Material supply device, injection molding device, and three-dimensional modeling device

Abstract

To provide a technology capable of suppressing backflow of a molten resin between a cylinder and a plunger.SOLUTION: A material supply device comprises an injection unit that is communicated with a nozzle, has a cylinder connected to a flow path through which a plasticized material flows and a plunger moving within the cylinder, and executes: a suction operation of sucking the plasticized material into the cylinder from the flow path by moving the plunger backward; and a delivery operation of delivering the plasticized material sucked into the cylinder to the nozzle by moving the plunger forward.The plunger has, in a longitudinal direction of the plunger, at least one first portion made of a material containing metal and a second portion made of a material containing resin, a gap between the second portion and the cylinder is smaller than a gap between the first portion and the cylinder, and in the suction operation, when the plunger is moved to a rearmost position thereof, the second portion is located within the cylinder.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a material supplying device, an injection molding device, and a three-dimensional modeling device. [Background technology]

[0002] Patent Document 1 discloses an injection molding device in which molten resin in an injection cylinder is pushed out by an injection plunger to be injected into a cavity of a mold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-157601 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a technology that can prevent the molten resin from flowing back between the cylinder and the plunger when the molten resin in the cylinder is pushed out by the plunger. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a material supplying device comprising: a plasticizing unit that plasticizes at least a portion of a material to produce a plasticized material; a nozzle that injects the plasticized material; a cylinder that communicates with the nozzle and is connected to a flow path through which the plasticized material flows; and an injection unit that has a plunger that moves within the cylinder, and that performs a suction operation of sucking the plasticized material from the flow path into the cylinder by moving the plunger backward, i.e., away from the flow path, and a delivery operation of delivering the plasticized material sucked into the cylinder to the nozzle by moving the plunger forward, i.e., in a direction opposite to the first direction, the plunger has at least one first portion made of a material containing metal and a second portion made of a material containing resin, in a longitudinal direction of the plunger, a gap between the second portion and the cylinder is smaller than the gap between the first portion and the cylinder, and the second portion is located within the cylinder when the plunger moves to the rearmost position during the suction operation.

[0006] According to a second aspect of the present disclosure, there is provided an injection molding apparatus including the material supply device and a mold clamping device that opens and closes a mold into which the plasticized material is injected from the nozzle.

[0007] According to a third aspect of the present disclosure, there is provided a three-dimensional modeling apparatus including the material supply device described above and a stage on which the plasticized material ejected from the nozzle is deposited. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a top view showing a schematic configuration of an injection molding device. [Figure 2] FIG. 1 is a perspective view showing a schematic configuration of an injection molding device. [Figure 3] FIG. 2 is a cross-sectional view showing a schematic configuration of a material supply device. [Figure 4] FIG. 2 is a perspective view showing a schematic configuration of a flat screw. [Figure 5] FIG. 2 is a schematic plan view of the barrel. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 10 is an explanatory diagram showing how a plunger moves inside a cylinder. [Figure 9] FIG. 10 is a diagram showing a discharge path of waste material. [Figure 10] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a three-dimensional modeling apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. First embodiment: FIG. 1 is a top view showing a schematic configuration of an injection molding apparatus 10 in a first embodiment. FIG. 2 is a perspective view showing a schematic configuration of the injection molding apparatus 10. FIGS. 1 and 2 show arrows indicating mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to a horizontal plane, and the Z direction is opposite to the direction of gravity. The X, Y, and Z directions shown in FIG. 3 and subsequent figures correspond to the X, Y, and Z directions shown in FIGS. 1 and 2. In the following description, when specifying a direction, positive and negative signs are used in combination to indicate the direction indicated by the arrow, with "+" indicating the positive direction and "-" indicating the negative direction opposite to the direction indicated by the arrow.

[0010] The injection molding apparatus 10 comprises a material supplying apparatus 100, a mold clamping apparatus 130, and a control unit 500. The injection molding apparatus 10 injects plasticized material produced by the material supplying apparatus 100 into a molding die 160 to form a molded product. The operation of the material supplying apparatus 100 and the mold clamping apparatus 130 is controlled by the control unit 500. The control unit 500 is configured as a computer equipped with a CPU and memory, and controls each part of the injection molding apparatus 10 by the CPU executing a program stored in the memory. Note that the control unit 500 may also be configured as a circuit.

