Injection molding equipment and injection molding mold

Abstract

To reduce a trouble or a cost in differentiating shapes of molded articles molded by an injection molding device.SOLUTION: An injection molding device includes: a stationary mold; a movable mold opposing the stationary mold; a mold clamp part configured to move the movable mold against the stationary mold; and an injection part configured to inject a molten material into a cavity partitioned by the stationary mold and the movable mold. At least one of the stationary mold and the movable mold includes a flow channel communicating with the cavity, the flow channel flowing a working fluid that compresses and extrudes a molded article inside the cavity.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an injection molding apparatus and a mold for injection molding. [Background technology]

[0002] Patent Document 1 discloses an injection molding apparatus equipped with an ejector device for pushing a molded product out of a movable mold. In this injection molding apparatus, the ejector device is equipped with an ejector pin and an ejection motor, which is a part for moving the ejector pin, and is attached to a movable platen. When the ejection motor is driven, the ejector pin advances into the cavity, and the molded product is pushed out of the movable mold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-157635 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an injection molding apparatus like that described in the above document, when changing the shape of a molded product, it is necessary not only to change the molding die but also to change the parts that move the ejector pins, which results in a lot of work and expense in changing the shape of the molded product. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided an injection molding apparatus. The injection molding apparatus includes a fixed mold, a movable mold facing the fixed mold, a mold clamping section for moving the movable mold relative to the fixed mold, and an injection section for injecting molten material into a cavity defined by the fixed mold and the movable mold. At least one of the fixed mold and the movable mold is formed with a flow path communicating with the cavity, through which a working fluid flows to pressurize and extrude a molded product in the cavity.

[0006] According to a second aspect of the present disclosure, there is provided a mold for injection molding. The mold includes a fixed mold and a movable mold that faces the fixed mold and moves relative to the fixed mold. The fixed mold and the movable mold define a cavity to be filled with a molten material, and at least one of the fixed mold and the movable mold is formed with a plurality of flow paths that communicate with the cavity, through which a working fluid flows to pressurize and extrude a molded product in the cavity. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view showing a schematic configuration of an injection molding apparatus according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a schematic configuration of an injection molding apparatus according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view showing a schematic configuration of a flat screw. [Figure 4] FIG. 2 is a plan view showing a schematic configuration of a barrel. [Diagram 5] FIG. 1 is a cross-sectional view showing a schematic configuration of a molding die according to a first embodiment. [Figure 6] FIG. 2 is a plan view showing a schematic configuration of a movable mold according to the first embodiment. [Figure 7] FIG. 1 is a first explanatory diagram showing how a molded product is extruded. [Figure 8] FIG. 2 is a second explanatory diagram showing how the molded product is extruded. [Figure 9] FIG. 3 is a third explanatory diagram showing how the molded product is extruded. [Figure 10]FIG. 6 is a front view showing a schematic configuration of an injection molding apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. First embodiment: FIG. 1 is a front view showing a schematic configuration of an injection molding apparatus 10 in the first embodiment. FIG. 1 shows 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. 2 and subsequent figures correspond to the X, Y, and Z directions shown in FIG. 1. In the following description, when specifying a direction, positive and negative signs are used in combination to indicate the direction, with the positive direction indicated by the arrow being "+" and the negative direction opposite to the direction indicated by the arrow being "-".

[0009] The injection molding apparatus 10 includes an injection unit 100, a clamping unit 200, a molding die 300, and a control unit 500. In this embodiment, the injection unit 100, the clamping unit 200, and the control unit 500 are fixed to a base 20. The molding die 300 is attached to the clamping unit 200.

[0010] A hopper 101 into which molding material, which is the material of the molded product, is charged is connected to the injection unit 100. As the molding material, for example, a thermoplastic resin formed into pellets is used. The molding material is processed into, for example, a pellet shape.

