elastic member, where the elastic member is provided on the stage or the facing member, and the stage or the facing member presses the material layer through the elastic member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a modeling apparatus that models a three-dimensional object using a layered modeling method.

  In recent years, three-dimensional modeling technology called additive manufacturing (AM) has attracted attention. In AM technology, slice data is generated by slicing shape data of a three-dimensional model, a plurality of material layers made of a modeling material are formed based on the slice data, and the plurality of material layers are sequentially stacked and fixed. Therefore, it is a technology for modeling a three-dimensional object.

  In Patent Document 1, a powder image is formed on an intermediate carrier by electrophotography, and the powder image on the intermediate carrier is sandwiched between a stage surface and a planar heater and heated / cooled. A modeling apparatus for transferring a powder image from an intermediate carrier to a laminated surface is disclosed. Furthermore, in order to suppress a decrease in transfer efficiency of the powder image to the laminated surface due to minute unevenness on the stage surface, a polyimide base material, an elastic layer made of 300 μm-thick silicone rubber, and a mold release made of a fluororesin The use of an intermediate carrier consisting of layers is described.

JP-T 8-511217

  When the material layer is transported to a position facing the stage by the intermediate carrier, the material is heated by the heater unit until the material layer is melted or softened, and then cooled, so that the three-dimensional object being shaped on the stage or the stage is cooled. Laminated on top. At this time, since the heater unit heats / cools the material layer via the intermediate carrier, the temperature of the intermediate carrier is raised to a temperature higher than the temperature at which the material layer melts or softens each time the layers are laminated, or the temperature at which the material layer solidifies. It is necessary to let it cool down.

  However, the intermediate carrier of Patent Document 1 has an elastic layer made of 300 μm-thick silicone rubber, and the thermal conductivity of silicone rubber is as low as about 0.2 W / m · K. For this reason, the time required to raise or heat the material layer to the temperature required for lamination becomes long, and the lamination time per layer, and thus the modeling time per three-dimensional object, becomes very long.

  An object of this invention is to provide the modeling apparatus which can suppress generation | occurrence | production of a lamination | stacking defect, and can suppress that modeling time per solid thing becomes long.

Specifically, it is a modeling apparatus that stacks material layers formed based on slice data of a three-dimensional model to produce a three-dimensional object, and includes a layer forming unit that forms the material layer, and a stacked surface of the material layer And a laminated portion that is laminated on top,
The laminated portion includes a stage on which the material layer is laminated, an opposing member that pressurizes the material layer between the stage, and an elastic member.
The elastic member is installed on the stage or the opposing member;
The stage or the opposing member pressurizes the material layer through the elastic member.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing generation | occurrence | production of a stacking fault, it can provide the modeling apparatus which can suppress that modeling time per solid thing becomes long.

It is a figure which shows the outline of a structure of the modeling apparatus which concerns on this invention. It is a figure explaining the subject of this invention. It is a figure which shows an example of the process in which the material layer is laminated and fixed to a lamination surface in the modeling apparatus which concerns on this invention. It is a figure which shows the structural example of the three-dimensional modeling apparatus which concerns on 1st Embodiment. It is a flowchart which shows the operation | movement sequence of the three-dimensional model | molding apparatus which concerns on 1st Embodiment. It is a figure which shows the outline of a structure in the lamination position of the modeling apparatus which concerns on 2nd Embodiment. It is a figure which shows the outline of a structure in the lamination position of the modeling apparatus which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described with reference to the drawings. Unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and various control procedures, control parameters, target values, etc. of each member described in the following embodiments of the present invention are as follows. It is not intended to limit the scope only to them.

  First, with reference to FIG. 1, the structure of the modeling apparatus which concerns on this invention is demonstrated easily. FIG. 1 is a diagram schematically illustrating the overall configuration of the modeling apparatus.

  The modeling apparatus generally includes a control unit (also referred to as a control unit) U1, a layer formation unit (layer formation unit) U2, and a lamination unit (lamination unit) U3.

  The control unit U1 is a unit that performs processing for generating slice data (cross-section data) of a plurality of layers from the three-dimensional shape data of the modeling target, control of each unit of the modeling apparatus, and the like.

  The layer forming unit U2 includes a first material image forming unit 10a, a second material image forming unit 10b, and a conveyance body 20. The first material image forming unit 10a can form an image made of the first modeling material, and the second material image forming unit 10b can form an image made of the second modeling material. In FIG. 1, an endless belt stretched around a plurality of rollers 110 and 111 is employed as the transport body 20. For example, the roller 110 is a driving roller, the roller 111 is a driven roller, the operation of the driving roller 110 is controlled by the driving unit 112, and the operation of the transport body 20 is also controlled. The conveyance body 20 is not limited to a belt-like one, and may be configured to carry and carry a material layer with a plate-like member.

