Method of controlling resin molding apparatus, and resin molding apparatus

Abstract

To provide a method of controlling a resin molding apparatus, and the resin molding apparatus capable of suppressing decrease of operation efficiency.SOLUTION: A resin molding apparatus 20 comprises a measuring holding unit 50 and a molding unit 60. The measuring holding unit 50 measures a resin material in a molten state, and holds the specified amount of resin material measured. The molding unit 60 uses the specified amount of resin material held by the measuring holding unit 50 to mold the resin material into a work piece W including a rotor core. A series of steps including a molding step of molding the resin material by the molding unit 60, and a measuring holding step, after the molding step, of measuring the resin material and holding the resin material by the measuring holding unit 50, is defined as one molding cycle. In the molding cycle executed last out of the predetermined molding cycles repeatedly executed the specified number of times, measuring of the resin material and holding of the resin material by the measuring holding unit 50 are not executed.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a control method for a resin molding apparatus and a resin molding apparatus.

Background Art

[0002] It is often used to mold a resin material onto a motor core of a rotating electrical machine (for example, Patent Document 1). In Patent Document 1, with a magnet accommodated in a magnet accommodation hole of a motor core, a resin material is molded in a gap between the magnet accommodation hole and the magnet. The magnet is fixed to the motor core by this resin material.

[0003] When molding a resin material onto a motor core, a series of steps including an input step, a molding step, and a take-out step, that is, a molding cycle, is repeatedly executed using a resin molding apparatus such as an injection molding machine. In the input step, a motor core with a magnet accommodated in a magnet accommodation hole is put into the resin molding apparatus. In the subsequent molding step, a resin material is molded into the magnet accommodation hole by the resin molding apparatus. In the subsequent take-out step, the motor core is taken out from the resin molding apparatus.

[0004] Also, in such a resin molding apparatus, in preparation for use in the molding step in the next molding cycle, after completion of the molding step in the current molding cycle, a metering and holding step of holding a measured predetermined amount of resin material inside the resin molding apparatus is often executed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the resin molding apparatus, when the operation of the resin molding apparatus is stopped upon suspension of operation or switching of the molded product, a predetermined amount of resin material held inside the resin molding apparatus remains inside the resin molding apparatus in the metering and holding process.

[0007] Therefore, when the resin material used in the molding process is changed or the amount of use of the resin material is changed in accordance with the stop of the operation of the resin molding apparatus, before restarting the operation of the resin molding apparatus, it is necessary to perform a removal operation to remove the resin material remaining inside the resin molding apparatus. In this case, the operation efficiency of the resin molding apparatus is reduced by the amount of such removal work required.

Means for Solving the Problem

[0008] A control method for a resin molding apparatus for solving the above problems is a resin molding apparatus including a metering and holding unit that meters a resin material in a molten state and holds the metered predetermined amount of resin material, and a molding unit that molds a resin material onto a molded product including a motor core using the predetermined amount of resin material held in the metering and holding unit, and a molding process of molding the resin material by the molding unit, and a metering and holding process of performing metering of the resin material and holding of the resin material by the metering and holding unit after the molding process, and a series of processes including these are defined as one molding cycle. In the molding cycle that is executed repeatedly a predetermined number of times, in the last molding cycle that is executed, the metering of the resin material and the holding of the resin material by the metering and holding unit are not performed.

[0009] The resin molding apparatus for solving the above problems includes a metering and holding unit that measures a resin material in a molten state and holds the measured predetermined amount of the resin material, a molding unit that uses the predetermined amount of the resin material held in the metering and holding unit to mold a resin material onto a molded object including a motor core, a cycle execution unit that repeatedly executes a molding cycle in which the molding unit operates and the metering and holding unit operates after the molding of the resin material by the molding unit is completed, and an execution prohibition unit that prohibits the metering of the resin material and the holding of the resin material by the metering and holding unit in the last executed molding cycle among the molding cycles repeatedly executed a predetermined number of times.

[0010] According to the above configuration and the above control method, when the operation of the resin molding apparatus stops, the resin material can be made not to remain in the metering and holding unit of the resin molding apparatus. Thereby, before restarting the operation of the resin molding apparatus, the removal work of removing the unnecessary resin material remaining in the metering and holding unit becomes unnecessary. Therefore, the decrease in the operating efficiency of the resin molding apparatus can be suppressed by the amount of the removal work becoming unnecessary.

Brief Description of Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] (First Embodiment) Hereinafter, a control method for a resin molding apparatus and a first embodiment of the resin molding apparatus will be described with reference to FIGS. 1 to 6.

[0013] <Rotor 10> First, a control method for the resin molding apparatus according to the present embodiment and a rotor manufactured using the resin molding apparatus will be described.