[0011] The injection section 100 plasticizes at least a part of the molding material supplied from the hopper 101 to generate a molten material, and injects the molten material into the mold 300. "Plasticization" means that the molding material having thermoplasticity is melted by applying heat. In addition, "melting" means not only that the molding material having thermoplasticity is heated to a temperature above its melting point and becomes liquid, but also that the molding material having thermoplasticity is heated to a temperature above its glass transition point and softens to develop fluidity. The molten material injected into the mold 300 cools and solidifies inside the mold 300 to become a molded product.

[0012] The control unit 500 is configured by a computer equipped with one or more processors, a main storage device, and an input / output interface for inputting and outputting signals from and to the outside. The control unit 500 controls the injection unit 100 and the mold clamping unit 200 by the processor reading and executing a program on the main storage device, thereby manufacturing a molded product.

[0013] Fig. 2 is a cross-sectional view showing a schematic configuration of the injection molding apparatus 10. Fig. 2 shows cross sections of the injection section 100, the mold clamping section 200, and the molding die 300. The injection section 100 includes a plasticizing section 110, an injection control mechanism 120, and a nozzle 130.

[0014] The plasticizing unit 110 has a function of plasticizing at least a part of the pellet-like molding material supplied from the hopper 101, generating a paste-like molten material having fluidity, and supplying the molten material to the injection control mechanism 120. In this embodiment, the plasticizing unit 110 includes a screw driving unit 111, a screw case 113, a flat screw 115, a barrel 116, and a plasticizing heater 117.

[0015] The screw driving unit 111 is configured with a motor and a reducer. The screw driving unit 111 is driven under the control of the control unit 500. The screw driving unit 111 is connected to the flat screw 115.

[0016] The flat screw 115 is housed in a space surrounded by the screw case 113 and the barrel 116. The flat screw 115 housed in the space is rotated by a rotational driving force from the screw driving unit 111.

[0017] A communication hole 118 penetrating the barrel 116 is provided in the center of the barrel 116. An injection cylinder 121 (described later) is connected to the communication hole 118. A check valve 124 is provided in the communication hole 118 upstream of the injection cylinder 121.

[0018] The plasticizing heater 117 is embedded in the barrel 116. The plasticizing heater 117 generates heat when supplied with power. The temperature of the plasticizing heater 117 is controlled by the control unit 500.

[0019] FIG. 3 is a perspective view showing a schematic configuration of the flat screw 115. The flat screw 115 has a substantially cylindrical shape. The height of the flat screw 115 in the direction along the central axis RX is smaller than the diameter of the flat screw 115. The flat screw 115 has a groove forming surface 150 facing the barrel 116. A groove 152 extending in a spiral shape centered on a central portion 151 is formed in the groove forming surface 150. The groove 152 communicates with a material inlet 153 formed on the side surface of the flat screw 115. The molding material supplied from the hopper 101 is introduced from the material inlet 153 to the groove 152. In this embodiment, three grooves 152 are formed in the groove forming surface 150. The grooves 152 are separated from each other by a convex portion 154. The number of grooves 152 is not limited to three, and may be one, two, or four or more. The shape of the groove 152 is not limited to a spiral shape, but may be a helical or involute curve shape, or may be an arc shape from the center portion 151 to the outer periphery.

[0020] 4 is a plan view showing a schematic configuration of the barrel 116. The barrel 116 has an opposing surface 160 that faces the groove forming surface 150 of the flat screw 115. A communication hole 118 is provided in the center of the opposing surface 160. The communication hole 118 is provided on an extension line of the central axis RX of the flat screw 115. The opposing surface 160 is provided with a plurality of guide grooves 161 that are connected to the communication hole 118 and extend in a spiral shape from the communication hole 118 toward the outer periphery. The guide grooves 161 provided in the opposing surface 160 do not have to be connected to the communication hole 118. Moreover, the opposing surface 160 does not have to have the guide grooves 161 provided therein.

[0021] The molding material supplied to the groove 152 of the flat screw 115 is plasticized between the flat screw 115 and the barrel 116 by the rotation of the flat screw 115 and the heat from the plasticizing heater 117, and flows along the groove 152 and the guide groove 161 by the rotation of the flat screw 115, and is guided to the center portion 151 of the flat screw 115. The molten material that has flowed into the center portion 151 is guided to the injection control mechanism 120 from the communication hole 118.

