Injection molding machine

Abstract

To provide an injection molding machine capable of improving the calculation precision of an amount of a molding material filled in a barrel.SOLUTION: An injection molding machine 1 includes a barrel 2, a nozzle 3, a plunger 6, a rod 8 having a torpedo 16, a head 9, a heater 4 for heating a molding material supplied to the inside of the barrel, and a controller 12 for calculating a fill factor of a filler resin, wherein the filler resin is a plasticized resin raw material filled between the torpedo 16 and the nozzle 3 inside the barrel 2, based on a position of the rod 8 in an axial direction A, a load applied from the filler resin to the rod 8, and a temperature of the heater 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an injection molding machine. [Background technology]

[0002] For example, some plastic parts for automobiles and the like are molded using an injection molding machine that injects molding material such as raw plastic into a mold. In an injection molding machine, there is a possibility that an excess or shortage of material may occur due to the balance between the amount of resin injected and the amount of resin supplied.

[0003] For example, Patent Document 1 discloses detecting the position of a plunger in a barrel to grasp the amount of resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 60-87030 Summary of the Invention [Problem to be solved by the invention]

[0005] However, for example, when switching the type of resin raw material used, the type and size of the resin raw material will change. Since the resin raw material before plasticization is in the form of pellets, for example, the gaps and melting properties will differ depending on the resin raw material. Therefore, even if the amount of resin is the same, the position of the plunger may differ depending on the resin raw material, which may cause an excess or shortage of material.

[0006] In view of the above problems, an object of the present invention is to provide an injection molding machine that can improve the accuracy of calculating the amount of molding material filled in a barrel. [Means for solving the problem]

[0007] In order to solve the above problem, the injection molding machine of the present invention comprises a hollow barrel extending in one direction, a nozzle provided at one end side of the barrel in the one direction and for injecting molding material plasticized inside the barrel, an extrusion section for extruding the molding material supplied inside the barrel toward the nozzle side, a rod extending in the one direction of the barrel through the extrusion section and having a torpedo at an end side closer to the nozzle than the extrusion section, a head provided at an end side of the rod on the nozzle side, a heating section for heating the molding material supplied inside the barrel, and a control device for calculating information regarding the filling amount of the filling material, based on the position of the rod in the one direction, the load applied to the rod from the filling material, and the temperature of the heating section, using the plasticized molding material filled between the torpedo and the nozzle inside the barrel as a filling material.

[0008] The control device also calculates a filling rate of the filling material as information regarding the filling amount of the filling material.

[0009] The load applied to the rod is a load that the rod receives from the filling material when the molding material is extruded as the filling material between the torpedo and the nozzle by the extrusion section.

[0010] In addition, the heating section has a first heating section provided for the barrel, a second heating section provided for the nozzle, and a third heating section provided for the rod, and the control device uses the temperatures of the first heating section, the second heating section, and the third heating section as the temperatures of the heating section, and calculates information regarding the filling amount of the filling material.

[0011] The control device also sets the amount of the molding material before plasticization to be supplied to the barrel based on information regarding the filling amount of the filling material.

[0012] the nozzle is disposed on one end of the barrel and configured to inject molding material plasticized within the barrel; an extrusion section is disposed on one end of the barrel and configured to extrude the molding material supplied inside the barrel toward the nozzle; a rod is disposed on the one end of the rod and extends through the extrusion section in the one direction and has a torpedo at an end closer to the nozzle than the extrusion section; a head is disposed on the end of the rod on the nozzle side; a heating section is disposed on the molding material supplied inside the barrel; a temperature sensor is disposed on the heating section; Effect of the Invention

[0013] According to the injection molding machine of the present invention, it is possible to improve the accuracy of calculating the amount of molding material filled in the barrel. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating a schematic configuration of an injection molding machine according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing an example of various functions in the control device of FIG. 1. [Diagram 3] FIG. 2 is a diagram showing an example of a first step of injection molding using the injection molding machine of FIG. [Figure 4] 3 is a diagram showing an example of a second step of injection molding using the injection molding machine of FIG. 1. FIG. [Diagram 5] 3 is a diagram showing an example of a third step of injection molding using the injection molding machine of FIG. 1. FIG. [Figure 6] 1. FIG. 4 is a diagram showing an example of a fourth step of injection molding using the injection molding machine of FIG. [Figure 7] 2 is a flowchart showing an example of a flow of injection molding using the injection molding machine of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same reference numerals are used to designate the same components in each drawing, and duplicated description will be omitted as appropriate.

