Injection molding machine system

Abstract

To provide an injection molding machine system having a plurality of injection molding machines in which a cost of a power converter is suppressed.SOLUTION: An injection molding machine system 100 that drives a plurality of injection molding machines by using power received from a system power supply 10 comprises: a first injection molding machine 50A and a second injection molding machine 50B; a first power storage device 55A and a second power storage device 55B; and a power supply device 25 which converts power received from the system power supply 10, and supplies the power after converted to at least one of the first power storage device and the second power storage device. The power supply device includes: an AC / DC converter 20 which converts AC power into DC power; a DC / DC converter 31 which converts voltage of DC power; a switching device 41 which is constituted to be capable of switching a supply route; and a controller 80. The controller switches the switching device on the basis of SOC of each of the first power storage device and the second power storage device.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an injection molding machine system.

Background Art

[0002] In factories, molded products made of resins such as plastics are manufactured using injection molding machines. For injection molding processes that require precise positioning control, servo motors with high precision and responsiveness can be used. Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-168177) describes an electric injection molding machine having a servo motor.

[0003] In Patent Document 1, AC power supplied from a three-phase AC power supply is converted into DC power by an AC / DC converter and supplied to the servo motor of the electric injection molding machine. The AC / DC converter controls the current supplied from the three-phase AC power supply in a sine wave shape and outputs a predetermined DC voltage. Patent Document 1 discloses a configuration in which one AC / DC converter is provided for one injection molding machine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in some cases, a system including a plurality of injection molding machines may be introduced into a factory. In such a system, if one AC / DC converter is provided for each injection molding machine, the same number of AC / DC converters as the plurality of injection molding machines is required. When the same number of power converters as the number of the plurality of injection molding machines is provided, the cost of the entire system may increase.

[0006] This disclosure was made to solve these problems, and its purpose is to reduce the cost of power converters in an injection molding machine system having multiple injection molding machines. [Means for solving the problem]

[0007] An injection molding machine according to one embodiment is an injection molding machine system that drives a plurality of injection molding machines using power received from a grid power source. The injection molding machine system comprises a first injection molding machine, a second injection molding machine, a first energy storage device, a second energy storage device, and a power supply device. The first injection molding machine is driven by a supply of DC power. The second injection molding machine is driven by a supply of DC power. The first energy storage device is configured to supply DC power to the first injection molding machine and to store DC power. The second energy storage device is configured to supply DC power to the second injection molding machine and to store DC power. The power supply device converts the power received from the grid power source and supplies the converted power to at least one of the first energy storage device and the second energy storage device. The power supply unit includes a first power converter that converts AC power received from the grid power supply into DC power, a second power converter that converts the voltage of the DC power converted by the first power converter, a switching device configured to switch supply paths for supplying the DC power converted by the second power converter to at least one of the first and second energy storage devices, and a control device that controls the switching device. The control device switches the switching device based on the State of Charge (SOC) of each of the first and second energy storage devices. [Effects of the Invention]

[0008] According to the injection molding machine described herein, in an injection molding machine system having a first injection molding machine and a second injection molding machine, power can be supplied to each of the multiple injection molding machines using a single second power converter, thereby reducing costs. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a schematic configuration of the injection molding machine system in Embodiment 1. [Figure 2]This is an external view of the injection molding machine in Embodiment 1. [Figure 3] This is a schematic block diagram of the injection molding machine in Embodiment 1. [Figure 4] This flowchart shows the switching procedure of the switching device in Embodiment 1. [Figure 5] This flowchart shows the switching procedure of the switching device in modified example 1. [Figure 6] This flowchart shows the switching procedure of the switching device in modified example 2. [Figure 7] This figure shows a schematic configuration of the injection molding machine system in Embodiment 2. [Figure 8] This figure shows a schematic configuration of the injection molding machine system in Embodiment 3. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. [Embodiment 1] <About the configuration of the injection molding machine system> The injection molding machine system 100 in Embodiment 1 will be described below with reference to Figure 1. Figure 1 is a schematic diagram of the configuration of the injection molding machine system 100 in Embodiment 1.

[0011] The injection molding machine system 100 in Embodiment 1 comprises a power supply unit 25, injection molding machines 50A to 50D, and batteries 55A to 55D. The power supply unit 25 converts the power received from the grid power supply 10 and supplies the converted power to at least one of the batteries 55A to 55D.

[0012] Each of the injection molding machines 50A to 50D is a horizontal injection molding machine having a mold clamping device and an injection device. Hereinafter, the injection molding machines 50A to 50D are collectively referred to simply as "injection molding machine 50". Note that the number of injection molding machines 50 included in the injection molding machine system 100 in the first embodiment is not limited to five, and the injection molding machine system 100 may include two or more injection molding machines.

[0013] The injection molding process performed by the injection molding machine 50 includes processes such as a mold clamping process, an injection process, a holding pressure process, a cooling process, a mold opening process, a protruding process, and a plasticizing process. The injection molding machine 50 repeatedly executes the cycle of this injection molding process. The injection molding machine 50 can mold molded products of various shapes and materials, and performs an injection molding process according to the types of shape and material.

