Control device and program for injection molding machine

Abstract

Provided is a control device and program for an injection molding machine that can quantitatively obtain a factor of temperature variation. The control device includes an operation information acquisition section that acquires operation information; a characteristic information acquisition section that acquires characteristic information related to the characteristics of heat emission from a heater; a surface temperature acquisition section that acquires the surface temperature of the heater over a prescribed period included in the acquired operation information; a performance information acquisition section that acquires the performance of the ratio of the surface temperature of the heater to a set temperature with respect to the progress of the heater output of the heater as performance information; an estimation section that estimates the surface temperature of the heater at a prescribed time based on the operation information, the performance information, and the acquired surface temperature; and an energy calculation section that calculates the amount of heat emission from the surface of the heater to the environment based on the characteristic information and the estimated surface temperature, and at least calculates the heat transfer energy transferred from the heater to the resin and the shear energy generated by the screw.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control device and a program of an injection molding machine. BACKGROUND

[0002] In the past, an injection molding machine that melts pellets (resin) added to a hopper in a cylinder and injects the pellets into a mold has been known. A heater is arranged on the outer periphery of the cylinder of the injection molding machine. The cylinder is heated by the heater to melt the pellets.

[0003] Monitoring the relationship between the temperature change and the heat applied to the injection molding machine is useful for monitoring the molding state and rationalizing the condition setting. Therefore, for example, an injection molding machine that measures in advance the correspondence relationship between the heat generated only by the heater and the temperature of the heated cylinder and calculates the difference between the cylinder temperature in actual molding and the cylinder temperature in the measured correspondence relationship as the temperature change due to shear heat generation has been proposed (for example, refer to Patent Literature 1).

[0004] PRIOR ART DOCUMENT

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2001-225372 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In addition, in the injection molding machine, the pellets dropped from the hopper port are melted by heat transfer from the heater and shear heat generation by rotation of the screw. In general, "heat transfer" has a characteristic that the heat supply capacity is low but the deviation is small. In addition, "shear" has a characteristic that the heat supply capacity is high but the deviation is large. The ratio of "heat transfer" to "shear" is preferably optimally distributed according to the requirements for the molded product. In this regard, the ease of appropriately setting the molding conditions becomes high with the increase in the kind of the pellets and the complication of the shape of the molded product. Therefore, the judgment of the rationality of the molding conditions is mostly implemented based on the experience and intuition of skilled technicians. In Patent Literature 1, only the temperature change of the shear is calculated. Therefore, in Patent Literature 1, it is difficult to grasp whether the temperature change at the time of condition change is caused by the condition change. In the condition change, it is preferable to be able to quantitatively obtain the cause of the temperature change.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] (1) The present disclosure relates to a control device of an injection molding machine having a cylinder, a heater disposed around the cylinder, and a screw disposed inside the cylinder, the control device of the injection molding machine being configured to calculate an energy transferred from the heater to a resin at a prescribed time, the control device of the injection molding machine comprising: an operation information acquisition section that acquires operation information including a heater output of the heater, a set temperature of the heater, and a rotational speed of the screw for a prescribed period immediately before the prescribed time; a characteristic information acquisition section that acquires characteristic information regarding a characteristic of heat radiation of the heater; a surface temperature acquisition section that acquires a surface temperature of the heater for the prescribed period included in the acquired operation information; an achievement information acquisition section that acquires an achievement of a change in a ratio of the surface temperature to the set temperature of the heater with respect to a change in the heater output of the heater as achievement information; an estimation section that estimates the surface temperature of the heater at the prescribed time based on the operation information, the achievement information, and the acquired surface temperature; and an energy calculation section that calculates an amount of heat radiation from a surface of the heater to an environment based on the characteristic information, the operation information, and the estimated surface temperature, and at least calculates a heat transfer energy transferred from the heater to the resin and a shear energy generated by the screw.

[0011] (2) In addition, the present disclosure relates to a program that causes a computer to function as a control device of an injection molding machine having a cylinder, a heater disposed around the cylinder, and a screw disposed inside the cylinder, the control device of the injection molding machine being configured to calculate an energy transferred from the heater to a resin, the program causing the computer to function as: an operation information acquisition section that acquires operation information including a heater output of the heater, a set temperature of the heater, and a rotational speed of the screw for a prescribed period immediately before the prescribed time; a characteristic information acquisition section that acquires characteristic information regarding a characteristic of heat radiation of the heater; a surface temperature acquisition section that acquires a surface temperature of the heater for the prescribed period included in the acquired operation information; an achievement information acquisition section that acquires an achievement of a change in a ratio of the surface temperature to the set temperature of the heater with respect to a change in the heater output of the heater as achievement information; an estimation section that estimates the surface temperature of the heater at the prescribed time based on the operation information, the achievement information, and the acquired surface temperature; and an energy calculation section that calculates an amount of heat radiation from a surface of the heater to an environment based on the characteristic information, the operation information, and the estimated surface temperature, and at least calculates a heat transfer energy transferred from the heater to the resin and a shear energy generated by the screw.

[0012] Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a control device and a program of an injection molding machine capable of quantitatively obtaining a factor of temperature change. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram illustrating an injection molding machine including a control device according to an embodiment of the present disclosure.

