Injection molding device

Abstract

To prevent molding material from adhering to a nozzle when the nozzle is separated from a mold.SOLUTION: An injection molding device comprises: a fixing part to which a mold having a fixed mold and a movable mold is detachably attached; an injection part which injects molding material; and a moving part which moves the injection part relative to the fixed mold mounted on the fixing part. The injection part includes: a nozzle for injecting the molding material; and an injection amount adjustment mechanism for adjusting an injection amount of the molding material. The injection molding device further comprises a control part for controlling the moving part, the injection amount adjustment mechanism, and a heater for heating the mold. The control part executes: a first control which brings the nozzle into contact with the fixed mold and injects the molding material into a cavity of the mold with the mold mounted to the fixing part and the mold heated; and a second control which controls the moving part to separate the nozzle from the fixed mold after a predetermined time has elapsed since the first control is completed.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Patent Document 1 discloses a molding method having a filling step of filling a cavity with a thermosetting molding material from a nozzle, and a hardening step of hardening the filled molding material. For example, in the hardening step, the molding material is hardened by heating it in a state where the nozzle is separated from the molding material supply port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 093265 Summary of the Invention [Problem to be solved by the invention]

[0004] When the nozzle was separated from the mold immediately after the molding material was injected into the cavity, the uncured molding material sometimes adhered to the nozzle and became stringy. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided an injection molding apparatus, which comprises a fixed mold having a gate opening formed therein and a movable mold configured to be clamped to the fixed mold, a fixed part to which a molding mold having a cavity defined by the fixed mold and the movable mold can be attached and detached, an injection part that injects a molding material containing a thermosetting material and a polymerization initiator that initiates a polymerization reaction of the thermosetting material, and a moving part that moves the injection part relative to the fixed mold attached to the fixed part, the injection part having a nozzle opening, a nozzle that injects the molding material from the nozzle opening, and an injection amount adjustment mechanism that adjusts the injection amount of the molding material from the nozzle opening, and at least one of the fixed part and the molding mold is provided. has a heater for heating the mold, and the injection molding apparatus further includes a control unit for controlling the moving unit, the injection amount adjustment mechanism, and the heater, and the control unit executes a first control in which, with the mold attached to the fixed unit, the control unit controls the heater to heat the mold, and, with the mold attached to the fixed unit, the control unit controls the moving unit to bring the nozzle into contact with the fixed mold and the injection amount adjustment mechanism to inject the molding material from the nozzle opening through the gate opening into the cavity, and a second control in which, after a predetermined time has elapsed since completion of the first control, the control unit controls the moving unit to move the nozzle away from the fixed mold. [Brief description of the drawings]

[0006] [Figure 1] FIG. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a pump unit. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of an injection unit. [Figure 4] FIG. 4 is a perspective view showing a part of the fixed mold cut along a plane parallel to the X direction and the Z direction. [Diagram 5] An enlarged view of the nozzle shown in Figure 3. [Figure 6] FIG. 13 is a diagram showing a state in which the injection part has been moved to a position where the nozzle and the fixed mold are in contact with each other. [Figure 7] 3 is a process diagram of a molding process performed by an injection molding device. [Figure 8] FIG. 2 is a diagram showing a fixed mold near a gate opening with a cavity filled with molding material. [Figure 9] FIG. 13 is a diagram showing an example of a shutoff pin whose end on the nozzle opening side is a flat surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] A. First embodiment: FIG. 1 is a perspective view of an injection molding apparatus 10. FIG. 1 shows arrows representing mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to a horizontal plane. The Z direction is parallel to the vertical direction. The X, Y, and Z directions in FIG. 1 and the X, Y, and Z directions in other figures indicate the same direction. 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 "-". The +Z direction is also called the upward direction, and the -Z direction is also called the downward direction.

[0008] The injection molding apparatus 10 molds a molded product by injecting a two-component thermosetting material into a mold attached to the injection molding apparatus 10. The injection molding apparatus 10 includes a pump unit 100, an injection unit 200, and a control unit 500. The pump unit 100 is housed inside a first housing 20 having a door 21. The injection unit 200 is housed inside a second housing 30 having a door 31.

[0009] The control unit 500 is configured by a computer having one or more processors, a memory, and an input / output interface for inputting and outputting signals from and to the outside. The control unit 500 performs various functions, such as a function for executing a process for molding a molded product, by the processor executing a program or command loaded onto the main storage device. Note that the control unit 500 may be realized by a configuration combining a plurality of circuits for realizing at least a part of each function, instead of being configured by a computer.

