JP2019018491A - Three-dimensional molding apparatus and three-dimensional molding method - Google Patents

Abstract

To provide a technique capable of realizing downsizing of a three-dimensional molding apparatus and improvement of molding accuracy of a three-dimensional molded object.SOLUTION: A three-dimensional molding apparatus includes a driving motor, a flat screw rotated by the driving motor and having a scroll groove forming surface on which a scroll groove is formed, a screw facing part facing the scroll groove forming surface and having a communication hole at a center and having a heater, a plasticizing part for plasticizing a material supplied between the flat screw and the screw facing part by rotation of the flat screw and heating by the heater and converting it into a molten material, and a nozzle for injecting the molten material supplied from the communication hole.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional modeling apparatus and a three-dimensional modeling method.

  Patent Document 1 describes an extrusion deposition additive manufacturing apparatus using a molten resin. This apparatus manufactures a three-dimensional object by melting a wire-shaped thermoplastic material with a preheater and extruding the molten material from an extrusion nozzle using rotation of a long screw. In addition, since the three-dimensional object manufactured by extrusion has many gaps and a low filling degree, the gap between the three-dimensional objects is reduced by supplying a solvent to the cured material and dissolving the cured material.

JP 2006-192710 A

  In the prior art described above, since the melted material is extruded using a long screw-like rotation, there is a problem in that the overall height of the apparatus becomes considerably large and miniaturization cannot be achieved. Further, since the material extruded from the nozzle has many gaps, the modeling accuracy is low, and there is a problem that it is necessary to use a solvent in order to increase the modeling accuracy. As described above, regarding the three-dimensional modeling technology, it has been desired to reduce the size of the apparatus and improve the modeling accuracy of the three-dimensional model.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to the first aspect of the present invention, a three-dimensional modeling apparatus for manufacturing a three-dimensional modeled object using a thermoplastic material is provided. This three-dimensional modeling apparatus has a drive motor; a scroll groove forming surface in which scroll grooves are formed, a flat screw rotated by the drive motor, and the scroll groove forming surface, and a communication hole is formed at the center. A screw facing portion having a heater inside, and plasticizing and melting the material supplied between the scroll groove forming surface and the screw facing portion by rotation of the flat screw and heating by the heater A plasticizing part to be converted into a material; and a nozzle for injecting the molten material supplied from the communication hole. According to the three-dimensional modeling apparatus of this aspect, since the material is plasticized by the plasticizing part having the flat screw, the height of the apparatus can be reduced, and the entire apparatus can be reduced in size.

(2) In the three-dimensional modeling apparatus of the above aspect, the depth of the scroll groove may become deeper toward the outer peripheral side of the flat screw. In such a form, even if gas is generated during plasticization of the material, the gas can be efficiently discharged to the outside.

(3) In the three-dimensional modeling apparatus of the above aspect, a plurality of material inflow ports for receiving the material between the flat screw and the screw facing portion may be formed on a side surface of the flat screw. If it is such a form, material can be efficiently received in a plasticization part.

(4) In the three-dimensional modeling apparatus of the above aspect, the flat screw may have a stay prevention portion that protrudes toward the communication hole. If it is such a form, it will be suppressed that a molten material retains in the edge part inside a scroll groove, and a molten material can be smoothly sent out to a communicating hole.

(5) In the three-dimensional modeling apparatus according to the above aspect, the scroll groove is defined by an inner wall located on the radially inner side, an outer wall located on the radially outer side, and a bottom wall. , And a guide groove for guiding the material toward the outer wall. In such a form, since the material is guided to the outer wall, the material can be efficiently kneaded by the outer wall.

(6) In the three-dimensional modeling apparatus of the above aspect, a recess may be formed on the bottom wall of the scroll groove. If it is such a form, when gas arises with plasticization of material, the gas can be efficiently discharged | emitted outside through a recessed part.