  When the control signal based on the slice data is transmitted from the control unit U1 to the layer forming unit U2, a material layer corresponding to the cross section of the modeling target is formed in the layer forming unit U2. Specifically, an image (material image) for each modeling material specified by the slice data is formed by the first material image forming unit 10a and / or the second material image forming unit 10b. The material images formed by the first and second material image forming units 10a and 10b are transferred to the conveyance body 20. At this time, by controlling the transfer positions of the two material images, the material images on the conveyance body 20 are transferred. Thus, a material layer corresponding to one cross section of the modeling object is formed. The transferred material layer is conveyed by the conveyance body 20 to the stacking unit U3.

  The stacked unit U3 is a unit in which a plurality of material layers formed in the layer forming unit U2 are sequentially stacked and fixed (hereinafter referred to as stacked fixing) to produce a three-dimensional object.

  As illustrated in FIG. 1, the stacked unit U <b> 3 includes a facing member 33, a stage 34, and an elastic member 35.

  In the stacking unit U3, the material layer 36 transported to the stacking position by the transport body 20 is sandwiched between the stacking surface of the stage 34 or the stacking surface of the three-dimensional object being modeled on the stage 34 and the opposing member 33. The material layer 36 and the laminated surface are brought into contact with each other. While maintaining this state, pressurization and heating are performed, and the material layer 36 is laminated and fixed on the lamination surface. During lamination, the material layer 36 and the laminated surface may be brought into contact with each other by moving the stage 34 up and down while the conveyance belt 20 is stopped. However, the conveyance body 20 and the stage 34 are moved synchronously. However, the material layer 36 and the laminated surface may be brought into contact with each other.

  Next, problems to be solved by the present invention will be described in detail.

  As described above, the material layer is transferred from the conveying body 20 onto the lamination surface by being pressed and heated while being sandwiched between the facing member 33 and the stage 34 of the lamination unit U3. Is done. At this time, the parallelism between the pressing surface of the facing member 33 and the laminated surface of the stage 34 becomes important.

  FIG. 2 illustrates a problem that occurs when the material layer 36 is transferred to the stacked surface of the three-dimensional object (modeled object) 37 being modeled when the pressing surface of the opposing member 33 and the stacked surface of the stage 34 are not parallel. It is exaggerated for easy understanding.

  When the material layer 36 is transported to the stacking position by the transport body 20, for example, the facing member 33 is lowered to a position in contact with the transport body 20, and the stage 34 is lifted (FIG. 2A). The distance between the stage 34 and the opposing member 33 is reduced, and both come into contact with each other through the material layer 36 and the transport body 20. At this time, since the opposing surfaces of the opposing member 33 and the stage 34 are made of a material that does not deform significantly, such as metal, the stage 34 and the opposing member 33 can only partially contact each other (FIG. 2B). Therefore, in the region where the stage 34 and the facing member 33 do not contact, the heat from the facing member 33 is not sufficiently transmitted to the material layer 36, so that the material layer 36 is not easily melted and stacking failure is likely to occur. Further, only a part of the three-dimensional object and the material layer is pressurized, and the region where the material layer is not pressurized remains on the conveying body 20 without being transferred to the modeling surface, resulting in poor stacking (FIG. 2C).

  It is sufficient if the pressing surface of the facing member 33 and the laminated surface of the stage 34 can be installed in parallel, but in reality, an error of about 100 μm occurs between the facing surfaces of the facing member 33 and the stage 34. Conceivable. Therefore, as in Patent Document 1, when an elastic member made of silicone rubber having an appropriate film thickness according to the parallelism is provided on the transport body 20, an error in the parallelism between the opposing member 33 and the stage 34 is absorbed by the elastic layer. can do.

  By the way, although the conveyance body 20 is heated more than the temperature which a material layer softens or fuse | melts in a lamination position, it is not necessarily positively heated except a lamination position. Therefore, if an elastic member is provided on the transport body 20 as in Patent Document 1, it is necessary to raise the temperature of the transport body 20 to a predetermined temperature every time it is stacked. When an elastic member made of silicone rubber having a thickness of several hundreds μm is provided on the transport body 20, the material layer is heated through the silicone rubber at the time of lamination, but the thermal conductivity of the silicone rubber is 0.00. As low as 2 W / m · K. Therefore, if the temperature of the silicone rubber is raised to a desired temperature every time it is laminated, it takes a long time to form one three-dimensional object. .

  Therefore, in the modeling apparatus according to the present invention, an elastic member for absorbing a parallelism error between the facing member 33 and the stage 34 is provided on at least one of the facing member 33 or the stage 34. When the elastic member is provided on the opposing member 33, the elastic member having a low thermal conductivity does not need to be heated every time it is laminated because the elastic member is placed in a heated state together with the opposing member 33 during modeling. Further, when the elastic member is provided on the stage 34, since there is no elastic member between the material layer and the heating means, the temperature rise of the material layer is not hindered.

  FIG. 3 shows an example of a process in which the material layer 36 is laminated and fixed to the laminated surface of the three-dimensional object (modeled object) 37 being modeled using the modeling apparatus according to the present invention. In FIG. 3, the elastic member 35 is disposed on the surface of the facing member 33 that faces the stacked surface of the stage 34. As in FIG. 2, the pressing surface of the facing member 33 and the stacked surface of the stage 34 are not parallel.

