Heating device, heating control method, and heating control program

Abstract

To provide a heating device, a heating control method, and a heating control program, capable of drying a moisture-absorbed heater in a short time.SOLUTION: A heating device includes: one or plural heater circuit units; a power supply unit that supplies electricity to the heater circuit unit; a main breaker electrically connected between the heater circuit unit and the power supply unit; and a control unit that controls the heater circuit unit. The heater circuit unit includes a heater that heats a barrel of an injection molder and a solid-state relay that turns on and off power supply to the heater. The main breaker includes an electrical leak detector capable of detecting an electrical leak in the heater circuit unit and is configured to be activated when a predetermined electrical leak detection time has elapsed since the electrical leak detector detects the electrical leak. The control unit is configured capable of executing main breaker activation evading control that controls the solid-state relay to turn off the power supply temporarily before the electrical leak detection time elapses.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heating device, a heating control method, and a heating control program. [Background technology]

[0002] Conventionally, injection molding machines may be stopped for long periods of time due to factory operation. In such cases, condensation may occur around the heater due to the influence of the outside air. If voltage is applied to the heater while it is still condensed, electricity will leak from the heater that has absorbed moisture. If this is detected by the leakage detector, the breaker will trip and cut off the power supply. Therefore, if the heater condenses, it is necessary to dry the heater that has absorbed moisture.

[0003] In order to dry the heaters, for example, it is necessary to remove all the heaters from the injection molding machine and dry them in a hot air oven. Also, in order to eliminate the process of removing the heaters from the injection molding machine, there is a heating control device for an injection molding machine that is provided with, for example, a leakage detector that detects leakage current from a heater covered with an insulating material and outputs a signal inversely proportional to the magnitude of the leakage current, and a voltage regulator that adjusts the voltage of the heater in response to the signal from the leakage detector, making it possible to dehumidify the insulating material of the insulated heater by heating it with the heater (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 1-176539 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional heating control devices dehumidify by applying a lower voltage to the heater than normal, so the amount of heat generated by the heater is small, and it takes a long time for the heater to dry due to the heat generated by the heater.

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a heating device, a heating control method, and a heating control program capable of drying a heater that has absorbed moisture in a short period of time. [Means for solving the problem]

[0007] The heating device of the present invention comprises one or more heater circuit units, a power supply unit that supplies power to the heater circuit unit, a main breaker electrically connected between the heater circuit unit and the power supply unit, and a control unit that controls the heater circuit unit, wherein the heater circuit unit includes a heater that heats a barrel of an injection molding machine and a solid state relay that turns on / off the power supply to the heater, the main breaker includes a leakage current detector that can detect a leakage current in the heater circuit unit and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detected the leakage current, and the control unit is configured to be capable of executing main breaker operation avoidance control that controls the solid state relay to temporarily turn off the power supply before the leakage current detection time has elapsed.

[0008] In the heating device according to the present invention, the control unit may control the solid-state relay to repeatedly turn off the power supply at a period shorter than the leakage current detection time during the main breaker operation avoidance control.

[0009] In the heating device of the present invention, the heater circuit unit includes a temperature sensor, and the control unit is configured to be able to acquire an actual temperature value of the temperature sensor and to be able to proportionally control the solid-state relay so that the actual temperature value approaches a temperature set value, and a control period of the solid-state relay in the proportional control may be set to be equal to or shorter than the leakage current detection time.

[0010] In the heating device according to the present invention, the heater circuit section includes a temperature sensor, and the control section may be configured to be able to execute a temperature acquisition process to acquire an actual temperature value of the temperature sensor, a normal control switching temperature determination process to determine whether the actual temperature value is equal to or higher than a predetermined normal control switching temperature, a control switching process to switch control of the heater circuit section to normal control if the actual temperature value is equal to or higher than the normal control switching temperature, and a control continuation process to continue the main breaker operation avoidance control if the actual temperature value is less than the normal control switching temperature.

[0011] In the heating device of the present invention, the control unit may be configured to execute a leakage current determination process for determining whether or not the leakage current detector has detected the leakage current after a control switching process, an abnormality determination process for determining that the leakage current is an abnormality caused by insulation deterioration of the heater when it is determined that the leakage current has been detected, and a warning process for warning a user of the abnormality.

[0012] In the heating device of the present invention, the control unit may be configured to be able to execute, after the abnormality determination process, an emergency control process for switching control of the heater circuit unit to the main breaker operation avoidance control, a normal control target temperature determination process for determining whether the actual temperature measurement value is equal to or higher than a predetermined normal control target temperature which is higher than the normal control switching temperature, an emergency control termination process for switching control of the heater circuit unit back to normal control if the actual temperature measurement value is equal to or higher than the normal control target temperature, and an emergency control continuation process for continuing the main breaker operation avoidance control if the actual temperature measurement value is lower than the normal control target temperature.

[0013] In the heating device of the present invention, each heater circuit unit includes an individual breaker, the individual breaker has a leakage current detection function and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detection is detected, and the control unit may be configured to be capable of executing individual breaker operation avoidance control that controls the solid state relay so as to temporarily turn off the power supply before the leakage current detection time of the individual breaker has elapsed.

[0014] The heating control method of the present invention is a heating control method for controlling a heating device comprising one or more heater circuit units, a power supply unit that supplies power to the heater circuit unit, a main breaker electrically connected between the heater circuit unit and the power supply unit, and a control unit that controls the heater circuit unit, wherein the heater circuit unit includes a heater that heats the barrel of an injection molding machine and a solid state relay that turns on / off the power supply to the heater, and the main breaker includes a leakage current detector that can detect a leakage current in the heater circuit unit, and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detects the leakage current, and is characterized in that the solid state relay is controlled to temporarily turn off the power supply before the leakage current detection time has elapsed.

[0015] The heating control program of the present invention controls a heating device comprising one or more heater circuit units, a power supply unit that supplies power to the heater circuit unit, a main breaker electrically connected between the heater circuit unit and the power supply unit, and a control unit that controls the heater circuit unit, wherein the heater circuit unit includes a heater that heats the barrel of an injection molding machine and a solid state relay that turns on / off the power supply to the heater, and the main breaker includes a leakage current detector that can detect a leakage current in the heater circuit unit, and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detects the leakage current, and is characterized in that the heating control program causes the control unit to execute main breaker operation avoidance control that controls the solid state relay to temporarily turn off the power supply before the leakage current detection time has elapsed. Effect of the Invention

[0016] According to the present invention, it is possible to provide a heating device, a heating control method, and a heating control program capable of drying a heater that has absorbed moisture in a short period of time. [Brief description of the drawings]

