Heating control method and heating control apparatus for injection molding machine

Abstract

To enable an injection molding machine to be installed as it is without replacing heating means such as a band heater even when a power supply voltage of a power source is different.SOLUTION: There is provided a heating control method for an injection molding machine, which is configured in that: heating means 2 which is adaptable to an electric energy which permits a power source voltage expected at an arbitrary place of use is selected and is attached to an injection molding machine M in advance; when the injection molding machine M is installed at the place of use, a power source voltage of a power source Po is obtained, as an actual power source voltage Vp, directly or indirectly by a molding machine controller 3 provided in the injection molding machine M; an energization gradient ratio Rc based on a ratio of the actual power source voltage Vp to a rated voltage Vs of the heating means 2 provided in the injection molding machine M is calculated as a conversion factor Kc; and supply power Pu to the heating means 2 is controlled by power distribution processing of multiplying a controlled variable Cs associated with the heating means 2 by the conversion factor Kc.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heating control method and apparatus for an injection molding machine, which are suitable for use when adapting a power supply that supplies power to the injection molding machine to the injection molding machine.

Background Art

[0002] Generally, injection molding machines are installed and used in molding factories and the like in various regions around the world, including in Japan. In this case, the voltage of the power supply that supplies power to the injection molding machine varies depending on the power supply standard in the region, and a voltage in the range of approximately 200V - 480V is generally used. Therefore, when manufacturing an injection molding machine, it is designed to be compatible with the voltage of the installation region. Specifically, the rated voltage of the band heater (heating means) attached to the heating cylinder is selected to avoid problems such as mismatches with the installation region at the time of factory shipment. However, in reality, there are quite a few cases where the power supply voltage is different when actually installed due to the usage environment and the like. Eventually, in this case, it is necessary to replace the heating means (band heater) attached to the injection molding machine, resulting in wasted installation time and unnecessary costs.

[0003] On the other hand, on the injection molding machine side as well, countermeasures have been proposed to enable it to cope with different power supply voltages without replacing the heating means. The applicant has already proposed a temperature control method for an injection molding machine that can cope with this problem in Patent Document 1.

[0004] When producing molded products (products) using an injection molding machine, in many cases, multi-variety and small-lot production is carried out, and production switching needs to be frequently implemented. That is, it is necessary to frequently switch molding conditions such as the heating temperature of the mold. Therefore, this temperature control method is aimed at addressing this issue. Specifically, it is a temperature control method for an injection molding machine in which a heating means or a cooling means is attached to a temperature control target part to be temperature-controlled for heating or cooling, and the heating means or the cooling means is controlled so that the temperature of the temperature control target part reaches a preset target temperature. The warm-up temperature control ability and the molding temperature control ability are set by the supply power supplied to the heating means or the cooling means. When switching from the warm-up temperature control ability to the molding temperature control ability, the supply power is distributed by a power distribution process, and as the power distribution process, it is performed by a waveform thinning process that thins out a part of the AC waveform.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the other hand, the temperature control method of the injection molding machine in the above-mentioned Patent Document 1 also had the following problems to be solved.

[0007] That is, each temperature control ability is set by the power supplied to the heating means, and the switching of each temperature control ability is performed by a power distribution process that distributes the supplied power. Specifically, it is a power distribution process by a waveform thinning process that thins out a part of the AC waveform. Therefore, it is an advantage of the power distribution process that each temperature control ability can be easily generated (selected), and without using large-scale voltage conversion means or current conversion means, the control and implementation can be facilitated, and further, the miniaturization of the device can be achieved.

[0008] However, there has been a long-standing need for improvement measures to effectively address the issues that arise when the injection molding machine is transported (delivered) to various regions, namely, the power supply for the injection molding machine, which cannot handle different external power supply voltages.

[0009] An object of the present invention is to provide a heating control method and apparatus for an injection molding machine that solve the problems existing in such background art.

Means for Solving the Problems

[0010] The heating control method for an injection molding machine according to the present invention, in order to solve the above-described problems, when adapting the injection molding machine M to the power supply Po that supplies power to the injection molding machine M, first, a heating means 2 that can be adapted to the power amount allowing the power supply voltage assumed at any place of use is selected in advance and assembled to the injection molding machine M. When installing the injection molding machine M at the place of use, the molding machine controller 3 provided in the injection molding machine M directly or indirectly acquires the power supply voltage at the power supply Po as the actual power supply voltage Vp, calculates a conduction gradient ratio Rc based on the ratio of the actual power supply voltage Vp to the rated voltage Vs of the heating means 2 provided in the injection molding machine M as a conversion coefficient Kc, and controls the supply power Pu to the heating means 2 by a power distribution process of multiplying the conversion coefficient Kc by the control amount Cs for the heating means 2.

