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

Abstract

The invention provides a material supply device, an injection molding device and a three-dimensional modeling device, which can restrain back flow of molten resin between a cylinder and a plunger. This material supply device is provided with an injection unit that has: a cylinder that communicates with a nozzle and is connected to a flow path through which a plasticized material flows; and a plunger that moves within the cylinder, in which: a suction operation is performed in which the plasticized material is sucked into the cylinder from the flow path by moving the plunger rearward; and a delivery operation of delivering the plasticized material sucked into the cylinder to the nozzle by moving the plunger forward, the plunger having, in the longitudinal direction of the plunger, a second portion made of a material containing a metal and at least one first portion made of a material containing a resin, the first portion being made of a material containing a metal, the second portion being made of a material containing a resin, and the first portion being made of a material containing a resin. 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 is moved to the rearmost in a suction operation.

Description

Technical Field

[0001] The invention relates to a material supply device, an injection molding device and a three-dimensional modeling device. Background Art

[0002] Patent Document 1 discloses an injection molding device that ejects molten resin in an injection cylinder using an injection plunger to inject molten resin into a mold cavity.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-157601

[0004] When the molten resin in the cylinder is ejected by a plunger, a technology is required to suppress the backflow of the molten resin between the cylinder and the plunger. Summary of the Invention

[0005] According to a first aspect of the present invention, a material supply device is provided. The material supply device includes: a plasticizing section that plasticizes at least a portion of a material to produce a plasticized material; a nozzle that ejects the plasticized material; and an ejection section having a cylinder and a plunger, the cylinder communicating with the nozzle and connected to a flow path through which the plasticized material flows. The plunger moves within the cylinder, and the ejection section performs a suction operation and a delivery operation. During the suction operation, the plunger is moved rearward, away from the flow path, to suck the plasticized material from the flow path into the cylinder. During the delivery operation, the plunger is moved forward, in a direction opposite to the first direction, to deliver the plasticized material sucked into the cylinder toward the nozzle. The plunger has a second portion and at least one first portion along the length of the plunger, the first portion being composed of a material containing metal, and the second portion being composed of a material containing resin. The gap between the second portion and the cylinder is smaller than the gap between the first portion and the cylinder. During the suction operation, when the plunger moves to its rearmost position, the second portion is located within the cylinder.

[0006] According to a second aspect of the present invention, there is provided an injection molding device comprising: the material supply device; and a mold clamping device for opening and closing a molding die into which the plasticized material is injected from the nozzle.

[0007] According to a third aspect of the present invention, there is provided a three-dimensional modeling apparatus comprising: the material supply device described above; and a stage for accumulating the plasticized material ejected from the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a plan view showing a schematic structure of an injection molding device.

[0009] Figure 2 It is a perspective view showing a schematic structure of an injection molding device.

[0010] Figure 3 It is a cross-sectional view showing a schematic structure of a material supply device.

[0011] Figure 4 It is a perspective view showing the schematic structure of a flat head screw.

[0012] Figure 5 It is a brief top view of the barrel.

[0013] Figure 6 It is a three-dimensional diagram of the plunger.

[0014] Figure 7 This is an exploded perspective view of the plunger.

[0015] Figure 8 It is a schematic diagram showing a state where a plunger moves in a cylinder.

[0016] Figure 9 It is a diagram showing the discharge path of waste materials.

[0017] Figure 10 It is a schematic diagram showing the schematic structure of a three-dimensional modeling device.