[0017] [Figure 1]FIG. 1 is a schematic diagram showing an injection molding machine 1 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing an injection unit and a heating device according to the present embodiment. [Diagram 3] FIG. 2 is a functional block diagram showing the heating device according to the present embodiment. [Figure 4] FIG. 2 is a functional block diagram showing the heating device according to the present embodiment. [Diagram 5] 1 is an example of a circuit diagram showing a heating device according to an embodiment of the present invention. [Figure 6] 2 is a schematic diagram showing the functions of a leakage current detector and a breaker according to the present embodiment. FIG. [Figure 7] 4 is a schematic diagram showing a first main breaker operation avoidance control according to the present embodiment. FIG. [Figure 8] 6 is a schematic diagram showing a second main breaker operation avoidance control according to the present embodiment. FIG. [Figure 9] FIG. 11 is a schematic diagram showing a third main breaker operation avoidance control according to the present embodiment. [Figure 10] FIG. 13 is a diagram showing an example of a control screen when a heater is turned off according to the embodiment. [Figure 11] FIG. 13 is a diagram showing an example of a control screen when a heater is turned on according to the embodiment. [Figure 12] FIG. 13 is a diagram showing an example of a main breaker operation avoidance control selection screen according to the present embodiment. [Figure 13] FIG. 13 is a diagram showing an example of a control screen during main breaker operation avoidance control according to the present embodiment. [Figure 14] FIG. 13 is a diagram showing an example of a control screen during main breaker operation avoidance control according to the present embodiment. [Figure 15] 13 is a diagram showing an example of a control screen when the earth leakage detector of the main breaker according to the embodiment detects an earth leakage. FIG. [Figure 16] 13 is a diagram showing an example of a control screen when an individual breaker according to the embodiment detects a ground fault. FIG. [Figure 17] 5 is a flowchart illustrating an example of a heating control method according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The best mode for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. The drawings are schematic diagrams in which emphasis, omission, and ratio adjustments have been appropriately made to illustrate the present invention, and may differ from the actual shapes, positional relationships, and ratios.

[0019] [Configuration of the heating device according to this embodiment] First, a heating device 10 according to an embodiment of the present invention will be outlined. The heating device 10 according to this embodiment is a heating device used in an injection molding machine 1 including a clamping unit 2 and an injection unit 4, as shown in FIG. 1. The clamping unit 2 includes, for example, an operation panel 3 capable of operating the injection molding machine 1. The injection unit 4 includes, for example, a hopper 5 into which resin pellets as a material can be input, a barrel 6 that melts the resin pellets and fills them into a nozzle 7 described below, the nozzle 7 that injects the melted resin pellets, and a control panel 8 capable of controlling the injection molding machine 1.

[0020] 3, the heating device 10 includes a heater circuit section 100, a power supply section 40 that supplies power to the heater circuit section 100, a main breaker 50 electrically connected between the heater circuit section 100 and the power supply section 40, and a control section 60 that controls the heater circuit section 100. The heating device 10 also includes an electromagnetic contactor 52 electrically connected between the main breaker 50 and the heater circuit section 100, an input section 20, a display section 30, and a storage section 70. Furthermore, the heating device 10 may include a plurality of heater circuit sections 100 (first heater circuit section 100a to n-th heater circuit section 100n, n is an integer of 2 or more) as shown in FIG.

[0021] The input unit 20 is composed of input devices such as a keyboard, a mouse, a touch pad, a joystick, a push button switch, a toggle switch, a key lock switch, etc. By operating the input unit 20, the user can select whether or not to execute main breaker activation avoidance control, which will be described later, in addition to the function of inputting information normally required in the heating device 10.

[0022] The input unit 20 may have any of various configurations as long as the input unit 20 is configured to allow the user to switch between at least normal control and main breaker activation avoidance control, which will be described later. The input unit 20 may be included in the operation panel 3 of the mold clamping unit 2, as shown in FIG. 1, or may be included in a control device independent of the injection molding machine 1.

[0023] The display unit 30 has a display as a display device, and is configured to be able to identify whether or not main breaker activation avoidance control is being executed, in addition to the screen display function normally required in the heating device 10. The display unit 30 may be included in the operation panel 3 of the mold clamping unit 2, for example, as shown in FIG. 1, or may be included in a control device independent of the injection molding machine 1.

[0024] The display unit 30 is also configured to be able to display a control screen 200, as shown in Fig. 10. Fig. 10 shows a temperature setting tab of the control screen 200, and includes a control status display area 210, a heater circuit section display icon 220, and an alarm display area 230. The control status display area 210 is configured to be able to display the control status of the control unit 60. The heater circuit section display icon 220 is displayed for each heater circuit section 100, and below each heater circuit section display icon 220, an actual temperature measurement value of a temperature sensor 150 (to be described later) of the corresponding heater circuit section 100, a temperature setting value, an output value, an alarm display area 230, etc. are displayed.

[0025] Fig. 10 shows the display state of the control screen 200 when a heater OFF command from the control unit 60 opens the contacts of the electromagnetic contactor 52 as described below and turns off the power supply to the heater circuit unit 100 in a normal control state described below, and Fig. 11 shows the display state of the control screen 200 when a heater ON command from the control unit 60 closes the contacts of the electromagnetic contactor 52 as described below and turns on the power supply to the heater circuit unit 100. The control state display area 210 and the heater circuit unit display icon 220 are displayed in different colors depending on whether the power supply to the heater circuit unit 100 is ON or OFF, for example, as shown in Figs. 10 and 11.

[0026] 12, the display unit 30 is configured to be able to display a main breaker operation avoidance control selection screen 240. The main breaker operation avoidance control selection screen 240 includes a main breaker operation avoidance control selection button 242, a normal control switching temperature display area 244, a recovery delay time display area 246, and a delay time actual measurement display area 248. By pressing the main breaker operation avoidance control selection button 242, it is possible to select whether or not to execute main breaker operation avoidance control.

[0027] The normal control switching temperature display area 244 is configured to be able to display a normal control switching temperature T1, which will be described later. The normal control switching temperature display area 244 also has an input box, and the user can set the normal control switching temperature T1 to an arbitrary temperature by inputting a numerical value into the input box via the input unit 20.

[0028] The recovery delay time display area 246 is configured to be capable of displaying a recovery delay time, which will be described later, when switching from main breaker operation avoidance control to normal control. The recovery delay time display area 246 also has an input box, and the user can set the recovery delay time to an arbitrary time by inputting a numerical value into the input box via the input unit 20. The delay time actual measurement display area 248 is configured to be capable of displaying an actual measurement value of how much delay time has elapsed when switching from main breaker operation avoidance control to normal control.

[0029] In this embodiment, the main breaker operation avoidance control selection screen 240 is displayed superimposed on the control screen 200, but is not limited to this.

[0030] Fig. 13 shows the display state of the control screen 200 during main breaker operation avoidance control. The control status display area 210 and the heater circuit unit display icon 220 are displayed in a color different from that in the normal control state, for example, as shown in Fig. 13, during main breaker operation avoidance control. Furthermore, the control status display area 210 and the heater circuit unit display icon 220 may be configured to enable highlighting other than displaying in a different color, such as by flashing the display, so that the user can easily distinguish between normal control and main breaker operation avoidance control.