[0016] === Implementation form === <Overall composition> Fig. 1 is a diagram showing a schematic configuration of an injection molding machine 1 according to a first embodiment. In Fig. 1, a rod 8, a head 9, and a non-return ring 10, which will be described later, are shown as cross sections only on one side (the side on which a material supply unit 11 is provided) with respect to a central axis X of a barrel 2, and the other side with respect to the central axis X is shown as a side surface.

[0017] 1, an injection molding machine 1 plasticizes a molding material, such as a resin raw material, inside the machine and injects the plasticized resin raw material to the outside of a mold or the like. The injection molding machine 1 mainly includes a barrel 2, a nozzle 3, a heater 4, a plunger 6, a rod 8, a head 9, a check ring 10, a material supply unit 11, and a control device 12. For example, when a fluororesin is used as the resin raw material, each member that comes into contact with the resin raw material is made of an Invar material or the like that is resistant to corrosion by the fluororesin.

[0018] The barrel 2 has a cylindrical shape. The barrel 2 extends in one direction and is hollow. The axial direction of the barrel 2 along that direction is referred to as the "axial direction A". A nozzle 3 is provided at one end of the barrel 2 in the axial direction A. The end of the barrel 2 where the nozzle 3 in the axial direction A is provided (the injection side of the resin raw material) is referred to as the "downstream side", and the other end of the barrel 2 opposite to the end where the nozzle 3 in the axial direction A is provided (the supply side of the resin raw material) is referred to as the "upstream side".

[0019] The barrel 2 has, for example, a large diameter section 20 to which the resin raw material is supplied, and a small diameter section 22 located downstream of the large diameter section 20 and having an outer diameter smaller than that of the large diameter section 20 .

[0020] The nozzle 3 is provided at one end of the barrel 2 in the axial direction A. Specifically, it is provided at the end of the barrel 2 on the downstream side in the axial direction A. The nozzle 3 has a nozzle hole 3a, and injects a plasticized resin raw material from the nozzle hole 3a toward the outside of a mold or the like. In FIG. 1, the nozzle 3 is shown as an open nozzle in which the nozzle hole 3a is open, but the nozzle 3 may be a shut-off nozzle having a valve capable of opening and closing the nozzle hole 3a.

[0021] The heater 4 is provided on the outer peripheral surface 2a of the barrel 2. The heater 4 is a heating section that heats the barrel 2 from the outside and heats the resin raw material inside the barrel 2 via the barrel 2. The heater 4 has a first heater section 4a provided for the large diameter section 20 of the barrel 2, a second heater section 4b provided for the small diameter section 22 of the barrel 2, and a nozzle heater section 4c provided for the nozzle 3. The heater 4 also has an internal heater 18 that heats the resin raw material from inside the barrel 2, as described below.

[0022] The inner peripheral surface 2b of the barrel 2 has a tapered surface 20b inclined with respect to the axial direction A and a parallel surface 22b approximately parallel to the axial direction A in a range facing the portion of the outer peripheral surface 2a of the barrel 2 where the heater 4 is provided. The tapered surface 20b is formed so that the inner diameter becomes narrower from the upstream side to the downstream side. The tapered surface 20b is formed in a range of the inner peripheral surface 2b of the barrel 2 facing the portion of the outer peripheral surface 2a of the barrel 2 where the first heater section 4a is provided, that is, at the position of the large diameter section 20. The range in which the tapered surface 20b is formed is a position on the inner peripheral surface 2b of the barrel 2 that is downstream of the movable range of the plunger 6 and upstream of the movable range of the torpedo 16 (between the movable range of the plunger 6 and the movable range of the torpedo 16).