[0018] Description of Reference Numerals

[0019] 10…Injection molding device; 30…Hopper; 100…Material supply device; 101…Storage unit; 110…Plasticizing unit; 111…Flat-head screw; 112…Barrel; 113…Heater; 114…Nozzle; 115…Communication hole; 116…Flow path; 118…Motor; 119…Drive shaft; 120…Injection unit; 121…Cylinder; 122…Plunger; 123…Plunger drive unit; 124…Check valve; 125…Discharge port; 126…Ball screw; 127…Motor; 130…Mold clamping device; 131…Mold drive unit; 132…Ball screw; 150…Guide member; 151 …inclined surface; 160…molding 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…cutout portion; 177…small diameter portion; 178…external thread portion; 201…groove forming surface; 202…groove; 203…material inlet; 204…ribbed portion; 205…central portion; 211…guide groove; 212…opposing surface; 400…three-dimensional molding device; 410…stage; 420…moving mechanism; 430…valve; 450…control unit; 500…control unit. DETAILED DESCRIPTION

[0020] A. First embodiment:

[0021] Figure 1 It is a plan view showing a schematic structure of the injection molding device 10 according to the first embodiment. Figure 2 1 is a perspective view showing a schematic structure of the injection molding device 10. Figure 1 、 2 : Arrows indicating mutually orthogonal X, Y, and Z directions are shown in FIG. The X and Y directions are directions parallel to the horizontal plane, and the Z direction is a direction opposite to the direction of gravity. Figure 3 The X, Y, and Z directions shown below are Figure 1 、 Figure 2 In the following description, when specifying a direction, the direction indicated by the arrow, i.e., the positive direction, is designated as "+", and the direction opposite to the direction indicated by the arrow, i.e., the negative direction, is designated as "-", and directions are expressed using positive and negative signs.

[0022] The injection molding apparatus 10 includes a material supply device 100, a mold clamping device 130, and a control unit 500. The injection molding apparatus 10 injects plasticized material generated by the material supply device 100 into a molding die 160 to form a molded product. The operations of the material supply device 100 and the mold clamping device 130 are controlled by the control unit 500. The control unit 500 is configured as a computer including a CPU and memory. The CPU executes programs stored in the memory to control various components of the injection molding apparatus 10. Alternatively, the control unit 500 may be configured as an electronic circuit.

[0023] A metal forming mold 160 is mounted on the mold clamping device 130. The forming mold 160 is not limited to metal products, but may also be a resin product or a ceramic product. The metal forming mold 160 is referred to as a metal mold. The forming mold 160 includes a fixed mold 161 and a movable mold 162. The fixed mold 161 is a mold fixed relative to the material supply device 100. The movable mold 162 is a mold that can be moved forward and backward relative to the fixed mold 161 along the mold clamping direction by the mold clamping device 130. In this embodiment, the mold clamping direction is the -Y direction.

[0024] 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 driving unit 131 composed of a motor to rotate the ball screw 132, thereby moving the movable mold 162 connected to the ball screw 132 relative to the fixed mold 161, thereby opening and closing the molding mold 160.

[0025] A hopper 30 is connected to the material supply device 100, into which the material for the molded product is fed. For example, a thermoplastic resin in pellet form is used as the material for the molded product. Examples of thermoplastic resins include ABS (acrylonitrile-butadiene-styrene copolymer), PC (polycarbonate), POM (polyoxymethylene), PP (polypropylene), and PBT (polybutylene terephthalate). In addition to thermoplastic resins, the material for the molded product may also contain metal or ceramic. Material supply to the material supply device 100 is not limited to the hopper 30; for example, it may be supplied via a hose for pressure feeding the material.

[0026] 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 the cavity defined between the fixed mold 161 and the movable mold 162. In this specification, the term "plasticization" encompasses melting and refers to the change from a solid state to a fluid state. Specifically, for materials that undergo a glass transition, plasticization refers to raising the material temperature to above the glass transition point. For materials that do not undergo a glass transition, plasticization refers to raising the material temperature to above the melting point.

[0027] Figure 3 1 is a cross-sectional view schematically illustrating the structure of the material supply device 100. The material supply device 100 includes a plasticizing unit 110 for plasticizing at least a portion of the material to generate a plasticized material, a nozzle 114 for injecting the plasticized material, and an injecting unit 120 communicating with the nozzle 114.

[0028] The plasticizing section 110 includes a flat screw 111 , a barrel 112 , and a heater 113 serving as a heating section.

