A control system and control method for a spinning functional masterbatch adding machine

Abstract

The present invention discloses a control system and a control method for a spinning functional masterbatch adding machine, which further includes: a first frequency converter module for controlling the flow rate of the melt flow pump, and the first frequency converter modules correspond to the melt flow pumps one by one; a second frequency converter module for controlling the rotation speed of the masterbatch adding machine; a controller, and a first communication port of the controller is electrically connected to the first frequency converter module and the second frequency converter module; after the controller acquires the current operating frequency signal of the first frequency converter module, the controller transmits the feedback output frequency signal to the second frequency converter module, and the second frequency converter module controls the rotation speed of the masterbatch adding machine. The present invention provides a control system and a control method for a spinning functional masterbatch adding machine, in which the rotation speed of the masterbatch adding machine changes with the change of the melt flow pump, so as to achieve high production efficiency and the purpose of reducing waste discharge.

Description

Technical Field

[0001] The present invention relates to the technical field of spinning, and in particular to a control system and a control method for a spinning functional masterbatch adding machine. Background Art

[0002] The spinning production line for spinnable functional fibers has 4 or 8 parts, and each part is controlled by a frequency converter to control the rotation speed of the shaft of the spinning melt flow pump through an asynchronous motor. According to the prior art, such a production line was originally equipped with a functional masterbatch adding machine, and its controller was connected to each spinning melt flow pump frequency converter by a pair of wires. Because when the output frequency of each frequency converter reaches the preset operating frequency, the electrical signal output by its Y1 terminal will change. The original control mode of the controller is to obtain the Y1 terminal signals of each melt flow pump frequency converter through the connection wires, and then use the high and low of the electrical signals as the basis for judging the start and stop of each melt flow pump. Finally, the rotation speed of the masterbatch adding machine is determined according to the start and stop numbers of the melt flow pumps in the whole production line, so as to control the addition amount of the functional masterbatch (the control system structure is as Figure 1 ), the controller obtains the corresponding on and off signals of each frequency converter before and after reaching the preset frequency from the four melt flow pump frequency converters; then the controller sends the corresponding output frequency signal to the masterbatch adding machine frequency converter through the communication port according to the received on and off signals of the four melt flow pump frequency converters, and then controls the rotation speed of the masterbatch adding machine through the motor. This control mode has the following disadvantages:

[0003] First, during the spinning production process, when the winding process at a certain part stops due to a fault, if the melt flow pump at this part continues to operate, the spinning melt discharged by the melt flow pump will become waste. However, if the corresponding melt flow pump is stopped every time there is a winding fault to reduce the waste discharge, due to the frequent start and stop of the melt flow pump, it is easy to cause fluctuations in the pressure of the extruder head, resulting in product quality problems. Therefore, in actual production, on the premise of ensuring product quality, when the winding process at a certain part stops, the production workshop requires the process personnel to reduce the rotation speed of the shaft of the melt flow pump at this part to achieve the purpose of reducing waste discharge. However, when using the above control mode of the masterbatch adding machine, because the rotation speed of the shaft of the melt flow pump at this part only decreases but does not stop, the rotation speed of the masterbatch adding machine in this mode will not decrease with the decrease of the rotation speed of the melt flow pump, resulting in uneven mixing ratio of the functional masterbatch and the main raw material before and after the reduction of the rotation speed of the melt flow pump. Therefore, in this mode, when a winding fault occurs, it is impossible to reduce the waste discharge by reducing the rotation speed of the melt flow pump shaft;

[0004] II. During the test process of developing new functional fibers, it is often necessary to adjust the rotational speed of the melt flow pump shaft according to the physical indicators of the product. Under the original masterbatch adding machine control mode, after each adjustment of the speed of the melt flow pump shaft, in order to ensure the uniformity of the mixing ratio of the functional masterbatch and the main raw material before and after speed regulation, the masterbatch flow coefficient at the corresponding part has to be calculated by the process personnel and reset, which will affect the work efficiency of the process personnel. The above situation not only exists in the process of new product development, but also occurs whenever the speed of the melt flow pump needs to be adjusted;

[0005] III. The existing controller is an early product. The minimum adjustment weight of the masterbatch in its program is 0.1 g. However, with the continuous development of new varieties of masterbatches, it is found in production that some functional fibers are more sensitive to the addition amount of the masterbatch, and the minimum adjustment weight of the masterbatch is required to be less than 0.1 g. At this time, the existing controller cannot meet the production requirements;

[0006] IV. After starting the inverter of the melt flow pump, the output signal of its Y1 terminal does not change immediately. It is necessary to wait until the output frequency rises to near the operating frequency before the output signal of the Y1 terminal changes. At this time, the masterbatch adding machine responds to the operation of the melt flow pump. That is to say, the response of the masterbatch adding machine is lagged during the speed-up process of the melt flow pump (generally more than 10 seconds), and this process will affect the product quality;

[0007] V. The original control mode does not monitor and record the control process, which is not conducive to the traceability of product quality. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a control system and a control method for a spinning functional masterbatch adding machine, in which the rotational speed of the masterbatch adding machine changes with the change of the melt flow pump, so as to achieve high production efficiency and reduce waste discharge.

[0009] In order to achieve the above object, the technical solution of the present invention is: A control system for a spinning functional masterbatch adding machine, which further includes:

[0010] A first inverter module for controlling the flow rate of the melt flow pump, and the first inverter module corresponds to the melt flow pump one by one;

[0011] A second inverter module for controlling the rotational speed of the masterbatch adding machine;

[0012] A controller, and the first communication ports of the controller are electrically connected to the first inverter module and the second inverter module;

[0013] After the controller collects the current operating frequency signal of the first inverter module, the controller calculates and transmits the feedback output frequency signal to the second inverter module, and the second inverter module controls the rotational speed of the masterbatch adding machine.