[0014] The injection molding machine 50 includes a servo motor used in the injection molding process and a servo amplifier that drives the servo motor. The servo amplifier generates a three-phase AC voltage from a DC voltage and drives the servo motor. That is, the injection molding machine 50 performs an injection molding process using the DC power received from the power supply device 25. The configuration and operation of the injection molding machine 50 will be described later.

[0015] Batteries 55A to 55D are respectively connected to the injection molding machines 50A to 50D. The batteries 55A to 55D respectively supply DC power to the injection molding machines 50A to 50D. The batteries 55A to 55D are DC power sources configured to be rechargeable, and are, for example, secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries including solid or liquid electrolytes. Note that the batteries 55A to 55D may be respectively stored inside the injection molding machines 50A to 50D. Hereinafter, the batteries 55A to 55D may be collectively referred to simply as "battery 55".

[0016] The power supply device 25 includes an AC / DC converter 20, DC / DC converters 21 and 31, a battery 22, a switching device 41, a control device 80, and a storage device 90.

[0017] The AC / DC converter 20 is electrically connected to the terminals of the power supply device 25 that receives AC power from the utility power supply 10. The AC / DC converter 20 and the DC / DC converters 21, 31 are electrically connected via the power line 35. A battery 22 is connected to the DC / DC converter 21. The DC / DC converter 31 is connected to the terminals of the power supply device 25 on the side connected to the injection molding machine 50 via the switching device 41.

[0018] The AC / DC converter 20 is a power converter that converts the AC power supplied from the utility power supply 10 into DC power. The DC power generated by the AC / DC converter 20 is supplied to the DC / DC converters 21, 31 via the power line 35. That is, DC power flows through the power line 35. The AC / DC converter 20 is an example of the "first power converter" in the present disclosure.

[0019] The battery 22 is a secondary battery such as a lithium-ion battery, similar to the battery 55. The DC / DC converter 21 steps down the power supplied from the power line 35 and supplies it to the battery 22. Also, the DC / DC converter 21 steps up the voltage of the power supplied from the battery 22 and generates the power supplied to the power line 35. Thereby, in the injection molding machine system 100, when the power supply from the utility power supply 10 is restricted due to a disaster or power shortage, etc., it is possible to temporarily supply power to the injection molding machines 50A to 50D using the battery 22.

[0020] The DC / DC converter 31, like the DC / DC converter 21, steps down the power supplied from the power line 35 and supplies it to the injection molding machine 50 or the battery 55. That is, the DC / DC converter 31 steps down the output voltage of the AC / DC converter 20 to generate power to supply to the batteries 55A~55D and the driving power of the injection molding machine 50. The DC / DC converter 31 is an example of a "second power converter" in this disclosure. The DC / DC converter 31 in Embodiment 1 is an isolated DC / DC converter. That is, the DC / DC converter 31 includes an isolation transformer. This allows the primary and secondary sides of the DC / DC converter 31 to be isolated, so that even if a ground fault occurs in the injection molding machine 50, the ground fault does not affect the primary side of the DC / DC converter 31.

[0021] The switching device 41 switches the supply path for the DC power stepped down by the DC / DC converter 31. The switching device 41 is, for example, a relay circuit. The switching device 41 can switch the supply path so that the DC power generated by the DC / DC converter 31 is supplied to at least one of the batteries 55A to 55D. For example, the switching device 41 can switch the supply path so that the DC power generated by the DC / DC converter 31 is supplied only to battery 55A. Alternatively, the switching device 41 can switch the supply path so that the DC power generated by the DC / DC converter 31 is supplied to two batteries, battery 55A and battery 55B. Note that the switching device 41 may correspond to the "first switching device" in this disclosure.

[0022] Furthermore, the switching device 41 can switch the supply path so that the DC power generated by the DC / DC converter 31 is supplied to all of the batteries 55A to 55D. For example, in a factory where the injection molding machines 50A to 50D are shut down at night, the control device 80 switches the supply path so that DC power is supplied to all of the batteries 55A to 55D at night. This allows the injection molding machine system 100 to charge all of the batteries 55A to 55D at night.

[0023] As described above, the control device 80 controls the switching device 41. The control device 80 is implemented, for example, by one or more processors such as a CPU, or by a combination of a processor and circuits such as an ASIC or FPGA. In Embodiment 1, the control device 80 acquires the State of Charge (SOC) of each of the batteries 55A to 55D and controls the switching device 41 based on the acquired SOC. More specifically, in Embodiment 1, the control device 80 controls the switching device 41 so that DC power is supplied to the battery with the lowest SOC among the batteries 55A to 55D.

[0024] Furthermore, in Embodiment 1, the control device 80 can obtain the power consumption of each of the injection molding machines 50A to 50D. As described above, the injection molding machine 50 performs different injection molding processes depending on the shape and material of the molded product. For example, the motor drive time in one cycle of the injection molding process, the torque required depending on the shape and material of the molded product, etc., differ. Therefore, the power consumption of each injection molding machine 50 differs depending on the shape and material of the molded product.

