Patent Description:
For example, <CIT> discloses a three-dimensional shaping device that includes a nozzle that discharges a melt material and a suction unit that suctions the material in the nozzle. A further example of a three-dimensional shaping device is described in <CIT>. In the three-dimensional shaping device, it is desired to prevent stretching of a material which stretches like a thread between a three-dimensional shaped object and the nozzle by driving the suction unit and suctioning the material in the nozzle when the nozzle is moved away after the material is discharged from the nozzle.

In the three-dimensional shaping device described above, for example, when the time required for the movement of the nozzle is long, the material may be unintentionally discharged from the nozzle. Therefore, there is a possibility that the material discharged from the nozzle unintentionally adheres to the three-dimensional shaped object, thereby reducing the dimensional accuracy of the three-dimensional shaped object.

According to one aspect of the present invention, as disclosed in claim <NUM>, a three-dimensional shaping device is provided. The three-dimensional shaping device includes a melting unit configured to melt a material into a shaping material, and a nozzle configured to discharge the shaping material supplied from the melting unit toward a stage. The melting unit includes a screw configured to rotate about a rotation axis and including a groove forming surface in which a groove to which the material is supplied is formed, a heating unit configured to heat the material that is supplied to the groove, a barrel having a facing surface that faces the groove forming surface and provided with a communication hole that communicates the facing surface with the nozzle, and a discharge amount adjustment mechanism provided in the communication hole and configured to adjust a flow rate of the shaping material discharged from the nozzle.

<FIG> is an illustrative diagram showing a schematic configuration of a three-dimensional shaping device <NUM> according to the first embodiment. In <FIG>, arrows along X, Y, and Z directions which are orthogonal to each other are shown. The X direction and the Y direction are directions along a horizontal direction and the Z direction is a direction along a vertical direction. In other drawings, the arrows along the X, Y, and Z directions are shown as appropriate. The X, Y, and Z directions in <FIG> indicate the same directions as the X, Y, and Z directions in other drawings.

The three-dimensional shaping device <NUM> according to the present embodiment includes a shaping head <NUM>, a stage <NUM>, a moving mechanism <NUM>, and a control unit <NUM>. Under control of the control unit <NUM>, the three-dimensional shaping device <NUM> drives the moving mechanism <NUM> to change a relative position between a nozzle <NUM> and a shaping surface <NUM> while discharging a shaping material from the nozzle <NUM> provided in the shaping head <NUM> toward the shaping surface <NUM> of the stage <NUM> to shape a three-dimensional shaped object having a desired shape on the shaping surface <NUM>.

The moving mechanism <NUM> changes a relative position between the nozzle <NUM> and the shaping surface <NUM>. In the present embodiment, the moving mechanism <NUM> changes the relative position between the nozzle <NUM> and the shaping surface <NUM> by moving the stage <NUM> with respect to the shaping head <NUM>. The moving mechanism <NUM> in the present embodiment is constituted by a three-axis positioner that moves the stage <NUM> in three axial directions that are the X direction, the Y direction and the Z direction by driving force of three motors. Each motor is driven under control of the control unit <NUM>. Instead of moving the stage <NUM>, the moving mechanism <NUM> may be configured to change the relative position between the nozzle <NUM> and the shaping surface <NUM> by moving the shaping head <NUM> without moving the stage <NUM>. Further, the moving mechanism <NUM> may be configured to change the relative position between the nozzle <NUM> and the shaping surface <NUM> by moving both the stage <NUM> and the shaping head <NUM>.

The control unit <NUM> is constituted by a computer including one or more processor, a main storage device, and an input and output interface that inputs and outputs signals from and to the outside. In the present embodiment, the control unit <NUM> controls operations of the shaping head <NUM> and the moving mechanism <NUM> by executing a program or a command read on the main storage device with the processor, thereby executing a shaping processing for forming the three-dimensional shaped object. The operations include movement of a three-dimensional relative position between the shaping head <NUM> and the stage <NUM>. The control unit <NUM> may be constituted by a combination of a plurality of circuits instead of the computer.

The shaping head <NUM> includes a material supply unit <NUM> which is a material supply source, a melting unit <NUM> that melts a material supplied from the material supply unit <NUM> to make the material into a shaping material, and the nozzle <NUM> that discharges the shaping material supplied from the melting unit <NUM>. The material supply unit <NUM> contains a material in a state of pellets, powder, or the like. In the present embodiment, an ABS resin formed in the shape of a pellet is used as the material. The material supply unit <NUM> in the present embodiment is constituted by a hopper. A supply path <NUM> that couples the material supply unit <NUM> to the melting unit <NUM> is provided below the material supply unit <NUM>. The material supply unit <NUM> supplies the material to the melting unit <NUM> via the supply path <NUM>.

The melting unit <NUM> includes a screw case <NUM>, a drive motor <NUM>, a flat screw <NUM>, and a barrel <NUM>. The melting section <NUM> melts at least a part of the material in a solid state supplied from the material supply unit <NUM> into a shaping material in a paste form having fluidity, and supplies the molten material to the nozzle <NUM>. The flat screw <NUM> is sometimes simply referred to as a screw.