[0014] After adopting the above structure, the present invention has the following advantages compared with the prior art: The first communication port of the controller is electrically connected to the first frequency converter module and the second frequency converter module through a network cable. That is to say, the controller is connected to the communication ends of the frequency converters of each melt flow pump and the masterbatch adding machine. The controller continuously reads the current operating frequency of each melt flow pump frequency converter, calculates the corresponding frequency value through the controller, and sends it to the masterbatch adding machine frequency converter. Then, through the asynchronous motor and the reduction gearbox, the rotation speed of the masterbatch adding machine is controlled, so that the rotation speed of the masterbatch adding machine can automatically follow the change of the shaft speed of each melt flow pump. When a winding fault occurs, the shaft speed of the melt flow pump can be reduced to achieve the purpose of reducing waste discharge. At the same time, when adjusting the shaft speed of the melt flow pump, the masterbatch flow coefficient of the corresponding part does not need to be calculated and reset by the process personnel, and the production efficiency is high.

[0015] Preferably, it further includes a monitoring module. The first communication ports of the monitoring module are electrically connected to the communication lines of the first frequency converter module, the second frequency converter module, and the controller. The monitoring module is used to receive the current operating frequency signal of the first frequency converter module and the output frequency signal of the second frequency converter module. During the production process, when the controller reads the frequencies of each melt flow pump frequency converter and sends the frequencies to the second frequency converter module, the monitoring module obtains the current operating frequencies of each melt flow pump frequency converter and the second frequency converter module in a passive receiving manner through the monitoring program, and records the frequency values of each frequency converter in the form of a curve, which is equivalent to recording the input and output signals of the controller, thus facilitating the management personnel to check the working condition of the controller.

[0016] Preferably, it further includes a speed measurement board and a speed sensor module for detecting the rotation speed of the masterbatch adding machine. The speed measurement board is electrically connected to the speed sensor module. The speed sensor module transmits the collected rotation speed signal of the masterbatch adding machine to the speed measurement board for processing. The speed sensor module detects the shaft speed of the masterbatch adding machine, and the speed measurement board processes the signal from the speed sensor module and stores the processing result temporarily.

[0017] Preferably, the second communication port of the controller is electrically connected to the second communication port of the monitoring module and the speed measurement board. The controller cyclically reads the operating frequencies of the frequency converters of each melt flow pump through its first communication port, continuously reads the speed signal of the rotating shaft of the masterbatch adding machine in the speed measurement board through the second communication port, then comprehensively processes the received frequency signals of the melt flow pump frequency converters and the speed signal of the rotating shaft of the masterbatch adding machine, and then controls the frequency of the second frequency converter module, thereby controlling the rotation speed of the masterbatch adding machine. The monitoring module obtains the current operating frequencies of each melt flow pump frequency converter and the second frequency converter module in a passive reception manner through its first communication port; through the second communication port, it passively receives the speed signal of the rotating shaft of the masterbatch adding machine and records it as a curve, so that the monitoring module can record the frequencies of each frequency converter and the speed of the rotating shaft of the adding machine.

[0018] Preferably, it further includes an alarm module, and the alarm module is electrically connected to the controller, and alarms when the controller detects that the operating frequency of the first frequency converter module has not changed while the speed of the rotating shaft of the masterbatch adding machine is abnormal.

[0019] A control method includes a spinning functional masterbatch adding machine control system described in any one of the above, and it includes the following steps:

[0020] I. When starting production, set the operating frequencies of the first frequency converter module and the second frequency converter module according to the process requirements;

[0021] II. After each melt flow pump runs stably, start the masterbatch adding machine and let it run in manual mode, and complete steps such as extrusion machine waste discharge, spinning small rolls of silk, and detection respectively;

[0022] III. When the quality of the small rolls of silk in step II meets the process requirements after inspection, press the manual / automatic switching key, and the controller will enter the automatic control mode;

[0023] IV. During automatic control, the controller reads the operating frequency of a first frequency converter module every 100 ms to 300 ms through the first communication port, and continuously reads the speed signal of the rotating shaft of the masterbatch adding machine in the speed measurement board through the second communication port. When the controller detects that the operating frequency of the first frequency converter module has changed, the controller executes the main control to achieve the active adjustment of the rotation speed of the masterbatch adding machine; when the controller detects that the operating frequencies of the first frequency converter module have not changed, then execute the next step;

[0024] V. Execute the negative feedback control and alarm functions: the negative feedback control is used to correct the slow change of the rotating shaft speed of the masterbatch adding machine due to external factors, and the alarm function is used to give early warning when the masterbatch adding machine fails;

[0025] 6. The monitoring module obtains the current operating frequencies of the first frequency converter module and the second frequency converter module through its own first communication port in a passive reception manner; and passively receives the speed signal of the rotating shaft of the masterbatch adding machine through the second communication port.

[0026] 7. Repeat steps 4 to 6 until the machine stops.

[0027] After adopting the above technical solutions, the present invention has the following advantages compared with the prior art: 1. The controller reads the frequencies of each melt flow pump frequency converter and calculates the theoretical operating frequency value f S of the second frequency converter module and the target speed V 目 of the rotating shaft to make an automatic follow-up. When a winding failure occurs, the waste discharge can be reduced by reducing the rotational speed of the melt flow pump shaft; 2. The master control is used to actively adjust the rotational speed of the masterbatch adding machine and is used in the occasions where the speed of the melt flow pump needs to be adjusted to ensure that the mixing ratio of the functional masterbatch and the main raw material is uniform before and after speed regulation; 3. The controller reads the frequency of a melt flow pump frequency converter every 100 ms to 300 ms, and it takes 0.4 to 1.2 s to read four frequency converters, achieving the purpose of quickly responding to the frequency changes of each melt flow pump frequency converter. The response of the masterbatch adding machine is fast, and the influence on the product quality during the speed increase or decrease of the frequency converter can be ignored; 4. The monitoring module is used to monitor and record the control process, which is conducive to the traceability of product quality.

