Control device and program for injection molding machine

Abstract

Provided is a technology which is designed for an injection molding machine comprising a plurality of heaters, and which makes it possible to precisely grasp a plasticization state inside a cylinder. A control device 10 for an injection molding machine 1 comprises: an operation information acquisition unit 11 that acquires operation information related to operation of heaters 24a to 24d and a screw 23; a characteristic information acquisition unit 12 that acquires characteristic information related to characteristics of the injection molding machine 1; a computation unit 15 that computes, on the basis of the acquired operation information and characteristic information, the amount of heat transfer ETi from the heaters 24a to 24d to a molding material for each of a plurality of regions of the heaters 24a to 24d divided in the axial direction, and computes the amount of shear heat generation ES that the molding material receives through the operation of the screw 23; and an output unit 20 that executes a process of displaying the amount of heat transfer ETi together with the amount of shear heat generation ES on a display device 6 distinctively for each of the plurality of regions divided in the axial direction.

Description

Injection molding machine control device and program

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

[0002] Conventionally, injection molding machines are known that melt pellets placed in a hopper in a cylinder and then inject them into a mold. A heater is disposed around the outer periphery of the cylinder of the injection molding machine. The heater heats the cylinder, melting the pellets (molding material). Furthermore, the molding material is kneaded and plasticized by rotating a screw disposed inside the cylinder. In this way, the molding material is plasticized by heat transfer from the heater and shear heating generated by the shearing action of the screw when it rotates.

[0003] For this type of injection molding machine, a technique is known in which the heater surface temperature is estimated based on the heater's set temperature and operating rate, the amount of heat transferred from the heater to the material, and the amount of shear heat generated by the screw are calculated, and then displayed as numerical values, a pie chart, a bar graph, or the like (see, for example, Patent Document 1).

[0004] International Publication No. 2021 / 246524

[0005] The technology described in Patent Document 1 can grasp the relationship between the amount of heat transfer from a heater and the amount of heat generated by shear. However, although it is possible to grasp the proportion of heat transfer and shear in the total energy received by the molding material during the plasticization process by displaying the data, it is difficult to grasp the relationship between heat transfer and shear for each heater in a configuration in which heating is applied using multiple heaters. The conventional technology left room for improvement in terms of grasping the plasticization state inside the cylinder in more detail.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a technique that can grasp the plasticization state inside a cylinder in detail in an injection molding machine equipped with multiple heaters.

[0007] The present disclosure relates to a control device for an injection molding machine that includes a cylinder, a plurality of heaters arranged axially on the cylinder, and a screw arranged inside the cylinder, the control device for an injection molding machine that includes: an operation information acquisition unit that acquires operation information related to the operation of the heater and the screw; a characteristic information acquisition unit that acquires characteristic information related to the characteristics of the injection molding machine; a calculation unit that calculates the amount of heat transfer from the heater to a molding material for each of the heater's multiple axially divided regions based on the acquired operation information and characteristic information, and calculates the amount of shear heat generated by the molding material due to the screw operation; and an output unit that executes processing to display the amount of heat transfer, together with the amount of shear heat generated, on a display device, as a result of the calculation by the calculation unit, distinguished for each of the multiple axially divided regions.

[0008] The present disclosure also provides a program for causing a computer that controls an injection molding machine that includes a cylinder, a plurality of heaters arranged axially on the cylinder, and a screw arranged inside the cylinder to execute the following: an operation information acquisition function that acquires operation information regarding the operation of the heater and the screw; a characteristic information acquisition function that acquires characteristic information regarding the characteristics of the injection molding machine; a calculation function that calculates the amount of heat transfer from the heater to the molding material for each of the heater's multiple axially divided regions based on the acquired operation information and characteristic information, and calculates the amount of shear heat generated by the molding material due to the screw operation; and an output function that executes processing to display the amount of heat transfer, together with the amount of shear heat generated, on a display device, as a result of the calculation by the calculation function, distinguishing between the multiple axially divided regions.

[0009] According to the present disclosure, it is possible to provide a technique that can grasp the plasticization state inside a cylinder in detail in an injection molding machine equipped with multiple heaters.

[0010] FIG. 1 is a schematic diagram showing the configuration of an injection molding machine according to a first embodiment. FIG. 2 is a perspective view showing a heater arranged in a cylinder according to the first embodiment. FIG. 3 is a functional block diagram of a control device for an injection molding machine according to the first embodiment. FIG. 4 is a schematic diagram explaining a heat balance during molding execution. FIG. 5 is a schematic diagram explaining a heat balance when molding is stopped. FIG. 6 is a diagram showing an example of an energy flow inside a cylinder displayed on a display device by an output unit according to the first embodiment. FIG. 7 is a diagram showing an example of a table displayed on a display device by an output unit according to the first embodiment. FIG. 8 is a diagram showing an example of a bar graph displayed on a display device by an output unit according to the first embodiment. FIG. 9 is a diagram showing an example of a pie chart displayed on a display device by an output unit according to the first embodiment. FIG. 10 is a diagram showing an example of an energy flow inside a cylinder and a calculation result displayed on a display device by an output unit according to the first embodiment. FIG. 11 is a flowchart showing an example of a flow of display processing by a control device for an injection molding machine according to the first embodiment. FIG. 12 is a diagram showing an example of an energy flow inside a cylinder displayed on a display device by an output unit according to the second embodiment. FIG. 13 is a diagram explaining a heat balance taking into account the amount of heat radiation. FIG. 14 is a diagram showing an example of an energy flow inside a cylinder displayed on a display device by an output unit according to the third embodiment. FIG. 15 is a diagram showing an example of an energy flow inside a cylinder and a calculation result displayed on a display device by an output unit according to the fourth embodiment. FIG. 16 is a diagram showing an example of a table displayed on a display device by an output unit according to the fourth embodiment. FIG. 17 is a diagram showing an example of a bar graph displayed on a display device by an output unit according to the fourth embodiment. 10 is a table showing conditions for an example of calculation by the control device of the present embodiment, and a bar graph showing the results of calculation by the control device of the present embodiment.