[0010] 2 is a diagram showing a schematic configuration of the pump unit 100. The pump unit 100 mixes a base agent and a curing agent of a two-component thermosetting material and supplies the mixture to the injection unit 200. The pump unit 100 includes a first tank 110, a first pump 111, a second tank 120, a second pump 121, and a mixer 130.

[0011] The first tank 110 stores a first liquid. The first liquid contains a base material of a two-liquid type thermosetting material. The first liquid contains, for example, a silicone polymer that is a base material of a two-liquid type silicone rubber.

[0012] The first pump 111 is connected to the first tank 110. The first pump 111 pumps the first liquid stored in the first tank 110 to the mixing section 130. The first pump 111 is configured, for example, as a screw pump. The first pump 111 is driven under the control of the control section 500. The first liquid discharged from the first pump 111 is supplied to the mixing section 130 via a first pipe 112 connecting the first pump 111 and the mixing section 130. It is preferable that the first pump 111 can discharge the first liquid at a fixed amount to the mixing section 130 and can suppress pulsating flow of the first liquid. The first pump 111 may be configured as a positive displacement pump other than a screw pump such as a gear pump, or may be configured as a turbo pump.

[0013] The second tank 120 stores a second liquid. The second liquid contains a polymerization initiator that starts a polymerization reaction of the two-part thermosetting material. The polymerization reaction of the two-part thermosetting material can be started by combining predetermined amounts of the first liquid and the second liquid.

[0014] The second pump 121 is connected to the second tank 120. The second pump 121 pumps the second liquid stored in the second tank 120 to the mixing section 130. The second pump 121 is configured, for example, as a screw pump. The second pump 121 is driven under the control of the control section 500. The second liquid discharged from the second pump 121 is supplied to the mixing section 130 via a second pipe 122 connecting the second pump 121 and the mixing section 130. It is preferable that the second pump 121 can discharge the second liquid to the mixing section 130 at a fixed amount and can suppress the pulsating flow of the second liquid. The second pump 121 may be configured as a positive displacement pump other than a screw pump such as a gear pump, or may be configured as a turbo pump.

[0015] The mixing section 130 mixes the first liquid and the second liquid and supplies the mixed liquid to the injection unit 200. In this embodiment, the mixing section 130 is configured as a static mixer. The mixing section 130 includes a mixing cylinder 131 and a stirring member 132 provided inside the mixing cylinder 131. The mixing section 130 may be configured as a dynamic mixer.

[0016] The mixing cylinder 131 is a cylindrical member. The stirring member 132 is composed of a plurality of mixing elements connected to each other. The plurality of mixing elements are arranged side by side from one end of the mixing cylinder 131 to the other end. Each mixing element has a shape obtained by twisting a rectangular plate 180 degrees. The twist rotation directions of adjacent mixing elements are different from each other. Each mixing element is fixed to the inner wall surface of the mixing cylinder 131 and is stationary with respect to the mixing cylinder 131. Note that, although FIG. 2 shows the stirring member 132 having four mixing elements, the number of mixing elements of the stirring member 132 may be two, three, or five or more.

[0017] The mixing section 130 mixes the first liquid and the second liquid that flow into the mixing cylinder 131 by the dividing action, the converting action, and the reversing action from each mixing element of the stirring member 132. The dividing action is the action of dividing the flow of the fluid. The converting action is the action of moving the fluid from the central axis of the mixing cylinder 131 toward the inner wall surface, or from the inner wall surface toward the central axis. The reversing action is the action of reversing the direction of the vortex of the fluid that flows in a vortex shape around the central axis of the mixing cylinder 131. Hereinafter, the mixture of the first liquid and the second liquid is referred to as the molding material. The molding material generated in the mixing section 130 is supplied to the injection unit 200 via the third pipe 135 that connects the mixing section 130 and the injection unit 200.

[0018] 3 is a diagram showing a schematic configuration of injection unit 200. Injection unit 200 molds a molded product by injecting molding material supplied from pump unit 100 into molding die 900. Injection unit 200 includes a fixed unit 210, a mold clamping unit 220, an injection unit 230, a moving unit 240, and a detection unit 250.

[0019] The forming die 900 is attached to the fixed part 210. The fixed part 210 includes a fixed platen 211 and a movable platen 212. The fixed platen 211 and the movable platen 212 are plate-shaped members. The fixed platen 211 is fixed to the upper end side of a tie bar 213 extending in the vertical direction so that its plate surface is parallel to the horizontal direction. The movable platen 212 is disposed below the fixed platen 211 facing the fixed platen 211 so that its plate surface is parallel to the horizontal direction. The fixed platen 901 of the forming die 900 is attached to the fixed platen 211, and the movable platen 212 is attached to the movable platen 212. The fixed platen 901 and the movable platen 212 are attached to the fixed platen 211 and the movable platen 212, respectively, by bolts or clamp mechanisms.