[0028] Preferably, the master control in step 4 refers to that the controller cyclically reads the operating frequency of each first frequency converter module through the first communication port, continuously reads the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board through the second communication port, then comprehensively processes the received first frequency converter module frequency signal and the speed signal of the rotating shaft of the masterbatch adding machine, and then controls the frequency of the second frequency converter module, thereby controlling the rotational speed of the masterbatch adding machine. When the operating frequency of the first frequency converter module changes, that is, when the speed of the melt flow pump changes, the controller immediately performs a fast and accurate applicability control on the rotational speed of the masterbatch adding machine.

[0029] Preferably, the negative feedback control refers to that the controller uses the operating frequency output to the second frequency converter module for the first time when switching from manual control to automatic control as the reference output frequency F S , then reads the frequency values of each first frequency converter module, and obtains the reference flow rate L R of the entire production line according to the formula. At the same time, it reads the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board, and uses this speed signal as the reference speed V S of the rotating shaft corresponding to the reference output frequency F 基, after determining three reference quantities, the controller enters the continuous control state. By reading the frequencies of each frequency converter and according to the formula, the actual flow rate Lr of the production line and the theoretical operating frequency value f of the second frequency converter module are determined. S and the target speed V of the rotating shaft 目 , then read the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board, and use this speed signal as the actual speed V. 实 Compare it with the target speed V_target. According to the deviation value of the speed, determine the actual operating frequency f of the second frequency converter module. For the relatively slow and small-amplitude changes in the rotation speed of the rotating shaft of the masterbatch adding machine caused by the change of the resistance it receives, it can also respond in time for correction, with high reliability.

[0030] Preferably, the alarm function means that when the controller detects that the operating frequency of the first frequency converter module has not changed, but the actual speed V of the rotating shaft of the masterbatch adding machine read from the speed measuring board 实 and the target speed V 目 When the absolute value of the difference |ΔV| ≥ M, start a timer that counts down for N minutes. If each time the controller reads the actual speed V of the rotating shaft of the masterbatch adding machine within N minutes 实 and |ΔV| ≥ M always holds, then after N minutes, the controller will drive the alarm module to give an alarm; if |ΔV| < M appears within N minutes or the controller detects that the operating frequency of the first frequency converter module has changed, then stop the timer and clear it. When the speed of the rotating shaft of the masterbatch adding machine is abnormal, it can give an alarm. If a failure occurs in the masterbatch adding machine during the production process and can be discovered and processed in time, the number of defective or waste products produced will be reduced, and then the overall production cost will be lower.

[0031] Preferably, when the controller detects that the operating frequencies of the first frequency converter module have not changed in step four, it means that the controller continuously detects five times that the operating frequency of the first frequency converter module has not changed, with high reliability. Brief Description of the Drawings

[0032] Figure 1 is the circuit schematic diagram of the present prior art.

[0033] Figure 2 is the circuit schematic diagram of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0034] Figure 3 is the schematic diagram of the controller structure of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0035] Figure 4 is the control flowchart of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0036] Figure 5 is the alarm flowchart of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0037] Figure 6 This is the wiring diagram between the controller, the monitoring module and the speed measurement board of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0038] Figure 7 This is the wiring diagram of the speed measurement board of a control system for a spinning functional masterbatch adding machine according to the present invention.

[0039] Among them, 1 is the first frequency converter module, 2 is the second frequency converter module, 3 is the controller, 4 is the monitoring module, 5 is the speed measurement board, 6 is the speed sensor module, and 7 is the alarm module. Specific Embodiment

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] As Figure 2 shown, the present invention provides a control system for a spinning functional masterbatch adding machine, including a controller 3, a first frequency converter module 1, and a second frequency converter module 2. The first frequency converter module 1 corresponds to the melt flow pump one by one and is used to control the flow rate of the melt flow pump, also called the melt flow pump frequency converter. The melt flow pump controls the flow rate by controlling the pump shaft speed; the second frequency converter module 2 is used to control the rotation speed of the masterbatch adding machine, also called the masterbatch adding machine frequency converter, specifically by controlling the rotation speed of the masterbatch adding machine through an asynchronous motor and a speed reducer; the controller 3 is electrically connected to the first frequency converter module 1 and the second frequency converter module 2 through the first communication port. The controller 3 reads the current operating frequency of each first frequency converter module 1 through the first communication port, and after calculation by the controller 3, it also sends the output frequency signal to the second frequency converter module 2 through the first communication port, and then controls the rotation speed of the masterbatch adding machine through the motor, so that the rotation speed of the masterbatch adding machine can automatically follow the change of the pump shaft speed of each melt flow pump. Specifically, taking the number of melt flow pumps as four as an example, in order to solve the problem that the existing technology responds at least ten seconds later during the speed increase process of the melt flow pump, the controller 3 reads the frequency of a melt flow pump frequency converter every 200 ms, reads four frequency converters and processes them, and the delay is about 1 s, achieving the purpose of quickly responding to the frequency change of each melt flow pump frequency converter. In addition, during the internal calculation process of the controller 3, enough digits are reserved after the decimal point of each data, at least three digits, so that the frequency accuracy sent to the second frequency converter module 2 is 0.01 Hz. When the functional fiber product is sensitive to the masterbatch addition amount, the controller 3 can also meet the production requirements.

[0042] Specifically, as Figure 3 , the controller 3 is composed of two parts: one part is used to read external signals, perform internal operations and output control signals; the other part is key input and data display, and the information exchange between the two is through I 2The CAN bus, the interrupt connection line, and the timing reset line are completed. The communication port of Controller 3 is connected to the communication ends of the frequency converters of each melt flow pump and the masterbatch adding machine via a network cable. The four connection lines on the left and right parts of Controller 3 are SCL and SDA two I 2 CAN bus, interrupt connection line INT, and timing reset line RST.