[0025] The memory device 90 is a non-volatile memory device. The control device 80 can store in the memory device 90 the State of Charge (SOC) acquired from each of the batteries 55A to 55D and the power consumption acquired from each of the injection molding machines 50A to 50D. In other words, the memory device 90 stores the history of the SOC of each of the batteries 55A to 55D and the power consumption of each of the injection molding machines 50A to 50D. <Injection molding machine> The injection molding machine 50 in Embodiment 1 will be described below with reference to Figure 2. Figure 2 is an external view of the injection molding machine 50 in Embodiment 1. The injection molding machine 50 includes a mold clamping device 60 for clamping the mold, an injection device 61 for melting and injecting the injection material, a display device 30, and a control device 40.

[0026] The injection molding machine 50 is mounted on the XY plane. The direction perpendicular to the XY plane is defined as the Z-axis direction. In Figure 2, the positive direction of the Z-axis is sometimes referred to as the top side or upward, and the negative direction as the bottom side or downward.

[0027] <Mold clamping device> In Embodiment 1, the clamping device 60 comprises a bed 11, a fixed platen 12, a clamping housing 13, a movable platen 14, a tie bar 15, a clamping mechanism 16, molds 17 and 18, and a ball screw 51. The bed 11 holds the components of the clamping device 60, such as the fixed platen 12, the clamping housing 13, and the movable platen 14. The fixed platen 12 is fixed to the bed 11. The clamping housing 13 is configured to slide on the bed 11 in the X-axis direction. Similarly, the movable platen 14 is configured to slide on the bed 11 in the X-axis direction.

[0028] The tie bar 15 is positioned between the fixed platen 12 and the clamping housing 13, connecting the fixed platen 12 and the clamping housing 13. The tie bar 15 includes multiple bars. The injection molding machine 50 in Embodiment 1 is equipped with a tie bar 15 that includes four bars. In some aspects, the tie bar 15 may include five or more bars.

[0029] The movable platen 14 is configured to slide in the X-axis direction between the fixed platen 12 and the clamping housing 13. The clamping mechanism 16 is provided between the clamping housing 13 and the movable platen 14. In Embodiment 1, the clamping housing 13 is configured to include a toggle mechanism. The clamping mechanism 16 may also be configured to include a direct-pressure type clamping mechanism. A direct-pressure type clamping mechanism means a clamping cylinder.

[0030] The molds 17 and 18 are placed between the fixed platen 12 and the movable platen 14. The molds 17 and 18 are configured to open and close when the clamping mechanism 16 is driven. The ball screw 51 converts rotational motion into linear motion, thereby opening and closing the clamping mechanism 16. <Injection device> The injection device 61 comprises a base 62, a heating cylinder 63, a screw 23, a drive mechanism 24, a hopper 64, an injection nozzle 26, a nozzle touch device 27, and a thermocouple 65. The base 62 is positioned on the positive X-axis side of the bed 11 and holds the drive mechanism 24, etc. The screw 23 is positioned inside the heating cylinder 63. The drive mechanism 24 rotates the screw 23 with the X-axis direction as its central axis and drives the screw 23 itself to slide in the X-axis direction.

[0031] The hopper 64 is located on the positive Z-axis side of the heating cylinder 63. The injection nozzle 26 is located at the negative X-axis end of the heating cylinder 63. The nozzle touch device 27 slides the injection device 61 in the X-axis direction to bring the injection nozzle 26 into contact with the sprue bush of the mold 18. Thermocouples 65 may be placed near the injection nozzle 26 and near the heating cylinder 63. The thermocouples 65 are temperature sensors that detect the temperature at the location where they are placed. In some cases, the injection molding machine 50 may be equipped with temperature sensors other than thermocouples 65.

[0032] The base 62 houses a control device 40 and servo amplifiers 53a and 53b. The control device 40 includes a circuit board 52 equipped with a CPU, memory, etc. The control device 40 acquires detection values ​​from various sensors, including thermocouples 65, and comprehensively controls the injection molding machine 50. The detection values ​​from the various sensors include, for example, temperature information from the heating cylinder 63, or position information from various movable parts such as the clamping mechanism 16, molds 17 and 18, and injection nozzles 26.

[0033] As described above, servo amplifiers 53a and 53b generate a three-phase AC voltage from a DC voltage and supply three-phase AC power to the corresponding servo motor. Servo amplifiers 53a and 53b are of the same type.

[0034] The display device 30 is located on the negative side of the Y-axis of the injection molding machine 50. However, the placement of the display device 30 is not limited to the negative side of the Y-axis of the injection molding machine 50; for example, it may be located on the positive side of the Y-axis of the injection molding machine 50 or as a separate unit from the injection molding machine 50. The display device 30 comprises a display 30D and an input device 30B. The input device 30B is configured, for example, to include a plurality of buttons. In some cases, the display device 30 may include a plurality of displays and speakers, etc. Furthermore, the display 30D and the input device 30B may be integrated as a touch panel. Although Figure 2 illustrates an example of a horizontal injection molding machine, the injection molding machine 50 of Embodiment 1 is not limited to this and may be a vertical injection molding machine. <Schematic block diagram of an injection molding machine> Figure 3 is a schematic block diagram of the injection molding machine 50. The control device 40 comprises a storage unit 44 and a circuit board 52. The storage unit 44 may be configured to include, for example, an HDD (Hard Disk Drive) or an SSD (Flash Solid State Drive). The circuit board 52 is equipped with a control unit 57, an input interface 52i, and an output interface 52o. The control unit 57 comprises a CPU 57a and a memory 57b.

