JP7299655B1 - Evaluation method of kneading state and kneading machine - Google Patents

Abstract

A kneading state evaluation method and a kneader capable of grasping changes in physical properties of a kneaded material in a closed-type kneader with a tangential rotor are provided. A kneading state evaluation method is an evaluation method in a closed type kneader 1 provided with a pair of tangential rotors connected by a pair of gears and rotated at different speeds by being driven by an electric motor. The sensors 10 and 11 provided in the internal kneader 1 have non-prime and different integer numbers of teeth, and spectrum analysis is performed based on the kneading parameters detected during kneading. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a method for evaluating a kneading state when a kneading material such as rubber, plastic, ceramics, etc. is kneaded by a kneader, and to a kneader.

Conventionally, a closed type kneader is known as an apparatus for kneading various kneading materials (see Patent Document 1, for example). In this closed type kneader, after the kneading material is put into the kneading tank, the kneading material is kneaded by rotating the two kneading rotors. In general, as kneading rotors for closed-type kneaders, there are known a meshing rotor that rotates so that two kneading rotors mesh with each other, and a tangential (non-meshing) rotor.

Here, FIG. 10 shows an example of a closed kneader equipped with a tangential rotor. FIG. 10 is a schematic plan view of the kneader. In FIG. 10, a closed type kneader 21 includes a kneading tank 22, two kneading rotors 23A and 23B arranged side by side in the kneading tank 22, and rotor shafts 25A and 25B of the kneading rotors 23A and 23B which are rotatable. bearings 26A, 26B and a pair of gears 27A, 27B. Spiral blades 24a and 24b are formed on the outer circumferences of the kneading rotors 23A and 23B, respectively.

In FIG. 10, of rotor shafts 25A and 25B, one rotor shaft (for example 25A) is connected to a driving means such as a motor, and the other rotor shaft (for example 25B) is connected to one rotor shaft. They are connected via a pair of gears 27A and 27B. By rotating the rotor shaft 25A with the driving means, the kneading rotors 23A and 23B are rotated to knead the kneaded material. 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.

In a closed kneader with a tangential rotor as shown in FIG. 10, a speed difference of about 15% to 25% is generally provided between the driving rotor and the driven rotor by varying the gear ratio of the pair of gears. often. By rotating these kneading rotors at different speeds, the phases of the driving rotor and the driven rotor are changed, and even kneading is performed.

JP-A-9-313916 WO2021/033390

Conventionally, in closed-type kneaders with tangential rotors, the end of kneading is determined using (1) kneading time, (2) temperature of kneaded material, (3) power consumption, and a combination thereof. . For example, the temperature of the material to be kneaded rises as the kneading progresses. When the temperature of the kneaded material is used as an index, for example, when the temperature reaches a predetermined temperature, it is determined that the kneading is finished. However, the conventionally used index mainly indicates the amount of energy input during kneading, and it is difficult to grasp changes in the physical properties of the kneaded material during kneading.

By the way, in recent years, as a determination system for determining the state of an object to be stirred, a waveform related to the current supplied to the drive device of a stirrer having a mechanism portion for stirring the object to be stirred and a drive device for driving the mechanism portion and a determination unit that determines the state of the object to be stirred based on changes resulting from the component of the force applied to the driving device in a specific direction, which is obtained from the waveform data. has been proposed (see Patent Document 2). In Patent Document 2, the current supplied to the driving device is an alternating current having a reference frequency, and the technology uses waveform data of the alternating current, that is, the instantaneous value of the alternating current. Specifically, an instantaneous value waveform of an alternating current, which is a sine wave, is input, and the state of the object to be stirred is determined by paying attention to the output reference frequency component and other components. Thus, there is a demand for a new technique for grasping changes in physical properties of kneaded materials during kneading.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a kneading state evaluation method and a kneader capable of grasping changes in physical properties of kneaded materials in a tangential rotor closed kneader. for the purpose.