[0043] Specifically, the working process of Controller 3 is as follows: When Controller 3 is just powered on or the reset button is pressed during operation, first read out the pump supply data of each melt flow pump from the E 2 ROM. Using the smallest pump supply number (not zero) as the denominator and the pump supply data of each melt flow pump as the numerator, calculate the pump supply coefficients k1, k2, K3, k4 of each melt flow pump and display them in sequence on the display for the process personnel to confirm; then read out the operating frequency of the masterbatch adding machine stored by the controller for the latest time from the E 2 ROM and send this frequency to the second frequency converter module 2. The monitoring module 4 includes a computer with a monitoring program and two communication interface conversion boards. One communication interface conversion module is used to receive the frequency signals of each frequency converter, and the model is RS232 / 485 conversion board; the other communication interface conversion module is used to receive the shaft speed signal of the adding machine, and the model is RS232 / 422 conversion board.

[0044] Specifically, the switching process of the manual / automatic control of Controller 3: At the start of production, according to the results obtained from the test, the process personnel first set the operating frequencies of each melt flow pump and the second frequency converter module 2 according to the process requirements. After each melt flow pump runs stably, start the masterbatch adding machine and let it run in the manual mode. Complete the steps of extruder waste discharge, spinning small rolls of silk, detection, etc. When the quality of the spun small rolls of silk meets the process requirements after inspection (the small rolls of silk are the unrolled rolls), press the manual / automatic switching key, and Controller 3 will enter the automatic control mode: Controller 3 first sends the currently set control frequency to the second frequency converter module 2, and then reads the operating frequencies of each melt flow pump frequency converter completely and accurately once as the reference operating frequency F R of each frequency converter. Multiply each frequency value F R by the corresponding pump supply coefficient K to obtain the reference flow of each part, and then add the reference flows of each part to obtain the reference flow L R (Formula 1); In addition, the operating frequency output to the second frequency converter module for the first time when switching from manual control to automatic control is used as the reference output frequency F S , so as to complete the determination of the reference values required for the automatic operation of the controller. Then cyclically read the current operating frequency f r of each melt flow pump frequency converter, and the actual flow L r(Formula 2), and the theoretical operating frequency f of the second frequency converter module 2 can be calculated according to Formula 3 S . The controller continuously reads the current operating frequencies of each melt flow pump frequency converter in a loop, and after calculation by Formulas 1 and 3, the corresponding frequency value f S is sent to the second frequency converter module 2, and then the speed of the masterbatch adding machine is controlled through an asynchronous motor and a reduction box, so that the speed of the masterbatch adding machine can automatically follow the changes in the shaft speeds of each melt flow pump.

[0045] L R = F R 1 * K1 + F R 2 * K2 + F R 3 * K3 + F R 4 * K4 Formula 1

[0046] L r = f r 1 * K1 + f r 2 * K2 + f r 3 * K3 + f r 4 * K4 Formula 2

[0047] f S = L r / L R * F S Formula 3

[0048] In the above formulas: L R : The reference flow rate of the entire production line;

[0049] L r : The actual flow rate of the entire production line;

[0050] F R 1 - F R 4: The reference frequencies of the four melt flow pump frequency converters;

[0051] f r 1 - f r 4: The current frequencies of the four melt flow pump frequency converters;

[0052] K1 - K4: The pump supply coefficients of the four melt flow pumps;

[0053] F S : The reference frequency of the second frequency converter module 2;

[0054] f S : The theoretical operating frequency of the second frequency converter module 2 calculated based on the current actual operating frequencies of the four melt flow pump frequency converters.

[0055] As an embodiment, in order to verify whether the working process of the controller 3 is normal, it further includes a monitoring module 4. The first communication ports of the monitoring module 4 are electrically connected to the communication lines of the first frequency converter module 1, the second frequency converter module 2, and the controller 3. The first communication ports of the monitoring module 4 are connected to the communication lines of each melt flow pump frequency converter, the second frequency converter module 2, and the controller 3 via a network cable. During the production process, when the controller 3 reads the frequencies of each melt flow pump frequency converter and sends the frequencies to the second frequency converter module 2, the monitoring module 4 obtains the current operating frequencies of each melt flow pump frequency converter and the second frequency converter module 2 in a passive reception manner through a monitoring program, and records the frequency values of each frequency converter in the form of a curve, which is equivalent to recording the input and output signals of the controller 3, thus facilitating the management personnel to check the working condition of the new controller. Specifically, passive reception means that the controller 3 issues an instruction to read the operating frequency of the frequency converter through the network cable, and the frequency converter sends the frequency value to the controller 3. However, since the communication ports of the monitoring module 4 are connected to the communication ports of the controller 3 and the frequency converter via the network cable and the communication parameters are set the same, the monitoring device can receive both the instruction issued by the controller 3 and the frequency value sent by the frequency converter. Since the controller 3 and the frequency converter actively send information and the monitoring module 4 does not send information but only receives information, it is passive.

[0056] As an embodiment, in order to facilitate the process personnel to understand the rotation situation of the masterbatch adding machine and determine the actual execution effect of the control system, it further includes a speed measuring board 5 and a speed sensor module 6. The speed measuring board 5 is electrically connected to the speed sensor module 6. The speed sensor module 6 is used to collect the shaft speed signal of the masterbatch adding machine and then transmit this signal to the speed measuring board 5. The speed measuring board 5 can process the signal from the speed sensor module 6 using a speed measuring program and temporarily store the processing result. Specifically, the speed measuring board 5 is a speed signal detection circuit board, which includes a single-chip microcomputer (model: STC12C5616AD) and two communication chips (model: SN75176BP). It also includes a voltage stabilizing and filtering element of DC 5V, as well as an optocoupler isolation device and a resistor-capacitor element for anti-input interference. The speed pulse signal can be detected and processed through the single-chip microcomputer program. When the speed measuring board 5 receives an inquiry signal from the monitoring module 4 or the controller 3, the speed measuring board 5 sends the processed speed signal to the monitoring module 4 or the controller 3. Specifically, the speed sensor module 6 is a Hall speed sensor, and a magnet facing the Hall speed sensor is provided on the outer circumference of the shaft of the masterbatch adding machine.