[0029] The flat-head screw 111 is housed in the housing portion 101. The flat-head screw 111 is called a rotor, or simply a screw. The flat-head screw 111 is rotated in the housing portion 101 by the motor 118, with the drive shaft 119 of the motor 118 as the center. The center axis RX, which serves as the rotation center of the flat-head screw 111, coincides with the center of the drive shaft 119 of the motor 118 on the XZ plane. In this embodiment, the axial direction of the drive shaft 119 and the center axis RX is along the Y direction. The rotation of the flat-head screw 111 based on the motor 118 is controlled by the control unit 500. In addition, the flat-head screw 111 can also be driven by the motor 118 via a reducer.

[0030] A communication hole 115 is formed in the center of the barrel 112. Communication hole 115 communicates with a flow path 116. A cylinder 121 and nozzle 114, described below, are connected to flow path 116. A check valve 124 is provided upstream of cylinder 121 within flow path 116. Check valve 124 prevents backflow of plasticized material from nozzle 114 toward flat-head screw 111.

[0031] The heater 113 heats the barrel 112. The heating of the heater 113 is controlled by the control unit 500. Figure 3 In the embodiment, the heater 113 is arranged on the -Y direction side of the cylinder 121, but the heater 113 may be arranged on the +Z direction side or the -Z direction side of the cylinder 121. Furthermore, a plurality of heaters 113 may be arranged so as to sandwich the cylinder 121 from the +Z direction side and the -Z direction side.

[0032] Figure 4 This is a perspective view showing the schematic structure of the flat-head screw 111. The flat-head screw 111 is generally cylindrical, with the length of the cylindrical shape along the central axis RX being shorter than the length perpendicular to the central axis RX. A spiral groove 202 is formed on the groove-forming surface 201 of the flat-head screw 111, which faces the barrel 112, centered at a central portion 205. The groove 202 communicates with a material inlet 203 formed on the side of the flat-head screw 111. Material supplied from the hopper 30 is fed into the groove 202 through the material inlet 203. The groove 202 is formed by being separated by a ridge 204. Figure 4 The example of forming three grooves 202 is shown, but the number of grooves 202 may be one or more. In addition, the grooves 202 are not limited to being spiral-shaped, but may also be spiral-shaped or involute-shaped, or may be shaped to extend in an arc from the central portion 205 toward the periphery.

[0033] Figure 5 This is a simplified top view of the barrel 112. The barrel 112 has an opposing surface 212 that opposes the groove-forming surface 201 of the flat-head screw 111. A connecting 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 on the opposing surface 212. The plurality of guide grooves 211 are connected to the connecting hole 115 and extend in a spiral shape from the connecting hole 115 toward the periphery. In addition, the guide grooves 211 do not need to be provided in the barrel 112. Furthermore, the guide grooves 211 do not need to be connected to the connecting hole 115.

[0034] The material supplied to groove 202 of flat screw 111 is plasticized between flat screw 111 and barrel 112 by the rotation of flat screw 111 and the heating of heater 113. The material flows along groove 202 and guide groove 211 as flat screw 111 rotates, and is guided toward central portion 205 of flat screw 111. The material flowing into central portion 205 flows out from communication hole 115 provided in the center of barrel 112 to flow path 116.

[0035] like Figure 3As shown, the injection unit 120 includes a cylinder 121 connected to the nozzle 114 and to the flow path 116 through which the plasticized material flows; a plunger 122 that moves within the cylinder 121; and a plunger drive unit 123. The cylinder 121 has a generally cylindrical shape. It is made of, for example, alloy tool steel. For example, SKD11 is used as the alloy tool steel. The cylinder 121 is also called a sleeve. The plunger 122 has a generally cylindrical shape. The plunger drive unit 123 includes a ball screw 126 that moves the plunger 122 along its longitudinal direction; 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 rotates about a central axis along the longitudinal direction of the plunger 122 and moves forward or backward. “Front” refers to a direction in which the plunger 122 approaches the flow path 116 , and “rear” refers to a direction in which the plunger 122 moves away from the flow path 116 .

