Patent Publication Number: US-2021162642-A1

Title: Plasticizing device

Description:
The present application is based on, and claims priority from JP Application Serial Number 2019-215969, filed on Nov. 29, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a plasticizing device. 
     2. Related Art 
     In JP-A-2009-269182 (Patent Document 1), with respect to a plasticizing and feeding-out device that plasticizes a material and feeds out the resultant as a molding material, a device including a rotor with a spiral groove formed therein and a barrel that abuts an end face of the rotor and has a communication hole at the center is disclosed. 
     When a material in a pellet form is plasticized using the above-mentioned device, by keeping the fluidity of the material in an outer circumferential portion of the rotor lower than the fluidity of the material in a central portion of the rotor, a conveyance force for conveying the material toward the center of the rotor is obtained. The plasticized material in the central portion of the rotor is fed out from the communication hole by this conveyance force, and therefore, if the fluidity of the material in the outer circumferential portion of the rotor cannot be kept low, the feed-out amount of the molding material may become unstable. 
     SUMMARY 
     According to one aspect of the present disclosure, a plasticizing device is provided. The plasticizing device includes a drive motor, a rotor that is rotated by the drive motor and has a groove formed face with a groove along the rotation direction formed therein, a barrel that is opposed to the groove formed face and has a communication hole, a heating portion that heats a material in a pellet form supplied between the groove and the barrel, and a control unit that controls the drive motor and the heating portion so as to plasticize the material supplied between the groove and the barrel and cause the material to flow out from the communication hole. The heating portion has a first heating portion and a second heating portion disposed closer to the communication hole than the first heating portion, and the barrel has a first region and a second region that is closer to the communication hole than the first region. The control unit individually controls the first heating portion and the second heating portion so that a temperature of the second region is higher than a temperature of the first region. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus in a first embodiment. 
         FIG. 2  is a schematic perspective view showing a configuration at a lower face side of a rotor. 
         FIG. 3  is a schematic plan view showing a configuration at a rotor opposed face side of a barrel. 
         FIG. 4  is a IV-IV cross-sectional view of the barrel in  FIG. 1 . 
         FIG. 5  is a cross-sectional view of a barrel in a second embodiment. 
         FIG. 6  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus in a third embodiment. 
         FIG. 7  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus in a fourth embodiment. 
         FIG. 8  is a schematic perspective view showing a configuration at a lower face side of a barrel in the fourth embodiment. 
         FIG. 9  is an explanatory view showing a schematic configuration of an injection molding apparatus as a fifth embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A. First Embodiment 
       FIG. 1  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus  100 . In  FIG. 1 , arrows along X, Y, and Z directions orthogonal to one another are shown. The X, Y, and Z directions are directions along an X axis, a Y axis, and a Z axis that are three spatial axes orthogonal to one another, and each includes both of one side direction along the X, Y, or Z direction, and a direction opposite thereto. The X axis and the Y axis are axes along the horizontal face, and the Z axis is an axis along a vertical line. In also the other drawings, arrows along the X, Y, and Z directions are shown as appropriate. The X, Y, and Z directions in  FIG. 1  and the X, Y, and Z directions in the other drawings indicate the same directions. 
     The three-dimensional shaping apparatus  100  includes a shaping unit  200 , a stage  300 , a moving mechanism  400 , and a control unit  500 . The shaping unit  200  is constituted by a material supply portion  20 , a plasticizing device  90 , and a nozzle  61 . In the three-dimensional shaping apparatus  100 , a material supplied from the material supply portion  20  is plasticized by the plasticizing device  90  under the control of the control unit  500 , whereby a shaping material is formed. The three-dimensional shaping apparatus  100  shapes a three-dimensional shaped article in which the shaping material is laminated on a shaping face  310  by changing a relative position of the nozzle  61  and the shaping face  310  by the moving mechanism  400  while ejecting the formed shaping material toward the shaping face  310  on the stage  300  from the nozzle  61 . A detailed configuration of the shaping unit  200  will be described later. 
     As described above, the moving mechanism  400  changes the relative position of the nozzle  61  and the shaping face  310 . In this embodiment, the moving mechanism  400  supports the stage  300  and changes the relative position of the nozzle  61  and the shaping face  310  by moving the stage  300  with respect to the shaping unit  200 . The change of the relative position of the nozzle  61  with respect to the shaping face  310  is sometimes referred to as “movement of the nozzle  61 ”. 
     The moving mechanism  400  in this embodiment is constituted by a three-axis positioner for moving the stage  300  in three axis directions of the X, Y, and Z directions by driving forces of three motors. Each motor drives under the control of the control unit  500 . The moving mechanism  400  may be configured to change the relative position of the nozzle  61  and the shaping face  310  by moving the shaping unit  200  without moving the stage  300 . Further, the moving mechanism  400  may be configured to change the relative position of the nozzle  61  and the shaping face  310  by moving both the stage  300  and the shaping unit  200 . 
     The control unit  500  is constituted as a computer and includes at least one processor, a memory, and an input/output interface for performing signal input/output to/from the outside. The processor realizes a shaping process for shaping a three-dimensional shaped article by executing a predetermined program stored in the memory. In the shaping process, the control unit  500  appropriately controls the shaping unit  200  and the moving mechanism  400 . The function of the control unit  500  may be partially or entirely realized by a circuit. 