  When the material layer 36 is transported to the stacking position by the transport body 20, the facing member 33 is lowered to a position where it comes into contact with the transport body 20, and the stage 34 is lifted (FIG. 3A). The distance between the stage 34 and the facing member 33 is reduced, and the material layer 36 and the conveying belt 20 are in contact with each other through the entire surface (FIG. 3B). In FIG. 2B, since the facing surface of the facing member 33 and the stage 34 is not greatly deformed, the contact area between the stage 34 and the facing member 33 cannot be increased. However, in the case of FIG. 3, the elastic member 35 is deformed so as to absorb the error in parallelism, so that the stage 34 and the opposing member 33 can be brought into full contact with each other. Therefore, heat is sufficiently transmitted to the entire surfaces of the three-dimensional object 37 and the material layer 36, and the material layer 36 can be transferred to the three-dimensional object 37 without remaining on the transport belt 20 (FIG. 3C). .

  The elastic member 35 is particularly preferably a sheet-like member, but may be a component member provided by being divided into a plurality of regions.

  As the elastic member 35, a member of 60 or less can be suitably used with a type D durometer conforming to JISK6253. Particularly, a member of 90 or less is desirable in a type A durometer conforming to JISK6253, and a member of 50 or less is particularly desirable in a type A durometer conforming to JISK6253. For example, a material selected from chloroprene rubber, nitrile rubber, natural rubber, ethylene / propylene rubber, fluorine rubber, urethane rubber, and silicone rubber, or a rubber sponge obtained by foaming each rubber material may be used. Further, a combination of a plurality of these rubbers and rubber sponges may be used.

  The thickness in the direction perpendicular to the laminated surface of the elastic member 35 is preferably 0.1 mm or more and 2 mm or less. By setting the thickness to 0.1 mm or more, it is possible to absorb a shift in parallelism between the facing member 33 and the stage 34. Further, by setting the thickness of the elastic member 35 to 2 mm or less, an increase in the heat capacity of the elastic member 35 can be suppressed, and the elastic member 35 can easily follow the temperature change of the opposing member. As a result, the temperature change of the opposing member can be transmitted to the material layer in a short time.

  Hereinafter, embodiments according to the present invention will be specifically described. However, a plurality of configurations described in these embodiments may be employed in combination.

<First Embodiment>
[Overall configuration of modeling equipment]
A configuration of a modeling system including the modeling apparatus according to the first embodiment will be described with a specific example. In this embodiment, a method of producing a three-dimensional object by laminating a material layer in which a particulate modeling material is arranged two-dimensionally is used. However, a material layer formed using a liquid modeling material is laminated. A method of producing a three-dimensional object may be used.

  The structural example of the modeling apparatus which concerns on 1st Embodiment is shown in FIG. The modeling apparatus includes an outline, a control unit U1, a layer forming unit U2, and a stacking unit U3. The control unit U1 is a unit that performs processing for generating slice data (cross-section data) of a plurality of layers from the three-dimensional shape data of the modeling target, control of each unit of the modeling apparatus, and the like. The layer forming unit U2 is a unit that forms a material layer made of a modeling material using an electrophotographic process. And the lamination | stacking part U3 is a unit which forms a three-dimensional object by laminating | stacking the several material layer formed in the layer formation part U2 on a stage in order.

  U1 to U3 may be unitized by storing each part in a separate casing, or may be collectively stored in one casing. The configuration of U1 to U3 as a unit allows easy combination and replacement of units according to the use of the 3D modeling device, required performance, materials to be used, installation space, failure, etc. There is an advantage that the degree and convenience can be improved. On the other hand, the configuration in which U1 to U3 are collectively housed in one housing has advantages such as downsizing of the entire device and cost reduction. Note that the unit configuration in FIG. 4 is merely an example, and other configurations may be adopted. For example, the layer forming unit U2 may form a material layer using an inkjet process.

  In the modeling apparatus of the present embodiment, the transport body 20 in FIG. 1 is constituted by a first transport body (transport belt) 11 and a second transport body (transport belt) 30. The elastic member 35 is disposed between the facing member 33 and the second conveyance belt 30. By separating the transport body on which the material image is transferred in the layer forming unit U2 and the transport body that transfers the material layer to the stacking surface in the stacking unit U3, the heat of the stacking unit affects the layer forming unit U2. There is an advantage that it can be reduced.

[Controller unit]
The configuration of the control unit U1 will be described. The control unit U1 includes a three-dimensional model data input unit U10, a data generation unit U11, a layer formation control unit U12, and a stacking control unit U13.

  The 3D model data input unit U10 has a function of receiving 3D shape data and material information of a 3D model that is a modeling pair from an external device (for example, a personal computer or the like). As the three-dimensional shape data, data created and output by a three-dimensional CAD, a three-dimensional modeler, a three-dimensional scanner, or the like can be used. Although the file format is not ask | required, for example, an STL (Stereolithography) file format can be used preferably.