[0031] Fig. 14 shows tabs on the control screen 200 that are different from those shown in Figs. 10 to 13. When displaying a tab other than the temperature setting tab on the control screen 200 during main breaker activation avoidance control, the display unit 30 displays a pop-up screen 250 indicating that main breaker activation avoidance control is being executed, superimposed on the control screen 200, as shown in Fig. 14.

[0032] Furthermore, as shown in Fig. 15 and Fig. 16, when a leakage current detector 51 of the main breaker 50, which will be described later, and an individual breaker 130, which will be described later, detect a leakage current, the display unit 30 is configured to highlight the control status display area 210 and the alarm display area 230, and to notify the user of the occurrence of a leakage current. Specifically, as shown in Fig. 15, when the leakage current detector 51 of the main breaker 50 detects a leakage current, the display unit 30 highlights only the control status display area 210.

[0033] Furthermore, as shown in FIG. 16, when an individual breaker 130 detects a ground fault, the display unit 30 highlights the alarm display area 230 corresponding to the heater circuit unit 100 including the individual breaker 130.

[0034] Furthermore, the display unit 30 may be configured as a touch panel having the functions of the input unit 20. When the display unit 30 is configured as a touch panel, the user can select whether or not to execute main breaker activation avoidance control by operating the display unit 30, for example.

[0035] The configurations of the input unit 20 and the display unit 30 are not limited to the above-mentioned configurations, and any configuration having equivalent functions (e.g., a display means or input means that can be used remotely) can be used in place of the input unit 20 and the display unit 30, and is not limited to this.

[0036] The main breaker 50 is configured to automatically cut off an overcurrent equal to or greater than a specified value. As shown in Fig. 5, the main breaker 50 includes a leakage detector 51 capable of detecting leakage in the heater circuit section 100, and is configured to operate when a predetermined leakage detection time (for example, 100 milliseconds to 1000 milliseconds) has elapsed since the leakage detector 51 detected a leakage, as shown in Fig. 6. Specifically, the main breaker 50 is configured to operate a forced trip to cut off the current to the heater circuit 100 when a predetermined leakage detection time has elapsed since the leakage detector 51 detected a leakage current equal to or greater than a predetermined detection threshold.

[0037] In other words, the main breaker 50 will not operate if the leakage current detector 51 no longer detects a leakage current (if the leakage current falls below the detection threshold) before a specified leakage current detection time has elapsed since the leakage current detector 51 detected the leakage current.

[0038] In this embodiment, the leakage current detection time can be set by the user at any time using the main breaker 50, but is not limited to this, and the leakage current detection time may be fixed and not set at any time.

[0039] The electromagnetic contactor 52 is configured to open and close a contact to turn on / off the power supply to the heater circuit section 100. Specifically, the electromagnetic contactor 52 turns on the power supply to the heater circuit section 100 by closing the contact, and turns off the power supply to the heater circuit section 100 by opening the contact.

[0040] As shown in Fig. 3, the heater circuit section 100 includes a heater 110 and a solid state relay (SSR) 140. The heater circuit section 100 also includes a temperature sensor 150. The heater circuit section 100 further includes an individual breaker 130. As shown in Fig. 5, in the heater circuit section 100, the solid state relay 140 is electrically connected between the power supply section 40 and the heater 110. In the heater circuit section 100, the individual breaker 130 is also electrically connected between the main breaker 50 and the solid state relay 140.

[0041] 2, the heater 110 is configured to be attached to, for example, a surface of the barrel 6 of the injection unit 4 of the injection molding machine 1 and heat the barrel 6. Specifically, the heater 110 is configured to heat the outer periphery of the barrel 6 and to heat the inside of the barrel 6 by thermal conduction, thereby melting the resin pellets. In this embodiment, the heater 110 is a cylindrical band heater that is wrapped around the barrel 6, but is not limited to this. The heater 110 can adopt any of various configurations as long as it is configured to heat the barrel 6.

[0042] The individual breaker 130 is configured to automatically cut off an overcurrent equal to or greater than a specified value. In this embodiment, the individual breaker 130 has a leakage current detection function capable of detecting leakage current from the heater 110, and is configured to operate when a predetermined leakage current detection time (e.g., 100 milliseconds) has elapsed since the leakage current was detected. Specifically, the individual breaker 130 is configured to operate when the leakage current detection time has elapsed since the leakage current was detected as being equal to or greater than a predetermined detection threshold.

[0043] In other words, if the individual breaker 130 no longer detects a leak before a predetermined leak detection time has elapsed since the detection of the leak (if the leakage current falls below the detection threshold), the individual breaker 130 will not operate.

[0044] In this embodiment, the leakage current detection time of the individual breaker 130 is fixed and the leakage current detection time cannot be set to any time, but this is not limited thereto, and the individual breaker 130 may be configured to allow the user to set the leakage current detection time to any time.

[0045] The individual breaker 130 may be a breaker that does not have a leakage current detection function.

[0046] The solid state relay 140 is configured to turn on / off the power supply to the heater 110. Specifically, the solid state relay 140 is configured to turn on / off the output voltage in response to a signal from the control unit 60.

[0047] In this embodiment, the temperature sensor 150 is inserted from the surface of the barrel 6 of the injection unit 4 of the injection molding machine 1 into the inside of the barrel 6 and measures the temperature inside the barrel 6, but is not limited to this. For example, the temperature sensor 150 may measure the temperature on the surface of the barrel 6 or inside the nozzle 7.

[0048] The control unit 60 may be included in a control panel 8 of the injection unit 4 as shown in Fig. 1, for example, or may be included in a control device independent of the injection molding machine 1. The control unit 60 is configured to be able to acquire an actual temperature measurement value of the temperature sensor 150. The control unit 60 is also configured to be able to control the ON / OFF of the output voltage of the solid-state relay 140. Specifically, the control unit 60 transmits a signal to the solid-state relay 140 to turn the output voltage ON / OFF. The control unit 60 is also configured to be able to control the opening and closing of the contacts of the electromagnetic contactor 52.

[0049] The control unit 60 is also configured to be capable of feedback-controlling the solid-state relay 140 so that the actual temperature measurement value approaches a preset temperature setting value. The control unit 60 is configured to be capable of executing normal control to control the heater circuit unit 100 so that the actual temperature measurement value becomes a predetermined normal control target temperature T2. In this embodiment, the normal control target temperature T2 is a temperature at which the pellets in the barrel 6 can be melted by heating with the heater 110, and is higher than a normal control switching temperature T1 described later.