     The material supply portion  20  stores a material in a pellet form for forming a shaping material. The material supply portion  20  is constituted by, for example, a hopper that stores the material. The material supply portion  20  supplies the material stored therein to the plasticizing device  90  through a communication path  22 . In this embodiment, in the material supply portion  20 , a material obtained by molding an ABS resin that is an amorphous resin into a pellet form is stored. The details of the material will be described later. 
     The plasticizing device  90  includes a drive motor  32 , a rotor  40 , and a barrel  50 . The plasticizing device  90  melts at least a part of the material in a solid state supplied from the material supply portion  20  to form a shaping material in a paste form having fluidity, and supplies the formed shaping material to the nozzle  61 . Note that the “melting” not only means that a material having thermoplasticity is transformed into a liquid by being heated to a temperature equal to or higher than the melting point, but also means the “plasticization” that a material having thermoplasticity is softened by being heated to a temperature equal to or higher than the glass transition point so as to exhibit fluidity. The rotor  40  of this embodiment is also referred to as “flat screw” or “scroll”. Further, the barrel  50  is also referred to as “screw facing portion”. In addition, the shaping material is sometimes referred to as “molten material” or “molding material”. 
     The rotor  40  has a substantially columnar shape whose height along its central axis RX is smaller than the diameter. In this embodiment, the rotor  40  is disposed so that the central axis RX becomes parallel to the Z direction. 
     The rotor  40  is housed in a rotor case  31 . An upper face side of the rotor  40  is coupled to the drive motor  32 , and the rotor  40  rotates around the central axis RX in the rotor case  31  by a rotational driving force generated by the drive motor  32 . The drive motor  32  drives under the control of the control unit  500 . 
     In a groove formed face  48  that is a lower face of the rotor  40 , a groove  42  is formed. In this embodiment, the groove  42  is a groove along the rotation direction of the rotor  40 . The above-mentioned communication path  22  of the material supply portion  20  communicates with the groove  42  from a side face of the rotor  40 . 
     The barrel  50  is opposed to the groove formed face  48  of the rotor  40 . Specifically, a rotor opposed face  52  that is an upper face of the barrel  50  and the groove formed face  48  are opposed to each other. A space is formed between the groove  42  of the groove formed face  48  and the rotor opposed face  52 . In this space, the material is supplied from the material supply portion  20 . Specific configurations of the rotor  40  and the groove  42  will be described later. 
     In this embodiment, the barrel  50  is provided with a heating portion  70  and a cooling portion  75 . The heating portion  70  has a first heating portion  71  and a second heating portion  72 , and is provided below the rotor opposed face  52 . The heating portion  70  heats the material supplied between the groove  42  and the barrel  50 . The cooling portion  75  has a refrigerant flow path  76 , an inlet portion  77  for introducing a refrigerant inside the refrigerant flow path  76 , an outlet portion  78  that communicates with the refrigerant flow path  76  and discharges the refrigerant outside the refrigerant flow path  76 , and a refrigerant circulation device  79 . The details of the heating portion  70  and the cooling portion  75  will be described later. 
     The material supplied to the groove  42  of the rotor  40  flows along the groove  42  by the rotation of the rotor  40  while being melted in the groove  42 , and is guided to a central portion  45  of the rotor  40  as the shaping material. The shaping material in a paste form flowing in the central portion  45  is supplied to the nozzle  61  through a communication hole  56  provided at the center of the barrel  50 . 
     The nozzle  61  is provided at a lower part of the barrel  50 . The nozzle  61  has a nozzle flow path  68  and an ejection port  69 . The nozzle flow path  68  is a flow path provided in the nozzle  61 , and one end thereof is coupled to the communication hole  56  in the barrel  50 . The ejection port  69  is a portion with a reduced flow path cross section provided at an end portion which is not coupled to the communication hole  56  of the nozzle flow path  68 . The shaping material flows in the nozzle flow path  68  from the communication hole  56  and is ejected from the ejection port  69 . In this embodiment, an opening shape of the ejection port  69  is a circular shape. The opening shape of the ejection port  69  is not limited to a circular shape, and may be, for example, a square shape or a polygonal shape other than the square shape. 
       FIG. 2  is a schematic perspective view showing a configuration at a lower face side of the rotor  40 . In  FIG. 2 , the position of the central axis RX of the rotor  40  is indicated by an alternate long and short dash line. 
     The central portion  45  of the groove formed face  48  of the rotor  40  is configured as a recess portion to which one end of the groove  42  is coupled. The central portion  45  is opposed to the communication hole  56  of the barrel  50 . In this embodiment, the central portion  45  crosses the central axis RX. 
     The groove  42  of the rotor  40  constitutes a so-called scroll groove. The groove  42  extends in a spiral shape so as to draw an arc toward the outer circumference of the rotor  40  from the central portion  45 . The groove  42  may be, for example, configured to extend in an involute curve shape or in a helical shape. In the groove formed face  48 , a projected streak portion  43  that constitutes a side wall portion of the groove  42  and extends along each groove  42  is provided. 
     The groove  42  is continuous up to a material inflow port  44  formed at a side face of the rotor  40 . The material inflow port  44  is a portion for receiving the material supplied through the communication path  22  of the material supply portion  20 . 