(7) According to the second aspect of the present invention, there is provided a three-dimensional modeling method for manufacturing a three-dimensional modeled object using a thermoplastic material. The three-dimensional modeling method includes a step of plasticizing the material by rotation of a flat screw and heating by a heater to convert it into a molten material; and a step of injecting the molten material using a nozzle to form the three-dimensional modeled object. And comprising; According to the three-dimensional modeling method of this aspect, since the material is plasticized by the plasticizing part having a flat screw, it is possible to manufacture a three-dimensional modeled object using a small apparatus.

  The present invention can be implemented in various forms other than the above. For example, it can be realized in the form of a computer program for realizing the functions of the 3D modeling apparatus or the 3D modeling method, a non-temporary tangible recording medium on which the computer program is recorded, and the like.

It is a conceptual diagram of the three-dimensional modeling apparatus in 1st Embodiment. It is a perspective view of a flat screw. It is a top view of a screw facing part. It is explanatory drawing which shows the positional relationship of a three-dimensional structure and a nozzle front-end | tip. It is explanatory drawing which shows an example of a nozzle hole. It is a figure which shows the relationship between the shape of a nozzle hole, the nozzle hole diameter, and surface roughness. It is explanatory drawing which shows the other example of a nozzle hole. It is explanatory drawing which shows the other example of a nozzle hole. It is explanatory drawing which shows the other example of a nozzle hole. It is a perspective view of the flat screw in 2nd Embodiment. It is a perspective view of the flat screw in a 3rd embodiment. It is a figure which shows the other form of the flat screw in 3rd Embodiment. It is a perspective view of the flat screw in a 4th embodiment. It is a figure which shows the other form of the flat screw in 4th Embodiment. It is a perspective view of the flat screw in a 5th embodiment. It is a figure which shows the other form of the flat screw in 5th Embodiment. It is a conceptual diagram of the three-dimensional modeling apparatus in 6th Embodiment.

A. First embodiment:
FIG. 1 is a conceptual diagram of a three-dimensional modeling apparatus 1 in the first embodiment. The three-dimensional modeling apparatus 1 includes an injection unit 100, a moving mechanism 200, and a control unit 300. FIG. 1 shows three directions X, Y, and Z perpendicular to each other. The X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. In other drawings, these directions are illustrated as necessary.

  The injection unit 100 includes a drive motor 30, a plasticizing unit 90, and a nozzle 60. The plasticizing part 90 has a flat screw 40 and a screw facing part 50. The flat screw 40 is housed in the screw case 10 and is rotated by the drive motor 30. The screw facing portion 50 faces the scroll groove forming surface 48, and a communication hole 56 is formed at the center. The screw facing portion 50 has a heater 58 inside. The plasticizing part 90 plasticizes the material supplied between the flat screw 40 and the screw facing part 50 by rotation of the flat screw 40 and heating by the heater 58, and converts it into a molten material. The molten material is supplied to the nozzle 60 from the communication hole 56. The nozzle 60 injects the molten material supplied from the communication hole 56. The tip of the nozzle 60 has a nozzle hole diameter Dn. “Plasticization” means that a material is heated and melted. The injection unit 100 can also be regarded as a three-dimensional modeling apparatus in a narrow sense.

  The plasticizer 90 is supplied with material from the hopper 20 via the communication path 22. The hopper 20 is charged with a thermoplastic material. Examples of materials include polypropylene resin (PP), polyethylene resin (PE), polyacetal resin (POM), polyvinyl chloride resin (PVC), polyamide resin (PA), acrylonitrile-butadiene-styrene resin (ABS), and polylactic acid. Resin (PLA), polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), polycarbonate (PC), etc. can be used. Further, as the shape of the material, a solid material such as pellets or powder can be used. Further, the thermoplastic material may be a composition containing a thermoplastic material and other components.