[0035] Memory 57b includes ROM (Read Only Memory) and RAM (Random Access Memory) and stores programs executed by CPU 57a. CPU 57a loads the programs stored in ROM into RAM and executes them.

[0036] In certain situations, the control unit 57 may be configured with a dedicated hardware circuit. That is, the control unit 57 can be implemented using an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like. Alternatively, the control unit 57 may be implemented using an appropriate combination of a processor, memory, ASIC, FPGA, etc.

[0037] The control unit 57 receives detection values ​​from various sensors, such as thermocouples 65, via the input interface 52i. The control unit 57 transmits control commands to the drive mechanism 24 and the display device 30 via the output interface 52o. The control unit 57 drives the drive mechanism 24 using the detection values ​​from the various sensors. The control unit 57 displays the status of the injection molding machine 50 on the display device 30 based on the detection values ​​from the various sensors.

[0038] <Processing Procedure in Control Device> The processing in the control device 80 of the injection molding machine system 100 according to Embodiment 1 will be described below. Figure 1 will also be referenced as appropriate in the following description of the processing in the control device 80. Figure 4 is a flowchart showing the switching procedure of the switching device 41 in the control device 80. The flowchart shown in Figure 4 is stored as a program in the storage device 90 and executed by the control device 80.

[0039] The control device 80 acquires the State of Charge (SOC) of each of the batteries 55A to 55D (step S10). More specifically, the control device 80 estimates and acquires the SOC of each of the batteries 55A to 55D based on the detection values ​​of current sensors or voltage sensors (not shown) provided on each of the batteries 55A to 55D. The control device 80 compares the acquired SOCs of each of the batteries 55A to 55D (step S11). The control device 80 determines that the battery 55 with the lowest SOC is the supply destination (step S12). The control device 80 switches the switching device 41 so that DC power is supplied to the battery 55 designated as the supply destination (step S13).

[0040] The control device 80 charges the battery 55, which was designated as the power source in step S13, for a predetermined period of time (step S14). The predetermined period in step S14 may be, for example, 1 minute, 10 seconds, or even a shorter time. In Embodiment 1, the injection molding machine 50 is basically driven based on the power supplied from the battery 55. If the injection molding machine 50 is running in step S14, the control device 80 supplies DC power to both the power source battery 55 and the injection molding machine 50. As a result, the injection molding machine system 100 can drive the injection molding machine 50 with DC power received from the power supply unit 25, and at the same time charge the battery 55 with power supplied from the power supply unit 25. In other words, the power supplied by the power supply unit 25 is greater than the power consumed by the battery 55 by the injection molding machine 50.

[0041] The control device 80 determines whether all batteries 55A to 55D are fully charged (step S15). If not all batteries are fully charged (NO in step S15), the control device 80 returns to step S10. This allows the control device 80 to switch the battery supply destination at predetermined intervals in step S14 and perform the charging process. In other words, the control device 80 performs the charging process using time division. If all batteries are fully charged (YES in step S15), the control device 80 terminates the process. After terminating the process, the control device 80 executes the flowchart in Figure 4 again, based on the fact that a predetermined period has elapsed, power has been supplied from batteries 55A to 55D to the injection molding machine 50, or the injection molding machine 50 has been driven.

[0042] Thus, in the injection molding machine system 100 having five injection molding machines 50A to 50D, the DC power supply path is switched based on the State of Charge (SOC) of each battery 55A to 55D. In other words, in the injection molding machine system 100 of Embodiment 1, the DC / DC converter 31 performs the power supply processing to each battery 55A to 55D in a time-division manner. As a result, in the injection molding machine system 100 of Embodiment 1, it is not necessary to provide a DC / DC converter 31 for each of the five injection molding machines 50A to 50D, so power can be supplied by a single DC / DC converter 31, thereby reducing costs.

[0043] <Example 1> The flowchart of Embodiment 1 describes an example in which the battery with the lowest SOC among the batteries 55A to 55D shown in Figure 1 is selected as the supply destination. However, the method for determining the supply destination is not limited to comparing the SOCs at the time the SOC is acquired; the control device 80 may also determine the supply destination using the history stored in the storage device 90. Modification 1 describes an example in which the supply destination is determined using the amount of SOC decrease per unit time in addition to comparing the SOCs. Figure 1 will also be referred to as appropriate in the following description of Modification 1. Furthermore, in Modification 1, the same configuration as that described in Embodiment 1 in Figures 1 to 4 will not be repeated.

