Injection molding machine and method for predicting the life of injection molding machine parts

Abstract

To provide an injection molding machine that can predict a life of components included in the injection molding machine with a simple configuration.SOLUTION: An injection molding machine is equipped with electrical components (SW1-SWn) configured to turn power on and off, and a control device 40 that controls the electrical components. The control device 40 includes a memory part 44 that stores a size of a load connected to the electric components (SW1-SWn), and an operation part 41 that predicts a life of the electric components (SW1-SWn) based on the size of the load stored in the memory part 44 and a number of times the electric components have performed on / off operations.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an injection molding machine and a method for predicting the life of an injection molding machine component. [Background technology]

[0002] In injection molding machines and other molding machines used in factories, machine troubles can occur due to part failure. In order to prevent such machine troubles, it is necessary to manage the parts by replacing them at the appropriate time.

[0003] Japanese Patent Laid-Open Publication No. 2017-087587 (Patent Document 1) discloses an information management device for injection molding that manages information on parts used in injection molding. This device calculates the total value of the product of the value of a physical quantity that represents the load applied to the part in one shot and the number of shots at that value since the start of use of the part, and detects the degree of deterioration of the part. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-087587 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the injection molding machine of Patent Document 1 requires sensors to detect physical quantities used to calculate the degree of deterioration of parts. If such sensors are installed in various locations, the manufacturing cost of the injection molding machine increases.

[0006] The present disclosure has been made to solve such problems, and its purpose is to provide an injection molding machine that can predict the lifespan of parts included in the injection molding machine with a simple configuration. [Means for solving the problem]

[0007] According to one embodiment, an injection molding machine includes an electric component configured to switch between a conductive state and a non-conductive state, and a control device that controls the electric component. The control device includes a memory unit that stores a magnitude of a load connected to the electric component, and a calculation unit that predicts a life of the electric component based on the magnitude of the load stored in the memory unit and the number of operations in which the electric component transitions between a conductive state and a non-conductive state. Effect of the Invention

[0008] According to the injection molding machine of the present disclosure, it is possible to predict the lifespan of parts included in the injection molding machine while suppressing an increase in manufacturing costs. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is an external view of an injection molding machine 100. [Diagram 2] FIG. 1 is a schematic block diagram of an injection molding machine 100. [Diagram 3] 1 is a diagram showing an example of an external device 101 and an example of a connection form. [Figure 4] FIG. 1 is a circuit diagram showing the configuration of a connection portion between an IO board and a PLC. [Diagram 5] FIG. 13 is a diagram for explaining how the magnitude of a load corresponding to each switch element is registered; [Figure 6] 10 is a flowchart for explaining control of a load registration process. [Figure 7] 11 is a flowchart for explaining a life prediction process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0011] <Injection molding machine> In the following, an injection molding machine 100 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is an external view of the injection molding machine 100. The injection molding machine 100 includes a clamping device 10 that clamps a mold, an injection device 20 that melts and injects an injection material, a display device 30, and a control device 40.

[0012] The injection molding machine 100 is placed on an XY plane. The direction perpendicular to the XY plane is the Z-axis direction. The positive direction of the Z-axis in Fig. 1 may be referred to as the upper side or upward, and the negative direction as the lower side or downward.

[0013] <Mold clamping device> The mold clamping device 10 includes a bed 11, a fixed platen 12, a mold clamping housing 13, a movable platen 14, tie bars 15, a mold clamping mechanism 16, molds 17 and 18, and a ball screw 51. The bed 11 supports components of the mold clamping device 10, such as the fixed platen 12, the mold clamping housing 13, and the movable platen 14. The fixed platen 12 is fixed to the bed 11. The mold clamping housing 13 is configured to be slidable in the X-axis direction on the bed 11. Similarly, the movable platen 14 is configured to be slidable in the X-axis direction on the bed 11.

[0014] The tie bar 15 is disposed between the fixed platen 12 and the clamping housing 13, and connects the fixed platen 12 and the clamping housing 13. The tie bar 15 includes a plurality of bars. The injection molding machine 100 shown in Fig. 1 is provided with the tie bar 15 including four bars. Note that the tie bar 15 may include five or more bars.

[0015] The movable platen 14 is configured to be slidable 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. The clamping housing 13 in the first embodiment is configured to include a toggle mechanism. The clamping mechanism 16 may be configured to include a direct pressure type clamping mechanism. The direct pressure type clamping mechanism refers to a clamping cylinder.