[0057] As an embodiment, in order to monitor the rotation speed of the rotating shaft of the masterbatch feeder, during the initial development stage, the monitoring module 4 was connected to the speed measuring board 5 through the second communication port. The monitoring module 4 continuously read the rotation speed signal of the masterbatch feeder's rotating shaft temporarily stored in the speed measuring board 5 through the monitoring program via the second communication port and recorded it as a curve. In this way, the monitoring module 4 could record the frequencies of each frequency converter and the rotation speed of the rotating shaft of the feeder. Specifically, the monitoring module 4 was a computer with a monitoring program and two communication interface conversion boards. One was used to receive the signals of the frequency converters, and the other was used to receive the rotation speed feedback from the speed measuring board 5. (Note: Since it is impossible for the monitoring module in the modified Figure 2 to actively read the signals of the speed measuring board 5, the statement "during the initial development stage" means that the final adopted Figure 2 connection method has not been used yet, and it is still the monitoring module 4 that reads the signals of the speed measuring board. That is to say, when the controller 3 is not connected to the test board 5, the monitoring module 4 actively reads the signals of the speed measuring board 5. When the controller 3 is connected to the speed measuring board 5, the monitoring module 4 receives the signals of the speed measuring board 5 passively)

[0058] As an embodiment, it was found during use that: even when the output frequency of the second frequency converter module 2 remained unchanged, the rotation speed of the rotating shaft of the masterbatch feeder sometimes changed slowly due to external factors (such as the resistance it received). When the speed deviation persisted for a period of time without being corrected, it would affect the quality of the product. To solve this problem, the controller 3 was changed to a control chip with a dual communication port, and the second communication port of the controller 3 was connected to the second communication ports of the speed measuring board 5 and the monitoring module 4. At the same time, the control program and the monitoring program were also modified so that the monitoring module 4 no longer sent instructions to read the rotation speed of the rotating shaft to the speed measuring board 5, but instead the controller 3 actively read it. The modified control system is as shown in Figure 2 . Among them, the controller 3 cyclically reads the operating frequencies of each melt flow pump frequency converter through its first communication port, continuously reads the speed signal of the masterbatch feeder's rotating shaft in the speed measuring board through the second communication port, then comprehensively processes the received melt flow pump frequency converter frequency signal and the masterbatch feeder's rotating shaft speed signal, and then controls the frequency of the second frequency converter module 2, thereby controlling the rotation speed of the masterbatch feeder. The monitoring module 4 obtains the current operating frequencies of each melt flow pump frequency converter and the second frequency converter module 2 in a passive receiving manner through its first communication port; and receives the speed signal of the masterbatch feeder's rotating shaft passively through the second communication port. Specifically, the controller 3 is a single-chip microcomputer, and its model is STC12C5A60S2.

[0059] Specifically, to correct the rotation speed of the rotating shaft of the masterbatch adding machine, when starting up, the controller 3 is set to the manual mode. After the control and execution devices are operating normally and stably and the product indicators meet the requirements, press the manual / automatic switching key, and the controller 3 enters the automatic control mode: when the controller 3 switches from manual control to automatic control, the operating frequency output to the second frequency converter module 2 for the first time is used as the reference output frequency F S , then read the frequency values of each melt flow pump frequency converter, and obtain the reference flow rate L of the entire production line according to formula 1 R , at the same time, read the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board, and use this speed signal as the reference rotation speed V of the rotating shaft corresponding to the reference frequency F of the second frequency converter module 2 S 基 . After determining the three reference quantities, the controller 3 enters the continuous control state. By reading the frequencies of each frequency converter, determine the actual flow rate L of the production line according to formulas 2 to 4 r , the theoretical operating frequency value f of the second frequency converter module 2 S and the target rotation speed V of the rotating shaft 目 , then read the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board 5, and use this speed signal as the actual speed V to compare with the target speed V 实 目 , and determine the actual operating frequency f of the second frequency converter module 2 according to the deviation value of the speed (refer to formulas 5 - 8).

[0060] V 目 = f S / F S *V 基 Formula 4

[0061] ΔV = V 实 –V 目 Formula 5

[0062] When △V = 0, f = f S Formula 6

[0063] When △V < 0, f = f S +Δf Formula 7

[0064] When △V > 0, f = f S -Δf Formula 8

[0065] In formulas (4) - (8):

[0066] F S : Under the condition of normal production of the entire production line, the operating frequency output to the second frequency converter module 2 for the first time when the controller 3 just switches from manual to automatic control, that is, the reference frequency;

[0067] V 基 ​​: The controller 3 has just switched from manual control to automatic control. The rotation speed of the shaft when the masterbatch feeder is running normally is the reference speed.

[0068] f S : During the automatic control process, the theoretical operating frequency of the second frequency converter module 2 calculated based on the current actual operating frequencies of the four melt flow pumps' frequency converters.

[0069] V 目 : Corresponding to the theoretical operating frequency f of the second frequency converter module 2 S of the calculated rotation speed of the shaft, which is the target speed.

[0070] V 实 : In the automatic control mode, the actual speed of the shaft of the masterbatch feeder during long-term operation.

[0071] ΔV: The difference between the actual speed and the target speed of the shaft of the masterbatch feeder.

[0072] Δf: The frequency correction value of the second frequency converter module 2.

[0073] f: The actual operating frequency of the second frequency converter module 2.

[0074] Among the above parameters, the frequency correction value △f of the second frequency converter module 2 is set by the process personnel according to the actual production situation and stored in the E 2 ROM of the controller 3.