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description of the second and subsequent embodiments, the same reference numerals will be used to designate components common to the first and second embodiments, and the description thereof will be omitted as appropriate.

[0012] [First embodiment] Fig. 1 is a schematic diagram showing the configuration of an injection molding machine 1 according to the first embodiment. Fig. 2 is a perspective view showing heaters 24a to 24d arranged in a cylinder 22 of the injection molding machine 1 according to the first embodiment. The injection molding machine 1 of this embodiment includes an injection unit 2, a mold clamping unit 3, a control device 10, and a display device 6.

[0013] The injection unit 2 is an injection device including a hopper 21, a cylinder 22, a screw 23, and a cooling jacket 26. The cylinder 22 is, for example, a cylindrical body. Resin stored in the hopper 21 is supplied to the cylinder 22. The screw 23 is disposed inside the cylinder 22 and transports the resin to the tip of the cylinder 22 by rotation. A screw head 30 is disposed at the tip of the screw 23 to prevent backflow during injection. The cooling jacket 26 is a device that cools the inside of the cylinder 22 (for example, the root side portion inside the cylinder 22), and cooling water circulates through the cooling jacket 26.

[0014] 2, a plurality of heaters 24a to 24d are arranged, for example, along the axial direction of the cylinder 22. Specifically, a plurality of heaters 24a to 24d are arranged from the nozzle portion 25 at the axial tip of the cylinder 22 to the base end.

[0015] In this embodiment, four heaters 24a to 24d are arranged along the axial direction so as to cover the outer periphery of the cylinder 22. Heater 24a is one of the tip heaters arranged in the nozzle portion 25. Heaters 24b to 24d are located upstream of the nozzle portion 25 in the pellet conveying direction. Heater 24b is one of the tip heaters located closest to the nozzle portion 25 and is located in the metering portion. Heater 24c is located between heaters 24b and 24d and is located in the compression portion inside the cylinder 22. Heater 24d is located farthest from the nozzle portion 25 and is located in the supply portion inside the cylinder 22. Note that the number and positions of heaters 24a to 24d are not limited to the configuration of this embodiment.

[0016] The pellets are melted by heating the cylinder 22 with the heaters 24a to 24d. The melted pellets are transported by the screw 23 to the nozzle portion 25 side and injected into the mold 5.

[0017] The mold clamping unit 3 is a device that clamps the mold 5. When the mold clamping unit 3 clamps the mold 5, a molded product is formed.

[0018] Next, the control device 10 will be described. The control device 10 of the injection molding machine 1 according to the first embodiment is configured using a computer including memories such as a ROM (read only memory) and a RAM (random access memory), a CPU (control processing unit), and a communication control unit, all connected to each other via a bus. The functions and operations of the functional units of the control device 10, which will be described later, are achieved by cooperation between the CPU and memory installed in the computer and the control program stored in the memory.

[0019] The display device 6 is an output device such as a liquid crystal display or a touch panel display.

[0020] Next, the functions of the control device 10 will be described with reference to Fig. 3. Fig. 3 is a functional block diagram of the control device 10 of the injection molding machine 1 according to the first embodiment. The control device 10 includes, as functional units, an operation information acquisition unit 11 (operation information acquisition function) executed by a CPU, a characteristic information acquisition unit 12 (characteristic information acquisition function), a calculation unit 15 (calculation function), and an output unit 20 (output function).

[0021] The operation information acquisition unit 11 acquires operation information related to the operation of the heaters 24a to 24d. In this embodiment, the operation information related to the heaters 24a to 24d is the operation rate of each of the heaters 24a to 24d. The operation rate is an index of the operation state indicated, for example, from 0 to 100%. The operation rate is determined based on the output, such as the voltage, of the heaters 24a to 24d, for example.

[0022] The operation information acquiring unit 11 also acquires, as operation information, information relating to the operation of the screw 23. The information relating to the operation of the screw 23 is, for example, the motor current during metering, the rotational angular velocity of the screw 23, and the like.

[0023] The characteristic information acquisition unit 12 acquires characteristic information indicating the characteristics of the injection molding machine 1. The characteristic information is, for example, the capacity of the heaters 24a to 24d. The capacity of the heaters 24a to 24d here is a rated capacity of 1500 W at 200 V.

[0024] The characteristic information acquisition unit 12 also acquires, as characteristic information, information relating to the characteristics of the screw 23. The information relating to the characteristics of the screw 23 is, for example, the reduction ratio between the screw 23 and the motor that rotates the screw 23, the mechanical efficiency, the torque constant of the rotary motor that rotates the screw 23, etc.

[0025] The calculation unit 15 calculates the heat generation amount, heat transfer amount, and shear heat generation amount of the heaters 24a to 24d based on the acquired operation information and characteristic information.

[0026] The calculation of the heat generation amount by the calculation unit 15 will be described below. The calculation unit 15 calculates, for example, the heat generation amount of each of the heaters 24a to 24d for a predetermined time period in a state where the cylinder 22 is maintained at a preset temperature.

[0027] An example of a method for calculating the calorific value by the calculation unit 15 will be described. The calorific value can be calculated, for example, by the following formula (1). Note that E in formula (1) Ｈｉ is the heat generation amount, t １ is the calculation start time, t ２ is the calculation end time, W ｉ is the heater capacity, r ｉ represents the heater operation rate, and i is a number (i=0, 1, 2, 3) that identifies the heaters 24a to 24d.

[0028]

[0029] The heater rated capacity is determined by a specific voltage V Ｒ However, the voltage supplied to the injection molding machine 1 may actually be different from the specified voltage. Therefore, the calculation unit 15 calculates the rated voltage V of the heaters 24a to 24d as shown in the following formula (2): Ｒ and the actual value of the power supply voltage V of the injection molding machine 1, and correction may be performed to calculate the heat generation amount.