[0011] A metal forming die 160 is attached to the mold clamping device 130. The forming die 160 is not limited to being made of metal, and may be made of resin or ceramic. The metal forming die 160 is called a mold. The forming die 160 includes a fixed die 161 and a movable die 162. The fixed die 161 is a die that is fixed relative to the material supply device 100. The movable die 162 is a die that can be moved forward and backward in the mold clamping direction relative to the fixed die 161 by the mold clamping device 130. In this embodiment, the mold clamping direction is the -Y direction.

[0012] The mold clamping device 130 has the function of opening and closing the fixed mold 161 and the movable mold 162. Under the control of the control unit 500, the mold clamping device 130 drives the mold drive unit 131 formed by a motor to rotate the ball screw 132, and moves the movable mold 162 connected to the ball screw 132 relative to the fixed mold 161, thereby opening and closing the casting mold 160.

[0013] A hopper 30 into which the material for the molded product is fed is connected to the material supply device 100. For example, a thermoplastic resin formed into pellets is used as the material for the molded product. Examples of the thermoplastic resin that can be used include ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyacetal), PP (polypropylene), and PBT (polybutylene terephthalate). The material for the molded product may contain metal or ceramic in addition to the thermoplastic resin. The material may be supplied to the material supply device 100 not only through the hopper 30 but also through a tube through which the material is pressure-fed, for example.

[0014] The material supply device 100 plasticizes at least a portion of the material supplied from the hopper 30 to produce a plasticized material, and then injects the produced plasticized material into a cavity defined between the fixed mold 161 and the movable mold 162. In this specification, "plasticization" is a concept that includes melting, and refers to changing a material from a solid to a fluid state. Specifically, for a material that undergoes glass transition, plasticization refers to raising the temperature of the material to or above the glass transition point. For a material that does not undergo glass transition, plasticization refers to raising the temperature of the material to or above the melting point.

[0015] 3 is a cross-sectional view showing a schematic configuration of material supplying apparatus 100. Material supplying apparatus 100 includes a plasticizing unit 110 that plasticizes at least a portion of a material to produce a plasticized material, a nozzle 114 that injects the plasticized material, and an injecting unit 120 that communicates with nozzle 114.

[0016] The apparatus includes a plasticizing section 110, a flat screw 111, a barrel 112, and a heater 113 as a heating section.

[0017] The flat screw 111 is accommodated in the accommodation unit 101. The flat screw 111 is also called a rotor or simply a screw. The flat screw 111 is rotated by a motor 118 around a drive shaft 119 of the motor 118 within the accommodation unit 101. A central axis RX, which is the rotation center of the flat screw 111, coincides with the center of the drive shaft 119 of the motor 118 in the XZ plane. In this embodiment, the axial directions of the drive shaft 119 and the central axis RX are aligned along the Y direction. The rotation of the flat screw 111 by the motor 118 is controlled by the control unit 500. The flat screw 111 may be driven by the motor 118 via a reducer.

[0018] A communication hole 115 is formed in the center of the barrel 112. The communication hole 115 is connected to a flow path 116. A cylinder 121 and a nozzle 114, which will be described later, are connected to the flow path 116. A check valve 124 is provided in the flow path 116, upstream of the cylinder 121. The check valve 124 prevents the plasticized material from flowing back from the nozzle 114 toward the flat screw 111.

[0019] The heater 113 heats the barrel 112. Heating by the heater 113 is controlled by the control unit 500. In FIG. 3, the heater 113 is arranged on the −Y direction side of the cylinder 121, but the heater 113 may also be arranged on the +Z direction side or the −Z direction side of the cylinder 121. Furthermore, multiple heaters 113 may be arranged to sandwich the cylinder 121 from the +Z direction side and the −Z direction side.