[0036] In the injection unit 120, the control unit 500 controls the plunger drive unit 123, thereby performing suction and delivery operations. The suction operation refers to the operation of sucking the plasticized material from the flow path 116 into the cylinder 121 by moving the plunger 122 backward. The delivery operation refers to the operation of delivering the plasticized material sucked into the cylinder 121 toward 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 and delivery operations. The suction operation is also called the metering operation.

[0037] Figure 6 This is a perspective view of the plunger 122. The plunger 122 of this embodiment has a first portion 171 and a second portion 172 along the longitudinal direction of the plunger 122. The first portion 171 is made of a material containing metal, and the second portion 172 is made of a material containing resin. The first portion 171 is made of, for example, alloy tool steel, similar to the cylinder 121. As an example of alloy tool steel, SKD11 is used. The second portion 172 is made of, for example, a highly slidable resin. As an example of a highly slidable resin, PEEK (Poly Ether Ether Ketone), PBI (Polybenzimidazole), or PPS (Polyphenylene sulfide) is used. The resin used for the second portion 172 is a resin that is heat-resistant to the molding temperature of the injection molding device 10.

[0038] In this embodiment, the plunger 122 includes two first portions 171 and one second portion 172. More specifically, the plunger 122 is configured such that a single cylindrical second portion 172 is sandwiched between the two first portions 171 along its length. The diameter of the second portion 172 is larger than that of the first portion 171. Hereinafter, the first portion 171 located forward of the second portion 172 is referred to as the front portion 173, and the first portion 171 located rearward of the second portion 172 is referred to as the rear portion 174.

[0039] The front end portion 173 has a roughly conical shape. The rear end portion 174 is formed into a roughly 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 the present embodiment, two flat portions 175 are formed on the side surface of the rear end portion 174, sandwiching 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 called a D-cut portion. The flat portion 175 can be provided not only in the rear end portion 174 but also in the front end portion 173. A cutout portion 176 is provided at the rearmost end of the rear end portion 174, and the cutout portion 176 is provided for a connecting component to be embedded in the connecting component, which is used to connect the plunger 122 and the ball screw 126 provided in the plunger drive portion 123.

[0040] Figure 7 This is an exploded perspective view of the plunger 122. The front end of the rear end portion 174 is provided with a small-diameter portion 177 into which the cylindrical second portion 172 is inserted. The front end of the small-diameter portion 177 is provided with an external threaded portion 178 having a smaller diameter than the small-diameter portion 177. The rear end surface of the front end portion 173 is provided with an internal threaded portion (not shown). With the cylindrical second portion 172 inserted through the small-diameter portion 177 of the rear end portion 174, the internal threaded portion of the front end portion 173 is screwed onto the external threaded portion 178 of the rear end portion 174, thereby assembling the plunger 122. Thus, in this embodiment, the second portion 172 is configured to be attachable to and detachable from the first portion 171.

[0041] Figure 8 1 is a schematic diagram showing the state in which the plunger 122 moves in the cylinder 121. Figure 8 The upper part of FIG shows the state where the plunger 122 moves to the front by the sending operation. Figure 8 The lower section shows the plunger 122 in its rearmost position during the suction 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 in contact with the inner surface of the cylinder 121.

[0042] The cylinder 121 has a discharge hole 125 for discharging waste material from the cylinder 121. When the plunger 122 moves to the rearmost position during suction operation, the discharge hole 125 is located further rearward than the second portion 172. The discharge hole 125 is located below the plunger 122. During the delivery 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 the flat portion 175 on the side of the plunger 122 to scrape it off. When the plunger 122 moves rearward during suction operation, the second portion 172 slides relative to the cylinder 121, pushing the scrap material rearward and discharging it from the discharge hole 125 below the plunger 122 to the exterior of the material supply device 100.