[0011] In addition, in order to solve the above-described problems, when configuring the heating control device 1 of the injection molding machine according to the present invention to be a heating control device that adapts the injection molding machine M to the power supply Po that supplies power to the injection molding machine M, the heating means 2 assembled to the injection molding machine M is selected to be adaptable to the power amount that allows the power supply voltage assumed at any place of use, the actual power supply voltage acquisition functional unit Fd that directly or indirectly acquires and processes the power supply voltage in the power supply Po as the actual power supply voltage Vp, the conversion coefficient calculation functional unit Fc that calculates and processes the energization gradient rate Rc based on the ratio of the actual power supply voltage Vp and the rated voltage Vs of the heating means 2 provided in the injection molding machine M as the conversion coefficient Kc, and the power distribution processing unit Fpd that controls the supply power Pu to the heating means 2 by multiplying the conversion coefficient Kc by the control amount Cs for the heating means 2. The molding machine controller 3 having the supply power control function unit Fp including the above is provided.

[0012] On the other hand, according to a preferred aspect of the present invention, when implementing the heating control method, the actual power supply voltage Vp can be indirectly acquired from the DC voltage Ed in the drive circuit 12 that drives the actuators 11a... built in the injection molding machine M. Further, the power distribution process can be performed by a waveform thinning process that thins out a part of the AC waveform W based on the conversion coefficient Kc, and this waveform thinning process can be performed by multiplying the control amount Cs by the energization gradient rate Rc. Furthermore, the control amount Cs can be applied to the control amount MV in the PID control system C in which a predetermined PID constant is set. On the other hand, when implementing the heating control device 1, the molding machine controller 3 can be provided with at least a display 13 that displays on the screen one or more of the actual power supply voltage Vp, the rated voltage Vs, and the energization gradient rate Rc, and the molding machine controller 3 can be provided with an output limiter 14 that limits the conversion coefficient Kc so as not to exceed 100%. Furthermore, the heating means 2 can include one or more band heaters 15n...

Effects of the Invention

[0013] According to the heating control method and device 1 of the injection molding machine M according to the present invention as described above, the following remarkable effects are achieved.

[0014] (1) In order to use the power distribution function that distributes and outputs power through power distribution processing, the advantages of power distribution processing, that is, without using large-scale voltage transformation means or current transformation means, it is possible to facilitate control and implementation, and further reduce the size of the device. In particular, when the injection molding machine M is carried into (installed in) an area with various power supply voltages, even when the power supply Po, the power supply voltage, and the rated voltage Vs of the heating means 2 provided in the injection molding machine M do not match, the injection molding machine M can be installed as it is without replacing the heating means 2 such as a band heater. Thus, problems such as wasting useless installation time and generating unnecessary costs can be avoided. Moreover, by selecting one type of heating means having an appropriate power capacity, the injection molding machines manufactured in advance can be stocked, and secondary effects such as increasing the degrees of freedom in design and production can also be enjoyed.

[0015] (2) According to a preferred embodiment, when implementing the heating control method, if the actual power supply voltage Vp is indirectly obtained and processed from the DC voltage Ed in the drive circuit 12 that drives the actuators 11a... built in the injection molding machine M, it can be implemented without adding separate voltage detection means, thus contributing to cost reduction and miniaturization.

[0016] (3) According to a preferred embodiment, if the power distribution processing is performed by a waveform thinning process that thins out a part of the AC waveform W based on the conversion coefficient Kc, the AC waveform W can be variable (distributed) by time-division processing, so that it can be easily implemented without involving complication and enlargement of the control system.

[0017] (4) According to a preferred embodiment, as the control quantity Cs, if the control quantity MV in the PID control system C with a predetermined PID constant set is used, since the PID control system C for the temperature during molding is utilized, stable and reliable control can be performed.

[0018] (5) In a preferred embodiment, when implementing the heating control device 1, if the molding machine controller 3 is provided with a display 13 that displays, on the screen, at least one or more of the actual power supply voltage Vp, rated voltage Vs, and energization gradient rate Rc, the operator can visually confirm the actually acquired actual power supply voltage Vp, rated voltage Vs, and the calculated energization gradient rate Rc. Therefore, it is possible to easily and surely grasp whether an appropriate voltage (power) is being supplied and appropriate control is being performed.

