Injection molding machine and injection molding machine system

Abstract

The invention relates to an injection molding machine and an injection molding machine system, which can prevent the reverse flow of molten resin and stably inject a molding material. An injection molding machine (1) includes a first reservoir cylinder (10) and a second reservoir cylinder (20) to which molten resin is supplied, a first reservoir plunger (12) that extrudes the molten resin from the first reservoir cylinder (10), a second reservoir plunger (22) that extrudes the molten resin from the second reservoir cylinder (20), and an injection cylinder (30) to which the molten resin from the first reservoir cylinder (10) or the second reservoir cylinder (20) is supplied. When the molten resin is supplied from the first reservoir cylinder (10) to the injection cylinder (30), the molten resin is supplied to the inside of the second reservoir cylinder (20). On the other hand, when the molten resin is supplied from the second reservoir cylinder (20) to the injection cylinder (30), the molten resin is supplied to the inside of the first reservoir cylinder (10).

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2023-173511 filed on October 5, 2023. The entire contents of the Japanese Patent Application are incorporated herein by reference.

[0002] The invention relates to an injection molding machine and an injection molding machine system. Background Art

[0003] In the past, there is known an injection molding machine that uses two cylinders to inject molding materials into a mold device. For example, Patent Document 1 discloses an injection molding machine that includes: a reservoir cylinder to which molten resin as a molding material is supplied; and an injection cylinder to which the molten resin is supplied from the reservoir cylinder.

[0004] In this injection molding machine, a supply pipe for molten resin is connected to the front end of a reservoir cylinder, and molten resin is continuously supplied to the reservoir cylinder by a molten resin supply device on the upstream side of the supply pipe. Furthermore, the injection molding machine advances the first plunger of the reservoir cylinder, thereby delivering the supplied molten resin from the front end of the reservoir cylinder and accumulating the molten resin in the front of the internal space of the second cylinder. Then, the injection molding machine advances the second plunger of the injection cylinder, thereby injecting the molten resin accumulated in the front of the injection cylinder into the mold device.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-27158

[0006] However, in an injection molding machine that continuously supplies molten resin from a supply pipe to an reservoir cylinder, when the molten resin is sent from the reservoir cylinder to the injection cylinder, the molten resin in the reservoir cylinder may flow back toward the supply pipe. Summary of the invention

[0007] The present invention provides a technology capable of preventing molten resin from flowing back and stably performing injection molding of a material.

[0008] According to one embodiment of the present invention, an injection molding machine is provided, which includes: a first storage cylinder and a second storage cylinder, which are supplied with molten resin; a first injection component, which is arranged inside the first storage cylinder and extrude the molten resin of the first storage cylinder; a second injection component, which is arranged inside the second storage cylinder and extrude the molten resin of the second storage cylinder; and an injection cylinder, which is supplied with the molten resin of the first storage cylinder and the molten resin of the second storage cylinder, wherein, when the molten resin is supplied from the first storage cylinder to the injection cylinder, the molten resin is supplied to the inside of the second storage cylinder, and on the other hand, when the molten resin is supplied from the second storage cylinder to the injection cylinder, the molten resin is supplied to the inside of the first storage cylinder.

[0009] Effects of the Invention

[0010] According to one embodiment, the molten resin is prevented from flowing back, and the material can be injection-molded stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a side view showing the overall structure of the injection molding machine system according to the embodiment.

[0012] Figure 2 It is a cross-sectional view schematically showing an injection device of an injection molding machine according to the embodiment.

[0013] Figure 3 This is a flowchart showing the operation of the injection device when viewed with the injection cylinder as a reference.

[0014] Figure 4 (A) is a cross-sectional view showing the operation of the metering process of the injection cylinder. Figure 4 (B) is a diagram showing the operation of the injection cylinder during the injection process.

[0015] Figure 5 (A) is a cross-sectional view showing the operation of another reservoir cylinder in the metering process of the injection cylinder. Figure 5 (B) is a diagram showing the discharge operation of the molten resin.

[0016] Figure 6 This is a first flow chart showing control of the first accumulator cylinder and the second accumulator cylinder and control of the injection cylinder.

[0017] Figure 7 This is a second flow chart showing the control of the first accumulator cylinder and the second accumulator cylinder and the control of the injection cylinder.

[0018] Explanation of symbols

[0019] 1-injection molding machine, 10-first reservoir cylinder, 12-first reservoir plunger, 20-second reservoir cylinder, 22-second reservoir plunger, 30-injection cylinder, 32-injection plunger, 50-injection switching valve, 60-reservoir switching valve, 70-discharge portion. DETAILED DESCRIPTION

[0020] Hereinafter, the mode for implementing the present invention will be described with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals and repeated descriptions are sometimes omitted.

[0021] <Injection molding machine system S>

[0022] Figure 1 2 is a side view showing the overall structure of the injection molding machine system S according to the embodiment. Figure 1 As shown, the injection molding machine system S according to the embodiment includes an injection molding machine 1 and a molten resin supply device 6 .

[0023] The injection molding machine 1 includes: a mold clamping device 2 for opening and closing a mold device 2a housed inside a housing; and an injection device 3 for injecting a molding material into a cavity space of the mold device 2a. In addition, the injection molding machine 1 includes: an ejection device (not shown) for ejecting a molded product molded by the mold device 2a, a moving device (not shown) for moving the injection device 3 forward and backward relative to the mold device 2a, and a frame 5 for supporting various components of the injection molding machine 1. In addition, the injection molding machine 1 includes a controller 4 for controlling various components of the injection molding machine 1.

[0024] Under the control of the controller 4, the mold clamping device 2 sequentially performs a mold closing process for bringing the movable mold and the fixed mold of the mold device 2a into contact, a pressurizing process for increasing the mold clamping force, a mold clamping process for maintaining the mold clamping force, a decompressing process for reducing the mold clamping force, and a mold opening process for separating the movable mold from the fixed mold.

[0025] The injection device 3 performs a metering process, a filling process, a pressure-maintaining process, etc. under the control of the controller 4. Hereinafter, the filling process and the pressure-maintaining process are collectively referred to as an injection process. The operation of the injection device 3 will be described in detail later.

[0026] The ejector device performs an ejection process according to a control command from the controller 4. In this ejection process, an ejector rod (not shown) is advanced from a standby position to an ejection position to eject the molded product, and then the ejector rod is retracted to the original standby position.

[0027] The moving device moves the injection device 3 forward and backward relative to the mold device 2a. When the injection device 3 is moved forward toward the mold device 2a, the injection device 3 is pressed against the fixed mold of the mold device 2a. When the injection device 3 is moved backward, the injection device 3 is separated from the fixed mold of the mold device 2a.

[0028] The controller 4 repeatedly manufactures the molded product by repeatedly performing the above-mentioned metering process, mold closing process, pressure increasing process, mold closing process, filling process, pressure holding process, cooling process, decompression process, mold opening process and ejection process. A series of actions for obtaining a molded product (for example, actions from the start of a metering process to the start of the next metering process) is also called a molding cycle. In addition, the time required for one molding cycle is also called a molding cycle time.