[0015] Figure 2 is a table illustrating an example of performance information learned by the control device according to an embodiment.

[0016] Figure 3 is a schematic diagram illustrating a relationship among heat generation amount, heat release amount, and heat applied to a pellet generated by a heater and a screw of the injection molding machine according to an embodiment.

[0017] Figure 4 is a block diagram illustrating a structure of the control device according to an embodiment.

[0018] Figure 5 is a schematic diagram illustrating an example of action information of the control device according to an embodiment.

[0019] Figure 6 is a schematic diagram illustrating an example of performance information of the control device according to an embodiment.

[0020] Figure 7 is a screen diagram illustrating a screen displayed on a display portion of the control device according to an embodiment.

[0021] Figure 8 is a flowchart illustrating a flow of an action of the control device according to an embodiment.

[0022] Figure 9 is a screen diagram illustrating a screen displayed on a display portion according to the control device according to a modification.

[0023] Figure 10 is a screen diagram illustrating a screen displayed on a display portion of the control device according to another modification.

[0024] Figure 11 is a screen diagram illustrating a screen displayed on a display portion of the control device according to another modification.

[0025] Figure 12 is a screen diagram illustrating a screen displayed on a display portion of the control device according to another modification. DETAILED DESCRIPTION

[0026] Hereinafter, the present disclosure will be described with reference to the drawings. Figures 1 to 8The control device 1 and the program of the injection molding machine 10 according to one embodiment of the present disclosure will be described.

[0027] First, the injection molding machine 10 controlled by the control device 1 according to the present embodiment will be described.

[0028] The injection molding machine 10 is a device that performs molding by injecting a molten pellet into a mold (not shown). As shown in FIG. 1, the injection molding machine 10 includes, for example, a cylinder 101, a heater 102, and a safety cover 103. Figure 1

[0029] The cylinder 101 is, for example, a cylindrical body. One end of the cylinder 101 in the axial direction is tapered toward the end. The inside of the cylinder 101 has a screw (not shown) along the axial direction. The screw moves the molten pellet toward the one end side of the cylinder 101 while stirring the molten pellet.

[0030] The heater 102 is disposed around the cylinder 101. For example, a plurality of heaters 102 are disposed along the axial direction of the cylinder 101. In the present embodiment, three heaters 102 are disposed along the axial direction, and each heater 102 is disposed so as to cover the outer periphery of the cylinder 101. The heater 102 heats the cylinder 101 to, for example, 200 degrees or higher.

[0031] The safety cover 103 is a concave body disposed around the heater 102. The safety cover 103 is disposed to avoid contact with the heater 102, which is at a high temperature.

[0032] According to the above injection molding machine 10, the pellet is molten in the inside of the cylinder 101 heated by the heater 102 to 200 degrees or higher. The screw injects the molten pellet from the one end of the cylinder 101 into the mold. Thus, the injection molding machine 10 performs, for example, molding of a plastic product.

[0033] Here, the safety cover 103 is disposed around the heater 102, and thus the surface temperature of the heater 102 is not easily measured directly from the outside. On the other hand, it is known that there is a correlation between the actual surface temperature of the heater 102, the set temperature set to the heater 102, and the heater output of the heater 102. Specifically, it is known that there is a correlation between the ratio of the surface temperature of the heater 102 to the set temperature and the average heater output of the heater 102. For example, as shown in FIG. 2, the surface temperature of the heater 102 is correlated with the average heater output of the heater 102. Figure 2 ​The set temperature of the heater 102 and the rotation speed of the screw were set to (1) 220 degrees, 50 rpm; (2) 180 degrees, 100 rpm; and (3) 180 degrees, 50 rpm. As a result, the surface temperature / set temperature was 1.19, 0.792, and 0.919, and the average heater output was 46.6%, 6.62%, and 14.5%, respectively. As a result, the correlation coefficient of the surface temperature / set temperature and the heater output was 0.991. Thus, it was found that there was a strong correlation between the surface temperature / set temperature and the heater output. Furthermore, in the following embodiments, the heater output will be described as an instruction value from a controller (not shown) that controls the heater 102, which indicates the amount of operation of the heater 102. In addition, as an example, the controller determines the instruction value based on the detected value of the temperature control point.

[0034] In addition, as shown in FIG. 2, the heat generation amount E Figure 3 of the heater 102 can be expressed by the sum of the heat release amount E Hi by convection, the heat release amount E Ci by radiation, the heat amount E Ri taken away by the cooling water, the heat transfer amount E0 W to the mechanical body (hopper side), the heat amount E M received by the resin, and the shear energy E S . Here, i (i = 1, 2,..., k) is a natural number indicating a number for identifying the k heaters 102. For example, the heat release amount (heat release by convection + heat release by radiation) to the environment can be expressed by the following equation 1.

