Injection molding apparatus

Abstract

To provide an injection molding apparatus having a small-sized nozzle.SOLUTION: An injection molding apparatus includes a plasticizing unit that plasticizes a material to generate a shaping material, a nozzle that communicates with the plasticizing unit and discharges the shaping material, and a mold clamping device that opens and closes a mold to which the shaping material is discharged from the nozzle, in which the nozzle has a flow path through which the shaping material flows, a discharge port that communicates with the flow path and discharges the shaping material, and an opening / closing mechanism that is at least partially located in the flow path and opens and closes the discharge port, the injection molding apparatus further includes a spring that applies a biasing force to the opening / closing mechanism, and at least a part of the spring is supported by the plasticizing unit.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an injection molding apparatus. [Background technology]

[0002] For example, Patent Document 1 discloses a valve nozzle that uses resin pressure to operate a piston to open and close a gate. In this valve nozzle, when the resin pressure is below a predetermined value, a coil spring urges the piston in the direction away from the gate, thereby keeping the gate closed. The coil spring is provided in a flow path for molten resin provided inside the valve nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-151036 Summary of the Invention [Problem to be solved by the invention]

[0004] In an injection molding apparatus in which a spring is provided in a flow path inside the nozzle, the size of the nozzle becomes large, which may impose restrictions on the shape of the mold that can be used for injection molding. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided an injection molding apparatus comprising: a plasticizing unit that plasticizes a material to produce a modeling material; a nozzle that communicates with the plasticizing unit and dispenses the modeling material; and a clamping device that opens and closes a mold into which the modeling material is dispensed from the nozzle, wherein the nozzle has a flow path through which the modeling material flows, a discharge port that communicates with the flow path and dispenses the modeling material, and an opening / closing mechanism at least partially located within the flow path and opening and closing the discharge port, and further comprising a spring that applies a biasing force to the opening / closing mechanism, at least a portion of the spring being supported by the plasticizing unit. [Brief explanation of the drawings]

[0006] [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 an injection unit. [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. 2 is a perspective view of a barrel and a nozzle. [Figure 7] FIG. 2 is a perspective view of the barrel and nozzle cut along a cross section including the flow path. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 2 is a cross-sectional view schematically showing the configuration of the periphery of an opening / closing mechanism. [Figure 11] FIG. 2 is a cross-sectional view schematically showing the configuration of the periphery of an opening / closing mechanism. [Figure 12] FIG. 4 is a diagram illustrating the position of a heating unit of the injection unit. [Figure 13] FIG. 2 is a cross-sectional view of the barrel, barrel case, and nozzle. [Figure 14] FIG. 10 is a diagram illustrating the position of a spring in the second embodiment. [Figure 15] FIG. 10 is a diagram illustrating the position of a spring in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] A. First embodiment: FIG. 1 is a top view showing a schematic configuration of injection molding apparatus 10. FIG. 2 is a perspective view showing a schematic configuration of injection molding apparatus 10. FIGS. 1 and 2 show arrows representing mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to the horizontal plane. The Z direction is parallel to the vertical direction. The X, Y, and Z directions in FIGS. 1 and 2 and the X, Y, and Z directions in other figures indicate the same directions. When specifying a direction, positive and negative signs are used in combination to indicate the direction, with "+" indicating the positive direction indicated by the arrow and "-" indicating the negative direction opposite to the direction indicated by the arrow.

[0008] The injection molding apparatus 10 includes an injection unit 20, a mold clamping device 30, and a control unit 40. The injection molding apparatus 10 produces a molded product by injecting a molding material from the injection unit 20 into a molding die 400 attached to the mold clamping device 30. In this specification, injecting the molding material is also referred to as discharging the molding material. The injection molding apparatus 10 is a horizontal injection molding apparatus, and the injection unit 20 and the mold clamping device 30 are aligned horizontally. The control unit 40 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. The control unit 40 may also be configured as a circuit.

[0009] A metal molding die 400 is attached to the mold clamping unit 30. The metal molding die 400 is called a mold. The molding die 400 includes a fixed die 401 and a movable die 402. The fixed die 401 is a die that is fixed relative to the injection unit 20. The movable die 402 is a die that can be moved forward and backward in the mold clamping direction relative to the fixed die 401 by the mold clamping unit 30. In this embodiment, the mold clamping direction is the -Y direction.