[0050] The control unit 60 is also configured to be capable of executing main breaker operation avoidance control for controlling the solid state relay 140 to temporarily turn off the power supply to the heater 110 before the leakage detection time of the leakage detector 51 of the main breaker 50 has elapsed. Furthermore, the control unit 60 is configured to be capable of executing individual breaker operation avoidance control for controlling the solid state relay 140 to temporarily turn off the power supply before the leakage detection time of the individual breaker 130 has elapsed. In other words, the main breaker operation avoidance control and the individual breaker operation avoidance control are characterized in that the output voltage of the solid state relay 140 is not kept ON (the voltage application is not made 100% (continuous energization state)).

[0051] The heating control device described in Patent Document 1 normally applies a voltage of 200V, and during dehumidification, by utilizing the fact that the leakage current also decreases by lowering the applied voltage, applies a voltage of, for example, 50V, but the main breaker operation avoidance control according to this embodiment is configured to apply the same voltage (for example, 200V) as during normal control. Furthermore, when the heating device 10 has multiple heater circuit units 100a to 100n, the control unit 60 is configured to be able to execute main breaker operation avoidance control for each heater circuit unit 100.

[0052] In the main breaker operation avoidance control, the control unit 60 controls the heater circuit unit 100 so that the actual temperature measurement value becomes a predetermined normal control switching temperature T1. In this embodiment, the normal control switching temperature T1 is a temperature at which the heater 110 is dry and no leakage due to moisture is expected to occur.

[0053] It is preferable that the normal control switching temperature T1 is as small as possible so as to shorten the time until switching to normal control. However, if it is set to a value that is too small, the control will switch to normal control before the heater 110 is completely dry, and there is a risk that the earth leakage detector 51 of the main breaker 50 will be activated immediately after switching. As a guideline, it is preferable that the normal control switching temperature T1 is set to a value larger than 100°C, which is the boiling point of water.

[0054] The control unit 60 according to this embodiment is configured to be capable of executing a first main breaker operation avoidance control that avoids operation of the main breaker 50 by ON / OFF control, and a second main breaker operation avoidance control and a third main breaker operation avoidance control that avoid operation of the main breaker 50 by proportional control. Each main breaker operation avoidance control will be described in detail below.

[0055] [First main breaker operation avoidance control] 7, the control unit 60 controls the solid state relay 140 so as to repeatedly turn off the power supply to the heater 110 at a period shorter than the leakage current detection time during main breaker operation avoidance control. Specifically, the control unit 60 applies a voltage to the heater 110 while preventing the main breaker 50 from detecting a leakage current and forcibly tripping by making the solid state relay 140 switch the power supply to the heater 110 on and off at a period that can avoid the operation of the main breaker 50.

[0056] First, the control unit 60 determines the leakage current detection time (t d The output voltage of the solid-state relay 140 is turned ON for a time (s seconds in this embodiment) shorter than a predetermined delay time (s seconds). After s seconds have elapsed, the control unit 60 turns the output voltage of the solid-state relay 140 OFF, and maintains this OFF state for a predetermined delay time (OFF time). Then, after the delay time has elapsed, the control unit 60 turns the output voltage of the solid-state relay 140 ON again, and repeats this control. The value of s is 0 <s<t d It is.

[0057] As described above, the first main breaker operation avoidance control turns off the power supply to the heater 110 before the leakage current detection time has elapsed, thereby preventing the main breaker 50 from operating while increasing the temperature of the heater 110 and drying the heater 110.

[0058] [Second main breaker activation avoidance control and third main breaker activation avoidance control] Next, the second main breaker operation avoidance control and the third main breaker operation avoidance control will be described. In the second main breaker operation avoidance control and the third main breaker operation avoidance control, the control unit 60 is configured to be capable of proportionally controlling the solid state relay 140 so that the actual temperature measurement value approaches a preset temperature set value. The control period of the solid state relay 140 in the proportional control during the main breaker operation avoidance control is set to be equal to or shorter than the leakage current detection time. Note that the proportional control is preferably PID control, but is not limited to this.

[0059] Specifically, in proportional control, the control unit 60 is configured to cause the solid-state relay 140 to keep the power supply to the heater 110 ON when the acquired actual temperature measurement value is lower than the proportional band, and to cause the solid-state relay 140 to keep the power supply to the heater 110 OFF when the actual temperature measurement value is higher than the proportional band. Also, the control unit 60 is configured to always perform ON / OFF switching of the output voltage of the solid-state relay 140 within the proportional control period of the solid-state relay 140 (within the temperature control period of the heater 110) if the actual temperature measurement value is within the proportional band of the proportional control.

[0060] If the measured temperature value is within the proportional band of the proportional control, the output voltage of the solid-state relay 140 is always switched ON / OFF, so in this embodiment, the control unit 60 executes proportional control at a period equal to or shorter than the leakage detection time of the leakage detector 51 of the main breaker 50. This makes it possible to increase the temperature of the heater 110 while avoiding the operation of the main breaker 50.

[0061] More specifically, the control unit 60 is configured to be able to proportionally control the solid-state relay 140 so that the following formula 1 holds.

number

[0062] In Equation 1, T s is the temperature setting, T a is the actual temperature measurement value. Furthermore, P is a proportional temperature value indicating the upper and lower widths of the proportional band, and U is an adjustment value that adjusts the actual temperature measurement value so that it remains within the proportional band. That is, as shown in Equation 1, the control unit 60 sets the temperature set value to be the sum of the actual temperature measurement value and a value (PU) smaller than the proportional temperature value. Furthermore, as the actual temperature measurement value increases, the control unit 60 increases the temperature set value so as not to deviate from the proportional band. Specific methods of changing the temperature set value in the second main breaker operation avoidance control and the third main breaker operation avoidance control are as follows.

[0063] [Second main breaker operation avoidance control] As shown in Fig. 8, the control unit 60 is configured to proportionally control the solid-state relay 140 while constantly changing the temperature set value so that the actual temperature measurement value falls within the proportional band. Specifically, in the second main breaker operation avoidance control, the control unit 60 calculates the above-mentioned formula 1 at the control period of the control unit 60 or at a predetermined period (e.g., 0.1 to 1.0 seconds) to change the temperature set value. The control unit 60 may also calculate the above-mentioned formula 1 at each predetermined temperature rise (e.g., 0.1°C) to change the temperature set value. In this case, since the degree of temperature rise is affected by the adjustment value of formula 1 and the specific heat of the entire barrel 6, it is preferable to find an appropriate period by measuring the actual injection molding machine 1 using the heating device 10 and manage it as a parameter for each injection molding machine 1.

[0064] [Third main breaker operation avoidance control] 9, the control unit 60 is configured to proportionally control the solid-state relay 140 while increasing the temperature set value stepwise so that the actual temperature measurement value falls within the proportional band. Specifically, when the actual temperature measurement value approaches the temperature set value, the control unit 60 increases the temperature set value stepwise within the range that satisfies the above-mentioned formula 1.

[0065] In addition, in the main breaker operation avoidance control according to this embodiment, although the leakage current exceeds the detection threshold for a short period of time, the risk of electric shock accident due to the extremely short leakage current is small because this is a situation in which the leakage current detector 51 of the main breaker 50 does not operate and because Class C or Class D grounding is mandatory when installing the injection molding machine 1 according to an ordinance of the Ministry of Economy, Trade and Industry, etc.