[0044] Figure 5 is a flowchart showing the switching procedure of the switching device 41 in modified example 1. The control device 80 acquires the State of Charge (SOC) of each of the batteries 55A to 55D (step S20). In step S20, the control device 80 associates each acquired SOC with information indicating the time of acquisition and stores it in the storage device 90 as history.

[0045] The control device 80 compares the State of Charge (SOC) of each battery 55A to 55D, and the rate of decrease per unit time of the SOC of each battery 55A to 55D (step S21). The rate of decrease is the value obtained by subtracting the power charged by the power supply unit 25 from the power supplied from battery 55 to the injection molding machine 50. If no power is supplied from the power supply unit 25, the rate of decrease becomes the power supplied to the injection molding machine 50 itself.

[0046] The control device 80 calculates the rate of decrease per unit time of each of the batteries 55A to 55D's State of Charge (SOC) based on the history stored in the storage device 90. In the modified example 1, the unit time is a very small amount of time in order to calculate the slope of the SOC change. However, the unit time is not limited to a very small amount of time; in a given situation, the unit time may be 10 seconds, 1 minute, or other periods.

[0047] The control device 80 determines which battery 55 will be supplied to which the SOC falls below a predetermined reference value the earliest, based on a comparison between the SOC and the rate of decrease in SOC per unit time (step S22). The predetermined reference value is, for example, the lower limit of the normal operating range or the SOC value indicating an over-discharge state. The lower limit of the normal operating range is, for example, 20%.

[0048] In other words, the control device 80 estimates that the State of Charge (SOC) of each battery 55A to 55D will continue to decrease at the rate of decrease per unit time calculated in step S21, and calculates the period from the timing in step S22 until the SOC of each battery 55A to 55D reaches the lower limit of the normal operating range. The control device 80 determines the battery 55 that will reach the lower limit of the normal operating range earliest as the supply destination.

[0049] The control device 80 switches the switching device 41 so that DC power is supplied to the battery 55 designated as the power supply destination (step S23). The control device 80 charges the battery 55 designated as the power supply destination in step S23 for a predetermined period of time (step S24). The control device 80 determines whether all of batteries 55A to 55D are fully charged (step S25). If not all batteries are fully charged (NO in step S25), the control device 80 returns to step S20. If all batteries are fully charged (YES in step S25), the control device 80 terminates the process.

[0050] Thus, in the injection molding machine system 100 of Modified Example 1, the DC power supply path is switched based on the State of Charge (SOC) of each battery 55A to 55D. In other words, in the injection molding machine system 100 of Modified Example 1, the DC / DC converter 31 performs the power supply processing to each battery 55A to 55D in a time-division manner. As a result, in the injection molding machine system 100 of Modified Example 1, there is no need to provide a DC / DC converter 31 for each of the five injection molding machines 50A to 50D, so power can be supplied by a single DC / DC converter 31, thereby reducing costs.

[0051] Furthermore, in the injection molding machine system 100 of Modified Example 1, in addition to the State of Charge (SOC), the decrease in SOC per unit time is used to supply power to batteries that reach the lower limit of the normal operating range earlier. As a result, in Modified Example 1, it is possible to prevent any of the batteries 55A to 55D from reaching the lower limit of the normal operating range.

[0052] <Modification 2> Embodiment 1 and Modification 1 describe an example in which the supply destination is determined based on information obtained from batteries 55A to 55D shown in Figure 1. However, the method for determining the supply destination is not limited to using only information about batteries 55A to 55D; the control device 80 may determine the supply destination based on information obtained from the injection molding machine 50. Modification 2 describes an example in which the supply destination is determined using the amount of SOC decrease per unit time in addition to comparing SOC. Figure 1 will also be referred to as appropriate in the following description of Modification 2. Furthermore, in Modification 2, the same configuration as in Embodiment 1 will not be repeated in the description.

[0053] Figure 6 is a flowchart showing the switching procedure of the switching device 41 in modified example 2. The control device 80 acquires the State of Charge (SOC) of each of the batteries 55A to 55D (step S30). Subsequently, the control device 80 in modified example 2 acquires the power consumption of each of the injection molding machines 50A to 50D (step S31). As described above, the power consumption of each of the injection molding machines 50A to 50D differs from that of the other depending on the shape and material of the molded product. Each of the injection molding machines 50A to 50D calculates the power consumption required for the injection molding process based on the set information. In step S31, the injection molding machines 50A to 50D transmit information indicating the power consumption to the control device 80.

[0054] The control device 80 compares the State of Charge (SOC) of each of the batteries 55A to 55D and the power consumption of each of the injection molding machines 50A to 50D (step S32). Based on the comparison results of SOC and power consumption, the control device 80 determines which battery 55 will be supplied, as the battery whose SOC falls below a predetermined reference value the earliest (step S33).

[0055] In the modified example 2, the control device 80 estimates the rate of SOC decrease per unit time based on the power consumption obtained from the injection molding machine 50. If the SOC continues to decrease at the estimated rate of decrease per unit time, the control device 80 calculates the period from the timing in step S33 until the SOC reaches the lower limit of the normal operating range. The control device 80 determines the battery 55 that will reach the lower limit of the normal operating range earliest as the supply destination.