[0020] FIG. 4 is a perspective view showing a schematic configuration of the flat screw 111. The flat screw 111 has a generally cylindrical shape whose length along the central axis RX is shorter than its length perpendicular to the central axis RX. A spiral groove 202 is formed around a central portion 205 on a groove-forming surface 201 of the flat screw 111 facing the barrel 112. The groove 202 communicates with a material inlet 203 formed on the side surface of the flat screw 111. Material supplied from the hopper 30 is supplied to the groove 202 through the material inlet 203. The grooves 202 are formed by being separated by ridge portions 204. FIG. 4 shows an example in which three grooves 202 are formed, but the number of grooves 202 may be one or more. The groove 202 is not limited to a spiral shape, but may also be a spiral shape or an involute curve shape, or may have a shape extending in an arc from the central portion 205 to the outer periphery.

[0021] 5 is a schematic plan view of the barrel 112. The barrel 112 has an opposing surface 212 that faces the groove-forming surface 201 of the flat screw 111. A communication hole 115 that communicates with the flow path 116 is formed in the center of the opposing surface 212. A plurality of guide grooves 211 are formed in the opposing surface 212, connected to the communication hole 115 and extending in a spiral shape from the communication hole 115 toward the outer periphery. Note that the guide grooves 211 do not necessarily have to be provided in the barrel 112. Furthermore, the guide grooves 211 do not necessarily have to be connected to the communication hole 115.

[0022] The material supplied to the groove 202 of the flat screw 111 is plasticized between the flat screw 111 and the barrel 112 by the rotation of the flat screw 111 and the heating of the heater 113, and flows along the groove 202 and the guide groove 211 by the rotation of the flat screw 111, and is guided to the center portion 205 of the flat screw 111. The material that has flowed into the center portion 205 flows out into the flow path 116 from a communication hole 115 provided in the center of the barrel 112.

[0023] As shown in FIG. 3 , the injection unit 120 includes a cylinder 121 that communicates with the nozzle 114 and is connected to a flow path 116 through which the plasticized material flows, a plunger 122 that moves within the cylinder 121, and a plunger driver 123. The cylinder 121 has a generally cylindrical shape. The cylinder 121 is made of, for example, synthetic tool steel. SKD11 is an example of the synthetic tool steel. The cylinder 121 is also called a sleeve. The plunger 122 has a generally cylindrical shape. The plunger driver 123 includes a ball screw 126 that moves the plunger 122 along the longitudinal direction of the plunger 122 and a motor 127 that drives the ball screw 126. In this embodiment, when the ball screw 126 is driven by the motor 127, the plunger 122 connected to the ball screw 126 moves forward or backward while rotating around a central axis along the longitudinal direction of the plunger 122. "Forward" refers to the direction in which the plunger 122 approaches the flow passage 116. "Rear" refers to the direction in which the plunger 122 moves away from the flow passage 116.

[0024] In the injection unit 120, the control unit 500 controls the plunger drive unit 123 to perform a suction operation and a delivery operation. The suction operation is an operation in which the plasticized material is sucked into the cylinder 121 from the flow path 116 by moving the plunger 122 backward. The delivery operation is an operation in which the plasticized material sucked into the cylinder 121 is delivered to the nozzle 114 by moving the plunger 122 forward. The control unit 500 controls the injection amount, injection speed, and injection pressure of the plasticized material from the nozzle 114 by adjusting the movement amount and movement speed of the plunger 122 during the suction operation and delivery operation. The suction operation is also called a metering operation.

[0025] FIG. 6 is a perspective view of plunger 122. Plunger 122 in this embodiment has, in the longitudinal direction of plunger 122, a first portion 171 made of a material containing metal and a second portion 172 made of a material containing resin. Like cylinder 121, first portion 171 is made of, for example, synthetic tool steel. SKD11, for example, is used as the synthetic tool steel. Second portion 172 is made of, for example, a highly slidable resin. Examples of the highly slidable resin include PEEK (polyether ether ketone), PBI (polybenzimidazole), and PPS (polyphenylene sulfide). The resin used for second portion 172 is a resin that is heat resistant to the molding temperature in injection molding apparatus 10.

[0026] In this embodiment, the plunger 122 includes first portions 171 at two locations and second portion 172 at one location. More specifically, the plunger 122 is configured by arranging one cylindrical second portion 172 so as to be sandwiched between two first portions 171 in the longitudinal direction of the plunger 122. The diameter of the second portion 172 is larger than the diameter of the first portion 171. Hereinafter, the first portion 171 located forward of the second portion 172 will be referred to as the leading end portion 173, and the first portion 171 located rearward of the second portion 172 will be referred to as the rear end portion 174.