[0066] The control unit 60 is configured to execute a temperature acquisition process (S1 in FIG. 17) for acquiring the actual temperature value of the temperature sensor 150, a normal control switching temperature determination process (S2 in FIG. 17) for determining whether the actual temperature value is equal to or higher than a predetermined normal control switching temperature, a control switching process (S3 in FIG. 17) for switching the control of the heater circuit unit 100 to normal control if the actual temperature value is equal to or higher than the normal control switching temperature T1 (YES in S2 in FIG. 17), and a control continuation process (S4 in FIG. 17) for continuing the main breaker operation avoidance control if the actual temperature value is less than the normal control switching temperature T1 (NO in S2 in FIG. 17).

[0067] Specifically, in the temperature acquisition process, the control unit 60 acquires the actual temperature measurement value of the temperature sensor 150 as described above. The acquired actual temperature measurement value is displayed on the control screen 200 of the display unit 30. Furthermore, as shown in FIG. 8 and other figures, if the acquired actual temperature measurement value is equal to or higher than the normal control switching temperature T1, the control unit 60 determines that the heater 110 is dry and switches the control of the heater circuit unit 100 to normal control. Furthermore, if the acquired actual temperature measurement value is lower than the normal control switching temperature T1, the control unit 60 determines that the heater 110 is not dry and continues the main breaker operation avoidance control until the actual temperature measurement value becomes equal to or higher than the normal control switching temperature T1.

[0068] In addition, when the heating device 10 includes a plurality of heater circuit sections 100, the control section 60 switches the control of each heater circuit section 100 to normal control when the actual temperature measurements of all the temperature sensors 150 are equal to or higher than the normal control switching temperature T1, but is not limited to this. The control section 60 may switch the control of the heater circuit sections 100 to normal control in order, starting from the heater circuit section 100 including the temperature sensor 150 whose actual temperature measurement is equal to or higher than the normal control switching temperature T1.

[0069] In the control switching process, the control unit 60 is configured to be able to set a return delay time that delays the time to switch from main breaker operation avoidance control to normal control. The return delay time can be set, for example, to 0 to 100 seconds. When the return delay time is set, the control unit 60 continues the main breaker operation avoidance control for a predetermined return delay time after the actual temperature measurement value becomes equal to or higher than the normal control switching temperature T1, and switches the control of the heater circuit unit 100 to normal control after the return delay time has elapsed. Note that the control unit 60 does not necessarily have to be able to set the return delay time.

[0070] In addition, the control unit 60 is configured to execute a leakage current determination process (S5 in FIG. 17) for determining whether or not the leakage current detector 51 of the main breaker 50 has detected a leakage current after the control switching process, an abnormality determination process (S6 in FIG. 17) for determining that the leakage current is an abnormality caused by insulation deterioration of the heater 110 if it is determined that a leakage current has been detected, and a warning process (S7 in FIG. 17) for warning the user of the abnormality.

[0071] Specifically, after the control switching process, i.e., in the normal control state, when the control unit 60 determines that the leakage detector 51 of the main breaker 50 has detected a leakage, it determines that the leakage is not due to condensation but due to insulation deterioration of the heater 110, and warns the user of the abnormality. In this embodiment, the control unit 60 displays the fact that there is a leakage in the control status display area 210 of the control screen 200 as shown in Fig. 15, and warns the user of the abnormality, but is not limited to this. For example, the control unit 60 may warn of the abnormality by voice.

[0072] Furthermore, the control unit 60 is configured to be able to execute, after the abnormality determination process, an emergency control process (S8 in FIG. 17) for switching the control of the heater circuit unit 100 to main breaker operation avoidance control, a normal control target temperature determination process (S9 in FIG. 17) for determining whether the actual temperature measurement value is equal to or higher than a predetermined normal control target temperature T2 which is higher than the normal control switching temperature T1, an emergency control termination process (S10 in FIG. 17) for switching the control of the heater circuit unit 100 back to normal control if the actual temperature measurement value is equal to or higher than the normal control target temperature T2, and an emergency control continuation process (S11 in FIG. 17) for continuing the main breaker operation avoidance control if the actual temperature measurement value is less than the normal control target temperature T2.

[0073] Specifically, when the control unit 60 determines that the earth leakage detector 51 of the main breaker 50 has detected an earth leakage in the normal control state, the control unit 60 again switches the control of the heater circuit unit 100 to the main breaker operation avoidance control in order to avoid the operation of the main breaker 50. Then, the control unit 60 controls the heater circuit unit 100 with the main breaker operation avoidance control, and continues heating the heater 110 until the actual temperature measurement value acquired from the temperature sensor 150 becomes equal to or higher than the normal control target temperature T2.

[0074] Thereafter, if the actual temperature measurement value acquired from the temperature sensor 150 is equal to or higher than the normal control target temperature T2, the control unit 60 switches the control of the heater circuit unit 100 back to normal control. If the actual temperature measurement value acquired is lower than the normal control target temperature T2, the control unit 60 continues the main breaker operation avoidance control until the actual temperature measurement value becomes equal to or higher than the normal control target temperature T2.

[0075] In addition, the control unit 60 may be configured to accept a selection of whether or not to execute the emergency control processing after the abnormality judgment processing and before executing the emergency control processing, and if the user selects to execute the emergency control processing, the control unit 60 may execute the emergency control processing and processing associated with the emergency control processing.

[0076] The storage unit 70 has a storage medium such as an HDD, an SSD, etc., and stores various data in a readable and writable manner. The storage unit 70 stores a heating control program 72 as shown in Fig. 3 and Fig. 4. The heating control program 72 is a heating control program for controlling the heating device 10, and causes the control unit 60 to execute main breaker operation avoidance control for controlling the solid state relay 140 to temporarily turn off the power supply before the leakage detection time has elapsed.

[0077] [Explanation of heating control method] A heating control method for the barrel 6 using the heating device 10 according to this embodiment will be described with reference to Fig. 17. Fig. 17 is a flowchart showing an example of a procedure for heating control using the heating device 10 according to this embodiment. The heating control method according to this embodiment is generally a heating control method for controlling the heating device 10, and controls the solid state relay 140 of the heater circuit unit 100 so as to temporarily turn off the power supply before the leakage detection time has elapsed.

[0078] This method will be described in detail below. In the following description, the main breaker operation avoidance control will be described as the above-mentioned first main breaker operation avoidance control, but is not limited to this and may be the second main breaker operation avoidance control or the third main breaker operation avoidance control.