The screw case <NUM> is a housing that accommodates the flat screw <NUM>. The barrel <NUM> is fixed to a lower surface of the screw case <NUM>, and a flat screw <NUM> is accommodated in a space surrounded by the screw case <NUM> and the barrel <NUM>. The drive motor <NUM> is fixed to an upper surface of the screw case <NUM>. A shaft <NUM> of the drive motor <NUM> is coupled to an upper surface <NUM> side of the flat screw <NUM>. The drive motor <NUM> is driven under the control of the control unit <NUM>.

The flat screw <NUM> has a substantially cylindrical shape whose height in a direction along a central axis RX is smaller than a diameter. The flat screw <NUM> is disposed in the screw case <NUM> in a manner that the central axis RX is parallel to the Z direction. The flat screw <NUM> rotates around the central axis RX in the screw case <NUM> by a torque generated by the drive motor <NUM>. The flat screw <NUM> includes a groove forming surface <NUM> in which a groove <NUM> into which a material is supplied is formed on a side opposite to the upper surface <NUM> in a direction along the central axis RX. The central axis RX may be referred to as a rotation axis. A specific configuration of the groove forming surface <NUM> will be described later.

The barrel <NUM> is disposed below the flat screw <NUM>. The barrel <NUM> includes a screw facing surface <NUM> that faces the groove forming surface <NUM> of the flat screw <NUM>. The barrel <NUM> is provided with a communication hole <NUM> communicating the screw facing surface <NUM> with the nozzle <NUM>, and an intersecting hole <NUM> intersecting the communication hole <NUM>. A part of the communication hole <NUM> intersecting the intersecting hole <NUM> is referred to as an intersecting portion <NUM>. The communication hole <NUM> includes a first partial flow path <NUM> that is closer to the screw facing surface <NUM> than the intersecting portion <NUM>, and a second partial flow path <NUM> that is further away from the screw facing surface <NUM> than the intersecting portion <NUM>. In the present embodiment, the first partial flow path <NUM> and the second partial flow path <NUM> extend on the central axis RX of the flat screw <NUM> along the Z direction. The intersecting hole <NUM> extends along the Y direction. The screw facing surface <NUM> may be simply referred to as a facing surface. A specific configuration of the screw facing surface <NUM> will be described later.

The barrel <NUM> is provided with a discharge amount adjustment mechanism <NUM> that adjusts a flow rate of the shaping material discharged from the nozzle <NUM>. The discharge amount adjustment mechanism <NUM> includes a valve portion <NUM> disposed in the intersecting hole <NUM> and a valve drive portion <NUM> that rotates the valve portion <NUM> in the intersecting hole <NUM>. The valve drive portion <NUM> is configured by an actuator such as a stepping motor, and rotates the valve portion <NUM> under control of the control unit <NUM>. A suction unit <NUM> is coupled to the second partial flow path <NUM> of the communication hole <NUM>. The suction unit <NUM> suctions the shaping material from the second partial flow path <NUM>. It can be said that the valve portion <NUM> rotates within the intersecting portion <NUM> of the communication hole <NUM>. A flow rate of the shaping material discharged from the nozzle <NUM> is also referred to as a discharge amount. A specific configuration of the discharge amount adjustment mechanism <NUM> and a specific configuration of the suction unit <NUM> will be described later.

The barrel <NUM> includes a heater <NUM> that heats the material supplied to the groove <NUM> of the flat screw <NUM>. In the present embodiment, shaft-shaped heaters 58A to 58D extending along the Y direction are embedded in the barrel <NUM>. The heaters 58A to 58D are disposed below the groove <NUM> of the flat screw <NUM> in the barrel <NUM>. The heaters 58A to 58D are disposed in a manner that a position of each of the heaters 58A to 58D in the Z direction is the same as the position of the valve portion <NUM> of the discharge amount adjustment mechanism <NUM> in the Z direction. The heater 58A, the heater 58B, the valve portion <NUM> of the discharge amount adjustment mechanism <NUM>, the heater 58C, and the heater 58D are disposed in parallel in the above order from a -X direction side to a +X direction side. The heater 58A and the heater 58B are disposed in a cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to a central axis AX1 of the valve portion <NUM>, in a manner that a shortest distance between the communication hole <NUM> and the heater 58B in the X direction which is a direction perpendicular to the central axis RX of the flat screw <NUM> is the same as a shortest distance between an outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> and the heater 58A in the X direction. The heater 58C and the heater 58D are disposed in a cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to a central axis AX1 of the valve portion <NUM>, in a manner that a shortest distance between the communication hole <NUM> and the heater 58C in the X direction is the same as a shortest distance between the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> and the heater 58D in the X direction. Temperature of each of the heaters <NUM> A to <NUM> D is controlled by the control unit <NUM>. The heater <NUM> may also be referred to as a heating unit.

The barrel <NUM> includes a cooling unit <NUM> that cools the flat screw <NUM> and the barrel <NUM>. In the present embodiment, the cooling unit <NUM> includes a refrigerant pipe <NUM> embedded in the barrel <NUM> and a pump <NUM> coupled to the refrigerant pipe <NUM> to supply refrigerant to the refrigerant pipe <NUM>. Each refrigerant pipe <NUM> is disposed at a position further away from the communication hole <NUM> than each heater <NUM>. The refrigerant pipe <NUM> is disposed so as to pass through a vicinity of the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM>. The refrigerant pipe <NUM> is disposed in a cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM> in a manner that a shortest distance between the refrigerant pipe <NUM> and the communication hole <NUM> in X direction is longer than a shortest distance between the refrigerant pipe <NUM> and the outer peripheral edge of the groove forming surface <NUM> in the X direction which is a direction perpendicular to the central axis RX of the flat screw <NUM>. The pump <NUM> is driven under the control of the control unit <NUM>. In the present embodiment, water is used as the refrigerant. As the refrigerant, for example, a liquid such as oil or a gas such as carbon dioxide may be used. A peltier element or a heat pump may be used for the cooling unit <NUM>.

