Rubber composition compounding system, energy efficiency calculation method, and program

Abstract

This invention provides a rubber composition mixing system, an energy efficiency calculation method, and a program capable of calculating the energy efficiency in the mixing process of rubber compositions. [Solution] The control unit 40's control unit 41 includes a work amount acquisition unit 411, a temperature difference calculation unit 412, and an efficiency calculation unit 413. The work amount acquisition unit 411 acquires the amount of work done by the electric motor 30 that rotates the stirring rotor 14. The temperature difference calculation unit 412 acquires the temperature change ΔT of the cooling water used to cool the kneading device 10 before and after cooling. The efficiency calculation unit 413 calculates the energy efficiency, which is the ratio of the energy used for the kneading operation by the stirring rotor 14 to the motor work, based on the temperature change ΔT and the amount of work done by the electric motor 30.

Description

Technical Field

[0001] The present disclosure relates to a rubber composition kneading system for kneading raw rubber and the like, an energy efficiency calculation method for calculating the energy efficiency in the rubber composition kneading system, and a program.

Background Art

[0002] Conventionally, in the production of rubber products such as tires, a closed rubber kneader such as a Banbury mixer is used. In the kneading process by the rubber kneader, a block-shaped raw rubber (polymer) and compounding agents such as carbon, silica, and a silane coupling agent are introduced into the kneading chamber through a raw material input section, and then the kneading chamber is pressurized and kneaded by a rotor rotated by an electric motor. Thereby, a rubber composition (rubber compound) for producing a rubber product such as a tire is obtained.

[0003] In the rubber kneader, in the kneading process of the kneading material containing raw rubber, external forces such as compression, shear (shearing), and friction are applied to the kneading material. Therefore, the kneading material generates heat. If the temperature of the kneading material becomes too high, a decrease in shear force and an excessive decrease in viscosity may occur, resulting in insufficient dispersion of the compounding agent and possible occurrence of dispersion defects. Therefore, the rubber kneading system including the rubber kneader is provided with cooling equipment for cooling the kneading material in the kneading chamber. By this cooling equipment, the kneading material in the kneading chamber is maintained at a temperature at which dispersion defects do not occur.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, if the temperature of the mixing materials in the mixing chamber is low, the viscosity of the mixing materials increases, which increases the load on the electric motor that operates the rotor of the rubber mixing machine, and thus increases the load current. In this case, the ratio of the energy used for the mixing operation by the rotor to the amount of work done by the electric motor decreases, and energy saving cannot be achieved. Furthermore, in recent years, technological advances in silane coupling agents have made it possible to bond more silica to polymers, and in tire manufacturing, there is a tendency to blend more silica and resin into the mixing materials in order to achieve both low fuel consumption and wet grip performance in tires. When the mixing materials become more viscous due to the blending of a large amount of silica, etc., the load on the electric motor increases even further. In addition, the mixing time must be extended in order to more uniformly disperse compounding agents such as silica and resin, making it even more difficult to achieve energy saving.

[0006] The purpose of this disclosure is to provide a rubber composition compounding system, an energy efficiency calculation method, and a program capable of calculating the energy efficiency in the compounding process of a rubber composition. [Means for solving the problem]

[0007] A rubber composition mixing system according to one embodiment of the present disclosure is a rubber composition mixing system that produces a rubber composition by mixing mixing materials, including at least raw rubber, in a mixing device. The rubber composition mixing system includes a first acquisition unit that acquires the amount of temperature change of a cooling medium used to cool the mixing device before and after cooling; a second acquisition unit that acquires the amount of work done by an electric motor that rotates a stirring member provided in the mixing device; and a calculation processing unit that calculates an energy efficiency, which indicates the ratio of energy used for the mixing operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

[0008] An energy efficiency calculation method according to one embodiment of the present disclosure is a method applicable to a rubber composition compounding system for producing a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device. The energy efficiency calculation method is a method in which one or more processors perform the following actions: obtain the amount of temperature change of a cooling medium used to cool the compounding device before and after cooling; obtain the amount of work done by an electric motor that rotates a stirring member provided in the compounding device; and calculate an energy efficiency, which indicates the ratio of energy used for the compounding operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

[0009] A program according to one embodiment of the present disclosure is a program applied to a rubber composition compounding system for producing a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device. The program causes one or more processors to perform the following actions: acquire the amount of temperature change of a cooling medium used to cool the compounding device before and after cooling; acquire the amount of work done by an electric motor that rotates a stirring member provided in the compounding device; and calculate an energy efficiency, which is the ratio of the energy used for the compounding operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

[0010] Another embodiment of the present disclosure is a non-temporary computer-readable recording medium on which the program is stored. [Effects of the Invention]

[0011] According to this disclosure, it is possible to calculate the energy efficiency in the compounding process of a rubber composition. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows the configuration of a rubber compounding system according to an embodiment of this disclosure. [Figure 2] Figure 2 is a longitudinal cross-sectional view showing a cross-section of a rubber compounding apparatus according to an embodiment of this disclosure. [Figure 3]Figure 3 is a cross-sectional view of the section III-III in Figure 2. [Figure 4] Figure 4 is a block diagram showing the configuration of the control unit included in the rubber compounding system. [Figure 5] Figure 5 is a flowchart showing an example of the procedure for calculating energy efficiency performed in a rubber compounding system. [Modes for carrying out the invention]

[0013] The embodiments of this disclosure will be described below with reference to the drawings as appropriate. The embodiments described below are merely examples of the embodiments of this disclosure and do not limit the technical scope of this disclosure.