[0030]

[0031] The calculation of the heat transfer amount by the calculation unit 15 will be described. The calculation unit 15 calculates the heat transfer amount from each of the heaters 24a to 24d to the resin based on the calculated heat generation amount. An example of a method for calculating the heat transfer amount by the calculation unit 15 will be described. The heat transfer amount from the heaters 24a to 24d to the resin is calculated as E Ｔｉ The heat generation amount during molding is expressed as E when the cylinder 22 is maintained at a predetermined set temperature. Ｈｉ The heat generation amount when molding is stopped is E' Ｈｉ As a result, the heat transfer amount is expressed by the following formula (3): As shown in the formula (3), the heat generation amount E Ｈｉ and the heat generation amount E' when molding stops Ｈｉ The difference in heat transfer amount E Ｔｉ The calculated heat transfer amount E Ｔｉ If the value is negative, no heat is transferred from the heaters 24a to 24d to the resin, and in this case the amount of heat transfer is set to 0.

[0032]

[0033] The formula (3) will be described with reference to Fig. 4 and Fig. 5. In the description using Fig. 4 and Fig. 5, the heater 24b (i=1) will be used as an example.

[0034] 4 is a schematic diagram illustrating the heat balance during molding. As shown in FIG. 4, when considering the heat balance during molding, the heat generation amount E during molding to maintain the cylinder 22 at the set temperature is Ｈ１ The amount of heat transferred from the front (the nozzle portion 25 side) E Ａ０ and the amount of heat transferred to the resin E Ｔｉ The amount of heat dissipated from the heater 24b to the outside of the cylinder 22 is E Ｒｉ and the heat transfer amount E Ａ１ The sum of and is equal to.

[0035] Fig. 5 is a schematic diagram illustrating the heat balance when molding is stopped. As shown in Fig. 5, when considering the heat balance when molding is stopped, unlike when molding is in progress, the screw 23 is stopped inside the cylinder 22, and the resin is not flowing and remains stagnant. In this state, it can be considered that the resin temperature is the same as the temperature of the cylinder 22, so the heat generated by the heater 24b is not transmitted to the resin. Therefore, as shown in Fig. 5, the heat generation amount E' when molding is stopped, which maintains the cylinder 22 at the set temperature, is Ｈ１ The amount of heat transferred from the front (the nozzle portion 25 side) E Ａ０ and the amount of heat dissipated to the outside of the cylinder 22 E Ｒｉ The amount of heat transferred to the rear (opposite side of the nozzle portion 25) E Ａ１ The sum of and is equal to.

[0036] Therefore, the heat generation amount E Ｈ１ From the calorific value E' Ｈ１ As shown in equation (3), the amount of heat generated during molding E Ｈｉ and the heat generation amount E' when molding stops Ｈｉ Based on the heat transfer amount E Ｔｉ can be obtained.

[0037] The calculation of the shear heat generation amount by the calculation unit 15 will be described. The calculation unit 15 calculates the shear heat generation amount due to the rotation of the screw 23 based on the operation information acquired by the operation information acquisition unit 11 and the characteristic information acquired by the characteristic information acquisition unit 12. The shear heat generation amount is the amount of heat generated due to shear caused by the rotation of the screw 23.

[0038] An example of a method for calculating the amount of shear heat generated by the calculation unit 15 will be described. The calculation unit 15 integrates the torque of the screw 23 during the metering operation based on the operation information and characteristic information of the motor to calculate the energy E Ｄ For example, the energy E for rotating the screw 23 is calculated by the following formula (4): Ｄ Calculate E in Equation (4). Ｄ is the energy for rotating the screw 23, K Ｔrepresents the torque constant of the rotary motor that rotates the screw 23, r represents the motor current during metering, R represents the reduction ratio between the motor and the screw 23, ω represents the rotational angular velocity of the screw 23, and η represents the mechanical efficiency.

[0039]

[0040] When the energy calculated by the formula (4) is the shear heat generation amount of the resin, the energy E Ｄ is the shear heat generation amount E Ｓ (E Ｄ = E Ｓ However, if excessive heat is generated by the rotation of the screw 23, the inside of the cylinder 22 becomes hotter than the outside, and the heater heat transfer amount E Ｔｉ This heat amount is the energy E that rotates the screw 23. Ｄ Because of this, E Ｄ = E Ｓ Therefore, as shown in equation (5), the negative heat transfer amount (negative heater heat transfer amount E Ｔｉ The sum of E Ｄ However, in the formula (5), E Ｔｉ is only negative.

[0041]

[0042] The calculation unit 15 also calculates the heat transfer amount E Ｔｉ and shear heat generation E Ｓ Based on the total heat received by the molding material E Ｍ Calculate the total amount of heat received E Ｍ can be calculated using, for example, the following formula (6). Ｔｉ If there is a negative value for , it is used as 0 in the calculation.

[0043]

[0044] The above describes the calculation of the heat generation amount, heat transfer amount, and shear heat generation amount by the calculation unit 15. Next, the output unit 20 that outputs the calculation results of the calculation unit 15 will be described.

[0045] The output unit 20 executes processing for displaying information based on the calculation results of the calculation unit 15 on the display device 6. The output unit 20 may be configured to output the calculation results of the calculation unit 15 to an external computer connected to the injection molding machine 1, which is different from the display device 6 of the injection molding machine 1.

[0046] Next, Fig. 6 is a diagram showing an example of the energy flow inside the cylinder 22 displayed on the display device 6 by the output unit 20 of the first embodiment. Fig. 7 is a diagram showing an example of a table displayed on the display device by the output unit 20 of the first embodiment.

[0047] FIG. 6 shows the position of the screw 23 inside the cylinder 22 and the shear heat generation amount E Ｓ The position of the heater 24a is indicated by the corresponding heat transfer amount E Ｔ０ is shown, and the corresponding heat transfer amount E Ｔ１ is shown, and the corresponding heat transfer amount E Ｔ２ is shown, and the corresponding heat transfer amount E Ｔ３ In addition, the total heat received amount E ｍ is displayed.

[0048] FIG. 7 shows the shear heat generation amount E Ｓ The calculation result, the heat transfer amount E Ｔ０ The calculation result of the heat transfer amount E Ｔ１ The calculation result, the heat transfer amount E Ｔ２ The calculation result, the heat transfer amount E Ｔ３ The calculation result of the total heat received E ｍ The calculation results are shown in a table format. In this table, the heat transfer amounts of the heaters 24a to 24d are displayed separately.