[0010] Mold clamping device 30 has the function of opening and closing fixed mold 401 and movable mold 402. Under the control of control unit 40, mold clamping device 30 drives mold drive unit 31 composed of a motor to rotate ball screw 32, and moves movable mold 402 connected to ball screw 32 relative to fixed mold 401, thereby opening and closing casting mold 400.

[0011] A hopper 50 into which the material for the molded article is introduced is connected to the injection unit 20. The material for the molded article may be, for example, a thermoplastic resin formed into pellets. Examples of the thermoplastic resin include ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyacetal), PP (polypropylene), and PBT (polybutylene terephthalate). The material for the molded article may contain metal or ceramic in addition to the thermoplastic resin. The material may be supplied to the injection unit 20 not only through the hopper 50 but also, for example, via a tube through which the material is pressure-fed.

[0012] The injection unit 20 plasticizes at least a portion of the material supplied from the hopper 50 to generate a modeling material, and then injects the generated modeling material into a cavity defined between the fixed mold 401 and the movable mold 402. 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 above its glass transition point. For a material that does not undergo glass transition, plasticization refers to raising the temperature of the material above its melting point.

[0013] 3 is a cross-sectional view showing a schematic configuration of the injection unit 20. The injection unit 20 includes a plasticizing section 21, a suction delivery section 22, and a nozzle .

[0014] The plasticizing unit 21 generates a shaping material by plasticizing at least a portion of the material supplied from the hopper 50. The plasticizing unit 21 includes a flat screw 110, a screw case 111, a barrel 130, a barrel case 139, and a first heating unit 140.

[0015] The flat screw 110 is housed in a screw case 111. The flat screw 110 is rotated by a drive motor 112 within the screw case 111 around a drive shaft 119 of the drive motor 112. A central axis RX, which is the rotation center of the flat screw 110, coincides with the center of the drive shaft 119 of the drive motor 112 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 110 by the drive motor 112 is controlled by the control unit 40. The flat screw 110 may be driven by the drive motor 112 via a reducer. The flat screw 110 is also called a rotor or simply a screw.

[0016] The barrel 130 is housed in a barrel case 139. A communication hole 131 is formed in the center of the barrel 130. The communication hole 131 is connected to a flow path 170 through which the modeling material flows. A cylinder 151 and a nozzle 23, which will be described later, are connected to the flow path 170. A check valve 132 is provided in the flow path 170, upstream of the cylinder 151. The check valve 132 prevents the modeling material from flowing back from the nozzle 23 side to the flat screw 110 side.

[0017] The first heating section 140 heats the modeling material in the plasticizing section 21. The first heating section 140 is a heater.

[0018] FIG. 4 is a perspective view showing a schematic configuration of the flat screw 110. The flat screw 110 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 123 is formed around a central portion 122 on a groove-forming surface 121 of the flat screw 110 facing the barrel 130. The groove 123 communicates with a material inlet 124 formed on the side surface of the flat screw 110. Material supplied from the hopper 50 is supplied to the groove 123 through the material inlet 124. The grooves 123 are separated by ridge portions 125. While FIG. 4 shows an example in which three grooves 123 are formed, the number of grooves 123 may be one or more. The groove 123 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 122 to the outer periphery.

[0019] 5 is a schematic plan view of barrel 130. Barrel 130 has an opposing surface 133 that faces groove-forming surface 121 of flat screw 110. A communication hole 131 is formed in the center of opposing surface 133. A plurality of guide grooves 134 are formed in opposing surface 133, connected to communication hole 131 and extending spirally from communication hole 131 toward the outer periphery. Note that guide grooves 134 do not necessarily have to be provided in barrel 130. Furthermore, guide grooves 134 do not necessarily have to be connected to communication hole 131.

[0020] The material supplied to the groove 123 of the flat screw 110 is plasticized between the flat screw 110 and the barrel 130 by the rotation of the flat screw 110 and the heating of the first heating section 140, and flows along the groove 123 and the guide groove 134 by the rotation of the flat screw 110, and is guided to the central section 122 of the flat screw 110. The material that has flowed into the central section 122 flows out into the flow path 170 from a communication hole 131 provided in the center of the barrel 130.