The nozzle <NUM> is coupled to a lower surface of the barrel <NUM>. The nozzle <NUM> is provided with a nozzle hole <NUM> at a tip portion of the nozzle <NUM> facing the shaping surface <NUM> of the stage <NUM>. The nozzle hole <NUM> is an opening that discharges the shaping material. The second partial flow path <NUM> and the nozzle hole <NUM> of the communication hole <NUM> provided in the barrel <NUM> communicate with each other via an internal flow path <NUM>. In the present embodiment, an opening shape of the nozzle hole <NUM> is circular. A diameter of the nozzle hole <NUM> is smaller than a diameter of the internal flow path <NUM>. The opening shape of the nozzle hole <NUM> is not limited to a circular shape, and may be a square shape or the like.

<FIG> is an illustrative view showing a configuration of the discharge amount adjustment mechanism <NUM> and the suction unit <NUM> in the present embodiment. <FIG> is a perspective view showing a configuration of the valve portion <NUM> of the discharge amount adjustment mechanism <NUM> in the present embodiment. As described above, the discharge amount adjustment mechanism <NUM> has a columnar valve portion <NUM> disposed in the intersecting hole <NUM>. The valve portion <NUM> has a central axis AX1. The valve portion <NUM> is provided with a recess <NUM> by partially cutting out a part of the cylindrical outer circumference in a half-moon shape. The recess <NUM> is disposed in the intersecting portion <NUM> of the communication hole <NUM>. An operation unit <NUM> is provided at an end portion on a -Y direction side of the valve portion <NUM>. A valve drive unit <NUM> is coupled to the operation unit <NUM>. When the torque by the valve drive unit <NUM> is applied to the operation unit <NUM>, the valve portion <NUM> rotates. The recess <NUM> may also be referred to as a flow path.

<FIG> is a first illustrative view showing an operation of the valve portion <NUM> of the discharge amount adjustment mechanism <NUM>. <FIG> is a second illustrative view showing an operation of the valve portion <NUM> of the discharge amount adjustment mechanism <NUM>. As shown in <FIG>, when the valve portion <NUM> rotates such that the recess <NUM> is positioned above, the second partial flow path <NUM> is closed by the valve portion <NUM>, and inflow of the shaping material from the first partial flow path <NUM> to the second partial flow path <NUM> is blocked. On the other hand, as shown in <FIG>, when the valve portion <NUM> rotates such that the recess <NUM> faces the +X direction or the -X direction, the first partial flow path <NUM> and the second partial flow path <NUM> communicate with each other, and the shaping material flows from the first partial flow path <NUM> to the second partial flow path <NUM> at a maximum flow rate. The discharge amount adjustment mechanism <NUM> changes a cross-sectional area of the flow path between the first partial flow path <NUM> and the second partial flow path <NUM> in response to the rotation of the valve portion <NUM>, and changes the flow rate of the shaping material flowing from the first partial flow path <NUM> to the second partial flow path <NUM>.

Referring to <FIG>, the suction unit <NUM> according to the present embodiment includes a cylindrical cylinder <NUM> embedded in the barrel <NUM>, a plunger <NUM> accommodated in the cylinder <NUM>, and a plunger driving unit <NUM> that moves the plunger <NUM> in the cylinder <NUM>. The cylinder <NUM> is coupled to the second partial flow path <NUM> of the communication hole <NUM>. The plunger driving unit <NUM> includes a motor driven under the control of the control unit <NUM>, and a rack and pinion that converts the rotation of the motor into translational motion along a central axis AX2 of the cylinder <NUM>. The plunger driving unit <NUM> may be constituted by a motor driven under the control of the control unit <NUM> and a ball screw that converts the rotation of the motor into translational motion along the central axis AX2 of the cylinder <NUM>, or may be constituted by an actuator such as a solenoid mechanism or a piezo element.

<FIG> is an illustrative view showing an operation of the plunger <NUM> of the suction unit <NUM>. When the plunger <NUM> moves in a direction away from the second partial flow path <NUM> of the communication hole <NUM>, a negative pressure is generated in the cylinder <NUM>, so that the shaping material in the second partial flow path <NUM> is drawn into the cylinder <NUM> as indicated by an arrow in <FIG>. As the shaping material in the second partial flow path <NUM> is drawn into the cylinder <NUM>, the shaping material in the nozzle <NUM> is drawn into the second partial flow path <NUM>. Therefore, when the discharge of the shaping material from the nozzle <NUM> is stopped, the shaping material in the second partial flow path <NUM> is suctioned into the cylinder <NUM>, so that the shaping material discharged from the nozzle <NUM> can be cut off. On the other hand, when the plunger <NUM> moves in a direction closer to the second partial flow path <NUM>, the shaping material in the cylinder <NUM> is pushed into the second partial flow path <NUM> by the plunger <NUM>. Therefore, when the discharge of the shaping material from the nozzle <NUM> is restarted, the shaping material in the cylinder <NUM> is pushed into the second partial flow path <NUM>, thereby responsivity of the discharge of the shaping material from the nozzle <NUM> can be improved. The movement of the plunger <NUM> in the direction away from the second partial flow path <NUM> is also referred to as pulling the plunger <NUM>. The movement of the plunger <NUM> in the direction closer to the second partial flow path <NUM> is referred to as pushing the plunger <NUM>.

