Patent Publication Number: US-2023158747-A1

Title: Three-dimensional shaping device and method for manufacturing three-dimensional shaped object

Description:
The present application is based on, and claims priority from JP Application Serial Number 2021-191206, filed Nov. 25, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a three-dimensional shaping device and a method for manufacturing a three-dimensional shaped object. 
     2. Related Art 
     JP-A-2006-192710 (Patent Literature 1) discloses a technique in which a molten thermoplastic material is extruded onto a base from an extrusion nozzle that performs scanning in accordance with preset shape data, and a three-dimensional object is formed by further stacking a molten material on a material cured on the base. JP-T-2010-530326 (Patent Literature 2) discloses a three-dimensional shaping device provided with an edge cleaning assembly having a flicker plate and a brush. The three-dimensional shaping device cleans an extrusion head by bringing the extrusion head into contact with the flicker plate and the brush. 
     When a device in which a molten thermoplastic material is extruded from a nozzle and stacked as disclosed in Patent Literature 1 is used for a certain period of time, the thermoplastic material may be deposited in a nozzle flow path or a nozzle opening, and nozzle clogging may occur unexpectedly. In order to prevent such unexpected nozzle clogging, there is a demand for a technique in which the use of a nozzle can be managed. When nozzle clogging occurs, it is effective to clean the nozzle as disclosed in Patent Literature 2. However, a waste material adhering to a cleaning mechanism may adhere to the nozzle again to induce nozzle clogging. 
     SUMMARY 
     According to a first aspect of the present disclosure, there is provided a three-dimensional shaping device. The three-dimensional shaping device includes an ejection unit that is provided with a nozzle and a plasticizing mechanism configured to plasticize a plasticizing material to generate a shaping material and that is configured to eject the shaping material from the nozzle; a stage on which the shaping material is stacked; a drive unit configured to change a relative position between the ejection unit and the stage; a cleaning mechanism provided with a brush and a blade; and a control unit configured to execute a cleaning processing of cleaning the nozzle and control the ejection unit and the drive unit to stack a layer on the stage. The brush and the blade are disposed at a height at which the brush and the blade are contactable with the nozzle, and the brush and the blade have a melting point higher than a plasticizing temperature of the plasticizing material and a hardness lower than a hardness of the nozzle. The control unit executes a cleaning operation of bringing at least one of the brush and the blade into contact with the nozzle by causing the nozzle to reciprocate in a manner in which the nozzle crosses the cleaning mechanism for a plurality of times in the cleaning processing, the control unit causes the nozzle to reciprocate such that the nozzle comes into contact with the brush or the blade at different positions in the cleaning operation, and the control unit records at least one of material information on a type of the plasticizing material, a cumulative ejection amount of the shaping material ejected from the nozzle, and a use time of the nozzle in association with the nozzle. 
     According to a second aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional shaped object in a three-dimensional shaping device. The three-dimensional shaping device includes an ejection unit that is provided with a nozzle and a plasticizing mechanism configured to plasticize a plasticizing material to generate a shaping material and that is configured to eject the shaping material from the nozzle; a stage on which the shaping material is stacked; a drive unit configured to change a relative position between the ejection unit and the stage; and a cleaning mechanism provided with a brush and a blade. The brush and the blade are disposed at a height at which the brush and the blade are contactable with the nozzle, and the brush and the blade have a melting point higher than a plasticizing temperature of the plasticizing material and a hardness lower than a hardness of the nozzle. The manufacturing method includes: a stacking step of stacking a layer on the stage by controlling the ejection unit and the drive unit; a cleaning step of executing a cleaning operation of bringing at least one of the brush and the blade into contact with the nozzle by causing the nozzle to reciprocate in a manner in which the nozzle crosses the cleaning mechanism for a plurality of times. In the cleaning step, the nozzle reciprocates such that the nozzle comes into contact with the brush or the blade at different positions in the cleaning operation, and at least one of material information on a type of the plasticizing material, a cumulative ejection amount of the shaping material ejected from the nozzle, and a use time of the nozzle is recorded in association with the nozzle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram showing a schematic configuration of a three-dimensional shaping device according to a first embodiment. 
         FIG.  2    is a diagram showing a schematic configuration of an ejection unit. 
         FIG.  3    is a schematic perspective view showing a screw. 
         FIG.  4    is a top view showing a barrel. 
         FIG.  5    is a diagram illustrating attachment of a nozzle to and detachment of the nozzle from a through hole. 
         FIG.  6    is a diagram showing an example of nozzle information. 
         FIG.  7    is a diagram illustrating a schematic configuration of a cleaning mechanism. 
         FIG.  8    is a flowchart showing a three-dimensional shaping processing representing a method for manufacturing a three-dimensional shaped object. 
         FIG.  9    is a diagram showing an example of a cleaning condition table. 
         FIG.  10    is a diagram illustrating a reciprocating operation of the nozzle. 
         FIG.  11    is a diagram illustrating another example of the reciprocating operation of the nozzle. 
         FIG.  12    is a diagram illustrating another example of the reciprocating operation of the nozzle. 
         FIG.  13    is a diagram illustrating another example of the reciprocating operation of the nozzle. 
         FIG.  14    is a diagram illustrating another example of the reciprocating operation of the nozzle. 
         FIG.  15    is a flowchart showing a three-dimensional shaping processing according to a second embodiment. 
         FIG.  16    is a diagram showing an example of a cleaning condition table. 
         FIG.  17    is a diagram showing a correspondence relationship between the number of cleaning times and a cleaning interval according to a third embodiment. 
         FIG.  18    is a diagram showing a correspondence relationship between the number of cleaning times and a cleaning strength according to a fourth embodiment. 
         FIG.  19    is a flowchart showing a timing change processing according to a fifth embodiment. 
         FIG.  20    is a flowchart showing a cleaning condition change processing according to a sixth embodiment. 
         FIG.  21    is a flowchart showing a nozzle information update processing according to a seventh embodiment. 
         FIG.  22    is a diagram showing a schematic configuration of a three-dimensional shaping device according to an eighth embodiment. 
         FIG.  23    is a diagram showing a schematic configuration of a three-dimensional shaping device according to a ninth embodiment. 
         FIG.  24    is a diagram showing a schematic configuration of an ejection unit according to the ninth embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     A. First Embodiment 
       FIG.  1    is a diagram showing a schematic configuration of a three-dimensional shaping device  10  according to a first embodiment.  FIG.  1    shows arrows along X, Y, and Z directions that are orthogonal to one another. 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 the X, Y, and Z directions respectively include directions on one side along the X axis, the Y axis, and the Z axis and directions opposite thereto. The X axis and the Y axis are axes along a horizontal plane, and the Z axis is an axis along a vertical line. −Z direction is a vertical direction, and +Z direction is a direction opposite to the vertical direction. −Z direction is also referred to as “lower”, and +Z direction is also referred to as “upper”. X, Y, and Z directions in  FIG.  1    and X, Y, and Z directions in other drawings represent the same directions. 
     The three-dimensional shaping device  10  according to the present embodiment includes an ejection unit  100 , a material storage unit  20 , a housing  110 , a drive unit  210 , a stage  220 , a cleaning mechanism  250 , a control unit  300 , and a display device  400  serving as a notification unit. 
     The ejection unit  100  includes a plasticizing mechanism  30  that plasticizes at least a part of a plasticizing material supplied from the material storage unit  20  to generate a shaping material, and a nozzle  60 . The ejection unit  100  ejects the shaping material plasticized by the plasticizing mechanism  30  from the nozzle  60  toward the stage  220 . The ejection unit  100  is also referred to as an ejection head, a discharge unit, a discharge head, an extrusion unit, an extrusion head, or is simply referred to as a head. In the present specification, “ejection” also includes the meaning of “discharge” or “extrusion”. 
     The housing  110  has a shaping space  111  therein. The stage  220  on which the shaping material is stacked is disposed in the shaping space  111 . The housing  110  may be provided with, for example, an opening portion that allows the shaping space  111  to communicate with the outside, a door that opens and closes the opening portion, and the like. By opening the door to bring the opening portion into an open state, a user can take out a shaped object shaped on the stage  220  from the opening portion. 
     The drive unit  210  changes a relative position between the ejection unit  100  and the stage  220 . In the present embodiment, the drive unit  210  includes a first drive unit  211  that moves the stage  220  along the Z direction, and a second drive unit  212  that moves the ejection unit  100  along the X direction and the Y direction. The first drive unit  211  is implemented as an elevating device, and includes a motor for moving the stage  220  in the Z direction. The second drive unit  212  is implemented as a horizontal conveyance device, and includes a motor for moving the ejection unit  100  in a sliding manner along the X direction and a motor for moving the ejection unit  100  in a sliding manner along the Y direction. Each motor is driven under the control of the control unit  300 . In another embodiment, the drive unit  210  may be configured to move the stage  220  or the ejection unit  100  in three directions of X, Y, and Z, or may be configured to move the stage  220  along the X direction and the Y direction and move the ejection unit  100  along the Z direction. 