[0029] For example, a molding cycle sequentially performs metering process, mold closing process, pressure increasing process, mold closing process, filling process, pressure holding process, cooling process, decompression process, mold opening process and ejection process. The order here is the order in which each process starts. The filling process, pressure holding process and cooling process are performed during the mold closing process. The start of the mold closing process can coincide with the start of the filling process. The end of the decompression process coincides with the start of the mold opening process.

[0030] In addition, multiple processes can be performed simultaneously for the purpose of shortening the molding cycle time. For example, the metering process can be performed during the cooling process of the previous molding cycle, or during the mold closing process. In this case, the mold closing process can be performed at the beginning of the molding cycle. In addition, the filling process can be started during the mold closing process. In addition, the ejection process can be started during the mold opening process. The mold opening process can be started during the metering process.

[0031] Furthermore, a primary molding cycle may include processes other than the metering process, the mold closing process, the pressure increasing process, the mold clamping process, the filling process, the pressure holding process, the cooling process, the decompression process, the mold opening process, and the ejection process.

[0032] On the other hand, the molten resin supply device 6 melts a resin as an example of a molding material to generate a molten resin, and continuously supplies the molten resin to the injection device 3 of the injection molding machine 1. As an example of the resin, polyethylene terephthalate resin (PET resin) can be cited. The molten resin supply device 6 involved in the embodiment directly melts the material obtained by forming a molded product of PET resin such as a plastic bottle into a thin sheet (sheet) (without making it into a granular form) to generate a molten resin. As a result, the process of cooling and crystallizing the molten resin to make it granular and the processes of drying, heating, melting, etc. of the granular resin can be omitted, thereby reducing the energy consumption in the overall injection molding. In addition, the molten resin supply device 6 can also melt the granular resin to generate a molten resin.

[0033] The molten resin supply device 6 includes a drying and squeezing device 7 that dries the sheet-shaped PET resin and squeezing it to the downstream side, and a melting and squeezing device 8 that melts the PET resin on the downstream side of the drying and squeezing device 7 and squeezing it to the downstream side. In addition, the molten resin supply device 6 includes a supply pipe 9 that connects the melting and squeezing device 8 and the injection device 3 and supplies the molten resin of the melting and squeezing device 8 to the injection device 3. The supply pipe 9 may include, for example, a heat insulating member covering the pipe, a heater that keeps the molten resin flowing in the pipe warm, and the like.

[0034] In addition, Figure 1 In the figure, a structure in which one injection molding machine 1 is connected to the supply piping 9 is shown, but the present invention is not limited thereto, and the injection molding machine system S may also be a structure in which a plurality of injection molding machines 1 are connected to the supply piping 9. Figure 1 , the figure shows a structure in which one molten resin supply device 6 is connected to the supply pipe 9 , but the present invention is not limited thereto, and the injection molding machine system S may also be a structure in which a plurality of molten resin supply devices 6 are connected to the supply pipe 9 .

[0035] The molten resin supply device 6 continuously operates the dry pressure-feeding device 7 and the melt pressure-feeding device 8 to continuously pressure-feed the molten molten resin to the injection device 3 via the supply pipe 9. At this time, the injection molding machine system S is configured such that the molten resin supply device 6 continuously supplies the molten resin, while the injection molding machine 1 intermittently injects the molten resin. Therefore, for example, the injection molding machine system S has the following problem: even if the injection molding machine 1 stops due to an error or the like, it is difficult to immediately stop the supply of the molten resin from the molten resin supply device 6.

[0036] <Structure of injection device 3 according to embodiment>

[0037] Therefore, the injection molding machine system S according to the embodiment is configured such that the injection device 3 to which the molten resin is supplied receives the molten resin supplied continuously and injects the molten resin intermittently. Figure 2 The structure of the injection device 3 will be described in detail. Figure 2 It is a cross-sectional view schematically showing the injection device 3 of the injection molding machine 1 according to the embodiment.

[0038] The injection device 3 of the injection molding machine 1 uses three cylinders to inject molten resin as a molding material into the mold device 2a (see also Figure 4(A)). Specifically, the injection device 3 includes: a first storage cylinder 10 and a second storage cylinder 20 as storage cylinders for temporarily storing molten resin; and an injection cylinder 30 for injecting molten resin into the mold device 2a. A first storage cylinder plunger (first injection component) 12 capable of advancing and retreating relative to the first storage cylinder 10 is provided inside the first storage cylinder 10. A second storage cylinder plunger (second injection component) 22 capable of advancing and retreating relative to the second storage cylinder 20 is provided inside the second storage cylinder 20. An injection plunger (third injection component) 32 capable of advancing and retreating relative to the injection cylinder 30 is provided inside the injection cylinder 30.

[0039] The injection device 3 also includes a first injection component driving unit 15 that drives the first reservoir plunger 12, a second injection component driving unit 25 that drives the second reservoir plunger 22, and a third injection component driving unit 35 that drives the injection plunger 32. The injection device 3 also includes an injection nozzle 40, an injection switching valve 50, a reservoir switching valve 60, a discharge unit 70, and a control unit 80.

[0040] The first reservoir cylinder 10 is formed into a cylindrical shape extending in the horizontal direction. A reservoir switching valve 60 is connected to the front end of the first reservoir cylinder 10, and a first injection component driving unit 15 is provided at the base end of the first reservoir cylinder 10. The molten resin is supplied from the front end to the internal space of the first reservoir cylinder 10 via the reservoir switching valve 60. A heating device (not shown) may be provided on the cylinder wall constituting the first reservoir cylinder 10, and the heating device keeps or heats the molten resin supplied to the internal space.

[0041] The first reservoir plunger 12 is formed as a solid rod member, and extrude the molten resin supplied to the internal space by advancing in the internal space of the first reservoir cylinder 10. The axis of the first reservoir plunger 12 is coaxial with the axis of the first reservoir cylinder 10. The outer peripheral surface of the first reservoir plunger 12 is a smooth curved surface, and its outer diameter is set to be the same as the inner diameter of the first reservoir cylinder 10 (or slightly smaller than the inner diameter of the first reservoir cylinder 10). As a result, the first reservoir plunger 12 advances and retreats (slides) relative to the first reservoir cylinder 10, thereby moving the molten resin in the internal space of the first reservoir cylinder 10.

[0042] The first injection component driving unit 15 closes the base end of the first reservoir cylinder 10 and holds the base end of the first reservoir plunger 12. The first injection component driving unit 15 includes an advance / retract motor 16, an encoder 17, and a pressure detection unit 18, for example.

[0043] The advance / retract motor 16 advances / retracts the first reservoir plunger 12 along the axis of the first reservoir cylinder 10. A motion conversion mechanism is provided between the first reservoir plunger 12 and the advance / retract motor 16 to convert the rotational motion of the advance / retract motor 16 into the linear motion of the first reservoir plunger 12. The motion conversion mechanism may be, for example, a ball screw.