<FIG> is a perspective view showing a configuration of the groove forming surface <NUM> of the flat screw <NUM> in the present embodiment. In order to facilitate understanding of the technology, the flat screw <NUM> in <FIG> is shown in a reversed state of a vertical positional relationship shown in <FIG>. The groove forming surface <NUM> of the flat screw <NUM> is provided with a central portion <NUM>, a groove <NUM>, and a material introduction port <NUM>. The central portion <NUM> is a depression formed around the central axis RX of the flat screw <NUM>. The central portion <NUM> faces the communication hole <NUM> of the barrel <NUM>.

The groove <NUM> is a groove that extends spirally around the central axis RX of the flat screw <NUM> in a manner of drawing an arc toward the outer periphery of the groove forming surface <NUM>. The groove <NUM> may be configured to extend in an involute curve shape or a spiral shape. One end of the groove <NUM> is coupled to the central portion <NUM>, and the other end of the groove <NUM> is coupled to the material introduction port <NUM>. Adjacent grooves <NUM> are partitioned by ridge portions <NUM>.

The material introduction port <NUM> is provided on a side surface <NUM> of the flat screw <NUM>. The material introduction port <NUM> introduces the material supplied from the material supply unit <NUM> through the supply path <NUM> into the groove <NUM>. Although a mode is illustrated in <FIG>, in which one groove <NUM> extending from the central portion <NUM> toward the outer periphery of the flat screw <NUM> and one material introduction port <NUM> are provided, a plurality of grooves <NUM> extending from the central portion <NUM> toward the outer periphery of the flat screw <NUM> and a plurality of material introduction ports <NUM> may be provided.

<FIG> is a top view showing a configuration of the screw facing surface <NUM> of the barrel <NUM> according to the present embodiment. As described above, the communication hole <NUM> communicating with the nozzle <NUM> is formed at the center of the screw facing surface <NUM>. A plurality of guide grooves <NUM> are formed around the communication hole <NUM> in the screw facing surface <NUM>. One end of each guide groove <NUM> is coupled to the communication hole <NUM>, and extends spirally from the communication hole <NUM> toward the outer periphery of the screw facing surface <NUM>. Each of the guide grooves <NUM> has a function of guiding the shaping material to the communication hole <NUM>.

<FIG> is a flowchart showing a content of the shaping processing according to the present embodiment. The processing is executed by the control unit <NUM> when a user performs a predetermined start operation on an operation panel provided in the three-dimensional shaping device <NUM> or a computer coupled to the three-dimensional shaping device <NUM>.

First, in step S110, the control unit <NUM> acquires shaping data for shaping a three-dimensional shaped object OB. The shaping data is data which represents information related to a moving path of the nozzle <NUM> with respect to the shaping surface <NUM> of the stage <NUM>, an amount of the shaping material discharged from the nozzle <NUM>, a rotational speed of the driving motor <NUM> that rotates the flat screw <NUM>, or the temperature of the heater <NUM> built in the barrel <NUM>. The shaping data is generated by, for example, slicer software installed in a computer coupled to the three-dimensional shaping device <NUM>. The slicer software reads shape data representing a shape of the three-dimensional shaped object OB that is generated using three-dimensional CAD software or three-dimensional CG software, divides the shape of the three-dimensional shaped object OB into layers having a predetermined thickness to generate the shaping data. The shape data read by the slicer software is data in an STL format, an AMF format, or the like. The shaping data created by the slicer software is represented by a G code, an M code, or the like. The control unit <NUM> acquires the shaping data from the computer coupled to the three-dimensional shaping device <NUM> or a recording medium such as a USB memory.

Next, in step S120, the control unit <NUM> starts generating the shaping material. The control unit <NUM> controls the rotation of the flat screw <NUM> and the temperature of the heater <NUM> in accordance with the shaping data to melt the material and to generate the shaping material. By the rotation of the flat screw <NUM>, the material supplied from the material supply unit <NUM> is introduced into the groove <NUM> from the material introduction port <NUM> of the flat screw <NUM>. The material introduced into the groove <NUM> is conveyed to the central portion <NUM> along the groove <NUM>. The material conveyed in the groove <NUM> is sheared by relative rotation between flat screw <NUM> and barrel <NUM>, and at least a part of the material is melted by heating with the heater <NUM>, resulting in a shaping material in a paste form having fluidity. The shaping material collected in the central portion <NUM> is pressure-fed from the communication hole <NUM> to the nozzle <NUM>. The shaping material continues to be generated while the process is performed.

In step S130, the control unit <NUM> controls the discharge amount adjustment mechanism <NUM> to communicate the first partial flow path <NUM> with the second partial flow path <NUM> of the communication hole <NUM>, so as to start discharging the shaping material from the nozzle <NUM>. By starting the discharge of the shaping material from the nozzle <NUM>, shaping of the three-dimensional shaped object OB is started.