  The data generation unit U11 calculates a cross-sectional shape for each layer by slicing a three-dimensional model represented by the three-dimensional shape data at a predetermined pitch, and forms a material layer in the layer forming unit U2 based on the cross-sectional shape. It has a function of generating image data to be used (referred to as slice data). The image data is associated with the material information of the three-dimensional model, and it can be given to the layer forming unit U2 which modeling material is to be arranged. Further, the data generation unit U11 analyzes the three-dimensional shape data or slice data, determines the presence or absence of an overhang portion (a portion where the space immediately below is a space), and outputs data for arranging the support material as necessary. Generate the slice data that contains it.

  The three-dimensional model data input unit U10 and the data generation unit U11 may not include the modeling apparatus as long as data for forming a material layer can be obtained by the layer formation control unit U12. For example, the control unit U1 may include a receiving unit instead of the three-dimensional model data input unit U10 and the data generation unit U11, and acquire slice data generated outside via a network line. .

  As will be described in detail later, the layer forming unit U2 of the present embodiment can form a material layer using a plurality of types of materials. Therefore, the slice data includes data corresponding to each material image. As the file format of the slice data, for example, multi-value image data (each value represents a material type) or multi-plane image data (each plane corresponds to a material type) can be used.

  The layer formation control unit U12 has a function of controlling the material layer formation process in the layer formation unit U2 based on the slice data. Further, the stacking control unit U13 has a function of controlling the stacking process in the stacking unit U3. Specific control contents in each part will be described later.

  Although not shown, the control unit U1 includes an operation unit, a display unit, and a storage unit. The operation unit is a function that receives an instruction from the user. For example, power on / off, various device settings, operation instructions, and the like can be input. The display unit has a function of presenting information to the user, and can present various setting screens, error messages, operating conditions, and the like, for example. The storage unit has a function of storing three-dimensional shape data, slice data, various setting values, and the like.

  The control unit U1 is configured in hardware by a computer having a CPU (Central Processing Unit), a memory, an auxiliary storage device (hard disk, flash memory, etc.), an input device, a display device, and various I / Fs. Can do. Each of the functions U10 to U13 described above is realized by the CPU reading and executing a program stored in an auxiliary storage device or the like and controlling necessary devices. However, some or all of the functions described above may be configured by a circuit such as an ASIC or FPGA, or may be executed by another computer using a technique such as cloud computing or grid computing.

[Layer formation part]
The layer forming unit U2 is a unit that forms a material image made of a modeling material using an electrophotographic process. The electrophotographic process is a technique for forming a desired image by a series of processes in which a photoreceptor is charged, a latent image is formed by exposure, and developer particles are attached to form a developer image.

  As shown in FIG. 4, the layer forming unit U2 includes a first material image forming unit 10a, a second material image forming unit 10b, a first transport belt 11, a belt cleaning device 12, and an image detection sensor 13. Yes. The first material image forming unit 10a is a material image forming unit for forming a material layer using the first modeling material Ma, and includes an image carrier 100a, a charging device 101a, an exposure device 102a, a developing device 103a, A transfer device 104a and a cleaning device 105a are included. The second material image forming unit 10b has the same configuration as that of the first material image forming unit 10a.

  These material image forming units 10 a and 10 b are arranged along the surface of the first conveying belt 11. In FIG. 4, the material image forming unit 10a of the structural material is arranged on the upstream side in the transport direction, but the arrangement order of the material image forming units is not limited. Further, the number of material image forming units may be more than two, and can be appropriately increased according to the type of modeling material to be used. For example, when four material image forming portions are provided, image formation can be performed with four types of structural materials, or image formation can be performed with three types of structural materials and one type of support material. By combining multiple types of materials with different physical properties such as material, color, and hardness, there are many variations of the three-dimensional model to be generated. Such excellent extensibility can be said to be one of the advantages of a three-dimensional modeling apparatus using an electrophotographic process.

  Hereinafter, the configuration of each part of the layer forming unit U2 will be described in detail. However, in the description common to the material image forming units 10a to 10d, the subscripts a to d of the reference numerals of the constituent members are omitted and described as the material image forming unit 10, the image carrier 100, and the like.

(Image carrier)
The image carrier 100 is a member for carrying an electrostatic latent image. Here, a photosensitive drum in which a photoconductive layer having photoconductivity is formed on the outer peripheral surface of a metal cylinder such as aluminum is used. As the photoconductor, an organic photoconductor (OPC), an amorphous silicon photoconductor, a selenium photoconductor, or the like can be used, and the type of the photoconductor may be appropriately selected according to the use and required performance of the three-dimensional modeling apparatus. The image carrier 100 is rotatably supported by a frame (not shown), and rotates at a constant speed clockwise in the drawing by a motor (not shown) during image formation.

(Charging device)
The charging device 101 is charging means for uniformly charging the surface of the image carrier 100. In this embodiment, a non-contact charging method using corona discharge is used, but other charging methods such as a roller charging method in which a charging roller is brought into contact with the surface of the image carrier 100 may be used.

(Exposure equipment)
The exposure apparatus 102 is an exposure unit that exposes the image carrier 100 according to image information (slice data) and forms an electrostatic latent image on the surface of the image carrier 100. The exposure apparatus 102 includes, for example, a light source such as a semiconductor laser or a light emitting diode, a scanning mechanism including a polygon mirror that rotates at high speed, and an optical member such as an imaging lens.