[0021] As shown in FIG. 3, the suction delivery unit 22 has a cylinder 151, a plunger 152, and a plunger driver 153. The suction delivery unit 22 has the function of injecting the modeling material in the cylinder 151 into the cavity of the molding die 400. Under the control of the control unit 40, the suction delivery unit 22 controls the injection amount, injection speed, and injection pressure of the modeling material from the nozzle 23. The cylinder 151 is a substantially cylindrical member connected to the flow path 170, and has a plunger 152 inside. The plunger 152 slides inside the cylinder 151 and pressure-feeds the modeling material in the cylinder 151 to the nozzle 23. The plunger 152 is driven by the plunger driver 153, which is composed of a motor.

[0022] The nozzle 23 is in communication with the plasticizing section 21. A flow path 170 is formed in the nozzle 23. The nozzle 23 is in communication with the flow path 170 and has an outlet 24 that discharges the modeling material. The plunger 152 pressurizes the modeling material in the cylinder 151 to the nozzle 23, causing the modeling material to be injected from the outlet 24 into the molding die 400.

[0023] FIG. 6 is a perspective view of the barrel 130 and the nozzle 23. FIG. 7 is a perspective view of the barrel 130 and the nozzle 23 cut at a cross section including the flow path 170. As shown in FIG. 7, the nozzle 23 is provided with an opening / closing mechanism 210 that opens and closes the discharge port 24. The opening / closing mechanism 210 is provided so that at least a portion thereof is located within the flow path 170. In this embodiment, the opening / closing mechanism 210 is composed of a piston 220 and a lever 230. In FIG. 7, to clearly show the opening / closing mechanism 210, the cross sections of the piston 220 and the lever 230 are each hatched. The injection unit 20 also includes a spring 240 that applies a biasing force to the opening / closing mechanism 210.

[0024] FIG. 8 is a perspective view of the spring 240. In this embodiment, the spring 240 is a torsion spring. The spring 240 includes a first coil portion 241, a second coil portion 242, a first arm portion 243, a second arm portion 244, and a third arm portion 245. The first coil portion 241 and the second coil portion 242 are arranged such that the axis of the first coil portion 241 and the axis of the second coil portion 242 coincide with each other. Hereinafter, the axis of the first coil portion 241 and the axis of the second coil portion 242 are also referred to as the axis AX of the spring 240. The first coil portion 241 and the second coil portion 242 are also collectively referred to as the coil portions. In this embodiment, the direction along the axis AX of the spring 240 is the X direction. The first coil portion 241 is arranged on the +X direction side of the second coil portion 242. The first arm portion 243 extends in the -Y direction from the end of the first coil portion 241 on the +X direction side. The second arm portion 244 extends in the -Y direction from the end of the second coil portion 242 on the -X direction side. The first arm portion 243 and the second arm portion 244 are fixed to the barrel 130. The third arm portion 245 is provided between the first coil portion 241 and the second coil portion 242, and connects the end of the first coil portion 241 on the -X direction side and the end of the second coil portion 242 on the +X direction side. The third arm portion 245 protrudes in the -Z direction beyond the outer diameter of the coil portions.

[0025] Fig. 9 is a perspective view of spring 240 and lever 230. Figs. 10 and 11 are cross-sectional views that schematically show the configuration around opening / closing mechanism 210. Fig. 10 shows a state in which discharge port 24 is closed, and Fig. 11 shows a state in which discharge port 24 is open. The structure and operation of opening / closing mechanism 210 will be described below with reference to Figs. 7 and 9 to 11.

[0026] The spring 240 and lever 230 are attached to the barrel 130 by a shaft member 250 extending in the X direction. A portion of the shaft member 250 is located inside the coil portion of the spring 240 and in a through-hole (not shown) provided at the end of the lever 230 on the +Z direction side, penetrating the lever 230 in the X direction. In other words, the spring 240 is attached to and supported by the plasticizing portion 21. The lever 230 is rotatable within the YZ plane around the shaft member 250. In this embodiment, the axis BX of the shaft member 250 coincides with the axis AX of the spring 240. Note that the axis BX of the shaft member 250 does not have to coincide with the axis AX of the spring 240. Furthermore, a groove 231 penetrating the lever 230 in the X direction is formed on the surface of the lever 230 on the -Y direction side. A third arm portion 245 of the spring 240 is disposed in the groove 231. That is, the lever 230 comes into contact with the spring 240 in the groove 123. The spring 240 applies a biasing force to the lever 230 so that the lever 230 rotates clockwise around the axis BX of the shaft member 250 as viewed from the -X direction. At this time, the first arm portion 243 and the second arm portion 244 of the spring 240 are supported by the plasticizing portion 21, and the third arm portion 245 of the spring 240 is supported by the opening / closing mechanism 210. The lever 230 and the shaft member 250 may be formed as a single unit.