[0023] The parallel surface 22b is located downstream of the tapered surface 20b in the axial direction A, and is formed to have approximately the same inner diameter along the axial direction A. The parallel surface 22b is formed in a range of the inner circumferential surface 2b of the barrel 2 that faces a portion of the outer circumferential surface 2a of the barrel 2 where the second heater portion 4b is provided, that is, at the position of the small diameter portion 22. For example, the length of the parallel surface 22b in the axial direction A is longer than the length of the tapered surface 20b in the axial direction A.

[0024] The plunger 6 is an extrusion part that extrudes the resin raw material supplied inside the barrel 2 to the downstream side inside the barrel 2. The plunger 6 is provided so as to fit into an opening 2c formed at the upstream end of the barrel 2. A through hole 6c through which the rod 8 passes is formed in the center of the plunger 6. That is, the plunger 6 is hollow. The plunger 6 is a linear-acting extrusion part that moves along the axial direction A. The plunger 6 is connected to an actuator (not shown) via a predetermined fixing member 7a, for example, and moves in the axial direction A by the actuator without rotating. The plunger 6 may move (link) with the movement of the rod 8 by being fixed to the rod 8.

[0025] The rod 8 is provided inside the barrel 2 and extends in the axial direction A. The rod 8 is movable in the axial direction A. The rod 8 is disposed inside the barrel 2, for example, in a state in which it passes through the through hole 6c of the plunger 6 (inserted into the plunger 6), and extends in the axial direction A of the barrel 2. The rod 8 is connected to an actuator (not shown) via a predetermined fixing member 7b, for example, and is moved in the axial direction A by the actuator.

[0026] The rod 8 is provided with a torpedo 16. The torpedo 16 is formed on the downstream side of the rod 8, between the head 9 and the plunger 6. The torpedo 16 is formed integrally with the rod 8. Note that the torpedo 16 may be formed separately from the rod 8 and fixed to the rod 8. The torpedo 16 moves integrally with the rod 8 inside the barrel 2 along the axial direction A via the movement of the rod 8.

[0027] Torpedo 16 has a tapered portion that narrows from the downstream side to the upstream side. That is, torpedo 16 has tapered surface 16a, which is a tapered outer circumferential surface formed so that the outer diameter narrows from the downstream side to the upstream side. In addition, torpedo 16 has an outer diameter at downstream end 16b that has a gear shape, and end 16b has a large number of fins formed as protrusions.

[0028] The rod 8 also has an internal heater 18 as the heater 4. The internal heater 18 is an internal heating section that heats the rod 8 from the inside. The internal heater 18 extends along the axial direction A toward the head 9 at the position of the central axis X of the rod 8. The internal heater 18 extends downstream from an upstream end connected to a power source (not shown), and for example extends into the torpedo 16, heating the torpedo 16 from the inside. As a result, the internal heater 18 heats the resin raw material supplied into the barrel 2 via the torpedo 16. For example, the internal heater 18 reaches a temperature of about 200°C.

[0029] That is, the first heater portion 4a, the second heater portion 4b, the nozzle heater portion 4c, and the internal heater 18 serving as the heater 4 serve as heating portions for heating the resin raw material supplied into the barrel 2.

[0030] The head 9 is provided at the end of the rod 8 on the downstream side, that is, the nozzle 3 side. The head 9 is also called a stopper. The head 9 faces the nozzle 3 in the axial direction A. The head 9 extends in the axial direction A, and the end 9a on the nozzle 3 side has a gear-shaped outer periphery. That is, the end 9a of the head 9 on the nozzle 3 side has a larger outer diameter than the head 9 side, and a plurality of protrusions (fins) are formed on the end 9a in a direction perpendicular to the central axis X.

[0031] The non-return ring 10 is provided between the torpedo 16 and the head 9 and can freely move between them. The non-return ring 10 is provided so as to surround a part of the head 9. The non-return ring 10 prevents the resin stored on the nozzle 3 side from flowing back upstream in the injection process described below.