[0014] As shown in FIGS. 1 and 2, the rotor 10 includes a rotor core 11 as a motor core, a plurality of magnets 12, and a plurality of resin materials 13. The rotor 10 is, for example, a rotor used for a magnet-embedded type motor.

[0015] <Rotor Core 11> The rotor core 11 has a substantially cylindrical shape. As shown in FIG. 2, the rotor core 11 is configured, for example, by laminating a plurality of iron core pieces punched from electromagnetic steel sheets. The rotor core 11 has a first end face 11a and a second end face 11b located on opposite sides in the axial direction (hereinafter simply referred to as the axial direction) of the rotor core 11. The rotor core 11 has a central hole 14 into which a shaft (not shown) is inserted and a plurality of magnet accommodation holes 15 in which the magnets 12 are accommodated. The plurality of magnet accommodation holes 15 are formed at intervals in the circumferential direction of the rotor core 11.

[0016] The central hole 14 and the magnet accommodation holes 15 penetrate the rotor core 11 in the axial direction. That is, both the central hole 14 and the magnet accommodation holes 15 open to the first end face 11a and the second end face 11b. As shown in FIG. 1, the cross-sectional shape perpendicular to the axial direction of the magnet accommodation hole 15 is a substantially rectangular shape having a long side and a short side. The cross-sectional shape of the magnet accommodation hole 15 is the same throughout the axial direction.

[0017] <Magnet 12> The magnet 12 is accommodated one by one in one magnet accommodation hole 15. The magnet 12 is fixed to the rotor core 11 via the resin material 13 filled in the magnet accommodation hole 15.

[0018] As shown in FIG. 2, the magnet 12 has an elongated shape that is long in the axial direction. The cross-sectional shape perpendicular to the axial direction of the magnet 12 has a substantially rectangular shape with a long side and a short side. <Resin material 13> The resin material 13 is filled over the entire circumference of the magnet 12, for example, between the inner surface of the magnet accommodation hole 15 and the outer surface of the magnet 12. The resin material 13 is formed of a thermoplastic resin material such as a liquid crystal polymer, for example.

[0019] <Resin molding apparatus 20> Next, the resin molding apparatus 20 according to the present embodiment will be described. The resin molding apparatus 20 is for molding the resin material 13 onto a molded object (hereinafter, work W) including the rotor core 11.

[0020] As shown in FIG. 3, the work W is composed of the rotor core 11 and the magnet 12. Specifically, the work W is in a state where the magnet 12 is accommodated in the magnet accommodation hole 15 of the rotor core 11. In the present embodiment, the work W is placed on the pallet member 16 and the gate plate 17 is attached to the upper part, and then is put into the resin molding apparatus 20.

[0021] As shown in FIG. 4, the resin molding apparatus 20 includes a supply unit 30, a storage unit 40, a metering and holding unit 50, a molding unit 60, and a control unit 70. In the present embodiment, the resin molding apparatus 20 is configured by an injection molding machine.

[0022] <Supply unit 30> The supply unit 30 includes a hopper 31 and an opening / closing unit 32. The hopper 31 stores granular resin material. The hopper 31 is connected to the storage section 40 via the opening / closing section 32. In the present embodiment, when the opening / closing section 32 is opened, the hopper 31 and the storage section 40 communicate with each other. At this time, the resin material in the hopper 31 is supplied to the storage section 40. On the other hand, when the opening / closing section 32 is closed, the communication between the hopper 31 and the storage section 40 is blocked. At this time, the supply of the resin material from the hopper 31 to the storage section 40 is stopped. In the present embodiment, the resin material in the hopper 31 is supplied to the storage section 40 through the operation control of the supply section 30, specifically, the opening / closing section 32.

[0023] <storage section 40> The storage section 40 stores the resin material supplied from the supply section 30 while melting it.

[0024] The storage section 40 includes a cylinder section 41, a heater 43, and a screw 44. The cylinder section 41 has a cylindrical shape. One end in the axial direction of the cylinder section 41 is connected to the supply section 30 and constitutes a supply port for granular resin material. The other end in the axial direction of the cylinder section 41 is connected to the metering and holding section 50. The resin material is stored inside the cylinder section 41. The heater 43 is attached to the outer wall of the cylinder section 41. Through the heating by the heater 43, the resin material in the cylinder section 41 is melted and stored in a molten state. The screw 44 is for sending the resin material in the cylinder section 41 toward the metering and holding section 50 side (the lower side in FIG. 4). In the present embodiment, the resin material in the storage section 40 corresponds to the resin material to be metered by the metering and holding section 50.