     In  FIG. 2 , an example of the rotor  40  having three grooves  42  and three projected streak portions  43  is shown. The number of grooves  42  or projected streak portions  43  provided in the rotor  40  is not limited to three. In the rotor  40 , only one groove  42  may be provided, or two or more of a plurality of grooves  42  may be provided. Further, an arbitrary number of projected streak portions  43  may be provided in accordance with the number of grooves  42 . 
     In  FIG. 2 , an example of the rotor  40  in which the material inflow port  44  is formed at three sites is shown. The number of material inflow ports  44  provided in the rotor  40  is not limited to three. In the rotor  40 , the material inflow port  44  may be provided at only one site, or may be provided at two or more of a plurality of sites. 
       FIG. 3  is a schematic plan view showing a configuration at the rotor opposed face  52  side of the barrel  50 . At the center of the rotor opposed face  52 , the communication hole  56  for supplying the shaping material to the nozzle  61  is formed. In the rotor opposed face  52 , a plurality of guide grooves  54 , each of which is coupled to the communication hole  56  and extends in a spiral shape toward the outer circumference from the communication hole  56  are formed. The plurality of guide grooves  54  have a function of guiding the shaping material flowing in the central portion  45  of the rotor  40  to the communication hole  56 . In order to allow the shaping material to efficiently reach the communication hole  56 , it is preferred that the guide grooves  54  are formed in the barrel  50 , but the guide grooves  54  need not be formed. 
     As shown in  FIG. 3 , the barrel  50  has a first region RG 1  and a second region RG 2 . The second region RG 2  indicates a region that is closer to the communication hole  56  than the first region RG 1 . In  FIG. 3 , a region outside a broken line and inside an outer edge of the rotor opposed face  52  of the barrel  50  is the first region RG 1 , and a region inside the broken line is the second region RG 2 . That is, the broken line in  FIG. 3  indicates the boundary between the first region RG 1  and the second region RG 2 . In this embodiment, a region inside a circle having a radius that is half the radius of the rotor opposed face  52  is the second region RG 2 , and a region outside the circle is the first region RG 1 . The position of the boundary is not limited to one described above, and may be another position as long as it is a position at which the second region RG 2  becomes a region that is closer to the communication hole  56  than the first region RG 1 . 
     When the material is supplied to the material inflow port  44  of the rotor  40 , the material is guided to the groove  42  and moves toward the central portion  45  while being heated in the groove  42 . As the material approaches the central portion  45 , the material is melted so as to increase the fluidity, and is converted into the shaping material. The shaping material collected in the central portion  45  flows out to the nozzle  61  from the communication hole  56  by an internal pressure generated in the central portion  45 . 
       FIG. 4  is a IV-IV cross-sectional view of the barrel  50  in  FIG. 1 . In  FIG. 4 , the communication hole  56 , the heating portion  70 , and the cooling portion  75  are shown. Further, in  FIG. 4 , the first region RG 1  and the second region RG 2  described above are illustrated. 
     As described above, the heating portion  70  has the first heating portion  71  and the second heating portion  72 . The second heating portion  72  is disposed closer to the communication hole  56  than the first heating portion  71 . Specifically, the shortest distance between the second heating portion  72  and the center of the communication hole  56  in a direction along the XY plane crossing the communication hole  56  is shorter than the shortest distance between the first heating portion  71  and the center of the communication hole  56 . 
     In this embodiment, as the first heating portion  71 , a pair of heaters is disposed across the communication hole  56 , and as the second heating portion  72 , a pair of heaters is disposed across the communication hole  56  aside from the first heating portion  71 . In this embodiment, as the first heating portion  71  and the second heating portion  72 , rod-shaped heaters are disposed. That is, each of the first heating portion  71  and the second heating portion  72  has two rod-shaped heaters. Each heater is disposed such that the longitudinal direction is parallel to the Y direction, and has substantially the same length. The first heating portion  71  and the second heating portion  72  are individually controlled by the control unit  500 . 
     In  FIG. 4 , in the cooling portion  75 , the refrigerant flow path  76 , the inlet portion  77 , and the outlet portion  78  are shown. The refrigerant flow path  76  is disposed along a circumferential direction of the barrel  50  farther from the communication hole  56  than the first heating portion  71 . Specifically, the shortest distance between the refrigerant flow path  76  and the center of the communication hole  56  in the direction along the XY plane crossing the communication hole  56  is farther than the shortest distance between the first heating portion  71  and the center of the communication hole  56 . In this embodiment, the refrigerant flow path  76  along the circumferential direction of the barrel  50  is disposed between the first heating portion  71  and the outer edge of the rotor opposed face  52  in the direction along the XY plane crossing the communication hole  56 . 
     Into the refrigerant flow path  76 , a refrigerant is introduced from the inlet portion  77 . The refrigerant introduced from the inlet portion  77  flows in the refrigerant flow path  76  and is discharged outside from the outlet portion  78 . In this embodiment, as shown in  FIG. 1 , to the inlet portion  77  and the outlet portion  78 , the refrigerant circulation device  79  is coupled. The refrigerant circulation device  79  includes a pump and circulates the refrigerant from the outlet portion  78  to the inlet portion  77 . The refrigerant circulation device  79  is controlled by the control unit  500 . 