[0032] The material supply section 11 is a section that supplies material to the inside of the barrel 2, and includes a hopper 30, a cylinder 32, a screw , and a preheater .

[0033] The hopper 30 stores the pellet-like (granular) resin raw material before plasticization, and supplies the resin raw material into the cylinder 32. The cylinder 32 is provided between a supply port 30a of the hopper 30 and a supply port 2d of the barrel 2.

[0034] The screw 34 is provided in the cylinder 32 and can be rotated by a material supply motor (not shown). By the rotation of the screw 34, the resin raw material charged in the cylinder 32 is supplied into the barrel 2 while rotating. The preheater 36 is provided on the outer peripheral surface 32a of the cylinder 32 and is a heating section that heats the resin raw material in the cylinder 32. Since the resin raw material is heated while being stirred, it is preheated with a high heat transfer effect.

[0035] The control device 12 is an information processing device (PLC) that controls the operation of each part in the injection molding machine 1 to perform the injection molding operation. The control device 12 also calculates the filling rate of the resin raw material to be injected. The control device 12 acquires information from various sensors provided in the injection molding machine 1 and executes various processes. The control device 12 is provided with an operation device that may display various statuses and enable the operation of various settings.

[0036] The control device 12 is composed of, for example, a CPU, a memory, a communication interface, a storage device, and the like.

[0037] <Sensor configuration>

[0038] Various sensors are provided in the injection molding machine 1. Specifically, the injection molding machine 1 is provided with a load sensor 51, a position sensor 52, a position sensor 53, and a temperature sensor .

[0039] The load sensor 51 is provided on the rod 8. Specifically, the load sensor 51 is provided on an actuator or a connecting part (not shown) that moves the rod 8. The load sensor 51 detects the load applied to the rod 8. Specifically, in a plasticizing step or a metering step in the injection molding step described later, the resin raw material plasticized by the plunger 6 moves to the nozzle 3 side in the barrel 2 and accumulates in the area between the nozzle 3 and the torpedo 16 (particularly, between the nozzle 3 and the head 9). In the following description, the plasticized resin raw material that accumulates and fills the area between the nozzle 3 and the torpedo 16 is called "filled resin" (filled material). That is, the filled resin accumulated during the injection step is injected from the nozzle 3. In this way, when the filled resin accumulates between the nozzle 3 and the torpedo 16 (specifically, the end 16b), a force is generated by the filled resin that pushes the rod 8 upstream (opposite to the head side) via the head 9. The force of the filled resin pressing against the rod 8 is detected by the load sensor 51 as the load acting from the filled resin to the rod 8. Information detected by the load sensor 51 is output to the control device 12.

[0040] The position sensor 52 is provided for the rod 8. Specifically, the position sensor 52 is provided for an actuator (not shown) that moves the rod 8. The position sensor 52 detects the position of the rod 8 in the moving direction (axial direction A) of the rod 8. Information detected by the position sensor 52 is output to the control device 12.

[0041] The position sensor 53 is provided for the plunger 6. Specifically, the position sensor 53 is provided for an actuator (not shown) that moves the plunger 6. The position sensor 53 detects the position of the plunger 6 in the moving direction of the plunger 6. Information detected by the position sensor 53 is output to the control device 12.

[0042] The temperature sensor 54 is provided for the heater 4. Specifically, the temperature sensor 54 is provided for each of the four heating parts, namely, the first heater part 4a, the second heater part 4b, the nozzle heater part 4c, and the internal heater 18. The first heater part 4a and the second heater part 4b are the first heating part provided for the barrel 2. The nozzle heater part 4c is the second heating part provided for the nozzle 3. The internal heater 18 is the third heating part provided for the rod 8. The temperature sensor 54 may be provided for at least one of the above-mentioned multiple heating parts. For example, the temperature sensor 54 detects the temperature by a thermocouple provided directly or indirectly on the heater 4. Information detected by the temperature sensor 54 is output to the control device 12.

[0043] ≪Functional configuration≫ 2 is a block diagram showing an example of various functions of the control device 12. As shown in FIG. 2, the control device 12 mainly includes an acquisition unit 61, a control unit 62, and a calculation unit 63.