[0043] Figure 9 It is a diagram showing the discharge path of waste materials. Figure 9 This figure shows a cross section of the material supply device 100 as viewed from the nozzle 114 side. The material supply device 100 includes a guide member 150 below the discharge hole 125. The guide member 150 guides the waste material discharged from the discharge hole 125. The guide member 150 has an inclined surface 151. The waste material falling from the discharge hole 125 slides on the inclined surface 151 of the guide member 150 and is then collected in a waste container or the like located outside the material supply device 100.

[0044] The plunger 122 of the material supply device 100 of the first embodiment described above includes a first portion 171 and a second portion 172 along its length. The first portion 171 is formed of a material containing metal, and the second portion 172 is formed 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 plasticized material within 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 making the gap between the cylinder 121 and the second portion 172 substantially zero. Therefore, by forming the second portion 172 of a material containing resin, the gap between the plunger 122 and the cylinder 121 can be effectively reduced. In addition, in this embodiment, the second portion 172 is made of a material containing resin, so the sliding resistance of the plunger 122 can be reduced compared to a case where the plunger 122 is made of the same metal as the cylinder 121. Therefore, it is possible to achieve both reduction in the sliding resistance of the plunger 122 and suppression of backflow.

[0045] 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 within the cylinder 121. Therefore, regardless of the operating state of the plunger 122, the second portion 172 is always located within the cylinder 121. As a result, the plasticized material can be prevented from flowing out of the material supply device 100 through the cylinder 121.

[0046] Furthermore, in this embodiment, the metal-containing first portion 171 is located in front of and behind the resin-containing second portion 172 along the length of the plunger 122. In other words, the second portion 172 is located between the two first portions 171. This makes it easier to ensure the plunger 122's pressure resistance against the pressure from the flow path 116. Furthermore, the length of the second portion 172 that slides relative to the cylinder 121 can be reduced relative to the overall length of the plunger 122, thereby reducing the sliding resistance of the plunger 122 relative to the cylinder 121.

[0047] Furthermore, in this embodiment, the side surface of the first portion 171 of the plunger 122 includes a flat portion 175 extending along the length of the plunger 122. This reduces the sliding resistance between the plunger 122 and the cylinder 121. Furthermore, in this embodiment, the plunger 122 rotates and moves within the cylinder 121, so the flat portion 175 can scrape off any scrap material adhering to the inner surface of the cylinder 121. This prevents the sliding resistance of the plunger 122 relative to the cylinder 121 from increasing as the material supply device 100 is used.

[0048] Furthermore, in this embodiment, the cylinder 121 has a discharge hole 125. When the plunger 122 moves to the rearmost position during suction operation, the discharge hole 125 is located further rearward than the second portion 172. Therefore, waste material between the cylinder 121 and the plunger 122 can be discharged from the discharge hole 125 to the outside of the cylinder 121. Furthermore, the material supply device 100 of this embodiment has a guide member 150 below the discharge hole 125. The guide member 150 guides the waste material discharged from the discharge hole 125. Consequently, the waste material can be appropriately discharged to the outside of the material supply device 100.

[0049] Furthermore, in this embodiment, the second portion 172, which is made of a material containing resin, is detachable from the first portion 171, which is made of a material containing metal. Therefore, even if the second portion 172 is worn out, it can be easily replaced. This improves the maintainability of the material supply device 100.

[0050] B. Second embodiment:

[0051] The material supply device 100 of the first embodiment is provided in the injection molding device 10. However, the material supply device 100 is not limited to the injection molding device 10, and may be provided in, for example, a three-dimensional molding device that injects plasticized material from a nozzle to mold a three-dimensional object.

[0052] Figure 10 4 is a schematic diagram showing a schematic configuration of a three-dimensional modeling apparatus 400. The three-dimensional modeling apparatus 400 includes a material supply device 100, a stage 410, and a moving mechanism 420.

[0053] The material supply device 100 of the second embodiment does not include the one-way valve 124 in the flow path 116, but instead includes a valve 430. The valve 430 switches the amount of plasticized material discharged from the nozzle 114, or whether or not the plasticized material is discharged. The valve 430 is driven under the control of the control unit 450. The rest of the structure of the material supply device 100 is the same as that of the material supply device 100 of the first embodiment.