[0035] [Equation 1]

[0036]

[0037] The control device 1 of the injection molding machine 10 according to the embodiment below uses the above-described correlation to estimate the surface temperature of the heater 102 from the outside. Thus, the control device 1 of the injection molding machine 10 according to the embodiment below can estimate the surface temperature of the heater 102 with higher precision than when the surface temperature of the heater 102 is estimated using an equation from a temperature control point and a detection point of an additional sensor or the like. Also, the control device 1 of the injection molding machine 10 according to the embodiment below calculates the energy transferred from the heater 102 to the resin. The control device 1 of the injection molding machine 10, for example, calculates the heat transfer energy generated by the heater 102 and the shear energy generated by the screw. In addition, the control device 1 of the injection molding machine according to the embodiment below calculates the ratio of the heat transfer energy to the shear energy. Thus, the control device 1 of the injection molding machine according to the embodiment below can quantitatively obtain the change in energy when the operation condition is changed. Furthermore, in the embodiment below, "during operation" refers to the instant at which the injection molding machine 10 is currently operating. In addition, in the embodiment below, "predetermined timing" refers to the timing at which the surface temperature of the heater 102 is estimated.

[0038] Next, the control device 1 of the injection molding machine 10 according to one embodiment of the present disclosure will be described with reference to Figures 1 to 8

[0039] The control device 1 is a device that controls the injection molding machine 10. Specifically, the control device 1 is a device that controls the molding conditions of the injection molding machine 10. As shown in Figure 1 , the control device 1 is connected to the injection molding machine 10, for example. The control device 1 specifies and controls the molding conditions of the injection molding, such as the speed, pressure, temperature of the cylinder 101, mold temperature, and injection amount of the molten pellets. As shown in Figure 4 , the control device 1 includes an operation information storage section 11, an operation information acquisition section 12, a characteristic information storage section 20, a characteristic information acquisition section 21, a performance information storage section 13, a performance information acquisition section 14, a surface temperature acquisition section 15, a calculation section 16, an estimation section 17, an energy calculation section 22, an output section 18, and an output control section 19.

[0040] The operation information storage section 11 is a recording medium such as a hard disk, for example. The operation information storage section 11 stores operation information related to the set temperature of the heater 102 of the injection molding machine 10 and the heater output of the heater 102 during operation. In addition, the operation information storage section 11 stores the content of the instruction related to the operation of the injection molding machine 10 as operation information, for example. As shown in Figure 5 ​As shown, the operation information storage section 11, for example, sets 0 at the start of the operation and T at the prescribed time, and stores the heater outputs yO, yl,... yT-1 every sampling period t l (s) until t_T-1 immediately before the prescribed time. In addition, the operation information storage section 11 stores S (°C) as the set temperature. In addition, the operation information storage section 11 stores the above molding conditions as the operation information. The operation information storage section 11, for example, stores the screw rotation amount per unit time, the load current rate at the time of molding, the room temperature, the flow rate of the cooling water, the cooling water outlet temperature, and the cooling water inlet temperature as the operation information.

[0041] The operation information acquisition section 12 is realized by, for example, the CPU operating. The operation information acquisition section 12 acquires the heater output of the heater 102 and the set temperature of the heater 102 in the prescribed period immediately before the prescribed time as the operation information. In the present embodiment, the operation information acquisition section 12 acquires the operation information from the operation information storage section 11. The operation information acquisition section 12, for example, acquires the heater output of the heater 102 and the set temperature of the heater 102 in the period from the start of the operation of the injection molding machine 10 until immediately before the prescribed time as the operation information. The operation information acquisition section 12, for example, acquires the heater output expressed in a predetermined sampling period until immediately before the prescribed time. In addition, the operation information acquisition section 12 acquires the rotation speed of the screw, that is, the screw rotation amount, the load current rate, the room temperature, the flow rate, the cooling water outlet temperature, and the cooling water inlet temperature as the operation information.

[0042] The characteristic information storage section 20 is, for example, a recording medium such as a hard disk. The characteristic information storage section 20 stores the characteristic information relating to the characteristic of the heat release of the heater 102. The characteristic information storage section 20 stores the information unique to the heater 102 as the characteristic information. The characteristic information storage section 20, for example, stores the motor torque including the mechanical efficiency and the reduction ratio, the load current rate at the time of idling, the heater capacity, the surface area of the heater 102, the emissivity, the Stefan-Boltzmann coefficient, the density of water, and the specific heat of water as the characteristic information.

[0043] The characteristic information acquisition section 21 is realized by, for example, the CPU operating. The characteristic information acquisition section 21 acquires the characteristic information relating to the characteristic of the heat release of the heater 102.

[0044] The performance information storage section 13 is, for example, a recording medium such as a hard disk. The performance information storage section 13 stores, as performance information, the performance of the ratio of the surface temperature of the heater 102 to the set temperature with respect to the progress of the heater output of the heater 102. The performance information storage section 13, for example, stores, as input data, the progress of the heater output of the heater 102 measured in advance, and stores, as performance information, the progress of the ratio of the surface temperature of the heater 102 to the set temperature of the heater 102 (surface temperature / set temperature) measured at the same time. The performance information storage section 13 stores, as performance information, the performance obtained in advance by learning the teaching data with the heater output as input. The performance information storage section 13, for example, can store, in advance, the performance information obtained by learning the relationship between the heater output and the surface temperature as shown in FIG. 6 using a temperature sensor (not shown) that comes into contact with the surface of the heater 102. The performance information storage section 13, for example, stores a plurality of performances as performance information. As shown in FIG. 7, the performance information storage section 13, for example, stores, for each measured performance, the performance information with the measurement number set to M (M is a natural number), the measurement start time (the operation start time) set to 0, and the time at which the heater output is acquired set to t_N (N is a natural number), the value of the heater output set to x_MN, and the value of the surface temperature / set temperature set to R_MN. Figure 2 Figure 6

[0045] The performance information acquisition section 14 is realized, for example, by the CPU acting. The performance information acquisition section 14 acquires the performance information from the performance information storage section 13. The performance information acquisition section 14, for example, acquires, as performance information, the performance of the ratio of the surface temperature of the heater 102 to the set temperature with respect to the progress of the heater output of the heater 102. Specifically, the performance information acquisition section 14 acquires, as performance information, the ratio of the past set temperature to the past surface temperature (surface temperature / set temperature) for each past heater output.

