Method for evaluating kneading state, and kneader

Abstract

To provide a kneading state evaluation method capable of ascertaining a change in a physical property of a kneading material in a sealed kneader having a pair of rotors, and a kneader.SOLUTION: An evaluation method of a kneading state is an evaluation method in a sealed kneader 1 having a pair of rotors connected by a pair of gears and rotated by driving an electric motor. In the evaluation method, kneading parameters such as a temperature of a kneading material, a pressure of a pressurizing lid of the kneader, an effective value of an AC current supplied to the motor, a DC current value supplied to the motor, a power consumed by the motor, a load factor of the motor, an output torque of the motor, the number of rotations per one minute of the rotor, or an angular velocity of the rotor are repeatedly sampled and obtained; and subsequently a moving average of a predetermined freely selected time span of an acquired input value, a variance of a freely selected time span, a standard deviation of a freely selected time span, a deviation between the input value and the moving average of the freely selected time span, or a value processed from resulting values, or a combination of resulting values, is used as an evaluation index.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a method for evaluating a mixing state when materials such as rubber, plastics, and ceramics are mixed by a mixer, for example, in a batch manner, and to a mixer. [Background technology]

[0002] Conventionally, a closed type kneader is known as a device for kneading various materials (for example, see Patent Document 1). In this closed type kneader, after the materials are charged into a kneading tank, the materials are kneaded by rotating two kneading rotors. Generally, as kneading rotors for closed type kneaders, there are known an intermeshing type rotor in which two kneading rotors rotate so as to intermesh with each other, and a tangential type (non-intermeshing type) rotor.

[0003] Here, an example of a closed type kneader equipped with a tangential rotor is shown in Fig. 15. Fig. 15 is a schematic plan view of the kneader. In Fig. 15, a closed type kneader 21 has a kneading tank 22, two kneading rotors 23A and 23B arranged side by side in the kneading tank 22, bearings 26A and 26B that rotatably support rotor shafts 25A and 25B of the kneading rotors 23A and 23B, and a pair of gears 27A and 27B. Spiral blades 24a and 24b are formed on the outer periphery of the kneading rotors 23A and 23B, respectively.

[0004] In Fig. 15, one of the rotor shafts 25A and 25B (for example, 25A) is connected to a driving means such as a motor, and the other rotor shaft (for example, 25B) is connected to the one rotor shaft via a pair of gears 27A and 27B. By driving the rotor shaft 25A to rotate with the driving means, the kneading rotors 23A and 23B rotate and knead the material to be kneaded. In this case, the kneading rotor 23A connected to the driving means corresponds to the driving rotor, and the kneading rotor 23B corresponds to the driven rotor.

[0005] In a closed-type mixer with tangential rotors as shown in Fig. 15, a speed difference of about 15% to 25% is generally provided between the driving rotor and the driven rotor by changing the gear ratio of a pair of gears. By rotating these mixing rotors at different speeds, the phase of the driving rotor and the driven rotor changes, and mixing is performed evenly. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-313916 [Patent Document 2] International Publication No. 2021 / 033390 Summary of the Invention [Problem to be solved by the invention]

[0007] Conventionally, in a tangential rotor hermetic mixer, the end of mixing is determined using the following indicators: (1) mixing time, (2) temperature of the material to be mixed, (3) power consumption, or a combination of these. For example, the temperature of the material to be mixed increases as mixing progresses. When the temperature of the material to be mixed is used as an indicator, the timing of the end of mixing is determined, for example, when the temperature reaches a predetermined temperature. However, the above indicators that have been used conventionally mainly indicate the amount of energy input during mixing, and it is difficult to grasp the change in the physical properties of the material to be mixed during mixing.

[0008] Recently, a system has been proposed as a judgment system for judging the state of an object to be stirred, which includes an acquisition unit that acquires waveform data indicating a waveform related to a current supplied to a drive unit of an agitator having a mechanism unit for stirring an object to be stirred and a drive unit for driving the mechanism unit, and a judgment unit that judges the state of the object to be stirred based on a change resulting from a component of a specific direction of a force applied to the drive unit, which is obtained from the waveform data (see Patent Document 2). In Patent Document 2, the current supplied to the drive unit is an AC current having a reference frequency, and the technology uses waveform data of the AC current, that is, an instantaneous value of the AC current. Specifically, an instantaneous value waveform of the AC current, which is a sine wave, is input, and the state of the object to be stirred is judged by focusing on the component of the reference frequency output and other components. Thus, a new method for grasping the change in the physical properties of the material to be kneaded during kneading is required.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a method for evaluating the mixing state in an enclosed mixer with a pair of rotors, which can grasp changes in the physical properties of the material to be mixed, and a mixer. [Means for solving the problem]

[0010] One embodiment of the method for evaluating the kneaded state of the present invention is a method for evaluating the kneaded state in a kneader having a pair of rotors connected by a pair of gears and rotated by the drive of an electric motor, and the evaluation method is characterized in that it repeatedly samples and acquires the temperature of the material to be kneaded, the pressure of a pressure lid in the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor, and uses as an evaluation index a moving average of a predetermined arbitrary time width, a variance of an arbitrary time width, a standard deviation of an arbitrary time width, a deviation between the input value and the moving average of an arbitrary time width, or processed values ​​of these, or a combination of these.

[0011] Here, a series of data in which the input values ​​obtained by the above repeated sampling are recorded in the order of sampling time together with the sampling time is called time series data. In particular, input values ​​obtained by sampling and recorded directly are called original time series data. The above evaluation method includes a mode in which the accumulated data is analyzed and evaluated later, as well as a mode in which the kneader is monitored in real time. As described above, the concept of "using as an evaluation index" is not limited to the case where the above is directly used as an evaluation index, but also includes the case where a value obtained by processing the above (for example, a value obtained by first-order differentiation of a moving average of a predetermined arbitrary time width, a value obtained by second-order or higher order differentiation, a value processed by a low-pass filter, and a combination of these, etc.) is used as an evaluation index. Time series data including the above processed values ​​is called derived time series data.

[0012] In the above kneader, the pair of rotors are tangential rotors, the gears have different integer numbers of teeth, and the pair of rotors rotate at different speeds, and the evaluation method uses, as the arbitrary time width, a period immediately preceding the current time of the input value until the pair of rotors return to the same phase, and uses, as an evaluation index, a moving average of the period, a variance of the period, a standard deviation of the period, a deviation between the input value and the moving average of the period, or a combination of these.

[0013] In the case where the rotation speed of the pair of rotors in the kneader changes midway, the arbitrary time width is changed in accordance with the change in the rotation speed, and a moving average of the changed time width, a variance of the changed time width, a standard deviation of the changed time width, a deviation between the input value and the moving average of the changed time width, or a combination of these is calculated. For example, the changed time width may be a period until one of the pair of rotors rotates a certain number of times after the rotation speed has changed.