[0044] The encoder 17 detects the rotation of the forward / retract motor 16 and sends the detection signal to the control unit 80. The control unit 80 calculates the position and movement speed of the first reservoir plunger 12 based on the detection signal of the encoder 17, and controls the operation of the first reservoir plunger 12 using the calculation results.

[0045] The pressure detection unit 18 is provided on the transmission path between the advance / retract motor 16 and the first reservoir plunger 12, and detects the force transmitted between the advance / retract motor 16 and the first reservoir plunger 12, and sends the detection signal thereof to the control unit 80. The control unit 80 calculates the pressure of the first reservoir plunger 12 based on the detection signal, and adjusts or monitors the pressure received by the first reservoir plunger 12 from the molding material (the back pressure on the first reservoir plunger 12), the pressure acting on the molding material from the first reservoir plunger 12, and the like.

[0046] Furthermore, the second reservoir cylinder 20 has the same structure as the first reservoir cylinder 10. Specifically, the second reservoir cylinder 20 is formed into a cylindrical shape extending in the horizontal direction (a direction parallel to the first reservoir cylinder 10). A reservoir switching valve 60 is connected to the front end of the second reservoir cylinder 20, and on the other hand, a second injection component driving unit 25 is provided at the base end of the second reservoir cylinder 20. The molten resin is supplied from the front end to the internal space of the second reservoir cylinder 20 via the reservoir switching valve 60. A heating device (not shown) may be provided on the cylinder wall constituting the second reservoir cylinder 20, and the heating device keeps or heats the molten resin supplied to the internal space.

[0047] The second reservoir plunger 22 is formed as a solid rod member, and extrude the molten resin supplied to the internal space by advancing in the internal space of the second reservoir cylinder 20. The axis of the second reservoir plunger 22 is arranged coaxially with the axis of the second reservoir cylinder 20. The outer peripheral surface of the second reservoir plunger 22 is a smooth curved surface, and its outer diameter is set to be the same as the inner diameter of the second reservoir cylinder 20 (or slightly smaller than the inner diameter of the second reservoir cylinder 20). Thus, the second reservoir plunger 22 advances and retreats (slides) relative to the second reservoir cylinder 20, thereby moving the molding material in the internal space of the second reservoir cylinder 20.

[0048] The second injection component driving unit 25 closes the base end of the second reservoir cylinder 20 and holds the base end of the second reservoir plunger 22. The second injection component driving unit 25 includes an advance / retract motor 26, an encoder 27, and a pressure detection unit 28, for example.

[0049] The advance / retract motor 26 advances / retracts the second reservoir plunger 22 along the axis of the second reservoir cylinder 20. A motion conversion mechanism is provided between the second reservoir plunger 22 and the advance / retract motor 26 to convert the rotational motion of the advance / retract motor 26 into the linear motion of the second reservoir plunger 22. For example, a ball screw may be used as the motion conversion mechanism.

[0050] The encoder 27 detects the rotation of the forward / retract motor 26 and sends the detection signal to the control unit 80. The control unit 80 calculates the position and movement speed of the second reservoir plunger 22 based on the detection signal of the encoder 27, and controls the operation of the second reservoir plunger 22 using the calculation results.

[0051] The pressure detection unit 28 is provided on the transmission path between the advance / retract motor 26 and the second reservoir plunger 22, and detects the force transmitted between the advance / retract motor 26 and the second reservoir plunger 22, and sends the detection signal thereof to the control unit 80. The control unit 80 calculates the pressure of the second reservoir plunger 22 based on the detection signal, and adjusts or monitors the pressure received by the second reservoir plunger 22 from the molding material (back pressure on the second reservoir plunger 22), the pressure acting on the molding material from the second reservoir plunger 22, and the like.

[0052] On the other hand, the injection cylinder 30 is formed into a cylindrical shape extending parallel to the first reservoir cylinder 10 and the second reservoir cylinder 20 (in the horizontal direction). An injection switching valve 50 is connected to the front end of the injection cylinder 30, and on the other hand, a third injection component driving unit 35 is provided at the base end of the injection cylinder 30. The molten resin is supplied to the internal space of the injection cylinder 30 from the front end side via the injection switching valve 50. A heating device (not shown) may be provided on the cylinder wall constituting the injection cylinder 30, and the heating device keeps or heats the molten resin supplied to the internal space.

[0053] The injection plunger 32 is formed as a solid rod member similar to the first reservoir plunger 12 and the second reservoir plunger 22, and extrudes the molten resin supplied to the internal space by advancing in the internal space of the injection cylinder 30. The axis of the injection plunger 32 is arranged coaxially with the axis of the injection cylinder 30. The outer peripheral surface of the injection plunger 32 is a smooth curved surface, and its outer diameter is set to be the same as the inner diameter of the injection cylinder 30 (or slightly smaller than the inner diameter of the injection cylinder 30). Thus, the injection plunger 32 advances and retreats (slides) relative to the injection cylinder 30, thereby moving the molding material in the internal space of the injection cylinder 30.

[0054] The third injection member driving unit 35 closes the base end of the injection cylinder 30 and holds the base end of the injection plunger 32. Similar to the first injection member driving unit 15, the third injection member driving unit 35 also includes an advance / retract motor 36, an encoder 37, and a pressure detector 38.

[0055] The advance / retract motor 36 advances / retracts the injection plunger 32 along the axis of the injection cylinder 30. A motion conversion mechanism is provided between the injection plunger 32 and the advance / retract motor 36 to convert the rotational motion of the advance / retract motor 36 into the linear motion of the injection plunger 32. The motion conversion mechanism may be, for example, a ball screw.

[0056] The encoder 37 detects the rotation of the forward / retract motor 36 and sends the detection signal to the control unit 80. The control unit 80 calculates the position and movement speed of the injection plunger 32 based on the detection signal of the encoder 37, and controls the operation of the injection plunger 32 using the calculation results.

[0057] The pressure detection unit 38 is provided on the transmission path between the advance / retract motor 36 and the injection plunger 32, and detects the force transmitted between the advance / retract motor 36 and the injection plunger 32, and sends the detection signal thereof to the control unit 80. The control unit 80 calculates the pressure of the injection plunger 32 based on the detected force, and adjusts or monitors the pressure received by the injection plunger 32 from the molding material (back pressure on the injection plunger 32), the pressure acting on the molding material from the injection plunger 32, and the like.

[0058] The injection nozzle 40 of the injection device 3 is provided at a position on the opposite side of the injection cylinder 30 in the injection switching valve 50, and is formed as a cylindrical body connected to the flow path (runner, etc.) of the mold device 2a. The injection nozzle 40 flows and injects the molten resin extruded from the injection cylinder 30 through the injection switching valve 50 into the mold device 2a. The mold device 2a molds a molded product by solidifying the molten resin filled into the cavity space from the injection nozzle 40.