The method for evaluating the kneading state of the present invention is a method for evaluating the kneading state in a kneader provided with a pair of tangential rotors connected by a pair of gears and rotated at different speeds by being driven by an electric motor, wherein the gears are mutually connected. It has a different integer number of teeth that is not prime, and the evaluation method is to analyze the spectrum based on the kneading parameter detected during kneading by the sensor provided in the kneader, and evaluate the change in the predetermined frequency component. wherein the kneading parameters are the temperature of the kneaded material, the effective value of the alternating current supplied to the electric motor, the value of direct current supplied to the electric motor, the power value consumed by the electric motor, and the load factor of the electric motor. , output torque of the electric motor, sound generated from the kneader, and vibration generated from the kneader. The above-mentioned evaluation method includes a mode of analyzing and evaluating the accumulated kneading parameters later, and a mode of monitoring the kneading parameters in real time.

A rotor connected to a pair of gears having m and n (m<n) teeth, having a greatest common divisor k greater than 1 between m and n, and having m teeth. When the number of revolutions is r (unit: min ⁻¹ ), spectrum analysis is performed based on the above kneading parameters, and f = (r · k) / 60n (unit: Hz) and its integer multiple or integer fraction It is characterized by evaluating changes in frequency components.

The evaluation method is a method of processing and spectrally analyzing the kneading parameter, and the method is characterized by spectrally analyzing the deviation between the moving average value and the current value of the kneading parameter.

The kneader is characterized by kneading a non-Newtonian fluid. Non-Newtonian fluids specifically include rubbers, plastics, ceramics, silicones, chewing gum compositions, and the like.

The kneader of the present invention is a kneader comprising a pair of tangential rotors connected by a pair of gears and rotated at different speeds by being driven by an electric motor, wherein the gears have different integer numbers of teeth that are not relatively prime. The kneader has an analysis unit that performs spectral analysis based on kneading parameters detected during kneading by a sensor provided in the kneader, and the kneading parameters are the temperature of the kneaded material, the electric motor RMS value of alternating current supplied to, DC current value supplied to the electric motor, power value consumed by the electric motor, load factor of the electric motor, output torque of the electric motor, sound generated from the kneader, and the It is characterized by being at least one selected from vibrations generated from a kneader.

The kneading machine is characterized by comprising a judgment section for judging the end timing of kneading of the kneading machine based on a change in the predetermined frequency component obtained by the analysis section.

The kneading state evaluation method of the present invention is an evaluation method for a kneader provided with a pair of gears having non-prime integer numbers of teeth. By setting the number of teeth of the pair of gears to different integers that are not relatively prime, the frequency of the pair of rotors being in the same phase increases, and in this configuration, the kneading parameters (e.g., the temperature of the kneaded material, the effective value of alternating current supplied to the motor, value of direct current supplied to the motor, value of power consumed by the motor, load factor of the motor, output torque of the motor, sound generated by the kneader, vibration generated by the kneader, etc.) By spectral analysis, it is possible to satisfactorily detect a spectrum characteristic of a predetermined frequency component, and by evaluating changes in the spectrum, it is possible to grasp changes in the physical properties of the kneaded material.

In addition, since the above evaluation method evaluates changes in frequency components of f = (r · k) / 60n (unit: Hz) and its integral multiples or integral fractions, it is easier to grasp changes in the physical properties of the kneaded material. Become.

It is an explanatory view showing a schematic structure of the whole kneading machine concerning the present invention. FIG. 2 is a diagram for explaining driving of a kneading rotor of the kneader of FIG. 1; It is a figure which shows an example of the number of teeth of a pair of gear. It is a graph which shows the temporal change of each parameter in a test example. It is a figure which shows the result of having carried out FFT of the electric power value in FIG. FIG. 5 is a diagram showing the result of FFT after processing the power values in FIG. 4; It is a figure which shows the result of having carried out FFT of the temperature in FIG. FIG. 5 is a diagram showing the result of FFT after processing the temperature in FIG. 4; 4 is a flowchart for explaining processing executed by a control unit; FIG. 5 is a diagram for explaining driving of a kneading rotor of a conventional kneader;