In step S140, the control unit <NUM> determines whether the discharge of the shaping material from the nozzle <NUM> is stopped. If it is determined in step S140 that the discharge of the shaping material from the nozzle <NUM> is not stopped, the control unit <NUM> continues the shaping of the three-dimensional shaped object OB while repeating the process of step S140 until it is determined that the discharge of the shaping material from the nozzle <NUM> is stopped. On the other hand, if it is determined in step S140 that the discharge of the shaping material from the nozzle <NUM> is stopped, in step S150, the control unit <NUM> controls the discharge amount adjustment mechanism <NUM> to block inflow of the shaping material from the first partial flow path <NUM> to the second partial flow path <NUM> of the communication hole <NUM>. By blocking the inflow of the shaping material from the first partial flow path <NUM> to the second partial flow path <NUM>, the discharge of the shaping material from the nozzle <NUM> is stopped. When the discharge of the shaping material from the nozzle <NUM> is stopped, in step S155, the control unit <NUM> controls the plunger driving unit <NUM> to draw the shaping material remaining in the nozzle <NUM> or the second partial flow path <NUM> into the cylinder <NUM> by pulling the plunger <NUM>.

Thereafter, in step S160, the control unit <NUM> determines whether the shaping of the three-dimensional shaped object OB was completed. If it is determined in step S160 that the shaping of the three-dimensional shaped object OB was completed, the control unit <NUM> ends the processing. On the other hand, if it is determined in step S160 that the shaping of the three-dimensional shaped object OB has not been completed, in step S170, the control unit <NUM> determines whether to restart the discharge of the shaping material from the nozzle <NUM>.

If it is determined in step S170 that the discharge of the shaping material from the nozzle <NUM> is not restarted, the control unit <NUM> waits for shaping of the three-dimensional shaped object OB while repeating the process of step S170 until it is determined that the discharge of the shaping material from the nozzle <NUM> is restarted. On the other hand, if it is determined in step S170 that the discharge of the shaping material from the nozzle <NUM> is restarted, in step S180, the control unit <NUM> controls the discharge amount adjustment mechanism <NUM> to communicate the first partial flow path <NUM> with the second partial flow path <NUM>. By communicating the first partial flow path <NUM> with the second partial flow path <NUM>, discharge of the shaping material from the nozzle <NUM> is restarted. When the discharge of the shaping material from the nozzle <NUM> is restarted, in step S185, the control unit <NUM> controls the plunger driving unit <NUM> to push the plunger <NUM>. When the plunger <NUM> is pushed, the shaping material in the cylinder <NUM> is discharged into the second partial flow path <NUM>, so that the discharge of the shaping material from the nozzle <NUM> is quickly restarted.

<FIG> is an illustrative diagram schematically showing a state in which the three-dimensional shaped object OB is shaped. After step S185 shown in <FIG>, the processing of the control unit <NUM> returns to step S140, and the control unit <NUM> continues shaping of the three-dimensional shaped object OB until it is determined in step S160 that the shaping of the three-dimensional object OB was completed. In this manner, a three-dimensional shaped object OB having a desired shape is formed on the stage <NUM>.

<FIG> is an illustrative view showing a three-dimensional shaping device 100b in a comparative example. Different from the present embodiment, in the comparative example, a flow path structure <NUM> is provided between a barrel 50b and the nozzle <NUM>, and the discharge amount adjustment mechanism <NUM> and the suction unit <NUM> are provided in the flow path structure <NUM> instead of the barrel 50b. That is, different from the present embodiment, in the comparative example, the discharge amount adjustment mechanism <NUM> and the suction unit <NUM> are constituted as separate units from the barrel <NUM>. Other configurations are the same as those of the present embodiment unless otherwise described. The barrel 50b is provided with a first communication hole 56b. The flow path structure <NUM> is provided with a second communication hole <NUM> communicating the first communication hole 56b of the barrel 50b with the nozzle <NUM>, and an intersecting hole <NUM> intersecting the second communication hole <NUM>. The first communication hole 56b and the second communication hole <NUM> extend on the central axis RX of the flat screw <NUM> along the Z direction. The valve portion <NUM> of the discharge amount adjustment mechanism <NUM> is disposed in the intersecting hole <NUM>. The cylinder <NUM> of the suction unit <NUM> is coupled to the second communication hole <NUM>. A shortest distance L2 from the screw facing surface 52b to the opening of the nozzle hole <NUM> in the comparative example is longer than a shortest distance L1 from the screw facing surface <NUM> to the opening of the nozzle hole <NUM> in the present embodiment. Therefore, a pressure loss of the shaping material when the shaping material flows from the screw facing surface 52b to the opening of the nozzle hole <NUM> in the comparative example is larger than the pressure loss of the shaping material when the shaping material flows from the screw facing surface <NUM> to the opening of the nozzle hole <NUM> in the present embodiment.