[0046] The surface temperature acquisition section 15 is realized, for example, by the CPU acting. The surface temperature acquisition section 15 acquires the surface temperature of the heater 102 within the period included in the acquired operation information. The surface temperature acquisition section 15, for example, acquires the surface temperature estimated by the estimation section 17 described later within the period included in the acquired operation information. In addition, the surface temperature acquisition section 15 acquires the surface temperature actually measured or provided from the outside instead of the estimated surface temperature. The surface temperature acquisition section 15, for example, acquires the surface temperature TP_A (°C) (A = 1, 2,... t-1) every sampling period t_1.

[0047] ​​The calculation section 16 is realized by, for example, the CPU acting. The calculation section 16 calculates the progression of the ratio of the surface temperature to the set temperature with respect to the progression of the heater output contained in the action information, based on the acquired action information and the acquired surface temperature. The calculation section 16, for example, calculates the value of the surface temperature / set temperature for each heater output contained in the action information. In the present embodiment, the calculation section 16 calculates (TP_A / S) (A = 1, 2,... t-1) every sampling period t_1.

[0048] The estimation section 17 is realized by, for example, the CPU acting. The estimation section 17 estimates the surface temperature of the heater 102 at a prescribed time, based on the action information, the performance information, and the acquired surface temperature. Specifically, the estimation section 17 uses the performance in the performance information that is similar or identical to the progression of the calculated ratio and the action information to estimate the surface temperature at the prescribed time. The estimation section 17 estimates the surface temperature at the prescribed time from the ratio of the set temperature to the surface temperature at the time corresponding to the prescribed time, as shown by the performance that is similar or identical to the progression. The estimation section 17 determines the performance that is similar or identical to the progression of the heater output and the progression of the ratio of the set temperature to the surface temperature in the action information in the prescribed period immediately before the prescribed time, for example, from the performance information. The estimation section 17 acquires the ratio of the set temperature to the surface temperature at the next time (corresponding to the prescribed time) after the similar or identical period in the determined performance. Then, the estimation section 17 estimates the surface temperature at the prescribed time by multiplying the acquired ratio by the set temperature contained in the action information.

[0049] The energy calculation section 22 is realized by, for example, the CPU acting. The energy calculation section 22 calculates the amount of heat dissipation from the surface of the heater 102 to the environment, based on the characteristic information and the estimated surface temperature. That is, the energy calculation section 22 calculates the sum of the convective heat dissipation and the radiative heat dissipation of the k heaters 102 as the amount of heat dissipation to the environment. Here, the energy calculation section 22 sets the amount of heat dissipation (J) from the heater 102 to the environment as E Ai , sets the amount of convective heat dissipation (J) as E Ci , sets the amount of radiative heat dissipation (J) as E Ri , sets the surface temperature (K) of the heater 102 as T H , sets the room temperature (K) as T R , sets the surface area (m 2 ) of the heater 102 as A i , sets the thermal conductivity (W / m 2 K) as h, sets the emissivity as ε, and sets the Stefan-Boltzmann coefficient (W / m 2 K 4) is set to σ, a number for identifying the k heaters 102 is set to i = 1, 2,... k, and the following number 2 is used to calculate the heat release amount E Ai .

[0050] [number 2]

[0051] E Ai = E Ci + E Ri

[0052]

[0053]

[0054] Further, the energy calculation section 22 can also use a function of the temperature difference between the surface temperature of the heater 102 and the ambient temperature as the thermal conductivity h to calculate E Ai .

[0055] In addition, the energy calculation section 22 calculates at least the heat transfer energy transferred from the heater 102 to the resin (pellets) and the shear energy generated by the screw. The energy calculation section 22 calculates the following number 3 using the heat transfer energy (J) as E S , the motor torque (N m) including the mechanical efficiency and the reduction ratio as T, the screw rotation amount per unit time (rad / s) as R, the load current rate at the time of molding as r M , the load current rate at the time of idling as r M0 , and thereby calculates the work amount of the screw rotation motor as the shear energy E S . The motor torque can be either the rated torque or the maximum torque. The load current rate is an instruction value from a controller for controlling the screw rotation motor, and indicates the ratio of the load torque with respect to the motor torque.