[0014] Figure 1 shows the configuration of a rubber compounding system 100 according to an embodiment of the present disclosure. The rubber compounding system 100 is an example of a rubber composition compounding system of the present disclosure. The rubber compounding system 100 is used in the manufacture of rubber compositions, which are materials for rubber products such as tires.

[0015] The aforementioned rubber composition is an intermediate product used in the production of the aforementioned rubber product, and is a polymer composition obtained by kneading polymers such as natural rubber or synthetic rubber, and raw materials (compounding materials) such as additives. When this rubber composition is vulcanized, a rubber elastic body having the elasticity characteristic of rubber is formed.

[0016] The polymer is, for example, unvulcanized raw rubber. Examples of the raw rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), and the like.

[0017] The aforementioned additives include, for example, fillers such as carbon black and silica, silane coupling agents, antioxidants, vulcanization accelerators, oils, zinc oxide, stearic acid, sulfur, and processing aids.

[0018] As described above, the rubber elastic body is obtained by vulcanizing the rubber composition, and is used, for example, in the production of tires mounted on vehicles such as automobiles. In the present embodiment, a rubber kneading system 100 for producing the rubber composition, which is a material for tires, will be described by way of example. Note that the rubber kneading system 100 may be used to produce rubber compositions for industrial rubber products such as vibration-damping rubber and medical rubber (medical rubber).

[0019] As shown in FIG. 1, the rubber kneading system 100 includes a kneading device 10, a speed reducer 20, an electric motor 30 (an example of the electric motor of the present disclosure), and a control unit 40 that controls each operation in the rubber kneading system 100.

[0020] [Kneading Device 10] FIG. 2 is a longitudinal sectional view showing a cross section of the kneading device 10 according to an embodiment of the present disclosure, and FIG. 3 is a cross-sectional view of the cutting plane III-III in FIG. 2.

[0021] The kneading device 10 shown in FIGS. 2 and 3 is used in the kneading process, which is a part of the tire manufacturing process. In the present embodiment, in the kneading process by the kneading device 10, a block-shaped polymer, silica, and a silane coupling agent are kneaded to produce a rubber composition. In the kneading process, each material is kneaded until it reaches a uniform mixing state. Note that other additives may be added as necessary.

[0022] In general, the tire manufacturing process includes the kneading process for producing the rubber composition, an extrusion molding process for extruding the rubber composition obtained in the kneading process to form a strip-shaped base rubber, a cutting process for cutting the base rubber into shapes and sizes corresponding to each part of the tire, a molding process for combining plies, beads, sidewall rubber, tread rubber, etc. produced in separate processes to form a local cover, which is a prototype of the tire, and a vulcanization process for heating and vulcanizing the local cover under high pressure.

[0023] In this embodiment, a Banbury mixer, which is a closed-type batch mixer, is exemplified as the mixing device 10. Note that the mixing device 10 shown in Figures 2 and 3 is merely one example of a mixing device capable of mixing polymers and additives, and is not limited to a Banbury mixer. For example, the mixing device 10 may be a closed-type mixing device such as a plunger mixer, ribbon blender, or pressure kneader.

[0024] As shown in Figures 2 and 3, the mixing apparatus 10 comprises a main body 11, a supply unit 12, and an input unit 13. A mixing chamber 111 is formed inside the main body 11. The mixing chamber 111 is a chamber for mixing raw materials. The supply unit 12 is located above the main body 11.

[0025] A connection port 112 is formed at the top of the mixing chamber 111. A supply chamber 121 extending in the vertical direction is formed in the supply section 12. The mixing chamber 111 and the supply chamber 121 are connected to each other via the connection port 112.

[0026] The mixing chamber 111 is provided with a pair of stirring rotors 14 (an example of a stirring member in this disclosure). Each stirring rotor 14 is attached to one of two rotating shafts 15 that extend laterally (horizontally). The two rotating shafts 15 are rotatably supported by bearings provided on the main body 11. One end of each rotating shaft 15 is connected to a reduction gear 20. The output shaft of an electric motor 30 (see Figure 1), which is the drive source, is connected to the reduction gear 20. When the driving force of the electric motor 30 is transmitted to each rotating shaft 15 via the reduction gear 20, each stirring rotor 14 rotates at a predetermined rotational speed. As a result, the rotation of the pair of stirring rotors 14 mixes the raw materials in the mixing chamber 111 and prepares a mixed product.