[0044] The acquisition unit 61 acquires detection results from various sensors. Specifically, the acquisition unit 61 acquires detection results from each of four sensors, namely, the load sensor 51, the position sensor 52, the position sensor 53, and the temperature sensor 54. The acquired information is used in the control device 12.

[0045] The control unit 62 controls the injection molding operation in the injection molding machine 1. Specifically, it controls the operation of each unit in each of the steps of a supplying step, a plasticizing step, a measuring step, and an injection step (injection and supplying step) described below, thereby controlling the operation related to injection molding.

[0046] The control unit 62 controls the material supply unit 11 to control the amount of resin raw material before plasticization to be supplied to the barrel 2. Specifically, the supply amount of the resin raw material to be supplied is set based on the filling amount calculated by the calculation unit 63 described later, and the material supply unit 11 is controlled. Since the filling amount indicates the amount of filled resin injected from inside the barrel 2, for example, the supply amount of the resin raw material to be supplied is set so as to compensate for the amount of filled resin injected. For example, since the resin raw material before plasticization is in the form of pellets and has gaps, the supply amount is set taking these gaps into consideration.

[0047] The calculation unit 63 calculates information about the amount of filled resin based on the detection results from the various sensors. In this embodiment, a case where the information about the amount of filled resin is the filling rate of the filled resin will be described as an example. The filling rate indicates what percentage of a predetermined volume has been filled as plasticized resin raw material. Therefore, the filling rate is information that indicates the amount of filled resin.

[0048] The calculation unit 63 calculates the filling rate using a predetermined formula, for example, the following formula (1).

[0049] [Number 1] PV=fRT (1)

[0050] In formula (1), P is pressure, V is volume, f is filling rate, R is a constant (coefficient), and T is temperature. That is, formula (1) becomes a relational equation that indicates the state of the filled resin by setting R to the filled resin.

[0051] The calculation unit 63 sets P in the formula (1) based on the detection result of the load sensor 51. Specifically, P is set based on the load applied from the filled resin to the rod 8 when the plunger 6 is pushed in, that is, the load applied to the rod 8 in the upstream direction.

[0052] The detection result of the load sensor 51 may be used, for example, by monitoring the load change during the process of the plasticization process and the metering process described later. The process of the plasticization process and the metering process is from when the plunger 6 starts to be pushed in until the torpedo 16 reaches the set measurement position and reaches the set pressure. The pressure is the back pressure. For example, the back pressure is detected by a pressure sensor (different from the load sensor 51) installed in the piping to detect the hydraulic pressure of an actuator (not shown) that moves the rod 8. By monitoring the parameter change during the process in this way, the calculation unit 63 can sequentially calculate, for example, the filling rate of the resin accumulated during the process of the plasticization process and the metering process. Specifically, the increasing filling rate is calculated sequentially. When monitoring the parameter change, the change in a parameter other than the load may be monitored.

[0053] The calculation unit 63 sets V in formula (1) based on the detection result of the position sensor 52. Specifically, the calculation unit 63 calculates the volume of the space between the nozzle 3 and the torpedo 16 from the position of the rod 8 in the detection result of the position sensor 52, and sets it as V.

[0054] The calculation unit 63 sets R in formula (1) according to the type of filled resin. In addition, it is preferable that the calculation unit 63 sets R based on the detection result of the position sensor 53 indicating the position of the plunger 6. For example, the closer the position of the plunger 6 is to the nozzle 3 based on the detection result of the position sensor 53, the lower the value of R is calculated to be.

[0055] The calculation unit 63 sets T in formula (1) based on the detection result of the temperature sensor 54. Specifically, T is set based on the respective detected temperatures of the first heater unit 4a, the second heater unit 4b, the nozzle heater unit 4c, and the internal heater 18. For example, an average value or a median value may be calculated based on the respective detected temperatures of the first heater unit 4a, the second heater unit 4b, the nozzle heater unit 4c, and the internal heater 18 and used as T, or the temperature of the filled resin may be estimated based on the respective detected temperatures and used as T.