[0054] 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 moving mechanism 420.

[0055] The moving mechanism 420 changes the relative position of the nozzle 114 and the stage 410. In this embodiment, the moving mechanism 420 changes the relative position of the nozzle 114 and the stage 410 by moving the stage 410. The moving mechanism 420 of this embodiment is composed of a three-axis positioner, which uses power generated by three motors to move the stage 410 along the three axial directions of X, Y, and Z. Each motor is driven under the control of the control unit 450. In addition, the moving mechanism 420 can also be configured to change the relative position of the nozzle 114 and the stage 410 by moving the material supply device 100 without moving the stage 410. Furthermore, the moving mechanism 420 can also be configured to change the relative position of the nozzle 114 and the stage 410 by moving both the stage 410 and the material supply device 100.

[0056] Under the control of the control unit 450, the three-dimensional modeling apparatus 400 ejects plasticized material from the nozzle 114 while changing the relative position between the nozzle 114 and the stage 410. This stacks layers of plasticized material on the stage 410, thereby forming a desired three-dimensional object. When the control unit 450 temporarily stops ejecting plasticized material from the nozzle 114 using the valve 430, it drives the plunger 122 to draw the plasticized material around the nozzle 114 into the cylinder 121. Then, when the valve 430 resumes ejecting plasticized material from the nozzle 114, it drives the plunger 122 to pressurize the plasticized material drawn into the cylinder 121 toward the nozzle 114.

[0057] C. Other implementation methods:

[0058] (C1) In the above embodiment, the first portion 171 is located on both sides of the plunger 122, either in front of or behind the second portion 172, along its longitudinal direction. Alternatively, 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.

[0059] (C2) In the above embodiment, the first portion 171 of the plunger 122 has a flat portion 175 on a portion of its side surface. Alternatively, the first portion 171 may not 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; for example, the flat portion 175 may extend in a direction intersecting the longitudinal direction of the plunger 122.

[0060] (C3) In the above embodiment, the plunger 122 moves in the cylinder 121 while rotating. However, the plunger 122 may move in the cylinder 121 without rotating.

[0061] (C4) In the above embodiment, the cylinder 121 is provided with the discharge hole 125 . However, the cylinder 121 may not be provided with the discharge hole 125 .

[0062] (C5) In the above embodiment, the material supply device 100 includes the guide member 150 , and the guide member 150 guides the scrap discharged from the discharge hole 125 . However, the material supply device 100 may not include the guide member 150 .

[0063] (C6) In the above embodiment, the second portion 172 of the plunger 122 is configured to be attachable to and detachable from the first portion 171. However, the second portion 172 and the first portion 171 may be configured to be inseparable.

[0064] D.Other methods:

[0065] The present invention is not limited to the above-described embodiments and can be implemented in various ways without departing from its main purpose. For example, in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects, the technical features of the embodiments corresponding to the technical features in the various embodiments described below can be appropriately replaced or combined. Furthermore, if the technical features are not described as essential elements in this specification, they can be appropriately deleted.

[0066] (1) According to a first aspect of the present invention, a material supply device is provided. The material supply device includes: a plasticizing section for plasticizing at least a portion of a material to produce a plasticized material; a nozzle for injecting the plasticized material; and an injecting section including a cylinder and a plunger. The cylinder is communicated with the nozzle and is connected to a flow path through which the plasticized material flows. The plunger moves within the cylinder. The injecting section performs a suction operation and a delivery operation. During the suction operation, the plunger is moved in a direction away from the flow path, i.e., rearward, to suck the plasticized material from the flow path into the cylinder. During the delivery operation, the plunger is moved in a direction toward the flow path, i.e., forward, to deliver the plasticized material sucked into the cylinder toward the nozzle. The plunger has a second portion and at least one first portion along its longitudinal direction. The first portion is formed of a material containing metal, and the second portion is formed of a material containing resin. The gap between the second portion and the cylinder is smaller than the gap between the first portion and the cylinder. During the suction operation, when the plunger moves to the rearmost position, the second portion is located within the cylinder.