[0014] In another embodiment, the method for evaluating the kneaded state of the present invention is a method for evaluating the kneaded state in a kneader having a pair of rotors connected by a pair of gears and rotated by the drive of an electric motor, and the evaluation method is characterized in that the temperature of the material to be kneaded, the pressure of the pressure lid of the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor are repeatedly sampled and acquired, and the moving average of the acquired input values ​​for a predetermined arbitrary number of rotations of one of the rotors (e.g., the driving rotor), the variance for an arbitrary number of rotations, the standard deviation for an arbitrary number of rotations, the deviation between the input value and the moving average for an arbitrary number of rotations, or processed values ​​of these, or a combination of these, is used as the evaluation index.

[0015] The end timing is determined based on the variance, the standard deviation, or the deviation being equal to or smaller than a determination threshold. The end timing may also be determined based on the input value at the current time falling within a range of 80% to 120% of the moving average for a predetermined period of time.

[0016] The kneading machine is characterized in that it is a kneading machine for kneading non-Newtonian fluids, specifically, rubber, plastics, ceramics, silicone, chewing gum compositions, and the like.

[0017] In one embodiment, the kneader of the present invention is a kneader having a pair of rotors connected by a pair of gears and rotated by the drive of an electric motor, and is characterized in that the kneader has an acquisition unit that repeatedly samples and acquires the temperature of the material to be kneaded, the pressure of the pressure lid in the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor, and a calculation unit that calculates a moving average of a predetermined arbitrary time width, a variance of an arbitrary time width, a standard deviation of an arbitrary time width, a deviation between the input value and the moving average of an arbitrary time width, or values ​​obtained by processing these, or a combination of these, of the input values ​​acquired by the acquisition unit.

[0018] In the above kneader, the pair of rotors are tangential rotors, the gears have different integer numbers of teeth, and the pair of tangential rotors rotate at different speeds, and the calculation unit uses, as the arbitrary time width, a period immediately preceding the current time of the input value until the pair of rotors return to the same phase, and calculates a moving average of the period, a variance of the period, a standard deviation of the period, a deviation between the input value and the moving average of the period, or a combination of these.

[0019] In the case where the rotation speed of the pair of rotors in the kneader changes midway, the calculation unit changes the arbitrary time width in accordance with the change in the rotation speed, and calculates a moving average of the changed time width, a variance of the changed time width, a standard deviation of the changed time width, a deviation between the input value and the moving average of the changed time width, or a combination of these.

[0020] In another embodiment, the kneader of the present invention is a kneader having a pair of rotors connected by a pair of gears and rotated by driving an electric motor, the kneader having an acquisition unit that repeatedly samples and acquires the temperature of the material to be kneaded, the pressure of the pressure lid in the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor, and a calculation unit that calculates a moving average of the input values ​​acquired by the acquisition unit for a predetermined arbitrary number of rotations of one of the rotors, a variance for an arbitrary number of rotations, a standard deviation for an arbitrary number of rotations, a deviation between the input value and the moving average for an arbitrary number of rotations, or values ​​processed from these, or a combination of these.

[0021] The present invention is characterized in that it has a determination unit that determines the end timing based on the variance, the standard deviation, or the deviation calculated by the calculation unit being equal to or less than a determination threshold.Furthermore, it may have a determination unit that determines the end timing based on the value of the input value at a current time falling within a range of 80% to 120% of the moving average calculated by the calculation unit for a predetermined period of time. Effect of the Invention

[0022] A method for evaluating the kneaded state according to one embodiment of the present invention is a method for evaluating the kneaded state in a kneader having a pair of rotors connected by a pair of gears and rotated by the drive of an electric motor. In this evaluation method, the temperature of the material to be kneaded, the pressure of the pressurizing lid in the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor are repeatedly sampled and acquired, and the moving average of the acquired input values ​​over a predetermined arbitrary time width, the variance of an arbitrary time width, the standard deviation of an arbitrary time width, the deviation between the input value and the moving average of an arbitrary time width, or a value obtained by processing these, or a combination of these, is used as an evaluation index, so that the change in physical properties such as the viscosity, dispersion, and uniformity of the material to be kneaded during kneading can be well understood. For example, by accurately understanding the timing of the end of a batch process, the effects of improving the stability of physical properties between batches, improving productivity per hour, and reducing energy consumption by preventing excessive energy input can be considered.

[0023] In particular, in a kneading machine in which the pair of rotors are tangential rotors and are configured to rotate at different speeds, by using as an evaluation index the moving average of the period until the pair of rotors return to the same phase immediately prior to the current time of the input value, the variance of the period, the standard deviation of the period, the deviation between the input value and the moving average of the period, or a combination of these, it becomes easier to more accurately grasp the state of each cycle in which the pair of rotors return to the same phase, which ultimately leads to a good understanding of the changes in the physical properties of the material being kneaded during kneading.

[0024] In another embodiment of the method for evaluating the kneading state of the present invention, each parameter is repeatedly sampled and acquired, and the moving average of the acquired input value for a predetermined arbitrary number of rotations of one rotor, the variance for the arbitrary number of rotations, the standard deviation for the arbitrary number of rotations, the deviation between the input value and the moving average for the arbitrary number of rotations, or a value obtained by processing these, or a combination of these, is used as an evaluation index, so that the change in physical properties such as the viscosity, dispersion, and uniformity of the kneading material during kneading can be well understood, and by using the number of rotations as an axis (reference), it becomes easier to more accurately understand the state of each cycle in which the pair of rotors return to the same phase, which leads to a good understanding of the change in physical properties of the kneading material during kneading. It can also deal with changes in the rotation speed of the rotors.

[0025] The end timing is determined based on the variance, standard deviation, or deviation being below the judgment threshold, i.e., the variation in input values ​​(such as temperature and power values) becoming smaller, so that the end timing of kneading can be determined quickly and accurately. [Brief description of the drawings]

[0026] [Figure 1] 1 is an explanatory diagram showing a schematic overall configuration of a kneader according to the present invention. [Diagram 2] FIG. 2 is a diagram for explaining the driving of the kneading rotor of the kneader of FIG. [Diagram 3] FIG. 4 is a diagram showing an example of the number of teeth of a pair of gears. [Figure 4] 10 is a flowchart illustrating an example of a process executed by a control unit. [Diagram 5] This is an illustration of how the simple moving average SMA is calculated. [Figure 6] 1 is a graph showing the temporal fluctuations of each parameter in the conventional technology. [Figure 7] 4 is a graph showing the temporal variation of each parameter in the present invention. [Figure 8] 4 is a graph showing the temporal variation of each parameter in the present invention. [Figure 9] 13 is a graph showing temporal fluctuations of power values ​​after processing of another moving average. [Figure 10] 11 is a graph showing temporal fluctuations in power values ​​after low-pass filtering; [Figure 11] This is a graph in which each smoothing process is superimposed. [Figure 12] 1 is a graph showing the temporal fluctuations of each parameter in the present invention and the prior art. [Figure 13] 13 is a graph showing an example of obtaining extreme values ​​(maximum and minimum values). [Figure 14] 11 is a graph showing an example of obtaining an inflection point. [Figure 15] FIG. 1 is a diagram for explaining the driving of a kneading rotor of a conventional kneader. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The kneader used in the kneading state evaluation method of the present invention is a closed type kneader for kneading non-Newtonian fluids including rubber, plastic, etc. Fig. 1 is an explanatory diagram showing a schematic overall configuration of the kneader according to the present invention, and mainly shows a schematic cross-sectional view of the kneading tank located at the lower end of the kneader.