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

As shown in FIG. 1, the closed kneader 1 mainly includes a kneading mechanism including a kneading tank 2 and an electric motor 8 (see FIG. 2), and a pressurizing lid 9a for pressurizing the kneaded material put into the kneading tank. and a control unit 12 for controlling kneading of the kneading material. The evaluation method and the kneading machine of the present invention are characterized in particular by spectral analysis of predetermined kneading parameters. That is, by spectrally analyzing a predetermined kneading parameter that does not appear to be periodic at first glance, periodicity is discovered, and predetermined frequency components (for example, frequency components of the mechanical rotation period of the rotor and the synchronous period) are observed. , is used to grasp changes in physical properties of kneaded materials.

The kneading tank 2 has an inner peripheral surface shape in which two substantially C-shaped partial peripheral surfaces are connected facing each other, and two rotor chambers 2A and 2B which are adjacent to each other and communicate with each other are provided inside. be. At the inner bottom portion of the kneading tank 2, at the boundary between the inner peripheral surfaces of the two rotor chambers 2A and 2B, there is formed a mountain-shaped rising wall portion 2C. Both ends of the rotor chambers 2A and 2B in the axial direction are closed by tank end walls (not shown). The cross-sectional shape of the rotor chambers 2A, 2B is constant in the axial direction.

The closed kneader 1 has a temperature sensor 10 for detecting the temperature in the kneading tank during kneading. The temperature sensor 10 is arranged so that the detection end 10a protrudes from the upper surface of the rib portion 2C, and is capable of detecting the temperature of the kneaded material in contact with the detection end 10a. A well-known temperature sensor is used for the temperature sensor 10, and for example, a thermocouple temperature detector that measures the temperature by housing a thermocouple element in a protective tube is used. As this thermocouple temperature detector, for example, the tip of the thermocouple element is welded to the tip of the protection tube, and the temperature of the kneaded material is sensed on the outer surface of the protection tube. A non-grounded type that senses the temperature of the protective tube by contacting the inner wall of the tip can be used.

The temperature sensor provided in the closed kneader 1 is not limited to the sensor configuration and arrangement shown in FIG. 1 as long as it detects the temperature of the kneaded material during kneading. The temperature change of the kneaded material detected by the temperature sensor will be described later.

As shown in FIG. 1, in the rotor chambers 2A and 2B, kneading rotors 3A and 3B for kneading the kneaded material are rotatably arranged with a gap from the inner peripheral surfaces of the rotor chambers 2A and 2B, respectively. is set. The kneading rotors 3A, 3B each have two blades 4a, 4b. The blades 4a and 4b have a mountain-shaped cross-sectional shape from the starting end side to the terminal end side, and have a land portion at the top. This land rotates while maintaining a predetermined distance from the inner peripheral surface. The rotation of the kneading rotors 3A, 3B changes the shape of the kneading space in the rotor chambers 2A, 2B. The kneading rotors 3A and 3B rotate in opposite directions, and are configured such that the blades rotate downward on the side where both rotor chambers 2A and 2B communicate with each other.

Further, an opening is provided above the kneading tank 2 for charging the kneading material. The pressurizing lid 9a can be vertically moved 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. Thereafter, the pressurizing lid 9a is lowered by the rod 9b, and the two kneading rotors 3A and 3B are rotated while pressurizing the kneaded material. In this case, the helical blades 4a and 4b knead the kneaded material by flowing in complicated directions including not only the rotation direction of the rotor but also the axial direction.