(Developer)
The developing device 103 is a developing unit that visualizes an electrostatic latent image by supplying a developer (here, particles of a structural material or a support material) to the image carrier 100 (in this specification, by a developer). Visualized image is called material image). The developing device 103 can employ the same configuration as the developing device used in a two-dimensional printer.

  The developing device 103 has a so-called developing cartridge structure, and is preferably provided detachably with respect to the image forming unit U2. This is because the developer (structural material, support material) can be easily replenished and changed by exchanging the cartridge. Alternatively, the image carrier 100, the developing device 103, the cleaning device 105, and the like may be integrated into a cartridge (so-called process cartridge) so that the image carrier itself can be replaced. When the wear and life of the image carrier 100 are particularly problematic due to the type, hardness, and particle size of the structural material and support material, the process cartridge configuration is more practical and convenient.

(Transfer device)
The transfer device 104 is a transfer unit that transfers the material image on the image carrier 100 onto the surface of the first conveyance belt 11. The transfer device 104 is disposed on the opposite side of the image carrier 100 with the first conveyance belt 11 interposed therebetween, and electrostatically applies a voltage having a polarity opposite to that of the material image on the image carrier 100. The material image is transferred to the conveying belt 11 side. Transfer from the image carrier 100 to the first conveying belt 11 is also referred to as primary transfer. In the modeling apparatus of FIG. 4, a transfer method using corona discharge is used, but a transfer method other than a roller transfer method or an electrostatic transfer method can also be adopted.

(Cleaning device)
The cleaning device 105 is a unit that collects developer particles remaining on the image carrier 100 without being transferred, and cleans the surface of the image carrier 100. In FIG. 4, a blade type cleaning device 105 that scrapes off developer particles with a cleaning blade brought into contact with the image carrier 100 in the counter direction is employed. However, a brush type or electrostatic adsorption type cleaning device is used. It may be used.

(First conveyor belt)
The first conveyor belt 11 is a carrier on which a material image formed by each material image forming unit 10 is transferred. First, the material image of the structural material is transferred from the upstream material image forming unit 10 a in the conveyance direction of the first conveyance belt 11. Thereafter, in consideration of the arrangement with respect to the material image previously transferred to the first conveyance belt 11, the material image of the support material is transferred from the material image forming unit 10b on the downstream side, whereby the first conveyance belt 11 One material layer is formed on the surface.

  The first conveyor belt 11 is an endless belt made of a material such as resin or polyimide, and is stretched around a plurality of rollers 110 and 111 as shown in FIG. A tension roller may be provided in addition to the rollers 110 and 111 so that the tension of the first transport belt 11 can be adjusted. At least one of the rollers 110 and 111 is a driving roller, and the first conveying belt 11 is rotated counterclockwise in the drawing by the driving force of a motor (not shown) during image formation. The roller 110 is a roller that forms a secondary transfer portion with the secondary transfer roller 31 of the stacking unit U3.

(Belt cleaning device)
The belt cleaning device 12 is a means for cleaning the material adhering to the surface of the first transport belt 11. In the present embodiment, a blade type cleaning device is used in which the material is scraped off by a cleaning blade brought into contact with the first conveying belt 11 in the counter direction. However, a brush type or electrostatic adsorption type cleaning device is used. Also good.

(Image detection sensor)
The image detection sensor 13 is a detection unit that reads a material image carried on the surface of the first conveyance belt 11. The detection result of the image detection sensor 13 is material image alignment, timing control with the subsequent layered portion U3, material image abnormality detection (not desired image, no image, large variation in thickness, image displacement For example, large).

[Laminated part]
Next, the configuration of the stacked unit U3 will be described. The stacking unit U3 is a unit that produces a three-dimensional object by receiving the material layer formed by the layer forming unit U2 from the first holding and conveying belt 11 and sequentially stacking and fixing the material layer.

  As illustrated in FIG. 4, the stacking unit U <b> 3 includes a second conveyance belt 30, a secondary transfer roller 31, an image detection sensor 32, a counter member 33, a stage 34, and an elastic member 35. Hereinafter, the structure of each part of the lamination | stacking part U3 is demonstrated in detail.

(Second conveyor belt)
The second transport belt 30 receives the material layer from the first transport belt 11 and carries and transports the material layer to the stacking position. The lamination position is a position where the material layers are laminated (stacked on the lamination surface). In the configuration of FIG. 4, the second conveyance belt 30 is sandwiched between the facing member 33, the elastic member 35, and the stage 34. The part corresponds to the stacking position.

The second conveyor belt 30 has an endless belt made of a material such as resin or polyimide, or a medium resistance layer (volume resistivity 1 × 10 ⁶ to 10 ¹³ Ω · cm) provided on a metal sheet. An endless belt can be used. When the conveyor belt contains metal, it is preferable because temperature control during lamination can be performed in a relatively short time.

  The second conveyance belt 30 is stretched around the secondary transfer roller 31 and a plurality of rollers 301, 302, 303, 304. At least one of the rollers 31, 301, and 302 is a driving roller, and the second conveying belt 30 can be rotated clockwise in the drawing by a driving force of a motor (not shown).