[0022] 2, the injection control mechanism 120 includes an injection cylinder 121, a plunger 122, and a plunger driver 123. The injection control mechanism 120 has a function of injecting the molten material supplied from the plasticizing section 110 into the injection cylinder 121 from a nozzle 130. The molten material injected from the nozzle 130 is filled into a cavity Cv of a molding die 300, which will be described later.

[0023] The injection cylinder 121 is a substantially cylindrical member connected to the communication hole 118 of the barrel 116, and includes a plunger 122 therein. The plunger 122 slides inside the injection cylinder 121 by a plunger drive unit 123 configured by a motor, and pressure-feeds the molten material in the injection cylinder 121 to the nozzle 130. The plunger drive unit 123 is driven under the control of the control unit 500.

[0024] The molding die 300 has a fixed die 310 and a movable die 320 arranged opposite to the fixed die 310. The fixed die 310 and the movable die 320 come into contact with each other to define a cavity Cv between the fixed die 310 and the movable die 320. The cavity Cv is a space having a shape corresponding to the shape of the molded product. Molten material is injected into the cavity Cv from the nozzle 130. The molten material filled in the cavity Cv cools and solidifies to become a molded product. In this embodiment, the molding die 300 is provided with a guide pin 305 for suppressing misalignment of the movable die 320 with respect to the fixed die 310. The guide pin 305 may not be provided.

[0025] The mold clamping unit 200 has a function of moving the movable mold 320 relative to the fixed mold 310, that is, a function of opening and closing the casting mold 300. In this embodiment, the mold clamping unit 200 includes a fixed platen 210, a movable platen 220, tie bars 230, a ball screw unit 240, and a mold driving unit 250.

[0026] The injection unit 100, the fixed platen 210, and the movable platen 220 are arranged in this order along the X direction. The fixed platen 210 is fixed to the tip of a tie bar 230 provided along the X direction. A fixed mold 310 is fixed to the surface of the fixed platen 210 facing the movable platen 220 by, for example, a bolt or a clamp.

[0027] The movable platen 220 is configured to be movable along tie bars 230. The movable platen 220 is connected to a ball screw unit 240 provided along the X direction. A movable mold 320 is fixed to the surface of the movable platen 220 on the fixed platen 210 side by, for example, a bolt or a clamp.

[0028] The mold driving unit 250 is composed of a motor and a reducer. The mold driving unit 250 is driven under the control of the control unit 500. The mold driving unit 250 is connected to the movable mold 320 via the ball screw unit 240. The mold driving unit 250 rotates the ball screw unit 240 to move the movable mold 320 fixed to the movable platen 220 relative to the fixed mold 310 fixed to the fixed platen 210, thereby opening and closing the forming mold 300.

[0029] Fig. 5 is a cross-sectional view showing a schematic configuration of molding die 300. Fig. 6 is a plan view showing a schematic configuration of movable die 320. Fig. 5 shows molding die 300 in a clamped state. In this embodiment, molding die 300 has fixed die 310, movable die 320, and pressure unit 340.

[0030] In this embodiment, the movable mold 320 has a nesting portion 321 and a storage portion 322. The storage portion 322 is configured in a cylindrical shape. The nesting portion 321 is stored inside the storage portion 322. The nesting portion 321 has a recess 325 on a surface facing the fixed mold 310. When the fixed mold 310 and the nesting portion 321 come into contact with each other, a cavity Cv is defined by the fixed mold 310 and the recess 325. The fixed mold 310 is provided with a through hole into which the nozzle 130 is inserted, and the molten material is injected from the nozzle 130 into the cavity Cv.