     The control unit  500  controls the first heating portion  71  and the second heating portion  72  so that the temperature of the second region RG 2  is higher than the temperature of the first region RG 1 . Further, in this embodiment, the control unit  500  controls the first heating portion  71  and the second heating portion  72  and also controls the refrigerant circulation device  79  so as to circulate the refrigerant in the refrigerant flow path  76 . According to this, in the barrel  50 , a portion farther from the communication hole  56  than the first heating portion  71  is cooled by the refrigerant. That is, as compared with a case where the refrigerant flow path  76  is not provided, the temperature of an outer circumferential portion of the barrel  50  can be kept lower. By controlling the heating portion  70  and the cooling portion  75  in this manner, the fluidity of the material in the first region RG 1  is kept lower than the fluidity of the material in the second region RG 2 . That is, in the outer circumferential portion of the barrel  50 , the fluidity of the material is kept low. 
     In this embodiment, the control unit  500  controls the heating portion  70  so as to adjust the temperature of the first region RG 1  to a temperature lower than the glass transition temperature Tg of the ABS resin that is the material and adjust the temperature of the second region RG 2  to a temperature equal to or higher than the glass transition temperature Tg. In this embodiment, specifically, the glass transition temperature of the ABS resin material is 111° C., and the temperature of the first heating portion  71  is controlled to 210° C., and the temperature of the second heating portion  72  is controlled to 60° C. Further, the control unit  500  controls the refrigerant circulation device  79  so that the temperature of the refrigerant in each of the inlet portion  77  and the outlet portion  78  of the refrigerant flow path  76  is 15° C. As described above, the ABS resin is an amorphous resin, and therefore, by controlling the temperatures of the first region RG 1  and the second region RG 2  based on the glass transition temperature Tg, the fluidity of the material in each region can be appropriately controlled. Note that the glass transition temperature is sometimes referred to as “glass transition point”. 
     According to the plasticizing device  90  of this embodiment described above, the control unit  500  individually controls the first heating portion  71  and the second heating portion  72  disposed closer to the communication hole  56  than the first heating portion  71  so that the temperature of the second region RG 2  that is closer to the communication hole  56  than the first region RG 1  is higher than the temperature of the first region RG 1 . According to this, the fluidity of the material in the first region RG 1  is kept lower than the fluidity of the material in the second region RG 2 . Therefore, the feed-out amount of the shaping material to be fed out from the communication hole  56  becomes stable. 
     Further, in this embodiment, the first heating portion  71  and the second heating portion  72  are provided in the barrel  50 . Therefore, as compared with a case where the first heating portion  71  and the second heating portion  72  are provided in the rotor  40  that rotates, the feed-out amount of the shaping material can be stabilized with a simple configuration. 
     Further, in this embodiment, as the first heating portion  71 , a pair of heating portions is disposed across the communication hole  56 , and as the second heating portion  72 , a pair of heating portions is disposed across the communication hole  56 . According to this, the barrel  50  can be heated symmetrically across the communication hole  56  by the first heating portion  71  and the second heating portion  72 . Therefore, the temperature of the second region RG 2  can be made higher than the temperature of the first region RG 1  by simple control. 
     Further, in this embodiment, the plasticizing device  90  has the refrigerant flow path  76 , the inlet portion  77 , and the outlet portion  78  provided along the circumferential direction of the barrel  50  farther from the communication hole  56  than the first heating portion  71 . Therefore, by allowing the refrigerant to flow in the refrigerant flow path  76 , the fluidity of the material can be kept lower in the outer circumferential portion of the barrel  50 . 
     Further, in this embodiment, the control unit  500  controls the heating portion  70  so as to adjust the temperature of the first region RG 1  to a temperature lower than the glass transition temperature Tg of the ABS resin material that is an amorphous resin and adjust the temperature of the second region RG 2  to a temperature equal to or higher than the glass transition temperature Tg. Therefore, when an amorphous resin is used as the material, the fluidity of the material in the first region RG 1  can be more effectively kept low, and the fluidity of the material in the second region RG 2  can be more effectively increased. 
     Here, the material of a three-dimensional shaped article to be used in the three-dimensional shaping apparatus  100  described above will be described. In the three-dimensional shaping apparatus  100 , for example, a three-dimensional shaped article can be shaped using, as a main material, any of various materials such as a material having thermoplasticity, a metal material, and a ceramic material. Here, the “main material” means a principal material for forming the shape of the three-dimensional shaped article and refers to a material whose content ratio is 50 wt % or more in the three-dimensional shaped article. In the above-mentioned shaping material, a material obtained by melting such a main material singly, or a material formed into a paste by melting a part of the components contained together with the main material is included. 
     When a material having thermoplasticity is used as the main material, the shaping material is formed by plasticizing the material in the plasticizing device  90 . 
     As the material having thermoplasticity, for example, a material obtained by molding the following thermoplastic resin material into a pellet form can be used. 