[0020] The mold clamping unit 220 opens and closes the molding die 900 attached to the fixed unit 210. The mold clamping unit 220 rotates the ball screw 221 by driving a motor (not shown) under the control of the control unit 500, and moves the movable platen 212 coupled to the ball screw 221 along the tie bars 213. The molding die 900 attached to the fixed unit 210 is opened and closed as the movable platen 212 moves in the +Z direction to clamp the molding die 900, and the movable platen 212 moves in the -Z direction to open the molding die 900. As the molding die 900 is clamped, a cavity Cv is defined by the fixed die 901 and the movable die 902. The cavity Cv is a space having a shape corresponding to the shape of the molded product.

[0021] In this embodiment, the molding die 900 has a heater 903 for heating the molding die 900 to harden the molding material filled in the cavity Cv. The temperature of the heater 903 is controlled by the control unit 500. The molding die 900 may be made of metal, resin, or ceramic. The metallic molding die 900 is also called a metal mold.

[0022] 4 is a perspective view showing a part of the fixed mold 901 cut along a plane parallel to the X and Z directions. The fixed mold 901 has a gate opening 904, which is a hole that passes through the fixed mold 901 in the vertical direction. The molding material is filled into the cavity Cv through the gate opening 904. The fixed mold 901 is attached to the fixed part 210 so that the gate opening 904 faces a nozzle opening 321 of a nozzle 320, which will be described later, in the vertical direction.

[0023] 3 injects the molding material supplied from the pump unit 100. The injection part 230 is provided above the fixing part 210 and the mold clamping part 220. The injection part 230 is provided so as to be movable in the vertical direction along a guide member 242 described later. The injection part 230 includes a flow path 310, a nozzle 320, and an injection amount adjustment mechanism 330.

[0024] The flow path 310 communicates between a material supply port 311 to which the third pipe 135 of the pump unit 100 is connected and a nozzle opening 321, which will be described later. The molding material supplied from the pump unit 100 flows into the flow path 310 through the material supply port 311.

[0025] A nozzle opening 321 is formed at the tip of the nozzle 320. The nozzle 320 injects the molding material in the flow passage 310 from the nozzle opening 321.

[0026] The flow path 310 has a first flow path 312, a second flow path 313, and a third flow path 314. The first flow path 312, the second flow path 313, and the third flow path 314 are connected in series in the above-mentioned order. The first flow path 312 is a portion of the flow path 310 that extends from the nozzle opening 321 in the +Z direction. That is, the first flow path 312 extends in a direction along the vertical direction. Hereinafter, the direction along the vertical direction is also referred to as the first direction. The second flow path 313 is a portion of the flow path 310 that extends from an end of the first flow path 312 on the +Z direction side in a direction intersecting with the first direction. Hereinafter, the direction intersecting with the first direction is also referred to as the second direction. In this embodiment, the second flow path 313 extends in the +X direction from an end of the first flow path 312 on the +Z direction side. The third flow path 314 is a portion of the flow path 310 that connects the second flow path 313 and the material supply port 311 .

[0027] The injection amount adjustment mechanism 330 adjusts the amount of molding material injected from the nozzle opening 321. The injection amount adjustment mechanism 330 includes an injection cylinder 331, a plunger 332, a plunger driver 333, and a shutoff pin 334.

[0028] The injection cylinder 331 is a substantially cylindrical member connected to a portion of the flow path 310 where the second flow path 313 and the third flow path 314 are connected. The injection cylinder 331 is connected to the flow path 310 so that its axis coincides with the axis of the second flow path 313. A check valve 315 is provided in the flow path 310, upstream of the portion where the injection cylinder 331 is connected. The check valve 315 prevents the molding material from flowing back from the nozzle opening 321 side to the material supply port 311 side.

[0029] The plunger 332 is provided inside the injection cylinder 331. The plunger 332 is provided so as to be movable in the injection cylinder 331 and the second flow path 313 along the second direction. The plunger 332 is driven by the plunger driving unit 333 under the control of the control unit 500. The plunger driving unit 333 is, for example, a motor. The plunger 332 retreats inside the injection cylinder 331 and the second flow path 313 in a direction away from the first flow path 312, and sucks and measures the molding material into the injection cylinder 331. In addition, the plunger 332 advances inside the injection cylinder 331 and the second flow path 313 in a direction approaching the first flow path 312, and delivers the sucked molding material to the first flow path 312.