[0079] First, the control unit 60 of the heating device 10 controls the electromagnetic contactor 52 to turn on the power supply to the heater circuit unit 100. The control unit 60 also controls the solid state relay 140 to turn on the power supply to the heater 110. Then, the control unit 60 determines whether or not the leakage detector 51 of the main breaker 50 has detected a leakage from the heater 110 (leakage detection and determination process). If it is determined that a leakage has not been detected, the control unit 60 continues the power supply to the heater 110 (power supply continuation process).

[0080] On the other hand, when it is determined that a leakage current has been detected, the control unit 60 controls the solid-state relay 140 to temporarily turn off the power supply to the heater 110 before a predetermined leakage current detection time has elapsed since the leakage current detector 51 of the main breaker 50 detected the leakage current (breaker activation avoidance process).Then, after the delay time has elapsed, the control unit 60 controls the solid-state relay 140 to turn on the power supply to the heater 110 again (power supply resumption process).

[0081] The control unit 60 repeatedly executes the steps from the leakage detection determination step to the power supply resumption step, and increases the temperature of the heater 110 so that the condensed heater 110 dries while avoiding the main breaker 50 from operating. Specifically, the control unit 60 acquires the actual temperature value of the temperature sensor 150 (actual temperature value acquisition step: S1 in FIG. 17). The control unit 60 judges whether the acquired actual temperature value is equal to or higher than the normal control switching temperature T1 (normal control switching temperature judgment step: S2 in FIG. 17).

[0082] If the actual temperature measurement value is equal to or higher than the normal control switching temperature T1 (YES in S2 in FIG. 17), the control unit 60 determines that the heater 110 is dry, and switches the control of the heater circuit unit 100 to normal control (control switching step: S3 in FIG. 17). If the acquired actual temperature measurement value is lower than the normal control switching temperature T1 (NO in S2 in FIG. 17), the control unit 60 determines that the heater 110 is not dry, and continues the main breaker operation avoidance control until the actual temperature measurement value becomes equal to or higher than the normal control switching temperature T1 (control continuing step: S4 in FIG. 17).

[0083] After the control switching step, the control unit 60 executes normal control to control the heater circuit unit 100 so that the actual temperature measurement value becomes equal to or higher than the normal control target temperature T2. After switching from the main breaker operation avoidance control to the normal control, the control unit 60 determines whether or not the leakage current detector 51 of the main breaker 50 has detected a leakage current (leakage current determination step: S5 in FIG. 17). If it is determined that a leakage current has not been detected (NO in S5 in FIG. 17), the control unit 60 continues the normal control as is.

[0084] On the other hand, when it is determined that a leakage current has been detected (YES in S5 in FIG. 17), the control unit 60 determines that the leakage current is an abnormality caused by insulation deterioration of the heater 110 (abnormality determination step: S6 in FIG. 17), and warns the user of the abnormality (warning step: S7 in FIG. 17). Furthermore, the control unit 60 again switches the control of the heater circuit unit 100 to main breaker operation avoidance control in order to avoid the main breaker 50 from operating (emergency control step: S8 in FIG. 17).

[0085] Thereafter, the control unit 60 controls the heater circuit unit 100 using main breaker operation avoidance control to continue heating the heater 110. Furthermore, the control unit 60 determines whether the actual temperature measurement value is equal to or higher than the normal control target temperature T2 (normal control target temperature determination step: S9 in FIG. 17). If the actual temperature measurement value is equal to or higher than the normal control target temperature T2 (YES in S9 in FIG. 17), the control of the heater circuit unit 100 is switched back to normal control (emergency control termination step; S10 in FIG. 17).

[0086] On the other hand, if the actual temperature measurement value is lower than the normal control target temperature T2 (NO in S9 in FIG. 17), the control unit 60 continues the main breaker operation avoidance control until the actual temperature measurement value becomes equal to or higher than the normal control target temperature T2 (emergency control continuation step: S11 in FIG. 17). Through the above steps, a series of heating control methods by the heating device 10 according to this embodiment are performed.

[0087] [Advantages of the heating device, heating control method, and heating control program according to the present embodiment] As described above, the heating device 10 according to this embodiment includes one or more heater circuit sections 100, a power supply section 40 that supplies power to the heater circuit section 100, a main breaker 50 electrically connected between the heater circuit section 100 and the power supply section 40, and a control section 60 that controls the heater circuit section 100. The heater circuit section 100 includes a heater 110 that heats the barrel 6 of the injection molding machine 1, and a solid state relay 140 that turns on / off the power supply to the heater 110. The main breaker 50 includes a leakage current detector 51 that can detect a leakage current in the heater circuit section 100 and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector 51 detected a leakage current. The control section 60 is configured to be capable of executing main breaker operation avoidance control that controls the solid state relay 140 to temporarily turn off the power supply before the leakage current detection time has elapsed.

[0088] And, by being provided with such a configuration, the heating device 10 according to this embodiment temporarily turns off the power supply to the heater 110 before the main breaker 50 operates even if the leakage current detector 51 detects a leakage current, so that it is possible to raise the temperature of the moisture-absorbed heater 110 without lowering the voltage applied to the heater 110 while avoiding the operation of the main breaker 50. This has the advantage that it is possible to dry the heater 110 in a short time compared to disassembling the heater 110 alone from the injection molding machine 1 and drying it, or lowering the voltage applied to the heater 110 as in the invention described in Patent Document 1.

[0089] Furthermore, in the heating device 10 according to this embodiment, the control unit 60 controls the solid state relay 140 to repeatedly turn off the power supply at a period shorter than the leakage detection time during main breaker operation avoidance control. With this configuration, even if the leakage detector 51 repeatedly detects leakage, the main breaker 50 is prevented from operating while the temperature of the heater 110 can be increased, which has the advantage that the heater 110 that has absorbed moisture can be dried in a short time.

[0090] Furthermore, in the heating device 10 according to this embodiment, the heater circuit section 100 includes a temperature sensor 150, and the control section 60 is configured to be able to acquire an actual temperature measurement value of the temperature sensor 150 and to be able to proportionally control the solid-state relay 140 so that the actual temperature measurement value approaches the temperature set value, and the control period of the solid-state relay 140 in the proportional control is set to be equal to or shorter than the leakage detection time. With this configuration, the control section 60 controls the solid-state relay 140 so as to switch the power supply to the heater 110 on and off at a period equal to or shorter than the leakage detection time, so that even if the leakage detector 51 repeatedly detects leakage, the temperature of the heater 110 can be increased while avoiding the main breaker 50 from operating, and the heater 110 that has absorbed moisture can be dried in a short time.

[0091] Furthermore, in the heating device 10 according to this embodiment, the control unit 60 is configured to proportionally control the solid-state relay 140 while constantly changing the temperature setting value so that the actual temperature measurement value falls within the proportional band. With this configuration, even if the leakage detector 51 repeatedly detects leakage, the main breaker 50 is prevented from operating, and the temperature of the heater 110 can be increased, which has the advantage of making it possible to dry the heater 110 that has absorbed moisture in a short time.