[0028] As shown in Fig. 1, the closed type mixer 1 mainly comprises a mixer mechanism including a mixer tank 2 and an electric motor 8 (see Fig. 2), a pressurizing mechanism including a pressurizing lid 9a for pressurizing the material put into the mixer tank, and a control unit 12 for controlling the mixing of the material. The evaluation method and mixer of the present invention are characterized in that the mixer parameters detected by a sensor or the like are repeatedly sampled and acquired, and the calculated values ​​obtained by performing a predetermined arithmetic process on the acquired input values ​​are used as the evaluation index. Specifically, parameters indicating the variation of the input values, such as the average value, variance, and standard deviation, over a predetermined arbitrary time span or arbitrary number of rotor rotations are used as the evaluation index.

[0029] The kneading tank 2 has an inner peripheral surface shape like two roughly C-shaped partial peripheral surfaces connected facing each other, and has two rotor chambers 2A, 2B adjacent to each other and communicating inside. A mountain-shaped edge wall 2C is formed at the boundary between the inner peripheral surfaces of the rotor chambers 2A, 2B at the inner bottom of the kneading tank 2. Both axial ends of each rotor chamber 2A, 2B are closed by respective tank end walls (not shown). The cross-sectional shape of the rotor chambers 2A, 2B is constant in the axial direction.

[0030] The closed mixer 1 has a temperature sensor 10 that detects the temperature in the mixer tank during mixing. The temperature sensor 10 is arranged so that the detection end 10a protrudes from the upper surface of the rear wall portion 2C, and is capable of detecting the temperature of the material to be mixed that comes into contact with the detection end 10a. A known temperature sensor is used for the temperature sensor 10, for example, a thermocouple temperature detector that measures temperature by housing a thermocouple element in a protective tube. For example, the thermocouple temperature detector may be a grounded type in which the tip of the thermocouple element is welded to the tip of the protective tube and the temperature of the material to be mixed is detected on the outer surface of the protective tube, or a non-grounded type in which the thermocouple element is insulated from the protective tube and the temperature inside the protective tube is detected.

[0031] The temperature sensor provided in the closed mixer 1 may be any sensor capable of detecting the temperature of the material to be mixed during mixing, and is not limited to the sensor configuration or arrangement shown in Fig. 1. The temperature change of the material to be mixed detected by the temperature sensor will be described later.

[0032] As shown in FIG. 1, kneading rotors 3A and 3B for kneading the material are rotatably arranged in the rotor chambers 2A and 2B at a distance from the inner circumferential surface of the rotor chambers 2A and 2B. The kneading rotors 3A and 3B each have a plurality of blades 4a and 4b (two in FIG. 1). The blades 4a and 4b each have a cross-sectional shape that is mountain-shaped from the starting end side to the terminal end side, and have a land portion at the top. This land portion rotates while maintaining a predetermined distance from the inner circumferential surface. The shape of the kneading space in the rotor chambers 2A and 2B changes as the kneading rotors 3A and 3B rotate in different directions. The kneading rotors 3A and 3B are configured to rotate in different directions, and the blade rotates downward on the side where the rotor chambers 2A and 2B communicate with each other.

[0033] An opening is provided above the kneading tank 2 for introducing the material to be kneaded. The pressurizing lid 9a can be moved up and down by a cylinder device or the like, and the material to be kneaded is introduced through the opening while the pressurizing lid 9a is raised. The pressurizing lid 9a is then lowered by the rod 9b, and the two kneading rotors 3A and 3B are rotated while pressurizing the material to be kneaded. In this case, the helical blades 4a and 4b knead the material to be kneaded by flowing in complex directions including not only the rotational direction of the rotors but also the axial direction.

[0034] The kneader according to the present invention is not limited to the configuration shown in Fig. 1. The closed kneader 1 in Fig. 1 is of a type in which the kneading material is taken out from the opening by inverting the kneading tank 2 after kneading, but for example, the kneader may be of a type in which the kneading material is taken out from the lower part of the kneading tank after kneading. In addition, the closed kneader 1 in Fig. 1 is of a type called a tangential type in which the areas where the kneading rotors 3A and 3B rotate do not overlap, but it may be of a type called an intermeshing type in which the kneading rotors 3A and 3B rotate at the same speed and the areas where they rotate overlap.

[0035] FIG. 2 shows a schematic plan view of the closed type mixer. As shown in FIG. 2, the closed type mixer 1 has the above-mentioned mixing tank 2, the mixing rotors 3A and 3B, the bearings 6A and 6B that rotatably support the rotor shafts 5A and 5B, and a pair of gears 7A and 7B. The blades 4a and 4b formed in a spiral shape are formed on the outer periphery of the mixing rotors 3A and 3B. For example, in the mixing rotor 3A, the blades 4a and 4b have their starting ends at positions at both axial ends of the mixing rotor 3A where the phases in the circumferential direction are different from each other by 180°, and extend from these starting ends in the spiral direction on the outer circumferential surface of the mixing rotor 3A. The configuration of the blades in the mixing rotor is not limited to this. In FIG. 2, the blades 4a and 4b have different lengths in the spiral direction, and the blade 4a is a long blade and the blade 4b is a short blade. The number of blades is not limited to two, and three, four, six, etc. can be adopted. In this case, for example, the positions of the starting ends between the blades (phase in the circumferential direction) are appropriately set according to the number of blades.

[0036] In the closed type kneader 1, the rotor shafts 5A and 5B of the two kneading rotors 3A and 3B are arranged in parallel. The rotor shaft 5A is connected to the output shaft 5A' of the electric motor 8 via a coupling 17. The coupling 17 may be omitted and the rotor shafts 5A and 5A' may be integrally configured. On the other hand, the rotor shaft 5B is connected to the rotor shaft 5A via a pair of gears 7A and 7B. The electric motor 8 has a circuit section 8a and a motor section 8b. The circuit section 8a generates electric power based on a control signal and supplies the generated electric power to the motor section 8b. The electric motor 8 has a power sensor 11 that detects the electric power supplied to the motor section 8b. In the present invention, the electric motor may be an AC motor driven by an AC power source or a DC motor driven by a DC power source.

[0037] The electric motor 8 may be equipped with a reduction gear, and may be configured to reduce the rotational force generated by the drive source before outputting it. The pair of gears 7A, 7B is not limited to gears provided outside the electric motor 8 as shown in FIG. 2, but may be gears built into the electric motor 8 or the reduction gear. The gear configuration is not limited to spur gears, and may be helical gears, etc. In the kneader, each kneading rotor may be connected to each gear via a coupling.

[0038] In the configuration of Fig. 2, the rotor shafts 5A and 5B are rotated by driving the electric motor 8, which rotates the kneading rotors 3A and 3B, thereby performing kneading. In Fig. 2, the closed-type kneader 1 has a configuration in which the pair of kneading rotors 3A and 3B rotate at different speeds. The number of teeth of the pair of gears 7A and 7B is not particularly limited, but a combination of different numbers of teeth that are not prime integers is more effective because it takes a shorter time to restore the same phase (see Fig. 3, for example). In Fig. 2, the kneading rotor 3A corresponds to the driving rotor, and the kneading rotor 3B corresponds to the driven rotor.