     Examples of Thermoplastic Resin Material 
     general-purpose engineering plastics such as a polypropylene resin (PP), a polyethylene resin (PE), a polyacetal resin (POM), a polyvinyl chloride resin (PVC), a polyamide resin (PA), an acrylonitrile-butadiene-styrene resin (ABS), a polylactic acid resin (PLA), a polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate, and engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyether ether ketone 
     In the material having thermoplasticity, a pigment, a metal, a ceramic, or other than these, an additive such as a wax, a flame retardant, an antioxidant, or a heat stabilizer, or the like may be mixed. In that case, a material obtained by mixing the above-mentioned thermoplastic resin material with the additive or the like and molding the mixture into a pellet form can be used as the material having thermoplasticity. The material having thermoplasticity is converted into a plasticized and molten state by the rotation of the rotor  40  and the heating by the heating portion  70  in the plasticizing device  90 . It is desirable that the material having thermoplasticity is injected from the nozzle  61  in a state of being completely melted by heating to a temperature equal to or higher than the glass transition point thereof. The shaping material formed by melting the material having thermoplasticity is cured by decreasing the temperature after being ejected from the nozzle  61 . In order to eject the material in a completely melted state, a heater may be provided around the nozzle  61 . 
     In the three-dimensional shaping apparatus  100 , in place of the above-mentioned material having thermoplasticity, for example, the following metal material may be used as the main material. In that case, it is desirable that a powder material obtained by powdering the following metal material and a component that melts when forming the shaping material are mixed and molded into a pellet form, and the resulting material is put in the plasticizing device  90 . 
     Examples of Metal Material 
     single metals of magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), and nickel (Ni), or alloys containing one or more of these metals 
     Examples of the Above Alloy 
     a maraging steel, a stainless steel, cobalt-chromium-molybdenum, a titanium alloy, a nickel alloy, an aluminum alloy, a cobalt alloy, and a cobalt-chromium alloy 
     In the three-dimensional shaping apparatus  100 , in place of the above-mentioned metal material, a ceramic material can be used as the main material. As the ceramic material, for example, an oxide ceramic such as silicon dioxide, titanium dioxide, aluminum oxide, or zirconium oxide, a non-oxide ceramic such as aluminum nitride, or the like can be used. When a metal material or a ceramic material as described above is used as the main material, the shaping material ejected in the shaping face  310  may be cured by sintering. 
     The metal material or the ceramic material to be put in the material supply portion  20  as the material may be a mixed material obtained by mixing multiple types of single metal powders or alloy powders or ceramic material powders and molding the mixture into a pellet form. Further, the powder material of the metal material or the ceramic material may be coated with, for example, a thermoplastic resin as exemplified above or a thermoplastic resin other than these. In that case, the material may be configured to exhibit fluidity by melting the thermoplastic resin in the plasticizing device  90 . 
     It is also possible to use a material obtained by adding, for example, a solvent as described below to the metal material or the ceramic material and shaping the resultant into a pellet form. As the solvent, one type or a combination of two or more types selected from the following solvents can be used. 
     Examples of Solvent 
     water; (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetate esters such as ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, and iso-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene, ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl n-butyl ketone, diisopropyl ketone, and acetyl acetone; alcohols such as ethanol, propanol, and butanol; tetra-alkyl ammonium acetates; sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine-based solvents such as pyridine, γ-picoline, and 2,6-lutidine; tetra-alkyl ammonium acetates (for example, tetra-butyl ammonium acetate, etc.); ionic liquids such as butyl carbitol acetate, and the like 
     In addition thereto, it is also possible to use a material obtained by adding, for example, a binder as described below to the metal material or the ceramic material and shaping the resultant into a pellet form. 
     Examples of Binder 
     an acrylic resin, an epoxy resin, a silicone resin, a cellulosic resin, or another synthetic resin, or PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), or other thermoplastic resins 
     B. Second Embodiment 
       FIG. 5  is a cross-sectional view of a barrel  50   b  provided in a plasticizing device  90   b  in a second embodiment. In  FIG. 5 , in the same manner as the cross-sectional view of the barrel  50  of the first embodiment shown in  FIG. 4 , a communication hole  56 , a heating portion  70   b,  a cooling portion  75 , a first region RG 1 , and a second region RG 2  are shown. Further, the plasticizing device  90   b  is included in a three-dimensional shaping apparatus  100  in the same manner as in the first embodiment. In the plasticizing device  90   b,  portions that are not particularly described are the same as those of the first embodiment. 
     The heating portion  70   b  has a first heating portion  71   b  and a second heating portion  72   b.  In this embodiment, the first heating portion  71   b  and the second heating portion  72   b  are both annularly disposed along a circumferential direction of a rotor  40 . In this embodiment, specifically, the first heating portion  71   b  and the second heating portion  72   b  are aluminum nitride heaters formed in an annular shape. In another embodiment, the first heating portion  71   b  and the second heating portion  72   b  may be, for example, heaters using another ceramic such as silicon nitride, or may be heaters in which a heating wire is formed in an annular shape. 
     According also to the plasticizing device  90   b  of the second embodiment described above, the fluidity of the material in the first region RG 1  is kept lower than the fluidity of the material in the second region RG 2 . In particular, in this embodiment, the first heating portion  71   b  and the second heating portion  72   b  are annularly disposed along the circumferential direction of the rotor  40 . Therefore, the fluidity of the material in an outer circumferential portion of the barrel  50   b  can be kept low by simple control. 
     C. Third Embodiment 
       FIG. 6  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus  100   c  in a third embodiment. A plasticizing device  90   c  included in a shaping unit  200   c  of the third embodiment includes a temperature measurement portion  81  unlike the first embodiment. In the plasticizing device  90   c  and the three-dimensional shaping apparatus  100   c,  portions that are not particularly described are the same as those of the first embodiment. 