[0027] Lever 230 transmits the biasing force of spring 240 to piston 220. A first end surface 232, which is a surface that protrudes in the +Y direction, is formed at the end of lever 230 on the -Z direction side. As shown in FIGS. 10 and 11 , lever 230 contacts piston 220 at first end surface 232. The entire first end surface 232 may contact piston 220, or only a portion of it may contact piston 220. Hereinafter, the portion of lever 230 that contacts piston 220 will be referred to as a first contact portion. That is, first end surface 232 includes the first contact portion.

[0028] Lever 230 is made of a material with lower thermal conductivity than piston 220. In this embodiment, lever 230 is made of PEEK (polyether ether ketone). Note that lever 230 may be made of resin other than PEEK, ceramic, metal, or the like.

[0029] The piston 220 opens and closes the discharge port 24 of the nozzle 23. The piston 220 is provided so that at least a portion thereof is located within the flow path 170. The piston 220 is provided so as to be movable within the flow path 170 in the direction in which the modeling material flows. In this embodiment, the piston 220 is provided so as to be movable in the Y direction. When the piston 220 moves in the +Y direction and the end of the piston 220 on the +Y direction side comes into contact with the discharge port 24, the discharge port 24 is closed. When the piston 220 moves in the -Y direction and the end of the piston 220 on the +Y direction side moves away from the discharge port 24, the discharge port 24 is opened. Hereinafter, the end of the piston 220 on the +Y direction side will also be referred to as the front end, and the end on the -Y direction side will also be referred to as the rear end.

[0030] The rear end side of the piston 220 is disposed inside a first hole 201 formed in the nozzle 23 and penetrating the nozzle 23 in the Y direction. The rear end face of the piston 220 contacts a first end face 232 of the lever 230. Hereinafter, the rear end face of the piston 220 will be referred to as a second end face 221. The portion of the piston 220 that contacts the lever 230 will be referred to as a second contact portion. That is, the second end face 221 includes the second contact portion. The area of ​​the second end face 221 including the second contact portion is larger than the area of ​​the first end face 232 including the first contact portion. In other words, the area of ​​the first end face 232 including the first contact portion is smaller than the area of ​​the second end face 221 including the second contact portion.

[0031] In this embodiment, the piston 220 is made of SUS. However, the piston 220 may be made of metal other than SUS, ceramic, or the like. The piston 220 is preferably made of a heat-resistant material.

[0032] When there is no modeling material in the flow channel 170 or when the pressure of the modeling material in the flow channel 170 is lower than a predetermined value, the piston 220 is biased in the +Y direction by the biasing force of the spring 240, thereby closing the discharge port 24, as shown in FIG. 10 . Specifically, the third arm portion 245 of the spring 240 biases the lever 230, causing the lever 230 to rotate clockwise around the shaft member 250 as viewed from the −X direction, and the first end surface 232 of the lever 230 presses the second end surface 221 of the piston 220. This biases the piston 220 in the +Y direction. When the pressure of the modeling material in the flow channel 170 is higher than a predetermined value, the pressure of the modeling material overcomes the biasing force of the spring 240, and the piston 220 moves in the −Y direction as shown in FIG. 11 , thereby opening the discharge port 24. Here, the predetermined value of the pressure of the modeling material is determined based on the type of modeling material, the biasing force of the spring 240, and the like.

[0033] As shown in Figures 6, 10, and 11, the spring 240 is provided in a recess 135 formed in the surface of the barrel 130 facing the nozzle 23. In this embodiment, the surface of the barrel 130 facing the nozzle 23 is the surface on the +Y direction side of the barrel 130. The spring 240 is provided in the recess 135 so that its axis AX is located closer to the plasticizing section 21 than the boundary between the plasticizing section 21 and the nozzle 23. In this embodiment, the position where the surface on the +Y direction side of the barrel 130 contacts the surface on the -Y direction side of the nozzle 23 corresponds to the boundary between the plasticizing section 21 and the nozzle 23. In Figures 10 and 11, the boundary between the plasticizing section 21 and the nozzle 23 is indicated by a dashed line L1.