[0059] The injection switching valve 50 is provided between the injection cylinder 30, the injection nozzle 40 and the reservoir switching valve 60, and switches the flow of the molten resin. The injection switching valve 50 corresponds to an example of an injection switching unit as a switching unit of the present invention. Specifically, in the metering process of the injection device 3, if the molten resin flows in from the reservoir switching valve 60, the injection switching valve 50 allows the molten resin to flow into the injection cylinder 30. In addition, the injection switching valve 50 performs internal switching in the injection process of the injection device 3, cuts off the communication between the injection cylinder 30 and the reservoir switching valve 60, and allows the injection cylinder 30 to communicate with the mold device 2a so that injection can be performed. Thus, the injection switching valve 50 is such that, if the molten resin flows in from the injection cylinder 30, the molten resin is injected into the mold device 2a. In addition, in the injection device 3 of the embodiment, the injection switching valve 50 and the reservoir switching valve 60 are set as different devices, but they may also be one device. The injection switching valve 50 includes a valve body 51, a valve core 52 and a valve core driving unit (not shown).

[0060] The valve body 51 is formed into a substantially rectangular parallelepiped and accommodates a valve core 52 therein. The valve body 51 has a supply connection flow path 53 communicating with the flow path of the reservoir switching valve 60, an injection cylinder connection flow path 54 communicating with the internal space of the injection cylinder 30, and a nozzle connection flow path 55 communicating with the inside of the injection nozzle 40. The injection cylinder connection flow path 54 and the nozzle connection flow path 55 extend in opposite directions to each other, for example, across the rotation center line of the valve core 52. The supply connection flow path 53 extends, for example, in a direction orthogonal to the axis connecting the injection cylinder connection flow path 54 and the nozzle connection flow path 55.

[0061] The valve core 52 is formed in a spherical shape and can rotate relative to the valve body 51. A flow path that is T-shaped when viewed in cross section is formed inside the valve core 52. Thus, the valve core 52 switches the injection switching valve 50 between the first state and the second state. In the first state, the valve core 52 connects the supply connection flow path 53 with the injection cylinder connection flow path 54 and closes the nozzle connection flow path 55. In the second state, the valve core 52 connects the injection cylinder connection flow path 54 with the nozzle connection flow path 55 and closes the supply connection flow path 53 (see also Figure 4 (B)). Thus, in the first state, the molten resin can be moved from the reservoir switching valve 60 toward the injection cylinder 30. In the second state, the molten resin can be moved from the injection cylinder 30 toward the injection nozzle 40.

[0062] The valve core driving unit switches between the first state and the second state by rotating the valve core 52 in the valve body 51. In addition, the state of the valve core 52 is not limited to the first state and the second state. For example, the valve core 52 can be in a state of closing the supply connection flow path 53, the injection cylinder connection flow path 54, and the nozzle connection flow path 55 at the same time. In addition, the valve core 52 can also be in a state of connecting the supply connection flow path 53 with the nozzle connection flow path 55 and closing the injection cylinder connection flow path 54.

[0063] The reservoir switching valve 60 is provided between the supply piping 9, the first reservoir cylinder 10, the second reservoir cylinder 20, the injection switching valve 50 and the discharge portion 70, and switches the flow of the molten resin. The reservoir switching valve 60 corresponds to an example of a reservoir switching portion as a switching portion of the present invention. Specifically, the reservoir switching valve 60 selectively flows the molten resin into either the first reservoir cylinder 10 or the second reservoir cylinder 20 when the molten resin flows in from the supply piping 9. In addition, the reservoir switching valve 60 performs internal switching in the metering process of the injection device 3, and flows the molten resin from the first reservoir cylinder 10 or the second reservoir cylinder 20, and flows the molten resin into the injection switching valve 50. The reservoir switching valve 60 includes a valve body 61, four valve cores (a supply switching valve core 62, a first reservoir valve core 63, a second reservoir valve core 64 and a discharge switching valve core 65), and a valve core driving portion (not shown).

[0064] The valve body 61 is formed into a substantially rectangular parallelepiped and accommodates the above-mentioned four valve cores. Each valve core is formed into a spherical shape and can rotate relative to the valve body 61. A flow path that is T-shaped when viewed in section is formed inside each valve core. For example, the first reservoir valve core 63, the supply conversion valve core 62 and the second reservoir valve core 64 are arranged side by side in sequence along the length direction of the valve body 61. The discharge conversion valve core 65 is arranged along the width direction of the valve body 61 at a position side by side with the supply conversion valve core 62 (middle position in the length direction).

[0065] In the valve body 61, a flow path of molten resin is provided between each valve core. Specifically, the valve body 61 has a supply flow path 62a communicating with the flow path of the supply pipe 9, a first reservoir connection flow path 63a communicating with the internal space of the first reservoir cylinder 10, and a second reservoir connection flow path 64a communicating with the internal space of the second reservoir cylinder 20. In addition, the valve body 61 has a first reservoir flow path 66 connecting between the supply switching valve core 62 and the first reservoir valve core 63, a second reservoir flow path 67 connecting between the supply switching valve core 62 and the second reservoir valve core 64, an intermediate flow path 68 connecting between the first reservoir valve core 63, the second reservoir valve core 64 and the discharge switching valve core 65, and a discharge connection flow path 69 communicating from the discharge switching valve core 65 to the supply connection flow path 53 of the injection switching valve 50. In addition, the valve body 61 has a discharge flow path 65a communicating with the flow path of the discharge portion 70.

[0066] Each valve core rotates independently of each other through the valve core driving unit, thereby adjusting the posture in the valve body 61 respectively, so that the flow path of each valve core is connected to an arbitrary flow path, and the flow path of each valve core is cut off from the connection with other flow paths. The posture of each valve core when supplying molten resin will be described in detail in the following operation method.

[0067] The discharge unit 70 includes a discharge pipe 71 connected to the reservoir switching valve 60 and a disposal unit 72 outside the injection device 3 connected via the discharge pipe 71. The molten resin is discharged to the disposal unit 72 via the discharge pipe 71 according to the switching of the reservoir switching valve 60.

[0068] The functions of the control unit 80 can be implemented by any hardware, software or a combination thereof. For example, the control unit 80 can apply a computer having a processor, memory, input / output interface and communication interface (not shown). The processor is a combination of one or more of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array) and a circuit composed of multiple discrete semiconductors, and executes and processes programs stored in the memory. The memory includes a main storage device composed of a semiconductor memory and an auxiliary storage device composed of a disk or a semiconductor memory (flash memory).

[0069] The control unit 80 controls the operation of each structure of the injection device 3 (the first injection component driving unit 15, the second injection component driving unit 25, the third injection component driving unit 35, the injection switching valve 50, the reservoir switching valve 60, etc.) according to various instructions of the controller 4 that controls the entire injection molding machine system S. In addition, the injection molding machine system S may also be a structure in which the controller 4 also serves as the control unit 80 of the injection device 3 (that is, directly controls the injection device 3).