[0056] When P, V, R, and T are set using the detection results of each sensor, the calculation unit 63 calculates a parameter indicating the filling rate as f based on formula (1). Note that instead of f as the filling rate, a parameter indicating information regarding the filling amount of the filled resin may be used, and the parameter may be calculated from P, V, R, and T in the same manner as above.

[0057] In this manner, the calculation unit 63 calculates the filling rate of the filled resin using the detection results of each sensor.

[0058] <Injection molding process> Next, the steps of injection molding of a resin raw material using the injection molding machine 1 will be described with reference to Figures 3 to 6. Figures 3 to 6 are schematic cross-sectional views of the injection molding machine 1 in Figure 1, and are conceptual diagrams showing each step of injection molding using the injection molding machine 1. Although not shown, it is assumed that a mold for injecting a plasticized resin raw material is actually attached to the nozzle 3.

[0059] (1st process: supply process) Fig. 3 is a conceptual diagram showing the first step of injection molding using the injection molding machine 1 of Fig. 1. In the first step (supply step), a predetermined amount of pellet-shaped resin raw material R is supplied from the supply port 2d of the barrel 2 to between the plunger 6 and the torpedo 16 by the material supply unit 11. The plunger 6 is located upstream of the barrel 2 in the axial direction A, and the supply port 2d of the barrel 2 is in an open state. Then, the process proceeds to the second step.

[0060] (Second step: plasticization step) FIG. 4 is a conceptual diagram showing the second step of injection molding using the injection molding machine 1 of FIG. 1. In the second step (first plasticization step), the plunger 6 is moved from the upstream side to the downstream side, and the supply port 2d of the barrel 2 is closed by the plunger 6. Note that back pressure is applied to the rod 8. The resin raw material R pushed in by the plunger 6 is heated and plasticized by the first heater section 4a, the second heater section 4b, and the internal heater 18. Then, the resin raw material R passes through the gap between the end 16b of the torpedo 16 and the inner peripheral surface 2b of the barrel 2, and then passes through the gap between the check ring 10 and the head 9 to move downstream of the head 9, that is, to the nozzle 3 side of the barrel 2. Then, the filled resin J that has been plasticized and is in a state that can be used for molding is accumulated at the tip of the nozzle 3 side downstream of the torpedo 16 in the barrel 2. The internal pressure of this accumulated filled resin J pushes the torpedo 16 (rod 8) up upstream. That is, the torpedo 16 is pushed back in the opposite direction to the nozzle 3. The pushed back position of the torpedo 16 depends on factors such as the type of pellets, the filling rate of the pellets, the dissolving speed, and the viscosity of the liquid phase. The pushing position of the plunger 6 and the pushed back position of the torpedo 16 depend on these factors. For example, when pellets are formed of small particles, are easily dissolved, and have a filling rate of about 80%, the force pushing up the torpedo 16 (rod 8) as the filling resin is stronger than when pellets are formed of large particles, are difficult to melt, and have a filling rate of about 65%. That is, even if the pushing position by the plunger 6 is the same, the force pushing up the torpedo 16 (rod 8) may differ. Then, the process proceeds to the third step.

[0061] (3rd process: Weighing process) Fig. 5 is a conceptual diagram showing the third step of injection molding using the injection molding machine 1 of Fig. 1. In the third step (measurement step), the position of the torpedo 16 is controlled so that the filled resin J, which is the plasticized resin raw material R accumulated on the nozzle 3 side of the head 9, becomes a set amount. The position of the torpedo 16 is stopped at a position where the set amount of filled resin J required for injection molding has accumulated. In addition, the plunger 6 is moved upstream to the raised end to suck back the rod 8. By sucking back, the internal pressure of the resin J is reduced. Then, the process proceeds to the fourth step.