[0027] The tip portion 173 has a substantially conical shape. The rear end portion 174 is formed in a substantially cylindrical shape. A flat portion 175 is provided on the side surface of the rear end portion 174 facing the inner surface of the cylinder 121. In this embodiment, two flat portions 175 are formed on the side surface of the rear end portion 174 so as to sandwich the central axis of the plunger 122. Each flat portion 175 extends along the longitudinal direction of the plunger 122. The flat portion 175 is also referred to as a D-cut portion. The flat portion 175 may be provided not only on the rear end portion 174 but also on the tip portion 173. A notch 176 is provided at the rearmost end of the rear end portion 174, into which a connecting member for connecting the plunger 122 to the ball screw 126 provided in the plunger drive unit 123 fits.

[0028] FIG. 7 is an exploded perspective view of plunger 122. A small-diameter portion 177 is provided at the tip of rear end portion 174, into which cylindrical second portion 172 is inserted. A male thread portion 178 having a smaller diameter than small-diameter portion 177 is provided at the tip of small-diameter portion 177. A female thread portion (not shown) is provided on the rear end surface of tip portion 173. The plunger 122 is assembled by inserting cylindrical second portion 172 into small-diameter portion 177 of rear end portion 174 and threading the male thread portion 178 of rear end portion 174 into the female thread portion of tip portion 173. In this manner, in this embodiment, second portion 172 is configured to be detachable from first portion 171.

[0029] FIG. 8 is an explanatory diagram showing how the plunger 122 moves inside the cylinder 121. The upper part of FIG. 8 shows how the plunger 122 has moved to its most forward position during the dispensing operation. The lower part of FIG. 8 shows how the plunger 122 has moved to its most rearward position during the aspirating operation. The diameter of the second portion 172 of the plunger 122 is larger than the diameter of the first portion 171. Therefore, the gap between the second portion 172 and the cylinder 121 is smaller than the gap between the first portion 171 and the cylinder 121. In this embodiment, the gap between the second portion 172 and the cylinder 121 is substantially zero. Therefore, the second portion 172 moves while contacting the inner surface of the cylinder 121.

[0030] The cylinder 121 has a discharge hole 125 for discharging waste material from the cylinder 121. The discharge hole 125 is located rearward of the second portion 172 when the plunger 122 moves to its rearmost position during the suction operation. The discharge hole 125 is located below the plunger 122. During the feeding and suction operations of the plunger 122, the plunger 122 is rotated by the plunger drive unit 123. If waste material adheres to the inner surface of the cylinder 121, the rotation of the plunger 122 causes a flat portion 175 on the side of the plunger 122 to scrape off the waste material. When the plunger 122 moves rearward during the suction operation, the second portion 172 slides against the cylinder 121, pushing the scraped-off waste material rearward, and the scraped-off waste material is discharged from the material supply device 100 through the discharge hole 125 located below the plunger 122.

[0031] Figure 9 is a diagram showing the discharge path of the waste material. Figure 9 is a diagram showing a cross section of the material supply device 100 as seen from the nozzle 114 side. The material supply device 100 is provided with a guide member 150 below the discharge hole 125 that guides the waste material discharged from the discharge hole 125. The guide member 150 has an inclined surface 151. The waste material that falls from the discharge hole 125 slides down the inclined surface 151 of the guide member 150 and is stored in a waste material container or the like arranged outside the material supply device 100.

[0032] The plunger 122 included in the material supply device 100 of the first embodiment described above has, in its longitudinal direction, a first portion 171 made of a material containing metal and a second portion 172 made of a material containing resin. The gap between the second portion 172 and the cylinder 121 is smaller than the gap between the first portion 171 and the cylinder 121. Therefore, the second portion 172 of the plunger 122 can suppress backflow of the plasticized material through the cylinder 121. Generally, the thermal expansion coefficient of resin is greater than that of metal. Therefore, during operation of the material supply device 100, the second portion 172 thermally expands more than the cylinder 121, thereby reducing the gap between the cylinder 121 and the second portion 172 to almost zero. Therefore, by forming the second portion 172 from a material containing resin, the gap between the plunger 122 and the cylinder 121 can be effectively reduced. Furthermore, in this embodiment, since the second portion 172 is made of a material containing resin, the sliding resistance of the plunger 122 can be made smaller than when the plunger 122 is made of the same metal as the cylinder 121. Therefore, it is possible to achieve both a reduction in the sliding resistance of the plunger 122 and suppression of backflow.