[0067] According to this type of material supply device, it is possible to suppress the backflow of the plasticized material between the cylinder and the plunger.

[0068] (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 plunger's pressure resistance against pressure from the flow path.

[0069] (3) In the above aspect, the first portion may have a flat portion on a side surface of the first portion facing the inner surface of the cylinder. According to this aspect, the sliding resistance between the plunger and the cylinder can be reduced.

[0070] (4) In the above embodiment, the flat portion may extend along the longitudinal direction. According to such an embodiment, the sliding resistance between the plunger and the cylinder can be reduced.

[0071] (5) In the above embodiment, the plunger may be rotated about a central axis along the longitudinal direction and moved within the cylinder. According to this embodiment, waste material adhering to the inner surface of the cylinder can be scraped off by the flat portion.

[0072] (6) In the above embodiment, the cylinder may have a discharge hole, and when the plunger moves to the rearmost position during the suction operation, the discharge hole may be located further rearward than the second portion. According to this embodiment, waste material between the cylinder and the plunger can be discharged from the cylinder through the discharge hole.

[0073] (7) In the above embodiment, a guide member may be provided below the discharge hole to guide the waste discharged from the discharge hole. According to this embodiment, the waste can be appropriately discharged to the outside of the material supply device.

[0074] (8) In the above embodiment, the second part may be configured to be attachable to and detachable from the first part. According to this embodiment, even when the second part is worn out, the second part can be easily replaced.

[0075] (9) According to a second aspect of the present invention, there is provided an injection molding device comprising: the material supply device; and a mold clamping device for opening and closing a molding die into which the plasticized material is injected from the nozzle.

[0076] (10) According to a third aspect of the present invention, there is provided a three-dimensional modeling apparatus comprising: the material supply device; and a stage for accumulating the plasticized material ejected from the nozzle.

Claims

1. A material supply device, characterized in that: have: a plasticizing portion for plasticizing at least a portion of the material to generate a plasticized material; a nozzle for ejecting the plasticized material; and The ejection unit includes a cylinder and a plunger. The cylinder is connected to the nozzle and is connected to a flow path for the plasticized material to flow. The plunger moves within the cylinder to perform a suction operation and a delivery operation in the ejection unit. During the suction operation, the plunger is moved in a direction away from the flow path, i.e., rearward, to suck the plasticized material from the flow path into the cylinder. During the delivery operation, the plunger is moved in a direction toward the flow path, i.e., forward, to deliver the plasticized material sucked into the cylinder toward the nozzle. The plunger has a second portion and at least one first portion in the longitudinal direction of the plunger, the first portion being made of a material containing metal, and the second portion being made of a material containing resin. The gap between the second portion and the cylinder is smaller than the gap between the first portion and the cylinder, In the suction operation, when the plunger moves to the rearmost position, the second portion is located within the cylinder.

2. The material supply device according to claim 1, characterized in that The plunger has two first parts, In the length direction, the second portion is located between the two first portions.

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

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

5. The material supply device according to claim 3, characterized in that: The plunger rotates about a central axis along the longitudinal direction and moves within the cylinder.

6. The material supply device according to claim 1, characterized in that The cylinder has a discharge hole positioned rearward of the second portion when the plunger moves rearward in the suction operation.

7. The material supply device according to claim 6, characterized in that: A guide member is provided below the discharge hole to guide the waste discharged from the discharge hole.

8. The material supply device according to claim 1, characterized in that The second portion is configured to be attachable to and detachable from the first portion.

9. An injection molding device, characterized in that: have: The material supply device according to claim 1; and The mold clamping device opens and closes the molding die, and the molding die is ejected with the plasticized material from the nozzle.

10. A three-dimensional modeling device, characterized in that: have: The material supply device according to claim 1; and A loading platform is used to accumulate the plasticized material ejected from the nozzle.

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