[0030] The shut-off pin 334 is inserted into the first flow path 312 from the end of the first flow path 312 opposite to the nozzle opening 321. The shut-off pin 334 is a cylindrical member whose diameter is smaller than the diameter of the first flow path 312, and is provided so as to be movable in the first flow path 312 along the first direction. That is, the shut-off pin 334 is provided so as to be movable in the flow path 310 along the direction in which the molding material flows. The shut-off pin 334 is driven by a shut-off pin drive unit (not shown) under the control of the control unit 500. The shut-off pin drive unit has, for example, an air cylinder, and moves the shut-off pin 334 in the first flow path 312 using compressed air. When the shut-off pin 334 moves in the −Z direction inside the first flow path 312, the nozzle opening 321 is blocked by the end of the shut-off pin 334 on the nozzle opening 321 side, and the injection of the molding material from the nozzle opening 321 is stopped. Furthermore, the shut-off pin 334 moves in the +Z direction inside the first flow passage 312, whereby the nozzle opening 321 opens and the molding material is injected from the nozzle opening 321.

[0031] Fig. 5 is an enlarged view of the nozzle 320 shown in Fig. 3. As shown in Fig. 5, the end of the shut-off pin 334 on the nozzle opening 321 side is configured in a protruding shape that does not have a flat surface. The end of the shut-off pin 334 on the nozzle opening 321 side has a pointed shape in the direction in which the molding material flows through the first flow path 312 when the molding material is injected from the nozzle opening 321. In this embodiment, the end of the shut-off pin 334 on the nozzle opening 321 side has a pointed shape toward the -Z direction.

[0032] 5, the nozzle 320 has a refrigerant flow path 322 through which a refrigerant flows. The refrigerant is, for example, water. The refrigerant flow path 322 is provided near the first flow path 312 so that the molding material in the first flow path 312 is cooled by the refrigerant flowing inside the refrigerant flow path 322. The refrigerant flow path 322 communicates with a refrigerant inlet 323 and a refrigerant outlet 324 provided on the outer surface of the nozzle 320. The refrigerant introduced into the refrigerant flow path 322 from the refrigerant inlet 323 is discharged from the refrigerant outlet 324. The refrigerant discharged from the refrigerant outlet 324 is cooled by, for example, a chiller, and circulates to the refrigerant inlet 323.

[0033] 3 is provided above the injection unit 230. The injection unit 230 is moved by the injection unit 230 relative to the fixed mold 901 fixed to the fixed unit 210. The injection unit 240 includes a movable member 241, a guide member 242, a base 243, a screw shaft 244, a ball nut 245, and a movement motor 246. The screw shaft 244 and the ball nut 245 form a ball screw.

[0034] The ejection unit 230 is fixed to the movable member 241. The movable member 241 is attached to the guide member 242, which is a columnar member extending vertically upward from the upper part of the fixed part 210, so as to be movable along the guide member 242. The base 243 is fixed to the upper end of the guide member 242. The screw shaft 244 is fixed to the base 243 so as to protrude downward from the base 243. The axial direction of the screw shaft 244 is along the vertical direction. The ball nut 245 is attached to the screw shaft 244 and is fixed to a connection member 247 fixed to the movable member 241. The movement motor 246 is driven under the control of the control unit 500 to rotate the screw shaft 244 around the axis. By the rotation of the screw shaft 244, the ball nut 245, the connection member 247, and the movable member 241 move in the vertical direction, and the ejection unit 230 moves in the vertical direction accordingly. As the ejection unit 230 moves in the -Z direction, the nozzle 320 comes into contact with the fixed mold 901 so that the nozzle opening 321 and the gate opening 904 communicate with each other. As the ejection unit 230 moves in the +Z direction, the nozzle 320 moves away from the fixed mold 901. Fig. 6 shows a state in which the ejection unit 230 has been moved to a position where the nozzle 320 and the fixed mold 901 come into contact with each other.

[0035] The detection unit 250 detects the contact pressure between the nozzle 320 and the fixed mold 901. The detection unit 250 detects the contact pressure between the nozzle 320 and the fixed mold 901 by measuring the torque of the movement motor 246, for example.

[0036] 7 is a process diagram of the molding process performed by the injection molding apparatus 10. The molding process is a process for molding a molded product by injecting a molding material into a cavity Cv of a mold 900.