According to the three-dimensional shaping device <NUM> of the present embodiment described above, since the supply of the shaping material to the nozzle <NUM> can be stopped by the discharge amount adjustment mechanism <NUM> provided in the barrel <NUM>, it is possible to prevent unintentional discharge of the shaping material from the nozzle <NUM>. Therefore, it is possible to prevent the material unintentionally discharged from the nozzle <NUM> from adhering to the three-dimensional shaped object OB, and thus prevent reduction of dimensional accuracy of the three-dimensional shaped object OB. In particular, in the present embodiment, since the barrel <NUM> and the discharge amount adjustment mechanism <NUM> are constituted in one unit, the shortest distance L1 from the screw facing surface <NUM> to the opening of the nozzle hole <NUM> can be set shorter than that in a configuration in which the barrel <NUM> and the discharge amount adjustment mechanism <NUM> are constituted as separate units. Therefore, since the pressure loss of the shaping material when the shaping material flows from the screw facing surface <NUM> to the opening of the nozzle hole <NUM> can be set to be small, it is possible to easily ensure the discharge amount of the shaping material from the nozzle <NUM>. Further, since the minimum distance between the heater <NUM> incorporated in the barrel <NUM> and the nozzle <NUM> can be set to be short by constituting the barrel <NUM> and the discharge amount adjustment mechanism <NUM> in one unit, the heater <NUM> provided in the barrel <NUM> can heat the shaping material in the second partial flow path <NUM> of the communication hole <NUM> and the nozzle <NUM>. Therefore, the structure can be simplified and the control of the temperature of the heater <NUM> by the control unit <NUM> can be easier as compared with a configuration in which a heater is separately provided in the vicinity of the second partial flow path <NUM> or in the vicinity of the nozzle <NUM> in order to heat the shaping material in the second partial flow path <NUM> or in the nozzle <NUM>.

In the present embodiment, the control unit <NUM> controls the valve drive portion <NUM> to rotate the valve portion <NUM>, thereby switching between start and stop of the supply of the shaping material to the nozzle <NUM>. Therefore, the start and stop of the discharge of the shaping material from the nozzle <NUM> can be switched by a simple configuration.

In the present embodiment, since the vicinity of the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> can be cooled by the cooling unit <NUM>, it is possible to prevent the temperature in the vicinity of the outer peripheral edge of the groove forming surface <NUM> from becoming too high and to prevent the material conveyance from being hindered. Therefore, the material can be easily conveyed from the outer peripheral edge of the groove forming surface <NUM> toward the central axis RX.

In the present embodiment, when the discharge of the shaping material from the nozzle <NUM> is stopped, the shaping material in the second partial flow path <NUM> of the communication hole <NUM> can be suctioned by the suction unit <NUM>. Therefore, when the discharge of the shaping material from the nozzle <NUM> is stopped by the discharge amount adjustment mechanism <NUM>, the discharge of the shaping material from the nozzle <NUM> can be stopped more quickly.

Although the ABS resin in a pellet form is used as the material in the present embodiment, an example of the material that is used in the shaping head <NUM> may include a material for shaping the three-dimensional shaped object that uses various materials such as a thermoplastic material, a metal material, and a ceramic material as a main material. Here, the "main material" means a material serving as a main component used for shaping the shape of the three-dimensional shaped object and means a material that occupies a content of <NUM>% by weight or more in the three-dimensional shaped object. The shaping material described above includes a material obtained by melting one of the main materials as a simple substance, or a material obtained by melting a part of components containing the main materials into a paste form.

When a thermoplastic material is used as the main material, the shaping material is generated by plasticizing the material in the melting unit <NUM>. "Plasticize" means to melt the thermoplastic material by heating the thermoplastic material. In addition, "melt" means that a thermoplastic material is softened by being heated to a temperature equal to or higher than a glass transition point, thereby exhibiting fluidity.

As the thermoplastic material, for example, any one thermoplastic resin material or a combination of two or more thermoplastic resin materials listed below can be used.

General-purpose engineering plastics such as a polypropylene resin (PP), a polyethylene resin (PE), a polyacetal resin (POM), a polyvinyl chloride resin (PVC), a polyamide resin (PA), an acrylonitrile-butadiene-styrene resin (ABS), a polylactic acid resin (PLA), a polyphenylene sulfide resin (PPS), polycarbonate (PC), modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate, and engineering plastics such as polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate, polyimide, polyamide-imide, polyetherimide, and polyether ether ketone (PEEK).

Additives such as a pigment, a metal, a ceramic, and other additives such as a wax, a flame retardant, an antioxidant, and a heat stabilizer may be mixed into the thermoplastic material. The thermoplastic material is converted into a melted state after being plasticized by the rotation of the flat screw <NUM> and the heating of the heater <NUM> in the melting unit <NUM>. The shaping material generated in such a manner is discharged from the nozzle hole <NUM> and thereafter is hardened due to low temperature.

It is desirable that the thermoplastic material is emitted from the nozzle hole <NUM> in a completely melted state after being heated to the temperature equal to or higher than the glass transition point. The term "completely melted state" means a state in which no unmelted thermoplastic material is present. For example, when a pellet-shaped thermoplastic resin is used as a material, the "completely melted state" means a state in which a pellet-shaped solid matter does not remain.

The following metal material, for example, may be used as the main material in the shaping head <NUM> instead of the above-described thermoplastic material. In this case, it is desirable that a powder material obtained by making the following metal materials into a powder form is mixed with a component that melts at the time of generating the shaping material, and is put into the melting unit <NUM>.

Single metals such as magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), nickel (Ni), or an alloy containing one or more of the metals.

Maraging steel, stainless steel, a cobalt chrome molybdenum alloy, a titanium alloy, a nickel alloy, an aluminum alloy, a cobalt alloy, and a cobalt chromium alloy.