[0062] (4th process: injection process) Fig. 6 is a conceptual diagram showing the fifth step of injection molding using the injection molding machine 1 of Fig. 1. In the fourth step (injection step), the rod 8 is moved downstream, and the filled resin J stored on the nozzle 3 side is injected toward the mold from the nozzle hole 3a of the nozzle 3. The filled resin J is heated by the nozzle heater section 4c and maintained in a plasticized state. Then, a holding pressure is applied to hold the resin J filled in the mold so that it does not flow back into the injection molding machine 1.

[0063] In the injection process, the position of the plunger 6 is moved to open the supply port 2d of the barrel 2, so that the resin raw material R before plasticization is supplied for the next injection together with the injection. When the supply is performed together with the injection in this way, the injection process is called an "injection and supply process."

[0064] Once the filled resin J has been injected, the process moves to a cooling process for the resin filled in the mold, and after cooling is complete, the mold is opened and the molded product is removed, completing one molded product. Once the injection of the filled resin J and the supply of the raw resin R are complete, the process moves to the second process during the cooling process, and each process is repeated. In this way, molded products are produced continuously.

[0065] In the above example, injection and supply are performed in parallel in the fourth step, but injection may be performed (without supply) in the fourth step, and then the process may return to the first step and each step may be repeated.

[0066] <Processing flow> 7 is a flow chart showing an example of the flow of injection molding according to this embodiment. Each process of the following steps is started, for example, when an operator issues an instruction to execute the process. Note that the order and contents of each step can be changed as appropriate.

[0067] (Step SP10) The control unit 62 starts the supplying step (first step), and proceeds to step SP11.

[0068] (Step SP11) The control unit 62 starts the plasticizing process and the measuring process. Specifically, the control unit 62 starts the plasticizing process, and then starts the measuring process. The process proceeds to step SP12.

[0069] (Step SP12) The acquisition unit 61 acquires detection results from various sensors. Specifically, the acquisition unit 61 acquires detection results from each of the four sensors, namely, the load sensor 51, the position sensor 52, the position sensor 53, and the temperature sensor 54. The process proceeds to step SP13 and step SP14.

[0070] (Step SP13) The control unit 62 completes the plasticizing step and the measuring step, and proceeds to step SP15.

[0071] (Step SP14) The calculation unit 63 calculates the filling rate of the filled resin based on the detection results from the various sensors. The process proceeds to step SP15. Note that, although the example of step SP14 being processed in parallel with step SP13 has been given, the present invention is not limited to this case.

[0072] (Step SP15) The control unit 62 starts the injection and supply process, and proceeds to step SP16.

[0073] (Step SP16) The control unit 62 sets the supply amount of the resin raw material based on the filling rate calculated in step SP14, and supplies the resin raw material. In step SP16, the filling rate calculated in the immediately preceding step SP14 is used. The process proceeds to step SP17.

[0074] (Step SP17) The control unit 62 completes the injection and supply process, and then proceeds to step SP11, where the process is repeated from step S11.

[0075] In addition, in the above-mentioned repetitive process, the process may be terminated when a predetermined condition is satisfied, such as when the process has been repeated a predetermined number of times, or the process may be terminated when a stop command is received from the user of the injection molding machine 1.

[0076] <Action and effect> As described above, in this embodiment, the state of the filled resin can be accurately grasped based on the position of the rod 8 in the axial direction A, the load applied to the rod 8 from the filled resin, and the temperature of the heater 4. That is, the calculation accuracy of the information on the filling amount of the filled resin can be improved. For example, even if the type, size, etc. of the resin raw material used changes, the amount of the filled resin can be accurately grasped, and it is possible to suppress excess or shortage of material.

[0077] In addition, by calculating the filling rate of the filled resin as information on the amount of the filled resin, it is possible to accurately grasp how much of the filled resin has accumulated and is being injected.

[0078] In addition, the load acting on the rod 8 is the load that the rod 8 receives from the filled resin when the plasticized resin raw material is pushed out by the plunger 6, and therefore the load due to the filled resin that accumulates during the plasticization process and the weighing process can be detected by the load sensor 51.

[0079] In addition, by using the temperatures of the first heater portion 4a, the second heater portion 4b, the nozzle heater portion 4c, and the internal heater 18, the temperature situation can be grasped more accurately.