[0034] FIG. 12 is a diagram illustrating the position of the heating section of the injection unit 20. In FIG. 12, the first heating section 140 embedded inside the barrel 130 is indicated by a dashed line. In this embodiment, the first heating section 140 is composed of four rod-shaped heaters extending in the X direction. Note that the first heating section 140 may be composed of one to three or five or more heaters, and may have a shape other than a rod shape. The nozzle 23 also has a second heating section 260 that heats the modeling material in the flow path 170. The second heating section 260 is a coil heater that is wound around the nozzle 23. A space is provided between the second heating section 260 and the spring 240.

[0035] 13 is a cross-sectional view of the barrel 130, the barrel case 139, and the nozzle 23. As shown in FIG. 13, the barrel 130 has a heat insulating member 270. The heat insulating member 270 is embedded inside the barrel 130 so as to be located between the first heating unit 140 and the spring 240. The heat insulating member 270 is made of, for example, glass fiber or ceramic. Note that the heat insulating member 270 may be provided on the outer surface of the barrel 130 so as to be located between the first heating unit 140 and the spring 240.

[0036] The plasticizing unit 21 has a cooling unit 280 that cools the plasticizing unit 21. In this embodiment, the cooling unit 280 is provided in the barrel case 139. The cooling unit 280 is a refrigerant flow path through which a refrigerant flows. The cooling unit 280 is connected to a refrigerant pump (not shown) that supplies a refrigerant to the cooling unit 280. For example, a liquid such as water or oil, or a gas such as carbon dioxide can be used as the refrigerant. The temperature of the refrigerant flowing through the cooling unit 280 is controlled by the control unit 40. The plasticizing unit 21 is cooled by the refrigerant flowing through the cooling unit 280. The cooling unit 280 may also be provided in the barrel 130.

[0037] According to the injection molding apparatus 10 of the first embodiment described above, the spring 240 that applies a biasing force to the opening / closing mechanism 210 that opens and closes the discharge port 24 of the nozzle 23 is supported by the plasticizing unit 21 and is not provided within the flow path 170. This allows the size of the nozzle 23 to be reduced, reducing the possibility of limitations on the shape of the molding die 400 that can be used for injection molding. Furthermore, if the spring 240 were provided within the flow path 170, it would be difficult to increase the temperature of the modeling material flowing through the flow path 170 due to the heat resistance of the spring 240. However, in this embodiment, since the spring 240 is not provided within the flow path 170, the temperature of the modeling material flowing through the flow path 170 can be increased.

[0038] In this embodiment, the spring 240 is a torsion spring, and the axis AX of the spring 240 is located closer to the plasticizing section 21 than the boundary between the plasticizing section 21 and the nozzle 23. This allows the size of the nozzle 23 to be reduced, reducing the possibility of restrictions being placed on the shape of the molding die 400 that can be used for injection molding.

[0039] Furthermore, in this embodiment, the spring 240 is located in the recess 135 of the plasticizing portion 21. This allows the size of the nozzle 23 to be reduced, reducing the possibility of restrictions being placed on the shape of the molding die 400 that can be used for injection molding.

[0040] In this embodiment, the plasticizing unit 21 has a heat insulating member 270 provided between the spring 240 and the first heating unit 140. Therefore, a decrease in strength of the spring 240 due to the influence of heat from the first heating unit 140 can be suppressed.

[0041] Furthermore, in this embodiment, a space is provided between the spring 240 and the second heating unit 260. Therefore, the air existing between the spring 240 and the second heating unit 260 insulates the heat of the second heating unit 260, thereby suppressing a decrease in strength of the spring 240 due to the influence of the heat of the second heating unit 260.

[0042] Furthermore, in this embodiment, the area of ​​first end face 232 including the first contact portion of lever 230 is smaller than the area of ​​second end face 221 including the second contact portion of piston 220. This makes it possible to suppress the heat from piston 220 from being transferred to lever 230. As a result, it is possible to suppress the heat from piston 220 from being transferred to spring 240 that is in contact with lever 230, and to suppress a decrease in strength of spring 240 due to the influence of heat.

[0043] Furthermore, in this embodiment, the thermal conductivity of lever 230 is lower than the thermal conductivity of piston 220. Therefore, it is possible to prevent heat from piston 220 from being transferred to spring 240 via lever 230, and to prevent a decrease in strength of spring 240 due to the influence of heat.