[0033] Furthermore, in this embodiment, when the plunger 122 moves to the rearmost position during the suction operation, the second portion 172 of the plunger 122 is located inside the cylinder 121. Therefore, regardless of the operating state of the plunger 122, the second portion 172 is always located inside the cylinder 121. As a result, it is possible to prevent the plasticized material from flowing out of the material supply device 100 through the cylinder 121.

[0034] Furthermore, in this embodiment, the first portion 171 containing metal is located both in front of and behind the second portion 172 containing resin in the longitudinal direction of the plunger 122. In other words, the second portion 172 is located between the two first portions 171. This makes it easy to ensure the pressure resistance of the plunger 122 against the pressure from the flow path 116. Furthermore, since the length of the second portion 172 sliding relative to the cylinder 121 can be made shorter than the overall length of the plunger 122, the sliding resistance of the plunger 122 relative to the cylinder 121 can be reduced.

[0035] Furthermore, in this embodiment, the side surface of the first portion 171 of the plunger 122 has a flat portion 175 extending along the longitudinal direction of the plunger 122. This reduces the sliding resistance between the plunger 122 and the cylinder 121. Moreover, in this embodiment, the plunger 122 moves while rotating inside the cylinder 121, and therefore the flat portion 175 can scrape off waste material adhering to the inner surface of the cylinder 121. This prevents the sliding resistance of the plunger 122 against the cylinder 121 from increasing with use of the material supply device 100.

[0036] Furthermore, in this embodiment, the cylinder 121 is provided with a discharge hole 125 that is located rearward of the second portion 172 when the plunger 122 moves to the rearmost position during the suction operation. Therefore, waste material present between the cylinder 121 and the plunger 122 can be discharged from the cylinder 121 through the discharge hole 125. Moreover, the material supplying device 100 of this embodiment is provided with a guide member 150 below the discharge hole 125 that guides the waste material discharged from the discharge hole 125. Therefore, the waste material can be properly discharged outside the material supplying device 100.

[0037] Furthermore, in this embodiment, second portion 172 made of a material containing resin is configured to be detachable from first portion 171 made of a material containing metal. Therefore, even if second portion 172 is worn out, second portion 172 can be easily replaced. Therefore, the maintainability of material supply device 100 can be improved.

[0038] B. Second embodiment: The material supplying device 100 in the first embodiment is provided in an injection molding device 10. However, the material supplying device 100 is not limited to being provided in an injection molding device 10, and may be provided in, for example, a three-dimensional modeling device that injects a plasticized material from a nozzle to form a three-dimensional model.

[0039] 10 is an explanatory diagram showing a schematic configuration of a three-dimensional modeling apparatus 400. The three-dimensional modeling apparatus 400 includes a material supplying apparatus 100, a stage 410, and a movement mechanism 420.

[0040] The material supply device 100 in the second embodiment is provided with a valve 430 in the flow path 116, instead of a check valve 124, which switches the discharge amount of plasticizing material from the nozzle 114 or whether or not to discharge the plasticizing material. The valve 430 is driven under the control of the control unit 450. The other configurations of the material supply device 100 are the same as those of the material supply device 100 in the first embodiment.

[0041] The stage 410 faces the nozzle 114. The plasticized material ejected from the nozzle 114 is deposited on the stage 410. The stage 410 is supported by a movement mechanism 420.

[0042] The movement mechanism 420 changes the relative position between the nozzle 114 and the stage 410. In this embodiment, the movement mechanism 420 changes the relative position between the nozzle 114 and the stage 410 by moving the stage 410. The movement mechanism 420 in this embodiment is configured with a three-axis positioner that moves the stage 410 in three axial directions, that is, the X, Y, and Z directions, using power generated by three motors. Each motor is driven under the control of the control unit 450. Note that the movement mechanism 420 may be configured to change the relative position between the nozzle 114 and the stage 410 by moving the material supply apparatus 100 without moving the stage 410. Alternatively, the movement mechanism 420 may be configured to change the relative position between the nozzle 114 and the stage 410 by moving both the stage 410 and the material supply apparatus 100.