[0025] <metering and holding section 50> The metering and holding section 50 measures the molten resin material and holds the measured predetermined amount of resin material.

[0026] The metering and holding section 50 includes a cylinder 51 connected to the storage section 40, a plunger 52 configured to be reciprocally movable inside the cylinder 51, and an actuator 53 for reciprocally moving the plunger 52.

[0027] In this embodiment, when the resin material is metered and held by the metering and holding unit 50, the plunger 52 is moved in the direction of expanding the space in the cylinder 51 (the upward direction in FIG. 4) through the operation control of the actuator 53. Thereby, the molten resin material in the storage unit 40 is sucked into the cylinder 51.

[0028] In this embodiment, the moving amount of the plunger 52 is set according to the specifications of the workpiece W, which is the object to be molded at that time. Specifically, the moving amount of the plunger 52 is set so that the amount of the resin material (hereinafter referred to as the predetermined amount V) used for molding the resin material 13 for one workpiece W is sucked into and held by the cylinder 51 of the metering and holding unit 50.

[0029] In this embodiment, in this way, the metering of the molten resin material by the metering and holding unit 50 is executed, and the metered resin material of the predetermined amount V is held by the same metering and holding unit 50. In this embodiment, when molding the resin material 13 onto the workpiece W, the plunger 52 is moved in the direction of narrowing the space in the cylinder 51 (the downward direction in FIG. 4) through the operation control of the actuator 53. Thereby, the predetermined amount V of the resin material held in the cylinder 51 is injected onto the workpiece W.

[0030] <Molding unit 60> The molding unit 60 is for molding the resin material 13 onto the workpiece W using the predetermined amount V of the resin material held by the metering and holding unit 50.

[0031] The molding unit 60 includes a mold 61 for molding the resin material 13 and a driving device (not shown) for driving the mold 61 to open and close. In this embodiment, the mold 61 is replaceable according to the specifications of the workpiece W, which is the object to be molded. When switching the workpiece W, the mold 61 is replaced with one that matches the specifications of the workpiece W after switching.

[0032] <Control unit 70> The control unit 70 is constituted by, for example, a micro control unit. The control unit 70 includes a processor and a storage unit 71. The storage unit 71 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). Programs and data for control are stored in the storage unit 71.

[0033] The control unit 70 stores various information related to the processing of the workpiece W. An input device 72 is connected to the control unit 70. Through the operation of the input device 72, various information related to the processing of the workpiece W, such as information regarding a predetermined amount V and the number of workpieces W to be processed (hereinafter referred to as the planned processing number), is input to the control unit 70. Further, the control unit 70 counts and stores the number of workpieces W actually processed (hereinafter referred to as the actual processing number).

[0034] A supply unit 30, a storage unit 40, a metering and holding unit 50, and a molding unit 60 are connected to the control unit 70. The control unit 70 performs various calculations based on various information related to the processing of the workpiece W, and executes the operation control of each part (supply unit 30, storage unit 40, metering and holding unit 50, molding unit 60) of the resin molding apparatus 20 based on the calculation results. In the present embodiment, the control unit 70 corresponds to a cycle execution unit and an execution prohibition unit.

[0035] <Control Method of Resin Molding Apparatus 20> Hereinafter, the control method of the resin molding apparatus 20 will be described with reference to FIGS. 5 and 6. FIG. 5 shows the execution procedure of a process (operation control process) related to the operation control of the resin molding apparatus 20. The series of processes shown in the flowchart of FIG. 5 conceptually shows the execution procedure of the operation control process, and the actual process is executed by the control unit 70 as a process at a predetermined cycle.

[0036] As shown in Fig. 5, in this process, first, it is determined whether it is the timing to start the execution of the molding cycle (step S11). If it is not the timing to start the execution of the molding cycle (step S11: NO), this process ends without executing the following processes (steps S12 to S19).

[0037] If it is the timing to start the execution of the molding cycle (step S11: YES), the processes of steps S12 to S19 are executed. First, the loading process is executed (step S12). In the loading process, the work W is loaded into the mold 61 in the mold-open state through the operation control of a loading device (not shown).

[0038] After the loading process, the mold-clamping process is executed (step S13). In the mold-clamping process, the mold-clamping of the mold 61 is executed through the operation control of the driving device. After the mold-clamping process, the molding process is executed (step S14). In the molding process, the mold 61 is held in the mold-clamped state through the operation control of the driving device, and a resin material of a predetermined amount V is injected into the work W through the operation control of the actuator 53. Thereby, the resin material 13 is molded on the work W.

[0039] After the molding process, the pressure-holding and cooling process is executed (step S15). In the pressure-holding and cooling process, the mold 61 is maintained in the mold-clamped state for a predetermined period through the operation control of the driving device. Thereby, the resin material 13 is appropriately cured inside the magnet accommodation hole 15.