[0044] B. Second embodiment: 14 is a diagram illustrating the position of spring 240b in the second embodiment. In the second embodiment, the position of spring 240b and the length of lever 230b in the Z direction are different from those in the first embodiment. Also, in the second embodiment, barrel 130 does not have heat insulating member 270. The configuration of each part of injection molding apparatus 10 other than spring 240b, lever 230b, and heat insulating member 270 is the same as that in the first embodiment.

[0045] As shown in FIG. 14, the spring 240b is located in an area A1 that does not overlap with the first heating unit 140 in the direction in which the plasticizing unit 21 and the nozzle 23 are aligned. In this embodiment, the direction in which the plasticizing unit 21 and the nozzle 23 are aligned is the Y direction. The spring 240b is attached to the barrel 130 so as to be located between two first heating units 140 that are arranged on the +Z direction side of the flow path 170 in the Z direction. Furthermore, because the spring 240b is located on the +Z direction side of the spring 240 of the first embodiment, the length in the Z direction of the lever 230b is longer than the lever 230 of the first embodiment.

[0046] According to the second embodiment described above, the heat of the first heating section 140 is less likely to be transmitted to the spring 240b than when the spring 240b is positioned in a region overlapping with the first heating section 140 in the direction in which the plasticizing section 21 and the nozzle 23 are aligned. Therefore, it is possible to suppress a decrease in the strength of the spring 240b due to the influence of the heat from the first heating section 140.

[0047] C. Third embodiment: 15 is a diagram illustrating the position of spring 240c in the third embodiment. In the third embodiment, the position of spring 240c and the length of lever 230c in the Z direction are different from those in the first embodiment. Also, in the third embodiment, barrel 130 does not have heat insulating member 270. The configuration of each part of injection molding apparatus 10 other than spring 240c, lever 230c, and heat insulating member 270 is the same as that in the first embodiment.

[0048] The spring 240c is provided at a position where a distance L2 between the spring 240c and the cooling unit 280 is shorter than a distance L3 between the spring 240c and the first heating unit 140. Here, the distance L2 is the shortest distance between the spring 240c and the cooling unit 280, and the distance L3 is the shortest distance between the spring 240c and the first heating unit 140. Note that, when there are multiple first heating units 140, the distance L3 is the shortest distance between the spring 240c and the first heating unit 140 that is closest to the spring 240c. As shown in FIG. 15 , the distance L2 between the cooling unit 280 provided on the +Z direction side of the flow path 170 and the spring 240c is shorter than the distance L3 between the first heating unit 140 located closest to the +Z direction and the spring 240c. Furthermore, since the spring 240c is located further in the +Z direction than the spring 240 of the first embodiment, the length of the lever 230c in the Z direction is longer than that of the lever 230 of the first embodiment.

[0049] According to the third embodiment described above, the distance between the spring 240c and the cooling unit 280 is shorter than the distance between the spring 240c and the first heating unit 140, and therefore the spring 240c is cooled by the cooling unit 280. Therefore, a decrease in strength of the spring 240c due to the influence of heat from the first heating unit 140 can be suppressed.

[0050] D. Other Embodiments: (D-1) In the above embodiment, the spring 240 is a torsion spring. However, the spring 240 may have any shape as long as it is capable of applying a biasing force to the opening / closing mechanism 210, and may be a coil spring, a leaf spring, or the like. The following describes a case where the spring 240 is a coil spring. The spring 240 is provided between the opening / closing mechanism 210 and the plasticizing unit 21. Specifically, one end of the spring 240 is fixed to a surface on the +Y direction side of the barrel 130, and the other end is fixed to a surface on the −Y direction side of the lever 230. The spring 240 applies a biasing force to the lever 230 so that the lever 230 rotates clockwise around the axis BX of the shaft member 250 as viewed from the −X direction. At this time, one end of the spring 240 is supported by the plasticizing unit 21, and the other end of the spring 240 is supported by the opening / closing mechanism 210. It should be noted that either one end or the other end of the spring 240 does not have to be fixed.

[0051] (D-2) In the above embodiment, the spring 240 is located in the recess 135 of the plasticized portion 21. However, the spring 240 does not have to be located in the recess 135. Furthermore, the plasticized portion 21 does not have to have the recess 135.

[0052] (D-3) In the above embodiment, the plasticizing section 21 has the heat insulating member 270. In contrast, the plasticizing section 21 does not necessarily have to have the heat insulating member 270.