The kneader according to the present invention is not limited to the configuration shown in FIG. The closed type kneader 1 in FIG. 1 is of a type in which the kneading tank 2 is inverted after kneading and the kneaded material is taken out from the opening. can be in the form

FIG. 2 shows a schematic plan view of a closed kneader. As shown in FIG. 2, the closed kneader 1 includes the kneading tank 2 described above, kneading rotors 3A and 3B, bearings 6A and 6B that rotatably support the rotor shafts 5A and 5B, a pair of gears 7A, 7B. Spiral blades 4a and 4b are formed on the outer circumferences of the kneading rotors 3A and 3B. For example, in the kneading rotor 3A, the blades 4a and 4b have starting ends at positions where the phases in the circumferential direction are different from each other by 180° on both ends in the axial direction of the kneading rotor 3A. The outer peripheral surface is extended in the spiral direction. The configuration of the blades in the kneading rotor is not limited to this. In FIG. 2, the lengths of the blades 4a and 4b in the spiral direction are different from each other, the blade 4a being a long blade and the blade 4b being a short blade. Note that the number of blades is not limited to two, and may be three, four, six, or the like. In that case, for example, the position of the starting end between the blades (the phase in the circumferential direction) is appropriately set according to the number of blades.

In the closed 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 an output shaft 5A' of the electric motor 8 via a coupling 16. As shown in FIG. Alternatively, the coupling 16 may be omitted and the rotor shafts 5A and 5A' may be constructed integrally. 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 portion 8a and a motor portion 8b. The circuit section 8a generates power based on the control signal and supplies the generated power to the motor section 8b. The electric motor 8 has a power sensor 11 that detects the power supplied to the motor portion 8b. In the present invention, the motor may be an AC motor driven by an AC power source or a DC motor driven by a DC power source.

In addition, the electric motor 8 may be provided with a speed reducer, and the rotational force generated from the drive source may be reduced and output. Also, the pair of gears 7A and 7B is not limited to gears provided outside the electric motor 8 as shown in FIG. The configuration of the gear is not limited to spur gears, and may be helical gears or the like. Further, in the kneader, each kneading rotor may be connected to each gear through a coupling.

In the configuration of FIG. 2, driving the electric motor 8 rotates the rotor shafts 5A and 5B, thereby rotating the kneading rotors 3A and 3B to perform kneading. In the closed-type kneader 1 according to the present invention, the pair of gears 7A and 7B have a combination of different integer numbers of teeth that are not relatively prime, and the pair of kneading rotors 3A and 3B are configured to rotate at different speeds. ing. In FIG. 2, the kneading rotor 3A corresponds to the driving rotor, and the kneading rotor 3B corresponds to the driven rotor. In the present invention, by utilizing such a characteristic phenomenon caused by the combination of the number of teeth, it is possible to grasp the change in the physical properties of the kneaded material, and as a result, it is possible to accurately determine the end timing.

In the present invention, the number of teeth of the pair of gears is not particularly limited as long as they are integers that are not prime to each other, but the number of teeth of the gear with the larger number of teeth is 10% of the number of teeth of the other gear. ~50% more is preferred. The number of teeth of the pair of gears is such that the rotor on the high speed side (driving rotor) returns to the same phase within 10 rotations of the rotor on the high speed side and the rotor on the low speed side (driven rotor). preferable.

FIG. 3 shows, as an example, a pair of gears in which the driving gear has 25 teeth and the driven gear has 30 teeth. In this case, the drive rotor and the driven rotor return to the same phase by rotating the drive rotor connected to the drive gear six times. FIG. 3 shows a pair of rotor shafts viewed from the gear side, showing a state in which the pair of gears are engaged. In FIG. 3, for the sake of convenience, the positions of the troughs of the driven gear with which the teeth of the drive gear mesh are indicated by circled numbers.

Returning to FIG. 1, the control unit 12 is mainly composed of a microcomputer including a well-known CPU, ROM, RAM, and the like. Sensors 10 and 11 provided in the closed kneader 1 for detecting kneading parameters are connected to a controller 12 . During kneading, the kneading parameters are input to the control unit 12 at predetermined intervals (for example, every 0.1 to 1.0 seconds) and continuously detected and stored. The control unit 12 also has various arithmetic functions.