[0056] [number 3]

[0057]

[0058] In addition, the energy calculation section 22 calculates the following number 4 using the heat transfer energy (J) as E T , the heat generation amount of the heater 102 (J) as E Hi , the convective heat release amount (J) from a part of the heater 102 and the cylinder 101 as E Ci ', the radiative heat release amount (J) from a part of the heater 102 and the cylinder 101 as E Ri ', the heat taken away by the cooling water (J) as E W , the heat transfer amount to the hopper side (J) as E0, the capacity (W) of the heater 102 as W i , and the heater output as r i, the convective heat release amount (J) from the region of the unwrapped heater 102 is set as E CNi , the radiative heat release amount (J) from the region of the unwrapped heater 102 is set as E RNi , the density of water (g / cm 3 ) is set as p, the specific heat of water (J / g·K) is set as C W , the flow rate of water (cm 3 / s) is set as Q, the cooling water outlet temperature (K) is set as T OUT , the cooling water inlet temperature (K) is set as T IN The following number 4 is calculated, and thus the heat transfer energy ET is calculated.

[0059] [Number 4]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] In addition, the energy calculation section 22 calculates the ratio of the heat transfer energy transferred from the heater 102 to the resin (pellets) to the shear energy generated by the screw. The energy calculation section 22 calculates the ratio by calculating the ratio of the heat transfer energy to the shear energy.

[0066] The output section 18 is, for example, a display section such as a display. The output section 18 outputs the calculated heat release amount to the outside. As shown in Figure 7 , the output section 18 displays, for example, at least one of the heat transfer energy, the shear energy, and the ratio.

[0067] The output control section 19 is realized, for example, by the CPU acting. The output control section 19 causes the output section 18 to output the calculated heat release amount. The output control section 19 causes the output section 18 to output at least one of the calculated heat transfer energy, the shear energy, and the ratio.

[0068] Next, the flow of the process performed by the control device 1 will be described with reference to Figure 8 .

[0069] First, the performance information acquisition section 14 acquires performance information (step S1). The performance information acquisition section 14 acquires, for example, a plurality of pieces of performance information from the performance information storage section 13.

[0070] Next, the characteristic information acquisition section 21 acquires the characteristic information (step S2). The characteristic information acquisition section 21 acquires, for example, the characteristic information that is previously stored in the characteristic information storage section 20.

[0071] Next, the action information acquisition section 12 acquires the action information (step S3). The action information acquisition section 12 acquires, for example, the action information that is previously stored in the action information storage section 11.

[0072] Next, the surface temperature acquisition section 15 acquires the surface temperature corresponding to the action information (step S4).

[0073] Next, the calculation section 16 calculates the progress of the ratio of the surface temperature to the set temperature with respect to the progress of the heater output included in the action information, based on the acquired action information and the acquired surface temperature (step S5). Next, the estimation section 17 estimates the surface temperature of the heater 102 from the action information, the surface temperature, and the performance information (step S6).

[0074] In step S7, the energy calculation section 22 calculates the heat release amount based on the characteristic information and the estimated surface temperature of the heater 102. The energy calculation section 22, for example, calculates the heat release amount for each heater 102. In addition, the energy calculation section 22 calculates the heat transfer energy, the shear energy, and the ratio of the heat transfer energy to the shear energy.

[0075] In step S8, the output control section 19 outputs the calculated heat release amount, heat transfer energy, shear energy, and the ratio of the heat transfer energy to the shear energy to the output section 18. The output section 18, for example, displays the calculated heat release amount, heat transfer energy, shear energy, and the ratio of the heat transfer energy to the shear energy.

[0076] Next, it is determined whether or not the calculation of the heat release amount is repeated (step S9). In the case where the calculation is repeated (step S9: YES), the processing returns to step S3. On the other hand, in the case where the calculation is ended (step S9: NO), the processing of the present flow is ended.

[0077] Next, the program of the present embodiment is described.

[0078] Each structure included in the control device 1 of the injection molding machine 10 can be realized by hardware, software, or a combination thereof, respectively. Here, the realization by software means the realization by a computer reading and executing a program.

[0079] The program can be stored and supplied to a computer using various types of non-transitory computer readable media. The non-transitory computer readable media include various types of tangible storage media having a physical form. Examples of the non-transitory computer readable media include a magnetic recording medium (such as a floppy disk, a tape, and a hard disk drive), an optical magnetic recording medium (such as a magneto-optical disk), a CD-ROM (Read Only Memory), a CD-R, a CD-R / W, a semiconductor memory (such as a mask ROM, a PROM (Programmable ROM), an EPROM (Erasable PROM), a flash ROM, and a RAM (Random Access Memory)). In addition, the program can be supplied to a computer through various types of transitory computer readable media. Examples of the transitory computer readable media include an electrical signal, an optical signal, and an electromagnetic wave. The transitory computer readable media can supply the program to a computer via a wired communication path, such as an electrical wire and an optical fiber, or a wireless communication path.

[0080] According to the control device 1 and the program of the injection molding machine according to one embodiment described above, the following effects can be obtained.