[0092] Furthermore, in the heating device 10 according to this embodiment, the control unit 60 is configured to proportionally control the solid-state relay 140 while gradually increasing the temperature setting value so that the actual temperature measurement value falls within the proportional band. With this configuration, even if the leakage detector 51 repeatedly detects leakage, the main breaker 50 is prevented from operating, and the temperature of the heater 110 can be increased, which has the advantage of making it possible to dry the heater 110 that has absorbed moisture in a short time.

[0093] In the heating device 10 according to the present embodiment, the heater circuit section 100 includes a temperature sensor 150, and the control section 60 is configured to be able to execute a temperature acquisition process for acquiring an actual temperature measurement value of the temperature sensor 150, a normal control switching temperature determination process for determining whether or not the actual temperature measurement value is equal to or higher than a predetermined normal control switching temperature, a control switching process for switching the control of the heater circuit section 100 to normal control when the actual temperature measurement value is equal to or higher than the normal control switching temperature, and a control continuation process for continuing the main breaker operation avoidance control when the actual temperature measurement value is lower than the normal control switching temperature. With such a configuration, the heater 110 can be automatically switched to normal control after drying to heat the heater 110, which has the advantage of being able to raise the temperature of the heater 110 to the temperature setting value in normal control in a short time.

[0094] Furthermore, in the heating device 10 according to this embodiment, the control unit 60 is configured to be able to execute a leakage current determination process for determining whether or not the leakage current detector 51 detects leakage current after the control switching process, an abnormality determination process for determining that the leakage current is an abnormality caused by insulation deterioration of the heater 110 when it is determined that leakage current has been detected, and a warning process for warning the user of the abnormality. By being provided with such a configuration, it has the advantage of being able to immediately notify the user that insulation deterioration has occurred in the heater 110.

[0095] Furthermore, in the heating device 10 according to the present embodiment, the control unit 60 is configured to be able to execute, after the abnormality determination process, an emergency control process for switching the control of the heater circuit unit 100 to the main breaker operation avoidance control, a normal control target temperature determination process for determining whether or not the actual temperature measurement value is equal to or higher than a predetermined normal control target temperature T2 higher than the normal control switching temperature T1, an emergency control end process for switching the control of the heater circuit unit 100 to normal control again when the actual temperature measurement value is equal to or higher than the normal control target temperature T2, and an emergency control continuation process for continuing the main breaker operation avoidance control when the actual temperature measurement value is lower than the normal control target temperature T2. With such a configuration, even if the insulation of the heater 110 has deteriorated and needs to be replaced, it takes time to order a new heater 110 and to replace it, so that when there is urgent work that cannot wait for the replacement of the heater 110, it is possible to continue the work by heating the barrel 6 to the normal control target temperature T2 using the main breaker operation avoidance control as an emergency measure.

[0096] Furthermore, the heating device 10 according to the present embodiment includes an input unit 20 that allows the user to select whether or not to execute the main breaker activation avoidance control. With this configuration, the user can manually select whether or not to execute the main breaker activation avoidance control, which has the advantage that, for example, the main breaker activation avoidance control is executed only when condensation on the heater 110 is visually confirmed, and when condensation is not present, the barrel 6 can be heated to the normal control target temperature T2 in a short time by normal control.

[0097] Furthermore, the heating device 10 according to this embodiment includes a display unit 30 that can identify whether the control unit 60 is executing main breaker activation avoidance control. By including such a configuration, it has an advantage that it is immediately obvious whether normal control or main breaker activation avoidance control is being executed.

[0098] Furthermore, in the heating device 10 according to this embodiment, each heater circuit section 100 includes an individual breaker 130, which has a leakage current detection function and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detection, and the control section 60 is configured to be capable of executing individual breaker operation avoidance control for controlling the solid state relay 140 to temporarily turn off the power supply before the leakage current detection time of the individual breaker 130 has elapsed. By providing such a configuration, there is an advantage that it is possible to individually grasp which heater 110 is leaking current.

[0099] [Variations] Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiments. Various modifications and improvements can be made to the above-mentioned embodiments.

[0100] For example, in the above embodiment, the control unit 60 is described as controlling the solid-state relay 140 to repeatedly turn off the power supply at a period shorter than the leakage detection time during the main breaker operation prevention control, but this is not limited to this. The control unit 60 does not have to repeatedly turn off the power supply at a period during the main breaker operation prevention control.

[0101] In the above-described embodiment, the heater circuit section 100 includes the temperature sensor 150, the control section 60 is configured to be able to acquire the actual temperature value of the temperature sensor 150, and is configured to be able to proportionally control the solid-state relay 140 so that the actual temperature value approaches the temperature set value, and the control period of the solid-state relay 140 in the proportional control is set to be equal to or shorter than the leakage detection time, but this is not limiting. The heater circuit section 100 does not need to include the temperature sensor 150. Furthermore, the control section 60 does not need to be able to perform proportional control.

[0102] In the above embodiment, the control unit 60 is configured to proportionally control the solid-state relay 140 while constantly changing the temperature set value so that the actual temperature measurement value falls within the proportional band, but is not limited to this. The control unit 60 does not have to proportionally control the solid-state relay 140 while constantly changing the temperature set value so that the actual temperature measurement value falls within the proportional band.

[0103] In the above embodiment, the control unit 60 is described as being configured to proportionally control the solid-state relay 140 while gradually increasing the temperature setting value so that the actual temperature measurement value falls within the proportional band, but is not limited to this. The control unit 60 does not have to proportionally control the solid-state relay 140 while gradually increasing the temperature setting value so that the actual temperature measurement value falls within the proportional band.

[0104] In the above-described embodiment, the heater circuit unit 100 includes the temperature sensor 150, and the control unit 60 is configured to execute a temperature acquisition process for acquiring an actual temperature measurement value of the temperature sensor 150, a normal control switching temperature determination process for determining whether or not the actual temperature measurement value is equal to or higher than a predetermined normal control switching temperature, a control switching process for switching the control of the heater circuit unit 100 to normal control when the actual temperature measurement value is equal to or higher than the normal control switching temperature, and a control continuation process for continuing the main breaker operation avoidance control when the actual temperature measurement value is lower than the normal control switching temperature. However, the present invention is not limited to this. The control unit 60 may not be able to execute the normal control switching temperature determination process and the control switching process. For example, an operator may visually confirm a temperature rise of the heater 110, consider the heater 110 to be dry, and manually switch to normal control.

[0105] In the above embodiment, the control unit 60 has been described as being configured to be able to execute a leakage current determination process for determining whether or not the leakage current detector 51 has detected a leakage current after the control switching process, an abnormality determination process for determining that the leakage current is an abnormality caused by insulation deterioration of the heater 110 when it is determined that a leakage current has been detected, and a warning process for warning the user of the abnormality, but is not limited thereto. The control unit 60 does not necessarily have to be able to execute the leakage current determination process, the abnormality determination process, and the warning process.