In the present invention, the kneading parameter indicates the kneading state of the kneaded material during kneading, and is a parameter that does not appear to be periodic at first glance. Specifically, the temperature of the kneaded material, the effective value of the alternating current supplied to the motor, the value of the direct current supplied to the motor, the power consumed by the motor, the load factor of the motor, the output torque of the motor, and the Sound generated and/or vibration generated from the kneader can be used.

For example, the temperature of the kneaded material is detected by a temperature sensor 10 as shown in FIG.

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 alternating current can be calculated by dividing the maximum instantaneous value by √2. If the motor is a DC motor, the DC current value supplied to the motor is detected based on the detection signal of the current sensor.

A power value consumed by the electric motor is detected by, for example, a power sensor 11 provided in the electric motor 8 as shown in FIG. 2, and the detection signal is input to 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 equation (1).
Active power P=V·I·cos θ (1)
In the above equation (1), V is the effective value of the voltage applied to the motor, I is the effective value of the alternating current supplied to the motor, θ is the phase difference between the voltage and the current, and cos θ is the power factor.
When the motor is a direct current motor, the power consumed by the motor is represented by the product of the voltage V applied to the motor and the direct current value I supplied to the motor.

Also, the load factor of the electric motor is expressed by the following equation (2) based on the power value consumed by the electric motor and the rated value of the electric motor, for example.
Load factor (%) = [Power value consumed by motor (W)/Rated value of motor (W)] x 100

The output torque of the electric motor is detected, for example, by a torque sensor provided on the electric motor. Note that the output torque is calculated, for example, based on the electric power value consumed by the electric motor and the rotation speed or angular velocity of the electric motor. Sound generated from the kneader is detected by an acoustic sensor provided in the kneader (for example, near the kneading tank). Vibration generated from the kneader is detected by a vibration sensor provided in the kneader (for example, near the kneading tank). A well-known sensor can be used for each sensor for acquiring the kneading parameters described above. FIG. 1 shows a configuration for acquiring the temperature of the kneaded material and the power value consumed by the electric motor as kneading parameters, but the configuration is not limited to this.

As shown in FIG. 1, the control unit 12 has an analysis unit 13 that performs spectrum analysis based on input kneading parameters, and is configured to be able to evaluate changes in predetermined frequency components based on analysis results. . In addition, the control unit 12 includes a determination unit 14 that determines the end timing of kneading of the kneader based on the analysis result of the analysis unit 13, and if the determination unit 14 determines that the end time of kneading has come, and a notification unit 15 for notifying that. The analysis unit 13 may perform spectral analysis directly on the kneading parameters, or may perform spectral analysis on calculated values calculated by processing the kneading parameters (for example, the deviation between the moving average value and the current value of the kneading parameters). good. The processing in each section of the control section 12 is executed during kneading. The processing in the analysis unit 13 will be described below using graphs.

In FIG. 4, a tangential closed type kneader (see FIG. 3) having a pair of gears in which the drive gear has 25 teeth m and the driven gear has 30 teeth n is used as a kneading material. This figure shows temporal fluctuations of various parameters when kneading materials. Here, the temperature in the figure indicates the temperature of the kneaded material detected by the temperature sensor, and the power in the figure indicates the power consumed by the motor detected by the power sensor (specifically, the active power of the AC motor). ), the number of rotations in the figure indicates the number of rotations of the drive rotor, and the pressure in the figure indicates the pressure load due to the weight pressure of the pressurizing lid that suppresses the floating of the kneaded material from above the kneading tank. . In this test example, various parameters are detected by various sensors every 0.5 seconds.

In the test example of FIG. 4, kneading is controlled by a conventional method, and the end temperature of kneading is set at 120.degree. With the start of kneading, driving power is supplied to the motor portion of the electric motor, and the driving rotor rotates. In FIG. 4, kneading is performed at a rotational speed of the drive rotor of 44 rpm (=0.73 Hz). The rotational speed of the driven rotor is 36.7 rpm (=0.61 Hz). In this test example, the temperature of the kneaded material reached 120° C. after the kneading time was about 260 seconds, and it was determined that it was time to finish kneading, and the motor was stopped (that is, the supply of driving power was stopped). ing. As described above, in the conventional method, the detection value (such as temperature) detected by the sensor is used as an indicator of the end timing of kneading. However, these indices are seemingly continuous, and it is difficult to grasp changes in physical properties of the kneaded material during kneading.