(Secondary transfer roller)
The secondary transfer roller 31 is a transfer unit for transferring the material layer from the first transport belt 11 to the second transport belt 30. The secondary transfer roller 31 sandwiches the first transport belt 11 and the second transport belt 30 with the opposing roller 110 of the layer forming unit U2, thereby forming a secondary transfer nip between the belts. The material layer can be transferred to the second conveying belt 30 by applying a bias having a polarity opposite to that of the material image to the secondary transfer roller 31 by a power source (not shown).

(Image detection sensor)
The image detection sensor 32 is a detection unit that reads a material layer carried on the surface of the second conveyance belt 30. The detection result of the image detection sensor 32 is used for alignment of the material layer, conveyance timing control to the stacking position, and the like.

(Opposing member)
The facing member 33 is a pressing member for pressing the stage 34 or the modeled object against the material layer conveyed to the stacking position and applying pressure. The facing member 33 is disposed at a position facing the stage 34 with the second conveyor belt 30 in between, and the pressing surface facing the stage 34 is a flat surface. However, the pressing surface of the facing member 33 is not necessarily a flat surface. For example, a roller-shaped member having a rotation axis perpendicular to the conveyance direction of the second conveyance belt 30 can be employed. When the facing member 33 has a roller shape, the same problem as the facing member 33 having a flat pressing surface occurs unless the rotation axis and the laminated surface are parallel.

  Moreover, the opposing member 33 is provided with the temperature control means which controls the temperature of a material layer, and can heat a material layer more than softening temperature. As the temperature control means, for example, a heating means capable of temperature control such as a ceramic heater or a halogen heater can be used. In addition to the heating unit, a cooling unit that actively lowers the temperature of the material layer by heat dissipation or cooling using a chiller or the like may be provided.

(stage)
The stage 34 is a flat table on which material layers are stacked to produce a three-dimensional object. The stage 34 can be moved in the material layer stacking direction by an actuator (not shown). The material layer carried and conveyed to the lamination position is sandwiched between the elastic member 35 and the lamination surface together with the second conveyance belt, and heated and pressurized, so that the material layer is transferred from the second conveyance belt 30 to the stage 34. Transfer to The first material layer is directly transferred onto the stage 34, and the second and subsequent material layers are stacked on the three-dimensional object being manufactured on the stage 34. Regardless of whether it is on the stage 34 or the three-dimensional object being produced, the surface on which the material layers are laminated is referred to as the laminated surface.

(Elastic member)
In the present embodiment, the elastic member 35 is disposed on the pressure surface (the surface facing the stage lamination surface) side of the facing member 33. According to such a configuration, as described in FIG. 2, the elastic member 35 of the opposing member 33 is provided in a state where the three-dimensional object being modeled, the material layer, and the second transport belt are stacked. Press against the surface and pressurize. Then, even when the layered surface of the modeled object and the pressing surface of the opposing member 33 are not parallel, the entire surface of the material image region is pressurized because the entire surface of the stage 34 and the opposing member 33 is brought into contact by the contraction action of the elastic member 35. As a result, the heat necessary for fixing the laminate is sufficiently transmitted. As a result, it is possible to suppress the occurrence of stacking faults.

  As described above, when the facing member 33 has a roller shape, the elastic member may be disposed along the circumferential surface of the roller that becomes the pressing surface.

[Operation of modeling equipment]
Next, a modeling operation when producing a three-dimensional object using the modeling apparatus having the above configuration will be described. Here, a description will be given assuming that slice data of a three-dimensional model has already been acquired. FIG. 5 is a flowchart showing an operation sequence of the modeling apparatus of this embodiment.

  First, the control unit U1 causes the image carrier 100, the first conveyance belt 11, and the second conveyance belt 30 of each material image forming unit 10 to rotate synchronously at the same outer peripheral speed (process speed). Control the drive source such as motor.

  After the rotation speed is stabilized, a material image made of the first modeling material is formed by using a known electrophotographic process in the upstream material image forming unit 10a (S501). This material image is primarily transferred onto the first conveying belt 11 by the transfer device 104a.

  In response to a control signal from the control unit U1, the material image forming unit 10b performs the second modeling in the same manner as the material image forming unit 10a after a predetermined time from the start of image formation in the material image forming unit 10a. Formation of a material image made of material is started (S502). At this time, by adjusting the time difference of image formation start in the material image forming units 10a and 10b, the material images formed separately in the respective material image forming units are aligned and arranged on the first conveying belt 11. Then, one material layer is formed (S503). As the first modeling material, an example in which a structural material constituting a three-dimensional model is used and a support material is used as the second modeling material can be considered. In the case of a material layer that does not require the placement of the second modeling material, image formation in the material image forming unit 10b is not performed, and the material layer is formed only with the material image of the first modeling material. Thereafter, the material layer is conveyed by the first conveying belt 11 to the stacking unit U3.