[0075] Specifically, during the production process of functional fibers, operations such as starting or stopping, accelerating or decelerating of each melt flow pump are relatively large operations. If the masterbatch feeder cannot respond in a timely manner, it will have a greater impact on the product quality. As can be seen from the above: during the automatic control process of the controller 3, corresponding to these large operations, the controller calculates the theoretical operating frequency value f of the second frequency converter module 2 by reading the frequencies of the melt flow pump frequency converters and according to Formulas 1-4 S and the target rotation speed V of the shaft 目 to make an automatic follow-up, which is the main control function of the controller 3. And it can be observed from actual production that: the change in the rotation speed of the shaft of the masterbatch feeder due to the change in the resistance it receives is usually relatively slow and the amplitude is small. Therefore, the negative feedback control of the controller 3 on the slow change of the rotation speed of the shaft of the masterbatch feeder according to Formulas 5-8 is subordinate to the main control of the controller 3 following the change of the shaft speed of each melt flow pump: when the controller 3 detects a change in the operating frequency of the melt flow pump frequency converters, it directly uses the theoretical operating frequency value f of the second frequency converter module 2 obtained from Formula 3 SIt is sent to the second frequency converter module 2 as the actual operating frequency, and the negative feedback control of the rotation speed of the masterbatch adding machine shaft is no longer executed; when the controller continuously detects that the operating frequencies of the frequency converters of each melt flow pump have not changed five times (for four flow pump frequency converters, the frequency of one flow pump frequency converter is read every 200 ms, and the first to fourth frequency converters are sequentially detected once and processed, and after a delay, it takes about 1 second, and it takes about 5 seconds to detect 5 times in a loop), the main control is not executed, but the negative feedback control of the rotation speed of the masterbatch adding machine shaft is executed according to the result of Formula 4-8. Through this design of combining the main control with the slave negative feedback control by the controller 3, the actual requirements of production control are better met. The control flow of the controller 3 is shown in Figure 4 。

[0076] As an embodiment, since the price of functional masterbatch is usually relatively expensive, if a failure occurs in the masterbatch adding machine during the production process and is not discovered and processed in time, there will be more defective or waste products produced, and then the overall production cost will be higher. Therefore, the controller 3 also adds an alarm function. It also includes an alarm module 7, and the alarm module 7 is electrically connected to the controller 3, and alarms when the controller 3 detects that the operating frequencies of the frequency converters of each melt flow pump have not changed, but the rotation shaft of the masterbatch adding machine read from the speed measuring board 5 is abnormal. Specifically, when the controller 3 detects that the operating frequencies of the frequency converters of each melt flow pump have not changed, but the actual speed V of the rotation shaft of the masterbatch adding machine read from the speed measuring board 实 and the target speed V 目 When the absolute value of the difference |△V︱≧M, a timer that counts down for N minutes is started. If |△V︱≧M always holds every time the controller 3 reads the actual speed V of the rotation shaft of the masterbatch adding machine within N minutes 实 , then after N minutes, the controller will drive the alarm module 7 to alarm; if |△V︱<M appears during the timing period or the controller 3 detects that the operating frequency of the melt flow pump frequency converter has changed, the timer is stopped and cleared. The above M is the alarm threshold for the difference between the actual speed V of the rotation shaft of the masterbatch adding machine 实 and the target speed V 目 , and N is the timing time of the timer. Both M and N are set by the process personnel according to the needs of the functional fiber varieties produced and stored in the E of the controller 2 ROM. The alarm flow of the controller 3 is shown in Figure 5 。

[0077] The controller 3 has the following functions: setting and identifying operation permissions; setting the pump supply volume of the melt flow pump; setting and controlling the frequency during manual operation of the controller; setting the frequency correction value △f of the second frequency converter module 2, the alarm threshold M for the rotation speed of the masterbatch adding machine shaft, and the timing time N of the timer; the main control that follows the frequency change of each melt flow pump frequency converter during automatic control and the negative feedback control that is subordinate to the main control; alarming for abnormal rotation speed of the masterbatch adding machine shaft.

[0078] Specifically, the wiring diagram of the controller 3 is as shown in Figure 6 , and the wiring diagram of the speed measurement board 5 is as shown in Figure 7 , where 75176 refers to the communication chip of model SN75176BP.

[0079] Specifically, the principle of the present invention is that the first communication port of the controller 3 is electrically connected to the first frequency converter module 1 and the second frequency converter module 2 through a network cable. That is to say, the controller 3 is connected to the communication terminals of the frequency converters of each melt flow pump and the masterbatch adding machine. The controller 3 continuously reads the current operating frequency of the frequency converter of each melt flow pump in a loop. After calculation by the controller, the corresponding frequency value is sent to the second frequency converter module 2, and then the speed of the masterbatch adding machine is controlled through the asynchronous motor and the speed reducer, so that the speed of the masterbatch adding machine can automatically follow the change of the shaft speed of each melt flow pump. When winding fails, the shaft speed of the melt flow pump can be reduced to reduce waste discharge. At the same time, when adjusting the shaft speed of the melt flow pump, the masterbatch flow coefficient of the corresponding part does not need to be calculated and reset by the process personnel, and the production efficiency is high.

[0080] Compared with the prior art, this technical solution additionally adds three parts: the speed sensor module 6, the speed measurement board 5, and the monitoring module 4, and correspondingly adds the speed measurement program and the monitoring program. Coupled with the main control function of the controller 3 following the frequency change of each melt flow pump frequency converter, 5 problems existing in the use of the old control system have been solved. In addition, according to the actual use situation, this technical solution develops the negative feedback control and alarm function for the rotation speed of the masterbatch adding machine shaft, making the control function of the controller 3 more perfect, better able to solve the actual problems in production, and at the same time reducing the production cost, which is exactly what other masterbatch adding machine control systems may lack. In addition, according to different production varieties, this technical solution can set the corresponding frequency correction value △f, alarm threshold M, and timing time N, improving the flexibility and adaptability.