  The moving mechanism 200 is a three-axis positioner capable of moving the modeling table 220 placed on the table 210 in the three axial directions of the X direction, the Y direction, and the Z direction. The moving mechanism 200 has a function of changing the relative positional relationship between the nozzle 60 and the modeling table 220. By changing the relative positional relationship between the nozzle 60 and the modeling table 220 using the moving mechanism 200, a three-dimensional modeled object having an arbitrary shape can be manufactured. In this embodiment, the moving mechanism 200 moves the modeling table 220 three-dimensionally, but the moving mechanism 200 employs a mechanism that moves the nozzle 60 (that is, the injection unit 100) three-dimensionally. Also good. Alternatively, a moving mechanism that moves one of the nozzle 60 (that is, the injection unit 100) and the modeling table 220 in one or two axial directions and moves the other in the remaining axial directions may be employed.

  The controller 300 controls the drive motor 30 and the heater 58 of the injection unit 100 and the moving mechanism 200. The control unit 300 can be realized by a computer including a processor such as a CPU, a main memory, and a nonvolatile memory, for example. A computer program for controlling the 3D modeling apparatus 1 is stored in the non-volatile memory in the control unit 300. The control unit 300 executes the computer program, thereby plasticizing the material by rotation of the flat screw 40 and heating by the heater 58 to convert the material into a molten material, and injecting the molten material using the nozzle 60 to obtain the tertiary. And realizing a three-dimensional modeling method including a step of forming an original model.

  FIG. 2 is a perspective view of the flat screw 40. The flat screw 40 is a substantially cylindrical screw whose axial height is smaller than its diameter. The flat screw 40 has a plurality of scroll grooves 42 on the surface facing the screw facing portion 50 (FIG. 1). The surface on which the scroll grooves 42 are formed is referred to as a “scroll groove forming surface 48”. The scroll groove 42 is formed in a spiral shape or a spiral shape from the outer periphery of the flat screw 40 toward the central portion 46 of the scroll groove forming surface 48. The depth of the scroll groove 42 becomes deeper toward the outer peripheral side of the flat screw 40. However, the depth of a part of the scroll groove 42 (for example, a part near the central part 46) may be constant. A plurality of material inlets 44 for receiving material are formed between the flat screw 40 and the screw facing portion 50 on the side surface 43 of the flat screw 40. The material inlet 44 is continuous with the scroll groove 42. Material is supplied from the hopper 20 to the material inlet 44 via the communication path 22.

  The scroll groove 42 is defined by an inner wall 421 positioned radially inward, an outer wall 422 positioned radially outward, and a bottom wall 423. For example, the inner wall 421 and the outer wall 422 have respective shapes based on an involute curve based on a circle concentric with the rotation center of the flat screw 40. The material supplied into the scroll groove 42 is guided from the outer wall 422 side toward the inner wall 421 side as the flat screw 40 rotates. Further, when the flat screw 40 rotates, the material is kneaded between the scroll groove 42 and the screw facing portion 50 and plasticized by being heated by the heater 58 to be converted into a molten material.

  FIG. 3 is a plan view of the screw facing portion 50. The screw facing portion 50 has a screw facing surface 52 that faces the scroll groove forming surface 48 of the flat screw 40. A plurality of guide grooves 54 formed in a spiral shape or a spiral shape are formed on the screw facing surface 52. A communication hole 56 for supplying the molten material to the nozzle 60 is formed at the center of the screw facing surface 52. The plurality of guide grooves 54 have a function of guiding the molten material to the communication hole 56. As shown in FIG. 1, a heater 58 for heating the material is embedded in the screw facing portion 50.

  The molten material is injected from the nozzle 60 in a state in which it is heated above its glass transition point and completely melted. For example, the ABS resin has a glass transition point of about 120 ° C. and is about 200 ° C. when injected from the nozzle 60. Thus, a heater may be provided around the nozzle 60 in order to inject the molten material at a high temperature.