  While the material layer forming operation is performed as described above, the second conveyor belt 30 of the stacked unit U3 rotates synchronously at the same outer peripheral speed (process speed) while being in contact with the first conveyor belt 11. ing. Then, the control unit U1 applies a predetermined transfer bias to the secondary transfer roller 31 in accordance with the timing at which the front end of the material layer on the first conveying belt 11 reaches the secondary transfer nip, and the material layer is moved to the second transfer roller 31. Is transferred to the conveying belt 30 (S506).

  The second conveyor belt 30 continues to rotate at the same process speed and conveys the material layer in the direction of the arrow in FIG. When the image detection sensor 32 detects the position of the material layer on the belt, the control unit U1 conveys the material layer to a predetermined stacking position based on the detection result (S508). At the timing when the material layer reaches the stacking position, the control unit U1 stops the second transport belt 30 and positions the material layer at the stacking position (S509). Thereafter, the control unit U1 raises the stage 34 so as to be close to the belt surface, and the stage surface or the upper surface of the modeled object on the stage surface is brought into contact with the material layer on the second conveyance belt 30, and between the opposing member 33. The shaped object and the material layer are pressurized by being sandwiched (S510). Maintaining this state, the control unit U1 controls the temperature of the temperature raising means provided in the facing member 33 according to a predetermined temperature control sequence. Specifically, first, the first mode in which the facing member 33 is heated to the first target temperature is performed for a predetermined time, and the particle material of the material layer is thermally melted (S511). That is, in the first mode, the material layer is heated by the facing member 33. Thereby, the material layer is softened, and the sheet-like material image and the stage surface or the three-dimensional modeled object upper surface are in close contact with each other. At this time, even when the laminated surface of the three-dimensional structure and the pressing surface of the opposing member 33 are not parallel, the pressure member and the temperature unevenness between the three-dimensional object and the material layer are reduced by the contracting action of the elastic member 35, and the pressure shortage and heat It is possible to suppress the stacking failure caused by the shortage. After that, the second mode for controlling the facing member 33 to a second target temperature lower than the first target temperature is performed for a predetermined time to solidify the softened material layer (S512).

  In the first mode and the second mode, if the temperature control range is too wide, it takes time to stabilize the temperature control, and the stacking process time takes more than necessary. Therefore, in the control range of the first target temperature, the highest temperature among the melting points or glass transition points of the materials constituting the material layer is set as the lower limit temperature, and the upper limit temperature is preferably set to about + 50 ° C. of the lower limit temperature. Similarly, in the control range of the second target temperature, the lowest temperature of the crystallization temperature of each material constituting the material layer or the glass transition point of the amorphous material is the upper limit temperature, and the lower limit temperature is the upper limit temperature. It is good to set at about -50 ° C. After the end of the second mode, the control unit U1 lowers the stage 34 and moves it away from the facing member 33 (S513).

  After the entire material layer has been transferred from the surface of the second conveyor belt 30 to the lamination surface, it is determined whether or not the necessary number of material layers have been laminated (S514), and the necessary number has been reached. If the required number has not been reached, execution of the material image forming process for the next layer is started (S501 to S501).

  A desired three-dimensional object is formed on the stage 34 by repeating the above steps as many times as necessary. After the three-dimensional object is completed, the final three-dimensional object (article) corresponding to the three-dimensional model can be obtained by removing the three-dimensional object from the stage 34 and removing the support material. Note that after the support material is removed, a final three-dimensional object (article) may be manufactured by performing predetermined processing (for example, cleaning, assembly, etc.) on the three-dimensional object.

  As described above, if modeling is performed using the modeling apparatus according to the present embodiment, the elastic member 35 contracts even if the pressing surface of the facing member 33 and the laminated surface on the stage 34 are not parallel. Stacking failure can be suppressed. As a result, a three-dimensional object with high modeling accuracy can be produced.

Second Embodiment
FIG. 6 shows an outline of the configuration at the stacking position of the three-dimensional modeling apparatus according to this embodiment. The present embodiment is the same as the first embodiment except that the elastic member 35 is arranged on the surface of the laminated surface of the stage 34 except that the elastic member 35 is different from the first embodiment.

  Also in this embodiment, when the solid object and the material layer are pressed against the second conveying belt 30 and the opposing member 33 and pressed and heated, the elastic member 35 contracts between the material layer and the laminated surface. The resulting pressure and temperature variations can be reduced. As a result, even when the pressing surface of the facing member 33 and the three-dimensional object stacking surface are not parallel, it is possible to suppress stacking faults.

  Further, in the present embodiment, since the elastic member 35 does not exist between the facing member 33 provided with the heating means and the material layer, the temperature control of the material layer can be performed in a shorter time than the first embodiment. This is preferable because it is possible.

<Third Embodiment>
In order to make it easy to remove the three-dimensional object after the modeling from the stage 34, there is a method of modeling after providing a modeling plate that is easy to remove on the laminated surface side of the stage.

  Various materials can be used for the modeling plate. However, when the modeling plate itself has an elastic modulus that functions as an elastic member, it is included in the second embodiment. Therefore, in the present embodiment, a case where a plate-like member made of a material having a high elastic modulus such as a metal is used for the modeling plate will be described.