     The temperature measurement portion  81  measures temperatures of a first region RG 1  and a second region RG 2 . In this embodiment, the temperature measurement portion  81  has a thermocouple that measures the temperature of the first region RG 1  and a thermocouple that measures the temperature of the second region RG 2 . In another embodiment, for example, the temperature measurement portion  81  may include a contactless sensor such as a radiation thermometer that measures the temperature of the first region RG 1  and the temperature of the second region RG 2 . 
     In this embodiment, a control unit  500  controls a first heating portion  71  and a second heating portion  72  according to the temperatures measured by the temperature measurement portion  81 . For example, when the temperature of the first region RG 1  is higher than the glass transition temperature Tg of the material, the control unit  500  may decrease the output of the second heating portion  72 , and when the temperature of the second region RG 2  is lower than a target temperature, the control unit  500  may increase the output of the first heating portion  71 . In that case, the target temperature can be determined as an arbitrary temperature exceeding the glass transition temperature Tg. In another case, a value to serve as a reference when the first heating portion  71  and the second heating portion  72  are controlled according to the measured temperatures may be predetermined from a temperature distribution or the like. 
     According also to the plasticizing device  90   c  of the third embodiment described above, the fluidity of the material in the first region RG 1  is kept lower than the fluidity of the material in the second region RG 2 . In particular, in this embodiment, the temperatures of the first region RG 1  and the second region RG 2  can be more accurately adjusted according to the temperatures measured by the temperature measurement portion  81 . 
     D. Fourth Embodiment 
       FIG. 7  is an explanatory view showing a schematic configuration of a three-dimensional shaping apparatus  100   d  in a fourth embodiment.  FIG. 8  is a schematic perspective view showing a configuration at a lower face side of a barrel  50   d.  As shown in  FIGS. 7 and 8 , a plasticizing device  90   d  of the fourth embodiment includes a heating portion  70   d  annularly disposed along a circumferential direction of a rotor  40 . The heating portion  70   d  of this embodiment does not have the first heating portion  71  and the second heating portion  72  unlike the first embodiment. 
     The heating portion  70   d  is one aluminum nitride heater formed in an annular shape. In this embodiment, the heating portion  70   d  is disposed at a lower face of the barrel  50   d  so as to surround a nozzle  61 . The heating portion  70   d  may be housed in a case, and for example, a lower face or an outer circumference of the heating portion  70   d  may be covered with an insulating material. In another embodiment, the heating portion  70   d  may be embedded inside the barrel  50   d.  Further, the heating portion  70   d  may be, for example, a heater using another ceramic such as silicon nitride, or may be a heater in which a heating wire is formed in an annular shape. 
     Also in this embodiment, a control unit  500  controls the heating portion  70   d  so that a temperature of a second region RG 2  is higher than a temperature of a first region RG 1 . Further, the control unit  500  controls the heating portion  70   d,  and also controls a refrigerant circulation device  79  so as to circulate a refrigerant in a refrigerant flow path  76  disposed in the barrel  50   d.  The refrigerant flow path  76  is disposed along a circumferential direction of the barrel  50   d  farther from a communication hole  56  than the heating portion  70   d.  That is, in this embodiment, the refrigerant flow path  76  along the circumferential direction of the barrel  50   d  is disposed between the heating portion  70   d  and an outer edge of a rotor opposed face  52  in the direction along the XY plane crossing the communication hole  56 . 
     Also in this embodiment, as the material, an ABS resin formed into a pellet form is used. The control unit  500  controls the heating portion  70   d  so as to adjust the temperature of the first region RG 1  to a temperature lower than the glass transition temperature Tg of the ABS resin that is the material and adjust the temperature of the second region RG 2  to a temperature equal to or higher than the glass transition temperature Tg. Specifically, the glass transition temperature of the ABS resin material is 111° C., and the temperature of the heating portion  70   d  is controlled to 250° C. Further, the control unit  500  controls the refrigerant circulation device  79  so that the temperature of the refrigerant in each of an inlet portion  77  and an outlet portion  78  of the refrigerant flow path  76  is 15° C. in the same manner as in the first embodiment. 
     According also to the plasticizing device  90   d  of this embodiment described above, the control unit  500  controls the heating portion  70   d  annularly disposed along the circumferential direction of the rotor  40  so that the temperature of the second region RG 2  that is closer to the communication hole  56  than the first region RG 1  is higher than the temperature of the first region RG 1 . According to this, the fluidity of the material in the first region RG 1  is kept lower than the fluidity of the material in the second region RG 2 . Therefore, the feed-out amount of the shaping material to be fed out from the communication hole  56  can be stabilized. 
     Further, in this embodiment, the plasticizing device  90   d  has the refrigerant flow path  76 , the inlet portion  77 , and the outlet portion  78  provided along the circumferential direction of the barrel  50   d  farther from the communication hole  56  than the heating portion  70   d.  Therefore, by allowing the refrigerant to flow in the refrigerant flow path  76 , the fluidity of the material can be kept lower in the outer circumferential portion of the barrel  50   d.    