  FIG. 4 is an explanatory diagram showing a positional relationship between the three-dimensional structure and the nozzle tip. On the modeling table 220, a three-dimensional model OB being manufactured is placed. A gap G is held between the tip of the nozzle 60 and the upper surface OBt of the three-dimensional structure OB. Here, the “upper surface OBt of the three-dimensional structure OB” means a planned site where the molten material injected from the nozzle 60 is landed in the vicinity of the position directly below the nozzle 60. The size of the gap G is preferably 1.1 to 1.5 times, and preferably 1.1 to 1.3 times the hole diameter Dn (FIG. 1) of the nozzle hole of the nozzle 60, for example. It is particularly preferred. In this way, the molten material injected from the tip of the nozzle 60 is deposited on the upper surface OBt of the three-dimensional structure OB in a free state so as not to be pressed against the upper surface OBt of the three-dimensional structure OB being manufactured. As a result, deposition can be performed while maintaining the cross-sectional shape of the molten material injected from the nozzle 60, so that the surface roughness of the three-dimensional structure OB can be reduced. Further, in the case where a heater is provided around the nozzle 60 in order to inject the molten material in a high temperature state, when deposition is performed with the molten material pressed against the upper surface OBt of the three-dimensional structure OB by the nozzle 60, Since the deposited material is continuously heated by the nozzle 60, the material is overheated, which may cause problems such as discoloration and deterioration. On the other hand, if the gap G is formed between the tip of the nozzle 60 and the upper surface OBt of the three-dimensional structure OB, there is an advantage that such overheating of the material can be prevented. Further, when the gap G is larger than 1.5 times the nozzle hole diameter Dn (FIG. 1), the accuracy with respect to the planned site where the molten material lands and the adhesion to the upper surface OBt of the three-dimensional structure OB being manufactured are increased. It may cause problems such as lowering.

  Further, the injection unit 100 of the present embodiment plasticizes the material using the flat screw 40 to change it into a molten state, and injects the molten material from the nozzle 60 to produce a three-dimensional structure, so that various materials can be used. And a three-dimensional structure can be manufactured using the material of shape. This is a great advantage over a normal FDM (thermal melting lamination) 3D printer, which requires a filament of material.

  FIG. 5 is an explanatory diagram illustrating an example of a nozzle hole. The nozzle hole 62a of the nozzle 60a has a substantially quadrangular cross section. Strictly speaking, the cross section of the nozzle hole 62a is square, and its four corners are rounded with R0.1. If such a nozzle 60a is used, the cross section of the molten material injected from the nozzle hole 62a has a shape closer to a square than a circle. As a result, the gap between the deposited linear molten materials can be reduced. The shape of the cross section of the nozzle hole 62a may be a shape close to a polygon (for example, a hexagon) other than a quadrangle.

  In the description of FIG. 5, the lowercase letter “a” attached to the end of the reference numerals of the nozzle 60 a and the nozzle hole 62 a is an additional reference numeral added to indicate that it is a specific shape example. In the case where such an additional code is unnecessary, “a” is omitted for the description. The same applies to the symbols “b” and “c” in other examples described later.

  FIG. 6 is a diagram showing the shape of the nozzle hole 62 and the relationship between the nozzle hole diameter and the surface roughness. Here, as the nozzle 60, a nozzle hole 62 having a circular cross-sectional shape (nozzle number # 1, # 2) and a rectangular one (nozzle number # 3) were used. The nozzle with nozzle number # 3 is the nozzle 60a shown in FIG. The hole diameter of the nozzle hole 62 is φ1 mm and φ0.3 mm for the nozzle numbers # 1 and # 2, and 1 mm for each side of the nozzle number # 3. Three types of three-dimensional structures were manufactured using each of these three types of nozzles 60, and the surface roughness Rz was measured. The surface roughness Rz is a “maximum height Rz” defined in JIS B 0601: 2013.