[0049] The output unit 20 executes a process of displaying, for example, an image of the content shown in Fig. 6 and an image of the content shown in Fig. 7 simultaneously or selectably by switching operation on the display device 6. This allows the user to confirm the content shown in Fig. 6 and the content shown in Fig. 7 and to determine the heater heat transfer amount E of each region of the heaters 24a to 24d. Ｔｉ , shear heat generation amount E Ｓ、 Total heat received E ｍ It is possible to grasp the following.

[0050] Next, different display examples will be described with reference to Fig. 8 to Fig. 10. Fig. 8 is a diagram showing an example of a bar graph displayed on the display device 6 by the output unit 20 of the first embodiment. The bar graph in Fig. 8 shows the amount of heat transfer E Ｔ１ , the heat transfer amount E of the heater 22c Ｔ２ , the heat transfer amount E of the heater 24d Ｔ３ , shear heat generation amount E Ｓ The display area is visually displayed with a distinction. Ｔ０ is omitted because its contribution is very small.

[0051] 9 is a diagram showing an example of a pie chart displayed on the display device 6 by the output unit 20 according to the first embodiment. Ｔ１ , the heat transfer amount E of the heater 22c Ｔ２ , the heat transfer amount E of the heater 24d Ｔ３ , shear heat generation amount E Ｓ The display area is visually displayed with a distinction. Ｔ０ is omitted because its contribution is very small.

[0052] 10 is a diagram showing an example of the energy flow inside the cylinder 22 and the calculation results displayed on the display device 6 by the output unit 20 in the first embodiment. In FIG. 10, the inside of the cylinder 22 and the positions of the heaters 24a to 24d are shown similarly to FIG. 6, and the shear heat generation amount E Ｓ , Heat transfer amount E Ｔ０ , Heat transfer amount E Ｔ１ , Heat transfer amount E Ｔ２ , Heat transfer amount E Ｔ３ , total heat received E ｍ The calculation result of the above is displayed. By checking the content shown in Fig. 10, the user can intuitively grasp the heat transfer amount of the heaters 24a to 24d for each region.

[0053] Next, a series of flow of the display process will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the flow of the display process by the control device 10 of the injection molding machine 1 according to the first embodiment.

[0054] First, the characteristic information acquisition unit 12 acquires characteristic information indicating the characteristics of the injection molding machine 1 (step S10), and the operation information acquisition unit 11 acquires the availability rates related to the operations of the heaters 24a to 24d as operation information (step S11). The operation information and characteristic information are acquired, for example, from various sensors, a storage unit (not shown) of the control device 10, an external computer (not shown), etc.

[0055] The calculation unit 15 calculates the heat generation amounts of the heaters 24a to 24d based on the acquired operation information and characteristic information (step S12). The calculation unit 15 calculates the heat generation amounts of the heaters 24a to 24d in a state in which the cylinder 22 is maintained at a predetermined set temperature based on, for example, the operation rates and capacities of the heaters 24a to 24d.

[0056] Next, the calculation unit 15 calculates the amount of heat transferred from the heaters 24a to 24d to the resin (step S13). The calculation unit 15 calculates, for example, the amount of heat generated by the heaters 24a to 24d during molding E Ｈｉ and the heat generation amount E' of the heaters 24a to 24d when molding is stopped. Ｈｉ and are substituted into the above equation (2), and the amount of heat transferred from the heaters 24a to 24d to the resin E Ｔｉ Calculate the following.

[0057] Next, the calculation unit 15 calculates the amount of shear heat generation based on the motion information acquired by the motion information acquisition unit 11 and the characteristic information acquired by the characteristic information acquisition unit 12 (step S14).

[0058] Next, the output unit 20 executes a process for displaying information based on the calculation results of the calculation unit 15 on the display device 6 (step S15). In this process, the output unit 20 executes a process for displaying numerical values, characters, symbols, graphs, pictures, or combinations thereof, etc., that indicate the calculation results of the calculation unit 15. The output unit 20 outputs to the display device 6, for example, images having the contents shown in FIGS. 6 to 10.

[0059] After the processing by the output unit 20 in step S15, if the molding process is to be continued, the control device 10 returns to step S11 and executes the processes from step S11 onward again (step S16; Yes). On the other hand, if the control device 10 detects that the molding process has stopped, it executes a process to stop the molding and ends the flow (step S16; No). Note that the continuation or stop of the molding process is determined by the control device 10 based on, for example, whether the user's operation or the plasticization state satisfies predetermined conditions.

[0060] The control device 10 for the injection molding machine 1 according to the first embodiment described above has the following advantages. That is, the injection molding machine 1 includes a cylinder 22, a plurality of heaters 24a to 24d arranged axially on the cylinder 22, and a screw 23 arranged inside the cylinder 22. The control device 10 for the injection molding machine 1 includes an operation information acquisition unit 11 that acquires operation information relating to the operations of the heaters 24a to 24d and the screw 23, a characteristic information acquisition unit 12 that acquires characteristic information relating to the characteristics of the injection molding machine 1, and a control unit 13 that calculates the amount of heat transfer E from the heaters 24a to 24d to the molding material based on the acquired operation information and characteristic information. Ｔｉ is calculated for each of the heater regions 24a to 24d divided into a plurality of regions in the axial direction, and the shear heat generation amount E Ｓ and a calculation unit 15 that calculates the shear heat generation amount E Ｓ Along with the heat transfer amount E Ｔｉ and an output unit 20 that executes a process of displaying the image on the display device 6 by dividing the image into a plurality of regions in the axial direction. The functions of the control device 10 are realized by a program stored in a storage unit (storage medium).

[0061] As a result, the shear heat generation amount E Ｓ and the heat transfer amount E for each region Ｔｉis displayed on the display device 6, allowing the user to accurately grasp the plasticization state inside the cylinder 22. The grasped plasticization state can be used as an indicator for adjusting injection molding conditions. For example, if there is a recommended optimal distribution of each energy depending on the material used, it is possible to adjust the molding conditions so that the breakdown of output energy approaches that optimal distribution. In addition, the information output by the output unit 20 can also be used to investigate the cause of molding defects when they occur.