[0019] (6) In a preferred embodiment, when implementing the heating control device 1, if the molding machine controller 3 is provided with an output limiter 14 that restricts the conversion coefficient Kc so that it does not exceed 100%, generation of excessive power can be particularly avoided. Thus, disconnection of the heater and the like can be avoided, protection of the injection molding machine M can be achieved, and further improvement in safety and reliability can also be contributed to.

[0020] (7) In a preferred embodiment, if the heating means 2 includes one or more band heaters 15n..., it can be used for heating control of the heating cylinder, which is the most important heating part in the injection molding machine M. Therefore, it can contribute to the stabilization of the operation of the injection molding machine M and further improvement in molding quality.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0022] Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

[0023] First, the configuration of the injection molding machine M capable of implementing the heating control method according to the present embodiment will be described with reference to FIG. 2 (FIGS. 3, 8, and 9).

[0024] FIG. 2 shows the injection molding machine M, particularly the injection device Mi with the mold (mold clamping device) omitted, and also shows the drive control system Ms for driving and controlling various actuators of this injection molding machine M.

[0025] In the injection device Mi, 21 is a heating cylinder, and an injection nozzle 21n is provided at the front end of this heating cylinder 21 via a head portion 21e. Further, a hopper 21h for storing a molding material (resin material) 21r is provided at the rear end of the heating cylinder 21, and the lower end opening of this hopper 21h and the inside of the heating cylinder 21 communicate with each other via a material dropping passage.

[0026] As a result, the molding material 21r in the hopper 21h is supplied into the heating cylinder 21 through the material dropping passage. Further, a screw 22 is loaded rotatably and axially movably inside the heating cylinder 21, and the rear end portion of the screw 22 is coupled to the screw drive unit 23. The screw drive unit 23 includes a screw rotation mechanism 23r for rotating the screw 22 and a screw axial movement mechanism 23m for moving the screw 22 forward or backward. In the exemplary case, the drive methods of the screw rotation mechanism 23r and the screw axial movement mechanism 23m are electric drive methods using electric motors. The drive method may be a hydraulic drive method using a hydraulic circuit or the like, and the drive method is not limited.

[0027] On the other hand, the screw rotation mechanism 23r and the screw axial movement mechanism 23m are connected to a controller main body 26 provided in the molding machine controller 3. As a result, a control command for driving and controlling the screw rotation mechanism 23r and the screw axial movement mechanism 23m is given from the controller main body 26, and physical quantities such as the speed and position of the screw 22 are detected by a speed sensor, a position sensor, etc. (not shown), and this detection signal is given to the controller main body 26.

[0028] Furthermore, the heating cylinder 21 has a heating cylinder front portion, a heating cylinder middle portion, a first heating cylinder rear portion, and a second heating cylinder rear portion from the front side to the rear side, and a front heating portion 2f, a middle heating portion 2m, a first rear heating portion 2ra, and a second rear heating portion 2rb constituting the heating means 2 are respectively attached to the outer peripheral surfaces of the respective portions. Similarly, a nozzle heating portion 2n is attached to the outer peripheral surface of the injection nozzle 21n. These heating portions 2f, 2m, 2ra, 2rb, 2n are constituted by band heaters 15f, 15m, 15ra, 15rb, 15n, are connected to a heater driver 28, and this heater driver 28 is connected to the controller main body 26. Fig. 3 shows a front configuration diagram of the front heating portion 2f. Further, the heater driver 28 is constituted by a PID control system C shown in Fig. 9 and constitutes a main part of the heating control device 1 according to the present embodiment described later.

[0029] Accordingly, a control command for each of the heating units 2f…2n is given from the controller main body 26 to the heater driver 28, and the heating temperature is detected by a temperature sensor (such as a thermocouple), not shown in the figure. This detection signal is given to the heater driver 28 and the controller main body 26.

[0030] Also, reference numeral 3 denotes a molding machine controller that controls the overall operation of the injection molding machine M, and includes the above-described controller main body 26 having a computer function incorporating hardware such as a CPU and an internal memory 3m. The internal memory 3m includes a data area 3md in which various types of data including a database can be written, and a program area 3mp that stores a comprehensive control program (software) for executing various arithmetic processes and various control processes (sequence control). Therefore, the molding machine controller 3 includes an HMI control system and a PLC control system, and the internal memory 3m stores a PLC program and an HMI program. By the PLC program, sequence operations of various processes in the injection molding machine M and monitoring of the injection molding machine M are executed, and by the HMI program, setting and display of operation parameters of the injection molding machine M, display of operation monitoring data of the injection molding machine M, and the like are executed.