     The cleaning mechanism  250  includes a brush  251  and a blade  252  for cleaning the nozzle  60 . The cleaning mechanism  250  is disposed in a region different from the stage  220  in a horizontal direction. The cleaning mechanism  250  is disposed at a height at which the brush  251  and the blade  252  can come into contact with the nozzle  60  in the vertical direction. In the present embodiment, the cleaning mechanism  250  is coupled to the housing  110  via a support portion  280 . A purge waste container  260  is provided below the cleaning mechanism  250 . A waste material removed by the cleaning mechanism  250  falls into and is collected in the purge waste container  260 . The blade  252  is also referred to as a flicker plate. The cleaning mechanism  250  is also referred to as a tip wipe assembly. 
     The control unit  300  is implemented by a computer including one or more processors  310 , a storage unit  320  including a main storage device and an auxiliary storage device, and an input and output interface that performs signal input and output with the outside. In the present embodiment, the processor  310  executes a program stored in the storage unit  320 , so that the control unit  300  can control the ejection unit  100  and the drive unit  210  based on shaping data for shaping a three-dimensional shaped object to perform a three-dimensional shaping processing to be described later and a cleaning processing for cleaning the nozzle. In addition, the control unit  300  has a function of recording at least one of material information on a type of the plasticizing material, a cumulative ejection amount of the shaping material ejected from the nozzle  60 , and a use time of the nozzle  60  in association with the nozzle  60 . The control unit  300  may be implemented by a combination of a plurality of circuits instead of a computer. 
     The display device  400  is coupled to the control unit  300 . The display device  400  includes, for example, a liquid crystal display or an organic EL display. Although the display device  400  is provided in the housing  110  in the present embodiment, the display device  400  may be disposed separately from the housing  110 . 
       FIG.  2    is a diagram showing a schematic configuration of the ejection unit  100 . The ejection unit  100  includes the plasticizing mechanism  30 , the nozzle  60 , and a flow rate adjusting unit  70 . The plasticizing mechanism  30  includes a material conveying mechanism  40  and a heating block  90 . A material stored in the material storage unit  20  is supplied to the ejection unit  100 . Under the control of the control unit  300 , the ejection unit  100  plasticizes at least a part of the material supplied from the material storage unit  20  in the plasticizing mechanism  30  to generate a shaping material, and ejects the generated shaping material onto the stage  220  from the nozzle  60  to stack the shaping material. The material stacked on the stage  220  may be referred to as a stacked material. A three-dimensional shaping method for shaping a three-dimensional shaped object by ejecting a material from the nozzle  60  and stacking the ejected material may be referred to as a material extrusion (ME) method. 
     In the present embodiment, “plasticizing” is a concept including melting, and refers to a change from a solid state to a state having fluidity. Specifically, in a case of a material in which glass transition occurs, the term “plasticizing” refers to setting a temperature of the material to be equal to or higher than a glass transition point. In a case of a material in which no glass transition occurs, the term “plasticizing” refers to setting a temperature of the material to be equal to or higher than a melting point. 
     A material in a state of pellets, powder, or the like is stored in the material storage unit  20  according to the present embodiment. In the present embodiment, a material stored in the material storage unit  20  is a pellet-shaped resin. The material storage unit  20  according to the present embodiment is implemented by a hopper. The material stored in the material storage unit  20  is supplied to the material conveying mechanism  40  of the plasticizing mechanism  30  via a supply path  22  that is provided below the material storage unit  20  in a manner of coupling the material storage unit  20  and the ejection unit  100 . 
     The heating block  90  has a heater  58 . The heater  58  is controlled by the control unit  300 , and is heated to a plasticizing temperature for plasticizing a material. The plasticizing temperature varies depending on a type of a material to be used, and is, for example, a glass transition point or a melting point of the material. When the material is an ABS resin, the plasticizing temperature is set to, for example, about 110° C. which is a glass transition point of the ABS resin. The heating block  90  is provided with a through hole  80 . The through hole  80  is formed to allow attachment and detachment of the nozzle  60 . The material conveying mechanism  40  conveys the shaping material toward a nozzle flow path  61  of the nozzle  60  attached to the through hole  80  of the heating block  90 . The plasticizing mechanism  30  conveys the material supplied from the material storage unit  20  to the material conveying mechanism  40  toward the nozzle flow path  61  of the nozzle  60  using the material conveying mechanism  40 , and plasticizes the material while heating the material using the heat of the heating block  90 . 
     The material conveying mechanism  40  according to the present embodiment includes a screw case  31 , a screw  41  housed in the screw case  31 , and a drive motor  32  that drives the screw  41 . The heating block  90  according to the present embodiment includes a case portion  91  having an opening portion  94 , and a barrel  50  disposed in the case portion  91 . The barrel  50  is provided with a communication hole  56 . The through hole  80  according to the present embodiment is formed by the opening portion  94  and the communication hole  56  communicating with each other. The above-described heater  58  is built in the barrel  50 . The screw  41  according to the present embodiment is a so-called flat screw, and may be referred to as a “scroll”. 
     The screw  41  has a substantially cylindrical shape of which a height in a direction along a central axis RX of the screw  41  is smaller than a diameter. The screw  41  has a groove forming surface  42  on a surface facing the barrel  50  on which screw grooves  45  are formed. The groove forming surface  42  faces a screw facing surface  52  of the barrel  50  which will be described later. The central axis RX according to the present embodiment coincides with a rotation axis of the screw  41 . A configuration of the screw  41  will be described in detail later. 
     The drive motor  32  is coupled to a surface of the screw  41  opposite to the groove forming surface  42 . The drive motor  32  is driven under the control of the control unit  300 . The screw  41  is rotated around the central axis RX by a torque generated by the rotation of the drive motor  32 . The drive motor  32  may not be directly coupled to the screw  41 , and may be coupled to the screw  41  via, for example, a speed reducer. 
     The barrel  50  has the screw facing surface  52  facing the groove forming surface  42  of the screw  41 . The case portion  91  is disposed in a manner of covering a surface of the barrel  50  opposite to the screw facing surface  52 , that is, a lower surface of the barrel  50 . The communication hole  56  and the opening portion  94  described above are provided at positions overlapping the central axis RX of the screw  41 . That is, the through hole  80  is located at a position overlapping the central axis RX. 
     As described above, the nozzle  60  is detachably attached to the through hole  80  of the heating block  90 . The nozzle  60  is also referred to as a nozzle tip. The nozzle  60  is provided with the nozzle flow path  61  described above. The nozzle flow path  61  has a nozzle opening  63  at a tip end of the nozzle  60 , and has an inflow port  65  at a rear end of the nozzle  60 . The nozzle opening  63  is located at a position in the −Z direction of the inflow port  65 . The nozzle  60  according to the present embodiment discharges a material flowing into the nozzle flow path  61  through the through hole  80  and the inflow port  65  from the nozzle opening  63  toward the stage  220 . A heater for heating the material in the nozzle flow path  61  may be provided around the nozzle flow path  61 . 
     The nozzle  60  has a shield  68  above the tip end of the nozzle  60 . More specifically, the shield  68  is disposed between the nozzle opening  63  and the heating block  90  on an outer periphery of the nozzle  60 . The shield  68  has a disk shape along the horizontal direction. The shield  68  prevents the heat of the heating block  90  from being transferred to the stacked material. 
     The flow rate adjusting unit  70  changes an opening degree of the nozzle flow path  61  by rotating the flow rate adjusting unit  70  in the nozzle flow path  61 . In the present embodiment, the flow rate adjusting unit  70  is implemented by a butterfly valve. The flow rate adjusting unit  70  is driven by a valve drive unit  75  under the control of the control unit  300 . The valve drive unit  75  is implemented by, for example, a stepping motor. The control unit  300  can adjust a flow rate of the shaping material flowing from the material conveying mechanism  40  to the nozzle  60 , that is, a flow rate of the shaping material ejected from the nozzle  60 , by controlling a rotation angle of the butterfly valve using the valve drive unit  75 . The flow rate adjusting unit  70  can not only adjust the flow rate of the shaping material but also control on and off of an outflow of the shaping material. 
       FIG.  3    is a schematic perspective view showing a structure of the screw  41  at the groove forming surface  42  side. In  FIG.  3   , a position of the central axis RX of the screw  41  is indicated by a dashed line. As described above, the screw grooves  45  are provided on the groove forming surface  42 . A screw center portion  47  that is a center portion of the groove forming surface  42  of the screw  41  is formed as a recess to which one ends of the screw grooves  45  are coupled. The screw center portion  47  faces the communication hole  56  of the barrel  50 . The screw center portion  47  intersects the central axis RX. 
     The screw groove  45  of the screw  41  forms a so-called scroll groove. The screw groove  45  extends in a vortex shape from the screw center portion  47  toward an outer periphery of the screw  41  in a manner of drawing an arc. The screw groove  45  may be formed to extend in an involute curve shape or a spiral shape. The groove forming surface  42  is provided with ridge portions  46  that form side wall portions of the respective screw grooves  45  and extend along the respective screw grooves  45 . Each of the screw grooves  45  is continuous up to a material introduction port  44  formed on a side surface  43  of the screw  41 . The material introduction port  44  is a portion that receives a material supplied via the supply path  22  of the material storage unit  20 . 
       FIG.  3    shows an example of the screw  41  having three screw grooves  45  and three ridge portions  46 . The number of the screw grooves  45  and the number of the ridge portions  46  provided at the screw  41  are not limited to three. The screw  41  may be provided with only one screw groove  45 , or two or a plurality of screw grooves  45 .  FIG.  3    shows an example of the screw  41  in which the material introduction port  44  is formed at three positions. The number of the material introduction ports  44  provided in the screw  41  is not limited to three. The screw  41  may be provided with one material introduction port  44 , or two or a plurality of material introduction ports  44 . 