[0039] In addition, in a configuration in which a pair of kneading rotors 3A, 3B rotate at different speeds, the combination of the number of teeth is not particularly limited, but for example, it is preferable that the number of teeth of the gear with the larger number of teeth is 10% to 50% larger than the number of teeth of the other gear. In addition, if the number of teeth of the pair of gears is such that the high-speed rotor and the low-speed rotor (driven rotor) return to the same phase within 10 rotations of the high-speed rotor (drive rotor), the convergence of the variance and standard deviation can be more clearly determined by adopting that period as the time of the moving average.

[0040] Returning to Fig. 1, the control unit 12 is mainly composed of a microcomputer including a known CPU, ROM, RAM, etc. The sensors 10, 11 provided in the closed type kneader 1 for detecting kneading parameters are connected to the control unit 12. During kneading, kneading parameters such as the temperature of the material to be kneaded, the pressure of the pressurizing lid in the kneader, the effective value of the AC current supplied to the motor, the DC current value supplied to the motor, the power value consumed by the motor, the load factor of the motor, or the output torque of the motor are repeatedly sampled and acquired by the control unit 12 and stored. The control unit 12 also has various calculation functions.

[0041] For example, the temperature of the material to be kneaded is detected by a temperature sensor 10 as shown in Fig. 1, and the detection signal is acquired by the control unit 12. The pressure of the pressurizing lid 9a in the closed type kneader 1 is a pressure load due to the weight pressure of the pressurizing lid 9a that suppresses the floating of the material to be kneaded from above the kneading tank 2, and is detected by an arbitrary sensor, and the detection signal is acquired by the control unit 12.

[0042] When the motor is an AC motor, the effective value of the AC current supplied to the motor is calculated based on the detection signal of the current sensor. For example, the effective value of the AC current can be calculated by dividing the maximum instantaneous value by √2. When the motor is a DC motor, the value of the DC current supplied to the motor is detected based on the detection signal of the current sensor.

[0043] The power value consumed by the motor is detected by, for example, a power sensor 11 provided in the motor 8 as shown in Fig. 2, and the detection signal is acquired by the control unit. For example, when the motor is an AC motor, the power value consumed by the motor is active power P, which is expressed by the following formula (1). Active power P = V I cosθ (1) In the above equation (1), the effective value of the voltage applied to the motor is V, the effective value of the AC current supplied to the motor is I, the phase difference between the voltage and current is θ, and the power factor is cos θ. Furthermore, when the motor is a DC motor, the power consumed by the motor is expressed as the product of the voltage V applied to the motor and the DC current I supplied to the motor.

[0044] The load factor of the motor is expressed by the following formula (2), for example, based on the power value consumed by the above-mentioned motor and the rated value of the motor. Load factor (%) = [Power consumed by motor (W) / Rated value of motor (W)] × 100 (2)

[0045] The output torque of the motor is detected, for example, by a torque sensor provided in the motor. Alternatively, in a means that does not rely on a torque sensor, the output torque is calculated, for example, based on the power value consumed by the motor and the rotation speed or angular velocity of the motor. Well-known sensors can be used for each sensor for acquiring the above-mentioned kneading parameters.

[0046] In addition, in FIG. 1, a configuration is shown in which the temperature of the material to be kneaded and the value of the power consumed by the electric motor are acquired as the kneading parameters, but the present invention is not limited to this.

[0047] As shown in Fig. 1, the control unit 12 has an acquisition unit 13 that repeatedly samples and acquires at least one of the kneading parameters described above. In Fig. 1, the control unit 12 also has a calculation unit 14 that calculates, as an evaluation index, a moving average of a predetermined arbitrary time width, a variance of the arbitrary time width, a standard deviation of the arbitrary time width, a deviation between the input value and the moving average of the arbitrary time width, or a processed value of these, or a combination of these, for the input value acquired by the acquisition unit 13. For example, the calculation unit 14 calculates, for the input value, (A) a moving average of a predetermined arbitrary time width immediately before the current time, (B) a variance of a predetermined arbitrary time width immediately before the current time, (C) a standard deviation of a predetermined arbitrary time width immediately before the current time, (D) a deviation between the input value and the moving average of a predetermined arbitrary time width immediately before the current time, or a processed value of (A) to (D), or a combination of (A) to (D) and the processed values ​​of these.

[0048] In addition, when the kneader is configured such that a pair of tangential rotors rotate at different speeds, it is preferable that the calculation unit 14 calculates, for the input values, (A1) a moving average of the period immediately preceding the current time until the kneading rotors 3A and 3B return to the same phase, (B1) a variance of the period immediately preceding the current time until the kneading rotors 3A and 3B return to the same phase, (C1) a standard deviation of the period immediately preceding the current time until the kneading rotors 3A and 3B return to the same phase, (D1) a deviation between the input value and the moving average of the period immediately preceding the current time until the kneading rotors 3A and 3B return to the same phase, or a value obtained by processing (A1) to (D1), or a combination of (A1) to (D1) and the values ​​obtained by processing these. As shown in Fig. 7, by using the period until the kneading rotors 3A and 3B return to the same phase as the predetermined arbitrary time width, the state of each cycle from a certain phase to the return of the kneading rotors 3A and 3B to the same phase can be accurately grasped, and as a result, the change in the physical properties of the material to be kneaded can be more easily grasped. This makes it possible to accurately determine the timing to end kneading, for example.

[0049] The moving average can be calculated using a known moving average calculation method such as a simple moving average (SMA), a weighted moving average (WMA), an exponential moving average (EMA), or a centered moving average (CMA).

[0050] As an example, Fig. 3 shows a pair of gears in which the drive gear has 25 teeth and the driven gear has 30 teeth. In this case, the drive rotor connected to the drive gear rotates six times (the driven rotor rotates five times), and the drive rotor and the driven rotor return to the same phase. Fig. 3 shows a pair of rotor shafts as seen from the gear side, and shows the state in which the pair of gears are meshed. For convenience, in Fig. 3, the positions of the valleys of the driven gear with which the teeth of the drive gear mesh are indicated by circled numbers.

[0051] 1, the control unit 12 is configured to be able to evaluate a change in the kneading state based on the evaluation index calculated by the calculation unit 14. Specifically, the control unit 12 has a determination unit 15 that determines the end timing based on the evaluation index calculated by the calculation unit, and a notification unit 16 that notifies the user when it has been determined by the determination unit 15 that it is time to end the kneading.

[0052] The determination unit 15 determines the end timing based on the moving average, variance, standard deviation, and deviation calculated by the calculation unit 14. The method for this determination is not particularly limited, and the method described in FIG. 4 or the like can be used.

[0053] The notification unit 16 has a function of notifying the completion of kneading. The notification means is not particularly limited, and one or a combination of the following means may be used: displaying the completion to the operator on a monitor, notifying the operator by sound or voice, notifying the operator by communication to the outside, notifying by a lamp display, etc.

[0054] Next, an example of a processing procedure during kneading executed by the control unit is shown in Fig. 4. In the flowchart of Fig. 4, the processing from start to end is repeatedly executed at predetermined time intervals. Note that, although the above-mentioned parameters are appropriately used as the kneading parameters, the following description will be given of an example using electric power values.