[0070] The control unit 80 reads and executes the program in the memory through the processor, thereby constructing the first injection component control unit 81, the second injection component control unit 82, the third injection component control unit 83 and the flow path switching processing unit 84 inside. The first injection component control unit 81 controls the action of the first reservoir plunger 12. The second injection component control unit 82 controls the action of the second reservoir plunger 22. The third injection component control unit 83 controls the action of the injection plunger 32. The flow path switching processing unit 84 controls the states of the injection switching valve 50 and the reservoir switching valve 60 to switch the flow direction of the molten resin.

[0071] <Operation of the injection device 3>

[0072] Next, use Figure 3 The operation of the injection device 3 of the injection molding machine 1 will be described. Figure 3 3 is a flowchart showing the operation of the injection device 3 when viewed from the injection cylinder 30. The injection device 3 performs the following operations in sequence under the control of the control unit 80: Figure 3 The metering step (step S110), the filling step (step S120) and the pressure holding step (step S130) are shown, and these steps are repeated.

[0073] In the metering process, the injection device 3 accumulates a specified amount of molten resin at the front end side of the internal space of the injection cylinder 30 (in front of the injection plunger 32). In the filling process, the injection device 3 fills the molten resin accumulated in the metering process into the cavity space of the mold device 2a through the injection nozzle 40 by advancing the injection plunger 32 of the injection cylinder 30. In the pressure holding process, the injection device 3 maintains the pressure of the molten resin in front of the injection plunger 32 (holding pressure) at a set pressure while extruding the molten resin remaining in the injection cylinder 30 toward the mold device 2a for injection. In addition, the injection molding machine 1 starts a cooling process after the pressure holding process to solidify the molten resin in the cavity space of the mold device 2a. In order to shorten the molding cycle time, the injection molding machine 1 can perform a metering process in the cooling process.

[0074] Furthermore, the injection device 3 selects the first reservoir cylinder 10 and the second reservoir cylinder 20 in the above-mentioned metering process and injection process (filling process, pressure holding process) to control metering and injection on the reservoir side. Figure 4 (A)~ Figure 5 (B) describes the specific actions in each process. Figure 4 (A) is a cross-sectional view showing the operation of the injection cylinder 30 in the metering process. Figure 4 (B) is a diagram showing the operation of the injection cylinder 30 during the injection process. Figure 5 (A) is a cross-sectional view showing the operation of another reservoir cylinder in the metering process of the injection cylinder 30 . Figure 5 (B) is a diagram showing the discharge operation of the molten resin.

[0075] In the metering process (step S110), the control unit 80 selects a cylinder that stores (meters) a predetermined amount of molten resin, out of the first and second reservoir cylinders 10 and 20 on the reservoir side. Figure 4 (A) shows an example in which the molten resin in the second reservoir cylinder 20 is moved to the injection cylinder 30 because the molten resin is stored in the second reservoir cylinder 20. The flow path switching processing unit 84 of the control unit 80 controls the valve core driving unit of the injection switching valve 50 and the valve core driving unit of the reservoir switching valve 60 according to the selection, so that each valve core becomes Figure 4 The posture shown in (A).

[0076] Specifically, the valve core 52 of the injection switching valve 50 is adjusted by the valve core driving unit to a direction (first state) that connects the supply connection flow path 53 with the injection cylinder connection flow path 54. On the other hand, in the reservoir switching valve 60, the second reservoir valve core 64 is adjusted to a direction that connects the second reservoir connection flow path 64a with the intermediate flow path 68 and cuts off the connection with the second reservoir flow path 67. In addition, the discharge switching valve core 65 is adjusted to a direction that connects the intermediate flow path 68 with the discharge connection flow path 69 and cuts off the connection with the discharge flow path 65a. Thus, the second reservoir cylinder 20 and the injection cylinder 30 are connected via the second reservoir connection flow path 64a, the second reservoir valve core 64, the intermediate flow path 68, the discharge switching valve core 65, the discharge connection flow path 69, the supply connection flow path 53, the valve core 52 and the injection cylinder connection flow path 54.

[0077] After adjusting the posture of each valve core based on the flow path switching processing unit 84, the control unit 80 drives the advance / retract motor 26 through the second injection unit control unit 82 to advance the second reservoir plunger 22 of the second reservoir cylinder 20. At this time, the second injection unit control unit 82 calculates the position or movement speed of the second reservoir plunger 22 based on the detection value of the encoder 17, and controls the movement speed of the second reservoir plunger 22. The second reservoir plunger 22 squeezes out the molten resin accumulated in front of the second reservoir plunger 22 in the internal space of the second reservoir cylinder 20 from the front end of the second reservoir cylinder 20. The molten resin of the second reservoir cylinder 20 moves through the second reservoir connecting flow path 64a, the second reservoir valve core 64, the intermediate flow path 68, the discharge switching valve core 65, and the discharge connecting flow path 69 in the reservoir switching valve 60. At this time, the second reservoir valve element 64 blocks the second reservoir flow path 67 to prevent the molten resin from flowing back to the supply pipe 9 via the second reservoir flow path 67. Then, the molten resin extruded from the reservoir switching valve 60 flows into the internal space of the injection cylinder 30 via the supply connecting flow path 53 of the injection switching valve 50, the valve element 52, and the injection cylinder connecting flow path 54.

[0078] When the molten resin flows into the injection cylinder 30, the injection plunger 32 of the injection cylinder 30 is pushed by the molten resin and retreats in the injection cylinder 30. In addition, the control unit 80 may drive the advance and retreat motor 36 through the third injection unit control unit 83 to actively retreat the injection plunger 32 so as to be linked with the inflow of the molten resin. In this way, the pressure of the molten resin supplied to the injection cylinder 30 can be reduced, and the load on the second reservoir plunger 22 can be reduced.

[0079] Furthermore, when the molten resin is moved from the second reservoir cylinder 20 to the injection cylinder 30, the control unit 80 fills the first reservoir cylinder 10 with the molten resin continuously supplied from the supply pipe 9. Therefore, in the adjustment of each valve core of the reservoir switching valve 60, the flow path switching processing unit 84 also adjusts the supply switching valve core 62 and the first reservoir valve core 63 at the same time. Specifically, the supply switching valve core 62 is adjusted to a direction in which the supply flow path 62a is connected to the first reservoir flow path 66 and the connection with the second reservoir flow path 67 is cut off. The first reservoir valve core 63 is adjusted to a direction in which the first reservoir connecting flow path 63a is connected to the first reservoir flow path 66 and the connection with the intermediate flow path 68 is cut off.

[0080] As a result, the supply flow path 62a, the supply switching valve core 62, the first reservoir flow path 66, the first reservoir valve core 63, and the first reservoir connection flow path 63a are connected to each other, and the molten resin of the supply pipe 9 flows into the first reservoir cylinder 10. In the first reservoir cylinder 10, the first reservoir plunger 12 gradually retreats with the inflow of the molten resin, thereby storing the molten resin. In addition, at this time, the control unit 80 can drive the advance and retreat motor 16 through the first injection unit control unit 81 to actively retreat the first reservoir plunger 12 so as to be linked with the inflow of the molten resin.