[0031] Furthermore, a display 13 is attached to the molding machine controller 3. The display 13 can display necessary information, and in particular, can display the basic setting screen 41 shown in FIG. 8 in the heating control device 1 according to the present embodiment. Also, a touch panel 13t is provided, and various input operations such as input, setting, and selection can be performed using this touch panel 13t. The molding machine controller 3, the heater driver 28, and the like constitute a drive control system Ms in the injection molding machine M.

[0032] Next, the heating control device 1 that constitutes the main part of the present invention will be specifically described with reference to FIGS. 2 to 9.

[0033] As a basic function, the heating control device 1 has a function of adapting the injection molding machine M to a power supply Po that supplies power to the injection molding machine M.

[0034] Therefore, as a basic configuration, the heating means 2 assembled to the injection molding machine M is selected to be adaptable to the amount of electric power that allows the power supply voltage assumed at any place of use, and the actual power supply voltage acquisition functional unit Fd that directly or indirectly acquires and processes the power supply voltage in the power supply Po as the actual power supply voltage Vp, the conversion coefficient calculation functional unit Fc that calculates the energization gradient rate Rc based on the ratio between the actual power supply voltage Vp and the rated voltage Vs of the heating means 2 provided in the injection molding machine M as the conversion coefficient Kc, and the power distribution processing unit Fpd that controls the supply power Pu to the heating means 2 by multiplying the conversion coefficient Kc by the control amount Cs for the heating means 2, and a molding machine controller 3 including a supply power control functional unit Fp having the above are provided.

[0035] The heating means 2 includes the front heating part 2f, the middle heating part 2m, the first rear heating part 2ra, and the second rear heating part 2rb attached to the heating cylinder 21 described above, and also includes the nozzle heating part 2n. In this case, as described above, for each heating part 2f..., the band heater 15f... is used (see FIG. 3). In this way, if one or two or more band heaters 15n... are included in the heating means 2, it can be used for heating control of the heating cylinder, which is the most important heating part in the injection molding machine M, and thus can contribute to the operation stabilization of the injection molding machine M and further to the improvement of the molding quality.

[0036] By the way, conventionally, when selecting this band heater 15f..., a band heater having a rated voltage Vs corresponding to the power supply Po has been selected. For example, when the power supply Po is a three-phase AC power supply of 200 [V], a band heater having a rated voltage Vs matching this 200 [V] is selected.

[0037] However, in the heating control device 1 according to the present embodiment, a band heater 15f... that is adaptable to the amount of electric power that allows the power supply voltage assumed at any place of use is selected.

[0038] The selection reasons and verification results will be described below. In many cases, the power supply voltages assumed for any usage location are "200 [V]", "220 [V]", "380 [V]", "400 [V]", "420 [V]", "440 [V]", "460 [V]", "480 [V]" (see Figure 4).

[0039] In this case, it can be roughly classified into the 200 [V] class and the 400 [V] class. Therefore, on the injection molding machine side, for example, in the case of the band heater 15f shown in Figure 3, a pair of band heaters 15fp and 15fq curved in a semi-circular shape are circularly mounted on the outer peripheral surface of the heating cylinder 21. When used as the 400 [V] class, as shown by the dotted line Ls, the terminal 36a and the terminal 36b are connected in series, and a voltage is applied between the terminal 37a and the terminal 37b. Also, when used as the 200 [V] class, the terminal 36a and the terminal 36b are connected, and the terminal 37a and the terminal 37b are connected, and a voltage is applied between the terminals 36a and 37a connected in parallel. Note that 35 indicates a fixing band, and 38c indicates a fixture.

[0040] Therefore, the band heater 15f that can be adapted to the amount of power allowed by the power supply voltage can be selected as follows. For example, when using a 1000 [W] band heater with a rated voltage Vs of 380 [V] and the power supply voltage (Vp) is 440 [V], as will be described in detail later, the energization gradient rate Rc is 75 [%] (see Figure 4), and the amount of power equivalent to 1000 [W] can be reduced. Therefore, in this case, it means that even when the band heater 15f with a rated voltage Vs of 380 [V] is selected, it can be tolerated up to 440 [V] as the power supply voltage (Vp). Note that in the case of the example, if it is used at 440 [V] without multiplying the energization gradient rate Rc, an excessive amount of power of 1341 [W] will be supplied, which may lead to heater disconnection.