[0055] First, the power value detected by the power sensor is acquired by the acquisition unit at a predetermined sampling period (for example, every 0.1 to 1 second) (step S11). The acquired power value is stored in the storage unit every time it is acquired.

[0056] In step S12, the calculation unit calculates, for example, a moving average of power values ​​for n seconds immediately preceding the current time based on the acquired power values. FIG. 5 shows an image of calculating a simple moving average (SMA) as an example of the moving average. In FIG. 5, in a configuration in which power values ​​are acquired every 0.2 seconds, for example, the calculation unit calculates a simple moving average for 5 seconds immediately preceding the current time (5-second simple moving average). Note that the simple moving average is calculated including the input value at the current time. For example, SMA1 is calculated at current time 1, SMA2 is calculated at current time 2 (1 second after current time 1), and SMA3 is calculated at current time 3 (1 second after current time 2).

[0057] In step S13, the calculation unit calculates the standard deviation SD of the power values ​​for, for example, the last n seconds from the current time based on the acquired power values. Note that the idea of ​​the last n seconds from the current time is the same as that in FIG. 5.

[0058] In step S14, the determination unit determines the timing to end the kneading. The determination of the timing to end is performed, for example, based on the calculated standard deviation SD. Specifically, it is determined whether the standard deviation SD is equal to or less than the determination threshold. If the standard deviation SD is not equal to or less than the determination threshold, it is determined that it is not the time to end (step S14: No), and the process ends. On the other hand, if the standard deviation SD is equal to or less than the determination threshold, it is determined that it is the time to end (step S14: Yes). Here, the determination threshold is a value at which the variation in power value can be considered to have converged, and is appropriately set by experiment, etc. Also, the determination threshold may be set to a different value depending on the kneading parameters used.

[0059] When it is determined in step S14 that it is time to end the kneading process, for example, the supply of driving power to the motor unit is stopped. Also, if necessary, the notification unit notifies the operator that the kneading process has ended (step S15).

[0060] In this way, the processing procedure in FIG. 4 is a combination of the moving average and the standard deviation for the same period. The method of determining the end timing is not limited to the above method. For example, the variance of the power value for the n seconds immediately preceding the current time may be used, and the variance may be compared with a judgment threshold to determine that it is the end timing if it is equal to or less than the judgment threshold. The variance is calculated as the square of the standard deviation. The moving average MA itself may also be used as a judgment index for the determination. In this case, it may be determined that it is the end timing based on the fact that the value of the input value at the current time falls within a range of 80% to 120% (preferably 90% to 110%) of the moving average for a predetermined period of time in succession.

[0061] In addition to the level of the above kneading parameters, the above judgment may be made based on the level of the moving average MA of the calculated kneading parameters, the first derivative of the moving average MA and its change, the maximum and minimum of the moving average MA, the standard deviation SD, or a combination of these.

[0062] Next, the conventional technology and the present invention will be compared with each other using the specific graphs of Figs. 6 to 8. First, Fig. 6 shows the conventional technology. Fig. 6 shows the temporal variation of various parameters when a rubber composition is mixed as a mixing material using a tangential closed type mixer having a pair of gears, the driving gear having a tooth number m of 25 and the driven gear having a tooth number n of 30. In this example, mixing is performed at a driving rotor rotation speed of 36 rpm and a driven rotor rotation speed of 30 rpm, and the driving rotor and the driven rotor return to the same phase every 10 seconds. Here, the temperature in the figure indicates the temperature of the mixing material detected by the temperature sensor (continuous value), the power indicates the power value consumed by the electric motor detected by the power sensor (specifically, the active power of the AC electric motor), and the torque indicates the torque of the electric motor detected by the torque sensor (continuous value).

[0063] In Figure 6, the kneading parameters are monitored by the conventional method, and it can be seen that the values ​​of each kneading parameter fluctuate in a discrete zigzag manner. In particular, the power fluctuates greatly in a zigzag manner. With such a graph, it is relatively difficult to grasp the time-dependent changes in the state of the kneaded material.

[0064] In contrast, Fig. 7 and Fig. 8 show graphs to which the method of the present invention is applied. Specifically, in addition to the time fluctuation of the original kneading parameters, the graphs show the calculated simple moving average (SMA) of the power value in a predetermined time width and the standard deviation (2σ, -2σ) of the power value in the same time width. Note that Fig. 7 and Fig. 8 show different settings of the time width for calculating the simple moving average SMA, etc. That is, in Fig. 7, the time width for which the simple moving average SMA and standard deviation are calculated is set to 10 seconds, and in Fig. 8, it is set to 17 seconds. In Fig. 7, the time width for which the calculation is performed is the period until the pair of rotors return to the same phase. On the other hand, in Fig. 8, the time width is set arbitrarily.

[0065] In Fig. 7, the simple moving average of the power value W SMA is calculated as a simple moving average of the last 10 seconds from the current time. If the number of samples for the last 10 seconds is n, it is calculated using the following formula (3).

[0066] In addition, the standard deviation W of the power values ​​sampled n times in the last 10 seconds is SD was calculated using the following formula (4).

[0067]

number

[0068] As shown in Figure 7, the standard deviation (power (SD; 2δ), power (SD; -2δ)) can be plotted on the positive and negative sides with the 10-second simple moving average of power (power (SMA)) at the center. From Figure 7, it can be seen that the bandwidth of the standard deviation on the positive and negative sides converges significantly around the time period just before "15:08". This means that the variation in the power consumed by the motor converges significantly from this time period, and indicates that the state of the entire mixed material has, for example, progressed in mixing and dispersion as the kneading progresses, and the entire mixed material has become homogenous. The point in time of this state change can be used as a direct indicator for determining the end of kneading, or it can be used as an indicator for indirectly determining the end timing, such as when a certain amount of time has passed after this state change or when a certain amount of energy has been input. Therefore, by determining when the standard deviation is equal to or less than the judgment threshold, it is possible to determine the convergence of the bandwidth as shown in Figure 7, which in turn leads to determining the end timing. In Figure 7, the fluctuating power value is smoothed by the simple moving average, and the variation (standard deviation) is further visualized.

[0069] In addition, in Fig. 8, the time span for calculating the simple moving average SMA and standard deviation is set to 17 seconds. As shown in Fig. 8, the standard deviation bandwidth converges toward the end of the kneading process, and even in this case, the end timing can be determined by comparing the standard deviation with a judgment threshold. Note that the behavior of the standard deviation converges more slowly than in Fig. 7.

[0070] From the results of Figures 7 and 8, it can be said that it is easier to grasp the state change by setting the time period until the pair of rotors return to the same phase as the time width for calculating the moving average, standard deviation, etc. By using the characteristic cycle in such a configuration in which the rotors rotate at different speeds in the calculation process, it becomes easier to grasp the change in the physical properties of the kneaded material, and ultimately the end timing can be accurately determined.