[0081] After the above-mentioned metering process, the control unit 80 starts the filling process (step S120). The flow path conversion processing unit 84 of the control unit 80 controls the valve core driving unit of the injection switching valve 50 and the valve core driving unit of the reservoir switching valve 60 to make each valve core Figure 4 The posture shown in (B).

[0082] Specifically, the valve core 52 of the injection switching valve 50 is adjusted by the valve core driving unit to connect the injection cylinder connecting flow path 54 with the nozzle connecting flow path 55 and cut off the direction of the supply connecting flow path 53 (second state). In addition, the third injection component control unit 83 of the control unit 80 drives the advance and retreat motor 36 to advance the injection plunger 32 to a predetermined position. At this time, the third injection component control unit 83 calculates the position or movement speed of the injection plunger 32 based on the detection value of the encoder 37, and controls the movement speed of the injection plunger 32. The injection plunger 32 discharges the molten resin accumulated in front of the injection plunger 32 in the internal space of the injection cylinder 30 from the front end of the injection cylinder 30. The molten resin of the injection cylinder 30 moves to the injection nozzle 40 via the injection switching valve 50, flows in the flow path of the injection nozzle 40, and fills the cavity space of the mold device 2a.

[0083] Furthermore, the injection device 3 performs a process (reservoir storage process) of supplying molten resin to the cylinder (second reservoir cylinder 20) which has supplied molten resin to the injection cylinder 30 in the previous metering process in the injection process (filling process) in which the injection cylinder 30 injects molten resin into the mold device 2a. However, the supply of molten resin to the second reservoir cylinder 20 may be performed after the supply of molten resin to the first reservoir cylinder 10 in the above-mentioned metering process is completed.

[0084] When the molten resin is supplied to the second reservoir cylinder 20, the flow path switching processing unit 84 of the control unit 80 adjusts the posture of each valve element of the reservoir switching valve 60. For example, the supply switching valve element 62 is adjusted to a posture that allows the supply flow path 62a to communicate with the second reservoir flow path 67 and cuts off the first reservoir flow path 66. The first reservoir valve element 63 is adjusted to a posture that cuts off the first reservoir connecting flow path 63a. The second reservoir valve element 64 is adjusted to a posture that allows the second reservoir connecting flow path 64a to communicate with the second reservoir flow path 67 and cuts off the intermediate flow path 68.

[0085] As a result, the supply flow path 62a, the supply switching valve core 62, the second reservoir flow path 67, the second reservoir valve core 64, and the second reservoir connection flow path 64a are connected to each other, and the molten resin of the supply pipe 9 flows into the second reservoir cylinder 20. In the second reservoir cylinder 20, as the molten resin flows in, the second reservoir plunger 22 gradually retreats to store the molten resin. In addition, at this time, the control unit 80 can drive the advance and retreat motor 26 through the second injection unit control unit 82 to actively retreat the second reservoir plunger 22 so as to be linked with the inflow of the molten resin.

[0086] After the above-mentioned filling process, the control unit 80 starts the pressure holding process (step S130). At this time, the third injection component control unit 83 of the control unit 80 controls the rotation of the advance and retreat motor 36 according to the detection value of the pressure detection unit 38, so that the pressure (holding pressure) of the molten resin extruded by the injection plunger 32 is maintained at the set pressure, and the injection plunger 32 is advanced. Through the advancement of the injection plunger 32, the injection plunger 32 can extrude the molten resin remaining in the internal space of the injection cylinder 30 toward the mold device 2a. In addition, during the pressure holding process, the control unit 80 can also continue the above-mentioned reservoir storage process.

[0087] When the pressure holding process is completed, the injection molding machine 1 returns to step S110 again and starts the metering process of the injection cylinder 30. As described above, the control unit 80 selects the cylinder that stores (meters) a predetermined amount of molten resin from among the first reservoir cylinder 10 and the second reservoir cylinder 20 on the reservoir side. Figure 4 (A) and Figure 4 As shown in (B), since the molten resin is stored in the first storage cylinder 10, the control unit 80 selects to move the molten resin in the first storage cylinder 10 to the injection cylinder 30 and makes each valve core Figure 5 The posture shown in (A).

[0088] Specifically, the valve core 52 of the injection switching valve 50 is adjusted by the valve core driving unit to a direction that allows the supply connection flow path 53 to communicate with the injection cylinder connection flow path 54 (first mode). In addition, in the reservoir switching valve 60, the first reservoir valve core 63 is adjusted to a direction that allows the first reservoir connection flow path 63a to communicate with the intermediate flow path 68 and cuts off the connection with the first reservoir flow path 66. In addition, the discharge switching valve core 65 is adjusted to a direction that allows the intermediate flow path 68 to communicate with the discharge connection flow path 69 and cuts off the connection with the discharge flow path 65a. As a result, the first reservoir cylinder body 10 and the injection cylinder 30 are connected via the first reservoir connection flow path 63a, the first reservoir valve core 63, the intermediate flow path 68, the discharge switching valve core 65, the discharge connection flow path 69, the supply connection flow path 53, the valve core 52 and the injection cylinder connection flow path 54.

[0089] After adjusting the posture of each valve core based on the flow path switching processing unit 84, the control unit 80 drives the advance / retract motor 16 through the first injection component control unit 81 to advance the first reservoir plunger 12 of the first reservoir cylinder 10. At this time, the first injection component control unit 81 calculates the position or movement speed of the first reservoir plunger 12 based on the detection value of the encoder 17, and controls the movement speed of the first reservoir plunger 12. The first reservoir plunger 12 discharges the molten resin accumulated in front of the first reservoir plunger 12 in the internal space of the first reservoir cylinder 10 from the front end of the first reservoir cylinder 10. The molten resin of the first reservoir cylinder 10 moves through the first reservoir connecting flow path 63a, the first reservoir valve core 63, the intermediate flow path 68, the discharge switching valve core 65, and the discharge connecting flow path 69 in the reservoir switching valve 60. At this time, the first reservoir valve element 63 prevents the molten resin from flowing back to the first reservoir flow path 66 by shutting off the first reservoir flow path 66. Then, the molten resin extruded from the reservoir switching valve 60 flows into the internal space of the injection cylinder 30 via the supply connection flow path 53 of the injection switching valve 50, the valve element 52, and the injection cylinder connection flow path 54.

[0090] Then, when the molten resin is stored in the injection cylinder 30, the injection plunger 32 of the injection cylinder 30 is pushed by the molten resin and retreats in the injection cylinder 30. In addition, at this time, the control unit 80 may also drive the advance and retreat motor 36 through the third injection unit control unit 83 to actively retreat the injection plunger 32 so as to be linked with the inflow of the molten resin.