[0053] (D-4) In the above embodiment, a space is provided between the spring 240 and the second heating unit 260. In contrast to this, a space does not have to be provided between the spring 240 and the second heating unit 260.

[0054] (D-5) In the above embodiment, the area of ​​first end face 232 including the first contact portion is smaller than the area of ​​second end face 221 including the second contact portion. In contrast, the area of ​​first end face 232 including the first contact portion does not have to be smaller than the area of ​​second end face 221 including the second contact portion.

[0055] (D-6) In the above embodiment, the thermal conductivity of lever 230 is lower than the thermal conductivity of piston 220. However, the thermal conductivity of lever 230 does not have to be lower than the thermal conductivity of piston 220.

[0056] (D-7) In the above embodiment, the opening and closing mechanism 210 is composed of the piston 220 and the lever 230. In contrast to this, the opening and closing mechanism 210 may be composed of one member, or may be composed of three or more members.

[0057] (D-8) In the above embodiment, the injection molding apparatus 10 is a horizontal injection molding apparatus. However, the injection molding apparatus 10 may be a vertical injection molding apparatus.

[0058] E. Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following forms. The technical features in the above embodiments corresponding to the technical features in each form described below can be appropriately replaced or combined 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 a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0059] (1) According to a first aspect of the present disclosure, there is provided an injection molding apparatus comprising: a plasticizing unit that plasticizes a material to produce a modeling material; a nozzle that communicates with the plasticizing unit and dispenses the modeling material; and a clamping device that opens and closes a mold into which the modeling material is dispensed from the nozzle, wherein the nozzle has a flow path through which the modeling material flows, a discharge port that communicates with the flow path and dispenses the modeling material, and an opening / closing mechanism at least partially located within the flow path and opening and closing the discharge port, and further comprising a spring that applies a biasing force to the opening / closing mechanism, and at least a portion of the spring is supported by the plasticizing unit. According to this embodiment, since the spring is not provided inside the flow path, the size of the nozzle can be reduced, and the possibility of imposing restrictions on the shape of the mold that can be used for injection molding can be reduced.

[0060] (2) In the above embodiment, the spring may be a torsion spring, and the axis of the spring may be located closer to the plasticizing section than the boundary between the plasticizing section and the nozzle. According to this embodiment, the size of the nozzle can be reduced, and the possibility of imposing restrictions on the shape of the mold that can be used for injection molding can be reduced.

[0061] (3) In the above embodiment, the plasticized portion may have a recess, and the spring may be located in the recess. According to this embodiment, the size of the nozzle can be reduced, and the possibility of imposing restrictions on the shape of the mold that can be used for injection molding can be reduced.

[0062] (4) In the above embodiment, the plasticizing unit may have a first heating unit that heats the molding material in the plasticizing unit, and an insulating member that is provided between the spring and the first heating unit. According to this embodiment, it is possible to suppress a decrease in strength of the spring due to the influence of heat from the first heating section.

[0063] (5) In the above aspect, the nozzle may have a second heating unit that heats the modeling material in the flow path, and a space may be provided between the spring and the second heating unit. According to this embodiment, the heat of the second heating unit is insulated by the air present between the spring and the second heating unit, so that a decrease in strength of the spring due to the influence of the heat of the second heating unit can be suppressed.

[0064] (6) In the above embodiment, the plasticizing unit may have a first heating unit that heats the molding material within the plasticizing unit, and the spring may be located in an area that does not overlap with the first heating unit in the direction in which the plasticizing unit and the nozzle are aligned. According to this embodiment, it is possible to suppress a decrease in strength of the spring due to the influence of heat from the first heating section.

[0065] (7) In the above embodiment, the plasticizing unit may have a first heating unit that heats the molding material in the plasticizing unit and a cooling unit that cools the plasticizing unit, and the distance between the spring and the cooling unit may be shorter than the distance between the spring and the first heating unit. According to this embodiment, it is possible to suppress a decrease in strength of the spring due to the influence of heat from the first heating section.

[0066] (8) In the above embodiment, the opening / closing mechanism may have a piston, at least a portion of which is provided within the flow path, that opens and closes the discharge port, and a lever that contacts the spring and transmits the spring's biasing force to the piston, and the area of ​​a first end face of the lever, including a first contact portion of the lever that contacts the piston, may be smaller than the area of ​​a second end face of the piston, including a second contact portion of the piston that contacts the lever. According to this configuration, it is possible to prevent heat from the piston from being transferred to the spring via the lever, thereby preventing a decrease in the strength of the spring due to the influence of heat.