On the other hand, in the present invention, periodicity is found by spectrum analysis of kneading parameters, and changes in physical properties of kneaded materials during kneading are grasped by, for example, evaluating changes in predetermined frequency components. FIGS. 5 to 8, which will be described later, show the results of spectrum analysis performed by the analysis unit 13 using the kneading parameters (power value, temperature) shown in FIG.

FIG. 5 shows the result of direct Fast Fourier Transform (FFT) of the power value consumed by the motor as spectrum analysis. FIG. 5(a) is a diagram of only power values extracted from the graph of FIG. 8.18 second moving average (MA) of the power value is also shown in the figure. This moving average line is determined based on the rotational speed r of the drive rotor. FIGS. 5(b) to 5(d) show the results of fast Fourier transform of the power values in an arbitrary time period in FIG. 5(a).

In this test example, the number of teeth of a pair of gears is 25 (=m) and 30 (=n), and the greatest common divisor greater than 1 (5 (=k)) exists between 25 and 30. The number of revolutions of the driving rotor connected to the gear having 25 teeth is 44 (=r). As a result of direct spectral analysis of the power values, a spectrum A was detected around f=(r·k)/60n=0.122 (unit: Hz), as shown in FIGS. 5(b) to 5(d). Spectrum B was also detected around 0.244 Hz, which is twice as high as 0.122 Hz. At the initial stage of kneading, spectrum B is detected most strongly (see FIG. 5(b)), and as time elapses, the strongest spectrum shifts to spectrum A (see FIG. 5(c)), and further its intensity attenuates. (See FIG. 5(d)).

The spectrum detected at the above f = (r · k) / 60n and its integral multiple (including 1 times) or 1/integer frequency is a combination of different integer tooth numbers where the pair of gears is not relatively prime It is caused by This spectrum is based on the repeated appearance of a predetermined phase in the rotating phase pattern that changes as the pair of rotors rotates, and the intensity change of the spectrum indicates the physical property change of the kneaded material at the predetermined phase. It can be said that it represents

Since the detected values (raw data) contain many low frequency components, the low frequency components are excluded from the evaluation range in FIGS. 5(b) to 5(d). The same applies to FIGS. 7B to 7D, which will be described later. From this point of view, when the kneading parameter is directly analyzed by spectrum, the spectrum to be evaluated is preferably f = (r · k) / 60n and its integral multiple (more preferably 1 to 3 times). .

Next, FIG. 6 shows the result of fast Fourier transform after processing the electric power value consumed by the electric motor as spectrum analysis. In FIG. 6, as the above processing, the power value deviation (=power value (current value)−moving average value) is obtained, and the obtained power value deviation is subjected to fast Fourier transform. The results are shown in FIGS. 6(b)-(d). Note that FIG. 6(a) is the same view as FIG. 5(a).

As shown in FIGS. 6(b) to 6(d), as main spectra, spectrum A was detected around 0.122 Hz and spectrum B was detected around 0.244 Hz. In addition, temporal changes in these spectra showed behaviors similar to those in FIGS. 5(b) to 5(d).

Next, FIG. 7 shows the result of direct fast Fourier transform of the temperature of the kneaded material as spectral analysis. FIG. 7(a) is a diagram of only the temperature extracted from the graph of FIG. The figure also shows the moving average (MA) of the temperature for 8.18 seconds. This moving average line is determined based on the rotational speed r of the drive rotor. FIGS. 7(b) to 7(d) show the results of fast Fourier transform of the temperature in an arbitrary time period in FIG. 7(a).