[0040] After the pressure-holding and cooling process, the mold-opening process is executed (step S16). In the mold-opening process, the mold-opening of the mold 61 is executed through the operation control of the driving device. After the mold-opening process, the taking-out process is executed (step S17). In the taking-out process, the work W is taken out from the inside of the mold 61 in the mold-open state through the operation control of the loading device.

[0041] After the pressure holding and cooling process, during the period T1 until the last molding cycle among the molding cycles repeatedly executed a predetermined number of times (step S18: NO), the metering holding process is executed (step S19). In this embodiment, for example, when the planned number of processes is "200", the predetermined number of times is set to "200 times", and the number of times corresponding to the planned number of processes is set as the predetermined number of times.

[0042] In the metering holding process, through the operation control of the metering holding unit 50, specifically the actuator 53, the molten resin material in the storage unit 40 is sucked into the cylinder 51 of the metering holding unit 50 by a predetermined amount V and held.

[0043] And during the period T1, when the metering holding process is completed, this process is terminated. That is, the execution of this molding cycle is completed. On the other hand, among the molding cycles repeatedly executed a predetermined number of times, when it becomes the last molding cycle (step S18: YES), without executing the metering holding process (jumping to the process of step S19), this process is terminated. That is, in this embodiment, in the last molding cycle, the execution of this molding cycle is completed without executing the metering holding process.

[0044] <Operation of this Embodiment> The operation of this embodiment will be described. FIG. 6 shows the transition of the amount of resin material held in the metering holding unit 50 in one molding cycle.

[0045] As shown in FIG. 6, during the period T1 until the last molding cycle, in each molding cycle, the charging process (time t11), the mold clamping process (time t12), the molding process (time t13), and the pressure holding and cooling process (time t13 to t14) are executed. Also, during the period T1, after the pressure holding and cooling process, the mold opening process, the metering holding process (time t14), and the take-out process (time t15) are executed.

[0046] Therefore, in the above period T1, as shown by the dashed line L1 in FIG. 6, after the completion of the take-out process, that is, after the completion of the execution of each molding cycle (from time t15), a predetermined amount V of resin material is held in the cylinder 51 of the metering holding unit 50. Then, in the next molding cycle, the molding process (time t13) is executed using the predetermined amount V of resin material held in the metering holding unit 50.

[0047] On the other hand, even in the last molding cycle, similar to the above period T1, the charging process (time t11), the mold clamping process (time t12), the molding process (time t13), the pressure holding and cooling process (time t13 to t14), the mold opening process (time t14), and the take-out process (time t15) are executed.

[0048] However, in the last molding cycle, different from the above period T1, the metering holding process is not executed. In other words, in the last molding cycle, the metering of the resin material by the metering holding unit 50 and the holding of the resin material are prohibited.

[0049] Therefore, in the last molding cycle, as shown by the solid line L2 in FIG. 6, after the completion of the take-out process, that is, after the completion of the execution of the same molding cycle (from time t15), the cylinder 51 of the metering holding unit 50 is in a state where no resin material is held. Thus, in this embodiment, when the operation of the resin molding apparatus 20 stops, that is, at the end of the execution of the last molding cycle, no resin material remains in the resin molding apparatus 20, specifically, in the cylinder 51 of the metering holding unit 50.

[0050] Here, when the operation of the resin molding apparatus 20 stops, the work W may be switched. And due to the switching of the work W, the amount of resin material used in one molding cycle, that is, the amount of resin material held in the cylinder 51 may be changed. In this case, if resin material remains in the cylinder 51 when the operation of the resin molding apparatus 20 stops, in order to change the holding amount of the resin material in the cylinder 51, a removal operation for removing the resin material remaining inside the cylinder 51 is required.

[0051] In this regard, according to the present embodiment, when the resin molding apparatus 20 stops operating, no resin material remains in the cylinder 51. Therefore, even when the amount of resin material used is changed along with the switching of the workpiece W, the operation of removing the resin material in the cylinder 51 becomes unnecessary for this change. Accordingly, the decrease in the operating efficiency of the resin molding apparatus 20 can be suppressed by the amount corresponding to the elimination of the removal operation. Thereby, the production efficiency of the rotor 10 can be improved.

[0052] Also, due to the switching of the workpiece W when the resin molding apparatus 20 stops operating, the type of resin material used in the resin molding apparatus 20 may be changed. In this case, in order to change the type of resin material to be used, it is necessary to remove the resin material remaining in the storage unit 40 and the metering and holding unit 50.