[0056] The control device 80 switches the switching device 41 so that DC power is supplied to the battery 55 designated as the power supply destination (step S34). The control device 80 charges the battery 55 designated as the power supply destination in step S34 for a predetermined period of time (step S35). The control device 80 determines whether all of batteries 55A to 55D are fully charged (step S36). If not all batteries are fully charged (NO in step S36), the control device 80 returns to step S30. If all batteries are fully charged (YES in step S36), the control device 80 terminates the process.

[0057] Thus, in the injection molding machine system 100 of the modified example 2, the DC power supply path is switched based on the State of Charge (SOC) of each battery 55A to 55D. In other words, in the injection molding machine system 100 of the modified example 2, the DC / DC converter 31 performs the power supply processing to each battery 55A to 55D in a time-division manner. As a result, in the injection molding machine system 100 of the modified example 2, there is no need to provide a DC / DC converter 31 for each of the five injection molding machines 50A to 50D, so power can be supplied by a single DC / DC converter 31, thereby reducing costs.

[0058] Furthermore, in the injection molding machine system 100 of Modification 2, in addition to the SOC, the power consumption of the injection molding machine 50 is used to supply power to batteries that are expected to reach the lower limit of the normal operating range early. As a result, in Modification 2, it is possible to prevent any of the batteries 55A to 55D from reaching the lower limit of the normal operating range.

[0059] <Embodiment 2> Embodiment 1 described a configuration in which five injection molding machines 50A to 50D and batteries 55A to 55D are connected to one DC / DC converter 31. However, the number of DC / DC converters 31 included in the power supply unit 25 is not limited to one. Embodiment 2 describes a configuration of an injection molding machine system 100A that includes a DC / DC converter 32 in addition to the DC / DC converter 31. In Embodiment 2, the same configuration as in Embodiment 1 will not be repeated in the description.

[0060] Figure 7 is a schematic diagram of the configuration of the injection molding machine system 100A in Embodiment 2. As shown in Figure 7, the power supply unit 25 further comprises a DC / DC converter 32 in addition to the DC / DC converter 31. The DC / DC converter 32 has the same configuration as the DC / DC converter 31. That is, the DC / DC converter 32 converts the voltage of the DC power converted by the AC / DC converter 20. In addition, the power supply unit 25 further comprises a switching device 42 in addition to the switching device 41. The switching device 42 has the same configuration as the switching device 41. Note that the switching device 42 may correspond to the "second switching device" in this disclosure.

[0061] The DC / DC converter 32 is connected to the power line 35. The DC / DC converter 32 is equipped with batteries 55A to 55D via a switching device 42. The control device 80 controls the switching device 42 in addition to the switching device 41. In other words, in the second embodiment, each battery 55A to 55D is supplied with DC power from two supply paths via the switching devices 41 and 42.

[0062] As a result, in Embodiment 2, even if one of the DC / DC converters 31 and 32 fails, the other can be used to continue supplying power from the power supply unit 25 to each battery 55A to 55D. Similarly, in Embodiment 2, even if one of the switching devices 41 and 42 fails, the other can be used to continue supplying power from the power supply unit 25 to each battery 55A to 55D. In other words, the DC / DC converter 32 and the switching device 42 function as backups.

[0063] The method of switching the supply path by the switching device 42 may be different from the method of switching by the switching device 41. For example, in Embodiment 2, the control device 80 may switch the switching device 41 so that DC power is supplied to the battery 55 having the lowest SOC, and then switch the switching device 42 so that DC power is supplied to the battery 55 having the second lowest SOC.

[0064] Thus, in the injection molding machine system 100A of Embodiment 2, the control device 80 switches the DC power supply path based on the State of Charge (SOC) of each battery 55A to 55D. In other words, in the injection molding machine system 100A of Embodiment 2, the DC / DC converters 31 and 32 perform the power supply processing to each battery 55A to 55D in a time-division manner. As a result, in the injection molding machine system 100A of Embodiment 2, it is not necessary to provide DC / DC converters 31 and 32 for each of the five injection molding machines 50A to 50D, so power can be supplied by a single DC / DC converter 31, which reduces costs.

[0065] <Embodiment 3> Embodiment 1 described a configuration in which DC / DC converters 21 and 31 are electrically connected to a power line 35 supplied with DC power from an AC / DC converter 20. However, the configuration connected to the power line 35 is not limited to converters. Embodiment 3 describes a configuration of an injection molding machine system 100B in which a renewable energy power source is connected to the power line 35. In Embodiment 3, the same configuration as in Embodiment 1 will not be repeated in the description.

[0066] Figure 8 is a schematic diagram of the configuration of the injection molding machine system 100B in Embodiment 3. As shown in Figure 8, a renewable energy power source 91 is connected to the power line 35 as an external power source in addition to the grid power source 10. In the example in Figure 8, the renewable energy power source 91 is, for example, a solar power generation device. Note that the renewable energy power source 91 is not limited to a solar power generation device, but may be a wind power generation device, a hydroelectric power generation device, a geothermal power generation device, or a tidal power generation device.