[0071] On the other hand, in the conventional method, for example, the end temperature of kneading is set to a predetermined temperature (for example, 120°C), and kneading is ended when the temperature of the material to be kneaded reaches that temperature. Since the temperature of the material to be kneaded varies depending on the heat capacity of the raw materials, the amount of energy input, and the amount of energy lost by heat removal and heat dissipation, the end judgment based on the temperature level can be said to be a judgment criterion based on the integral of the amount of energy input from the start of kneading. In contrast, the above method according to the present invention provides a means for grasping the change in the physical properties of the material to be kneaded during kneading by acquiring kneading parameters such as the electric power value of the electric motor in real time and using the moving average and the standard deviation for the same period to judge the tendency of change in the kneading parameters, the convergence of the variation, etc., and thereby enabling the kneading to be ended quickly and at an appropriate timing, and enabling efficient kneading processing.

[0072] 7 and 8 show the results using the power value consumed by the motor as the kneading parameter, but other kneading parameters can also be used to grasp the changes in the physical properties of the kneaded material. For example, the effective value of the AC current supplied to the motor, the DC current value supplied to the motor, the load factor of the motor, and the output torque of the motor are parameters closely related to the power value consumed by the motor, and similar results can be obtained.

[0073] Although the simple moving average is used as the smoothing process in the above, a moving average calculated by another moving average method may be used. The results of each process are shown below using a power chart.

[0074] First, the power chart in Fig. 9(a) shows a simple moving average (SMA), while the other Figs. 9(b) to (d) show a comparison with the simple moving average. In each power chart shown in Fig. 9, the horizontal axis represents the rotation speed of the drive rotor. In this case, the drive rotor rotates six times (the driven rotor rotates five times) until the drive rotor and the driven rotor return to the same phase. The time span for calculating the moving average is the period until the pair of rotors return to the same phase, and the moving average is calculated over the time it takes for the drive rotor to rotate six times.

[0075] The weighted moving average (WMA) in Figure 9(b) is a method of linear weighting, which gradually reduces the weight from the present to the past in a linear manner to make it easier to respond to fluctuations. As shown in Figure 9(b), the WMA has better tracking ability for raw time series data than the SMA. The WMA is calculated using the following formulas (5) and (6).

number

[0076] The exponential moving average (EMA) in Figure 9(c) is a method of applying weights that decrease exponentially. As shown in Figure 9(c), the EMA has better tracking ability for raw time series data than the SMA. However, the amplitude is relatively large. For example, the exponential moving average S at time t t is calculated using the following formula (7). The initial value is calculated using the simple moving average of the previous raw time series data, and the EMA is calculated recursively.

number

[0077] The Centered Moving Average (CMA) in Figure 9(d) is a method for taking the average of N / 2 data points in the past and N / 2 data points in the future. As shown in Figure 9(d), the CMA has better tracking ability for raw time series data than the SMA.

[0078] Figure 10 shows an example of smoothing processing using a low-pass filter. For example, a discrete Fourier transform is performed to remove high-frequency components (see Figure 10(a)). As shown in Figure 10(b), the tracking is good in the middle of the kneading process, but fitting is not possible immediately after the start or end of the kneading process.

[0079] Figure 11 shows an overlaid chart of each smoothing process. As shown in Figure 11, the smoothing process method has different levels of tracking to fluctuations, with EMA, WMA, and SMA (CMA) showing the strongest tracking in this order. Table 1 shows the results of evaluating these methods using mean squared error.

[0080] [Table 1]

[0081] As shown in Table 1, although the EMA still has some vibrations, it has good tracking and fitting to the raw time series data. In addition, the CMA is considered to be suitable for predicting the final torque (power), final temperature, and amplitude after removing the vibrations.

[0082] Next, another form of evaluation method using moving average MA will be described. As a conventional method for judging a change in the kneading state, for example, a method of visually evaluating the tendency of change in a power chart is known. For example, the time from when a compounding agent such as carbon black is added until it is integrated is widely recognized and emphasized in the rubber field as Black Incorporation Time (BIT). However, as shown in FIG. 12(a), an actual power curve is a discrete zigzag broken line, and which point in the range indicated by the cloud in the figure is the peak (maximum or minimum) depends on the subjective judgment of the person. Therefore, when attempting to evaluate an actual power curve using conventional technology, the position of the peak and the tendency of change are not necessarily clearly grasped because the power value changes greatly in a short time.

[0083] The new evaluation method of the present invention can solve the above problems. Figure 12(b) shows an example of the application of the present invention, in which a moving average MA is used to identify a local maximum.

[0084] The specific steps are shown below. (1) As described above, calculate the moving average MA for any recent time span. (2) Trends are identified using the first derivative of the moving average MA, the slope of the moving average MA, or the distribution of the blending parameters relative to the moving average MA. (3) The local maximum and minimum are identified by comparing the first and second derivatives of the moving average MA, or the values ​​of consecutive moving average MA. For example, the point where the first derivative of the moving average MA changes from positive to negative, or the point where the first derivative is 0 and the second derivative is negative, can be identified as the local maximum of the original kneading parameters. Also, the point where the first derivative of the moving average MA changes from negative to positive, or the point where the first derivative is 0 and the second derivative is positive, can be identified as the local minimum. The means for identifying the local maximum and minimum using the moving average MA may be a method using a higher order derivative than the first or second derivative, or a means for identifying from the distribution and comparison of the current and previous values.

[0085] Furthermore, (4) the variance and standard deviation (SD) may be calculated from the distribution of the mixing parameters for the target period for which the moving average MA was calculated, and the changes may be observed. In Fig. 12(b), the moving average MA and standard deviation SD are displayed and visualized together with the mixing parameters.

[0086] Figure 13 shows a specific method for obtaining BIT and Black Wetting Time (BWT) as extreme values. BIT is the point at which the torque reaches its maximum value when the carbon is inserted into the rubber and the rubber adheres to each other to form a large rubber mass and become integrated, and BWT is the point at which the torque reaches its minimum value when the finely divided polymer is covered with carbon black and becomes slippery. Figure 13(a) shows a method for obtaining extreme values ​​by differentiating a function obtained by applying a low-pass filter to the EMA. After taking the EMA, applying a low-pass filter can improve smoothing (see Table 1). In addition, the low-pass filter is obtained as a differentiable function, so it is suitable for the method of obtaining extreme values ​​by differentiation. Figure 13(b) shows a method for obtaining extreme values ​​by applying the SciPy find_peaks function to the CMA. For example, when obtaining a maximum value, find_peaks sets a point higher than both neighboring points as the maximum value.

[0087] As shown in Figures 12 and 13, smoothing using the moving average MA and further combining it with other processes can identify local maximums and minimums. Identifying the local maximum can also help understand the BIT, and identifying the local minimum can also help understand the BWT. It is also possible to evaluate the time elapsed from the start of kneading to reaching the local maximum, and the time elapsed from reaching the local maximum to the convergence of the standard deviation SD.

[0088] As another form of evaluation method using moving average MA, it is also possible to grasp the point (inflection point) where the slope of the kneading parameter changes at the end of the kneading process. After the inflection point, the rubber becomes soft due to the influence of temperature, and further kneading cannot be effective. Therefore, by grasping the inflection point, it is possible to determine the end of rubber kneading. For example, the inflection point can be obtained by second-order differentiation of a function obtained by applying a low-pass filter to EMA. For example, in FIG. 14, it can be determined that a specific inflection point indicates the end point among the circles shown on the graph.