[0016] The molds 17 and 18 are provided between the fixed platen 12 and the movable platen 14. The molds 17 and 18 are configured to be opened and closed by a mold clamping mechanism 16. The ball screw 51 converts the rotational motion of the motor 50 into linear motion to open and close the mold clamping mechanism 16.

[0017] <Injection device> The injection device 20 includes a base 21, a heating cylinder 22, a screw 23, a driving mechanism 24, a hopper 25, an injection nozzle 26, a nozzle touch device 27, and a sensor 55. The base 21 is disposed on the positive side of the X-axis of the bed 11, and supports the driving mechanism 24 and the like. The screw 23 is disposed inside the heating cylinder 22. The driving mechanism 24 rotates the screw 23 about the X-axis direction as its central axis, and drives the screw 23 itself to slide in the X-axis direction.

[0018] The hopper 25 is provided on the positive side of the Z axis of the heating cylinder 22. The injection nozzle 26 is provided at the end of the heating cylinder 22 on the negative side of the X axis. The nozzle touch device 27 slides the injection device 20 in the X axis direction to bring the injection nozzle 26 into contact with the sprue bush of the mold 18. In one example, the sensor 55 is a thermocouple disposed near the injection nozzle 26. The thermocouple is a temperature sensor that detects the temperature at the location where it is disposed. The sensor 55 may be a temperature sensor other than a thermocouple.

[0019] The base 21 includes therein a control device 40, a servo amplifier 53, a cooling fan 54, and a relay 56. The control device 40 includes a control board 52 equipped with a CPU, a memory, and the like. The control device 40 acquires detection values ​​of various sensors 55 including thermocouples and the like, and performs overall control of the injection molding machine 100. The detection values ​​of the various sensors include, for example, temperature information of the heating cylinder 22, or position information of various movable parts such as the mold clamping mechanism 16, molds 17 and 18, and injection nozzle 26.

[0020] The servo amplifiers 53 supply three-phase AC power to the corresponding motors. The cooling fans 54 blow or exhaust air to prevent the heat-generating components arranged inside the base 21 from overheating. The relays 56 are, for example, thermal relays or current relays for preventing overload of the motors. The relays 56 may be relays used for purposes other than preventing overload of the motors.

[0021] The display device 30 is provided on the negative side of the Y axis of the injection molding machine 100. The display device 30 includes a display 31 and an input device 32. The input device 32 includes, for example, a plurality of buttons. In one aspect, the display device 30 may include a plurality of displays and speakers, etc. The display 31 and the input device 32 may be integrally provided as a touch panel. Note that, although an example of a horizontal injection molding machine has been described in FIG. 1, the injection molding machine 100 of the first embodiment is not limited thereto, and may be a vertical injection molding machine.

[0022] The injection molding machine 100 is configured to allow a user to connect various externally connected devices 101 according to the type of molded product. The injection molding machine 100 further includes an input / output board (hereinafter referred to as an IO (Input-Output) board) 45 for connecting the externally connected device 101. The IO board 45 is configured to drive the externally connected device 101 upon receiving a command from the control device 40.

[0023] <Block diagram of injection molding machine> 2 is a schematic block diagram of the injection molding machine 100. The control device 40 includes a storage unit 44 and a control board 52. The storage unit 44 may include, for example, a hard disk drive (HDD) or a flash solid state drive (SSD). The control board 52 is equipped with a calculation unit 41, an input interface 42, and an output interface 43. The calculation unit 41 includes a CPU 41a and a memory 41b.

[0024] The memory 41b includes a read only memory (ROM) and a random access memory (RAM), and stores programs executed by the CPU 41a, etc. The CPU 41a loads the programs stored in the ROM into the RAM and executes them.

[0025] The calculation unit 41 may be configured with a dedicated hardware circuit. That is, the calculation unit 41 may be realized by an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), etc. The calculation unit 41 may also be realized by appropriately combining a processor, a memory, an ASIC, an FPGA, etc.

[0026] The calculation unit 41 receives detection values ​​from various sensors 55 such as thermocouples via the input interface 42. The calculation unit 41 transmits control commands to the drive mechanism 24, the display device 30, and the IO board 45 via the output interface 43. The calculation unit 41 drives the drive mechanism 24 using the detection values ​​of the various sensors. The calculation unit 41 displays the state of the injection molding machine 100 on the display device 30 based on the detection values ​​of the various sensors. The calculation unit 41 controls the externally connected machine 101 connected to the IO board 45 based on the detection values ​​of the various sensors.