[0037] In step S10, control unit 500 controls mold clamping unit 220 to clamp molding die 900 attached to fixing unit 210.

[0038] In step S20, control unit 500 controls the temperature of heater 903 to heat molding die 900.

[0039] In step S30, the control unit 500 controls the movement unit 240 to move the injection unit 230 in the −Z direction and bring the nozzle 320 into contact with the fixed mold 901. In other words, the control unit 500 presses the nozzle 320 against the fixed mold 901.

[0040] In step S40, the control unit 500 judges whether the contact pressure detected by the detection unit 250 is equal to or greater than a predetermined value. If the contact pressure is equal to or greater than the predetermined value, step S50 is executed. If the contact pressure is not equal to or greater than the predetermined value, the control unit 500 returns the process to step S30. If the contact pressure does not become equal to or greater than the predetermined value even after a predetermined time has elapsed since the nozzle 320 and the fixed mold 901 came into contact with each other, the control unit 500 interrupts the execution of the first control, which will be described later. Furthermore, a notification unit (not shown) may notify the user that the contact pressure has not become equal to or greater than the predetermined value, or that the first control has been interrupted.

[0041] In step S50, the control unit 500 controls the injection amount adjustment mechanism 330 to inject the molding material from the nozzle opening 321 into the cavity Cv of the molding die 900 through the gate opening 904. The control unit 500 first moves the shut-off pin 334 in the +Z direction in the first flow path 312 to open the nozzle opening 321. After moving the shut-off pin 334, the control unit 500 advances the plunger 332 in the injection cylinder 331 and the second flow path 313.

[0042] In step S60, the control unit 500 controls the injection amount adjustment mechanism 330 to stop the injection of the molding material from the nozzle opening 321. The control unit 500 first moves the shutoff pin 334 in the -Z direction in the first flow path 312 to close the nozzle opening 321. After moving the shutoff pin 334, the control unit 500 causes the plunger 332 to move backward in the second flow path 313 and the injection cylinder 331. Step S60 is executed when a predetermined amount of molding material is injected into the cavity Cv and the cavity Cv is filled with the molding material. Steps S20 to S60 are also referred to as a first control.

[0043] In step S70, the control unit 500 controls the moving unit 240 to move the injection unit 230 in the +Z direction to separate the nozzle 320 from the fixed mold 901. The control unit 500 separates the nozzle 320 from the fixed mold 901 at a speed faster than the speed of the nozzle 320 when the nozzle 320 contacted the fixed mold 901 in step S30. Step S70 is executed after a predetermined time has elapsed since step S60 was executed. The predetermined time is set by the user based on the thermal curing time of the thermosetting material contained in the molding material. For example, when the molding material is silicone, the predetermined time is preferably about 30 seconds to 50 seconds. Step S70 is also called the second control. That is, the second control is executed after a predetermined time has elapsed since the first control was completed.

[0044] In step S80, control unit 500 stops heating of molding die 900 by controlling the temperature of heater 903. Step S80 is executed after a predetermined time has elapsed since step S70 was executed. For example, when the molding material is silicone, the predetermined time is preferably about 50 to 60 seconds.

[0045] In step S90, the control unit 500 controls the mold clamping unit 220 to open the casting mold 900. That is, the control unit 500 separates the movable mold 902 from the fixed mold 901. It is preferable that the speed at which the movable mold 902 separates from the fixed mold 901 is 5 mm per second or less.

[0046] In step S100, the molded product is removed from the molding die 900. When the molding die 900 is opened, the molded product moves downward together with the movable die 902. The molded product is separated from the movable die 902 by the movement of an ejector pin embedded in the movable die 902 in the +Z direction. The molding process is carried out as described above.

[0047] According to the injection molding apparatus 10 in the first embodiment described above, the nozzle 320 is separated from the fixed mold 901 after a predetermined time has elapsed since the injection of the molding material into the cavity Cv is completed, so that at least a part of the molding material near the gate opening 904 hardens before the nozzle 320 is separated from the fixed mold 901. Therefore, when the nozzle 320 is separated from the fixed mold 901, it is possible to reduce the possibility that the unhardened molding material will adhere to the nozzle 320 and become stringy.

[0048] In this embodiment, the time from when the injection of the molding material into the cavity Cv is completed until the nozzle 320 is separated from the fixed mold 901 is set by the user based on the thermal curing time of the thermosetting material contained in the molding material. Therefore, the user can set an appropriate time depending on the type of thermosetting material used to mold the molded product.