       FIG.  4    is a top view showing a configuration of the barrel  50  at the screw facing surface  52  side. As described above, the communication hole  56  is formed in the center of the screw facing surface  52 . A plurality of guide grooves  54  are formed around the communication hole  56  on the screw facing surface  52 . Each of the guide grooves  54  has one end coupled to the communication hole  56 . The guide grooves  54  extend in a vortex shape from the communication hole  56  toward an outer periphery of the screw facing surface  52 . Each of the guide grooves  54  has a function of guiding the shaping material to the communication hole  56 . One end of the guide groove  54  may not be coupled to the communication hole  56 . The guide grooves  54  may not be formed in the barrel  50 . 
       FIG.  5    is a diagram illustrating attachment of the nozzle  60  to and detachment of the nozzle  60  from the through hole  80 .  FIG.  5    shows the nozzle  60  in a state of being removed from the through hole  80 . In the present embodiment, a nozzle screw portion  67  is formed at a portion of the nozzle  60  to be coupled to the through hole  80 , and a through hole screw portion  81  to be screwed with the nozzle screw portion  67  is provided at a portion of the through hole  80  to be coupled to the nozzle  60 . The nozzle  60  is inserted into the through hole  80 , and is attached to the heating block  90  by screwing the nozzle screw portion  67  and the through hole screw portion  81  together. In addition, the nozzle  60  is removed from the heating block  90  by unscrewing the nozzle screw portion  67  and the through hole screw portion  81  and pulling out the nozzle  60  from the through hole  80 . In the present embodiment, the nozzle  60  is positioned at a lower portion of the barrel  50  and is attached to the heating block  90  so that the communication hole  56  and the nozzle flow path  61  communicate with each other. 
     The nozzle  60  has the shield  68 . The shield  68  prevents the heat of the heating block  90  from being transferred to the stacked material. Specifically, the shield  68  is formed as a portion having a larger area of a cross section along the X direction and the Y direction than other portions in the Z direction which is a direction along the nozzle flow path  61 . In an attached state, the shield  68  is positioned between the heating block  90  and the stacked material, thereby preventing heat transfer from the heating block  90  to the stacked material. 
     The shield  68  is generally formed of, for example, stainless steel or the like having a low emissivity. The shield  68  may be formed of, for example, a material other than stainless steel. For example, when the shield  68  is formed of aluminum or the like having a lower emissivity than stainless steel, an effect of preventing heat transfer to the stacked material due to heat radiation of the heating block  90  is further improved. For example, when the shield  68  is generally formed of polytetrafluoroethylene (PTFE) or the like having a low thermal conductivity, thermal conduction from the heating block  90  to the shield  68  is further prevented. The shield  68  may be formed integrally with the nozzle  60 , or may be formed separately from the nozzle  60 . Further, the shield  68  may be formed of a plurality of materials. 
     The nozzle  60  according to the present embodiment is provided with a memory  66  implemented by an IC chip serving as a storage medium. The memory  66  is positioned between the nozzle opening  63  and the shield  68  in the Z direction that is the direction along the nozzle flow path  61 . Accordingly, in an attached state, the shield  68  is positioned between the memory  66  and the heating block  90 . Therefore, heat transfer from the heating block  90  to the memory  66  is prevented by the shield  68  in a similar manner to the effect that the heat transfer from the heating block  90  to the stacked material is prevented by the shield  68 . 
     When the nozzle  60  is attached to the heating block  90 , the memory  66  is electrically coupled to the control unit  300  via a wire (not shown) and a coupling unit. The memory  66  functions as a nozzle information storage unit that stores nozzle information of the nozzle  60 . 
       FIG.  6    is a diagram showing an example of the nozzle information. In the present embodiment, nozzle identification information, material information, a cumulative ejection amount, a nozzle use time, and a cleaning processing execution history are stored in the memory  66  as the nozzle information. 
     The nozzle identification information is information for uniquely identifying the nozzle  60 . For example, the nozzle identification information is recorded at the time of manufacturing the nozzle  60 . 
     The material information is information on a type of the plasticizing material. More specifically, the material information is information indicating a type of the plasticizing material which is a raw material of the shaping material discharged from the nozzle  60 . The material information is recorded by the control unit  300 . More specifically, the control unit  300  receives an operation of designating a type of the plasticizing material from a user, and records the information indicating a type of the plasticizing material in the memory  66  as the material information. 
     The cumulative ejection amount is information indicating a total amount of the shaping material ejected from the nozzle  60 . In the present embodiment, the cumulative ejection amount includes an ejection amount of the shaping material ejected in a stacking processing executed during a three-dimensional shaping processing to be described later and an ejection amount of the shaping material discharged in a cleaning processing. The cumulative ejection amount is recorded by the control unit  300  in the three-dimensional shaping processing to be described later. In another embodiment, the ejection amount of the shaping material discharged in the cleaning processing may not be included in the cumulative ejection amount. In the present embodiment, the ejection amount is represented by a weight of the shaping material. In another embodiment, the ejection amount may be represented by a volume or a length of the shaping material. 
     The nozzle use time is a total time of a time during which a three-dimensional shaped object is shaped using the nozzle  60 . In the present embodiment, the nozzle use time includes a time during which the shaping material is ejected from the nozzle  60  in the stacking processing executed during the three-dimensional shaping processing to be described later and a time during which the shaping material is ejected from the nozzle  60  in the cleaning processing. The control unit  300  counts a use time of the nozzle  60 , and thus the nozzle use time is recorded by the control unit  300 . In another embodiment, the time during which the shaping material is ejected in the cleaning processing may not be included in the nozzle use time. 
     The cleaning processing execution history is information on an execution history of the cleaning processing. In the present embodiment, the cleaning processing execution history includes information indicating a cumulative ejection amount when the cleaning processing is executed. The cleaning processing execution history may include information on date and time when the cleaning processing is executed. The cleaning processing execution history is recorded by the control unit  300  in the three-dimensional shaping processing to be described later. 
     The control unit  300  reads the nozzle information from the memory  66 , and determines a mode of a cleaning operation or an execution timing of the cleaning processing based on at least one of the material information, the cumulative ejection amount, and the nozzle use time. In the present embodiment, the control unit  300  determines a mode of the cleaning operation based on the material information and the cumulative ejection amount. 
     The control unit  300  can acquire the nozzle information from the memory  66  provided in the nozzle  60  and display each piece of information included in the nozzle information on the display device  400 . In this manner, identification information of the nozzle  60  that is currently attached to the three-dimensional shaping device  10 , a type of the shaping material ejected from the nozzle  60 , the cumulative ejection amount, the nozzle use time, and the cleaning processing execution history can be presented to a user. 
       FIG.  7    is a diagram illustrating a schematic configuration of the cleaning mechanism  250 . As described above, the cleaning mechanism  250  includes the brush  251  and the blade  252 . The brush  251  is formed by arranging a plurality of hair bundles along the Y direction. The blade  252  is a plate-shaped member extending along the Z direction and the Y direction. A tip end of the brush  251  and a tip end of the blade  252  are directed in the +Z direction. The tip end of the blade  252  is disposed lower than the tip end of the brush  251 . As described above, the brush  251  and the blade  252  are disposed at a height at which the brush  251  and the blade  252  can come into contact with the nozzle  60 . In addition, the tip end of the brush  251  is disposed at a height at which the tip end of the brush  251  can come into contact with the shield  68  provided at the nozzle  60 , and the tip end of the blade  252  is disposed at a height at which the tip end of the blade  252  does not come into contact with the shield  68 . In the present embodiment, the brush  251  and the blade  252  are integrated by a fixture  258 , and can be replaced at the same time when the brush  251  and the blade  252  are consumed. The brush  251  and the blade  252  may be individually replaced. 
     The brush  251  and the blade  252  each have a melting point higher than a plasticizing temperature of the plasticizing material plasticized in the ejection unit  100 . The brush  251  and the blade  252  each have hardness lower than the hardness of the nozzle  60 . In the present embodiment, the hardness refers to Vickers hardness. Further, in the present embodiment, an elastic modulus of the blade  252  is higher than an elastic modulus of the brush  251 . In the present embodiment, the elastic modulus refers to a Young&#39;s modulus. The nozzle  60  is formed of, for example, a metal such as cemented carbide, tool steel, and SUS, and the brush  251  and the blade  252  are formed of, for example, a metal such as SUS, iron, or brass. The brush  251  and the blade  252  may be made of resin. The brush  251  may be formed of natural fiber or chemical fiber, and the blade  252  may be formed of ceramic. In another embodiment, the elastic modulus of the blade  252  and the elastic modulus of the brush  251  may be the same, or the elastic modulus of the brush  251  may be higher than the elastic modulus of the blade  252 . 