[0067] The power conditioner 92 adjusts the power generated by the renewable energy source 91 and supplies DC power to the power line 35. The power conditioner 92 includes, for example, a DC / DC converter that converts the DC power generated by the solar cells into DC power that can be supplied to the power line 35.

[0068] As described above, in Embodiment 3, the renewable energy power source 91 is connected to the power line 35 through which DC power flows. This allows the injection molding machine system 100B to supply power to each battery 55A to 55D using the power generated by the renewable energy power source 91. In addition, in the example of Embodiment 3, DC power is generated by the renewable energy power source 91. The DC power generated by the renewable energy power source 91 is not converted to AC power before being supplied to each battery 55A to 55D, and the injection molding machine system 100B can suppress losses due to power conversion.

[0069] Furthermore, in the injection molding machine system 100B of Embodiment 3, the control device 80 switches the DC power supply path based on the State of Charge (SOC) of each battery 55A to 55D. In other words, in the injection molding machine system 100B of Embodiment 3, the DC / DC converters 31 and 32 perform the power supply processing to each battery 55A to 55D in a time-division manner. As a result, in the injection molding machine system 100B of Embodiment 3, it is not necessary to provide DC / DC converters 31 and 32 for each of the five injection molding machines 50A to 50D, so power can be supplied by a single DC / DC converter 31, which reduces costs.

[0070] [Note] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following embodiments.

[0071] (Section 1) An injection molding machine system 100 that drives multiple injection molding machines 50A to 50D using power received from a grid power supply 10. The injection molding machine system 100 comprises an injection molding machine 50A driven by a DC power supply, an injection molding machine 50B driven by a DC power supply, a battery 55A that supplies DC power to the injection molding machine 50A and is configured to store DC power, a battery 55B that supplies DC power to the injection molding machine 50B and is configured to store DC power, and a power supply device 25 that converts the power received from the grid power supply 10 and supplies the converted power to at least one of the batteries 55A and 55B. The power supply unit 25 includes an AC / DC converter 20 that converts AC power received from the grid power supply into DC power, a DC / DC converter 31 that converts the voltage of the DC power converted by the AC / DC converter 20, a switching device 41 configured to switch supply paths for supplying the DC power converted by the DC / DC converter 31 to at least one of batteries 55A and 55B, and a control device 80 that controls the switching device 41. The control device 80 switches the switching device 41 based on the respective SOC of batteries 55A and 55B.

[0072] According to the injection molding machine system 100 described in paragraph 1, in an injection molding machine system having a first injection molding machine and a second injection molding machine, there is no need to provide a DC / DC converter for each injection molding machine, so power can be supplied by a single DC / DC converter 31, and costs can be reduced.

[0073] (Section 2) In the injection molding machine system 100 according to Section 1, the control device 80 acquires the state of charge (SOC) of battery 55A and the state of charge (SOC) of battery 55B (Step S10), compares the SOC of battery 55A and the SOC of battery 55B (Step S11), switches the switching device 41 so that DC power is supplied to battery 55A if the SOC of battery 55A is lower than the SOC of battery 55B, and switches the switching device 41 so that DC power is supplied to battery 55B if the SOC of battery 55B is lower than the SOC of battery 55A (Step S13).

[0074] According to the injection molding machine system 100 described in paragraph 2, DC power can be supplied to the battery having the lowest SOC.

[0075] (3) In the injection molding machine system according to paragraph 1, the control device 80 acquires the SOC of battery 55A and the SOC of battery 55B (step S20), compares the amount of decrease in the SOC of battery 55A per unit time and the amount of decrease in the SOC of battery 55B per unit time (step S21), determines which of batteries 55A and 55B will fall below a predetermined reference value earlier (step S22), and switches the switching device 41 so that DC power is supplied to the battery 55 that will fall below the predetermined reference value earlier (step S23).

[0076] According to the injection molding machine system 100 described in paragraph 3, DC power can be supplied to a battery whose SOC falls below a predetermined reference value early on, based on the rate of decrease in SOC per unit time.

[0077] (Paragraph 4) In the injection molding machine system 100 relating to Paragraph 1, the control device 80 acquires the SOC of battery 55A and the SOC of battery 55B (step S30), acquires the power consumption of injection molding machine 50A and the power consumption of injection molding machine 50B (step S31), compares the SOC of battery 55A and the SOC of battery 55B and compares the power consumption of injection molding machine 50A and the power consumption of injection molding machine 50B (step S32), determines which of batteries 55A and 55B will have an SOC that falls below a predetermined reference value early on (step S33), and switches the switching device 41 so that DC power is supplied to the battery that will have an SOC that falls below a predetermined reference value early on (step S34).

[0078] According to the injection molding machine system 100 described in paragraph 4, DC power can be supplied to a battery having a State of Charge (SOC) that falls below a predetermined standard value early on, based on the power consumption of the injection molding machine 50.