[0062] In this embodiment, the calculation unit 15 calculates the heat generation amount E of the heaters 24a to 24d during molding in a state where the cylinder 22 is maintained at a predetermined set temperature. Ｈｉ and the heat generation amount E' of the heaters 24a to 24d when molding is stopped in a state where the cylinder 22 is maintained at a predetermined set temperature. Ｈｉ Based on this, the amount of heat transferred from the heaters 24a to 24d to the molding material E Ｔｉ This allows the user to accurately grasp the plasticization state of the resin even during continuous molding without the need for a special sensor. There is no need to provide an additional sensor or the like on the cylinder 22, and the heat transfer amount E is calculated based on the information that the injection molding machine 1 has already collected and possesses. Ｔｉ can be calculated.

[0063] In this embodiment, the output unit 20 displays at least one of a table, a bar graph, a pie chart, a band graph, and an energy flow diagram on the display device 6. This allows the plasticization state (shear heat generation amount E Ｓ , heat transfer amount E Ｔｉ ) is displayed in a visually easy-to-understand format, allowing the user to intuitively grasp the plasticization state more easily.

[0064] The configuration of the first embodiment has been described above. Below, an embodiment having a configuration different from the first embodiment will be described.

[0065] Second Embodiment The energy balance around the cylinder 22 during plasticization can be expressed by the following equation (7). The input energy on the left side is the heat generation amount E for each of the heaters 24a to 24d used for plasticizing the material. Ｈｉ The sum of the energy EＤ The right side is the heat transfer amount E for each of the heaters 24a to 24d, which is the effective energy. Ｔｉ The sum of the shear heat generation amount E Ｓ On the other hand, the amount of heat radiation E from each of the heaters 24a to 24d is wasted energy that is not used for plasticizing the resin. Ｒｉ It should be noted that there is also energy that moves between the heater regions inside the cylinder 22, but this moving energy does not appear in the overall energy balance and is therefore not included in equation (7).

[0066]

[0067] 12 is a diagram showing an example of the energy flow inside the cylinder 22 displayed on the display device 6 by the output unit 20 of the second embodiment. The output unit 20 of the second embodiment outputs the heat generation amount E Ｈｉ and the energy E for rotating the screw 23 Ｄ The calculation result is displayed on the display device 6. Ｈｉ and the energy E for rotating the screw 23 Ｄ is calculated by the calculation unit 15 as described in the first embodiment.

[0068] The heat generation amount E calculated by the calculation unit 15 Ｈｉ are displayed on the display device 6 as the calculation results for each of the heaters 24a to 24d. For example, for the heater 24a, the heat generation amount E Ｈ０、 Heat generation amount E Ｈ１、 Heat generation amount E Ｈ２、 Heat generation amount E in heater 24d Ｈ３、 is displayed as the calculation result.

[0069] Heat generation amount E of heaters 24a to 24d Ｈｉ are displayed for each of a plurality of regions divided in the axial direction, such as the table in Fig. 7, the bar graph in Fig. 8, and the pie chart in Fig. 9. Along with these calculation results, the output unit 20 displays the energy flow shown in Fig. 12 on the display device 6. Note that, as shown in Fig. 10, the numerical values ​​of the calculation results may be displayed in parallel with the energy flow in Fig. 12.

[0070] As described above, the calculation unit 15 of the second embodiment calculates the energy required to rotate the screw 23. As a result, the input energy during the plasticization process is output as a calculation result to the display device 6, allowing the user to comprehensively grasp the energy balance. The ratio between input energy and effective energy is easy to understand, and the user can easily grasp the quality of energy efficiency. The user can search for optimal conditions while considering the balance between the plasticization state (quality) and energy efficiency.

[0071] [Third embodiment] Fig. 13 is a diagram illustrating the heat balance taking into account the amount of heat radiation. Fig. 13 shows the heat balance during molding and when molding is stopped in tabular form for each heater 24a to 24d. Fig. 14 is a diagram showing an example of the energy flow inside the cylinder 22 displayed on the display device 6 by the output unit 20 of the third embodiment.

[0072] The calculation unit 15 of the third embodiment calculates the amount of heat radiation E from each region of the heaters 24a to 24d to the outside of the cylinder 22, which is the reactive energy in plasticization. Ｒｉ Calculate the following.

[0073] The calculation unit 15 calculates the amount of heat transferred E Ａｉ is calculated using Fourier's law based on the axial temperature gradient of the cylinder 22, the cross-sectional area of ​​the cylinder 22, and the thermal conductivity. The axial temperature gradient of the cylinder 22 can be calculated from the position and set temperature of each control point. When the set temperatures of adjacent regions are the same, the amount of transferred heat E Ａｉ becomes 0, and no calculation is required. In addition, the direction from the tip end side (injection side) of the cylinder 22 to the rear end side (base end side) is considered positive.

[0074] In the table of FIG. 13, the amount of heat transferred E Ａ０ indicates the amount of heat transfer between the region of the heater 24a of the nozzle portion 25 and the region of the heater 24b adjacent to the rear end side of the heater 24a. Ａ１ indicates the amount of heat transfer between the region of the heater 24b and the region of the heater 24c adjacent to the rear end side of the heater 24b. Ａ２ indicates the amount of heat transfer between the region of heater 24c and the region of heater 24d adjacent to the rear end side of heater 24c.

[0075] The calculation unit 15 calculates the amount of transferred heat E Ａｉ and the heat generation amount E' when molding stops Ｈｉ Based on the heat radiation amount E from each region to the outside of the cylinder 22 Ｒｉ Using the heat balance equation shown in the table of FIG. 13, the amount of heat radiation E Ｒ０ is the heat generation amount E' when molding is stopped Ｈ０ Amount of heat transferred from E Ａ０ This heat dissipation amount E Ｒ０ includes the amount of heat dissipated from the surface of the heater 24a to the atmosphere as well as the amount of heat dissipated to the mold in contact with it.