[0027] 3 is a diagram showing an example of an external connection device 101 and an example of a connection form. The external connection device 101 includes a removal device 103 that removes a molded product from a mold after injection molding, and a PLC (Programmable Logic Controller) 102 that connects the removal device 103 to an IO board 45 of the injection molding machine.

[0028] The control device 40 sends a control signal to the PLC 102 from a terminal of the IO board 45. Upon receiving the control signal from the IO board 45, the PLC 102 drives various drive parts (arm, chuck, etc.) of the extractor 103.

[0029] Fig. 4 is a circuit diagram showing the configuration of the connection between the IO board and the PLC. The PLC 102 has an input terminal that is electrically insulated from the internal circuit 110, and signals are transmitted by a photocoupler. There are various specifications for the input terminal of the PLC 102, but Fig. 4 shows an example of a negative common type (sink type) for DC input. Note that the input terminal of the PLC 102 may also be, for example, a positive common type (source type) for DC input.

[0030] The IO board 45 includes a power supply VD, terminals TG, T1 to Tn, and NC1 to NCm, and switch elements SW1 to SWn and SF1 to SFm.

[0031] The terminal TG is connected to a common ground which is a reference potential of the power supply VD of the IO substrate 45. Each of the switch elements SW1 to SWn is connected between a corresponding one of the terminals T1 to Tn and the positive terminal of the power supply VD. Each of the switch elements SF1 to SFm is connected between a corresponding one of the terminals NC1 to NCm and the positive terminal of the power supply VD. The switch elements are elements which can switch between conductive and non-conductive states of power, and are formed of relays, transistors, or the like.

[0032] The terminal TG is connected to a corresponding negative common terminal of the PLC 102. The terminals T1 to Tn are connected to corresponding input terminals of the PLC 102. The terminals NC1 to NCm are unused remaining terminals.

[0033] Note that the examples shown in Figures 3 and 4 are just examples. When the removal arm, removal chuck, etc. of the removal machine 103 are connected, the PLC 102 is often used for the external connection that is directly connected to the substrate. However, when an air jet is connected, a solenoid valve may be directly operated instead of the PLC 102.

[0034] <Load registration process> 5 is a diagram for explaining the state of registration of the magnitude of the load corresponding to each switch element. The magnitude of the load corresponding to each switch element is registered in the storage unit 44 of the control device 40, for example, as shown in FIG.

[0035] Regarding the registration of the load size, the following three cases 1) to 3) are possible. 1) When the external connection device of a certain electrical component is preset in advance. 2) When automatically recognizing the connected load. 3) Obtaining load information from users.

[0036] Regarding 1), for example, there is a case where it is decided which external connection machine is connected to the connection terminal of a certain electric component, and the load of the connected external connection machine is stored in advance. Whether or not to use an external connection machine connectable to the connection terminal of a certain electric component varies from user to user. For example, if the external connection machine connectable to the connection terminal of a certain electric component is a take-out machine, nothing will be connected to the connection terminal in the injection molding machine of a user who does not use a take-out machine. Therefore, the control device 40 judges whether or not an external connection machine connectable to each connection terminal is connected, and stores the magnitude of the load that is stored in advance for the switch element corresponding to that terminal.

[0037] Concerning 2), specifically, a method of determining by communication is conceivable. For example, when a take-out machine having a communication function is connected to an injection molding machine, a method is conceivable in which the model of the take-out machine is determined by communication and the load of the I / O port connected to the take-out machine of the corresponding model is stored in advance in the memory unit of the injection molding machine. In other words, the control device 40 determines what the connected externally connected machine is, and determines the load of the connected externally connected machine from table data that corresponds the externally connected machines and the loads of the I / O ports stored in the memory unit 44. In this way, even if there are multiple candidates for the externally connected machines to be connected to the connection terminal of a certain electric component, the user does not need to input anything.

[0038] As for 3), specifically, the user uses the input device 32 to select which external device is connected to the connection terminal of a certain electric component from a list of external devices displayed on the display 31. Table data associating the external device with the magnitude of the load on the I / O port is pre-stored in the storage unit 44. When the user selects an external device from the list of potential connection destinations for electric components, the control device 40 identifies the magnitude of the load on the I / O port from the table data. In this example, the information on the load that the control device 40 acquires from the user is information on the external device selected from the list. The user may also input the magnitude of the load as the information on the load.