[0027] An outlet 113 is formed at the bottom of the mixing chamber 111. The mixture mixed in the mixing chamber 111 is discharged to the outside as the rubber composition through the outlet 113. A door 114 is attached to the outlet 113. The door 114 is opened and closed by an actuator (not shown), such as an air cylinder or a hydraulic drive device. When the door 114 is opened, the bottom of the mixing chamber 111 is opened, and when the door 114 is closed, the mixing chamber 111 is sealed. The mixture discharged from the outlet 113 is supplied through a chute (not shown) to an extruder (not shown) used in a later extrusion molding process.

[0028] As described above, a supply chamber 121 is formed in the supply unit 12. The supply chamber 121 is a passage for sending raw materials to the mixing chamber 111. The supply chamber 121 is a cylindrical chamber that extends vertically. The supply unit 12 is provided with an input unit 13 for introducing raw materials into the supply chamber 121. The raw materials introduced from the input unit 13 pass through the supply chamber 121 and are introduced into the mixing chamber 111 through the connection port 112.

[0029] The supply chamber 121 is provided with a floating weight 16 and a shaft 17. The floating weight 16 is mounted on the shaft 17 so as to be movable in the vertical direction. The floating weight 16 is a component that closes the connection port 112. The floating weight 16 is slid vertically by an actuator (not shown), such as an air cylinder or a hydraulic drive device.

[0030] The floating weight 16 is lowered within the supply chamber 121, blocking the connection port 112, thereby sealing the inside of the mixing chamber 111.

[0031] In the mixing process, first, with the floating weight 16 raised above the input section 13, the aforementioned raw materials introduced from the input section 13 are supplied to the mixing chamber 111 of the main body 11. Then, the floating weight 16 is lowered within the supply chamber 121 to close the connection port 112 and seal the mixing chamber 111. Next, the electric motor 30 (see Figure 1) is driven and controlled by the control unit 40, and when the stirring rotor 14 rotates, mixing by the stirring rotor 14 begins. After a predetermined set time has elapsed since the start of mixing, the electric motor 30 is stopped by the control unit 40. The door 114 is opened and the mixed material is discharged.

[0032] During the mixing process, the raw materials are mixed between the wall of the mixing chamber 111 and the stirring rotor 14, generating heat and causing the temperature of the raw materials to rise. The longer the mixing time of the raw materials, the higher the temperature of the raw materials becomes. If the temperature of the raw materials becomes too high during the mixing process, it can lead to a decrease in shear strength and an excessive decrease in viscosity, resulting in insufficient dispersion of the compounding agents and potentially causing poor dispersion. Therefore, as shown in Figure 2, a cooling water jacket 18 is formed inside the main body 11, adjacent to the wall of the mixing chamber 111.

[0033] The cooling water jacket 18 is a cooling water channel formed to surround the mixing chamber 111. Cooling water is supplied to the cooling water jacket 18. The cooling water jacket 18 is formed in the main body 11 to lower the temperature of the raw materials in the mixing chamber 111 and suppress excessive temperature rise. Note that the cooling medium supplied to the cooling water jacket 18 is not limited to cooling water, but may be a liquid other than water that has a cooling effect.

[0034] As shown in Figure 3, the main body 11 is provided with a jacket inlet 10a to which a supply pipe 61 extending from a cooling water supply source is connected, and a jacket outlet 10b to which a drain pipe 62 is connected. The cooling water jacket 18 is a water channel from the jacket inlet 10a to the jacket outlet 10b. The cooling water supplied to the cooling water jacket 18 from the jacket inlet 10a absorbs heat from the raw materials as it passes through the cooling water jacket 18, and is then discharged from the jacket outlet 10b to the drain pipe 62. As a result, the raw materials in the mixing chamber 111 are maintained at a temperature that prevents dispersion failure.

[0035] Incidentally, if the temperature of the raw materials in the mixing chamber 111 is low, the viscosity of the raw materials increases, which increases the load on the electric motor 30 (see Figure 1) that rotates the stirring rotor 14, and thus increases the load current. In this case, the ratio of the energy used for the mixing operation by the stirring rotor 14 to the amount of work done by the electric motor 30 decreases, making it impossible to achieve energy savings. Furthermore, in recent years, advances in silane coupling agents have made it possible to bond more silica to polymers, and in tire manufacturing, there is a tendency to blend more silica and resin into the raw materials in order to achieve both low fuel consumption and wet grip performance in tires. When the viscosity of the raw materials increases due to the blending of a large amount of silica, the load on the electric motor 30 increases even further. In addition, the mixing time must be extended in order to more uniformly disperse compounding agents such as silica and resin, making it even more difficult to achieve energy savings.

[0036] To address these problems, in this embodiment, the control unit 40 is configured as described below, making it possible to calculate the energy efficiency in the raw material mixing process in the mixing device 10, and furthermore, to efficiently control the rotation of the stirring rotor 14 based on the calculated energy efficiency.

[0037] [Control Unit 40] The configuration of the control unit 40 will be described in detail below with reference to Figure 4. Here, Figure 4 is a block diagram showing the configuration of the control unit 40.