     The cleaning mechanism  250  further includes a purge unit  253 . The purge unit  253  is also referred to as a purge ledge. In the present embodiment, the purge unit  253 , the blade  252 , and the brush  251  are arranged in this order along the +X direction. That is, the blade  252  is disposed between the purge unit  253  and the brush  251 . A tip end of the purge unit  253  in the +Z direction is lower than the tip end of the blade  252 . In the cleaning processing to be described later, a waste material ejected from the nozzle  60  falls onto the purge unit  253 , is collected in a spherical shape on the purge unit  253 , and falls into the purge waste container  260 . An upper surface of the purge unit  253  is formed as an inclined surface in order to promote the waste material to fall down. More specifically, the purge unit  253  includes a first inclined surface  254 , a second inclined surface  255 , and a third inclined surface  256  in an order from the farthest one from the blade  252  and in an order from the lowest position in the vertical direction. The first inclined surface  254 , the second inclined surface  255 , and the third inclined surface  256  are each inclined such that a position of an end portion in the +X direction is higher than a position of an end portion in the −X direction. In the present embodiment, inclination angles of the second inclined surface  255  and the third inclined surface  256  relative to a horizontal plane is larger than an inclination angle of the first inclined surface  254  relative to the horizontal plane. 
       FIG.  8    is a flowchart showing a three-dimensional shaping processing representing a method for manufacturing a three-dimensional shaped object. The three-dimensional shaping processing is executed when the control unit  300  of the three-dimensional shaping device  10  receives a predetermined operation for shaping a three-dimensional shaped object from a user. 
     In step S 100 , the control unit  300  acquires shaping data from an external computer, a recording medium, or the like. The shaping data includes shaping path data indicating a movement path of the nozzle  60  for each layer for forming a three-dimensional shaped object. The shaping path data is associated with ejection amount data indicating an ejection amount of a material to be ejected from the nozzle  60 . 
     In step S 110 , the control unit  300  acquires the nozzle information from the memory  66  of the nozzle  60 , and stores the nozzle information in the storage unit  320 . 
     In step S 120 , the control unit  300  starts to execute a stacking processing. The stacking processing is a processing of shaping a three-dimensional shaped object including a plurality of layers by controlling the drive unit  210  and the ejection unit  100  in accordance with the shaping data and ejecting a shaping material from the ejection unit  100  onto the stage  220  for each layer. In the stacking processing, the control unit  300  updates a cumulative ejection amount by sequentially adding an ejection amount of the shaping material ejected from the nozzle  60  to a cumulative ejection amount stored in the storage unit  320 . Step S 120  is also referred to as a stacking step. 
     During the execution of the stacking processing, in step S 130 , the control unit  300  determines whether to execute a cleaning processing. For example, the control unit  300  determines to execute the cleaning processing when an ejection abnormality of the shaping material is detected in the plasticizing mechanism  30 , when a predetermined number of layers are formed, when a type of the shaping material is changed, when a command for instructing cleaning included in the shaping data is received, or the like. In the present embodiment, the control unit  300  determines to execute the cleaning processing when a predetermined number of layers are formed. 
     When it is determined in step S 130  that the cleaning processing is to be executed, in step S 140 , the control unit  300  determines a mode of a cleaning operation to be executed in the cleaning processing to be described later based on the nozzle information acquired from the memory  66  and a cleaning condition table stored in the storage unit  320 . 
       FIG.  9    is a diagram showing an example of a cleaning condition table TB 1 . In the cleaning condition table TB 1  according to the present embodiment, a cumulative ejection amount, the number of brushing times, and a discharge amount are associated with a type of a plasticizing material specified by the material information. The number of brushing times is determined to increase as the cumulative ejection amount increases. The discharge amount is determined to increase as the cumulative ejection amount increases. The number of brushing times is the number of times at which the nozzle  60  reciprocates on the brush  251  and the blade  252  of the cleaning mechanism  250 . The discharge amount is an amount at which the shaping material is discharged as a waste material from the nozzle  60  onto the purge unit  253 . In step S 140 , the control unit  300  specifies the number of brushing times and the discharge amount corresponding to the material type included in the nozzle information acquired from the memory  66  of the nozzle  60  in step S 110  and the sequentially calculated cumulative ejection amount. A combination of the number of brushing times and the discharge amount specified in this manner represents a mode of a cleaning operation in the present embodiment. 
     In step S 150 , the control unit  300  executes the cleaning processing in accordance with the mode of the cleaning operation determined in step S 140 . In the cleaning processing, first, the control unit  300  moves the nozzle  60  onto the purge unit  253 , and discharges the shaping material as a waste material according to the discharge amount determined in step S 140 . The control unit  300  adds an amount of the discharged shaping material to the cumulative ejection amount. Thereafter, the nozzle  60  reciprocates on the blade  252  and the brush  251  in accordance with the number of brushing times in the cleaning operation determined in step S 140 . A cleaning strength increases as the number of brushing times increases, and the cleaning strength increases as the discharge amount increases. Step S 150  is also referred to as a cleaning step. In another embodiment, the discharge of the waste material from the nozzle  60  may be omitted in the cleaning processing. In this case, the discharge amount may not be defined in the cleaning condition table TB 1  shown in  FIG.  9   . 
       FIG.  10    is a diagram illustrating a reciprocating operation of the nozzle  60  according to the present embodiment.  FIG.  10    shows the tip end of the nozzle  60  and the brush  251  and the blade  252  of the cleaning mechanism  250  as viewed from above, and a trajectory along which the nozzle  60  moves is indicated by a broken line. As shown in  FIG.  10   , the cleaning mechanism  250  has a longitudinal direction. In the present embodiment, the longitudinal direction is the Y direction. In the present embodiment, the control unit  300  brings the tip end of the nozzle  60  into contact with the blade  252 , and then brings the tip end of the nozzle  60  into contact with the brush  251  in the cleaning operation. Thereafter, the control unit  300  causes the nozzle  60  to reciprocate in a manner in which the nozzle  60  crosses the brush  251  and the blade  252  by the number of brushing times specified in step S 140 . At this time, the control unit  300  causes the nozzle  60  to reciprocate along an M-shaped or W-shaped trajectory, in other words, along a trajectory indicating a triangular wave shape in the longitudinal direction of the cleaning mechanism  250  from a contact start position at which the nozzle  60  and the cleaning mechanism  250  first come into contact with each other. Accordingly, in the cleaning operation, the control unit  300  can cause the nozzle  60  to reciprocate in the X direction such that the nozzle  60  comes into contact with the brush  251  or the blade  252  at different positions each time the nozzle  60  passes through the brush  251  or the blade  252 .  FIG.  10    shows a reciprocating operation in a case where the number of brushing times is three. Although the control unit  300  brings the nozzle  60  into contact with both the brush  251  and the blade  252  in the cleaning operation according to the present embodiment, the control unit  300  may bring the nozzle  60  into contact with either one of the brush  251  and the blade  252 . 
     When the cleaning processing is executed, in step S 160  shown in  FIG.  8   , the control unit  300  records a cleaning processing execution history and the cumulative ejection amount in association with each other in the memory  66  provided in the nozzle  60 . More specifically, in the present embodiment, the control unit  300  records a cumulative ejection amount at a time point when a finally executed cleaning processing is completed as the cleaning processing execution history. In another embodiment, in addition to the cumulative ejection amount or instead of the cumulative ejection amount, a nozzle use time may be recorded in association with the cleaning processing execution history. 
     After the cleaning processing execution history is recorded in step S 160 , or after it is determined in step S 130  that the cleaning processing is not to be executed, in step S 170 , the control unit  300  determines whether the stacking processing is completed for all layers, that is, whether shaping of the three-dimensional shaped object is completed. When the stacking processing is not completed, the control unit  300  returns the processing to step S 120  and continues the stacking processing. When the stacking processing is completed, in step S 180 , the control unit  300  records the cumulative ejection amount sequentially integrated in the stacking processing and the cleaning processing in the memory  66  provided in the nozzle  60 . 
     According to the three-dimensional shaping device  10  of the present embodiment described above, since the control unit  300  records the identification information of the nozzle  60 , the material information on the type of the plasticizing material, and the cumulative ejection amount of the shaping material in association with one another, it is possible to manage the use of the nozzle  60  so as to avoid unexpected nozzle clogging. Particularly, in the present embodiment, since the nozzle information is recorded in the memory  66  provided in the nozzle  60 , even when the nozzle  60  is replaced, it is possible to execute the cleaning processing suitable for the nozzle  60  using the material information or the cumulative ejection amount recorded in the memory  66  of the replaced nozzle  60 . 
     In the present embodiment, the nozzle  60  reciprocates such that the nozzle  60  comes into contact with the brush  251  or the blade  252  at different positions in the cleaning operation. Therefore, it is possible to prevent a waste material adhering to the cleaning mechanism  250  from re-adhering to the nozzle  60  during the cleaning processing. 
     In the present embodiment, the mode of the cleaning operation is determined based on the material information and the cumulative ejection amount included in the nozzle information. Therefore, for example, even when a state of deterioration or contamination of the nozzle  60  corresponding to the cumulative ejection amount differs in accordance with a material, it is possible to execute a cleaning operation suitable for the material. 
     In the present embodiment, the number of brushing times and the discharge amount increase as the cumulative ejection amount increases, so that the cleaning strength increases. The larger the cumulative ejection amount is, the more the deterioration or contamination of the nozzle progresses. Therefore, it is possible to prevent unexpected nozzle clogging of the nozzle and improve shaping quality by increasing the cleaning strength as the cumulative ejection amount increases. 
     In the present embodiment, the elastic modulus of the blade  252  provided in the cleaning mechanism  250  is higher than the elastic modulus of the brush  251 . Therefore, it is easy to remove a material adhering to the nozzle  60  by the blade  252 . 