[0039] In the example shown in Fig. 4, the magnitude of the load specified based on the information on the load acquired from the user is registered for each switch element of the IO board 45 as shown in Fig. 5. The external connection device 101 can be other than the unloader, and even if it is a unloader, the load differs depending on whether the relay device is a PLC or a solenoid valve. However, the elements connected to each switch element of the IO board 45 are devices specific to injection molding machines such as unloaders, and it is possible to prepare a list of candidates based on some assumptions. Therefore, the load can be specified in a simple manner without detecting the load with a sensor such as a current sensor.

[0040] The load size can be classified into three categories, for example: large, medium, and small. The classification can be determined as follows according to the rated current of the connected device. Large: 400mA or more Medium: 100mA or more and less than 400mA Small: Less than 100mA For example, the load category for a PLC and a relay with a small current capacity is "small." The load category for a relay with a large current capacity and a solenoid valve with a small control flow rate is "medium." The load category for a solenoid valve with a large control flow rate is "large." These categories can be determined by the rated current of the connected load. The number of categories may be two, four or more.

[0041] 5 is a field that displays the results of a life prediction process that will be described later. The degree of wear will be described later using an equation.

[0042] 6 is a flowchart for explaining the control of the load registration process. First, in step S1, the calculation unit 41 judges whether or not there is an update to the load registration. For example, it is judged that there is an update to the load registration when the externally connected device 101 is changed in accordance with a change in the type of molded product. In step S1, the calculation unit 41 may automatically detect the change in connection, or may detect that the user has operated a button or the like that notifies the load connection change. If there is no update (NO in S1), the registration process in step S2 is not performed.

[0043] If there is an update to the load registration (YES in S1), the calculation unit 41 updates the database showing the correspondence between the switch elements and the load magnitudes as shown in FIG. 5 based on automatic detection of a connection change, data communication from the external connection device 101, or information about the load input by the user, and the processing of step S2 is completed.

[0044] <Lifespan prediction processing> FIG. 7 is a flow chart for explaining the process of life prediction. In step S11, the calculation unit 41 counts the number of switch operations. The calculation unit 41 appropriately switches the switch elements SW1 to SWn of the IO board between on and off in order to operate an externally connected device such as an extractor. For this reason, the calculation unit 41 increments the number of switch operations corresponding to each switch element by 1 each time the switch element is turned on or off, that is, each time the switch element is transitioned between a conductive state and a non-conductive state. For example, if the switch element is a relay, a minute spark occurs when a current starts to flow when the switch is turned on, and when the current is interrupted when the switch is turned off, shortening the life of the switch element.

[0045] Even in the case of a take-out machine, the number of times that the switch elements SW1 to SWn switch between the on and off states per shot for molding a molded product depends on the type of mechanism used, such as the take-out arm and take-out chuck, which are the loads connected, and the type of actuator, and may not be uniform. For this reason, it is not accurate to manage the lifespan by the number of shots. In this embodiment, the number of switch operations is counted to calculate the lifespan, so that an accurate lifespan can be calculated for each of the switch elements SW1 to SWn.

[0046] Next, in step S12, the calculation unit 41 accumulates the load by accumulating the number of times each of the switching elements SW1 to SWn has been operated in the storage unit 44 or the memory 41b.

[0047] Furthermore, in step S13, the calculation unit 41 calculates the life span. If the load is classified into three patterns, large / medium / small, the degree of wear indicating the life span can be calculated for each switch element, for example, by the following formula.

[0048] Wear degree=NL / JNL+NM / JNM+NS / JNS Here, NL indicates the number of switch operations when the load category is "large," and JNL indicates the number of lifetimes when a load of "large" load category is connected to the switch element. NM indicates the number of switch operations when the load category is "medium," and JNM indicates the number of lifetimes when a load of "medium" load category is connected to the switch element. NS indicates the number of switch operations when the load category is "small," and JNS indicates the number of lifetimes when a load of "small" load category is connected to the switch element. The lifetimes JNL, JNM, and JNS corresponding to each of the three categories can be determined based on the data sheet of the switch element component, etc.

[0049] For example, if a load with a "large" load category is connected to switch element SW1 and there is no change in the connection, when NL=JNL, the wear degree becomes 1 and it is determined that the life has been reached. However, there may be a change in the connection of an externally connected device, and the connection may change from a "large" load category to a "medium" load category. In such a case, the wear degree is not reset and continues to accumulate even if the connection of the externally connected device is changed.