[0053] According to the present embodiment, when the resin molding apparatus 20 stops operating, at least the inside of the cylinder 51 can be made to have no remaining resin material. Therefore, when the type of resin material is changed along with the switching of the workpiece W, although it is necessary to remove the resin material in the storage unit 40, the operation of removing the resin material in the cylinder 51 becomes unnecessary. In this case, since the time required for removing the resin material in the resin molding apparatus 20 can be shortened by the amount corresponding to the elimination of the operation of removing the resin material in the cylinder 51, the decrease in the operating efficiency of the resin molding apparatus 20 can be suppressed. Thereby, the production efficiency of the rotor 10 can be improved.

[0054] <Actions and Effects of the Present Embodiment> The actions and effects of the present embodiment will be described. (1-1) The resin molding apparatus 20 includes a metering and holding unit 50 and a molding unit 60. The metering and holding unit 50 measures the resin material in a molten state and holds the measured predetermined amount V of the resin material. The molding unit 60 uses the predetermined amount V of the resin material held in the metering and holding unit 50 to mold the resin material 13 onto the workpiece W including the rotor core 11. In the control method of the resin molding apparatus 20, a series of steps including a molding step of molding the resin material 13 by the molding unit 60 and a metering and holding step of performing the metering and holding of the resin material by the metering and holding unit 50 after the molding step are defined as one molding cycle. Among the molding cycles repeatedly executed a predetermined number of times, in the last molding cycle executed, the metering and holding of the resin material by the metering and holding unit 50 are not performed.

[0055] According to the present embodiment, when the operation of the resin molding apparatus 20 stops, the resin material can be made not to remain in the metering and holding unit 50 of the resin molding apparatus 20. As a result, before restarting the operation of the resin molding apparatus 20, the removal work of removing the unnecessary resin material remaining in the metering and holding unit 50 becomes unnecessary. Therefore, the decrease in the operation efficiency of the resin molding apparatus 20 can be suppressed by the amount corresponding to the elimination of such removal work. Thereby, the production efficiency of the rotor 10 can be improved.

[0056] (1-2) When the workpiece W is switched during the stop period of the resin molding apparatus 20 after the execution of the last molding cycle, in the last molding cycle, the metering and holding of the resin material by the metering and holding unit 50 are not performed.

[0057] Therefore, even when the usage amount of the resin material is changed or the type of the resin material is changed along with the switching of the workpiece W, the work of removing the resin material in the cylinder 51 for that change becomes unnecessary. Therefore, the decrease in the operation efficiency of the resin molding apparatus 20 can be suppressed by the amount corresponding to the elimination of the removal work.

[0058] (Second Embodiment) Hereinafter, regarding the control method of the resin molding apparatus and the second embodiment of the resin molding apparatus, with a focus on the differences from the first embodiment, it will be described with reference to FIGS. 7 and 8. In the following, the same reference numerals are given to the same elements or corresponding elements as those in the first embodiment, and redundant descriptions are omitted.

[0059] The execution procedure of the operation control process is different between this embodiment and the first embodiment. Hereinafter, the operation control process according to this embodiment will be described. <Operation control process> FIG. 7 shows the execution procedure of the operation control process according to this embodiment. The series of processes shown in the flowchart of FIG. 7 conceptually shows the execution procedure of the operation control process, and the actual process is executed by the control unit 70 as a process at a predetermined cycle.

[0060] As shown in FIG. 7, in this process, when it is the timing to start the execution of the molding cycle (step S11: YES), the processes of steps S12 to S17 and S21 to S25 are executed.

[0061] In this case, the charging process (step S12), the clamping process (step S13), the molding process (step S14), the pressure holding and cooling process (step S15), the mold opening process (step S16), and the taking-out process (step S17) are sequentially executed.

[0062] Also, in this case, during the period in which the molding cycle is repeatedly executed for a predetermined number of times, until the remaining number of executions reaches a predetermined value P (for example, 5) in the period T2 (step S21: NO), the processes of steps S22 and S23 are executed. Note that the period T2 is, for example, the period in which the 1st to 195th molding cycles are executed when the predetermined number of times (the predetermined number of processes) is set to "200".

[0063] In period T2, after the pressure holding and cooling process, a process of permitting the supply of the resin material from the supply unit 30 to the storage unit 40 is executed in accordance with the execution of the mold opening process and the take-out process (step S22). Specifically, in the process of step S22, the opening / closing part 32 is opened or the opening operation of the opening / closing part 32 is continued.

[0064] Also in period T2, after the pressure holding and cooling process, a metering and holding process is executed in accordance with the execution of the mold opening process and the take-out process (step S23). In the metering and holding process, through the operation control of the metering and holding unit 50, specifically the actuator 53, the molten resin material in the storage unit 40 is sucked into the cylinder 51 of the metering and holding unit 50 by a predetermined amount V and held.