     In the present embodiment, since the tip end of the blade  252  is disposed lower than the tip end of the brush  251  in the cleaning mechanism  250 , a material adhering to the tip end of the nozzle  60  can be efficiently removed by the blade  252 . 
     In the present embodiment, since the tip end of the brush  251  is disposed at a height at which the tip end can come into contact with the shield  68  and the tip end of the blade  252  is disposed at a height at which the tip end does not contact the shield  68 , it is possible to remove a material adhering to the shield  68  by the brush  251 . 
     In the present embodiment, the control unit  300  brings the tip end of the nozzle  60  into contact with the blade  252 , removes the shaping material adhering to the tip end of the nozzle  60 , and then brings the tip end of the nozzle  60  into contact with the brush  251  in the cleaning operation, so that the nozzle  60  can be efficiently cleaned. 
     In the present embodiment, the control unit  300  ejects a waste material from the nozzle  60  onto the purge unit  253  and then moves the nozzle  60  toward the brush  251  and the blade  252  in the cleaning processing, so that the nozzle  60  can be cleaned after the shaping material remaining in the nozzle flow path  61  is removed. 
     Although the stacking processing and the cleaning processing are repeatedly executed during the shaping of the three-dimensional shaped object in the present embodiment, the cleaning processing may be executed not only during the shaping but also before the shaping of the three-dimensional shaped object is started or after the shaping of the three-dimensional shaped object is completed. 
       FIGS.  11  to  14    are diagrams illustrating other examples of the reciprocating operation of the nozzle  60  in the cleaning processing.  FIG.  11    shows an example in which the nozzle  60  is moved along a trajectory indicating a rectangular wave shape in the longitudinal direction of the cleaning mechanism  250 .  FIG.  12    shows an example in which the nozzle  60  is moved along a trajectory indicating a sine wave shape in the longitudinal direction of the cleaning mechanism  250 .  FIG.  13    shows an example in which the nozzle  60  is moved along a trajectory indicating a sawtooth wave shape in the longitudinal direction of the cleaning mechanism  250 . As shown in these drawings, the control unit  300  can cause the nozzle  60  to reciprocate in various trajectories in the cleaning operation. As shown in  FIG.  14   , in the cleaning operation, the control unit  300  may set the number of times at which the nozzle  60  crosses the brush  251  to be larger than the number of times at which the nozzle  60  crosses the blade  252 . In this manner, wearing of the blade  252  can be prevented. 
     In step S 140  of the three-dimensional shaping processing shown in  FIG.  8   , the control unit  300  may determine a trajectory of the reciprocating operation of the nozzle  60  as shown in  FIGS.  10  to  14    as the mode of the cleaning operation, in addition to or instead of the number of brushing times and the discharge amount. In this case, a trajectory of the reciprocating operation of the nozzle  60  corresponding to a cumulative ejection amount is defined in the cleaning condition table TB 1  shown in  FIG.  9   . In this manner, the control unit  300  can determine the trajectory of the reciprocating operation of the nozzle  60  in accordance with the cumulative ejection amount. 
     B. Second Embodiment 
     In the first embodiment described above, the control unit  300  determines the mode of the cleaning operation based on the material information and the cumulative ejection amount included in the nozzle information shown in  FIG.  6   . On the other hand, in a second embodiment, the control unit  300  determines an execution timing of the cleaning processing based on the material information and the cumulative ejection amount. The configuration of the three-dimensional shaping device  10  according to the second embodiment is the same as the configuration of the three-dimensional shaping device  10  according to the first embodiment. 
       FIG.  15    is a flowchart showing a three-dimensional shaping processing according to the second embodiment. In the three-dimensional shaping processing according to the second embodiment, the control unit  300  acquires the shaping data in step S 200 , and then acquires the nozzle information from the memory  66  of the nozzle  60  in step S 210 . Then, in step S 220 , the stacking processing is started. In the stacking processing, the control unit  300  updates a cumulative ejection amount by sequentially adding an ejection amount of the shaping material ejected from the nozzle  60  to a cumulative ejection amount acquired from the memory  66  of the nozzle  60  in step S 210 , and stores the cumulative ejection amount in the storage unit  320 . Further, in the stacking processing, the control unit  300  according to the present embodiment sequentially adds an ejection amount from a previous cleaning processing up to a current ejection amount. This ejection amount is referred to as an inter-cleaning ejection amount. 
     During the execution of the stacking processing, in step S 230 , the control unit  300  determines an execution timing of the cleaning processing based on the nozzle information acquired from the memory  66  and a cleaning condition table stored in the storage unit  320 . 
       FIG.  16    is a diagram showing an example of a cleaning condition table TB 2 . In the cleaning condition table TB 2  according to the second embodiment, a cumulative ejection amount and a cleaning frequency are associated with a type of a plasticizing material specified by the material information. The cleaning frequency is set to increase as the cumulative ejection amount increases. In the example shown in  FIG.  16   , for example, for a material A, when the cumulative ejection amount is up to 1000 g, the cleaning processing is executed every time 50 g of the shaping material is ejected, and when the cumulative ejection amount is 1000 g to 5000 g, the cleaning processing is executed every time 40 g of the shaping material is ejected. The cleaning frequency specified in this manner represents the execution timing of the cleaning processing. 
     In step S 240 , the control unit  300  determines whether a current timing is the execution timing of the cleaning processing determined in step S 230  using the inter-cleaning ejection amount described above. For example, in a case where the shaping material is the material A and the cumulative ejection amount is up to 1000 g, when the inter-cleaning ejection amount is 50 g or more, it is determined that the current timing is the execution timing of the cleaning processing. 
     When it is determined that the current timing is the execution timing of the cleaning processing, the control unit  300  executes the cleaning processing in step S 250 . In the cleaning processing executed in the second embodiment, for example, the cleaning operation determined according to the nozzle information may be performed as described in the first embodiment. In addition, the cleaning operation may be performed in accordance with a predetermined number of brushing times, a discharge amount, and a movement trajectory of the nozzle. When the cleaning processing is completed, the control unit  300  resets the inter-cleaning ejection amount to zero. Then, in step S 260 , a cleaning execution history is recorded in the memory  66  provided in the nozzle  60 . 
     After the cleaning execution history is recorded in step S 260 , or after it is determined in step S 240  that the current timing is not the execution timing of the cleaning processing, the control unit  300  determines in step S 270  whether the stacking processing is completed for all layers, that is, whether the shaping of the three-dimensional shaped object is completed. When the stacking processing is not completed, the control unit  300  returns the processing to step S 220  and continues the stacking processing. When the stacking processing is completed, in step S 280 , the control unit  300  records the cumulative ejection amount sequentially integrated in the stacking processing and the cleaning processing in the memory  66  provided in the nozzle  60 . 
     According to the three-dimensional shaping device  10  of the second embodiment described above, it is possible to manage the use of the nozzle  60  so as to avoid unexpected nozzle clogging, and it is possible to prevent a waste material adhering to the cleaning mechanism  250  from re-adhering to the nozzle  60  in a similar manner to the first embodiment. 
     In the present embodiment, the execution timing of the cleaning processing is determined based on the material information and the cumulative ejection amount included in the nozzle information. Therefore, for example, even when a state of deterioration or contamination of the nozzle  60  corresponding to the cumulative ejection amount differs in accordance with a material, it is possible to execute a cleaning processing at a timing suitable for the material. 
     In the present embodiment, the cleaning frequency increases as the cumulative ejection amount increases. The larger the cumulative ejection amount is, the more the deterioration or contamination of the nozzle progresses. Therefore, it is possible to prevent unexpected nozzle clogging of the nozzle and improve shaping quality by increasing the cleaning frequency as the cumulative ejection amount increases. 
     C. Third Embodiment 
     In the second embodiment described above, the cleaning frequency is determined in accordance with the material information and the cumulative ejection amount. On the other hand, in a third embodiment, the cleaning frequency is determined in accordance with the material information and the number of cleaning times. The configuration of the three-dimensional shaping device  10  according to the third embodiment is the same as the configuration of the three-dimensional shaping device  10  according to the first embodiment. 
       FIG.  17    is a diagram showing a correspondence relationship between the number of cleaning times and a cleaning interval. In the third embodiment, the same processing as the three-dimensional shaping processing according to the second embodiment shown in  FIG.  15    is executed. In step S 230  shown in  FIG.  15   , the control unit  300  determines the execution timing of the cleaning processing according to the correspondence relationship between the number of cleaning times and the cleaning interval as shown in  FIG.  17   , which is determined according to the material information. According to the correspondence relationship shown in  FIG.  17   , as the number of cleaning times increases to n−1 times, n times, and n+1 times, n being an integer of 2 or more, the cleaning interval decreases. That is, in the present embodiment, when the control unit  300  determines the execution timing of the cleaning processing for a plurality of times, the control unit  300  determines the cleaning interval such that an interval from the execution timing of an n-th cleaning processing to the execution timing of an (n+1)-th cleaning processing is shorter than an interval from the execution timing of an (n−1)-th cleaning processing to the execution timing of the n-th cleaning processing. 
     According to the third embodiment described above, as the number of execution times of the cleaning processing increases, the cleaning processing is executed at a shorter interval. Therefore, it is possible to prevent frequent occurrence of nozzle clogging due to the progress of deterioration or contamination of the nozzle  60 , and it is possible to improve shaping quality. 