[0050] For example, suppose a load in the "large" category is first connected, and the wear level increases to NL / JNL = 0.5. If the load is then changed to a "medium" category load, the wear level = 0.5 is maintained, and as the number of switch operations increases, NM / JNM increases from zero, the wear level increases. Then, when NM / JNM = 0.5, the integrated wear level will total 1, and it is determined that the switch element has reached the end of its life. The same can be considered when the load is changed to a "small" category load, etc.

[0051] As described above, the lifetime of the switching element in step S13 can be correctly predicted by carrying over the degree of wear even if the load connection is changed during the process.

[0052] Then, in step S14, the lifespan is notified, for example, a numerical value of the degree of wear indicating the lifespan is displayed on display 31. The degrees of wear may be displayed in a list for all switch elements mounted on IO board 45, or the switch element showing the largest numerical value of the degree of wear may be displayed as a representative value indicating the lifespan of IO board 45 in order to encourage replacement of IO board 45.

[0053] In the above explanation, the degree of wear is shown as 1, which means the end of the life, but it may be displayed as a percentage (%). An example of percentage display is shown in the right column of Fig. 6. When displaying the degree of wear numerically, weight coefficients KL, KM, and KS may be multiplied by each term as shown in the following formula. Degree of wear = KL x NL / JNL + KM x NM / JNM + KS x NS / JNS Also, in step S14, when the degree of wear reaches a judgment threshold (for example, 0.9 or 90%), a message may be displayed on display 31 to advise replacing IO board 45. However, there are cases where replacing IO board 45 is not economical. When there are unused terminals NC1 to NCm as shown in Fig. 4 and the number of switch elements whose degree of wear approaches the judgment threshold is m or less, in step S14, a message may be displayed on display 31 to the effect that continued use is possible if the connection is changed.

[0054] In the present embodiment described above, a switch element mounted on an IO board has been described as an example of an electrical component configured to switch between conductive and non-conductive states of power. However, the electrical component whose life span is predicted may be a relay, a transistor, an inverter, or the like configured to switch between conductive and non-conductive states of power.

[0055] (summary) Finally, the present embodiment will be summarized with reference to the drawings again. As shown in Fig. 2, an injection molding machine 100 of the present embodiment includes electric components (SW1 to SWn) configured to switch between conductive and non-conductive states of power, and a control device 40 that controls the electric components. The control device 40 includes a storage unit 44 that stores the magnitude of the load connected to the electric components (SW1 to SWn), and a calculation unit 41 that predicts the life of the electric components based on the magnitude of the load stored in the storage unit 44 and the number of operations in which the electric components have transitioned between a conductive state and a non-conductive state.

[0056] In this way, the control device predicts the lifespan based on the number of operations of the electrical components that can be counted when controlling them and the stored load, so there is no need for a sensor to measure the magnitude of the load, making it possible to predict the lifespan with a simple configuration.

[0057] Preferably, the storage unit 44 stores in advance a plurality of life times JNL, JNM, JNS corresponding to a plurality of load size categories "large", "medium", and "small", respectively. For example, as described in FIG. 6, the calculation unit 41 acquires information on the load connected to the electric components (SW1 to SWn) from a user or automatically detects the load, and stores the load size in the storage unit 44. Then, as shown in FIG. 7, the calculation unit 41 predicts the life of the electric components (SW1 to SWn) based on the degree of wear, which is the ratio of the number of operations to the number of life times corresponding to the load size stored in the storage unit 44 among the plurality of life times.

[0058] More preferably, the injection molding machine 100 further includes an input / output board 45 to which the user connects the externally connected device 101. As shown in the example of FIG. 4, the electric components (SW1 to SWn) are switch elements SW1 to SWn mounted on the input / output board 45. As shown in FIG. 6, when the user changes the externally connected device 101 (YES in S1), the calculation unit 41 updates the magnitude of the load stored in the storage unit 44 (S2). For example, the calculation unit 41 reacquires information on the load of the externally connected device 101 connected to the switch elements SW1 to SWn from the user and stores the magnitude of the load in the storage unit 44. The calculation unit 41 integrates the degree of wear calculated before the user changes the externally connected device 101 by the degree of wear corresponding to the magnitude of the load registered after the user changes the externally connected device 101.