[0076] Similarly, the heat radiation amount E in the region of the heater 24b Ｒ１ is the heat generation amount E' when molding is stopped Ｈ１ The amount of heat transferred to Ａ０ From the sum of these, the amount of heat transferred E Ａ１ The heat radiation amount E of the heater 24c area can be calculated by subtracting Ｒ２ is the heat generation amount E' when molding is stopped Ｈ２ The amount of heat transferred to Ａ１ From the sum of these, the amount of heat transferred E Ａ２ The heat radiation amount E in the region of the heater 24d can be calculated by subtracting Ｒ３ is the heat generation amount E' when molding stops Ｈ３ The amount of heat transferred to Ａ２ This heat dissipation amount E Ｒ３ includes the amount of heat dissipated from the surface of the heater 24d to the atmosphere, as well as the amount of heat dissipated to the cooling water and the machine body.

[0077] The output unit 20 displays the energy flow shown in FIG. 14 on the display device 6, and also displays the heat dissipation amount E using a table, a bar graph, a pie chart, or the like. Ｒｉ The calculation results are displayed so that they can be distinguished for each of the multiple regions divided in the axial direction. Ｓ , Heat transfer amount E Ｔｉ , total heat received E ｍ , the energy E that rotates the screw 23 Ｄ , heat generation amount E Ｈｉ In addition, the heat dissipation amount E ＲｉAs shown in FIG. 10, the output unit 20 adds the heat dissipation amount E Ｒｉ The numerical values ​​of the calculation results including the above may be displayed in parallel.

[0078] As described above, the calculation unit 15 of the third embodiment calculates the amount of heat transferred in the cylinder 22 E Ａｉ is calculated for each of the regions divided in the axial direction.

[0079] In this embodiment, the calculation unit 15 calculates the amount of heat transferred E in the cylinder 22 based on the cross-sectional shape of the cylinder 22, the position and temperature of each cylinder temperature control point, and the thermal conductivity. Ａｉ This allows the transfer energy to be calculated without complex processing.

[0080] In this embodiment, the calculation unit 15 calculates the amount of heat radiation outside the cylinder 22 for each of the multiple regions divided in the axial direction. This makes it possible to display the reactive energy in the plasticization process as the calculation result of the calculation unit 15. Therefore, by adding the reactive energy to the display on the display device 6, the energy balance can be grasped more comprehensively.

[0081] In this embodiment, the calculation unit 15 calculates the amount of heat transferred E Ａｉ and the heat generation amount E of the heaters 24a to 24d when molding is stopped in a state where the cylinder 22 is maintained at a predetermined set temperature. Ｈｉ Based on this, the amount of heat radiation E Ｒｉ This allows the amount of heat dissipation E to be calculated without the need for additional sensors or complex processing. Ｒｉ can be calculated.

[0082] 15 is a diagram showing an example of the energy flow inside the cylinder 22 and the calculation result displayed on the display device 6 by the output unit 20 of the fourth embodiment. The output unit 20 of the fourth embodiment outputs the heat radiation amount E Ｒｉ In addition, the heat transfer amount E Ａｉ The calculation results are also displayed on the display device 6.

[0083] FIG. 15 shows the shear heat generation amount E Ｓ , Heat transfer amount E Ｔｉ, total heat received E ｍ , the energy E that rotates the screw 23 Ｄ , heat generation amount E Ｈｉ , heat radiation amount E Ｒｉ , amount of heat transferred E Ａｉ The calculation results (numerical values) of each heat quantity are displayed together with the energy flow. The calculation method for each heat quantity is the same as in the above embodiment.

[0084] The output unit 20 may display the various heat quantities on the display device 6 in a format different from that of Fig. 15. Fig. 16 is a diagram showing an example of a table displayed on the display device 6 by the output unit 20 according to the fourth embodiment.

[0085] In the table of FIG. 16, the heat generation amount E Ｈｉ and the energy E for rotating the screw 23 Ｄ The calculated value of the above and the sum of the calculated values ​​are shown as the input energy. Ｔｉ , shear heat generation amount E Ｓ and total heat received E ｍ The calculated value is shown as the effective energy. Ｒｉ The calculated value and the total value of the calculated results are shown as reactive energy. Ｈｉ , Heat transfer amount E Ｔｉ and heat dissipation amount E Ｒｉ The calculated values ​​are shown for each region of the heaters 24a to 24d. Ａｉ is the heat transfer amount E of each heater so that the position among the heaters 24a to 24d can be specified. Ｔｉ The transfer energy is shown as the position between

[0086] 17 is a diagram showing an example of a bar graph displayed on the display device 6 by the output unit 20 of the fourth embodiment. At the top of FIG. 17, the heat generation amount E of each region of the heaters 24a to 24d is shown. Ｈｉ and the energy E that rotates the screw 23. Ｄ The ratio of the input energy between the heaters 24a to 24d is shown by the squares dividing the bands. Ｔｉ and shear heat generation E ＳThe composition ratio of the heat dissipation amount E as reactive energy Ｒｉ The composition ratio of and are shown. Furthermore, between the upper and lower bar graphs, the transferred heat amount E Ａｉ is shown.

[0087] The output unit 20 can display, for example, the table of FIG. 16 and the bar graph of FIG. 17 on the display device 6 together with the energy flow of FIG. 15 and the energy flow of FIG. 15 from which the numerical values ​​of the calculation results have been omitted.

[0088] [Fifth Embodiment] In the fifth embodiment, the heat transfer amount E for each of the heaters 24a to 24d is Ｔｉ is the total heat received E Ｍ The output unit 20 outputs the total amount of received heat E Ｍ The heat transfer amount E of the heater 24a Ｔ０ Ratio of total heat received E Ｍ The heat transfer amount E of the heater 24b Ｔ１ Ratio of total heat received E Ｍ The heat transfer amount E of the heater 24c Ｔ２ Ratio of total heat received E Ｍ The heat transfer amount E of the heater 24d Ｔ３ The ratio is output to the display device 6.

[0089] In the fifth embodiment, the calculation unit 15 calculates the heat transfer amount E Ｔｉ and shear heat generation E Ｓ Based on this, the total heat received by the molding material E Ｍ The output unit 20 outputs the heat transfer amount E from at least the heaters 24a to 24d among the calculation results of the calculation unit 15. Ｔｉ and shear heat generation E Ｓ The total heat received E Ｍ This makes it easier to understand the contribution of heat transfer from each heater and shear heat generation during plasticization.