[0081] (1) An injection molding machine 10 has a cylinder 101, a heater 102 disposed around the cylinder 101, and a screw disposed inside the cylinder 101, and a control device 1 of the injection molding machine 10 is configured to calculate an energy transferred from the heater to a resin at a prescribed time. The control device 1 of the injection molding machine 10 includes an operation information acquisition section 12 configured to acquire operation information including a heater output of the heater 102, a set temperature of the heater 102, and a rotational speed of the screw for a prescribed period immediately before the prescribed time; a characteristic information acquisition section 21 configured to acquire characteristic information regarding a characteristic of heat radiation of the heater 102; a surface temperature acquisition section 15 configured to acquire a surface temperature of the heater 102 for the prescribed period included in the acquired operation information; an achievement information acquisition section 14 configured to acquire an achievement of a change in a ratio of the surface temperature of the heater 102 to the set temperature with respect to a change in the heater output of the heater 102 as achievement information; an estimation section 17 configured to estimate the surface temperature of the heater 102 at the prescribed time on the basis of the operation information, the achievement information, and the acquired surface temperature; and an energy calculation section 22 configured to calculate an amount of heat radiation from a surface of the heater 102 to an environment on the basis of the characteristic information, the operation information, and the estimated surface temperature, and to calculate at least a heat transfer energy transferred from the heater 102 to the resin and a shear energy generated by the screw.

[0082] Further, a program causes a computer to function as a control device 1 of an injection molding machine 10 having a cylinder 101, a heater 102 disposed around the cylinder 101, and a screw disposed inside the cylinder 101, and the control device 1 of the injection molding machine 10 is configured to calculate an energy transferred from the heater to a resin at a prescribed time. The program causes the computer to function as an operation information acquisition section 12 configured to acquire operation information including a heater output of the heater 102, a set temperature of the heater 102, and a rotational speed of the screw for a prescribed period immediately before the prescribed time; a characteristic information acquisition section 21 configured to acquire characteristic information regarding a characteristic of heat radiation of the heater 102; a surface temperature acquisition section 15 configured to acquire a surface temperature of the heater 102 for the prescribed period included in the acquired operation information; an achievement information acquisition section 14 configured to acquire an achievement of a change in a ratio of the surface temperature of the heater 102 to the set temperature with respect to a change in the heater output of the heater 102 as achievement information; an estimation section 17 configured to estimate the surface temperature of the heater 102 at the prescribed time on the basis of the operation information, the achievement information, and the acquired surface temperature; and an energy calculation section 22 configured to calculate an amount of heat radiation from a surface of the heater 102 to an environment on the basis of the characteristic information and the estimated surface temperature, and to calculate at least a heat transfer energy transferred from the heater 102 to the resin and a shear energy generated by the screw.

[0083] Thus, the accuracy of the estimated surface temperature of the heater 102 can be improved regardless of the shape (concave-convex) of the surroundings of the cylinder 101. In addition, a physical sensor or the like does not need to be provided on the surface of the heater 102, so the cost can be suppressed. Furthermore, the heat release amount of each heater 102 can be calculated based on the estimated surface temperature. Thus, the heat release amount from the surface of the heater 102 to the air can be further accurately calculated. As a result, the long life of the heater 102, and the suppression of the driving power of the injection molding machine 10 can be achieved by setting the operation, the molding condition that makes the heat release amount minimum.

[0084] (2) The energy calculation section 22 calculates the ratio of the heat transfer energy transferred from the heater 102 to the resin to the shear energy generated by the screw. Thus, the factor of the temperature change can be further quantitatively obtained.

[0085] (3) The control device 1 of the injection molding machine 10 further has a calculation section 16 that calculates the change in the ratio of the surface temperature to the set temperature with respect to the change in the heater output included in the operation information based on the obtained operation information and the obtained surface temperature, and an estimation section 17 that estimates the surface temperature at a prescribed time using the performance in the performance information that is similar or identical to the change in the ratio and the operation information. Thus, the surface temperature can be easily estimated by obtaining the heater output and the set temperature.

[0086] (4) The surface temperature acquisition section 15 acquires the surface temperature of the heater 102 in the form of the ratio of the surface temperature of the heater 102 to the set temperature, and the estimation section 17 estimates the surface temperature at a prescribed time using the performance in the performance information that is similar or identical to the change in the ratio and the operation information. Thus, the surface temperature can be easily estimated by obtaining the heater output and the set temperature.

[0087] (5) The estimation section 17 estimates the surface temperature at a prescribed time from the ratio of the surface temperature to the set temperature at the time corresponding to the prescribed time shown by the performance that is similar or identical to the change. Thus, the surface temperature is estimated based on the past performance, so the accuracy of the estimated surface temperature can be improved.

[0088] (6) The energy calculation section 22 calculates the energy using the parameter calculated from the surface temperature for a part of the characteristic information. Thus, since the estimated surface temperature is used, the accuracy of the calculated energy can be further improved.

[0089] The above describes preferred embodiments of the control device and the program of the injection molding machine of the present disclosure, but the present disclosure is not limited to the above-described embodiments, and can be appropriately changed.

[0090] For example, in the above embodiment, the performance information acquisition unit 14 can also acquire performance information at multiple points on the surface of a heater 102. Therefore, the estimation unit 17 can also estimate the surface temperature at multiple points on the surface of the heater 102. Then, the energy calculation unit 22 can also calculate the heat release at multiple points on the surface of the heater 102. At this time, the energy calculation unit 22 can also calculate the convective heat release E. Ci and radiative heat release E Ri Let the surface temperature (K) of heater 102 at each measuring point be T. Hm The area (m²) occupied by each measuring point on the surface of heater 102. 2 Let A be the case. im Let the numbers representing each measurement point be m = 1, 2... to calculate the following number 5, and thus determine the heat release.