[0049] Furthermore, in this embodiment, the control unit 500 presses the nozzle 320 against the fixed mold 901 until the contact pressure between the nozzle 320 and the fixed mold 901 detected by the detection unit 250 reaches a predetermined value or more. This makes it possible to prevent the molding material from being injected from the nozzle 320 in a state where the contact pressure between the nozzle 320 and the fixed mold 901 is insufficient, thereby preventing the cavity Cv from being filled with the amount of molding material required for molding a molded product.

[0050] In this embodiment, the control unit 500 suspends execution of the first control if the contact pressure does not reach a predetermined value even after a predetermined time has elapsed since the nozzle 320 and the fixed mold 901 came into contact with each other. This makes it possible to prevent the molding material from being injected from the nozzle 320 in a state where the contact pressure between the nozzle 320 and the fixed mold 901 is insufficient.

[0051] Furthermore, in this embodiment, after injection of the molding material into cavity Cv is completed, control unit 500 moves nozzle 320 away from molding die 900 at a speed faster than the speed at which nozzle 320 is brought into contact with molding die 900. Therefore, when nozzle 320 is moved away from molding die 900, it is possible to make it difficult for the molding material to adhere to nozzle 320.

[0052] In this embodiment, the speed at which the movable die 902 is separated from the fixed die 901 is preferably 5 mm per second or less. FIG. 8 shows a cross-sectional view of the fixed die 901 near the gate opening 904 in a state in which the cavity Cv is filled with the molding material 950. The molding material 950 shown in FIG. 8 is hardened. When the cavity Cv is filled with the molding material 950, a runner portion 951 is formed near the gate opening 904. When the movable die 902 is separated from the fixed die 901 at a high speed, the runner portion 951 is difficult to remove from the fixed die 901, and when the molding die 900 is opened, the molded product is likely to remain attached to the fixed die 901. In this embodiment, since the movable die 902 is separated from the fixed die 901 at a speed of 5 mm per second or less, the runner portion 951 can be easily removed from the fixed die 901 when the molding die 900 is opened. As a result, the molded product can be easily removed from the molding die 900.

[0053] In this embodiment, the plunger 332 moves along the second direction in the second flow passage 313 that extends in the second direction intersecting the vertical direction. Therefore, the vertical size of the injection section 230 can be made smaller than when the plunger 332 moves in the vertical direction. Therefore, the injection molding apparatus 10 can be made smaller in size in the vertical direction.

[0054] In this embodiment, the end of the shut-off pin 334 on the nozzle opening 321 side is a protrusion shape that does not have a flat surface. FIG. 9 shows an example of a shut-off pin 334b ​​whose end on the nozzle opening 321 side is a flat surface. When the shut-off pin 334b ​​moves in the -Z direction, the molding material located below the shut-off pin 334b ​​is pushed out from the nozzle opening 321. As shown in FIG. 5, when the end of the shut-off pin 334 is a protrusion shape, the shut-off pin 334 moves in the -Z direction so as to push aside the molding material located below the shut-off pin 334. Therefore, in this embodiment, when the injection of the molding material from the nozzle opening 321 is stopped by moving the shut-off pin 334 downward, the amount of molding material pushed out from the nozzle opening 321 can be reduced.

[0055] Furthermore, in this embodiment, heating of the molding die 900 is stopped after a predetermined time has elapsed since the nozzle 320 was separated from the fixed die 901. That is, the nozzle 320 is separated from the fixed die 901 before the molding material filled in the cavity Cv is completely hardened. Therefore, it is possible to make the molding material in the flow path less likely to harden, compared to a case in which the nozzle 320 is in contact with the fixed die 901 until the molding material is completely hardened.

[0056] Moreover, in this embodiment, the nozzle 320 has a coolant flow path 322. Therefore, while the nozzle 320 and the fixed mold 901 are in contact with each other, the molding material in the nozzle 320 is less likely to harden.

[0057] Moreover, in this embodiment, the ejection unit 230 includes a shutoff pin 334. Therefore, the thickness of the fixed mold 901 in the vertical direction can be made thinner than when the fixed mold 901 is provided with a shutoff mechanism.

[0058] B. Other embodiments: (B-1) In the above embodiment, the forming mold 900 has the heater 903. Alternatively, the fixing part 210 may have a heater for heating the forming mold 900.

[0059] (B-2) In the above embodiment, the injection unit 200 includes the detection unit 250. However, the injection unit 200 does not necessarily need to include the detection unit 250.