  When using a modeling plate with a high elastic modulus, a mode in which the elastic member is arranged on the surface of the modeling plate facing the facing member and a mode in which the elastic member is arranged between the modeling plate and the stage are conceivable.

  First, the form in which the elastic member is arranged on the surface of the modeling plate facing the facing member can be realized by installing the modeling plate provided with the elastic member on the stage, and has the same configuration as FIG. Since an effect can be obtained, detailed description is omitted.

  Next, a mode in which an elastic member is provided between the modeling plate and the stage will be described. The configuration of the modeling apparatus at the stacking position is shown in FIG. Although it differs from 1st Embodiment by the point by which the elastic member 35 is arrange | positioned between the modeling plate 40 which can be removed, and a stage, others are the same as that of 1st Embodiment.

  When the pressing surface of the opposing member 33 and the laminated surface of the three-dimensional object are not parallel, when the opposing member 33, the material layer, the second conveying belt 30, and the modeling plate 40 start to contact each other, the elastic portion receives the force. 35 begins to deform. That is, the entire material layer can be brought into contact with the laminated surface by the contracting action of the elastic member 35. As a result, even if the pressing surface of the facing member 33 and the three-dimensional object stacking surface are not parallel, it is possible to perform modeling while reducing stacking faults. A configuration in which a plurality of springs are disposed between the modeling plate 40 and the stage 34 can be employed as the elastic member 35.

  The modeling plate 40 is installed on the stage in a form that does not limit the deformation of the elastic member 35. For example, the elastic member 35 and the surface of the stage 34 facing the opposing member 33 may be fixed with an adhesive, and the modeling plate 40 may be fixed to the elastic member 35 with a material having an appropriate adhesive force. In addition, there is a first plate having a laminated surface on which modeling is performed and a second plate for fixing to the stage, and an elastic member 35 is sandwiched between the first plate and the second plate. A modeling plate 40 may be used. The second plate has a structure that can be detachably fixed to the stage with a screw or a fitting structure, and the elastic member 35 has a configuration in which the contact surfaces of the first plate and the second plate are fixed with an adhesive. preferable.

  Next, the form in which the modeling plate does not have an elastic member will be described. If the modeling plate does not include an elastic member, a stacking failure may occur as it is, and therefore, it may be combined with the first embodiment or the second embodiment. When the modeling plate having no elastic member is combined with the second embodiment, a configuration equivalent to that in FIG. 7 can be realized.

  As described above, when a modeling plate is used, it is preferable to arrange an elastic member on the surface of the modeling plate facing the opposing member, or to install a modeling plate having an elastic member on the stage. With such a configuration, it is possible to suppress the occurrence of stacking faults and to easily remove the three-dimensional object after modeling from the stage 34, thereby shortening the modeling time per one three-dimensional object.

U2 Image forming unit 10a, 10b Material image forming unit 11 First conveying belt 20 Conveying body (conveying belt)
U3 Laminating section 30 Second conveyor belt 33 Opposing member 34 Stage 35 Elastic member 36 Material layer 37 Three-dimensional object

Claims (13)

A modeling apparatus for producing a three-dimensional object by stacking material layers formed based on slice data of a three-dimensional model,
A layer forming part for forming the material layer;
A laminating part for laminating the material layer on the laminating surface;
With
The stacking section is a stage on which the material layer is stacked;
An opposing member that pressurizes the material layer with the stage interposed therebetween;
An elastic member;
With
The elastic member is provided on the stage or the opposing member;
The modeling apparatus, wherein the stage or the opposing member pressurizes the material layer via the elastic member.   The modeling apparatus according to claim 1, wherein the elastic member has a sheet shape.   The modeling apparatus according to claim 1 or 2, wherein the elastic member is a member of 60 or less in a type D durometer conforming to JISK6253.   The modeling apparatus according to claim 3, wherein the elastic member is a member of 90 or less in a type A durometer conforming to JISK6253.   The elastic member is made of a material selected from chloroprene rubber, nitrile rubber, natural rubber, ethylene / propylene rubber, fluorine rubber, urethane rubber, silicone rubber, and these rubber sponges. The modeling apparatus according to claim 3.   The modeling apparatus according to any one of claims 1 to 5, wherein a thickness of the elastic member in a direction perpendicular to the laminated surface is 0.1 mm or more and 2 mm or less.   The modeling apparatus according to claim 1, wherein the elastic member is provided on a surface of the facing member that faces the stage.   The modeling apparatus according to claim 1, wherein the elastic member is provided on a surface of the stage that faces the facing member.   The modeling apparatus according to any one of claims 1 to 8, wherein the stage has a structure for installing a modeling plate on a surface facing the facing member.   The modeling apparatus according to claim 9, wherein the elastic member is provided between the modeling plate and the stage.   The modeling apparatus according to claim 8, wherein the modeling plate includes the elastic member on a surface facing the facing member.   The modeling apparatus according to claim 1, wherein the facing member includes a heating unit capable of controlling temperature.   The modeling according to any one of claims 1 to 12, further comprising a transport body that transports the material layer from the layer forming section to the stacking section, wherein the transport body includes a metal. apparatus.

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