[0081] Operation process: 1. At the start of production, set the operating frequencies of each melt flow pump and the second frequency converter module 2 according to the process requirements. 2. After each melt flow pump runs stably, start the masterbatch adding machine and let it run in manual mode to complete steps such as discharging waste from the extruder, spinning small rolls of filaments, and inspection respectively. Because every time products are produced, the physical indexes of the products need to be inspected: among them, fineness and tensile strength are basic inspection items, and there are other inspection requirements for different products. Only when the inspection indexes meet the requirements can continuous and batch production begin. Since the amount of filaments required for inspection is small, spinning small rolls of filaments can meet the inspection requirements, and there is no need to wait until the roll is full to take the filaments for inspection, so that the inspection results can be obtained more quickly. 3. When the product quality meets the requirements, press the manual / auto switch key, and the controller will enter the automatic control mode, following the main control that changes with the frequency of the frequency converter of each melt flow pump and the negative feedback control that is subordinate to the main control; an alarm will be given when the rotating speed of the shaft of the masterbatch adding machine is abnormal.

[0082] Embodiment

[0083] A control method, including a control system for a spinning functional masterbatch adding machine as described in any one of the above, which includes the following steps:

[0084] 1. At the start of production, set the operating frequencies of the first frequency converter module 1 and the second frequency converter module 2 according to the process requirements. During the internal calculation process of the controller 3, at least three digits are reserved after the decimal point for each data, so that the frequency accuracy sent to the second frequency converter module 2 is 0.01 Hz;

[0085] 2. After each melt flow pump runs stably, start the masterbatch adding machine and let it run in manual mode to complete steps such as discharging waste from the extruder, spinning small rolls of filaments, and inspection respectively;

[0086] 3. When the quality of the small rolls of filaments in step 2 meets the process requirements after inspection, press the manual / auto switch key, and the controller will enter the automatic control mode;

[0087] 4. The controller 3 reads the operating frequency of a first frequency converter module 1 every 100 ms to 300 ms (100 ms, 200 ms or 300 ms can be selected). When the controller 3 detects a change in the operating frequency of the first frequency converter module 1, the controller 3 performs the main control to actively adjust the rotating speed of the masterbatch adding machine. Specifically, the controller 3 cyclically reads the operating frequency of each first frequency converter module 1 through the first communication port, continuously reads the speed signal of the shaft of the masterbatch adding machine in the speed measuring board 5 through the second communication port, then comprehensively processes the received frequency signal of the first frequency converter module 1 and the speed signal of the shaft of the masterbatch adding machine, and then controls the frequency of the second frequency converter module 2, thereby controlling the rotating speed of the masterbatch adding machine; when the controller 3 detects that the operating frequencies of the first frequency converter modules 1 have not changed, the next step is executed;

[0088] 5. Execute negative feedback control and alarm function: Negative feedback control is used to correct the shaft speed of the masterbatch adding machine when it changes slowly due to external factors, and the alarm function is used to warn when the masterbatch adding machine fails; negative feedback control means that the operating frequency output to the second inverter module 2 for the first time when the controller 3 converts manual control to automatic control is used as the reference output frequency F S Then read the frequency value of each first inverter module 1, and obtain the reference flow rate L of the entire production line according to the formula R , and at the same time read the speed signal of the masterbatch adding machine shaft in the speed measuring board 5, and use the speed signal as the reference frequency F of the second inverter module 2 S Corresponding shaft reference speed V 基 After determining the three reference quantities, the controller 3 enters the continuous control state, and determines the actual flow rate Lr of the production line and the theoretical operating frequency value f of the second inverter module 2 by reading the frequency of each inverter according to the formula S and the target speed V of the shaft 目 , and then read the speed signal of the masterbatch adding machine shaft in the speed measuring plate 5, and use the speed signal as the actual speed V 实 With the target speed V 目 The actual operating frequency f of the second frequency converter module 2 is determined according to the speed deviation value; the alarm function refers to the actual speed V of the masterbatch adding machine shaft read from the speed measuring board 5. 实 With the target speed V 目 When the absolute value of the difference |△V︱≧M, a timer for N minutes is started. If the controller 3 reads the actual speed V of the masterbatch adding machine shaft each time within N minutes 实 After that, if |△V︱≧M is always true, then after N minutes, the controller 3 will drive the alarm module 7 to alarm; if |△V︱<M appears within N minutes or the controller 3 detects that the operating frequency of the first inverter module 1 has changed, the timer is stopped and reset; (the alarm function is executed only when the negative feedback control is running)

[0089] 6. The monitoring module 4 obtains the current operating frequency of the first inverter module 1 and the second inverter module 2 by passive reception through its first communication port; and passively receives the speed signal of the rotating shaft of the masterbatch adding machine through the second communication port;

[0090] 7. Repeat steps 4 to 6 until the machine stops.

[0091] After adopting the above technical solution, the present invention has the following advantages compared with the prior art: 1. The controller reads the frequency of each melt flow pump inverter and calculates the theoretical operating frequency value f of the second inverter module 2. S and the shaft target speed V目 Make automatic following. When winding fails, the rotational speed of the melt flow pump shaft can be reduced to achieve the purpose of reducing waste discharge; Second, use the main control to actively adjust the rotational speed of the masterbatch adding machine, which is used in occasions where the speed of the melt flow pump needs to be adjusted, to ensure that the mixing ratio of the functional masterbatch and the main raw material is uniform before and after speed regulation; Third, the controller reads the frequency of a melt flow pump frequency converter every 100 ms to 300 ms. It takes 0.4 to 1.2 s to read four frequency converters, achieving the purpose of quickly responding to the frequency changes of each melt flow pump frequency converter. The response of the masterbatch adding machine is fast, and the impact on product quality during the speed increase or decrease of the frequency converter can be ignored; Fourth, use the monitoring module to monitor and record the control process, which is conducive to the traceability of product quality; Fifth, in the internal calculation process of the controller 3, enough digits are reserved after the decimal point of each data, at least three digits, so that the frequency accuracy sent to the second frequency converter module 2 is 0.01 Hz. When the functional fiber product is sensitive to the addition amount of the masterbatch, the controller 3 can also meet the production requirements.

[0092] On the basis of the above solution, if various modifications or deformations of the present invention do not depart from the spirit and scope of the present invention, and if these modifications and deformations fall within the scope of the claims of the present invention and equivalent technical scope, then the present invention also intends to include these modifications and deformations.