[0067] (9) In the above embodiment, the opening / closing mechanism may have a piston, at least a portion of which is provided within the flow path, that opens and closes the discharge port, and a lever that contacts the spring and transmits the spring force to the piston, and the thermal conductivity of the lever may be lower than the thermal conductivity of the piston. According to this configuration, it is possible to prevent heat from the piston from being transferred to the spring via the lever, thereby preventing a decrease in the strength of the spring due to the influence of heat. [Explanation of symbols]

[0068] 10...injection molding apparatus, 20...injection unit, 21...plasticizing section, 22...suction delivery section, 23...nozzle, 24...discharge port, 30...mold clamping device, 31...mold drive section, 32...ball screw, 40...control section, 50...hopper, 110...flat screw, 111...screw case, 112...drive motor, 119...drive shaft, 121...groove forming surface, 122...center section, 123...groove, 124...material inlet, 125...convex rib section, 130...barrel, 131...communicating hole, 132...check valve, 133...opposing surface, 134...guide groove, 135...recess, 139...barrel case, 140...first heating section, 151...cylinder, 152...plunger, 153...plunger drive unit, 170...flow path, 201...first hole, 210...opening / closing mechanism, 220...piston, 221...second end surface, 230, 230b, 230c...levers, 231...groove, 232...first end surface, 240, 240b, 240c...spring, 241...first coil portion, 242...second coil portion, 243...first arm portion, 244...second arm portion, 245...third arm portion, 250...shaft member, 260...second heating unit, 270...insulating member, 280...cooling unit, 400...forming die, 401...fixed die, 402...movable die, AX...axis of spring, BX...axis of shaft member, RX...center axis

Claims

1. a plasticizing unit that plasticizes the material to generate a modeling material; a nozzle communicating with the plasticizing unit and discharging the modeling material; a mold clamping device that opens and closes a molding die into which the molding material is discharged from the nozzle, The nozzle is a flow path through which the building material flows; a discharge port communicating with the flow path and discharging the modeling material; an opening / closing mechanism, at least a portion of which is located within the flow path, for opening and closing the discharge port; a spring that applies a biasing force to the opening and closing mechanism; At least a portion of the spring is supported by the plasticized portion. Injection molding equipment.

2. 2. The injection molding apparatus according to claim 1, The spring is a torsion spring, The axis of the spring is located closer to the plasticizing section than the boundary between the plasticizing section and the nozzle. Injection molding equipment.

3. 2. The injection molding apparatus according to claim 1, The plasticized portion has a recess, The spring is located in the recess. Injection molding equipment.

4. 2. The injection molding apparatus according to claim 1, The plasticizing section comprises: a first heating section that heats the modeling material in the plasticizing section; a heat insulating member provided between the spring and the first heating unit, Injection molding equipment.

5. 2. The injection molding apparatus according to claim 1, The nozzle has a second heating section that heats the modeling material in the flow path, A space is provided between the spring and the second heating unit. Injection molding equipment.

6. 2. The injection molding apparatus according to claim 1, The plasticizing unit has a first heating unit that heats the modeling material in the plasticizing unit, The spring is located in a region that does not overlap with the first heating section in a direction in which the plasticizing section and the nozzle are aligned. Injection molding equipment.

7. 2. The injection molding apparatus according to claim 1, The plasticizing section comprises: a first heating section that heats the modeling material in the plasticizing section; a cooling section that cools the plasticizing section, a distance between the spring and the cooling unit is shorter than a distance between the spring and the first heating unit; Injection molding equipment.

8. 2. The injection molding apparatus according to claim 1, The opening and closing mechanism includes: a piston, at least a portion of which is provided within the flow path, for opening and closing the discharge port; a lever that contacts the spring and transmits the biasing force of the spring to the piston, an area of ​​a first end face of the lever including a first contact portion of the lever that contacts the piston is smaller than an area of ​​a second end face of the piston that includes a second contact portion of the piston that contacts the lever; Injection molding equipment.

9. 2. The injection molding apparatus according to claim 1, The opening and closing mechanism includes: a piston, at least a portion of which is provided within the flow path, for opening and closing the discharge port; a lever that contacts the spring and transmits the biasing force of the spring to the piston, The thermal conductivity of the lever is lower than the thermal conductivity of the piston. Injection molding equipment.

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