[0041] In addition, the controller main body 26 is provided with an actual power supply voltage acquisition function unit Fd that directly or indirectly acquires and processes the power supply voltage in the power supply Po as the actual power supply voltage Vp. FIG. 5 shows the internal circuit of the servo driver 31 (FIG. 2) as the actual power supply voltage acquisition function unit Fd used in this embodiment. A converter module 32 is provided in the front stage of the servo driver 31, and inverter modules 33a and 33b are provided in the rear stage.

[0042] In this case, the input side of the converter module 32 is connected to the power supply Po, and the output sides of the inverter modules 33a and 33b are connected to the actuators 11a and 11b using electric motors. These actuators 11a and 11b respectively constitute the screw rotation mechanism 23r and the screw advance / retreat mechanism 23m described above. Therefore, the servo driver 31 constitutes a drive circuit 12 that drives the actuators 11a... built in the injection molding machine M.

[0043] In the exemplary case, the power supply voltage (measured value) of the power supply Po is a three-phase AC voltage of 202 [V], and the DC voltage Ed that appears between the output parts 32p and 32n of the converter module 32 is 287 [V]. This DC voltage Ed functions as the actual power supply voltage acquisition function unit Fd given to the controller main body 26. Thus, since the actual power supply voltage acquisition function unit Fd according to this embodiment has a function of indirectly acquiring and processing from the DC voltage Ed as the actual power supply voltage Vp, it can be implemented without adding separate voltage detection means, contributing to cost reduction and miniaturization.

[0044] Then, this three-phase AC voltage 202 [V] and the DC voltage Ed (287 [V]) are displayed on the screen of the display 13. FIG. 9 shows the basic setting screen 41 displayed on the display 13. In the basic setting screen 41, the range surrounded by the virtual line indicates the additional display section 41p added by the current heating control device 1. 42 indicates the input AC voltage display section that displays the three-phase AC voltage 202 [V], and 43 becomes the output DC voltage display section that displays the DC voltage Ed (287 [V]). Also, 44 is the display section of the rated voltage Vs, and it shows the voltage display sections 44f, 44m, 44ra, 44rb, 44n that display the rated voltage Vs set for each of the above-described heating sections 2f, 2m, 2ra, 2rb, 2n. 45 is the display section of the gradient rate corresponding to each voltage Vs, and it includes the gradient rate display sections 45f, 45m, 45ra, 45rb, 45n corresponding to each rated voltage Vs.

[0045] In this way, if the molding machine controller 3 is provided with at least the display 13 that displays on the screen at least one or more of the actual power supply voltage Vp, the rated voltage Vs, and the energization gradient rate Rc, the operator can visually confirm the actually obtained actual power supply voltage Vp, the rated voltage Vs, and the calculated energization gradient rate Rc. Therefore, it is possible to easily and surely grasp whether an appropriate voltage (power) is supplied and appropriate control is being performed.

[0046] On the other hand, the controller main body 26 is provided with a conversion coefficient calculation function unit Fc that calculates the energization gradient rate Rc based on the ratio of the actual power supply voltage Vp and the rated voltage Vs in the injection molding machine M as the conversion coefficient Kc.

[0047] Specifically, the actual power supply voltage Vp is calculated from the captured DC voltage Ed by [Calculation Formula 100]. Vp = Ed / √2 [V] … [Calculation Formula 100]

[0048] In the above case, since the DC voltage Ed is 287 [V], the actual power supply voltage Vp is approximately 202 [V], and the power supply voltage of the power supply Po can be obtained by estimation according to [Calculation Formula 100].

[0049] In addition, the energization gradient rate Rc can be obtained by [Calculation Formula 101]. Now, when the rated voltage Vs is 240 [V] and the actual power supply voltage Vp is 202 [V], Rc = (Vp / Vs)^2 × 100 [%] … [Calculation Formula 101] and the energization gradient rate Rc becomes 70.8 [%]. In this way, the energization gradient rate Rc can be calculated based on the actual power supply voltage Vp and the rated voltage Vs. Figure 4 shows a list of the calculated energization gradient rates Rc for the power supply voltages of various power supplies Po described above.

[0050] Also, the display unit 44 for the rated voltage Vs shown in Figure 8 indicates the rated voltage Vs set for each heating unit 2f, 2m, 2ra, 2rb, 2n. In this way, in the injection molding machine M, the amount of power corresponding to the rated voltage Vs used corresponding to the power supply voltage can be set by the energization gradient rate Rc, and the calculated energization gradient rate Rc is displayed corresponding to each rated voltage Vs in the gradient rate display unit 45.