[0038] The control unit 40 controls the operation of each device that makes up the rubber compounding system 100. For example, it performs rotor rotation control processing and cooling water flow rate control processing, which control the rotation speed of the stirring rotor 14 in the compounding device 10, as well as energy efficiency calculation processing, which calculates the energy efficiency used in each of these controls.

[0039] As shown in Figure 4, the control unit 40 includes a control unit 41, a storage unit 43, a display unit 44, an operation unit 45, a communication unit 46, and the like.

[0040] The communication unit 46 is a communication interface that connects the control unit 40 to a network and performs data communication with other devices via the network in accordance with a predetermined communication protocol. For example, the control unit 41 outputs the energy efficiency evaluation value obtained by the energy efficiency calculation process to external devices such as display devices on the network, server devices, and the display units of mobile information terminals such as smartphones or tablet terminals via the communication unit 46, and displays them on the display units of each device.

[0041] The memory unit 43 is a non-volatile storage medium that stores various types of information. The memory unit 43 stores programs for the control unit 41 to execute various processes such as the rotor rotation control process, the cooling water flow rate control process, and the energy efficiency calculation process, as well as thresholds and various data used in these processes. The memory unit 43 also stores detected values ​​and data transmitted from the sensors 31, 51, 52, and 53 described later, as well as various types of information (such as motor rotation speed and cooling water flow rate) that have been converted or generated based on the detected values ​​and data.

[0042] The display unit 44 is a liquid crystal display or an organic EL display that displays various information. The control unit 41 displays the energy efficiency evaluation value obtained by the energy efficiency calculation process on the display unit 44.

[0043] The operation unit 45 is a user interface such as a mouse, keyboard, or touch panel that accepts user input. For example, reference values ​​and thresholds used in the rotor rotation control process and the cooling water flow rate control process are input by the user via the operation unit 45.

[0044] The control unit 41 comprises a microcomputer composed of a CPU, ROM, RAM, etc., or a main control board, or a control device such as a PLC. The control unit 41 executes each of the aforementioned processes. The CPU is a processor that executes various processes. The ROM is a non-volatile memory in which programs for causing the CPU to execute various processes are pre-stored. The RAM is a volatile or non-volatile memory that stores various information and is used as a temporary storage memory (work area) for the various processes executed by the CPU. The control unit 41 controls the operation of each part of the rubber compounding system 100 by executing various programs pre-stored in the ROM or storage unit 43 using the CPU.

[0045] The rubber compounding system 100 is equipped with a speed sensor 31, an inlet temperature sensor 51, an outlet temperature sensor 52, a flow rate sensor 53, an electric valve 54, and the like.

[0046] The speed sensor 31 is a sensor for detecting the rotational speed of the electric motor 30. The rotational speed of the electric motor 30 detected by the speed sensor 31 (detected value), or the detection signal indicating the rotational speed, is input to the control unit 41 for rotational speed control.

[0047] The inlet temperature sensor 51 and the outlet temperature sensor 52 are sensors for detecting the temperature of the cooling water flowing through the cooling water jacket 18. In this embodiment, as shown in Figure 1, the inlet temperature sensor 51 is located near the connection point of the supply pipe 61 connected to the jacket inlet 10a, and detects the temperature of the cooling water flowing from the supply pipe 61 toward the jacket inlet 10a. The outlet temperature sensor 52 is located near the connection point of the drain pipe 62 connected to the jacket outlet 10b, and detects the temperature of the cooling water that has flowed from the jacket outlet 10b into the drain pipe 62. The detected temperature (detected value) detected by the inlet temperature sensor 51 and the outlet temperature sensor 52, or the detection signal indicating the detected temperature, is input to the control unit 41.

[0048] The flow sensor 53 is a sensor that detects the amount of cooling water supplied to the cooling water jacket 18. The flow sensor 53 detects the flow rate of the cooling water per unit time (i.e., the flow velocity [L / min]). The flow rate (detected value) detected by the flow sensor 53, or the detection signal indicating the flow rate, is input to the control unit 41.

[0049] The electric valve 54 is a valve device that is opened and closed by electric drive, for example, an electric ball valve. The electric valve 54 is installed in the supply pipe 61. The operation of the electric valve 54 is controlled by the control unit 41. By controlling the valve opening of the electric valve 54 by the control unit 41, the flow rate of cooling water supplied from the cooling water supply source to the cooling water jacket 18 through the supply pipe 61 is adjusted.

[0050] As shown in Figure 4, the control unit 41 includes various processing units such as a work amount acquisition unit 411 (an example of a second acquisition unit in this disclosure), a temperature difference calculation unit 412 (an example of a first acquisition unit in this disclosure), an efficiency calculation unit 413 (an example of a calculation processing unit in this disclosure), a determination unit 414, a rotation control unit 415 (an example of a drive control unit in this disclosure), a flow rate control unit 416 (an example of a flow rate control unit in this disclosure), and an output processing unit 417 (an example of a display processing unit in this disclosure).

[0051] The control unit 41 functions as one of the various processing units by having the CPU execute various arithmetic operations according to the program. The control unit 41 or the CPU is an example of a computer or processor that executes the program. Some or all of the processing units included in the control unit 41 may be composed of electronic circuits. The program may also be a program that causes multiple processors to function as the various processing units.