As shown in FIGS. 7B to 7D, spectrum A was detected around 0.122 Hz, but the shape of the spectrum was somewhat unclear. On the other hand, as shown in FIGS. 8(b) to (d), when the temperature deviation (=temperature (current value)−moving average value) is fast Fourier transformed, the spectrum A around 0.122 Hz is clear. and the attenuation of the spectrum A was well confirmed.

As shown in FIG. 4, the kneading parameters such as temperature and electric power fluctuate with a trend that accompanies a much larger time span and amount of change than the fluctuation while accompanied by fine up-and-down movements. is difficult. On the other hand, as shown in FIGS. 5 to 8, the periodicity can be found by spectrally analyzing the temperature and power values directly or after processing. Furthermore, by evaluating the change in the spectrum of the predetermined frequency component, it is possible to grasp the physical property change of the kneaded material during kneading. As a result, the evaluation method and the kneader of the present invention can accurately grasp the kneading end timing according to the kneading state. As a result, as compared with the conventional method, excessive kneading can be prevented, the energy saving property is excellent, and variations in kneading characteristics for each batch can be reduced.

5 to 8 show the results of spectral analysis of the electric power consumed by the electric motor and the temperature of the kneaded material as kneading parameters, but it is also possible to grasp changes in the physical properties of the kneaded material in the same way with other kneading parameters. can be done. For example, the effective value of the alternating current supplied to the motor, the value of the direct current 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. Analysis yields similar results.

In FIG. 1, the judging section 14 judges the kneading end timing based on, for example, f=(r·k)/60n (unit: Hz) and the change in the frequency component of an integer multiple or an integer fraction thereof. For example, when m = 25, n = 30, k = 5, r = 45 (min ^-1 ), f = 0.125 (Hz), which is an integer multiple of 0.125, 0.25, 0.375, The spectrum of 0.5 Hz and the spectrum of 0.0625, 0.03166 Hz, etc., which is a fraction of an integer, are evaluated. For example, the determination unit 14 sets an intensity threshold for a spectrum of a predetermined frequency component (for example, spectrum A in FIGS. 5 to 8), and when the intensity of the spectrum is below the threshold, kneading is performed. It can be determined that it is the end timing. In addition, a threshold value for the rate of change in intensity is set, and when the rate of change in the intensity of the spectrum falls below the threshold (that is, when the change in the intensity of the spectrum slows down), it is determined that it is time to end kneading. good too.

The notification unit 15 has a function of notifying the end of kneading. The notification means is not particularly limited, and one or a combination of means such as monitor display to the worker, notification by sound or voice, notification to the outside by communication, notification by lamp display, etc. is adopted. can.

FIG. 9 is a flow chart showing a processing procedure during kneading executed by the control unit. The processing from the start to the end in FIG. 9 is repeated at predetermined time intervals.

First, the control unit inputs kneading parameters acquired by various sensors (step S11). Examples of kneading parameters include the power value consumed by the electric motor as described above, the temperature of the kneaded material, and the like. In the following step S12, spectrum analysis is performed in the analysis section based on the kneading parameters. In step S12, the kneading parameters may be processed to calculate calculated values, and the calculated values may be used for spectrum analysis. Although the method of spectrum analysis is not particularly limited, for example, fast Fourier transform can be used.

In step S13, the judging section judges the end timing of kneading. The determination of the end timing is performed, for example, using a predetermined threshold value and the spectrum of a predetermined frequency component detected by spectrum analysis.

If it is determined in step S13 that it is not the end timing (step S13: No), the process ends. On the other hand, if it is determined that it is time to finish kneading (step S13: Yes), the supply of drive power to the motor section is stopped, and the notification section notifies the operator of the end of kneading (step S14).