[0091] [Number 5]

[0092]

[0093]

[0094] Additionally, the energy calculation unit 22 can also calculate the convective heat release E measured at multiple points by calculating the following number 6. Ci ′ and radiative heat release E Ri ′.

[0095] [Number 6]

[0096]

[0097]

[0098] Furthermore, in the above embodiments, such as Figure 9 As shown, the output control unit 19 can also cause the output unit 18 to display the heat transfer energy, shear energy, and total energy in the form of a bar chart. This allows for easy monitoring of the energy status.

[0099] Furthermore, in the above embodiments, such as Figure 10 As shown, the output control unit 19 can also cause the output unit 18 to display the energy ratio in the form of a pie chart. This makes it easy to grasp the energy ratio.

[0100] Furthermore, in the above embodiments, such as Figure 11 As shown, the output control unit 19 can also cause the output unit 18 to display a scatter plot obtained by summarizing the energy at each predetermined time. Therefore, the energy can be displayed in a time sequence, making it easy to monitor energy anomalies.

[0101] Furthermore, in the above embodiments, such as Figure 12 As shown, the output control unit 19 can also cause the output unit 18 to display the heat transfer energy, shear energy, ratio, and total energy at each specified time. For example, the output control unit 19 can also cause the output unit 18 to display the maximum value, minimum value, average value, difference between the maximum and minimum values, and standard deviation for each item.

[0102] Furthermore, in the above embodiment, the action information acquisition unit 12 acquires the action information after the performance information acquisition unit 14 acquires the performance information, but it is not limited to this. It is also possible that the action information acquisition unit 12 acquires the action information before the performance information acquisition unit 14 acquires the performance information.

[0103] Furthermore, in the above embodiments, the injection molding machine 10 can be either a coaxial reciprocating screw type or a plunger type. Additionally, in the above embodiments, the surface temperature of the heater 102 included in the performance information can be either measured by a temperature sensor (not shown) as a direct method, or measured by thermal imaging (radiation thermometer, not shown) as an indirect method.

[0104] Furthermore, in the above embodiment, the output unit 18 can also be configured independently of the control device 1 (injection molding machine 10). Additionally, the control device 1 can manage multiple injection molding machines 10. Furthermore, in the above embodiment, the output control unit 19 can also enable the output unit 18 to display the surface temperature of the heater 102 in addition to the heat released.

[0105] Alternatively, in the above embodiment, the energy calculation unit 22 may perform calculations at a predetermined time, such as per unit time or per cycle time. Alternatively, in the above embodiment, the energy calculation unit 22 may calculate the total energy or the energy per unit time of a predetermined period. Alternatively, the energy calculation unit 22 may calculate the average value for each fixed time period or calculate the energy at a specific moment.

[0106] Furthermore, in the above embodiment, the heat output E of heater 102 is not limited to being calculated using the number 4. H The heat output E of heater 102 can also be calculated based on the power consumption of the heater, calculated from the current flowing in heater 102 and the resistance of heater 102. H .

[0107] Further, in the above-described embodiment, regarding the screw rotation amount R, it is also possible to acquire it as a set value on the injection molding machine 10. Further, regarding the screw rotation amount R, it is also possible to acquire a detection value from a detector (encoder) provided to the screw rotation motor (not shown). The behavior of the motor is not always a rotational speed in accordance with the setting. For the motor, for example, a rising edge time and a falling edge time are required. Further, in a case where the friction with the resin is large, sometimes the rotational speed of the screw does not reach the set rotational speed. Therefore, by using the detection value, it is possible to improve the accuracy of the calculation of the energy.

[0108] Further, in the above-described embodiment, the motor work amount is calculated in a manner of number 3 to be the shear energy E S , but is not limited thereto. It is also possible to calculate the shear energy E S using a value shown by a power meter (not shown) installed in the screw rotation motor.

[0109] Further, in the above-described embodiment, it is also possible to calculate the shear energy E S by a method other than the calculation of the motor work amount. For example, it is also possible to calculate the shear energy E S from the temperature rise amount of the resin generated by the frictional heat of the screw and the resin. Further, for example, it is also possible to calculate the shear energy E S from the viscosity and the deformation speed of the resin.

[0110] Further, in the above-described embodiment, the surface temperature acquisition section 15 can acquire a ratio of the set temperature to the surface temperature instead of the surface temperature. In this case, the control device 1 can not be provided with the calculation section 16.

[0111] Explanation of Reference Numerals

[0112] 1: control device; 10: injection molding machine; 12: action information acquisition section; 14: performance information acquisition section; 16: calculation section; 17: estimation section; 21: characteristic information acquisition section; 22: energy calculation section; 101: cylinder; 102: heater; 103: safety cover.