[0091] Furthermore, when the molten resin is moved from the first reservoir cylinder 10 to the injection cylinder 30, the control unit 80 also controls the molten resin to move from the first reservoir cylinder 10 to the injection cylinder 30. Figure 4After the injection process (pressure holding process) of (B), the molten resin continuously supplied from the supply pipe 9 is continuously filled into the second reservoir cylinder 20. Therefore, the supply switching valve core 62 makes the supply flow path 62a communicate with the second reservoir flow path 67, and the second reservoir valve core 64 makes the second reservoir connecting flow path 64a communicate with the second reservoir flow path 67.

[0092] Thus, the supply flow path 62a, the supply switching valve core 62, the second reservoir flow path 67, the second reservoir valve core 64, and the second reservoir connecting flow path 64a are connected to each other, and the molten resin of the supply pipe 9 flows into the second reservoir cylinder 20. In the second reservoir cylinder 20, as the molten resin flows in, the second reservoir plunger 22 gradually retreats, thereby storing the molten resin.

[0093] Figure 6 This is a first flow chart showing control of the first accumulator cylinder 10 and the second accumulator cylinder 20 and control of the injection cylinder 30 . Figure 7 1 is a second flow chart showing the control of the first accumulator cylinder 10 and the second accumulator cylinder 20 and the control of the injection cylinder 30. If the control of the conversion of the molten resin in the above injection device 3 is summarized, it becomes as follows: Figure 6 and Figure 7 As shown in the flowchart.

[0094] In the metering process, the control unit 80 first selects a storage cylinder storing molten resin (step S111). For example, when molten resin is stored in the first storage cylinder 10, the process proceeds to step S112, and when molten resin is stored in the second storage cylinder 20, the process proceeds to step S114.

[0095] In step S112, the control unit 80 advances the first reservoir plunger 12 to move the molten resin from the first reservoir cylinder 10 to the injection cylinder 30, and on the other hand, supplies the molten resin from the supply pipe 9 to the second reservoir cylinder 20. Then, the control unit 80 monitors the retreat position of the injection plunger 32 and determines whether the filling of the molten resin into the injection cylinder 30 has been completed (step S113). When the filling of the molten resin has not been completed (step S113: No), the control unit 80 returns to step S112 and repeats the same processing. On the other hand, when the filling of the molten resin has been completed (step S113: Yes), the control unit 80 ends the metering process from the first reservoir cylinder 10 to the injection cylinder 30 and transitions to the injection process (filling process, pressure holding process).

[0096] Furthermore, in step S114, the control unit 80 advances the second reservoir plunger 22 to move the molten resin from the second reservoir cylinder 20 to the injection cylinder 30, and on the other hand, supplies the molten resin from the supply pipe 9 to the first reservoir cylinder 10. Then, the control unit 80 monitors the retreat position of the injection plunger 32 and determines whether the filling of the molten resin into the injection cylinder 30 has been completed (step S115). When the filling of the molten resin has not been completed (step S115: No), the control unit 80 returns to step S114 and repeats the same processing. On the other hand, when the filling of the molten resin has been completed (step S115: Yes), the control unit 80 ends the metering process from the second reservoir cylinder 20 to the injection cylinder 30 and transitions to the injection process.

[0097] In the injection process, the control unit 80 advances the injection plunger 32 to inject the molten resin filled (measured) in the injection cylinder 30 into the mold device 2a (step S121). At this time, the control unit 80 adjusts the pressure of the molten resin injected into the mold device 2a by performing the filling process and the pressure holding process.

[0098] Furthermore, the control unit 80 monitors the forward position of the injection plunger 32 during the injection process to determine whether the injection of the molten resin into the mold device 2a has been completed (step S122). If the injection of the molten resin has not been completed (step S122: No), the process returns to step S121 and the same process is repeated. On the other hand, if the injection of the molten resin has been completed (step S122: Yes), the injection process based on the injection cylinder 30 is completed. The metering process and the injection process of the injection cylinder 30 are set to a period earlier than the period of supplying the molten resin to one storage cylinder. Therefore, if the injection process of the injection cylinder 30 is completed, the control unit 80 temporarily waits until the storage process of the storage is completed.

[0099] Then, the control unit 80 supplies the molten resin from the supply pipe 9 to the storage side in parallel with the injection process of the injection cylinder 30. Specifically, the control unit 80 selects the storage cylinder body to which the molten resin is supplied (step S123). For example, the control unit 80 continues to supply the molten resin to the storage cylinder body to which the molten resin is supplied in the metering process during the injection process. In addition, when the supply of the storage cylinder body to which the molten resin is supplied in the metering process has been completed, the control unit 80 switches to another storage cylinder body and continues to supply the molten resin. In this way, it is possible to avoid stopping the supply of the molten resin from the supply pipe 9.

[0100] For example, the control unit 80 supplies molten resin from the supply pipe 9 to the first reservoir cylinder 10 according to the determination of step S123 (step S124). Then, the control unit 80 monitors the retreat position of the first reservoir plunger 12 and determines whether the filling of the molten resin into the first reservoir cylinder 10 has been completed (step S125). When the filling of the molten resin has not been completed (step S125: No), the control unit 80 returns to step S123 and repeatedly performs the same processing. On the other hand, when the filling of the molten resin has been completed (step S125: Yes), the control unit 80 ends the reservoir storage process for the first reservoir cylinder 10.

[0101] And, for example, the control unit 80 supplies molten resin from the supply pipe 9 to the second reservoir cylinder 20 according to the determination of step S123 (step S126). Then, the control unit 80 monitors the retreat position of the second reservoir plunger 22 and determines whether the filling of the molten resin into the second reservoir cylinder 20 has been completed (step S127). When the filling of the molten resin has not been completed (step S127: No), the control unit 80 returns to step S123 and repeats the same processing. On the other hand, when the filling of the molten resin has been completed (step S127: Yes), the control unit 80 ends the reservoir storage process for the second reservoir cylinder 20.

[0102] The control unit 80 can repeatedly mold molded products using the injection molding machine 1 by repeatedly performing the above processing flow. During injection molding, the molten resin continuously fed from the supply pipe 9 is alternately stored in the first storage cylinder 10 and the second storage cylinder 20 as described above, and extruded into the injection cylinder 30. While the molten resin is extruded from one storage cylinder, the molten resin is supplied to the other storage cylinder. Thus, the injection device 3 can smoothly switch without cutting off the molten resin continuously supplied from the supply pipe 9, and can prevent blockage and backflow of the molten resin. Moreover, even when the injection plunger 32 injects the molten resin, the injection device 3 can stably fill the molten resin into the storage cylinder by supplying the molten resin to any one of the first storage cylinder 10 and the second storage cylinder 20.

[0103] In particular, by connecting the reservoir switching valve 60 to the front end of the first reservoir cylinder 10 and the front end of the second reservoir cylinder 20, the molten resin can be supplied from the front end of the first reservoir cylinder 10 and the front end of the second reservoir cylinder 20. As a result, the molten resin can be filled and extruded without deteriorating the molten resin due to the rotation of the screw. In addition, by switching the first reservoir cylinder 10 and the second reservoir cylinder 20 through the reservoir switching valve 60, the molten resin continuously supplied through the supply pipe 9 can be stored without interruption.