[0059] With this configuration, the degree of deterioration of the switch element is accumulated, so that even if the external device 101 is changed midway, the life can be predicted correctly.

[0060] In another aspect, more preferably, the injection molding machine 100 further includes an input / output board 45 to which a user connects the external connection device 101. The electric components are first switch elements SW1-SWn mounted on the input / output board 45. As shown in FIG. 4, the injection molding machine 100 further includes second switch elements SF1-SFm mounted on the input / output board 45. When the second switch elements SF1-SFm are unused and the wear degree corresponding to the second switch elements SF1-SFm is lower than the wear degree corresponding to the first switch elements SW1-SWn, the calculation unit 41 performs the following notification. That is, the calculation unit 41 notifies the user that the second switch elements SF1-SFm can be used instead of the first switch elements SW1-SWn.

[0061] With this configuration, when it is not economical to replace the input / output board 45, it is possible to continue using the input / output board 45, thereby extending the life of the parts.

[0062] In another aspect, the present embodiment relates to a method for predicting a life span of a component of an injection molding machine 100. The method for predicting a life span includes a step (FIG. 6: S2) of storing the magnitude of a load connected to an electric component (SW1 to SWn) configured to switch between conductive and non-conductive states. The method for predicting a life span of the electric component based on the stored magnitude of the load and the number of operations in which the electric component transitions between a conductive state and a non-conductive state (FIG. 7: S11 to S13). [Explanation of symbols]

[0063] 10 mold clamping device, 11 bed, 12 fixed platen, 13 mold clamping housing, 14 movable platen, 15 tie bar, 16 mold clamping mechanism, 17, 18 mold, 20 injection device, 21 base, 22 heating cylinder, 23 screw, 24 drive mechanism, 25 hopper, 26 injection nozzle, 27 nozzle touch device, 30 display device, 31 display, 32 input device, 40 control device, 41 calculation unit, 41a CPU, 41b memory, 42 input interface, 43 output interface, 44 memory unit, 45 input / output board, 50 motor, 51 ball screw, 52 control board, 53 servo amplifier, 54 cooling fan, 55 sensor, 56 relay, 100 injection molding machine, 101 external connection machine, 103 removal machine, 110 Internal circuit, NC1 to NCm, T1 to Tn, TG terminals, SF1 to SFm, SW1 to SWn switch elements, VD power supply.

Claims

1. an electrical component configured to switch between conducting and not conducting electrical power; a control device that controls the electrical components; The control device includes: A storage unit that stores the magnitude of a load connected to the electrical component; a calculation unit that predicts a life of the electrical component based on the magnitude of the load stored in the storage unit and the number of operations in which the electrical component transitions between a conductive state and a non-conductive state, the storage unit stores in advance a plurality of life times corresponding to a plurality of categories of the magnitude of the load, The calculation unit predicts the life of the electrical component based on a degree of wear, which is a ratio of the number of operations to a life number corresponding to a magnitude of the load stored in the memory unit among the multiple life numbers.

2. Further, an input / output board to which a user connects an external device is provided, the electrical component is a switch element mounted on the input / output board, The calculation unit updates the magnitude of the load stored in the storage unit when the user changes the external device, 2. The injection molding machine according to claim 1, wherein the calculation unit multiplies the degree of wear calculated before the user changes the externally connected device by the degree of wear corresponding to the magnitude of the load registered after the user changes the externally connected device.

3. The injection molding machine includes: Further, an input / output board to which a user connects an external device is provided, the electrical component is a first switch element mounted on the input / output board, The injection molding machine includes: A second switch element mounted on the input / output board, 2. The injection molding machine according to claim 1, wherein, when the second switch element is unused and a degree of wear corresponding to the second switch element is lower than a degree of wear corresponding to the first switch element, the calculation unit notifies a user that the second switch element can be used instead of the first switch element.

4. A method for predicting the life of a part of an injection molding machine, comprising: (a) storing a magnitude of a load connected to an electrical component configured to switch between conducting and non-conducting electrical power; and (b) predicting a life of the electrical component based on the stored magnitude of the load and the number of operations in which the electrical component transitions between a conductive state and a non-conductive state; A plurality of life cycles are predefined corresponding to a plurality of load magnitude categories, A life prediction method, comprising: a step of predicting a life of the electrical component based on a degree of wear, which is a ratio of the number of operations to a life number corresponding to the stored magnitude of the load among the plurality of life numbers.

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