[0065] And in period T2, when the metering and holding process is completed, this process ends. That is, the execution of the current molding cycle is completed. On the other hand, in period T3 when the remaining number of execution times becomes a predetermined value P or less (step S21: YES), after the pressure holding and cooling process, a process of stopping the supply of the resin material from the supply unit 30 to the storage unit 40 is executed in accordance with the execution of the mold opening process and the take-out process (step S24). Specifically, in the process of step S24, the opening / closing part 32 is closed or the closing operation of the opening / closing part 32 is continued.

[0066] In period T3, when it is not the last molding cycle (step S25: NO), after the pressure holding and cooling process, a metering and holding process is executed in accordance with the execution of the mold opening process and the take-out process (step S23).

[0067] In this case, when the metering and holding process is completed, this process ends. That is, the execution of the current molding cycle is completed. In period T3, when it is the last molding cycle (step S25: YES), this process ends without executing the metering and holding process. Thus, in this embodiment, the metering and holding process is not executed in the last molding cycle.

[0068] If it is not the timing to start the execution of the molding cycle (step S11: NO), this process ends without executing each of the above-described processes (steps S12 to S17, S21 to S25).

[0069] <Operation of this Embodiment> The operation of this embodiment will be described. Fig. 8 shows the transition of the amount of the resin material stored in the storage unit 40.

[0070] As shown in Fig. 8, in the period T2 until the remaining number of executions of the molding cycle reaches the predetermined value P, in each molding cycle (times t21, t22), the resin material is supplied from the supply unit 30 to the storage unit 40 in a permitted state, and the metering and holding process is executed.

[0071] Therefore, in the period T2, as shown by the broken line L3 in Fig. 8, the storage unit 40 is maintained in a state where a resin material in an amount corresponding to its capacity (hereinafter, equivalent amount Vf) is stored. In this embodiment, the equivalent amount Vf is the same as the amount obtained by multiplying the predetermined amount V for one of a plurality of types of workpieces W (specific workpiece W) by the predetermined value P (Vf = V × P).

[0072] After that, when the remaining number of executions of the molding cycle reaches the predetermined value P (time t23), the supply of the resin material from the supply unit 30 to the storage unit 40 is stopped. And in that state, the metering and holding process is executed. Therefore, as shown by the solid line L4 in Fig. 8, the amount of the resin material stored in the storage unit 40, that is, the remaining amount of the resin material in the storage unit 40, decreases by the predetermined amount V which is the amount of the resin material measured and held by the metering and holding unit 50.

[0073] Thereafter, each time the molding cycle is executed (times t24, t25, t26), the remaining amount of the resin material in the storage unit 40 decreases by the predetermined amount V. And in the example shown in FIG. 8, at the time of execution of the second last molding cycle (time t26), the remaining amount of the resin material in the storage unit 40 becomes "0". As a result, even at the time of execution of the last molding cycle (time t27), the remaining amount of the resin material in the storage unit 40 becomes "0".

[0074] And in the last molding cycle (time t27), the molding process is executed using the predetermined amount V of the resin material held in the metering holding unit 50 in the previous molding cycle. As a result, the amount of the resin material held in the metering holding unit 50 also becomes "0". In the present embodiment, in the last molding cycle, the metering holding process, specifically, the process of moving the plunger 52 in the direction of narrowing the space in the cylinder 51 is not executed.

[0075] In the present embodiment, at the timing when the resin material stored in the storage unit 40 and the resin material held in the metering holding unit 50 are almost used up by the execution of the molding process in the last molding cycle, the supply of the resin material from the supply unit 30 to the storage unit 40 is stopped (time t23).

[0076] Thus, in the present embodiment, when the execution of the last molding cycle is completed, that is, when the operation of the resin molding apparatus 20 stops, the resin material is almost not left in the resin molding apparatus 20, specifically, in the cylinder portion 41 of the storage unit 40 and the cylinder 51 of the metering holding unit 50.

[0077] Here, due to the switching of the workpiece W at the time of stopping the operation of the resin molding apparatus 20, the amount of the resin material used in one molding cycle, that is, the amount of the resin material held in the cylinder 51 may be changed. Also, due to the switching of the workpiece W at the time of stopping the operation of the resin molding apparatus 20, the type of the resin material used in the resin molding apparatus 20 may be changed. In either case, if the resin material remains inside the resin molding apparatus 20 at the time of stopping the operation, in order to change the holding amount and type of the resin material during the operation stop period, a removal operation for removing the resin material remaining inside the resin molding apparatus 20 becomes necessary.