[0043] Under the control of the control unit 450, the three-dimensional modeling apparatus 400 discharges plasticized material from the nozzle 114 while changing the relative position between the nozzle 114 and the stage 410, thereby stacking layers of plasticized material onto the stage 410 to form a three-dimensional object of a desired shape. When the control unit 450 temporarily stops the discharge of plasticized material from the nozzle 114 using the valve 430, it drives the plunger 122 to suck the plasticized material around the nozzle 114 into the cylinder 121. When the control unit 450 resumes the discharge of plasticized material from the nozzle 114 using the valve 430, it drives the plunger 122 to pressure-feed the plasticized material sucked into the cylinder 121 toward the nozzle 114.

[0044] C. Other Embodiments: (C1) In the above embodiment, the first portion 171 is located both in front of and behind the second portion 172 in the longitudinal direction of the plunger 122. However, for example, the first portion 171 may be located only in front of or behind the second portion 172. Furthermore, the first portion 171 and the second portion 172 may each be provided at two or more locations on the plunger 122.

[0045] (C2) In the above embodiment, the first portion 171 of the plunger 122 has a flat portion 175 on a part of the side surface. In contrast, the first portion 171 does not have to have the flat portion 175. Furthermore, the flat portion 175 is not limited to extending along the longitudinal direction of the plunger 122 in the first portion 171, and may extend in a direction intersecting the longitudinal direction of the plunger 122, for example.

[0046] (C3) In the above embodiment, the plunger 122 rotates while moving within the cylinder 121. In contrast to this, the plunger 122 may move within the cylinder 121 without rotating.

[0047] (C4) In the above embodiment, the cylinder 121 is provided with the discharge hole 125. However, the cylinder 121 does not necessarily have to be provided with the discharge hole 125.

[0048] (C5) In the above embodiment, the material supply device 100 is provided with a guide member 150 that guides the waste material discharged from the discharge hole 125. In contrast, the material supply device 100 does not necessarily have to be provided with the guide member 150.

[0049] (C6) In the above embodiment, the second portion 172 of the plunger 122 is configured to be detachable from the first portion 171. However, the second portion 172 and the first portion 171 may be configured to be inseparable.

[0050] D. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0051] (1) According to a first aspect of the present disclosure, there is provided a material supplying device comprising: a plasticizing unit that plasticizes at least a portion of a material to produce a plasticized material; a nozzle that injects the plasticized material; a cylinder that communicates with the nozzle and is connected to a flow path through which the plasticized material flows; and an injection unit that has a plunger that moves within the cylinder and that performs a suction operation of sucking the plasticized material from the flow path into the cylinder by moving the plunger backward, i.e., away from the flow path; and a delivery operation of delivering the plasticized material sucked into the cylinder to the nozzle by moving the plunger forward, i.e., toward the flow path. The plunger has, in a longitudinal direction of the plunger, at least one first portion made of a material containing metal and a second portion made of a material containing resin, wherein a gap between the second portion and the cylinder is smaller than a gap between the first portion and the cylinder, and the second portion is located within the cylinder when the plunger moves to the rearmost position during the suction operation. With this type of material supply device, it is possible to prevent the plasticized material from flowing back between the cylinder and the plunger.

[0052] (2) In the above embodiment, the plunger may have two first portions, and the second portion may be located between the two first portions in the longitudinal direction. This embodiment makes it easier to ensure the pressure resistance of the plunger against pressure from the flow path.

[0053] (3) In the above embodiment, the first portion may have a flat portion on a side surface of the first portion that faces the inner surface of the cylinder. According to this embodiment, it is possible to reduce sliding resistance between the plunger and the cylinder.

[0054] (4) In the above embodiment, the flat portion may extend along the longitudinal direction. This embodiment can reduce sliding resistance between the plunger and the cylinder.

[0055] (5) In the above embodiment, the plunger may move within the cylinder while rotating about a central axis along the longitudinal direction. According to this embodiment, the flat portion can scrape off waste material adhering to the inner surface of the cylinder.