     Further, in this embodiment, the control unit  500  controls the heating portion  70   d  so as to adjust the temperature of the first region RG 1  to a temperature lower than the glass transition temperature Tg of the ABS resin material that is an amorphous resin and adjust the temperature of the second region RG 2  to a temperature equal to or higher than the glass transition temperature Tg. Therefore, when an amorphous resin is used as the material, the fluidity of the material in the first region RG 1  can be more effectively kept low, and the fluidity of the material in the second region RG 2  can be more effectively increased. 
     E. Fifth Embodiment 
       FIG. 9  is an explanatory view showing a schematic configuration of an injection molding apparatus  800  as a fifth embodiment of the present disclosure. The injection molding apparatus  800  of this embodiment includes a plasticizing device  90 , a nozzle  61 , an injection control mechanism  810 , a mold portion  830 , and a mold clamping device  840 . The configuration of the plasticizing device  90  is the same as that in the first embodiment unless otherwise described. 
     As described in the first embodiment, the plasticizing device  90  has a rotor  40  and a barrel  50 . To a communication hole  56  of the barrel  50  of this embodiment, the below-mentioned injection cylinder  811  is coupled. The plasticizing device  90  plasticizes at least a part of a material supplied to a groove  42  of the rotor  40  under the control of a control unit  850  to form a molten material in a paste form having fluidity, and guides the molten material to the injection control mechanism  810  from the communication hole  56 . 
     The barrel  50  of this embodiment includes a first heating portion  71  and a second heating portion  72  in the same manner as in the first embodiment. Further, the barrel  50  of this embodiment includes a cooling portion  75  in the same manner as in the first embodiment. In  FIG. 9 , in order to facilitate the understanding of the configuration, illustration of the configuration other than a refrigerant flow path  76  in the cooling portion  75  is omitted. 
     The injection control mechanism  810  includes the injection cylinder  811 , a plunger  812 , and a plunger drive portion  813 . The injection control mechanism  810  has a function of injecting the molten material in the injection cylinder  811  into the below-mentioned cavity Cv. The injection control mechanism  810  controls the injection amount of the molten material from the nozzle  61  under the control of the control unit  850 . The injection cylinder  811  is a member in a substantially cylindrical shape coupled to the communication hole  56  of the barrel  50 , and includes the plunger  812  therein. The plunger  812  slides inside the injection cylinder  811  and pressure-feeds the molten material in the injection cylinder  811  to the nozzle  61  coupled to the plasticizing device  90 . The plunger  812  is driven by the plunger drive portion  813  constituted by a motor. 
     The mold portion  830  includes a movable mold  831  and a fixed mold  832 . The movable mold  831  and the fixed mold  832  are provided so as to face each other, and the cavity Cv that is a space corresponding to the shape of a molded product is provided therebetween. Into the cavity Cv, the molten material is pressure-fed by the injection control mechanism  810  and injected through the nozzle  61 . 
     The mold clamping device  840  includes a mold drive portion  841 , and has a function of opening and closing the movable mold  831  and the fixed mold  832 . The mold clamping device  840  opens and closes the mold portion  830  by driving the mold drive portion  841  so as to move the movable mold  831  under the control of the control unit  850 . 
     The injection molding apparatus  800  of this embodiment described above includes the plasticizing device  90  having the same configuration as that in the first embodiment as described above. Therefore, the feed-out amount of the shaping material to be fed out from the communication hole  56  can be stabilized. 
     F. Other Embodiments 
     (F-1) In the above-mentioned embodiments, the first heating portion  71  and the second heating portion  72  are provided in the barrel  50 . On the other hand, for example, either one of the first heating portion  71  and the second heating portion  72  may be provided in the rotor  40 . Further, both the first heating portion  71  and the second heating portion  72  may be provided in the rotor  40 . In addition, also the heating portion  70   d  in the fourth embodiment may be provided in the rotor  40  similarly. 
     (F-2) In the above-mentioned embodiments, the first heating portion  71  and the second heating portion  72  need not be rod-shaped or annular heaters. For example, they may be flat plate-shaped heaters or heaters having an arc-shaped portion along the circumferential direction of the rotor  40 . Further, each of the heaters may be provided in a pair. 
     (F-3) In the above-mentioned embodiments, the cooling portion  75  includes the refrigerant circulation device  79 . On the other hand, the cooling portion  75  need not include the refrigerant circulation device  79 . For example, the cooling portion  75  may include a refrigerant supply portion that supplies a refrigerant to the refrigerant flow path  76 , a tube that communicates with the inlet portion  77  and a tube that communicates with the outlet portion  78  without including the refrigerant circulation device  79 . In that case, from the refrigerant supply portion, the refrigerant may be continuously supplied to the refrigerant flow path  76  through the tube that communicates with the inlet portion  77 , and also the refrigerant in the refrigerant flow path  76  may be continuously discharged outside from the tube that communicates with the outlet portion  78 . 
     (F-4) In the above-mentioned embodiments, the plasticizing device  90  includes the cooling portion  75 . On the other hand, the plasticizing device  90  need not include the cooling portion  75 . 