Claims

1. A control method for a control system of a spinning functional masterbatch adding machine, characterized in that: It includes the following steps: First, at the start of production, set the operating frequencies of the first frequency converter module (1) and the second frequency converter module (2) according to the process requirements. Second, after each melt flow pump runs stably, start the masterbatch addition machine and let it run in manual mode, and complete steps such as extrusion machine waste discharge, small roll spinning, and detection respectively. Third, when the quality of the small roll silk in step two meets the process requirements after inspection, press the manual / auto switch key, and the controller will enter the automatic control mode. Fourth, during automatic control, the controller (3) reads the operating frequency of the first frequency converter module (1) every 100 ms to 300 ms through the first communication port, and continuously reads the speed signal of the masterbatch addition machine shaft in the speed measurement board (5) through the second communication port. When the controller (3) detects a change in the operating frequency of the first frequency converter module (1), the controller (3) executes the main control to achieve active adjustment of the rotation speed of the masterbatch addition machine; when the controller (3) detects that the operating frequencies of the first frequency converter module (1) have not changed, then execute the next step. Fifth, execute the negative feedback control and alarm functions: the negative feedback control is used to correct the rotation speed of the masterbatch addition machine shaft when it changes slowly due to external factors, and the alarm function is used to give an early warning when the masterbatch addition machine fails. Sixth, the monitoring module (4) obtains the current operating frequencies of the first frequency converter module (1) and the second frequency converter module (2) in a passive reception manner through its own first communication port; and passively receives the speed signal of the masterbatch addition machine shaft through the second communication port. Seventh, repeat steps four to six until shutdown. The control system of the spinning functional masterbatch addition machine includes: The first frequency converter module (1) is used to control the flow rate of the melt flow pump, and the first frequency converter module (1) corresponds to the melt flow pump one by one. The second frequency converter module (2) is used to control the rotation speed of the masterbatch addition machine. The controller (3), the first communication ports of the controller (3) are electrically connected to the first frequency converter module (1) and the second frequency converter module (2). After the controller (3) collects the current operating frequency signal of the first frequency converter module (1), the controller (3) calculates and transmits the feedback output frequency signal to the second frequency converter module (2), and the second frequency converter module (2) controls the rotation speed of the masterbatch addition machine.

2. The control method of a spinning functional masterbatch adding machine control system according to claim 1, characterized in that: It further includes a monitoring module (4), the first communication ports of the monitoring module (4) are electrically connected to the communication lines of the first frequency converter module (1), the second frequency converter module (2), and the controller (3), and the monitoring module (4) is used to receive the current operating frequency signal of the first frequency converter module (1) and the output frequency signal of the second frequency converter module (2).

3. The control method of a spinning functional masterbatch adding machine control system according to claim 2, characterized in that: It further includes a speed measurement board (5) and a speed sensor module (6) for detecting the rotation speed of the masterbatch addition machine. The speed measurement board (5) is electrically connected to the speed sensor module (6), and the speed sensor module (6) transmits the collected rotation speed signal of the masterbatch addition machine to the speed measurement board (5) for processing.

4. The control method of a spinning functional masterbatch adding machine control system according to claim 3, characterized in that: The second communication port of the controller (3) is electrically connected to the second communication port of the monitoring module (4) and the speed measurement board (5).

5. The control method of a spinning functional masterbatch adding machine control system according to claim 1, characterized in that: It further includes an alarm module (7), and the alarm module (7) is electrically connected to the controller (3).

6. The control method of a control system for a spinning functional masterbatch adding machine according to claim 1, characterized in that: The main control in the fourth step refers to that the controller (3) cyclically reads the operating frequency of each first frequency converter module (1) through the first communication port, continuously reads the speed signal of the masterbatch adding machine rotating shaft in the speed measuring board (5) through the second communication port, then comprehensively processes the received frequency signal of the first frequency converter module (1) and the speed signal of the masterbatch adding machine rotating shaft, and then controls the frequency of the second frequency converter module (2), thereby controlling the rotation speed of the masterbatch adding machine.

7. The control method of a control system for a spinning functional masterbatch adding machine according to claim 1, characterized in that: The negative feedback control refers to that when the controller (3) converts manual control to automatic control, the operating frequency output to the second frequency converter module (2) for the first time is used as the reference output frequency F S , then the frequency values of each first frequency converter module (1) are read, and the reference flow rate L of the entire production line is obtained according to the formula R , at the same time, the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board (5) is read, and this speed signal is used as the reference rotating shaft speed V corresponding to the reference output frequency F of the second frequency converter module (2) S 基 . After determining the three reference quantities, the controller (3) enters the continuous control state. By reading the frequencies of each frequency converter, the actual flow rate Lr of the production line, the theoretical operating frequency value f of the second frequency converter module (2) S and the target rotating shaft speed V 目 are determined. Then, the speed signal of the rotating shaft of the masterbatch adding machine in the speed measuring board (5) is read, and this speed signal is used as the actual speed V 实 to be compared with the target speed V 目 , and the actual operating frequency f of the second frequency converter module (2) is determined according to the deviation value of the speed.​ 8. The control method of a control system for a spinning functional masterbatch adding machine according to claim 1, characterized in that: The described alarm function means that when the controller (3) detects that the operating frequency of the first frequency converter module (1) has not changed, but the actual speed V of the masterbatch feeder shaft read from the speed measuring board (5) 实 and the target speed V 目 the absolute value of the difference |ΔV︱≧M, a timer that counts down for N minutes is started. If |ΔV︱≧M always holds true every time the controller (3) reads the actual speed V of the masterbatch feeder shaft within N minutes 实 then after N minutes, the controller (3) will drive the alarm module (7) to give an alarm; if |ΔV︱<M occurs within N minutes or the controller (3) detects that the operating frequency of the first frequency converter module (1) has changed, the timer is stopped and cleared.

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