[0060] (B-3) In the above embodiment, in step S70 of the molding process, the control unit 500 separates the nozzle 320 from the fixed mold 901 at a speed faster than the speed of the nozzle 320 when the nozzle 320 contacted the fixed mold 901 in step S30. In contrast, the control unit 500 may separate the nozzle 320 from the fixed mold 901 at a speed equal to the speed of the nozzle 320 when the nozzle 320 contacted the fixed mold 901 in step S30, or at a speed slower than the above-mentioned speed.

[0061] (B-4) In the above embodiment, the second flow path 313 extends in the direction along the X direction. However, the direction in which the second flow path 313 extends is not limited to the direction along the X direction. The second flow path 313 may extend in any direction intersecting the vertical direction.

[0062] (B-5) In the above embodiment, the end of the shut-off pin 334 on the nozzle opening 321 side is a protruding shape that does not have a flat surface. In contrast, the end of the shut-off pin 334 on the nozzle opening 321 side does not have to be a protruding shape and may have a flat surface.

[0063] C. 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.

[0064] (1) According to one aspect of the present disclosure, there is provided an injection molding apparatus, comprising: a fixed part having a fixed mold with a gate opening formed therein, and a movable mold configured to be clamped to the fixed mold, to which a molding mold in which a cavity is defined by the fixed mold and the movable mold can be detachably attached; an injection part that injects a molding material containing a thermosetting material and a polymerization initiator that initiates a polymerization reaction of the thermosetting material; and a moving part that moves the injection part relative to the fixed mold attached to the fixed part, the injection part having a nozzle opening, a nozzle that injects the molding material from the nozzle opening, and an injection amount adjustment mechanism that adjusts the amount of the molding material injected from the nozzle opening; and a mechanism that adjusts the amount of the molding material injected from the nozzle opening, and at least one of the fixed part and the molding mold is movable. has a heater for heating the mold, and the injection molding apparatus further includes a control unit for controlling the moving unit, the injection amount adjustment mechanism, and the heater, and the control unit executes a first control in which, with the mold attached to the fixed unit, the control unit controls the heater to heat the mold, and, with the mold attached to the fixed unit, the control unit controls the moving unit to bring the nozzle into contact with the fixed mold and the injection amount adjustment mechanism to inject the molding material from the nozzle opening through the gate opening into the cavity, and a second control in which, after a predetermined time has elapsed since completion of the first control, the control unit controls the moving unit to move the nozzle away from the fixed mold. According to this configuration, at least a portion of the molding material near the gate opening hardens before the nozzle is separated from the fixed mold, thereby reducing the possibility of the molding material adhering to the nozzle and becoming stringy when the nozzle is separated from the fixed mold.

[0065] (2) In the above embodiment, a detection unit is provided that detects the contact pressure between the nozzle and the fixed mold, and in the first control, the control unit may press the nozzle against the fixed mold until the contact pressure detected by the detection unit becomes equal to or greater than a predetermined value before the molding material is injected into the cavity. According to this embodiment, it is possible to prevent the molding material from being injected from the nozzle when the contact pressure between the nozzle and the fixed mold is insufficient, thereby preventing the cavity from being filled with the amount of molding material required to mold the molded product.

[0066] (3) In the above embodiment, the control unit may interrupt execution of the first control if the contact pressure does not become equal to or greater than a predetermined value even after a predetermined time has elapsed since the nozzle and the fixed mold came into contact with each other. According to this embodiment, it is possible to prevent the molding material from being injected from the nozzle in a state where the contact pressure between the nozzle and the fixed mold is insufficient.

[0067] (4) In the above aspect, the control unit may, in the second control, separate the nozzle from the fixed mold at a speed faster than a speed at which the nozzle is brought into contact with the fixed mold in the first control. According to this embodiment, when the nozzle is separated from the fixed mold, the possibility that the molding material will adhere to the nozzle and become stringy can be reduced.

[0068] (5) In the above embodiment, after executing the second control, the control unit may separate the movable mold from the fixed mold at a speed of 5 mm per second or less. According to this embodiment, when the movable die is separated from the fixed die, the molded product can be easily removed from the fixed die.

[0069] (6) In the above embodiment, the injection section may have a flow path through which the molding material flows, the flow path having a first flow path extending in a first direction that is a direction along the vertical direction and a second flow path extending in a second direction that is a direction intersecting the first direction, and the injection amount adjustment mechanism may include a shutoff pin that moves within the first flow path along the first direction, and a plunger that moves within the second flow path along the second direction. According to this embodiment, the injection molding apparatus can be made smaller in size in the vertical direction than in a case where the plunger moves in a vertical direction.