[0051] On the other hand, the obtained energization gradient rate Rc is supplied to the power supply control function unit Fp in the controller main body 26 as a conversion coefficient Kc, and the supply power Pu to the heating means 2 can be controlled by multiplying the control amount Cs for the heating means 2.

[0052] FIG. 9 shows the main circuit of the heater driver 28, and an example shows a PID control system C that serves as a supply power control function unit Fp for the band heater 15f. The PID control system C includes a PID circuit 52 and a power distributor 53. The PID circuit 52 includes a subtraction unit 54 that subtracts a detected temperature PV [°C] from a set temperature (command value) SV [°C] given from the controller main body 26, an integration calculation unit 56 that calculates an integration operation amount based on a deviation e obtained from the subtraction unit 54, a proportional calculation unit 55 that calculates a proportional operation amount based on the deviation e, a differential calculation unit 57 that calculates a differential operation amount based on the deviation e, an addition unit 58 that adds the output operation amounts of the integration calculation unit 56, the proportional calculation unit 55, and the differential calculation unit 57, and an output limiter 14 that limits the output operation amount MVt of the addition unit 58 between an upper limit value and a lower limit value. The output operation amount MV of the output limiter 14 is applied to the power distributor 53. Note that this PID control system C is a general known PID control system.

[0053] In this case, the output limiter 14 can be provided with a function of limiting the conversion coefficient Kc so as not to exceed 100%. By providing such an output limiter 14, generation of excessive power can be particularly avoided, so that heater disconnection and the like can be avoided, the injection molding machine M can be protected, and further improvement in safety and reliability can also be contributed.

[0054] The above-described conversion coefficient Kc is applied to the power distributor 53 that functions as a power distribution processing unit Fpd, and power distribution processing is performed by this power distributor 53. That is, in the power distributor 53, the supply power Pu to the band heater 15f is controlled by a power distribution process of multiplying the conversion coefficient Kc by a control amount Cs (MV) for the band heater 15f (heating means 2).

[0055] The power distribution process is performed by a waveform thinning process that thins out a part of the AC waveform W based on the conversion coefficient Kc. In this way, if the power distribution process is performed by the waveform thinning process that thins out a part of the AC waveform W based on the conversion coefficient Kc, the AC waveform W can be variably (distributed) by time division processing, so that it can be easily implemented without accompanying complication and enlargement of the control system. Further, as the control quantity Cs, if the control quantity MV in the PID control system C in which a predetermined PID constant is set is used, since the PID control system C for the temperature at the time of molding is used, stable and reliable control can be performed.

[0056] Figures 6 and 7 show the AC waveform W distributed by the supply power control function unit Fp including the power distributor 53. The waveform indicated by the dotted line including the solid line is the case where the output distribution is 100 [%]. In the exemplary case, 220 [V] AC power of 50 or 60 [Hz] can be output as it is.

[0057] The waveform thinning process according to FIG. 6 is the case where the energization gradient rate Rc (N%) is multiplied by the control quantity Cs. The supply power Pu has a section of N% where the half wave Wh indicated by the solid line exists and a section where the half wave Wo indicated by the dotted line is thinned out at a ratio of (100 - N)%. Further, the waveform thinning process according to FIG. 7 is the case where the energization gradient rate Rc (Q%) is multiplied by the control quantity Cs. The supply power Pu conducts electricity in the Wf section of Q% indicated by the solid line and stops conducting electricity in the Wo section of (100 - Q)% indicated by the dotted line, that is, it shows a thinned state. This control cycle is approximately 0.5 seconds. In addition, although the start point and the end point in the case of thinning are arbitrary, it is desirable from the viewpoint of suppressing unnecessary noise generation etc. to perform it in the section from the start point 0 [V] point to the end point 0 [V] point.

[0058] Next, the processing procedure of the heating control method according to the present embodiment will be described according to the flowchart shown in FIG. 1 while referring to each figure.

[0059] First, at the manufacturer side, that is, in the manufacturing stage of the injection molding machine M, a band heater 15f that serves as a heating means 2 adaptable to the power amount allowing the power supply voltage assumed at any place of use is selected (step S1). Then, as shown in FIG. 3, the selected band heater 15f is mounted on the outer peripheral surface of the heating cylinder 21, and the entire injection molding machine M is manufactured (step S2). On the other hand, when the injection molding machine M is completed, the rated voltage 220 [V] corresponding to each band heater 15f is set (step S3). FIG. 8 shows, as an example, the rated voltage 220 [V] set for each part of the heating cylinder 21 in the additional display section 41p of the basic setting screen 41.