[0031] The nested portion 321 has a plurality of flow paths 330 communicating with the cavity Cv. In this embodiment, as shown in FIG. 6, 16 flow paths 330 are provided in the nested portion 321. As shown in FIG. 5, each flow path 330 penetrates the nested portion 321 along the X direction. The opening shape of each flow path 330 is circular. The opening of each flow path 330 on the cavity Cv side is provided with a size that can suppress the inflow of the molten material injected into the cavity Cv into the flow path 330. In this embodiment, the diameter of the opening of each flow path 330 on the cavity Cv side is several micrometers to several hundred micrometers. It is preferable that the opening of each flow path 330 on the cavity Cv side is provided with a small diameter as the viscosity of the molten material injected into the cavity Cv is smaller. The number of flow paths 330 may be one, not multiple. The opening shape of the flow path 330 is not limited to a circle, and may be, for example, an ellipse or a polygon such as a rectangle.

[0032] A working fluid for pressurizing and pushing out the molded product molded in the cavity Cv flows toward the cavity Cv through each flow path 330. In this embodiment, compressed air is used as the working fluid. Gas other than compressed air or liquid such as oil may be used as the working fluid.

[0033] The pressurizing unit 340 includes a cylinder unit 341, a piston unit 342, an ejector plate 343, a return pin 344, and a return spring 345. The cylinder unit 341 is disposed on the opposite side of the cavity Cv with respect to the nest unit 321 and the storage unit 322. The cylinder unit 341 is fixed to the storage unit 322 by, for example, a bolt or the like. The cylinder unit 341 is configured in a cylindrical shape. The internal space of the cylinder unit 341 communicates with a flow path 330 provided in the nest unit 321.

[0034] The piston portion 342 is disposed in the internal space of the cylinder portion 341. The piston portion 342 has an outer shape that conforms to an inner wall surface 349 of the cylinder portion 341. The piston portion 342 moves in the X direction relative to the cylinder portion 341. In this embodiment, the inner wall surface 349 of the cylinder portion 341 is configured in a cylindrical shape, and the piston portion 342 is configured in a columnar shape. Note that the inner wall surface 349 of the cylinder portion 341 may be configured in a prismatic shape, and the piston portion 342 may be configured in a prismatic shape.

[0035] The ejector plate 343 is disposed on the opposite side of the cavity Cv with respect to the cylinder portion 341. The ejector plate 343 is disposed with a gap between it and the cylinder portion 341. The piston portion 342 is fixed to the center portion of the ejector plate 343. The return pin 344 is fixed to the outer periphery of the ejector plate 343.

[0036] The return pin 344 is a rod-shaped member provided along the X direction. The return pin 344 is inserted into through holes provided in the cylinder portion 341 and the storage portion 322 of the movable mold 320. The ejector plate 343 and the return pin 344 move together with the piston portion 342 relative to the cylinder portion 341 in the X direction.

[0037] The return spring 345 is disposed between the cylinder portion 341 and the ejector plate 343. The return spring 345 is a compression coil spring that expands and contracts along the X direction. The return spring 345 is provided along the return pin 344. One end of the return spring 345 contacts the cylinder portion 341, and the other end of the return spring 345 contacts the ejector plate 343. The return spring 345 pushes back the ejector plate 343 that has approached the cylinder portion 341.

[0038] In this embodiment, the fixed mold 310 and the storage section 322 of the movable mold 320 are formed of a metal material. The fixed mold 310 and the storage section 322 are manufactured by performing cutting, electric discharge machining, or the like on a block of metal material. For example, tool steel, stainless steel, or the like can be used as the metal material for forming the fixed mold 310 and the storage section 322. The fixed mold 310 may be formed of a resin material or a ceramic material instead of a metal material. The storage section 322 may be formed of a resin material or a ceramic material instead of a metal material.