Claims

1. A control device of an injection molding machine that has a cylinder, a heater disposed around the cylinder, and a screw disposed inside the cylinder, the control device of the injection molding machine being configured to calculate an energy transferred from the heater to a resin at a prescribed time, the control device of the injection molding machine comprising: an operation information acquisition section that acquires operation information including a heater output of the heater, a set temperature of the heater, and a rotational speed of the screw in a prescribed period immediately before the prescribed time; a characteristic information acquisition section that acquires characteristic information related to a characteristic of heat radiation of the heater; a surface temperature acquisition section that acquires a surface temperature of the heater in the prescribed period included in the acquired operation information; an actual performance information acquisition section that acquires an actual performance of a ratio of the surface temperature to the set temperature with respect to a progress of the heater output of the heater as actual performance information; an estimation section that estimates the surface temperature of the heater at the prescribed time based on the operation information, the actual performance information, and the acquired surface temperature; and an energy calculation section that calculates, based on the characteristic information, the operation information, and the estimated surface temperature, an amount of heat radiation from a surface of the heater to an environment, and at least a heat transfer energy transferred from the heater to the resin and a shear energy generated by the screw, wherein the control device further comprises a calculation section that calculates, based on the acquired operation information and the acquired surface temperature, a progress of the ratio of the surface temperature to the set temperature with respect to a progress of the heater output included in the operation information, and the estimation section estimates the surface temperature at the prescribed time using an actual performance included in the actual performance information that coincides with the progress of the operation information and the calculated ratio.

2. The control device of the injection molding machine according to claim 1, wherein the energy calculation section calculates a ratio of the heat transfer energy transferred from the heater to the resin to the shear energy generated by the screw.

3. The control device of the injection molding machine according to claim 1 or 2, wherein the surface temperature acquisition section acquires the surface temperature of the heater in the form of a ratio of the surface temperature to the set temperature of the heater, the estimation section estimates the surface temperature at the prescribed time using an actual performance included in the actual performance information that coincides with the progress of the operation information and the acquired ratio.

4. The control device of the injection molding machine according to claim 1, wherein the estimation section estimates the surface temperature at the prescribed time from a ratio of the surface temperature to the set temperature at a time corresponding to the prescribed time, which is indicated by an actual performance that coincides with the progress of the calculated ratio.

5. The control device of the injection molding machine according to claim 3, wherein the estimation section estimates the surface temperature at the prescribed time from a ratio of the surface temperature to the set temperature at a time corresponding to the prescribed time, which is indicated by an actual performance that coincides with the progress of the acquired ratio. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 6. The control device of the injection molding machine according to claim 1 or 2, wherein the energy calculation section calculates the energy using a parameter calculated from the surface temperature as a part of the characteristic information.

7. A computer-readable medium, which is a non-transitory computer-readable medium that stores a program causing a computer to function as a control device of an injection molding machine having a cylinder, a heater disposed around the cylinder, and a screw disposed inside the cylinder, the control device of the injection molding machine being used to calculate an energy transferred from the heater to a resin at a prescribed time, the program causing the computer to function as: an operation information acquisition section that acquires operation information including a heater output of the heater, a set temperature of the heater, and a rotational speed of the screw for a prescribed period immediately before the prescribed time; a characteristic information acquisition section that acquires characteristic information regarding a characteristic of heat radiation of the heater; a surface temperature acquisition section that acquires a surface temperature of the heater for the prescribed period included in the acquired operation information; an actual performance information acquisition section that acquires an actual performance of a change in a ratio of the surface temperature to the set temperature with respect to a change in the heater output of the heater as actual performance information; an estimation section that estimates the surface temperature of the heater at the prescribed time on the basis of the operation information, the actual performance information, and the acquired surface temperature; and an energy calculation section that calculates an amount of heat radiation from a surface of the heater to an environment on the basis of the characteristic information, the operation information, and the estimated surface temperature, and at least calculates a heat transfer energy transferred from the heater to the resin and a shear energy generated by the screw, wherein the computer is further caused to function as a calculation section that calculates a change in the ratio of the surface temperature to the set temperature with respect to a change in the heater output included in the operation information on the basis of the acquired operation information and the acquired surface temperature, the estimation section estimates the surface temperature at the prescribed time using an actual performance included in the actual performance information that coincides with the change in the operation information and the calculated ratio.

8. The control device of the injection molding machine according to claim 7, wherein the estimation section estimates the surface temperature at the prescribed time using an actual performance included in the actual performance information that coincides with the change in the operation information and the calculated ratio.

9. The control device of the injection molding machine according to claim 7 or 8, wherein the energy calculation section calculates the energy using a parameter calculated from the surface temperature as a part of the characteristic information.

10. The control device of the injection molding machine according to any one of claims 7 to 9, wherein the characteristic information acquisition section acquires the characteristic information regarding the characteristic of the heat radiation of the heater on the basis of a material of the heater, a shape of the heater, and a shape of a resin passage of the cylinder.

11. The control device of the injection molding machine according to any one of claims 7 to 10, wherein the surface temperature acquisition section acquires the surface temperature of the heater on the basis of a temperature of a coolant supplied to the heater.

12. The control device of the injection molding machine according to any one of claims 7 to 11, wherein the actual performance information acquisition section acquires the actual performance of the change in the ratio of the surface temperature to the set temperature with respect to the change in the heater output of the heater on the basis of a temperature of a coolant supplied to the heater.

13. The control device of the injection molding machine according to any one of claims 7 to 12, wherein the estimation section estimates the surface temperature of the heater at the prescribed time on the basis of the operation information, the actual performance information, and the acquired surface temperature.

14. The control device of the injection molding machine according to any one of claims 7 to 13, wherein the energy calculation section calculates the heat transfer energy transferred from the heater to the resin and the shear energy generated by the screw on the basis of the characteristic information, the operation information, and the estimated surface temperature.

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