[0080] In addition, by setting the amount of pre-plasticized resin raw material to be supplied to barrel 2 based on information regarding the filling amount of the filled resin (filling rate), it is possible to prevent excess or deficiency of the amount of resin raw material in barrel 2.

[0081] <<Variations>> The present invention is not limited to the above-described embodiment. In other words, the above-described specific example may be modified by a person skilled in the art as appropriate, and the modifications may be included in the scope of the present invention as long as they include the features of the present invention. In addition, the elements of the above-described embodiment and the following modifications may be combined to the extent technically possible, and the combinations of these may be included in the scope of the present invention as long as they include the features of the present invention.

[0082] For example, in the above embodiment, an example was given of a case where the filling rate was calculated as information regarding the filling amount of the filled resin, but the information is not limited to the filling rate and other indicators such as the filling amount may be used as long as it is information regarding the filling amount of the filled resin.

[0083] In the above embodiment, the filling rate is calculated by formula (1) using the detection results of each sensor, but the present invention is not limited to the use of formula (1). For example, a formula other than formula (1) may be used, or a calculation method that does not rely on a formula may be adopted. As long as the filling rate (information regarding the filling amount of the filling material) can be calculated using the detection results of each sensor, the calculation may be performed using a method other than formula (1). [Explanation of symbols]

[0084] 1: Injection molding machine 2: Barrel 3: Nozzle 4: Heater (heating part) 4a: First heater section (first heating section) 4b: Second heater section (first heating section) 4c: Nozzle heater section (second heating section) 6: Plunger (extrusion part) 8: Rod 9: Head 12: Control device 16: Torpedo 18: Internal heater (third heating section) 51: Load sensor 52: Position sensor 54: Temperature sensor A: Axial direction J: Filled resin (filling material) R: Resin raw material (molding material)

Claims

1. A hollow barrel extending in one direction; a nozzle provided at one end side of the barrel in the one direction and configured to inject a molding material plasticized within the barrel; an extrusion section that extrudes the molding material supplied inside the barrel toward the nozzle; a rod extending in the one direction of the barrel through the extrusion portion and having a torpedo at an end portion closer to the nozzle than the extrusion portion; a head provided at an end of the rod on the nozzle side; a heating section that heats the molding material supplied into the barrel; a control device that calculates information about the amount of the plasticized molding material filled between the torpedo and the nozzle inside the barrel based on the position of the rod in the one direction, the load applied to the rod from the filling material, and the temperature of the heating section; An injection molding machine comprising:

2. 2. The injection molding machine according to claim 1, wherein the control device calculates a filling rate of the filling material as the information on the filling amount of the filling material.

3. 3. The injection molding machine according to claim 1, wherein the load acting on the rod is a load that the rod receives from the filling material when the molding material is extruded as the filling material between the torpedo and the nozzle by the extrusion section.

4. the heating unit includes a first heating unit provided for the barrel, a second heating unit provided for the nozzle, and a third heating unit provided for the rod, The injection molding machine according to claim 1 or 2, characterized in that the control device uses the temperatures of the first heating section, the second heating section, and the third heating section as the temperatures of the heating sections, and calculates information regarding the filling amount of the filling material.

5. 3. The injection molding machine according to claim 1, wherein the control device sets a supply amount of the molding material before plasticization to be supplied to the barrel based on information regarding a filling amount of the filling material.

6. A hollow barrel extending in one direction; a nozzle provided at one end side of the barrel in the one direction and configured to inject a molding material plasticized within the barrel; an extrusion section that extrudes the molding material supplied inside the barrel toward the nozzle; a rod extending in the one direction of the barrel through the extrusion portion and having a torpedo at an end portion closer to the nozzle than the extrusion portion; a head provided at an end of the rod on the nozzle side; a heating section that heats the molding material supplied into the barrel; A temperature sensor for detecting a temperature of the heating unit; a position sensor for detecting a position of the rod in the one direction; a load sensor that detects a load applied from the plasticized molding material filled between the torpedo and the nozzle inside the barrel to the rod; An injection molding machine comprising:

Images