The specific configurations of the evaluation method and the kneader of the present invention are not limited to the configurations shown in the above figures, and can be changed as appropriate. In the examples shown in FIGS. 4 to 8, the number of rotations of the driving rotor is constant, but the present invention can be applied even when the number of rotations (=r) varies. For example, when the rotational speed r of the driving rotor changes, the spectrum analysis may be performed after complementing the input signal. Specifically, based on data sampled at equal intervals, linear interpolation is performed between the original sampled data at intervals of a/r (a (unit: s) is a constant), and resampled data is used. , the above processing can be performed. Note that the data interpolation method is not limited to linear interpolation.

INDUSTRIAL APPLICABILITY As described above, the present invention combines a configuration in which a mechanical rotation period of the rotor is expressed in a closed kneader with a tangential rotor and spectral analysis of a predetermined kneading parameter, so that generally periodicity The periodicity is found from continuously changing kneading parameters (values) that are not recognized, and changes in the physical properties of the kneaded material are grasped by paying attention to changes in predetermined frequency components.

The kneading state evaluation method and the kneader of the present invention can grasp changes in physical properties of kneaded materials using various kneading parameters in a tangential rotor closed type kneader. It can be widely used in kneading.

1 closed type kneader 2 kneading tank 2A, 2B rotor chamber 2C rib 3A, 3B kneading rotor 4a, 4b blade 5A, 5B rotor shaft 6A, 6B bearing 7A, 7B gear 7a mounting hole 7b key groove 8 electric motor 8a circuit Part 8b Motor Part 9a Pressure Lid 9b Rod 10 Temperature Sensor 10a Detection End 11 Power Sensor 12 Control Part 13 Analysis Part 14 Judgment Part 15 Reporting Part 16 Coupling

Claims (5)

A method for evaluating the kneading state in a kneader provided with a pair of tangential rotors connected by a pair of gears and rotated at different speeds by driving an electric motor,
the gears have different non-prime integer numbers of teeth;
The evaluation method is a method in which spectrum analysis is performed based on kneading parameters detected during kneading by a sensor provided in the kneader to evaluate changes in a predetermined frequency component,
The kneading parameters are the temperature of the kneaded material, the effective value of the alternating current supplied to the electric motor, the value of the direct current supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, and the output of the electric motor. at least one selected from torque, sound generated from the kneader, and vibration generated from the kneader ;
A rotor connected to a pair of gears having m and n teeth (m<n), having a greatest common divisor k greater than 1 between m and n, and having m teeth. When the number of revolutions is r (unit: min −1 ), spectrum analysis is performed based on the kneading parameter, and f = (r · k) / 60n (unit: Hz) and its integer multiple or integer ^fraction A kneading state evaluation method characterized by evaluating changes in frequency components . 2. The method according to claim 1, wherein the evaluation method is a method of processing the kneading parameter and performing spectral analysis, and the method is characterized by spectrally analyzing a deviation between a moving average value and a current value of the kneading parameter. Evaluation method of kneading state. 3. The kneading state evaluation method according to claim 1, wherein the kneader is a kneader for kneading a non-Newtonian fluid. A kneader comprising a pair of tangential rotors connected by a pair of gears and rotated at different speeds by being driven by an electric motor,
the gears have different non-prime integer numbers of teeth;
The kneader has an analysis unit that performs spectral analysis based on kneading parameters detected during kneading by a sensor provided in the kneader,
The kneading parameters are the temperature of the kneaded material, the effective value of the alternating current supplied to the electric motor, the value of the direct current supplied to the electric motor, the power value consumed by the electric motor, the load factor of the electric motor, and the output of the electric motor. at least one selected from torque, sound generated from the kneader, and vibration generated from the kneader ;
A rotor connected to a pair of gears having m and n teeth (m<n), having a greatest common divisor k greater than 1 between m and n, and having m teeth. When the number of revolutions is r (unit: min −1 ), the analysis unit performs spectrum analysis based on the kneading parameter, f = (r · k) / 60n (unit: Hz) and its integral multiple ^or A kneader characterized by evaluating a change in a frequency component of 1/integer . 5. The kneader according to claim 4 , further comprising a judging section for judging the end timing of kneading by the kneader based on the change in the frequency component obtained by the analysis section.

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