  In this specification, “the diameter of the nozzle hole 62” means the diameter of the nozzle hole 62 having a circular cross section. Moreover, when the cross section of the nozzle hole 62 is square, it means the length of one side. Furthermore, when the cross section of the nozzle hole 62 is a square, it means the length of the long side.

  When the nozzles 60 having nozzle numbers # 1 and # 2 in which the cross section of the nozzle hole 62 is circular were used, the surface roughness Rz was about half of the diameter of the nozzle hole 62. This is because a linear molten material having a substantially circular cross section is injected from the nozzle hole 62 having a circular cross section, and when the linear material is deposited, half of its diameter is roughened on the surface of the three-dimensional structure. This is presumed to be due to the height (maximum height Rz). On the other hand, when the nozzle 60 of nozzle number # 3 whose cross section of the nozzle hole 62 is a quadrangle (exactly a square) is used, the surface roughness Rz is smaller than half of the diameter of the nozzle hole 62 (one side of 1 mm). It was much smaller. The reason for this is that a linear molten material having a substantially rectangular cross section is injected from the nozzle hole 62 having a rectangular cross section, and when the linear material is deposited, small gaps between the substantially rectangular corners are three-dimensionally formed. This is presumed to be because the surface roughness (maximum height Rz) of the modeled object is reached. Considering this result, the cross section of the nozzle hole 62 of the nozzle 60 is preferably closer to a quadrangle than a circle.

  FIG. 7 is an explanatory view showing another example of the nozzle hole 62. The nozzle hole 62b of the nozzle 60b has a cross-sectional shape distorted like a pincushion. That is, the cross section of the nozzle hole 62b has a shape in which four sides thereof are curved in a concave shape from the corner portion toward the center. The shape of the cross section of the nozzle hole 62d is also a kind of a substantially square shape. If such a nozzle 60b is used, the cross-section of the molten material injected from the nozzle hole 62b can be made a shape that is closer to a square or square than the nozzle 60a of FIG. As a result, there is an advantage that the gap between the deposited linear molten materials can be further reduced.

  As can be understood from the examples of FIGS. 5 and 7 described above, the cross-sectional shape of the nozzle hole 62 is such that the cross-section of the molten material injected from the nozzle hole 62 is closer to a polygon (particularly a quadrangle) than a circle. It is preferable to be formed as follows. According to this configuration, since the cross section of the molten material injected from the nozzle hole 62 has a shape closer to a polygon than a circle, the gap between the deposited linear molten materials can be reduced. As a result, the surface roughness of the three-dimensional structure is reduced, so that the modeling accuracy can be improved.

  FIG. 8 is an explanatory view showing still another example of the nozzle hole 62. The nozzle 60c has four nozzle holes 62c arranged in a matrix. The cross section of each nozzle hole 62c has a substantially square shape. If the plurality of nozzle holes 62c are provided as in this example, the shape of the molten material injected from the nozzle 60c can be adjusted by the arrangement of the plurality of nozzle holes 62c. Accordingly, it is possible to reduce the surface roughness and improve the design of the three-dimensional structure. As the arrangement of the plurality of nozzle holes 62c, it is possible to adopt an arrangement other than a matrix shape. However, if the plurality of nozzle holes 62c are arranged in a matrix, the entire cross-sectional shape of the molten material injected from the nozzle 60c can be made to be a shape close to a quadrangle, so that the surface roughness can be further reduced. is there.

  FIG. 9 is an explanatory view showing still another example of the nozzle hole 62. In the nozzle 60d, five nozzle holes 62d are arranged at the positions of the “5” eyes of the dice. By adopting such an arrangement of the nozzle holes 62d, the shape of the molten material injected from the nozzle 60d can be intentionally made a unique shape with irregularities. Therefore, it is possible to improve the designability on the surface of the three-dimensional structure.

  In addition, the cross-sectional shape and arrangement | sequence of the nozzle hole 62 shown to FIG. 5, FIG. 7-9 are examples, and it is possible to employ | adopt various cross-sectional shapes and arrangement | sequences other than these.