A ceramic material can be used as the main material in the shaping head <NUM> instead of the above-described metal materials. As the ceramic material, for example, an oxide ceramic such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, and a non-oxide ceramic such as aluminum nitride can be used. When the metal material or the ceramic material as described above is used as the main material, the shaping material disposed on the stage <NUM> may be hardened by, for example, irradiating with a laser and sintering with warm air or the like.

A powder material of the metal material or the ceramic material that is put into the material supply unit <NUM> may be a mixed material obtained by mixing a plurality of powders of single metals, a plurality of powders of alloys, and a plurality of powders of ceramic materials. The powder material of the metal material or the ceramic material may be coated with, for example, a thermoplastic resin as exemplified above, or a thermoplastic resin other than the thermoplastic resins. In this case, in the melting unit <NUM>, the thermoplastic resin may be melted to exhibit fluidity.

For example, the following solvents may be added to the powder material of the metal material or the ceramic material that is put into the material supply unit <NUM>. One solvent or a combination of two or more solvents selected from the following solvents may be used.

Water; (poly) alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; acetic acid esters such as ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, and iso-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl-n-butyl ketone, diisopropyl ketone, and acetylacetone; alcohols such as ethanol, propanol, and butanol; tetraalkylammonium acetates; sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide; pyridine-based solvents such as pyridine, γ-picoline, and <NUM>-<NUM>-lutidine; tetraalkylammonium acetates (such as tetrabutylammonium acetate); and ionic liquids such as butyl carbitol acetate.

In addition, the following binder, for example, may be added to the powder material of the metal material or the ceramic material that is put into the material supply unit <NUM>.

An acrylic resin, an epoxy resin, a silicone resin, a cellulose-based resin or other synthetic resins, and a polylactic acid (PLA), a polyamide (PA), a polyphenylene sulfide (PPS), a polyether ether ketone (PEEK) or other thermoplastic resins.

<FIG> is an illustrative diagram showing a schematic configuration of a three-dimensional shaping device 100c according to the second embodiment. In the second embodiment, the arrangement of the heaters 58A to 58D in a barrel 50c of a melting unit 30c having a shaping head 200c is different from the arrangement in the first embodiment. Other configurations are the same as those of the first embodiment shown in <FIG> unless otherwise specified.

In the present embodiment, the heater 58A and the heater 58B are disposed in the barrel 50c in the cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM>, in a manner that a shortest distance L3 between the communication hole <NUM> and the heater 58B in the X direction which is the direction perpendicular to the central axis RX of the flat screw <NUM> is shorter than a shortest distance L4 between the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> and the heater 58A in the X direction. The heater 58A and the heater 58B are disposed in the barrel 50c in the cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM>, in a manner that a shortest distance L5 between the communication hole <NUM> and the heater 58C in the X direction is shorter than a shortest distance L6 between the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> and the heater 58D in the X direction.

According to the three-dimensional shaping device 100c of the present embodiment described above, the shortest distance between the heaters 58A to 58D and the communication hole <NUM> can be set to be short, and the shortest distance between the heaters 58A to 58D and the outer peripheral edge of the groove forming surface <NUM> can be set to be long. Therefore, by heating from the heaters 58A to 58D, and fluidity of the shaping material flowing through the communication hole <NUM> can be improved when the material supplied to the groove <NUM> of the flat screw <NUM> is melted. In particular, in the present embodiment, the shortest distance between the heaters 58A to 58D and the nozzle <NUM> can be set to be short. Therefore, the fluidity of the shaping material discharged from the nozzle <NUM> can be improved by heating from the heaters 58A to 58D.

(C1) <FIG> is an illustrative diagram showing a configuration of a three-dimensional shaping device 100d according to another embodiment. The heater <NUM> that heats the material supplied to the groove <NUM> of the flat screw <NUM> is embedded in the main bodies of the barrels <NUM> and 50c in the melting units <NUM> and 30c of the three-dimensional shaping devices <NUM> and 100c of the embodiments described above. In contrast, as shown in <FIG>, in a melting unit 30d of the three-dimensional shaping device 100d, a heater 58d that heats the material supplied to the groove <NUM> may be embedded in a valve portion 73d of a discharge amount adjustment mechanism 70d instead of the main body of a barrel 50d. An intersecting hole 57d provided in the barrel 50d may extend from a side surface on the -Y direction side of the barrel 50d to the vicinity below the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> on the +Y direction side. The intersecting hole 57d may pass through the barrel 50d. The valve portion 73d of the discharge amount adjustment mechanism 70d may extend to the vicinity below the outer peripheral edge of the groove forming surface <NUM> of the flat screw <NUM> on the +Y direction side. The heater 58d is preferably disposed below the groove <NUM> in the valve portion 73d. Thermal conductivity of an operation unit 77d of the discharge amount adjustment mechanism 70d is preferably set to be smaller than thermal conductivity of the valve portion 73d. For example, the thermal conductivity of the operation unit 77d can be set to be smaller than the thermal conductivity of the valve portion 73d by using a material having a lower thermal conductivity than that of the material of the valve portion 73d in the material of the operation unit 77d. The thermal conductivity of the operation unit 77d can be set to be smaller than the thermal conductivity of the valve portion 73d by forming a zirconia coating on the operation unit 77d. By setting the thermal conductivity of the operation unit 77d to be smaller than the thermal conductivity of the valve portion 73d, the heat of the heater 58d can be prevented from being transmitted to the valve drive portion <NUM> via the operation unit 77d. Therefore, temperature of the valve drive unit <NUM> prevented from being excessively high.