[0089] FIG. 14 shows 12 inflection points. There are always an odd number of inflection points between the extreme values ​​(maximum and minimum) shown in FIG. 13(a), including one case, and the odd-numbered inflection point after the third maximum value in FIG. 13(a) is a candidate for the end point. The point after which the maximum value is to be focused on is arbitrarily set according to the blend to be kneaded and the kneading pattern. For this judgment, a threshold value is set to judge the vicinity of 0 (zero) for the value obtained by second-order differentiation, and when the value obtained by second-order differentiation after the odd-numbered inflection point after the maximum value exceeds the positive threshold value near 0 (zero), it can be judged that the inflection point immediately before that indicates the end point. For example, in FIG. 14, it can be judged that the inflection point shown around 100 rotations on the horizontal axis indicates the end point.

[0090] From the time the material is added until the completion of mixing, it passes through the stages of "pulverization and adhesion," "integration," and "mixing and homogenization," and finally a homogenized mixed material is obtained. As mentioned above, for example, by smoothing using the moving average MA, it is possible to grasp the maximum and minimum, inflection points, etc., and the state of each stage can be accurately grasped. As a result, it is believed that stable mixing can be performed even with different batches and conditions.

[0091] In this specification, population variance and population standard deviation are given as examples of application of the technology, but the present invention is not limited to these, and sample variance, sample standard deviation, sample unbiased variance, and sample unbiased standard deviation may also be used.

[0092] According to the present invention described above, for example, the following effects can be obtained. · The trend of the kneading parameters can be clearly seen based on the slope of the moving average MA. -The maximum and minimum values ​​of mixing parameters can be clearly detected. No influence from human subjectivity. The distribution of the mixing parameters relative to the moving average MA is expressed as the standard deviation SD, and the magnitude of the fluctuation range can be captured. Changes in the mixing state can be detected from the convergence point and convergence trend of the standard deviation SD. The bias in the distribution of the mixing parameters relative to the moving average MA makes it possible to predict the future trend of changes in the mixing parameters. For example, in Figure 12(b), it can be seen that after the convergence point (see Figure 7), the plotted power points are concentrated below the moving average MA, and are hardly distributed above the moving average MA. Therefore, by understanding the bias in the distribution relative to such a moving average, it is possible to predict the trend of the moving average change, that is, the moving average MA will continue to decline to the right.

[0093] Trends can also be determined by using short-term and long-term moving averages. Each moving average can be calculated by the method described above. For example, the long-term moving average is calculated for an interval that is an integer multiple (e.g., 2 to 5 times) of the interval for calculating the short-term moving average. If the short-term moving average is larger than the long-term moving average, it can be determined that the trend is rising, and if the long-term moving average is larger than the short-term moving average, it can be determined that the trend is falling.

[0094] The specific configuration of the evaluation method and kneading machine of the present invention is not limited to the configuration shown in the above figures, and can be modified as appropriate.

[0095] In the examples shown in the above figures, the rotational speed of the drive rotor is constant, but the present invention can be applied even when the rotational speed of the drive rotor (=r) changes (e.g., r1→r2) during the process. In this case, the time required for the drive rotor to make one rotation also changes with the change in the rotational speed. Therefore, even after the rotational speed changes, the moving average can be calculated over the period in which the drive rotor rotates the same number of times, by changing the time width to be calculated according to the period after the change. For example, while the moving average was calculated over 10 seconds (the period in which the drive rotor rotates six times) before the change in the rotational speed, the moving average can be calculated over 15 seconds (the period in which the drive rotor rotates six times) after the rotational speed is reduced to two-thirds, so that the time width to be calculated can be changed. This makes it easier to continuously grasp the kneading state well even when the rotational speed of the pair of rotors changes during the process.

[0096] In addition, in response to changes in the rotation speed, the time series data with the sampling time as an index can be converted into rotation speed series data or rotation angle series data with the rotation speed, rotation angle, or angular distance as an index, and used. The time series data obtained by sampling includes the sampling time and the rotor rotation speed (r / min) or angular velocity (rad / s or ° / s), so that the sampling time t n and sampling time tn+1 By integrating this displacement angle, the number of rotations (r or rotations) or the rotation angle or angular distance (rad or °) at each sampling time that the rotor has rotated from the initial state can be calculated to derive new data that can be added to the time series data.

[0097] From this derived time series data, it is possible to use rotation number series data or rotation angle series data in which the rotation number, rotation angle, or angular distance is used as an index instead of the sampling time. Here, the series that serves as an index will be called an index series.

[0098] For example, by using rotation speed series data with the rotation speed as an index, it is possible to obtain the moving average and standard deviation of the values ​​of a series other than the index series during any rotation speed, such as six rotations of the drive rotor. In this way, by deriving rotation speed series data or rotation angle series data with the rotation speed, rotation angle, or angular distance as an index from time series data, it is possible to obtain the same effect as changing the time span for calculating the moving average from the change in the rotation speed.

[0099] In both time series data and rotation speed series data or rotation angle series data with the rotation speed or rotation angle as indexes, the original data can be resampled and used so that the index series values ​​are at any fixed interval. For example, in the case of rotation speed series data where the index is the rotation speed, resampling can be done at fixed intervals of 1 / 6 rotation. In this case, for series other than the index series, values ​​corresponding to the index series can be obtained from the original rotation speed series data by linear interpolation or first-order spline interpolation, second-order spline interpolation or third-order spline interpolation, and new rotation speed series data can be derived.

[0100] The resampling of the index sequence values ​​to regular intervals is performed before performing a discrete Fourier transform to evaluate the periodic variation of any data sequence or the spectrum of the signal, or before applying a low-pass filter.

[0101] FIG. 13(a) shows an example in which, after conversion to rotation speed series data, an exponential moving average (EMA) is calculated, and the rotation speed values, which are the index series, are resampled at regular intervals, after which a low-pass filter is applied, with the horizontal axis representing the rotation speed.

[0102] Although the above describes a method for evaluating kneading in real time, the present invention may also be used to analyze and evaluate accumulated data later. As a method for analyzing later, a method of calculating a moving average MA and a standard deviation SD based on collected and recorded kneading parameters, and visualizing and displaying the convergence timing by superimposing the kneading parameters, the moving average MA, and the standard deviation SD on a graph (see Figs. 7 and 8), or a method of displaying two different batches in the same way and comparing them, can be adopted.

[0103] The calculation of the moving average MA and standard deviation SD, conversion to rotation speed series data or rotation angle series data, resampling, application of a low-pass filter, and other conversion or derivation of data series and processing based on data series are performed by a conversion routine that inputs one or more data series and conversion parameters and outputs one or more derived data series.

[0104] In addition, multiple conversion routines are chained together in a predefined order depending on the purpose, and executed to obtain the desired data sequence. This chain of multiple predefined conversion routines is called a pipeline. In the example of FIG. 13(a), the pipeline is configured as follows: The rotation speed series (unit: r) from the initial state is derived from the sampling time series and rotation speed (r / min) series of the original time series data. Using the rotation speed series as an index, an exponential moving average (EMA) is calculated over six rotations of the power series to derive the power EMA series. The rotation speed series and EMA series are input and smoothed into a curve by applying a low-pass filter. The smooth curve function is used as input to find the extreme values ​​(Figure 13(a)). The function of the smoothed curve is used as input to find the inflection point (Figure 14).