[0052] The work amount acquisition unit 411 performs a process to acquire the amount of work done by the electric motor 30 that rotates the stirring rotor 14 of the mixing device 10 (hereinafter sometimes referred to as motor work amount). In this embodiment, the motor work amount is acquired while the mixing device 10 is performing the mixing operation in the mixing process.

[0053] The amount of work done by the electric motor 30 [Ws=J] is obtained, for example, by calculating the amount of power supplied to the electric motor 30 while it is in operation, and subtracting the energy loss specific to the electric motor 30 from the amount of power supplied. In other words, the work acquisition unit 411 calculates the amount of power supplied, subtracts the energy loss from the amount of power supplied, and calculates the amount of work done by the electric motor 30.

[0054] The amount of power supplied is calculated based on the supply voltage (input voltage) supplied to the electric motor 30 and the load current (input current) in the electric motor 30. For example, if the electric motor 30 is a DC motor, the amount of power supplied is a value obtained by multiplying the supply voltage by the load current and a predetermined time (for example, the set time described later). If the electric motor 30 is a three-phase AC motor such as a three-phase induction motor, the amount of power supplied is obtained by multiplying the supply voltage, the load current, the power factor of the electric motor 30 by √3, and then multiplying by the predetermined time. Since the power factor fluctuates depending on the motor load, an approximate value may be calculated using, for example, the median value of the fluctuation range of the power factor.

[0055] Energy loss is the sum of copper loss, iron loss, and mechanical loss in the electric motor 30. The energy loss is measured using a value that has been previously determined by a well-known measurement method. This energy loss is stored, for example, in the memory unit 43. The energy loss of a three-phase AC motor can be determined using the calculation method specified in Japanese Industrial Standard JIS C 4034-2-1. Furthermore, iron loss, which accounts for the majority of the energy loss in the electric motor 30, can be determined using the method specified in Japanese Industrial Standard JIS C 2541.

[0056] The work amount acquisition unit 411 acquires, for example, the rotational speed of the electric motor 30 [min -1 The amount of work done by the electric motor 30 may be calculated based on a well-known calculation method using the rotational speed [N·m] and torque [N·m]. Specifically, the work amount acquisition unit 411 calculates the amount of work done by multiplying the rotational speed obtained from the speed sensor 31 by the torque of the output shaft of the electric motor 30, multiplying the resulting power by 2π / 60 (≒0.1047), and then multiplying this power by the predetermined time. Here, the power is the amount of work done per unit time (1 second).

[0057] Furthermore, if the amount of work done by the electric motor 30 has been calculated in advance and stored in the storage unit 43, the work amount acquisition unit 411 may read the amount of work done from the storage unit 43 and acquire it.

[0058] The temperature difference calculation unit 412 performs a process to obtain the temperature change ΔT of the cooling water used to cool the mixing device 10 before and after cooling. In this embodiment, the temperature difference calculation unit 412 calculates the temperature change ΔT by subtracting the inlet temperature T1 detected by the inlet temperature sensor 51 from the outlet temperature T2 detected by the outlet temperature sensor 52 during the mixing operation.

[0059] In another embodiment of the temperature difference calculation unit 412, it is preferable to calculate the temperature change amount ΔT after the temperature rise of the outlet temperature T2 has stabilized, in order to calculate a stable temperature change amount ΔT. When the mixing operation starts, the raw materials in the mixing chamber 111 generate heat and the temperature gradually rises, but the rate of increase decreases over time, and thereafter, due to the cooling effect of the cooling water, the temperature of the raw materials is maintained at a constant temperature. Therefore, it is preferable for the temperature difference calculation unit 412 to periodically detect the outlet temperature T2 and calculate the temperature change amount ΔT when the previously detected value and the currently detected value are approximately the same.

[0060] Furthermore, the temperature difference calculation unit 412 calculates the temperature change ΔT at a predetermined time after the start of the mixing operation. In this case, the time required for the temperature of the raw materials to stabilize is measured by prior experiments, and the setting time is set to the aforementioned time.

[0061] The efficiency calculation unit 413 performs a process to calculate the energy efficiency, which indicates the ratio of energy used for the mixing operation by the stirring rotor 14 to the motor work, based on the temperature change amount ΔT calculated by the temperature difference calculation unit 412 and the amount of work (motor work) of the electric motor 30 acquired by the work amount acquisition unit 411.

[0062] Specifically, the efficiency calculation unit 413 calculates the amount of heat used for cooling based on the temperature change ΔT, the flow rate of the cooling water flowing through the cooling water jacket 18 [L / min], and the specific heat of the cooling water [J / (kg·K)], using a well-known calculation method, and estimates this amount of heat used for cooling as the energy used in the mixing operation. The efficiency calculation unit 413 then calculates the ratio of the amount of heat used for cooling to the amount of motor work acquired by the work acquisition unit 411 as the energy efficiency.

[0063] Here, if we denote the motor work as P [Ws=J], the cooling heat as Q [kW], and the energy efficiency as h, then, neglecting the amount of heat dissipated into the atmosphere, the following relationship (1) holds between them.