[0106] In the above embodiment, the control unit 60 is described as being configured to be able to execute, after the abnormality determination process, an emergency control process for switching the control of the heater circuit unit 100 to main breaker activation avoidance control, a normal control target temperature determination process for determining whether or not the actual temperature measurement value is equal to or higher than a predetermined normal control target temperature T2 higher than the normal control switching temperature T1, an emergency control end process for switching the control of the heater circuit unit 100 back to normal control if the actual temperature measurement value is equal to or higher than the normal control target temperature T2, and an emergency control continuation process for continuing the main breaker activation avoidance control if the actual temperature measurement value is lower than the normal control target temperature T2, but this is not limiting. The control unit 60 does not necessarily have to be able to execute the emergency control process, the normal control target temperature determination process, the emergency control end process, and the emergency control continuation process.

[0107] In the above-described embodiment, the heating device 10 has been described as having an input unit 20 that allows the user to select whether or not to execute main breaker activation avoidance control, but this is not limited to this, and the heating device 10 does not need to have an input unit 20.

[0108] In the above-described embodiment, the heating device 10 has been described as being equipped with a display unit 30 that can identify whether or not the control unit 60 is executing main breaker activation avoidance control, but this is not limited thereto, and the heating device 10 does not need to be equipped with a display unit 30.

[0109] In the above-described embodiment, each heater circuit unit 100 includes an individual breaker 130, the individual breaker 130 has a leakage detection function and is configured to operate when a predetermined leakage detection time has elapsed since the leakage detection, and the control unit 60 is configured to be able to execute individual breaker operation avoidance control for controlling the solid state relay 140 to temporarily turn off the power supply before the leakage detection time of the individual breaker 130 has elapsed, but this is not limiting. Each heater circuit unit 100 does not have to include an individual breaker 130. [Explanation of symbols]

[0110] 1 injection molding machine 2 Clamping unit 3 Control panel 4. Injection unit 5. Hopper 6 barrel 7 Nozzles 8 Control Panel 10 Heating device 20 Input section 30 Display section 40 Power supply section 50 Main Breaker 51 Earth leakage detector 52 Magnetic contactor 60 Control section 70 Storage section 72 Heating control program 100,100a~100n Heater circuit section 110 Heater 130 Individual breaker 140 Solid State Relay 150 Temperature Sensor 200 Control Screen 210 Control status display area 220 Heater circuit display icon 230 Alarm display area 240 Main breaker operation avoidance control selection screen 242 Main breaker operation avoidance control selection button 244 Normal control switching temperature display area 246 Recovery delay time display area 248 Delay time measurement display area 250 Pop-up screens T1 Normal control switching temperature T2 Normal control target temperature

Claims

1. One or more heater circuits; a power supply unit that supplies power to the heater circuit unit; a main breaker electrically connected between the heater circuit unit and the power supply unit; A control unit for controlling the heater circuit unit; Equipped with The heater circuit unit includes: a heater for heating the barrel of the injection molding machine; a solid state relay that turns on / off the power supply to the heater; Including, the main breaker includes a leakage current detector capable of detecting leakage current in the heater circuit portion, and is configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detected the leakage current, The control unit is configured to be capable of executing main breaker operation avoidance control for controlling the solid state relay so as to temporarily turn off the power supply before the leakage current detection time has elapsed. A heating device characterized by:

2. The control unit controls the solid state relay so as to repeatedly turn off the power supply at a period shorter than the leakage detection time during the main breaker operation avoidance control.

2. The heating device according to claim 1 .

3. the heater circuit portion includes a temperature sensor, the control unit is configured to be able to acquire an actual temperature measurement value of the temperature sensor and to be able to proportionally control the solid-state relay so that the actual temperature measurement value approaches a temperature setting value; The control period of the solid state relay in the proportional control is set to be equal to or shorter than the earth leakage detection time.

3. The heating device according to claim 1 or 2.

4. the heater circuit portion includes a temperature sensor, The control unit is a temperature acquisition process for acquiring an actual temperature measurement value of the temperature sensor; a normal control switching temperature determination process for determining whether or not the actual temperature measurement value is equal to or higher than a predetermined normal control switching temperature; a control switching process for switching the control of the heater circuit unit to normal control when the actual temperature measurement value is equal to or higher than the normal control switching temperature; When the actual temperature measurement value is less than the normal control switching temperature, a control continuation process is performed to continue the main breaker operation avoidance control. is configured to run 3. The heating device according to claim 1 or 2.

5. The control unit is a leakage current determination process for determining whether or not the leakage current detector detects the leakage current after the control switching process; an abnormality determination process for determining that the electric leakage is an abnormality caused by insulation deterioration of the heater when it is determined that the electric leakage is detected; a warning process for warning a user of the abnormality; is configured to run 5. The heating device according to claim 4.

6. The control unit is an emergency control process for switching control of the heater circuit unit to the main breaker operation avoidance control after the abnormality determination process; a normal control target temperature determination process for determining whether the actual temperature measurement value is equal to or higher than a predetermined normal control target temperature that is higher than the normal control switching temperature; an emergency control end process for switching the control of the heater circuit unit back to normal control when the actual temperature measurement value is equal to or higher than the normal control target temperature; When the actual temperature measurement value is lower than the normal control target temperature, an emergency control continuation process is performed to continue the main breaker operation avoidance control. is configured to run 6. The heating device according to claim 5.

7. Each heater circuit section includes an individual breaker; The individual breaker has a leakage current detection function and is configured to operate when a predetermined leakage current detection time has elapsed since detecting a leakage current, The control unit is configured to be capable of executing individual breaker operation avoidance control for controlling the solid state relay so as to temporarily turn off the power supply before the leakage detection time of the individual breaker has elapsed.

3. The heating device according to claim 1 or 2.

8. a power supply unit that supplies power to the heater circuit unit, a main breaker that is electrically connected between the heater circuit unit and the power supply unit, and a control unit that controls the heater circuit unit, the heater circuit unit including a heater that heats a barrel of an injection molding machine, and a solid state relay that switches on / off power supply to the heater, the main breaker including a leakage current detector that can detect leakage current in the heater circuit unit, the main breaker being configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detected the leakage current, The solid state relay is controlled so as to temporarily turn off the power supply before the leakage current detection time has elapsed. A heating control method comprising:

9. a power supply unit that supplies power to the heater circuit unit, a main breaker that is electrically connected between the heater circuit unit and the power supply unit, and a control unit that controls the heater circuit unit, the heater circuit unit including a heater that heats a barrel of an injection molding machine, and a solid state relay that switches on / off power supply to the heater, the main breaker including a leakage current detector that can detect leakage current in the heater circuit unit, the main breaker being configured to operate when a predetermined leakage current detection time has elapsed since the leakage current detector detected the leakage current, The control unit executes a main breaker operation avoidance control for controlling the solid state relay so as to temporarily turn off the power supply before the leakage current detection time has elapsed. A heating control program comprising:

Images