[0039] In this embodiment, the nesting portion 321 of the movable mold 320 is formed of a resin material. The nesting portion 321 is manufactured by stacking layers of a resin material using a three-dimensional modeling device. Therefore, the nesting portion 321 has a structure in which a plurality of layers are stacked. As a resin material for forming the nesting portion 321, for example, cyclic olefin copolymer (COC), polybenzimidazole (PBI), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyacetal (POM), polyamide 66 (PA66), etc. can be used. When the molding material is a crystalline resin material, it is preferable that the nesting portion 321 is formed of a crystalline resin material having a melting point higher than that of the molding material, or an amorphous resin material having a glass transition point higher than that of the molding material. When the molding material is an amorphous resin material, it is preferable that the nesting portion 321 is formed of a crystalline resin material having a melting point higher than the glass transition point of the molding material, or an amorphous resin material having a glass transition point higher than the glass transition point of the molding material. The nesting portion 321 may be manufactured without using a three-dimensional modeling device. The nesting portion 321 may be formed of a metal material or a ceramic material instead of a resin material. The nesting portion 321 and the storage portion 322 may be formed of the same material.

[0040] In this embodiment, the cylinder portion 341, the piston portion 342, the ejector plate 343, and the return pin 344 are formed of a metal material. For example, tool steel, stainless steel, or the like can be used as the metal material for forming the cylinder portion 341, the piston portion 342, the ejector plate 343, and the return pin 344. Note that the cylinder portion 341, the piston portion 342, the ejector plate 343, and the return pin 344 may be formed of a resin material or a ceramic material instead of a metal material.

[0041] Fig. 7 is a first explanatory diagram showing how the molded product MD is extruded, Fig. 8 is a second explanatory diagram showing how the molded product MD is extruded, and Fig. 9 is a third explanatory diagram showing how the molded product MD is extruded.

[0042] 5, before the molten material is injected into the cavity Cv, the cavity Cv and the inside of the cylinder portion 341 are in communication with each other via the flow passage 330. In this state, the air pressure in the cylinder portion 341 is the same as the atmospheric pressure.

[0043] 7, when the molten material is injected into the cavity Cv from the nozzle 130, the opening of the flow passage 330 on the cavity Cv side is blocked by the molten material. Thereafter, the molten material in the cavity Cv cools and solidifies to become the molded product MD.

[0044] 8, when the casting mold 300 is opened, the movement of the movable platen 220 of the mold clamping unit 200 causes the movable mold 320 and the cylinder portion 341 to move away from the fixed mold 310. At this time, the piston portion 342, the ejector plate 343, and the return pin 344 are biased by the return spring 345 and move together with the movable mold 320 and the cylinder portion 341.

[0045] As shown in FIG. 9, when the ejector plate 343 comes into contact with the tip of the ball screw portion 240, the piston portion 342, the ejector plate 343, and the return pin 344 stop moving. In contrast, the movable mold 320 and the cylinder portion 341 move further away from the fixed mold 310 due to the movement of the movable platen 220. Therefore, the piston portion 342 slides on the inner wall surface 349 of the cylinder portion 341. Since the opening of the flow path 330 on the cavity Cv side is blocked by the molded product MD, the air in the cylinder portion 341 and the flow path 330 is compressed by the relative movement of the piston portion 342 with respect to the cylinder portion 341. The molded product MD is pushed toward the fixed mold 310 by the pressure from the compressed air in the flow path 330. When the pressure of the compressed air exceeds a predetermined pressure, the molded product MD is released from the mold. The released molded product MD is transported, for example, by a take-out robot installed next to the injection molding device 10.

[0046] When the molded product MD is removed from the recess 325, the opening of the flow path 330 on the cavity Cv side is opened, and the air pressure in the flow path 330 and the cylinder portion 341 returns to the same pressure as atmospheric pressure. When the molding die 300 is clamped again, the piston portion 342, ejector plate 343, and return pin 344 are pushed back by the return spring 345, returning to the state shown in FIG.

[0047] According to the injection molding apparatus 10 in the present embodiment described above, the molded product MD can be pressed by compressed air flowing through the flow path 330 provided in the movable mold 320 without using an ejector pin, and the molded product MD can be released. When changing the shape of the molded product MD, the changed molded product MD can be molded and released by simply changing the movable mold 320 without changing the pressurizing unit 340. Therefore, when changing the shape of the molded product MD, the effort and cost required to change parts other than the fixed mold 310 and the movable mold 320 can be suppressed. In particular, in the present embodiment, the flow path 330 is provided in the nesting portion 321 of the movable mold 320, which has a surface that defines the cavity Cv. Therefore, when changing the shape of the molded product MD, the storage portion 322 can be used, and the material cost for manufacturing the movable mold 320 can be reduced.