[0090] Next, an example of injection molding actually performed using the control device 10 of the above embodiment will be described. FIG. 18 is a table showing conditions for an example of calculations performed by the control device 10 of this embodiment. FIG. 18 shows multiple conditions for injection molding. Condition 1 in the table is a set temperature of 220°C for heater 24a, a set temperature of 220°C for heater 24b, a set temperature of 220°C for heater 24c, a set temperature of 220°C for heater 24d, a set temperature below the hopper of 50°C, a rotation speed of 50 rpm, and one cycle of 30 seconds. Condition 2 is a set temperature of 220°C for heater 24a, a set temperature of 220°C for heater 24b, a set temperature of 220°C for heater 24c, a set temperature of 220°C for heater 24d, a set temperature below the hopper of 50°C, a rotation speed of 300 rpm, and one cycle of 15 seconds. Condition 3 is a setting temperature of 220°C for heater 24a, 220°C for heater 24b, 200°C for heater 24c, and 180°C for heater 24d, a setting temperature below the hopper of 50°C, a rotation speed of 50 rpm, and a cycle time of 30 seconds. Condition 4 is a setting temperature of 220°C for heater 24a, 220°C for heater 24b, 200°C for heater 24c, and 180°C for heater 24d, a setting temperature below the hopper of 50°C, a rotation speed of 300 rpm, and a cycle time of 15 seconds. Conditions 1 to 4 all share the same screw diameter of 32 mm, resin polypropylene (PP), metering stroke of 64 mm, and back pressure of 2 MPa.

[0091] Fig. 19 is a bar graph showing the calculation results by the control device 10 of this embodiment. Fig. 19 shows the calculation results when injection molding was performed under conditions 1 to 4 shown in the table of Fig. 18. The heat transfer amount of the heater 24a of the nozzle portion 25 is omitted because its contribution is very small.

[0092] The height of the vertical axis in Figure 19 indicates the total amount of heat received by the resin (molding material). Because the set temperature at the tip end of the cylinder 22 is the same, the total amount of heat received is not significantly different, but it can be seen that the proportion of each amount of heat received is significantly different.

[0093] Under condition 1, the resin is sufficiently preheated by heater 24d, located upstream of the flow path, and also receives a large amount of heat from heater 24c. Because heater 24b, located downstream of the flow path, receives only a small amount of heat, it can be seen that by the time it reaches this region (the metering section), the resin temperature is roughly at the set point. Furthermore, because it is difficult to control the supply rate, the value per cycle is unstable, and the amount of heat generated by shear is small, these conditions are conducive to achieving very good plasticization quality. Under conditions 2 and 3, the preheating received by heater 24d is low and the amount of heat generated by shear is high, indicating that the plasticization quality is worse than under condition 1. However, under condition 3, the reduced preheating by heater 24d is compensated for by heater 24c, indicating that the plasticization quality is better than under condition 2. Under condition 4, heater 24d receives almost no preheating, and the majority of the heat is generated by shear. Therefore, condition 4 is a condition that tends to result in unstable plasticization quality. Furthermore, because the heater 24b located downstream of the flow path also receives a very large amount of heat, it is thought that the heat supply is not enough and the resin temperature in the metering section is significantly below the set temperature. In this case, it is thought that this will cause poor filling in the mold and increase the load on the screw 23 and screw head 30 during metering, increasing the possibility of damage. As such, this example demonstrates that the control device 10 of this embodiment can grasp the plasticization state in detail.

[0094] The above-described series of processes can be executed by hardware or software. In other words, the above-described functional configuration is merely exemplary and is not particularly limited. That is, it is sufficient for a computer to have the functionality to execute the above-described series of processes as a whole, and the functional blocks used to realize these functions are not particularly limited to the above-described example. Furthermore, the locations of the functional blocks are also not particularly limited and may be arbitrary. For example, one functional block may be configured as a single piece of hardware, a single piece of software, or a combination thereof. When the series of processes are executed by software, the program that constitutes the software is installed into a computer or the like from a network or a recording medium. The computer may be a computer built into dedicated hardware. Furthermore, the computer may be a computer capable of executing various functions by installing various programs, such as a server, a general-purpose smartphone, or a personal computer.

[0095] A recording medium containing such a program may be constituted not only by a removable medium (not shown) that is distributed separately from the device main body in order to provide the program to users, but also by a recording medium that is provided to users in a state where it is pre-installed in the device main body. Since the program can be distributed via a network, the recording medium may be installed in or accessible from a computer that is connected to or connectable to the network. Furthermore, the steps that describe the program recorded on the recording medium include not only processes that are performed chronologically in accordance with the order in which they are written, but also processes that are not necessarily processed chronologically but are executed in parallel or individually.

[0096] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0097] The following supplementary notes are further disclosed regarding the above-described embodiment and modified examples. (Supplementary Note 1) A control device (10) for an injection molding machine (1) including a cylinder (22), a plurality of heaters (24a to 24d) arranged in the axial direction of the cylinder (22), and a screw (23) arranged inside the cylinder (22), comprising: an operation information acquisition unit (11) that acquires operation information related to the operation of the heaters (24a to 24d) and the screw (23), a characteristic information acquisition unit (12) that acquires characteristic information related to the characteristics of the injection molding machine, and a calculation unit (15) that calculates the amount of heat transfer from the heaters (24a to 24d) to a molding material for each of a plurality of axially divided regions of the heaters (24a to 24d) based on the acquired operation information and characteristic information, and calculates the amount of shear heat generated by the molding material due to the operation of the screw (23). and an output unit (20) that executes a process of displaying, on a display device (6), the amount of heat transfer along with the amount of shear heat generated as a result of calculation by the calculation unit (15), distinguishing the amount of heat transfer for each of a plurality of regions divided in the axial direction.

[0098] (Note 2) In the control device (10) of the injection molding machine (1) described above, the calculation unit (15) calculates the amount of heat transferred from the heaters (24a to 24d) to the molding material based on the amounts of heat generated by the heaters (24a to 24d) when molding is in progress with the cylinder (22) maintained at a predetermined set temperature, and the amounts of heat generated by the heaters (24a to 24d) when molding is stopped with the cylinder (22) maintained at a predetermined set temperature.