[0060] In this case, the setting of the rated voltage 220 [V] may be performed at this point in time, or may be performed after being transported to an arbitrary installation area described later. At this point in time, since the specific place of use is not specified, the completed injection molding machine M can be stocked in a predetermined storage warehouse or the like (step S4).

[0061] On the other hand, assume a case where a request for installation of the injection molding machine M is received from a user in an arbitrary region. In this case, a predetermined model ordered by the user is transported from the stocked injection molding machine M to the user's side region and installed in a molding factory or the like (step S11). When the installation of the injection molding machine M is completed, the injection molding machine M is connected to the power supply Po and the power is turned on (step S12).

[0062] As a result, the actual power supply voltage acquisition function unit Fd provided in the controller main body 26 of the heating control device 1 performs the process of taking in the DC voltage Ed between the output parts 32p and 32n of the converter module 31, that is, the actual power supply voltage Vp (step S13). Further, the conversion coefficient calculation function unit Fc provided in the controller main body 26 calculates the energization gradient rate Rc based on the ratio between the actual power supply voltage Vp and the rated voltage Vs in the injection molding machine M (step S14). Then, the obtained energization gradient rate Rc is given as the conversion coefficient Kc to the power distribution processing unit Fpd shown in FIG. 9, that is, the power distributor 53 (step S15). Further, the conversion coefficient Kc is subjected to a display process on the additional display unit 41p shown in FIG. 8 (step S16).

[0063] On the other hand, the power distributor 53 performs a power distribution process of multiplying the conversion coefficient Kc by the control amount Cs (control amount MV) for the heating means 2 to distribute power (step S17). As a result, the power supplied to the band heater 15f, that is, the power supplied with a part of the AC waveform thinned out is output. Although the processing procedure for the band heater 15f has been described, the same processing is performed for the other band heaters 15m, 15ra, 15rb, and 15n.

[0064] Then, when the processing for all the rated voltages Vs is completed, the setting process for the power supply voltage is completed (steps S18 and S19). That is, the basic setting for adapting the injection molding machine M to the power supply voltage in the power supply Po that supplies power to the injection molding machine M is completed.

[0065] As a result, during operation, the power supplied processed by the power distribution processing unit Fpd, that is, the power supplied with a part of the AC waveform thinned out is output to the corresponding band heaters 15f... (step S20).

[0066] Therefore, according to the heating control method and the heating control device 1 of the injection molding machine according to such an embodiment of the present invention, as a basic method, a heating means 2 that can be adapted to the power amount allowing the power supply voltage assumed at an arbitrary use location is selected in advance and assembled to the injection molding machine M. When the injection molding machine M is installed at the use location, the molding machine controller 3 provided in the injection molding machine M directly or indirectly acquires the power supply voltage at the power supply source Po as the actual power supply voltage Vp, and calculates the energization gradient rate Rc based on the ratio of the actual power supply voltage Vp to the rated voltage Vs of the heating means 2 provided in the injection molding machine M as the conversion coefficient Kc. Since the supply power Pu to the heating means 2 is controlled by the power distribution process of multiplying the conversion coefficient Kc by the control amount Cs for the heating means 2, the advantages of the power distribution process, that is, without using large-scale voltage conversion means or current conversion means, the control and implementation can be facilitated, and further, the size of the device can be reduced. In particular, when the injection molding machine M is carried (installed) into an area having various power supply voltages, even when the power supply source Po, the power supply voltage, and the rated voltage Vs of the heating means 2 provided in the injection molding machine M are not compatible, the injection molding machine M can be installed as it is without replacing the heating means 2 such as a band heater. It is possible to avoid problems such as wasteful installation time and unnecessary costs. Moreover, by selecting one type of heating means having an appropriate power capacity, secondary effects such as being able to stock pre-manufactured injection molding machines can be enjoyed, and the degrees of freedom in design and production can be increased.

[0067] As described above, the preferred embodiment has been described in detail. However, the present invention is not limited to such an embodiment, and can be arbitrarily changed, added, or deleted within the scope not departing from the gist of the present invention in terms of the detailed configuration, shape, material, quantity, numerical value, method, etc.