[0104] Furthermore, the injection device 3 includes the injection switching valve 50 connected to the front end of the injection cylinder 30 and connected to the reservoir switching valve 60, so that the metering process and the injection process in the injection cylinder 30 can be stably performed. Furthermore, the reservoir switching valve 60 includes the discharge portion 70 that discharges the molten resin when the injection molding machine 1 is stopped. Therefore, when it is necessary to stop the supply of the molten resin due to an error or the like, the molten resin can be discharged from the injection switching valve 50, and the clogging and backflow of the supply pipe 9 can be prevented.

[0105] In addition, the injection molding machine 1 may stop injecting molten resin into the mold device 2a due to an error in the device. In this case, the injection device 3 controls the molten resin supplied from the molten resin supply device 6 to the reservoir switching valve 60 to be directed to the discharge portion 70 and discarded. For example, the flow path switching processing unit 84 of the control unit 80 controls the valve core driving unit of the injection switching valve 50 and the valve core driving unit of the reservoir switching valve 60 to make each valve core Figure 5 The posture shown in (B).

[0106] Specifically, the supply switching valve core 62 is adjusted to a direction that allows the supply flow path 62a, the first reservoir flow path 66, and the second reservoir flow path 67 to communicate with each other. The first reservoir valve core 63 is adjusted to a direction that allows the first reservoir flow path 66 to communicate with the intermediate flow path 68. The second reservoir valve core 64 is adjusted to a direction that allows the second reservoir flow path 67 to communicate with the intermediate flow path 68. Moreover, the discharge switching valve core 65 is adjusted to a direction that allows the intermediate flow path 68 to communicate with the discharge flow path 65a and cuts off the communication with the discharge connection flow path 69. Thus, the supply piping 9 and the discharge portion 70 are connected via the supply flow path 62a, the supply switching valve core 62, the first reservoir flow path 66, the first reservoir valve core 63 (or the second reservoir flow path 67, the second reservoir valve core 64), the intermediate flow path 68, the discharge switching valve core 65, and the discharge flow path 65a.

[0107] As a result, the molten resin supplied from the supply pipe 9 is discharged to the discharge portion 70 without passing through the inside of the reservoir switching valve 60 and filling the first reservoir cylinder 10 and the second reservoir cylinder 20. The molten resin is discharged to the waste portion 72 via the discharge pipe 71 of the discharge portion 70. Therefore, even when the injection molding is stopped, the injection molding machine 1 can well prevent the clogging and backflow of the molten resin.

[0108] In addition, the injection molding machine 1 is not limited to the above-mentioned embodiment, and various modifications can be adopted. For example, the above-mentioned injection device 3 uses a plunger that moves forward and backward as the first reservoir plunger 12 of the first reservoir cylinder 10 and the second reservoir plunger 22 of the second reservoir cylinder 20. However, the first reservoir plunger 12 and the second reservoir plunger 22 are not limited to this, and a screw that rotates around an axis inside the first reservoir cylinder 10 and the second reservoir cylinder 20 to move the molten resin to the front end can also be adopted. At this time, the supply pipe 9 can adopt a structure that is connected to the base end side of the first reservoir cylinder 10 and the second reservoir cylinder 20 and selects the first reservoir cylinder 10 and the second reservoir cylinder 20 to supply the molten resin. In addition, in this example, the flow path is converted in a T shape at the intersection of each flow path, but it is also possible to directly penetrate each intersection and set a flow path throttle valve in the middle of each flow path to make it perform the same action.

[0109] The injection molding machine 1 involved in the embodiment disclosed this time is illustrative in all aspects and is not restrictive. The embodiment can be deformed and improved in various ways without departing from the attached technical solution and its main purpose. Regarding the matters recorded in the above-mentioned multiple embodiments, other structures can also be adopted within the scope of non-contradiction, and they can be combined within the scope of non-contradiction.

Claims

1. An injection molding machine, comprising: The first reservoir cylinder and the second reservoir cylinder are supplied with molten resin; a first injection component disposed inside the first reservoir cylinder and extruding the molten resin of the first reservoir cylinder; a second injection component disposed inside the second reservoir cylinder and extruding the molten resin of the second reservoir cylinder; as well as an injection cylinder to which the molten resin of the first reservoir cylinder and the molten resin of the second reservoir cylinder are supplied, When the molten resin is supplied from the first reservoir cylinder to the injection cylinder, the molten resin is supplied to the interior of the second reservoir cylinder. On the other hand, when the molten resin is supplied from the second reservoir cylinder to the injection cylinder, the molten resin is supplied to the interior of the first reservoir cylinder.

2. The injection molding machine according to claim 1, wherein: A reservoir switching portion is provided, the reservoir switching portion being connected to the front end of the first reservoir cylinder and the front end of the second reservoir cylinder and supplying the molten resin to the first reservoir cylinder and the second reservoir cylinder.

3. The injection molding machine according to claim 2, wherein: The reservoir switching section switches the first reservoir cylinder and the second reservoir cylinder so that the molten resin continuously supplied through a supply pipe flows into either the first reservoir cylinder or the second reservoir cylinder.

4. The injection molding machine according to claim 3, wherein: An injection conversion unit is provided, the injection conversion unit is connected to the front end of the injection cylinder and is connected to the reservoir conversion unit, The molten resin extruded from the first reservoir cylinder or the second reservoir cylinder is supplied from the reservoir switching portion to the injection cylinder via the injection switching portion.

5. The injection molding machine according to claim 4, wherein: The injection switching portion blocks communication with the reservoir switching portion during an injection step to allow injection of the molten resin supplied to the injection cylinder.

6. The injection molding machine according to claim 2, wherein: The reservoir switching unit includes a discharge unit configured to discharge the molten resin when the injection molding machine stops.

7. The injection molding machine according to any one of claims 1 to 6, wherein: A third injection component is provided, the third injection component is provided inside the injection cylinder, and injects the molten resin in the injection cylinder, When the molten resin is injected from the injection cylinder, the third injection member supplies the molten resin to any one of the first reservoir cylinder and the second reservoir cylinder.

8. An injection molding machine system comprising: an injection molding machine for injecting molten resin into a mold device; and a molten resin supply device for supplying the molten resin to the injection molding machine, wherein: The injection molding machine comprises: The first reservoir cylinder and the second reservoir cylinder are supplied with the molten resin; a first injection component disposed inside the first reservoir cylinder and extruding the molten resin of the first reservoir cylinder; a second injection component disposed inside the second reservoir cylinder and extruding the molten resin of the second reservoir cylinder; and an injection cylinder to which the molten resin of the first reservoir cylinder and the molten resin of the second reservoir cylinder are supplied, When the molten resin is supplied from the first reservoir cylinder to the injection cylinder, the molten resin is supplied to the interior of the second reservoir cylinder. On the other hand, when the molten resin is supplied from the second reservoir cylinder to the injection cylinder, the molten resin is supplied to the interior of the first reservoir cylinder.

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