[0048] In this embodiment, the movable mold 320 is provided with a plurality of flow paths 330, so that it is possible to apply pressure to a plurality of locations on the molded product MD, thereby enabling the molded product MD to be effectively released from the mold.

[0049] Moreover, in this embodiment, the compressed air can be pressure-fed to the flow path 330 by the relative movement between the cylinder portion 341 and the piston portion 342. Therefore, the molded product MD can be released with a simple configuration. In particular, in this embodiment, the mold clamping unit 200 moves the movable mold 320, whereby the piston portion 342 moves relative to the cylinder portion 341 fixed to the movable mold 320, and the compressed air is pressure-fed to the flow path 330. Therefore, the compressed air can be pressure-fed to the flow path 330 without a separate device for moving the piston portion 342 relative to the cylinder portion 341.

[0050] B. Second embodiment: Fig. 10 is a side view showing a schematic configuration of an injection molding apparatus 10b in the second embodiment. The second embodiment differs from the first embodiment in that the pressurizing unit 340 shown in Fig. 5 is not attached to the movable mold 320, and compressed air is supplied to the flow path 330 by a pressurizing pump 400. The other configurations are the same as those of the first embodiment unless otherwise specified.

[0051] In this embodiment, the pressure pump 400 is connected to the flow path 330 via a flexible tube 410. The pressure pump 400 is fixed inside the base 20. The pressure pump 400 is driven under the control of the control unit 500. In this embodiment, compressed air is used as the working fluid, so that the pressure pump 400 can be, for example, a centrifugal compressor or a turbo compressor. When a liquid such as oil is used as the working fluid, the pressure pump 400 can be, for example, a volute pump, a gear pump, a piston pump, or the like. When the mold is opened, the control unit 500 drives the pressure pump 400 to pump compressed air into the flow path 330, thereby releasing the molded product MD molded in the cavity Cv. The pressure pump 400 may be referred to as a pressurizing unit.

[0052] According to the injection molding apparatus 10b in this embodiment described above, the molded product MD can be released by pumping compressed air into the flow path 330 using the pressure pump 400 driven under the control of the control unit 500. In particular, in this embodiment, the control unit 500 can adjust the output of the pressure pump 400 to adjust the pressure of the compressed air supplied to the flow path 330.

[0053] C. Other embodiments: (C1) In the injection molding apparatus 10, 10b of each embodiment described above, the flow path 330 through which the working fluid flows toward the cavity Cv is provided in the movable mold 320. In contrast, the flow path 330 may be provided in the fixed mold 310. In this case, for example, the pressurizing pump 400 shown in FIG. 10 is used to pressure-feed the working fluid to the flow path 330 provided in the fixed mold 310, thereby pressurizing and extruding the molded product. The flow paths 330 may also be provided in the fixed mold 310 and the movable mold 320. For example, the pressurizing pump 400 can be used to pressure-feed the working fluid to the flow path 330 provided in the fixed mold 310. For example, the pressurizing unit 340 or the pressurizing pump 400 can be used to pressure-feed the working fluid to the flow path 330 provided in the movable mold 320. For example, the pressurizing unit 340 or the pressurizing pump 400 can be used to pressure-feed the working fluid to the flow path 330 provided in one of the fixed mold 310 and the movable mold 320 to which the molded product is attached. The molded product can be pressurized and extruded by pressure-feeding the working fluid to the flow path 330 provided in one of the fixed mold 310 and the movable mold 320 to which the molded product is attached.

[0054] (C2) In the injection molding apparatus 10, 10b of each of the above-described embodiments, the injection molding apparatus 10, 10b may not be provided with the pressurizing unit 340 or the pressurizing pump 400. In this case, for example, a factory pipeline through which compressed air flows and the flow path 330 of the molding die 300 may be connected via a valve that is opened and closed under the control of the control unit 500, and compressed air as the working fluid may be supplied to the flow path 330 by opening the valve.