(C2) In the three-dimensional shaping devices <NUM> and 100c of the embodiments described above, the discharge amount adjustment mechanism <NUM> may be, for example, a gate valve, a globe valve, a ball valve, or the like instead of the valve portion <NUM> provided with the recess <NUM>.

(C3) In the three-dimensional shaping devices <NUM> and 100c of the embodiments described above, the suction unit <NUM> is provided. In contrast, the suction unit <NUM> may not be provided in the three-dimensional shaping devices <NUM> and 100c.

(C4) In the three-dimensional shaping device <NUM> and 100c of the embodiments described above, the cooling unit <NUM> is provided inside the barrels <NUM> and 50c. In contrast, the cooling unit <NUM> may be provided outside the barrels <NUM> and 50c. For example, the cooling unit <NUM> may be provided in the vicinity of the outer peripheral portion of the groove forming surface <NUM> of the flat screw <NUM> inside the screw case <NUM>. The cooling unit <NUM> may not be provided in the three-dimensional shaping devices <NUM> and 100c.

(C5) In the three-dimensional shaping devices <NUM> and 100c of the embodiments described above, the refrigerant pipe <NUM> is disposed in the barrel 50c in the cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM> in a manner that the shortest distance between the refrigerant pipe <NUM> and the communication hole <NUM> in the X direction is longer than the shortest distance between the refrigerant pipe <NUM> and the outer peripheral edge of the groove forming surface <NUM> in the X direction which is the direction perpendicular to the central axis RX of the flat screw <NUM>. In contrast, the refrigerant pipe <NUM> is disposed in the cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM> in a manner that the shortest distance between the refrigerant pipe <NUM> and the communication hole <NUM> in a direction perpendicular to the central axis RX of the flat screw <NUM> is longer than the shortest distance between the refrigerant pipe <NUM> and the outer peripheral edge of the groove forming surface <NUM> in the direction perpendicular to the central axis RX of the flat screw <NUM>. For example, the refrigerant pipe <NUM> is disposed in the barrel 50c in the cross section passing through the central axis RX of the flat screw <NUM> and perpendicular to the central axis AX1 of the valve portion <NUM> in a manner that the shortest distance between the refrigerant pipe <NUM> and the communication hole <NUM> in X direction is the same as the shortest distance between the refrigerant pipe <NUM> and the outer peripheral edge of the groove forming surface <NUM> in the X direction.

(C6) In the three-dimensional shaping devices <NUM> and 100c of the embodiments described above, the melting units <NUM> and 30c include the flat screw <NUM> having a flat cylindrical shape and respective barrels <NUM> and 50c each having the flat screw <NUM> facing surface. In contrast, the melting units <NUM> and 30c may include an in-line screw having an elongated axial outer shape and a spiral groove formed on the side surface of an axis, and a barrel having a cylindrical screw facing surface.

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. For example, the present disclosure can be implemented by the following forms. In order to solve some or all of the problems described in the present disclosure, or to achieve some or all of the effects of the present disclosure, technical features of the embodiments described above corresponding to technical features to be described below of the embodiments can be replaced or combined as appropriate. In addition, unless described as essential herein, the technical features can be deleted as appropriate.

According to the three-dimensional shaping device of the aspect, it is possible to suction the shaping material in the communication hole between the discharge amount adjustment mechanism and the nozzle by the suction unit. Therefore, when the supply of the shaping material to the nozzle is stopped by the discharge amount adjustment mechanism, the discharge of the shaping material from the nozzle can be stopped more quickly.

Claim 1:
A three-dimensional shaping device comprising:
a melting unit (<NUM>) configured to melt a material into a shaping material; and
a nozzle (<NUM>) configured to discharge the shaping material supplied from the melting unit (<NUM>) toward a stage (<NUM>), wherein
the melting unit (<NUM>) includes
a flat screw (<NUM>) configured to rotate about a rotation axis (RX) and having a groove forming surface (<NUM>) in which a groove to which the material is supplied is formed;
a heating unit (<NUM>) configured to heat the material supplied to the groove;
a barrel (<NUM>) having a facing surface (<NUM>) that faces the groove forming surface (<NUM>) and provided with a communication hole (<NUM>) that communicates the facing surface (<NUM>) with the nozzle (<NUM>);
a discharge amount adjustment mechanism (<NUM>) provided in the communication hole (<NUM>) and configured to adjust a flow rate of the shaping material discharged from the nozzle (<NUM>);
the heating unit (<NUM>) is disposed in the barrel (<NUM>), and a shortest distance between the heating unit (<NUM>) and the communication hole (<NUM>) of the barrel (<NUM>) is shorter than a shortest distance between the heating unit (<NUM>) and an outer peripheral edge of the flat screw (<NUM>) in a direction perpendicular to the rotation axis of the flat screw (<NUM>),
characterized in that
the three dimensional shaping device further includes a cooling unit (<NUM>), and a shortest distance between the cooling unit (<NUM>) and the communication hole (<NUM>) of the barrel (<NUM>) is longer than a shortest distance between the cooling unit (<NUM>) and the outer peripheral edge of the flat screw (<NUM>) in the direction perpendicular to the rotation axis (RX) of the flat screw (<NUM>).