[0079] (Article 5) In the injection molding machine system 100 relating to any one of Articles 1 to 4, the DC / DC converter 31 is an isolated DC / DC converter.

[0080] According to the injection molding machine system 100 described in paragraph 5, the primary and secondary sides of the DC / DC converter 31 can be isolated, and even if a ground fault occurs on the injection molding machine 50 side, the ground fault will not affect the secondary side of the DC / DC converter 31.

[0081] (Clause 6) In an injection molding machine system 100 relating to any one of paragraphs 1 to 5, the power supply unit 25 further includes a DC / DC converter 32 in addition to the DC / DC converter 31, which converts the voltage of the DC power converted by the AC / DC converter 21.

[0082] According to the injection molding machine system 100A described in paragraph 6, even if one of the DC / DC converters 31 or 32 fails, the other can be used to continue supplying power from the power supply unit 25 to each battery 55A to 55D.

[0083] (Clause 7) In an injection molding machine system relating to any one of paragraphs 1 to 6, the power supply unit (25) receives power generated by a renewable energy source (91).

[0084] According to the injection molding machine system 100B described in paragraph 7, power can be supplied to each battery 55A to 55D using electricity generated by the renewable energy power source 91. [Explanation of Symbols]

[0085] 10 power supply systems, 11 beds, 12 fixed panels, 13 clamping housings, 14 movable panels 15 Tie bar, 16 Clamping mechanism, 17,18 Mold, 20 AC / DC converter, 21,31,32 DC / DC converter, 22,55,55A~55D Battery, 23 Screw, 24 Drive mechanism, 25 Power supply, 26 Injection nozzle, 27 Nozzle touch device, 30 Display device, 30B Input device, 30D Display, 35 Power line, 41,42 Switching device, 44 Memory unit, 50,50A~55D Injection molding machine, 51 Ball screw, 52 Circuit board, 52i Input interface, 52o Output interface, 53a,53b Servo amplifier, 57 Control unit, 57b Memory, 60 Clamping device, 61 Injection device, 62 Base, 63 Heating cylinder, 64 Hopper, 65 Thermocouple, 40,80 Control device, 90 Storage device, 91 Renewable energy power supply, 92 power conditioner, 100, 100A, 100B injection molding machine system.

Claims

1. An injection molding machine system that drives multiple injection molding machines using power received from the grid power supply, A first injection molding machine driven by a DC power supply, A second injection molding machine driven by a DC power supply, A first energy storage device configured to supply DC power to the first injection molding machine and to store DC power, A second energy storage device is configured to supply DC power to the second injection molding machine and to store DC power, The system includes a power supply device that converts power received from the grid power supply and supplies the converted power to at least one of the first energy storage device and the second energy storage device, The aforementioned power supply device is A first power converter that converts AC power received from the aforementioned grid power supply into DC power, A second power converter that converts the DC power converted by the first power converter into a voltage, A first switching device configured to switch supply paths for supplying DC power converted by the second power converter to at least one of the first and second energy storage devices, Includes a control device for controlling the first switching device, The control device controls the State of Control (SOC) of each of the first and second energy storage devices. An injection molding machine system that switches the first switching device based on the Charge.

2. The control device is The first SOC of the first energy storage device and the second SOC of the second energy storage device are obtained. When the first SOC is below the second SOC, the first switching device is switched so that DC power is supplied to the first energy storage device. The injection molding machine system according to claim 1, wherein the first switching device is switched so that DC power is supplied to the second energy storage device when the second SOC is lower than the first SOC.

3. The control device is The first SOC of the first energy storage device and the second SOC of the second energy storage device are obtained. The first decrease per unit time of the first SOC and the second decrease per unit time of the second SOC are compared, Of the first and second energy storage devices, the energy storage device whose SOC falls below a predetermined standard value early on is determined. The injection molding machine system according to claim 1, wherein the first switching device is switched so that DC power is supplied to the energy storage device that falls below a predetermined standard value at an early stage.

4. The control device is The first SOC of the first energy storage device and the second SOC of the second energy storage device are obtained. The first power consumption of the first injection molding machine and the second power consumption of the second injection molding machine are obtained. A comparison is made between the first SOC and the second SOC, and between the first power consumption and the second power consumption. Of the first and second energy storage devices, the energy storage device whose SOC falls below a predetermined standard value early on is determined. The injection molding machine system according to claim 1, wherein the first switching device is switched so that DC power is supplied to the energy storage device that falls below a predetermined standard value at an early stage.

5. The injection molding machine system according to any one of claims 1 to 4, wherein the second power converter is an isolated DC / DC converter.

6. The aforementioned power supply device is In addition to the second power converter, a third power converter is provided that performs voltage conversion on the DC power converted by the first power converter, The present invention further includes a second switching device configured to switch supply paths for supplying DC power converted by the third power converter to at least one of the first and second energy storage devices, The injection molding machine system according to any one of claims 1 to 4, wherein the control device switches the second switching device based on the SOC of the first and second energy storage devices, respectively.

7. The injection molding machine system according to any one of claims 1 to 4, wherein the power supply device receives electricity generated by a renewable energy source.

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