[0068] For example, in the embodiment, when obtaining the power supply voltage at the power supply source Po as the actual power supply voltage Vp, the case of indirectly obtaining it from the DC voltage Ed in the drive circuit 12 is shown, but it may also be directly detected. Further, as the power distribution process, the case of performing thinning processing of a part of the AC waveform W based on the conversion coefficient Kc is shown, but it does not exclude the case of using other known methods for changing the power amount, such as changing the period of the waveform like PWM control. Furthermore, it is desirable to apply the control amount Cs in a PID control system with a predetermined PID constant set, but it does not exclude the case of applying it to the control amounts of other different control systems. On the other hand, the case of displaying at least one or more of the actual power supply voltage Vp, the rated voltage Vs, and the energization gradient rate Rc on the display 13 is exemplified, but it is not an essential component. Also, the output limiter 14 that limits the conversion coefficient Kc so as not to exceed 100% does not exclude the case of limiting by other methods, and various heating methods can be applied to the heating means 2, including the band heater 15n....

Industrial Applicability

[0069] The heating control method and the heating control device 1 according to the present invention can be used when connecting an injection molding machine to a power supply in each region having a different power supply voltage to adapt the injection molding machine.

Explanation of Signs

[0070] 1: Heating control device, 2: Heating means, 3: Molding machine controller, 11a...: Actuator, 12: Drive circuit, 13: Display, 14: Output limiter, 15n...: Band heater, M: Injection molding machine, Po: Power supply, Pu: Supply power, Vp: Actual power supply voltage, Vs: Rated voltage, Rc: Energization gradient rate, Kc: Conversion coefficient, Cs: Control amount, MV: Control amount, Fd: Actual power supply voltage acquisition functional unit, Fc: Conversion coefficient calculation functional unit, Fpd: Power distribution processing unit, Fp: Supply power control functional unit, Ed: DC voltage, W: AC waveform, Wh: Half wave, Wf: Full wave

Claims

1. A heating control method for an injection molding machine that adapts the injection molding machine to a power supply that supplies power to the injection molding machine. The method includes: selecting in advance a heating means adaptable to an electric power amount that allows a power supply voltage assumed at an arbitrary use location, and assembling the heating means to the injection molding machine; when installing the injection molding machine at the use location, directly or indirectly obtaining and processing the power supply voltage in the power supply source as an actual power supply voltage by a molding machine controller provided in the injection molding machine; calculating and processing a conduction gradient ratio based on a ratio between the actual power supply voltage and a rated voltage of the heating means provided in the injection molding machine as a conversion coefficient; and controlling the supply power to the heating means by a power distribution process of multiplying the conversion coefficient by a control amount for the heating means. A heating control method for an injection molding machine is characterized by the above.

2. The heating control method for an injection molding machine according to claim 1, wherein the actual power supply voltage is indirectly obtained and processed from a DC voltage in a drive circuit that drives an actuator built in the injection molding machine.

3. The heating control method for an injection molding machine according to claim 1, wherein the power distribution process is performed by a waveform thinning process of thinning out a part of an AC waveform based on the conversion coefficient.

4. The heating control method for an injection molding machine according to claim 3, wherein the waveform thinning process is performed by multiplying the conduction gradient ratio by the control amount.

5. The heating control method for an injection molding machine according to claim 1, wherein the control amount is applied as a control amount in a PID control system in which predetermined PID constants are set.

6. The heating control method for an injection molding machine according to claim 1, wherein the heating means includes one or two or more band heaters.

7. A heating control device for an injection molding machine that adapts the injection molding machine to a power supply that supplies power to the injection molding machine, comprising: a heating means assembled to the injection molding machine by selectively selecting to be compatible with an electric power amount that allows a power supply voltage assumed at an arbitrary usage location; an actual power supply voltage acquisition functional unit that directly or indirectly acquires and processes the power supply voltage in the power supply as an actual power supply voltage; a conversion coefficient calculation functional unit that calculates a conduction gradient rate based on a ratio of the actual power supply voltage to a rated voltage of the heating means provided in the injection molding machine as a conversion coefficient; and a supply power control functional unit having a power distribution processing function that controls the supply power to the heating means by multiplying the conversion coefficient by a control amount for the heating means. The heating control device for an injection molding machine is characterized by comprising a molding machine controller.

8. The heating control device for an injection molding machine according to claim 6, wherein the actual power supply voltage is indirectly acquired from a DC voltage in a drive circuit that drives an actuator built in the injection molding machine.

9. The heating control device for an injection molding machine according to claim 6, wherein the heating means includes one or two or more band heaters.

10. The heating control device for an injection molding machine according to claim 6, wherein the molding machine controller includes at least a display that displays on a screen one or two or more of the actual power supply voltage, the rated voltage, and the conduction gradient rate.

11. The heating control device for an injection molding machine according to claim 6, wherein the molding machine controller includes an output limiter that limits the conversion coefficient so as not to exceed 100%.

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