     D. Fourth Embodiment 
     In the first embodiment described above, the mode of the cleaning operation is determined according to the material information and the cumulative ejection amount. On the other hand, in a fourth embodiment, the mode of the cleaning operation is determined according to the material information and the number of cleaning times. The configuration of the three-dimensional shaping device  10  according to the fourth embodiment is the same as the configuration of the three-dimensional shaping device  10  according to the first embodiment. 
       FIG.  18    is a diagram showing a correspondence relationship between the number of cleaning times and a cleaning strength. In the fourth embodiment, the same processing as the three-dimensional shaping processing according to the first embodiment shown in  FIG.  8    is executed. In step S 140  shown in  FIG.  8   , the control unit  300  determines the mode of the cleaning operation according to the correspondence relationship between the number of cleaning times and the cleaning strength as shown in  FIG.  18   , which is determined according to the material information. According to the correspondence relationship shown in  FIG.  18   , as the number of cleaning times increases to m−1 times, m times, and m+1 times, m being an integer of 2 or more, the cleaning strength increases. That is, in the present embodiment, when the control unit  300  determines the execution timing of the cleaning processing for a plurality of times, the control unit  300  determines the cleaning strength such that a cleaning strength in an (m+1)-th cleaning processing is stronger than a cleaning strength in an m-th cleaning processing. In the present embodiment, the cleaning strength represents one of the number of brushing times and the discharge amount. For example, as the cleaning strength increases, the number of brushing times increases. As the cleaning strength increases, the discharge amount increases. 
     According to the fourth embodiment described above, as the number of execution times of the cleaning processing increases, the cleaning strength increases. Therefore, it is possible to prevent frequent occurrence of nozzle clogging due to the progress of deterioration or contamination of the nozzle  60 , and it is possible to improve shaping quality. 
     The number of cleaning times in the third embodiment and the fourth embodiment described above may be the number of cleaning times in one three-dimensional shaping processing, or may be a cumulative number of cleaning times. When the number of cleaning times is the cumulative number of cleaning times, the number of cleaning times is recorded as nozzle information in the memory  66  provided in the nozzle  60 . In this manner, it is possible to manage the cumulative number of cleaning times for each nozzle  60 . 
     E. Fifth Embodiment 
     In the second embodiment described above, the cleaning processing of the nozzle  60  is executed at a cleaning timing corresponding to the cleaning frequency determined according to the material information and the cumulative ejection amount. On the other hand, in a fifth embodiment, a processing of changing a cleaning timing once determined is executed. 
       FIG.  19    is a flowchart showing a timing change processing executed in the fifth embodiment. The timing change processing is simultaneously executed in parallel by the control unit  300  while the three-dimensional shaping processing in the second embodiment shown in  FIG.  15    is executed. 
     In step S 300 , the control unit  300  determines whether a forced cleaning processing is executed. In the present embodiment, it is assumed that the cleaning processing is forcibly executed when the plasticizing material is changed. In the forced cleaning processing, the shaping material remaining in the plasticizing mechanism  30  is discharged as a waste material, and a reciprocating operation of the nozzle  60  for removing the shaping material adhering to the nozzle  60  is performed. 
     When it is determined that the forced cleaning processing is executed, the control unit  300  changes the execution timing of the cleaning processing in step S 310 . Specifically, the inter-cleaning ejection amount used to determine whether it is the execution timing of the cleaning processing in step S 240  shown in  FIG.  15    is reset to zero. For example, when the inter-cleaning ejection amount is calculated to be 30 g in the stacking processing so far, a value of the inter-cleaning ejection amount is set to zero. Then, in step S 320 , the control unit  300  records a type of the changed plasticizing material in the memory  66  provided in the nozzle  60 , and updates the nozzle information in the memory  66 . When it is determined in step S 300  that the shaping material is not changed, the control unit  300  skips the processings in step S 310  and step S 320  described above. 
     According to the fifth embodiment described above, when the plasticizing material is changed and the forced cleaning processing is executed, the execution timing of the cleaning processing is changed. Accordingly, when a period from an execution timing of a p-th cleaning processing to an execution timing of a (p+1)-th cleaning processing is shorter than a period determined based on the cumulative ejection amount, p being an integer of 1 or more, the control unit  300  can change and delay a start timing of the (p+1)-th cleaning processing. Therefore, it is possible to prevent a subsequent cleaning processing from being executed immediately after the forced cleaning processing, and it is possible to prevent the cleaning processing from being executed excessively. 
     The forced cleaning processing is not limited to being executed when the plasticizing material is changed. For example, the forced cleaning processing may be executed when a user manually instructs to execute the cleaning processing at any timing. 
     In the present embodiment, an execution timing of a cleaning processing to be executed next time is changed by resetting the inter-cleaning ejection amount to zero. On the other hand, for example, in step S 310 , the control unit  300  may determine to cancel the cleaning processing to be executed next time, that is, not to execute the (p+1)-th cleaning processing. In this manner, it is also possible to prevent the cleaning processing from being executed excessively. 
     In the fifth embodiment, when it is determined in step S 300  shown in  FIG.  19    that the forced cleaning processing is executed, the control unit  300  changes the execution timing of the cleaning processing. On the other hand, in another embodiment, for example, when it is determined in step S 300  that the forced cleaning processing is executed, the control unit  300  may change the mode of the cleaning operation such as the number of brushing times and the discharge amount in step S 310 . 
     F. Sixth Embodiment 
       FIG.  20    is a flowchart showing a cleaning condition change processing executed by the control unit  300  according to a sixth embodiment. The cleaning condition change processing is executed before the execution of the cleaning processing in step S 150  in the three-dimensional shaping processing according to the first embodiment shown in  FIG.  8    or the cleaning processing in step S 250  in the three-dimensional shaping processing according to the second embodiment shown in  FIG.  15   . 
     In step S 400 , the control unit  300  inspects a state of the nozzle  60 . For example, the control unit  300  causes a camera provided in the three-dimensional shaping device  10  to capture an image of the nozzle  60 , and inspects whether a material adheres to the nozzle  60  based on the captured image. For example, the control unit  300  may inspect whether ejection from the nozzle  60  is normally performed by measuring whether a specified amount of the shaping material is ejected using a weight sensor or the like. 
     In step S 410 , the control unit  300  determines whether a current cleaning processing is necessary according to an inspection result of the nozzle  60  in step S 400 . In a case where an amount of the shaping material adhering to the nozzle  60  is smaller than a predetermined amount or in a case where a predetermined amount or more of the shaping material is ejected from the nozzle  60 , the control unit  300  determines that the cleaning processing is not necessary, and in step S 420 , the control unit  300  cancels the cleaning processing scheduled to be executed immediately after the execution of the cleaning condition change processing. 
     After the cleaning processing is cancelled, the control unit  300  changes a cleaning condition in step S 430 . Specifically, for example, a value of the cumulative ejection amount in the cleaning condition table TB 1  shown in  FIG.  9    used in the first embodiment is updated and increased to change a cleaning condition in a manner in which the number of brushing times or the discharge amount is increased slowly. For example, the value of the cumulative ejection amount or the cleaning frequency in the cleaning condition table TB 2  shown in  FIG.  16    used in the second embodiment is updated and increased to change a cleaning condition in a manner in which a cleaning interval is increased. 
     When it is determined in step S 410  that the cleaning processing is necessary, the control unit  300  skips the processings in step S 420  and step S 430 . 
     When the cleaning condition change processing described above ends, the cleaning processing and the stacking processing are continued in accordance with the three-dimensional shaping processing in the first embodiment or the second embodiment. 
     According to the sixth embodiment described above, it is possible to cancel the cleaning processing according to the inspection result of the nozzle  60 . Accordingly, when the cleaning processing is executed in accordance with an execution timing of an r-th cleaning processing that has been already determined, r being an integer of 1 or more, the state of the nozzle  60  is inspected before the execution of the cleaning processing, and the mode of cleaning operations of the r-th cleaning processing and subsequent cleaning processings or the execution timing of the cleaning processing can be changed based on the inspection result. Therefore, it is possible to prevent the cleaning from being performed in a situation in which the cleaning processing of the nozzle  60  is not necessary, and thus it is possible to prevent the cleaning processing from being executed excessively. 
     Although the control unit  300  updates the value in the cleaning condition table in step S 430  shown in  FIG.  20    in the present embodiment, this processing may be omitted. That is, the control unit  300  may only cancel the cleaning processing scheduled to be executed immediately thereafter. 
     G. Seventh Embodiment 
       FIG.  21    is a flowchart showing a nozzle information update processing executed by the control unit  300  according to a seventh embodiment. The nozzle information update processing is executed before the execution of the three-dimensional shaping processing according to the first embodiment or the three-dimensional shaping processing according to the second embodiment described above. 
     In step S 500 , the control unit  300  determines whether the plasticizing material is changed. For example, the control unit  300  determines that the plasticizing material is changed when a predetermined operation for changing the plasticizing material is received from a user. 
     When it is determined in step S 500  that the plasticizing material is changed, the control unit  300  updates the nozzle information in step S 510 . Specifically, the material information recorded in the memory  66  of the nozzle  60  is rewritten to information indicating the changed plasticized material. Further, a value of the cumulative ejection amount recorded in the memory  66  and the storage unit  320  is converted into a value corresponding to the changed plasticizing material and is rewritten. For example, in a case where the plasticizing material is changed from a material A to a material B, when the material B is a material for which the deterioration of the nozzle  60  progresses twice of the material A, the cumulative ejection amount recorded in the memory  66  so far is rewritten to a value of ½ of the value before the update. 