[0056] (6) In the above embodiment, the cylinder may have a discharge hole that is located rearward of the second portion when the plunger moves to its rearmost position during the suction operation. According to this embodiment, waste material present between the cylinder and the plunger can be discharged out of the cylinder through the discharge hole.

[0057] (7) In the above-described embodiment, a guide member may be provided below the discharge hole to guide the waste material discharged from the discharge hole. According to this embodiment, the waste material can be appropriately discharged to the outside of the material supply device.

[0058] (8) In the above aspect, the second part may be configured to be detachable from the first part. According to this aspect, even if the second part is worn out, the second part can be easily replaced.

[0059] (9) According to a second aspect of the present disclosure, there is provided an injection molding apparatus including the material supply device and a mold clamping device that opens and closes a mold into which the plasticized material is injected from the nozzle.

[0060] (10) According to a third aspect of the present disclosure, there is provided a three-dimensional modeling apparatus including the material supply device described above and a stage on which the plasticized material ejected from the nozzle is deposited. [Explanation of symbols]

[0061] 10...injection molding apparatus, 30...hopper, 100...material supply device, 101...storage section, 110...plasticization section, 111...flat screw, 112...barrel, 113...heater, 114...nozzle, 115...communication hole, 116...flow path, 118...motor, 119...drive shaft, 120...injection section, 121...cylinder, 122...plunger, 123...plunger drive section, 124...check valve, 125...discharge hole, 126...ball screw, 127...motor, 130...mold clamping device, 131...mold drive section, 132...ball screw ji, 150... guide member, 151... inclined surface, 160... forming mold, 161... fixed mold, 162... movable mold, 171... first portion, 172... second portion, 173... front end portion, 174... rear end portion, 175... flat portion, 176... notched portion, 177... small diameter portion, 178... male thread portion, 201... groove forming surface, 202... groove, 203... material inlet, 204... convex rib portion, 205... center portion, 211... guide groove, 212... opposing surface, 400... three-dimensional modeling device, 410... stage, 420... moving mechanism, 430... valve, 450... control unit, 500... control unit

Claims

1. a plasticizing section for plasticizing at least a portion of the material to produce a plasticized material; a nozzle for injecting the plasticized material; an injection unit having a cylinder that communicates with the nozzle and is connected to a flow path through which the plasticized material flows, and a plunger that moves within the cylinder, and which performs a suction operation of sucking the plasticized material from the flow path into the cylinder by moving the plunger backward, that is, in a direction away from the flow path, and a delivery operation of delivering the plasticized material that has been sucked into the cylinder to the nozzle by moving the plunger forward, that is, in a direction approaching the flow path; Equipped with the plunger has, in a longitudinal direction of the plunger, at least one first portion made of a material including a metal and a second portion made of a material including a resin; a gap between the second portion and the cylinder is smaller than a gap between the first portion and the cylinder; During the suction operation, when the plunger moves rearward to its most rearward position, the second portion is located within the cylinder. Material feeding device.

2. The material supply device according to claim 1, The plunger has two first portions; A material supplying device, wherein the second portion is located between two of the first portions in the longitudinal direction.

3. The material supply device according to claim 1, The first portion has a flat portion on a side of the first portion facing the inner surface of the cylinder.

4. The material supply device according to claim 3, The flat portion extends along the longitudinal direction.

5. The material supply device according to claim 3, The plunger moves within the cylinder while rotating around a central axis along the longitudinal direction.

6. The material supply device according to claim 1, The cylinder has a discharge hole that is located rearward of the second portion when the plunger moves to its rearmost position during the suction operation.

7. The material supply device according to claim 6, A material supplying device having a guide member below the discharge hole that guides the waste material discharged from the discharge hole.

8. The material supply device according to claim 1, The material supply device, wherein the second part is configured to be detachable from the first part.

9. The material supply device according to claim 1; a mold clamping device that opens and closes a molding die into which the plasticized material is injected from the nozzle; An injection molding apparatus comprising:

10. The material supply device according to claim 1; a stage on which the plasticized material ejected from the nozzle is deposited; A three-dimensional printing apparatus comprising:

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