  As described above, according to the three-dimensional modeling apparatus 1 of the present embodiment, since the material is plasticized by the plasticizing part 90 having the flat screw 40, the height of the apparatus can be reduced, and the entire apparatus can be reduced. It is possible to reduce the size. In addition, by devising the shape, number, and arrangement of the nozzle holes 62 of the nozzle 60, it is possible to improve the modeling accuracy and design of the three-dimensional structure.

  Further, in the three-dimensional modeling apparatus 1 of the present embodiment, since the depth of the scroll groove 42 is set to become deeper toward the outer peripheral side of the flat screw 40, gas is generated during plasticization of the material. However, the gas can be efficiently discharged to the outside. As a result, gas can be prevented from being mixed into the molten material, and the modeling accuracy of the three-dimensional structure can be improved. In addition, since the depth of the scroll groove 42 is set to be deeper toward the outer peripheral side of the flat screw 40, the material can be smoothly pumped toward the center of the flat screw 40.

  Moreover, in this embodiment, since the several material inflow port 44 is provided in the side surface 43 of the flat screw 40, a material can be received in the plasticization part 90 efficiently.

B. Second embodiment:
FIG. 10 is a perspective view of a flat screw 40A in the second embodiment. The flat screw 40 </ b> A according to the second embodiment includes a stay prevention portion 49 that protrudes toward the communication hole 56 provided in the screw facing portion 50. The stay prevention part 49 has a substantially conical shape and is provided at the center of rotation of the scroll groove forming surface 48 of the flat screw 40A. The distal end of the stay prevention part 49 is disposed inside the communication hole 56 rather than the opening end of the communication hole 56 of the screw facing part 50.

  According to the flat screw 40 </ b> A having such a configuration, the molten material is restrained from staying at the inner end of the scroll groove 42, so that the molten material can be smoothly delivered to the communication hole 56 of the screw facing portion 50. Can do. As a result, it is possible to prevent the material from being discolored or deteriorated due to the molten material being overheated near the central portion 46 of the flat screw 40.

C. Third embodiment:
FIG. 11 is a perspective view of a flat screw 40B in the third embodiment. The flat screw 40B according to the third embodiment includes two scroll grooves 42. Each scroll groove 42 includes a guide groove 424 that guides the material toward the outer wall 422. The guide groove 424 is provided in a portion of the scroll groove 42 where the material inlet 44 is provided. An angle formed between the bottom wall 423 of the guide groove 424 and the scroll groove forming surface 48 is relatively larger than the other part of the scroll groove 42 (for example, about 60 degrees). That is, the bottom wall 423 of the scroll groove 42 is further inclined at the portion where the invitation groove portion 424 is present than at the other portions.

  The guide groove portion 424 extends so as to draw an arc from the inner wall 421 to the outer wall 422 in the outer peripheral portion of the scroll groove 42. And as for the invitation groove part 424, the width | variety along the radial direction converges narrowly as it goes to the outer side wall 422 side from the inner side wall 421 side. At the end that narrows and converges, the guide groove 424 merges with the other part of the scroll groove 42, and the depth thereof is equal to the part of the other scroll groove 42. The bottom surface of the guide groove 424 constitutes a part of a conical surface with the rotation center of the flat screw 40 as an axis.

  According to the flat screw 40 </ b> B having such a shape, the material supplied to the material inlet 44 of the flat screw 40 </ b> B hits the guide groove 424 and is guided to the outer wall 422 side. Therefore, the material can be kneaded efficiently by the outer wall 422. The invitation groove 424 may be provided only in a part of the plurality of scroll grooves 42.