[0070] (7) In the above embodiment, the injection amount adjustment mechanism may include a shutoff pin that moves along the direction in which the molding material flows within the flow path through which the molding material flows, and the end of the shutoff pin on the nozzle opening side may have a protrusion shape that does not have a flat surface. According to this configuration, the amount of molding material extruded from the nozzle opening when the shutoff pin is moved in a direction approaching the nozzle opening can be reduced, compared to when the end of the shutoff pin on the nozzle opening side is flat. [Explanation of symbols]

[0071] Reference Signs List 10... injection molding apparatus, 20... first housing, 21... door, 30... second housing, 31... door, 100... pump unit, 110... first tank, 111... first pump, 112... first piping, 120... second tank, 121... second pump, 122... second piping, 130... mixing section, 131... mixing cylinder, 132... stirring member, 135... third piping, 200... injection unit, 210... fixed section, 211... fixed platen, 212... movable platen, 213... tie bar, 220... mold clamping section, 221... ball screw, 230... injection section, 240... moving section, 241... moving member, 242... guide member, 243... base, 244... screw shaft, 245... ball nut, 246... moving motor motor, 247...connecting member, 250...detection unit, 310...flow path, 311...material supply port, 312...first flow path, 313...second flow path, 314...third flow path, 315...check valve, 320...nozzle, 321...nozzle opening, 322...refrigerant flow path, 323...refrigerant inlet, 324...refrigerant outlet, 330...injection amount adjustment mechanism, 331...injection cylinder, 332...plunger, 333...plunger drive unit, 334...shutoff pin, 334b...shutoff pin, 500...control unit, 900...molding mold, 901...fixed mold, 902...movable mold, 903...heater, 904...gate opening, 950...molding material, 951...runner unit, Cv...cavity

Claims

1. 1. An injection molding apparatus comprising: a fixed part to which a molding die having a cavity defined by the fixed die and a movable die configured to be clamped to the fixed die can be detachably attached; an injection unit that injects a molding material including a thermosetting material and a polymerization initiator that initiates a polymerization reaction of the thermosetting material; a moving unit that moves the injection unit relative to the fixed mold attached to the fixed unit, The injection unit includes: a nozzle having a nozzle opening and configured to inject the molding material from the nozzle opening; an injection amount adjustment mechanism that adjusts the injection amount of the molding material from the nozzle opening, At least one of the fixing unit and the molding die has a heater that heats the molding die, The injection molding apparatus further includes a control unit that controls the moving unit, the injection amount adjustment mechanism, and the heater, The control unit, in a state in which the molding die is attached to the fixing unit, a first control for controlling the heater to heat the molding die, controlling the moving part to bring the nozzle into contact with the fixed die, and controlling the injection amount adjustment mechanism to inject the molding material from the nozzle opening through the gate opening into the cavity; and executing a second control for controlling the moving unit to move the nozzle away from the fixed mold after a predetermined time has elapsed since the first control was completed. Injection molding equipment.

2. 2. The injection molding apparatus of claim 1, a detection unit that detects a contact pressure between the nozzle and the fixed mold, In the first control, the control unit presses the nozzle against the fixed mold until the contact pressure detected by the detection unit becomes equal to or greater than a predetermined value before the molding material is injected into the cavity. Injection molding equipment.

3. 3. The injection molding apparatus according to claim 2, the control unit interrupts execution of the first control when the contact pressure does not become equal to or greater than a predetermined value even after a predetermined time has elapsed since the nozzle and the stationary mold came into contact with each other. Injection molding equipment.

4. 2. The injection molding apparatus of claim 1, the control unit, in the second control, causes the nozzle to separate from the stationary mold at a speed faster than a speed at which the nozzle is brought into contact with the stationary mold in the first control. Injection molding equipment.

5. 2. The injection molding apparatus of claim 1, After executing the second control, the control unit separates the movable die from the fixed die at a speed of 5 mm per second or less. Injection molding equipment.

6. 2. The injection molding apparatus of claim 1, The injection section has a flow path through which the molding material flows, The flow path is A first flow path extending in a first direction that is a direction along a vertical direction; A second flow path extending in a second direction that intersects the first direction, The injection amount adjustment mechanism includes: a shutoff pin that moves in the first direction within the first flow path; a plunger that moves in the second direction within the second flow path, Injection molding equipment.

7. 2. The injection molding apparatus of claim 1, the injection amount adjustment mechanism includes a shutoff pin that moves along a flow direction of the molding material within a flow path through which the molding material flows, The end of the shutoff pin on the nozzle opening side is a protrusion shape that does not have a flat surface. Injection molding equipment.

Images