[0064] h = Q / P ... (1)

[0065] For example, if the flow rate of the cooling water is R [L / min] and the specific heat of the cooling water is C [J / (kg·K)], the amount of cooling heat Q after the set time (unit: hours (hr.)) has elapsed can be calculated by the following formula (2). Formula (1) is stored in the memory unit 43, and the efficiency calculation unit 413 applies the flow rate detected by the flow sensor 53, the temperature change ΔT calculated by the temperature difference calculation unit 412, and the specific heat C to formula (2) to calculate the amount of cooling heat Q.

[0066] Q = ΔT × R × 60 × C × 10 -3 [kW] ... (2)

[0067] The determination unit 414 determines whether the energy efficiency h calculated by the efficiency calculation unit 413 is less than a predetermined reference value. The reference value is a threshold value for determining whether the energy efficiency is low, and is a value obtained in advance through experiments or other means. If the energy efficiency h is equal to or greater than the reference value, the determination unit 414 determines that the energy efficiency is good. On the other hand, if the energy efficiency h is less than the reference value, the determination unit 414 determines that the energy efficiency is not good and that energy saving has not been achieved.

[0068] The rotation control unit 415 controls the rotational drive of the electric motor 30. The rotation control unit 415 also controls the rotational drive of the electric motor 30 according to the energy efficiency h calculated by the efficiency calculation unit 413.

[0069] Specifically, the rotation control unit 415 increases the rotation speed of the electric motor 30 in order to increase the rotation speed of the stirring rotor 14 beyond a predetermined specified speed when it is determined that the energy efficiency h is less than the reference value. For example, the rotation control unit 415 may increase the rotation speed of the stirring rotor 14 beyond the specified speed by a predetermined increase amount, or it may increase the rotation speed of the stirring rotor 14 beyond the specified speed by an increase amount corresponding to the difference from the reference value.

[0070] The flow rate control unit 416 controls the flow rate of cooling water supplied to the cooling water jacket 18. The flow rate control unit 416 also controls the flow rate of cooling water supplied to the cooling water jacket 18 according to the energy efficiency h calculated by the efficiency calculation unit 413.

[0071] Specifically, when the flow control unit 416 determines that the energy efficiency h is less than the reference value, it operates the electric valve 54 to reduce the opening of the electric valve 54, thereby lowering the flow rate of the cooling water to a predetermined specified flow rate. For example, the flow control unit 416 may reduce the opening of the electric valve 54 by a predetermined angle, or by an angle corresponding to the difference from the reference value.

[0072] The reference value used for speed increase control of the rotation control unit 415 (an example of the first reference value in this disclosure) and the reference value used for flow rate control of the flow rate control unit 416 (an example of the second reference value in this disclosure) may be the same value, or they may be different values. These reference values ​​can be set arbitrarily.

[0073] The output processing unit 417 performs the process of outputting the energy efficiency h calculated by the efficiency calculation unit 413 to a predetermined display device. For example, the output processing unit 417 outputs the energy efficiency h to the display unit 44 in order to display it on the display unit 44. Alternatively, the output processing unit 417 may output the control unit 40 to a network-connected display device, server device, smartphone or tablet terminal or other portable information terminal, and have the energy efficiency h displayed on the display unit of each of these devices.

[0074] [Energy efficiency calculation process] The energy efficiency calculation method of this disclosure will be described below, along with an example of the procedure for the energy efficiency calculation process performed in the rubber compounding system 100, with reference to the flowchart in Figure 5. The energy efficiency calculation process performed by the control unit 41 of the control unit 40 will be described below. Here, the energy efficiency calculation process includes a rotation speed control process that controls the rotation speed of the stirring rotor 14 based on the calculated energy efficiency, a flow rate control process that controls the flow rate of the wastewater supplied to the cooling water jacket 18 based on the calculated energy efficiency, and a display process that displays the calculated energy efficiency.

[0075] One or more steps included in the energy efficiency calculation process described below may be omitted as appropriate. Furthermore, the execution order of each step in the energy efficiency calculation process may differ to the extent that similar effects are produced.

[0076] As shown in Figure 5, when the mixing operation in the mixing process is started, the control unit 41 determines in step S11 whether the outlet temperature T2 is above a predetermined set temperature. When the mixing operation is started, the temperature of the raw materials in the mixing chamber 111 gradually rises. In step S11, it is determined that the raw materials are generating heat because the cooling water temperature rises above the set temperature due to the heat from the raw materials. The set temperature is set to a temperature at which the heat generation of the raw materials can be confirmed, for example, a predetermined temperature (e.g., 10°C) higher than the inlet temperature T1.

[0077] If, in step S11, the outlet temperature T2 is determined to be equal to or greater than the set temperature, then in the next step S12, the control unit 41 determines whether the outlet temperature T2 has stabilized. The control unit 41 periodically detects the outlet temperature T2, and when the detected temperature stops changing, specifically when the temperature change of the outlet temperature T2 is within an acceptable range, the control unit 41 determines that the outlet temperature T2 has stabilized and will not rise any further.