[0078] In this regard, according to the present embodiment, when the resin molding apparatus 20 stops operating, almost no resin material remains in the cylinder portion 41 of the storage portion 40 or the cylinder 51 of the metering and holding portion 50. Therefore, even when the amount of resin material used or the type of resin material is changed along with the switching of the workpiece W, the operation of removing the resin material inside the resin molding apparatus 20 becomes unnecessary or an operation that can be completed in a short time. Accordingly, the decrease in the operating efficiency of the resin molding apparatus 20 can be suppressed by the amount of time reduction in the removal operation. Thereby, the production efficiency of the rotor 10 can be improved.

[0079] Also, when the operation of the resin molding apparatus 20 is stopped due to the suspension of operation, if the resin material remains inside the resin molding apparatus 20, there is a risk that the resin material remaining inside the resin molding apparatus 20 will deteriorate during the subsequent operation stop period. In this case, in order to operate the resin molding apparatus 20 in an appropriate state at the start of operation, a removal operation of removing the resin material remaining inside the resin molding apparatus 20 is required before starting the operation of the resin molding apparatus 20.

[0080] According to the present embodiment, when the resin molding apparatus 20 stops operating, it is possible to make it such that almost no resin material remains inside the cylinder portion 41 of the storage portion 40 or the cylinder 51 of the metering and holding portion 50. Thus, although there is concern about the deterioration of the resin material during the operation stop period of the resin molding apparatus 20, since almost no resin material remains inside the resin molding apparatus 20, the operation of removing the resin material becomes unnecessary or an operation that can be completed in a short time.

[0081] Therefore, according to the present embodiment, even when the operation of the resin molding apparatus 20 is stopped along with the suspension of operation, the time required for the resin molding apparatus 20 to be set can be shortened by the amount of time reduction in the resin material removal operation. Thereby, the decrease in the operating efficiency of the resin molding apparatus 20 can be suppressed, and thus the production efficiency of the rotor 10 can be improved.

[0082] <Operations and Effects of this Embodiment> The operations and effects of this embodiment will be described. (2-1) According to this embodiment, the same operational effects as those described in (1-1) and (1-2) can be obtained.

[0083] (2-2) The resin molding apparatus 20 includes a storage unit 40 and a supply unit 30. The storage unit 40 is connected to the metering and holding unit 50 and stores the resin material to be metered while melting it by the metering and holding unit 50. The supply unit 30 supplies the resin material to the storage unit 40. The resin molding apparatus 20 stops the supply of the resin material to the storage unit 40 by the supply unit 30 at a timing such that the resin material stored in the storage unit 40 and the resin material held by the metering and holding unit 50 are almost completely used up by the execution of the molding process in the last molding cycle.

[0084] According to this embodiment, in the resin molding apparatus 20 having the storage unit 40 for storing the resin material to be metered, when the operation of the resin molding apparatus 20 stops, the resin material can be in a state where almost no resin material remains in the storage unit 40 and the metering and holding unit 50. As a result, the removal work for removing the unnecessary resin material remaining in the storage unit 40 and the metering and holding unit 50 before restarting the operation of the resin molding apparatus 20 becomes unnecessary or an operation that can be completed in a short time. Therefore, the decrease in the operating efficiency of the resin molding apparatus 20 can be suppressed by the amount of time required for the resin material removal work being shortened.

[0085] <Modification Example> Note that each of the above embodiments can be modified and implemented as follows. Each of the above embodiments and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0086] · In the second embodiment, as a process for stopping the supply of the resin material from the supply unit 30 to the storage unit 40, instead of executing the process of closing the opening / closing unit 32, the process of stopping the supply of the resin material to the hopper 31 may be executed. As the process of stopping the supply of the resin material to the hopper 31, for example, when there is a supply device for supplying the resin material to the hopper 31, the process of stopping the operation of the supply device can be executed.

[0087] Even with such a configuration, it becomes possible to stop the supply of the resin material to the storage unit 40 at a timing such that the resin material stored in the storage unit 40 and the resin material held in the metering and holding unit 50 are almost used up by the execution of the molding process in the last molding cycle. In this case, the opening / closing unit 32 can be omitted.

[0088] · In the last molding cycle in the second embodiment, the operation control of the actuator 53 may be executed so as to move the plunger 52 in a direction to expand the space in the cylinder 51. When the last molding cycle is executed, almost no resin material remains in the storage unit 40. Therefore, when the operation control of the actuator 53 is executed in the last molding cycle, the metering of the resin material by the metering and holding unit 50 and the holding of the metered resin material are not executed. That is, also in this case, the metering of the resin material by the metering and holding unit 50 and the holding of the resin material are prohibited.