[0105] Multiple conversion routines are applied in one pipeline, but by using multiple pipelines in combination, it is possible to grasp the kneading state and changes in physical properties. In the pipeline applied to Fig. 12(b), it can be seen that the standard deviation of the power values ​​converges after 15:08. In the same period, the step can be determined to be completed when the function of the smoothed curve of the power value EMA passes the maximum value and the first derivative remains negative as in the example of Figure 13(a) described above, and when the second derivative of the processed function passes the last maximum value and after the odd-numbered inflection point exceeds a positive threshold near 0 and changes sign as in the example of Figure 14. [Industrial Applicability]

[0106] The kneading state evaluation method and kneading machine of the present invention can grasp the change in the physical properties of the material to be kneaded using various kneading parameters in a closed kneading machine with a pair of rotors, and can be widely used in the kneading of rubber, plastics, ceramics, etc. This is expected to contribute to improving productivity and stabilizing quality, such as shortening the kneading time by grasping the end point of kneading with higher accuracy. [Explanation of symbols]

[0107] 1. Closed mixer 2. Mixing tank 2A, 2B rotor chamber 2C Mausoleum wall section 3A, 3B kneading rotor 4a, 4b blades 5A, 5B Rotor shaft 6A, 6B bearings 7A, 7B Gear 7a Mounting hole 7b Key groove 8 Electric motor 8a Circuit section 8b Motor section 9a Pressure lid 9b Rod 10 Temperature Sensor 10a Detection end 11 Power Sensor 12 Control section 13 Acquisition Department 14 Calculation section 15 Judgment section 16. Notification Department 17 Coupling

Claims

1. A method for evaluating a kneading state in a kneader having a pair of rotors connected by a pair of gears and rotated by driving an electric motor, comprising: The evaluation method for evaluating a kneaded state is characterized in that the temperature of the material to be kneaded, the pressure of the pressure lid of the kneader, the effective value of the AC current supplied to the motor, the DC current value supplied to the motor, the power value consumed by the motor, the load factor of the motor, the output torque of the motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor are repeatedly sampled and acquired, and a moving average of a predetermined arbitrary time width, a variance of an arbitrary time width, a standard deviation of an arbitrary time width, a deviation between the input value and the moving average of an arbitrary time width, or processed values ​​of these, or a combination of these, of the acquired input values ​​are used as evaluation indexes.

2. In the kneader, the pair of rotors are tangential rotors, the gears have different integer numbers of teeth, and the pair of tangential rotors rotate at different speeds, The method for evaluating the kneading state described in claim 1, characterized in that the evaluation method uses, as the arbitrary time width, the period immediately preceding the current time of the input value until the pair of rotors return to the same phase, and uses, as the evaluation index, a moving average of the period, a variance of the period, a standard deviation of the period, a deviation between the input value and the moving average of the period, or a combination of these.

3. A method for evaluating the kneaded state according to claim 1 or claim 2, characterized in that, when the rotation speed of the pair of rotors in the kneader changes during the process, the arbitrary time width is changed in accordance with the change in the rotation speed, and a moving average of the changed time width, a variance of the changed time width, a standard deviation of the changed time width, a deviation between the input value and the moving average of the changed time width, or a combination of these is calculated.

4. A method for evaluating a kneading state in a kneader having a pair of rotors connected by a pair of gears and rotated by driving an electric motor, comprising: The evaluation method for evaluating a kneaded state is characterized in that the temperature of the material to be kneaded, the pressure of the pressure lid of the kneader, the effective value of the AC current supplied to the motor, the DC current value supplied to the motor, the power value consumed by the motor, the load factor of the motor, the output torque of the motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor are repeatedly sampled and acquired, and a moving average of the acquired input values ​​for a predetermined arbitrary number of rotations of one of the rotors, a variance for an arbitrary number of rotations, a standard deviation for an arbitrary number of rotations, a deviation between the input value and the moving average for an arbitrary number of rotations, or processed values ​​of these, or a combination of these, is used as an evaluation index.

5. 5. The method for evaluating a kneaded state according to claim 1, wherein the end timing is determined based on whether the variance, the standard deviation, or the deviation is equal to or smaller than a determination threshold value.

6. 5. The method for evaluating a kneaded state according to claim 1, wherein the kneader is a kneader for kneading a non-Newtonian fluid.

7. The method for evaluating the kneading state according to claim 1 or claim 4, characterized in that a combination of a moving average of the period and a standard deviation of the period is used as an evaluation index, and the end timing is determined based on the standard deviation being equal to or less than a judgment threshold value.

8. A kneader including a pair of rotors connected by a pair of gears and rotated by driving an electric motor, The kneader is characterized in having an acquisition unit that repeatedly samples and acquires the temperature of the material to be kneaded, the pressure of a pressure lid in the kneader, the effective value of the AC current supplied to the motor, the DC current value supplied to the motor, the power value consumed by the motor, the load factor of the motor, the output torque of the motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor, and a calculation unit that calculates a moving average of a predetermined arbitrary time width, a variance of an arbitrary time width, a standard deviation of an arbitrary time width, a deviation between the input value and the moving average of an arbitrary time width, or a value obtained by processing these, or a combination of these, of the input values ​​acquired by the acquisition unit.

9. In the kneader, the pair of rotors are tangential rotors, the gears have different integer numbers of teeth, and the pair of tangential rotors rotate at different speeds, The kneader according to claim 8, characterized in that the calculation unit uses, as the arbitrary time width, a period immediately preceding a current time of the input value until the pair of rotors return to the same phase, and calculates a moving average of the period, a variance of the period, a standard deviation of the period, a deviation between the input value and the moving average of the period, or a combination of these.

10. The kneader according to claim 8 or claim 9, characterized in that, in the case where the rotation speed of the pair of rotors in the kneader changes during the process, the calculation unit changes the arbitrary time width in accordance with the change in the rotation speed, and calculates a moving average of the changed time width, a variance of the changed time width, a standard deviation of the changed time width, a deviation between the input value and the moving average of the changed time width, or a combination of these.

11. A kneader including a pair of rotors connected by a pair of gears and rotated by driving an electric motor, The kneader is characterized in having an acquisition unit that repeatedly samples and acquires the temperature of the material to be kneaded, the pressure of a pressure lid in the kneader, the effective value of the AC current supplied to the electric motor, the DC current value supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, the output torque of the electric motor, the number of rotations per minute of the rotor, or the angular velocity of the rotor, and a calculation unit that calculates a moving average of the input values ​​acquired by the acquisition unit for a predetermined arbitrary number of rotations of one of the rotors, a variance for the arbitrary number of rotations, a standard deviation for the arbitrary number of rotations, a deviation between the input value and the moving average for the arbitrary number of rotations, or values ​​obtained by processing these, or a combination of these.

12. 12. The kneader according to claim 8, further comprising a determination unit that determines a termination timing based on whether the variance, the standard deviation, or the deviation calculated by the calculation unit is equal to or smaller than a determination threshold value.

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