  FIG. 12 is a diagram showing another form of the flat screw in the third embodiment. The flat screw 40C shown in FIG. 12 has a configuration in which the stay prevention portion 49 shown in FIG. 10 (second embodiment) is provided with respect to the flat screw 40B of the third embodiment. According to the flat screw 40 </ b> C having such a configuration, the material can be efficiently kneaded by the outer wall 422 by the invitation groove portion 424, and the molten material can be supplied to the communication hole 56 of the screw facing portion 50 by the stay prevention portion 49. It can be sent out smoothly. In addition, the invitation groove part 424 in this embodiment is applicable not only to this embodiment but 1st Embodiment, 2nd Embodiment, and all the 4th-6th Embodiment mentioned later.

D. Fourth embodiment:
FIG. 13 is a perspective view of a flat screw 40D in the fourth embodiment. The flat screw 40 in each embodiment described above includes a plurality of scroll grooves 42, whereas the flat screw 40 </ b> D in the fourth embodiment includes only one scroll groove 42. Therefore, only one material inlet 44 is provided. Even with such a configuration, the height of the three-dimensional modeling apparatus 1 can be reduced as in the first embodiment, and the entire apparatus can be downsized. The scroll grooves 42 are not limited to 1 to 3 and may be formed with 4 or more.

  FIG. 14 is a diagram showing another form of the flat screw in the fourth embodiment. The flat screw 40E shown in FIG. 14 has a configuration in which the stay prevention portion 49 shown in FIG. 10 (second embodiment) is provided with respect to the flat screw 40D of the fourth embodiment. As described above, the stay prevention unit 49 can be applied to various types of flat screws regardless of the number of the scroll grooves 42.

E. Fifth embodiment:
FIG. 15 is a perspective view of a flat screw 40F in the fifth embodiment. In the flat screw 40F in the present embodiment, a recess 425 is formed in the bottom wall 423 of each scroll groove 42. The concave portion 425 is provided at the center in the width direction of the scroll groove 42 along the extending direction of the scroll groove 42 from the outermost periphery of the flat screw 40F toward the inner end of the scroll groove 42. .

  In this embodiment, since the recessed part 425 is provided in the scroll groove 42, even if gas is generated from the material during plasticization of the material, the gas is efficiently discharged along the recessed part 425 to the outside. Can do. The width of the recess 425 is preferably smaller than the diameter of the material put into the hopper 20. If the width | variety of the recessed part 425 is smaller than the diameter of material, it can suppress that the recessed part 425 will be obstruct | occluded with material. Further, the recess 425 may be formed in a part of the scroll grooves 42 among the plurality of scroll grooves 42.

  FIG. 16 is a diagram illustrating another form of the flat screw according to the fifth embodiment. The flat screw 40G shown in FIG. 16 has a configuration in which the stay prevention part 49 shown in FIG. 10 (second embodiment) is provided with respect to the flat screw 40F of the fifth embodiment. According to the flat screw 40G having such a configuration, gas can be prevented from being mixed into the molten material, and the molten material can be smoothly delivered to the communication hole 56 of the screw facing portion 50 by the stay prevention portion 49. .

  In addition, when providing the invitation groove part 424 shown in FIG. 12 (3rd Embodiment) with respect to the flat screws 40F and 40G of 5th Embodiment, it is not necessary to provide the recessed part 425 in the invitation groove part 424. FIG. This is because the guiding groove portion 424 has a large inclination and gas is easily released. However, of course, the recess 425 may be provided in the invitation groove 424.

F. Sixth embodiment:
FIG. 17 is a conceptual diagram of a three-dimensional modeling apparatus 1A in the sixth embodiment. This three-dimensional modeling apparatus 1A is different from the embodiment shown in FIG. 1 in that it has two injection units 100a and 100b, and other configurations are the same as those in FIG. In addition, since the structure of each injection unit 100a, 100b is the same as the injection unit 100 shown in FIG. 1, description is abbreviate | omitted.