[0078] If it is determined in step S12 that the outlet temperature T2 has stabilized, in the next step S13, the control unit 41 calculates the temperature change ΔT of the cooling water flowing through the cooling water jacket 18. This process is performed by the temperature difference calculation unit 412 described above. Step S13 is a step in which the temperature change ΔT of the cooling water before and after cooling is obtained.

[0079] Furthermore, in the next step S14, the control unit 41 calculates the amount of work (motor work) of the electric motor 30. This process is performed by the work amount acquisition unit 411 described above. Step S14 is a step in which the amount of work of the electric motor 30 is acquired.

[0080] In the next step S15, the control unit 41 calculates the energy efficiency h based on the temperature change ΔT and the motor work. This process is performed by the efficiency calculation unit 413 described above. Step S15 is the step for calculating the energy efficiency h.

[0081] In the next step S16, the control unit 41 performs a process to display the calculated energy efficiency h on the display unit 44 of the control unit 40 or on the display unit of an external device. This process is performed by the output processing unit 417 described above.

[0082] In step S17, the control unit 41 determines whether the calculated energy efficiency h is less than the reference value. This determination process is performed by the determination unit 414 described above. If the energy efficiency h is less than the reference value, the process proceeds to step S18. If the energy efficiency h is equal to or greater than the reference value, the process proceeds to step S20.

[0083] Furthermore, if the energy efficiency h is less than the reference value, it can be said that the utilization efficiency of the motor work supplied from the electric motor 30 to the mixing device 10 is not good. Therefore, in steps S18 and S19 following step S17, the rotational speed of the electric motor 30 and the amount of cooling water supplied are controlled to improve the utilization efficiency of the motor work.

[0084] In step S18, the control unit 41 performs a process (rotation control process) to increase the rotational speed of the electric motor 30 if the calculated energy efficiency h is less than the reference value. This increases the rotational speed of the stirring rotor 14. This process is performed by the rotation control unit 415 described above.

[0085] The amount of heat generated by the raw materials in the mixing chamber 111, which are to be stirred, is proportional to the value obtained by multiplying the energy efficiency h by the rotational speed of the stirring rotor 14. Therefore, if the energy efficiency h is less than the reference value, the temperature of the raw materials in the mixing chamber 111 will not be sufficiently heated to the target temperature, the viscosity of the raw materials will not decrease, the load on the electric motor 30 that rotates the stirring rotor 14 will increase, and the load current will increase. For this reason, in this embodiment, in step S18, if the energy efficiency h is less than the reference value, energy consumption can be suppressed by increasing the rotational speed of the electric motor 30.

[0086] Furthermore, in step S19, if the calculated energy efficiency h is less than the reference value, the control unit 41 operates the electric valve 54 to reduce the opening degree of the electric valve 54 (flow rate control process). This reduces the amount of cooling water supplied to the cooling water jacket 18 and suppresses the flow rate of the cooling water. This process is performed by the flow rate control unit 416 described above.

[0087] If the energy efficiency h is less than the reference value, the temperature of the raw materials in the mixing chamber 111 may not be sufficiently heated, and the viscosity of the raw materials may not decrease, maintaining a high viscosity state. In this case, in order to prevent the heating rate from becoming too low, it is preferable to reduce the cooling effect of the cooling water and raise the temperature of the raw materials to the target temperature as quickly as possible. Therefore, in this embodiment, in step S19, if the energy efficiency h is less than the reference value, the opening degree of the electric valve 54 is reduced. This suppresses excessive cooling and promotes the heating of the raw materials.

[0088] Note that steps S18 and S19 may both be performed, or only one of them may be performed.

[0089] In step S20, the control unit 41 determines whether the mixing operation has finished. For example, if a preset mixing time has elapsed or a signal to stop the mixing operation is received, the control unit 41 terminates the mixing operation and the series of energy efficiency calculation processes are completed. On the other hand, if the mixing operation has not finished and needs to be continued, the control unit 41 returns to step S13 and executes the processes from step S13 onward.

[0090] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. The above-described embodiments include the following disclosures. Note that each configuration and each processing function of the following disclosures can be selected and combined as desired.

[0091] <Disclosure Item 1> A rubber composition compounding system for producing a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, A first acquisition unit that acquires the amount of temperature change of the cooling medium used to cool the mixing apparatus before and after cooling, A second acquisition unit acquires the amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing apparatus, A rubber composition mixing system comprising: a calculation processing unit that calculates an energy efficiency indicating the ratio of energy used for the mixing operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

[0092] <Disclosure Item 2> The rubber composition mixing system according to Disclosure 1, wherein the calculation processing unit calculates the amount of heat used for cooling as the energy used for the mixing operation based on the amount of temperature change, the flow rate of the cooling medium, and the specific heat of the cooling medium, and calculates the ratio of the amount of heat used for cooling to the amount of work as the energy efficiency.

[0093] <Disclosure Item 3> The rubber composition compounding system according to disclosure 1 or 2, further comprising a drive control unit that controls the rotational drive of the electric motor in accordance with the energy efficiency calculated by the calculation processing unit.