     When it is determined in step S 500  that the plasticizing material is not changed, the control unit  300  skips the processing in step S 510 . 
     According to the seventh embodiment described above, since the nozzle information is updated when the plasticizing material is changed, the mode of the cleaning operation and the execution timing of the cleaning processing can be determined according to the updated nozzle information in the three-dimensional shaping processing according to the first embodiment or the three-dimensional shaping processing according to the second embodiment. Therefore, even when the plasticizing material is changed, the cleaning processing can be executed using a cleaning operation or at an execution timing suitable for the changed plasticizing material. 
     Although the value of the cumulative ejection amount recorded in the memory  66  and the storage unit  320  is rewritten to a value corresponding to the changed plasticizing material when the nozzle information is updated in the present embodiment, this processing may be omitted. For example, a history of the plasticizing material ejected from the nozzle  60  so far may be recorded in the memory  66  of the nozzle  60  in association with the cleaning processing execution history. The control unit  300  may convert the cumulative ejection amount according to the history, and determine the mode of the cleaning operation and the execution timing of the cleaning processing based on the converted value. 
     H. Eighth Embodiment 
       FIG.  22    is a diagram showing a schematic configuration of a three-dimensional shaping device  12  according to an eighth embodiment. In the eighth embodiment, the three-dimensional shaping device  12  includes two ejection units and two cleaning mechanisms. Specifically, the ejection unit in the present embodiment includes a first ejection unit  101  provided with a first nozzle  71  that ejects a first shaping material, and a second ejection unit  102  provided with a second nozzle  72  that ejects a second shaping material. Each of the first nozzle  71  and the second nozzle  72  is provided with a memory, and the nozzle information shown in  FIG.  6    is recorded for each nozzle. The first shaping material and the second shaping material may be, for example, a combination of a shaping material and a support material, and may also be, for example, a combination of materials of different colors or a combination of different materials. The configurations of the first ejection unit  101  and the second ejection unit  102  are the same as the configuration of the ejection unit  100  according to the first embodiment. 
     The cleaning mechanism in the present embodiment includes a first cleaning mechanism  261  provided with a brush and a blade for cleaning the first nozzle  71 , and a second cleaning mechanism  262  provided with a brush and a blade for cleaning the second nozzle  72 . The configurations of the first cleaning mechanism  261  and the second cleaning mechanism  262  are the same as the configuration of the cleaning mechanism  250  according to the first embodiment. In the present embodiment, the two cleaning mechanisms  261  and  262  are arranged at a predetermined interval in the X direction, and a purge unit, the blade, and the brush provided in each of the cleaning mechanisms  261  and  262  are arranged in this order in the −Y direction. In the present embodiment, a longitudinal direction of the first cleaning mechanism  261  and the second cleaning mechanism  262  is the X direction. 
     In the present embodiment, the control unit  300  executes the three-dimensional shaping processing according to any one of the above-described embodiments by using the two ejection units  101  and  102  and the two cleaning mechanisms  261  and  262 . In the three-dimensional shaping processing according to the present embodiment, the stacking processing is executed by using the two ejection units  101  and  102 . In the cleaning processing, the control unit  300  performs the cleaning operation as shown in  FIG.  10    on the first nozzle  71  provided in the first ejection unit  101  and the second nozzle  72  provided in the second ejection unit  102 , thereby cleaning the first nozzle  71  and the second nozzle  72  using the first cleaning mechanism  261  and the second cleaning mechanism  262 . 
     According to the eighth embodiment described above, since the memory is provided in each of the nozzles  71  and  72  provided in the two ejection units  101  and  102 , it is possible to manage the nozzle information for each nozzle. As a result, the cleaning processing can be executed in a mode of a cleaning operation or at an execution timing corresponding to materials in the two nozzles  71  and  72 . Although an example in which the three-dimensional shaping device  12  includes two ejection units is described in the present embodiment, the three-dimensional shaping device  12  may include three or more ejection units. In addition, one cleaning mechanism may be used in common for a plurality of ejection units. 
     I. Ninth Embodiment 
       FIG.  23    is a diagram showing a schematic configuration of a three-dimensional shaping device  13  according to a ninth embodiment. The three-dimensional shaping device  13  according to the ninth embodiment is different from the three-dimensional shaping processing according to the first embodiment mainly in the configuration of the ejection unit, and the other configurations and processing contents of the three-dimensional shaping processing are the same as those according to the first to seventh embodiments. Therefore, the configuration of the ejection unit will be mainly described below. 
     The three-dimensional shaping device  13  according to the present embodiment includes an ejection unit  103 , a material storage unit  23 , the housing  110 , the drive unit  210 , the stage  220 , and the control unit  300 . The three-dimensional shaping device  13  further includes a blower  16 . The blower  16  is a blower that blows air toward the ejection unit  103  through a manifold  17 . In the present embodiment, a portion of the manifold  17 , the ejection unit  103 , the drive unit  210 , and the stage  220  are accommodated in the shaping space  111  in the housing  110 . 
     The material storage unit  23  according to the present embodiment is implemented as a holder that stores a filament-like material. The material storage unit  23  can wind out a material stored in the material storage unit  23  to the outside. 
       FIG.  24    is a diagram showing a schematic configuration of the ejection unit  103  according to the present embodiment. The ejection unit  103  includes a heating block  190  serving as a plasticizing mechanism that has a heater and is provided with a through hole  180 , a nozzle  73  detachably attached to the through hole  180 , and a material conveying mechanism  140  that conveys a material MF toward a nozzle flow path  74  of the nozzle  73  attached to the heating block  190 . The ejection unit  103  further includes a shield  92  that is disposed between the material conveying mechanism  140  and the heating block  190  in the Z direction and prevents heat transfer from the heating block  190  to the material conveying mechanism  140 . Different from the first embodiment, the material conveying mechanism  140  according to the present embodiment does not include the screw case  31  and the screw  41  and includes two wheels  49 . Different from the first embodiment, the heating block  190  does not include the barrel  50  and the case portion  91 . 
     The nozzle  73  according to the present embodiment is attached to the heating block  190  by being inserted into the through hole  180  and a shield opening  93  provided in the shield  92  from the −Z direction. In the present embodiment, a dimension of the nozzle  73  along the Z direction and a dimension of the nozzle flow path  74  along the Z direction are longer than a dimension of the through hole  180  along the Z direction. In the present embodiment, an inflow port  165  provided at a rear end of the nozzle  73  is located at the +Z direction side of the heating block  190 , more specifically, at the +Z direction side of the shield  92 . 
     Similar to the first embodiment, the nozzle  73  includes the shield  92 . Similar to the first embodiment, the nozzle  73  includes the memory  66 . Similar to the first embodiment, the memory  66  functions as a nozzle information storage unit, and stores the nozzle information. Similar to the first embodiment, the memory  66  is located between a nozzle opening  63 C and a shield  68 C in the Z direction. 
     The two wheels  49  constituting the material conveying mechanism  140  draws out the material MF in the material storage unit  23  to the outside, guides the material MF toward a space between the two wheels  49  by the rotation, and conveys the material MF toward the nozzle flow path  74  of the nozzle  73  attached to the through hole  180  of the heating block  190 . The heating block  190  plasticizes the material MF conveyed into the nozzle flow path  74  of the nozzle  73  using heat of a heater (not shown) built in the heating block  190 . 
     The material MF according to the present embodiment is cooled near the inflow port  165  of the nozzle  73  by air sent from the blower  16  described above through the manifold  17 . As a result, plasticization of the material MF in the vicinity of the inflow port  165  is prevented, and the material MF is efficiently conveyed into the inflow port  165 . An outlet end  18  of the manifold  17  is located at the +Z direction side of the shield  92 . As a result, the air sent out from the manifold  17  is easily guided to the vicinity of the inflow port  165  by the shield  92 , and thus the material MF in the vicinity of the inflow port  165  is efficiently cooled. 
     Although the configuration of the cleaning mechanism  250  according to the present embodiment is the same as that in the first embodiment, the tip end of the brush  251  does not come into contact with the shield  92  during the cleaning processing. This is because the shield  92  is located above the heating block  190  in the present embodiment. 
     In the three-dimensional shaping device  13  according to the present embodiment described above as well, it is also possible to clean the nozzle  73  using the cleaning mechanism  250 . In addition, since the nozzle  73  is provided with the memory  66 , it is possible to manage the use of the nozzle  73 . 
     J. Other Embodiments 
     (J1) In the embodiments described above, the nozzle identification information, the material information, the cleaning processing execution history, the cumulative ejection amount, and the nozzle use time are recorded as the nozzle information in the memory  66  provided in the nozzle  60 . Alternatively, the nozzle information may be stored in the storage unit  320  provided in the control unit  300 , and only the nozzle identification information may be recorded in the memory  66 . The control unit  300  can manage the nozzle information for each nozzle  60  by collating the nozzle identification information recorded in the memory  66  of the nozzle  60  with the nozzle identification information stored in the storage unit  320 . 