     (F-5) In the above-mentioned embodiments, the control unit  500  controls the heating portion  70  so as to adjust the temperature of the first region RG 1  to a temperature lower than the glass transition temperature of the material and adjust the temperature of the second region RG 2  to a temperature equal to or higher than the glass transition temperature. On the other hand, if the temperature of the second region RG 2  is adjusted so as to be higher than the temperature of the first region RG 1 , the temperature of the first region RG 1  or the temperature of the second region RG 2  need not be adjusted using the glass transition temperature as a reference. For example, when a material having a melting point is used, the temperature of the first region RG 1  may be adjusted to a temperature lower than the melting point and the temperature of the second region RG 2  may be adjusted to a temperature equal to or higher than the melting point. 
     G. Other Aspects 
     The present disclosure is not limited to the above-mentioned embodiments, but can be realized in various aspects without departing from the gist thereof. For example, the present disclosure can be realized as the following aspects. The technical features in the above-mentioned respective embodiments corresponding to technical features in the respective aspects described below may be appropriately replaced or combined for solving part or all of the problems of the present disclosure or achieving part or all of the effects of the present disclosure. Further, the technical features may be appropriately deleted unless they are described as being essential in the present specification. 
     (1) According to a first aspect of the present disclosure, a plasticizing device is provided. The plasticizing device includes a drive motor, a rotor that is rotated by the drive motor and has a groove formed face with a groove formed therein, a barrel that is opposed to the groove formed face and has a communication hole, a heating portion that heats a material in a pellet form supplied between the groove and the barrel, and a control unit that controls the drive motor and the heating portion so as to plasticize the material supplied between the groove and the barrel and cause the material to flow out from the communication hole. The heating portion has a first heating portion and a second heating portion disposed closer to the communication hole than the first heating portion, and the barrel has a first region and a second region that is closer to the communication hole than the first region. The control unit individually controls the first heating portion and the second heating portion so that a temperature of the second region is higher than a temperature of the first region. 
     According to such an aspect, the fluidity of the material in the first region is kept lower than the fluidity of the material in the second region. Therefore, the feed-out amount of the shaping material to be fed out from the communication hole becomes stable. 
     (2) In the plasticizing device according to the above aspect, the first heating portion and the second heating portion may be provided in the barrel. According to such an aspect, as compared with a case where the first heating portion and the second heating portion are provided in the rotor that rotates, the feed-out amount of the shaping material can be stabilized with a simple configuration. 
     (3) In the plasticizing device according to the above aspect, as the first heating portion, a pair of heating portions may be disposed across the communication hole, and as the second heating portion, a pair of heating portions may be disposed across the communication hole. According to such an aspect, the barrel can be heated symmetrically across the communication hole by the first heating portion and the second heating portion. Therefore, the temperature of the second region can be made higher than the temperature of the first region by simple control. 
     (4) In the plasticizing device according to the above aspect, the first heating portion and the second heating portion may be annularly disposed along a circumferential direction of the rotor. According to such an aspect, the fluidity of the material in an outer circumferential portion of the barrel can be kept low by simple control. 
     (5) In the plasticizing device according to the above aspect, a temperature measurement portion that measures temperatures of the first region and the second region may be included, and the control unit may control the first heating portion and the second heating portion according to the temperatures measured by the temperature measurement portion. According to such an aspect, the temperatures of the first region and the second region can be more accurately adjusted according to the temperatures measured by the temperature measurement portion. 
     (6) In the plasticizing device according to the above aspect, a refrigerant flow path disposed along a circumferential direction of the barrel farther from the communication hole than the first heating portion, an inlet portion that communicates with the refrigerant flow path and introduces a refrigerant inside the refrigerant flow path, and an outlet portion that communicates with the refrigerant flow path and discharges the refrigerant outside the refrigerant flow path may be included. According to such an aspect, by allowing the refrigerant to flow in the refrigerant flow path, the fluidity of the material can be kept lower in the outer circumferential portion of the barrel. 
     (7) In the plasticizing device according to the above aspect, the material may be an amorphous resin, and the control unit may control the heating portion so as to adjust the temperature of the first region to a temperature lower than a glass transition temperature of the material and adjust the temperature of the second region to a temperature equal to or higher than the glass transition temperature. According to such an aspect, when an amorphous resin is used as the material, the fluidity of the material in the first region can be more effectively kept low, and the fluidity of the material in the second region can be more effectively increased. 
     (8) According to a second aspect of the present disclosure, a plasticizing device is provided. The plasticizing device includes a drive motor, a rotor that is rotated by the drive motor and has a groove formed face with a groove formed therein, a barrel that is opposed to the groove formed face and has a communication hole, a heating portion that is annularly disposed along a circumferential direction of the rotor, and heats a material in a pellet form supplied between the groove and the barrel, and a control unit that controls the drive motor and the heating portion so as to plasticize the material supplied between the groove and the barrel and cause the material to flow out from the communication hole. The barrel has a first region and a second region that is closer to the communication hole than the first region, and the control unit controls the heating portion so that a temperature of the second region is higher than a temperature of the first region. 
     According to such an aspect, the fluidity of the material in the first region is kept lower than the fluidity of the material in the second region. Therefore, the feed-out amount of the shaping material to be fed out from the communication hole becomes stable. 
     The present disclosure is not limited to the above-mentioned plasticizing devices, and can be realized in various modes. For example, it can be realized in aspects of a method for plasticizing a material, a method for controlling a plasticizing device, a three-dimensional shaping apparatus, an injection molding apparatus, etc.