[0055] (C3) In the injection molding apparatuses 10 and 10b of the above-described embodiments, the movable mold 320 has a nested structure divided into the nested portion 321 and the storage portion 322. In contrast, the movable mold 320 does not have to have a nested structure. That is, the nested portion 321 and the storage portion 322 may be integrated. The nested portion 321, the storage portion 322, and the cylinder portion 341 may be integrated, or the nested portion 321 and the storage portion 322 may not be integrated, and the storage portion 322 and the cylinder portion 341 may be integrated. Also, the fixed mold 310 may have a nested structure.

[0056] (C4) In the injection molding apparatuses 10 and 10b of the above-described embodiments, the movable mold 320 is manufactured by a three-dimensional modeling apparatus and has a structure in which multiple layers made of a resin material are laminated. In contrast, the movable mold 320 does not have to have a structure in which multiple layers are laminated. Furthermore, the fixed mold 310 may have a structure in which multiple layers made of a resin material are laminated by being manufactured by a three-dimensional modeling apparatus.

[0057] D. Other forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various forms without departing from the spirit of the present disclosure. For example, the present disclosure can be realized in the following forms. The technical features in the above-mentioned embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined in order to solve some or all of the problems of the present disclosure, or to achieve some or all of the effects of the present disclosure. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0058] (1) According to a first aspect of the present disclosure, there is provided an injection molding apparatus. The injection molding apparatus includes a fixed mold, a movable mold facing the fixed mold, a mold clamping section for moving the movable mold relative to the fixed mold, and an injection section for injecting molten material into a cavity defined by the fixed mold and the movable mold. At least one of the fixed mold and the movable mold is formed with a flow path communicating with the cavity, through which a working fluid flows to pressurize and extrude a molded product in the cavity. With this type of injection molding device, the molded product can be pressurized and extruded by the working fluid flowing through the flow path provided in the fixed mold or the working fluid flowing through the flow path provided in the movable mold without using an ejector pin, which makes it possible to reduce the effort and cost required to change parts other than the fixed mold and the movable mold when changing the shape of the molded product.

[0059] (2) In the injection molding apparatus of the above aspect, at least one of the fixed mold and the movable mold may be formed with a plurality of the flow paths. According to the injection molding apparatus of this type, pressure can be applied to a plurality of points on the molded product, so that the molded product can be effectively extruded.

[0060] (3) The injection molding apparatus of the above aspect may further include a pressurizing unit that pressure-feeds the working fluid to the flow path. According to the injection molding apparatus of this embodiment, the working fluid is pumped from the pressurizing portion to the flow passage, thereby extruding the molded product.

[0061] (4) In the injection molding apparatus of the above aspect, the pressurizing section may have a cylinder section communicating with the flow path and a piston section disposed within the cylinder section, and the working fluid may be pressurized and pumped into the flow path by relative movement of the piston section with respect to the cylinder section. According to the injection molding device of this aspect, the working fluid can be pressure-fed to the flow passage by the relative movement between the cylinder portion and the piston portion.

[0062] (5) In the injection molding apparatus of the above form, the flow path may be formed in the movable mold, and the mold clamping unit may move the cylinder portion together with the movable mold, thereby moving the piston portion relative to the cylinder portion. According to the injection molding apparatus of this aspect, it is possible to relatively move the cylinder portion and the piston portion by the mold clamping portion without providing a separate device for relatively moving the cylinder portion and the piston portion.

[0063] (6) In the injection molding apparatus of the above aspect, at least one of the fixed mold and the movable mold may have a nesting portion that defines the cavity, and a storage portion that stores the nesting portion. According to the injection molding apparatus of this form, when the shape of the molded product is to be changed, parts other than the insert portion can be reused.