     Instead of the storage unit  320  provided in the control unit  300 , the nozzle information may be stored in a predetermined server device coupled to the three-dimensional shaping device  10  via a communication line such as the Internet. The control unit  300  can collate the nozzle identification information stored in the memory  66  of the nozzle  60  with the nozzle identification information included in the nozzle information stored in the server device, and can acquire the nozzle information of the nozzle  60  attached to the three-dimensional shaping device from the server device. 
     A plurality of three-dimensional shaping devices may be coupled to the server device. In this manner, the server device centrally manages nozzle information of the nozzles  60  used in the plurality of three-dimensional shaping devices. As a result, for example, even when a nozzle  60  used in another three-dimensional shaping device is attached to the three-dimensional shaping device and used, the nozzle information corresponding to the nozzle  60  can be acquired from the server device, and thus the use of the nozzle  60  can be easily managed. 
     Not only the nozzle information but also the cleaning condition table TB 1  shown in  FIG.  9    and the cleaning condition table TB 2  shown in  FIG.  16    may be stored in the server device. In this manner, the control unit of each three-dimensional shaping device can determine the mode of the cleaning operation and the execution timing of the cleaning processing with reference to the cleaning condition table centrally managed in the server device. 
     (J2) In the first embodiment and the second embodiment described above, the control unit  300  compares the cumulative ejection amount recorded in the memory  66  of the nozzle  60  with the cumulative ejection amount defined in the cleaning condition table TB 1  or the cleaning condition table TB 2 , and determines the mode of the cleaning operation and the execution timing of the cleaning processing. On the other hand, the control unit  300  may determine the mode of the cleaning operation and the execution timing of the cleaning processing by using the nozzle use time recorded in the memory  66 . In this case, the nozzle use time and the mode of the cleaning operation or the execution timing of the cleaning processing are associated with each other in the cleaning condition table TB 1  and the cleaning condition table TB 2 . 
     (J3) In the first embodiment and the second embodiment described above, the control unit  300  determines the mode of the cleaning operation or the execution timing of the cleaning processing based on the material information and the cumulative ejection amount in the nozzle information. On the other hand, the control unit  300  may determine the mode of the cleaning operation or the execution timing of the cleaning processing based on only one of the material information, the cumulative ejection amount, and the nozzle use time. 
     (J4) In the embodiments described above, the control unit  300  moves the nozzle  60  from the blade  252  side to the brush  251  side at the start of the cleaning operation. On the other hand, the control unit  300  may move the nozzle  60  from the brush  251  side to the blade  252  side at the start of the cleaning operation. 
     (J5) In the embodiments described above, the cleaning mechanism  250  includes the purge unit  253 . On the other hand, the cleaning mechanism  250  may not include the purge unit  253 . 
     (J6) In the embodiments described above, the nozzles  60  and  73  include the shields  68  and  92 , respectively. On the other hand, the nozzles  60  and  73  may not include the shields  68  and  92 , respectively. 
     (J7) In the embodiments described above, the cleaning mechanism  250  is disposed in a region different from the stage  220  in the horizontal direction. On the other hand, the cleaning mechanism  250  may be disposed in a region that overlaps the stage  220  in the horizontal direction and that is different from a shaping region of the stage  220  in which the three-dimensional shaped object is shaped. Accordingly, it is possible to provide a compact three-dimensional shaping device. 
     K. Other Aspects 
     The present disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from the scope of the present disclosure. In order to solve a part of or all of the above problems, or to achieve a part of or all of the above effects, technical features in the embodiments described above corresponding to technical features described in the following aspects can be replaced or combined as appropriate. For example, various embodiments described above can be combined as appropriate. Technical features can be deleted as appropriate unless described as essential in the present specification. 
     (1) According to a first aspect of the present disclosure, there is provided a three-dimensional shaping device. The three-dimensional shaping device includes an ejection unit that is provided with a nozzle and a plasticizing mechanism configured to plasticize a plasticizing material to generate a shaping material and that is configured to eject the shaping material from the nozzle; a stage on which the shaping material is stacked; a drive unit configured to change a relative position between the ejection unit and the stage; a cleaning mechanism that is provided with a brush and a blade; and a control unit configured to execute a cleaning processing of cleaning the nozzle and control the ejection unit and the drive unit to stack a layer on the stage, in which the brush and the blade are disposed at a height at which the brush and the blade are contactable with the nozzle, the brush and the blade have a melting point higher than a plasticizing temperature of the plasticizing material and a hardness lower than a hardness of the nozzle, the control unit executes a cleaning operation of bringing at least one of the brush and the blade into contact with the nozzle by causing the nozzle to reciprocate in a manner in which the nozzle crosses the cleaning mechanism for a plurality of times in the cleaning processing, the control unit causes the nozzle to reciprocate such that the nozzle comes into contact with the brush or the blade at different positions in the cleaning operation, and the control unit records at least one of material information on a type of the plasticizing material, a cumulative ejection amount of the shaping material ejected from the nozzle, and a use time of the nozzle in association with the nozzle. 
     According to such an aspect, since the control unit records the nozzle in association with at least one of the material information on the type of the plasticizing material, the cumulative ejection amount of the shaping material, and the use time of the nozzle, it is possible to manage the use of the nozzle so as to avoid unexpected nozzle clogging. Since the control unit causes the nozzle to reciprocate such that the nozzle comes into contact with the brush or the blade at different positions in the cleaning operation, it is possible to prevent a waste material adhering to the cleaning mechanism from re-adhering to the nozzle during the cleaning processing. 
     (2) In the above aspect, the control unit may determine a mode of the cleaning operation or an execution timing of the cleaning processing based on at least one of the material information, the cumulative ejection amount, and the use time of the nozzle. According to such an aspect, the mode of the cleaning operation and the execution timing of the cleaning processing can be changed according to the material information, the cumulative ejection amount, and the use time of the nozzle. 
     (3) In the above aspect, the control unit may determine the execution timing of the cleaning processing for a plurality of times, and an interval from an execution timing of an n-th cleaning processing to an execution timing of an (n+1)-th cleaning processing may be shorter than an interval from an execution timing of an (n−1)-th cleaning processing to the execution timing of an n-th cleaning processing, n being an integer of 2 or more. According to such an aspect, since the cleaning processing is executed at a shorter interval as the number of execution times of the cleaning processing increases, it is possible to prevent frequent occurrence of nozzle clogging due to the progress of deterioration or contamination of the nozzle. Therefore, shaping quality can be improved. 
     (4) In the above aspect, the control unit may determine the execution timing of the cleaning processing for a plurality of times, and a cleaning strength in an (m+1)-th cleaning processing may be stronger than a cleaning strength in an m-th cleaning processing, m being an integer of 1 or more. According to such an aspect, since the cleaning strength becomes stronger as the number of execution times of the cleaning processing increases, it is possible to prevent frequent occurrence of nozzle clogging due to the progress of deterioration or contamination of the nozzle. Therefore, shaping quality can be improved. 
     (5) In the above aspect, when a period from an execution timing of a p-th cleaning processing to an execution timing of a (p+1)-th cleaning processing is shorter than a period determined based on the cumulative ejection amount or the use time of the nozzle, p being an integer of 1 or more, the control unit may not execute the (p+1)-th cleaning processing or may change a start timing of the (p+1)-th cleaning processing. According to such an aspect, it is possible to prevent the cleaning processing from being excessively executed. 
     (6) In the above aspect, when the cleaning processing is executed according to a determined execution timing of an r-th cleaning processing, r being an integer of 1 or more, the control unit may inspect a state of the nozzle before the execution of the cleaning processing, and may change a mode of cleaning operations of the r-th cleaning processing and a subsequent cleaning processing or the execution timing of the cleaning processing based on an inspection result. According to such an aspect, it is possible to prevent the cleaning processing from being excessively executed. 
     (7) In the above aspect, when the plasticizing material is changed, the control unit may change the execution timing of the cleaning processing or the mode of the cleaning operation. According to such an aspect, the cleaning processing can be executed in accordance with the changed plasticizing material. 
     (8) In the above aspect, when the cleaning processing is executed, the control unit may record a cleaning processing execution history in association with the cumulative ejection amount or the use time of the nozzle. 
     (9) According to a second aspect of the present disclosure, there is provided a method for manufacturing a three-dimensional shaped object in a three-dimensional shaping device. The three-dimensional shaping device includes: an ejection unit that is provided with a nozzle and a plasticizing mechanism configured to plasticize a plasticizing material to generate a shaping material and that is configured to eject the shaping material from the nozzle; a stage on which the shaping material is stacked; a drive unit configured to change a relative position between the ejection unit and the stage; and a cleaning mechanism provided with a brush and a blade, in which the brush and the blade are disposed at a height at which the brush and the blade are contactable with the nozzle, and the brush and the blade have a melting point higher than a plasticizing temperature of the plasticizing material and a hardness lower than a hardness of the nozzle. The manufacturing method includes: a stacking step of stacking a layer on the stage by controlling the ejection unit and the drive unit; a cleaning step of executing a cleaning operation of bringing at least one of the brush and the blade into contact with the nozzle by causing the nozzle to reciprocate in a manner in which the nozzle crosses the cleaning mechanism for a plurality of times, in which in the cleaning step, the nozzle reciprocates such that the nozzle comes into contact with the brush or the blade at different positions in the cleaning operation, and at least one of material information on a type of the plasticizing material, a cumulative ejection amount of the shaping material ejected from the nozzle, and a use time of the nozzle is recorded in association with the nozzle.