Since the three-dimensional modeling apparatus 1A includes two injection units 100a and 100b, it is possible to manufacture a three-dimensional modeled object using two different types of materials. As a combination of two types of materials, for example, any of the following can be adopted.
(1) Material having different colors If a material having different colors is used, a three-dimensional structure having two different colors can be manufactured.
(2) Material for support material and material for modeling The support material is a member for holding the shape of the three-dimensional structure, and is a member that is removed after the completion of modeling. First, if a support material is injected from one of the two injection units 100a and 100b to produce a support material, and a three-dimensional structure is manufactured using the support material, a more complicated and diverse three-dimensional structure can be obtained. Can be manufactured.
(3) Material of different materials For example, if materials of two different materials are used, a three-dimensional structure can be manufactured with a material of an appropriate material according to the use of the three-dimensional structure.

  The number of injection units 100 is not limited to two, and three or more injection units 100 may be provided.

  The present invention is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments corresponding to the technical features in each embodiment described in the summary section of the invention are intended to solve part or all of the above-described problems, or one of the above-described effects. In order to achieve part or all, replacement or combination can be appropriately performed. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  DESCRIPTION OF SYMBOLS 1,1A ... Three-dimensional modeling apparatus, 10 ... Screw case, 20 ... Hopper, 22 ... Communication path, 30 ... Drive motor, 40, 40A-40G ... Flat screw, 42 ... Scroll groove, 43 ... Side surface, 44 ... Material flow Inlet, 46 ... central portion, 48 ... scroll groove forming surface, 49 ... staying prevention portion, 50 ... screw facing surface, 52 ... screw facing surface, 54 ... guide groove, 56 ... communication hole, 58 ... heater, 60, 60a- 60d ... Nozzle, 62a-62d ... Nozzle hole, 90 ... Plasticizing part, 100, 100a, 100b ... Injection unit, 200 ... Moving mechanism, 210 ... Table, 220 ... Modeling table, 300 ... Control part, 421 ... Inner side wall, 422 ... Outer wall, 423 ... Bottom wall, 424 ... Invitation groove, 425 ... Recess, Dn ... Nozzle hole diameter, G ... Gap, OB ... Three-dimensional structure, OBt ... Upper surface

Claims (7)

A three-dimensional modeling apparatus for manufacturing a three-dimensional structure using a thermoplastic material,
A drive motor;
A flat screw that has a scroll groove forming surface in which a scroll groove is formed and that is rotated by the drive motor; and a screw facing portion that has a communication hole in the center and has a heater that faces the scroll groove forming surface. A plasticizing part that plasticizes the material supplied between the flat screw and the screw facing part by rotation of the flat screw and heating by the heater and converts it into a molten material;
A nozzle for injecting the molten material supplied from the communication hole;
3D modeling device. The three-dimensional modeling apparatus according to claim 1,
A three-dimensional modeling apparatus in which the depth of the scroll groove increases toward the outer peripheral side of the flat screw. The three-dimensional modeling apparatus according to claim 1 or 2,
A three-dimensional modeling apparatus, wherein a plurality of material inlets for receiving the material between the flat screw and the screw facing portion are formed on a side surface of the flat screw. The three-dimensional modeling apparatus according to any one of claims 1 to 3,
The said flat screw is a three-dimensional modeling apparatus which has in the center the stay prevention part which protrudes toward the said communicating hole. The three-dimensional modeling apparatus according to any one of claims 1 to 4,
The scroll groove is defined by an inner wall located radially inside, an outer wall located radially outside, and a bottom wall,
The scroll groove includes a guide groove portion that guides the material toward the outer wall. The three-dimensional modeling apparatus according to any one of claims 1 to 5,
A three-dimensional modeling apparatus in which a recess is formed in the bottom wall of the scroll groove. A three-dimensional modeling method for manufacturing a three-dimensional model using a thermoplastic material,
Plasticizing the material by rotation of a flat screw and heating by a heater to convert it into a molten material;
Injecting the molten material using a nozzle to form the three-dimensional structure; and
3D modeling method.

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