[0094] <Disclosure Item 4> The rubber composition mixing system according to disclosure 3, wherein the drive control unit increases the rotational speed of the stirring member when the energy efficiency falls below a predetermined first reference value.

[0095] <Disclosure Item 5> The rubber composition mixing system according to any one of disclosures 1 to 4, further comprising a flow rate control unit that controls the flow rate of the cooling medium according to the energy efficiency calculated by the calculation processing unit.

[0096] <Disclosure Item 6> The rubber composition mixing system according to disclosure 5, wherein the flow rate control unit reduces the flow rate of the cooling medium when the energy efficiency falls below a predetermined second reference value.

[0097] <Disclosure Item 7> A rubber composition mixing system according to any one of disclosures 1 to 6, further comprising a display processing unit that outputs the energy efficiency calculated by the calculation processing unit to a predetermined display device.

[0098] <Disclosure Item 8> An energy efficiency calculation method applicable to a rubber composition compounding system that manufactures a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, The temperature change of the cooling medium used to cool the aforementioned mixing apparatus is obtained before and after cooling. The amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing device is obtained. An energy efficiency calculation method in which one or more processors perform the calculation of an energy efficiency that indicates the ratio of energy used for the mixing operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

[0099] <Disclosure Item 9> A program applicable to a rubber composition compounding system that manufactures a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, The temperature change of the cooling medium used to cool the aforementioned mixing apparatus is obtained before and after cooling. The amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing device is obtained. A program for causing one or more processors to calculate an energy efficiency, which is the ratio of the energy used for the mixing operation by the stirring member to the amount of work, based on the temperature change and the amount of work. [Explanation of Symbols]

[0100] 10:Kneading device 10a: Jacket entrance 10b: Jacket exit 11: Main body 12: Supply section 13: Feeding section 14: Stirring rotor 15: Rotation axis 16: Floating weight 17: Shaft 18: Cooling water jacket 20: Reducer 30: Electric motor 31: Speed ​​sensor 40: Control Unit 41: Control Unit 43: Storage section 44: Display section 45:Operation unit 46: Communications Department 51: Inlet temperature sensor 52: Outlet temperature sensor 53: Flow sensor 54: Electric valve 61: Supply pipe 62: Drain pipe 100: Rubber compounding system 111: Mixing Room 112: Connection port 113: Outlet 114: Door 121: Supply room 411: Workload Acquisition Department 412: Temperature difference calculation section 413: Efficiency calculation unit 414: Judgment section 415: Rotation control unit 416: Flow Control Unit 417: Output Processing Unit

Claims

1. A rubber composition compounding system for producing a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, A first acquisition unit that acquires the amount of temperature change of the cooling medium used to cool the mixing apparatus before and after cooling, A second acquisition unit acquires the amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing apparatus, A rubber composition mixing system comprising: a calculation processing unit that calculates an energy efficiency indicating the ratio of energy used for the mixing operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

2. The rubber composition mixing system according to claim 1, wherein the calculation processing unit calculates the amount of heat used for cooling as the energy used for the mixing operation based on the amount of temperature change, the flow rate of the cooling medium, and the specific heat of the cooling medium, and calculates the ratio of the amount of heat used for cooling to the amount of work as the energy efficiency.

3. The rubber composition mixing system according to claim 1, further comprising a drive control unit that controls the rotational drive of the electric motor in accordance with the energy efficiency calculated by the calculation processing unit.

4. The rubber composition mixing system according to claim 3, wherein the drive control unit increases the rotational speed of the stirring member when the energy efficiency falls below a predetermined first reference value.

5. The rubber composition mixing system according to claim 1, further comprising a flow rate control unit that controls the flow rate of the cooling medium according to the energy efficiency calculated by the calculation processing unit.

6. The rubber composition mixing system according to claim 5, wherein the flow rate control unit reduces the flow rate of the cooling medium when the energy efficiency falls below a predetermined second reference value.

7. The rubber composition mixing system according to claim 1, further comprising a display processing unit that outputs the energy efficiency calculated by the calculation processing unit to a predetermined display device.

8. A method for calculating energy efficiency applicable to a rubber composition compounding system that manufactures a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, The temperature change of the cooling medium used to cool the aforementioned mixing apparatus is obtained before and after cooling. The amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing device is obtained. An energy efficiency calculation method in which one or more processors perform the calculation of an energy efficiency that indicates the ratio of energy used for the mixing operation by the stirring member to the amount of work, based on the amount of temperature change and the amount of work.

9. A program applicable to a rubber composition compounding system that manufactures a rubber composition by compounding compounding materials, including at least raw rubber, in a compounding device, The temperature change of the cooling medium used to cool the aforementioned mixing apparatus is obtained before and after cooling. The amount of work done by the electric motor that rotates the stirring member of the aforementioned mixing device is obtained. A program for causing one or more processors to calculate an energy efficiency, which is the ratio of the energy used for the mixing operation by the stirring member to the amount of work, based on the temperature change and the amount of work.

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