[0064] (7) In the injection molding apparatus of the above aspect, at least one of the fixed mold and the movable mold may have a structure in which a plurality of layers are laminated. According to this type of injection molding apparatus, a fixed mold and a movable mold in which a plurality of layers are laminated can be manufactured using a three-dimensional modeling device.

[0065] (8) According to a second aspect of the present disclosure, there is provided a mold for injection molding. The mold includes a fixed mold and a movable mold that faces the fixed mold and moves relative to the fixed mold. The fixed mold and the movable mold define a cavity to be filled with a molten material, and at least one of the fixed mold and the movable mold is provided with a plurality of flow paths that communicate with the cavity, through which a working fluid flows to pressurize and extrude a molded product in the cavity. With this type of mold, the molded product can be pressurized and extruded by the working fluid flowing through the flow path provided in the fixed mold or the working fluid flowing through the flow path provided in the movable mold without using an ejector pin. Therefore, when changing the shape of the molded product, it is possible to suppress the effort and cost required to change parts other than the fixed mold and the movable mold.

[0066] The present disclosure may be realized in various forms other than an injection molding apparatus, for example, in the form of a mold for injection molding. [Explanation of symbols]

[0067] 10... injection molding apparatus, 100... injection section, 101... hopper, 110... plasticizing section, 120... injection control mechanism, 130... nozzle, 200... mold clamping section, 210... fixed platen, 220... movable platen, 230... tie bar, 240... ball screw section, 250... mold drive section, 300... molding die, 305... guide pin, 310... fixed die, 320... movable die, 321... nesting section, 322... storage section, 325... recess, 330... flow path, 340... pressure section, 341... cylinder section, 342... piston section, 343... ejector plate, 344... return pin, 345... return spring, 400... pressure pump, 410... tube, 500... control section

Claims

1. Fixed type and A movable die facing the fixed die; a mold clamping unit that moves the movable mold relative to the fixed mold; an injection section that injects a molten material into a cavity defined by the fixed mold and the movable mold; Equipped with a flow path communicating with the cavity is formed in the movable die, the flow path through which a working fluid flows to pressurize and extrude a molded product in the cavity; a cylinder portion disposed on the opposite side of the cavity with respect to the movable mold, the cylinder portion communicating with the flow path, and a piston portion disposed within the cylinder portion, the pressurizing portion pressurizing the working fluid to the flow path by relative movement of the piston portion with respect to the cylinder portion; Injection molding equipment.

2. An injection molding apparatus as claimed in claim 1, The pressure applying unit is an ejector plate disposed on an opposite side of the cavity with respect to the cylinder portion, the ejector plate having the piston portion fixed thereto; a return spring disposed between the ejector plate and the cylinder portion; and the mold clamping unit moves the ejector plate closer to the cylinder portion while moving the movable mold away from the fixed mold, thereby moving the piston portion relative to the cylinder portion and causing the pressurizing unit to pressure-feed the working fluid to the flow path; The return spring pushes the ejector plate back away from the cylinder portion while the mold clamping portion moves the movable mold toward the fixed mold.

3. 2. The injection molding apparatus of claim 1, An injection molding apparatus, wherein the movable mold has a plurality of the flow paths formed therein.

4. 4. The injection molding apparatus according to claim 1, At least one of the fixed mold and the movable mold has a nesting portion that defines the cavity, and a storage portion that stores the nesting portion.

5. 5. The injection molding apparatus according to claim 1, At least one of the fixed mold and the movable mold has a structure in which a plurality of layers are laminated.

6. A mold for injection molding, comprising: Fixed type and a movable die that faces the fixed die and moves relative to the fixed die; Equipped with the fixed mold and the movable mold define a cavity to be filled with a molten material; a flow path communicating with the cavity is formed in the movable die, the flow path through which a working fluid flows to pressurize and extrude a molded product in the cavity; a cylinder portion disposed on the opposite side of the cavity with respect to the movable mold, the cylinder portion communicating with the flow path, and a piston portion disposed within the cylinder portion, the pressurizing portion pressurizing the working fluid to the flow path by relative movement of the piston portion with respect to the cylinder portion; Molding mold.

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