[0089] · In the second embodiment, the relationship between the capacity (equivalent amount Vf) of the resin material in the storage unit 40 and the predetermined value P can be arbitrarily changed. For example, when the amount of resin material used in one molding cycle (predetermined amount V) is the same for a plurality of types of workpieces W, as the equivalent amount Vf, an amount obtained by multiplying the predetermined amount V by the predetermined value P may be set (Vf = V × P). In this case, no matter which workpiece W is used as the molding target product, the resin material stored in the storage unit 40 and the resin material held in the metering and holding unit 50 can be used up by the execution of the molding process in the last molding cycle.

[0090] In addition, when the amount of resin material used (predetermined amount V) in one molding cycle differs among a plurality of types of workpieces W, it is also possible to set the equivalent amount Vf and the predetermined value P as follows. That is, regardless of which workpiece W is the object to be molded, the equivalent amount Vf and the predetermined value P can be set so that the amount of resin material remaining in the storage unit 40 at the time of stopping the operation of the resin molding apparatus 20 becomes "0" or a small amount.

[0091] · The control method and the resin molding apparatus according to each of the above embodiments can also be applied to a resin molding apparatus that molds a resin material onto a molded object including a stator core. Examples of such a resin molding apparatus include a resin molding apparatus that molds a resin material between a stator core and a winding.

[0092] · The control method and the resin molding apparatus according to each of the above embodiments can also be applied to a resin molding apparatus that molds a resin material made of an adhesive as a resin material onto a molded object including a motor core. Examples of such a resin molding apparatus include a resin molding apparatus that molds a resin material to adhere electromagnetic steel sheets to each other on a molded object formed by laminating electromagnetic steel sheets constituting a motor core.

[0093] · The control method and the resin molding apparatus according to each of the above embodiments can also be applied to a resin molding apparatus of a so-called in-line screw type in which the screw 44 of the storage unit 40 and the cylinder 51 of the metering and holding unit 50 are arranged coaxially.

[0094] · The control method and the resin molding apparatus according to each of the above embodiments can also be applied to a resin molding apparatus that uses a thermosetting resin material.

Description of Reference Numerals

[0095] W... Workpiece V... Predetermined amount 10... Rotor 11... Rotor core 11a... First end face 11b…Second end face 12…Magnet 13…Resin material 14…Central hole 15…Magnet accommodation hole 16…Pallet member 17…Gate plate 20…Resin molding device 30…Supply section 31…Hopper 32…Opening / closing section 40…Storage section 41…Cylinder section 43…Heater 44…Screw 50…Measurement holding section 51…Cylinder 52…Plunger 53…Actuator 60…Molding section 61…Mold 70…Control section 71…Memory section 72…Input device

Claims

1. A resin molding apparatus comprising a metering and holding unit that measures a resin material in a molten state and holds the measured predetermined amount of the resin material, and a molding unit that uses the predetermined amount of the resin material held in the metering and holding unit to mold a resin material onto a molded object including a motor core, and A control method for the resin molding apparatus, which includes a molding step of molding the resin material by the molding unit and a metering and holding step of performing metering and holding of the resin material by the metering and holding unit after the molding step, and defines a series of steps including these as one molding cycle, Among the molding cycles repeatedly executed a predetermined number of times in advance, in the last executed molding cycle, the metering and holding of the resin material by the metering and holding unit are not performed, A control method for a resin molding apparatus.

2. The resin molding apparatus is Connected to the metering and holding unit, and includes a storage unit that stores the resin material to be measured by the metering and holding unit while melting it, And a supply unit that supplies the resin material to the storage unit, At a timing when the resin material stored in the storage unit and the resin material held in the metering and holding unit are used up by the execution of the molding step in the last molding cycle, the supply of the resin material to the storage unit by the supply unit is stopped, The control method for the resin molding apparatus according to Claim 1.

3. When the molded object is switched during the stop period of the resin molding apparatus after the execution of the last molding cycle, in the last molding cycle, the metering and holding of the resin material by the metering and holding unit are not performed, The control method for the resin molding apparatus according to Claim 1 or 2.

4. A metering and holding unit that measures a resin material in a molten state and holds the measured predetermined amount of the resin material, A molding unit that uses the predetermined amount of the resin material held in the metering and holding unit to mold a resin material onto a molded object including a motor core, A cycle execution unit that repeatedly executes a molding cycle in which the molding unit operates and the metering and holding unit operates after the molding of the resin material by the molding unit is completed, Among the molding cycles repeatedly executed a predetermined number of times in advance, in the last executed molding cycle, an execution prohibition unit that prohibits weighing and holding of the resin material by the weighing holding unit, and a resin molding apparatus including the same.

Images