[0099] (Note 3) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the energy for rotationally driving the screw (22).

[0100] (Note 4) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the amount of heat transferred within the cylinder (22) for each of the regions divided in the axial direction.

[0101] (Supplementary Note 5) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the amount of heat transferred within the cylinder (22) based on the cross-sectional shape of the cylinder (22), the position and temperature of each cylinder temperature control point, and the thermal conductivity.

[0102] (Note 6) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the amount of heat radiation to the outside of the cylinder (22) for each of a plurality of regions divided in the axial direction.

[0103] (Supplementary Note 7) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the amount of heat dissipated outside the cylinder (22) based on the amount of heat transferred within the cylinder (22) and the amount of heat generated by the heaters (24a to 24d) when molding is stopped while the cylinder (22) is maintained at a predetermined set temperature.

[0104] (Note 8) In the control device (10) of the injection molding machine (1), the calculation unit (15) calculates the total amount of heat received by the molding material based on the amount of heat transferred from the heaters (24a to 24d) and the amount of shear heat generated, and the output unit (20) outputs at least the amount of heat transferred from the heaters (24a to 24d) and the amount of shear heat generated, among the calculation results of the calculation unit (15), in proportion to the total amount of heat received.

[0105] (Supplementary Note 9) In the control device (10) of the injection molding machine (1), the output unit (20) displays at least one of a table, a bar graph, a pie chart, a band graph, and an energy flow diagram on the display device (6).

[0106] (Supplementary Note 10) A computer for controlling an injection molding machine (1) including a cylinder (22), a plurality of heaters (24a to 24d) arranged in the axial direction on the cylinder (22), and a screw (23) arranged inside the cylinder (22) is caused to execute: an operation information acquisition function for acquiring operation information related to operations of the heaters (24a to 24d) and the screw (23); a characteristic information acquisition function for acquiring characteristic information related to characteristics of the injection molding machine; a calculation function for calculating the amount of heat transfer from the heaters (24a to 24d) to a molding material for each of the heaters (24a to 24d) divided into multiple regions in the axial direction based on the acquired operation information and characteristic information, and for calculating the amount of shear heat generated by the molding material due to operation of the screw (23); and an output function for executing a process for displaying the amount of heat transfer together with the amount of shear heat generated for each of the multiple regions divided into the axial direction on a display device (6) as a result of the calculation function.

[0107] REFERENCE SIGNS LIST 1 injection molding machine 10 control device 11 operation information acquisition unit 12 characteristic information acquisition unit 15 calculation unit 20 output unit

Claims

1. A control device for an injection molding machine including a cylinder, a plurality of heaters arranged in an axial direction of the cylinder, and a screw arranged inside the cylinder, an operation information acquisition unit that acquires operation information related to the operation of the heater and the screw; a characteristic information acquisition unit that acquires characteristic information relating to the characteristics of the injection molding machine; a calculation unit that calculates the amount of heat transferred from the heater to the molding material for each of the heater regions divided in the axial direction based on the acquired operation information and characteristic information, and calculates the amount of shear heat generated by the molding material due to the screw operation; an output unit that executes processing to display, on a display device, the amount of heat transfer together with the amount of shear heat generation, as a result of calculation by the calculation unit, for each of a plurality of regions divided in the axial direction.

2. The calculation unit the amount of heat generated by the heater during molding in a state in which the cylinder is maintained at a predetermined set temperature; and the amount of heat generated by the heater when molding is stopped in a state in which the cylinder is maintained at a predetermined set temperature; and 2. The control device for an injection molding machine according to claim 1, wherein the amount of heat transferred from the heater to the molding material is calculated based on the above formula.

3. 3. The control device for an injection molding machine according to claim 1, wherein the calculation unit calculates energy for rotationally driving the screw.

4. 3. The control device for an injection molding machine according to claim 1, wherein the calculation unit calculates the amount of heat transferred within the cylinder for each of a plurality of regions divided in the axial direction.

5. 5. The control device for an injection molding machine according to claim 4, wherein the calculation unit calculates the amount of heat transferred within the cylinder based on the cross-sectional shape of the cylinder, the position and temperature of each cylinder temperature control point, and thermal conductivity.

6. 3. The control device for an injection molding machine according to claim 1, wherein the calculation unit calculates the amount of heat radiation to the outside of the cylinder for each of a plurality of regions divided in the axial direction.

7. The calculation unit The amount of heat transferred within the cylinder; the amount of heat generated by the heater when molding is stopped in a state in which the cylinder is maintained at a predetermined set temperature; and 7. The control device for an injection molding machine according to claim 6, wherein the amount of heat dissipated to the outside of the cylinder is calculated based on the above.

8. the calculation unit calculates a total amount of heat received by the molding material based on the amount of heat transferred from the heater and the amount of shear heat generated; 3. The control device for an injection molding machine according to claim 1, wherein the output unit outputs at least the amount of heat transferred from the heater and the amount of shear heat generated from the heater, among the calculation results of the calculation unit, as a ratio based on the total amount of heat received.

9. The control device for an injection molding machine according to claim 1 or 2, wherein the output unit displays at least one of a table, a bar graph, a pie chart, a band graph, and an energy flow diagram on the display device.

10. A computer that controls an injection molding machine including a cylinder, a plurality of heaters arranged in the axial direction of the cylinder, and a screw arranged inside the cylinder, an operation information acquisition function for acquiring operation information relating to the operation of the heater and the screw; a characteristic information acquisition function for acquiring characteristic information relating to the characteristics of the injection molding machine; a calculation function that calculates the amount of heat transferred from the heater to the molding material for each of the heater regions divided into a plurality of regions in the axial direction based on the acquired operation information and characteristic information, and calculates the amount of shear heat generated by the molding material due to the screw operation; an output function that executes a process of displaying the amount of heat transfer along with the amount of shear heat generation on a display device, distinguishing between multiple regions divided in the axial direction, as the calculation result of the calculation function; and a program that executes the output function.