Application of CT210 Frequency Converter in Rotary Cutting Machine

With the increasing shortage of forest resources, the comprehensive and efficient utilization of wood resources has become an important issue in front of the woodworking equipment manufacturing industry and the wood processing industry. Shenzhen Dolycon Technology Co., LTD. independently developed a rotary cutting machine touch integration solution based on the CT210 ac variable frequency drive for rotary cutting machines, precise tail tension control, and excellent emergency start and emergency stop control, etc., have won unanimous praise in the application field of medium-sized wood rotary cutting machines.

At present, the multi-layer board manufacturer basically adopts the control scheme of control text + inverter in the single board production process. The control part of the control scheme is in the text. The text calculates the rotary cutting frequency of the inverter through the position of the tool post, and then writes the frequency to the inverter through communication to achieve the purpose of controlling rotary cutting. This scheme has the following disadvantages:
1) The control interface is rough: Compared with the touch screen operation, the control text interface has poor human-computer interaction and the picture is not beautiful.
2) Separation of control and drive: The frequency of the inverter is given by text communication, and the communication signal is susceptible to interference. In the environment of strong interference, the tail feeder control is not good or even cannot operate normally.

Using the touch screen integrated control scheme, the control interface is beautiful and elegant, and the human-computer interaction is good. The rotary cutting control part is in the inverter, and the touch screen is only used for display. Even if the communication is disturbed, it will not affect the normal operation, and the system stability is better.

This article will focus on the application of the rotary cutting and touch integrated solution of Shenzhen Dolycon Technology Co., LTD. based on "touch screen + CT210 adjustable frequency drive for rotary cutting machine + CT110 cutting knife frequency conversion" on the cardless rotary cutting machine.

Features of rotary cutting machine
CT210 special frequency converter for rotary cutting machine is a special product developed by Dolycon on the CT200 frequency converter product platform. The inverter integrates the special control of the rotary cutting machine into the inverter, and has integrated control of rotary cutting, breaking and ramming. It is used for the rotary cutting of wood. It has the advantages of uniform and precise rotary cutting thickness and precise control of tail tension. It fully meets the needs of customers and can make customers switch seamlessly. Compared with similar competitive products, it has the following product functional advantages:

• Unique thickness compensation, better effect;
• Scheduled shutdown, but also more flexible business operations;
• Integrated control of rotary cutting, fixed-length breaking, and ramming shaft;
• Touch integration solution.

Control requirements of rotary cutting machine

This article only takes the requirements of the rotary cutting machine produced by a certain manufacturer as an example to illustrate the specific requirements as follows:

• Excellent human-computer interaction, beautiful and clear human-computer interface, accurate and reliable password protection;
• Good speed control accuracy, excellent low-frequency output, and even large-scale wood peeling can ensure uniform peeling thickness;
• Good field weakening control, perfect for high-speed rotary cutting;
• Excellent braking performance, emergency stop and emergency start 0.2S, fast and stable forward and reverse switching;
• Good overload capacity and environmental adaptability, high operational reliability;
• The thickness error of rotary cutting is ±0.01mm, and the error of the length of rotary cutting is ±15mm;
• Accurate statistics on the number of peeling roots and veneer sheets;
• Support joystick and man-machine interface control switching, with better reliability;

System principle and control implementation

• Press the start switch, the inverter starts to work, and the roller motor starts first (the contactor of the roller motor is controlled by the inverter output relay)
• After the roller motor is started, after the delay time of the start of the screw motor, the screw motor starts. If the fast forward switch is pressed, the tool will be fed at the fast forward speed; otherwise, the tool will be fed at the speed calculated by the actual diameter of the log (through the screw motor The input of the encoder obtains the displacement of the tool post, calculates the actual diameter of the log, and then obtains the feed speed of the screw motor according to the mathematical model). The motor stops immediately, and at the same time, the screw motor retracts the tool at the set fast-retracting speed to the cut-off position of tool retraction (set position for opening the mouth), or the tool retracts to convert the tool feed displacement, and then feeds the tool, and circulates in turn. During the retraction process, when the stop time of the roller motor is longer than the restart time of the roller motor, the roller motor will restart.
• When the screw motor is feeding, if the fast-retract switch is pressed, the tool will be quickly retracted immediately. When the tool is retracted or the tool is fed according to the diameter of the log, if the fast-forward switch is pressed, the tool will be quickly fed.
• The front travel point is also the origin return point. In the process of knife feeding and rotary cutting, when the front travel switch is encountered, the knife is automatically retracted and the origin is reset to prevent the occurrence of displacement deviation caused by interference.
• After starting to peel the log, the inverter output signal controls the slitter inverter to cut, and starts to calculate the length of the peeled wood block. When the length reaches the set cutting length, it outputs the signal again to control the slitter to convert the frequency. The cutter cuts, and then starts to calculate the length again, and the cycle is repeated.
• In the process of rotary cutting, the thickness of rotary cutting can be switched by thickness switching; when controlling the inverter of the cutting motor, the length switching can be used to switch between the set length 1 and length 2.
• Press the stop switch at any time, the inverter will stop output immediately.

System wiring
The inverter S1 receives the start signal, S2 receives the stop signal, S3 receives the fast forward signal of the tool table, S4 connects the fast backward signal of the tool table, S5 connects to the travel switch, S6 connects to the photoelectric switch, S7 connects to the emergency stop switch, and T1 connects the output of the relay to the drive roller. Control signal, T2 relay is connected to control automatic ramming signal, DO output is connected to the frequency conversion start-stop terminal of the cutter, HDI1/HDI2 is connected to the encoder A and B pulses.

System debugging steps
Debugging mainly includes several stages such as motor parameter self-learning, length/thickness adjustment, wood self-learning and tail extension adjustment.
Step 1: Self-learning of motor parameters. Input the motor parameters into the inverter, change F00.01 to 0 after input, and change F02.26 to 2 (static self-learning), and the self-learning is completed in about one minute. After self-learning, change F00.01 to 1.
Step 2: Factory parameter setting. The factory parameters include mechanical parameters such as driving roller speed, diameter, center distance, screw pitch, transmission ratio, and functional parameters such as fast forward and fast backward, compensation gain, etc., which are set according to the actual mechanical data of the manufacturer.
Step 3: User parameter setting. User parameters include parameter setting and parameter calibration functions. Parameter settings include peeling thickness, peeling length, wood core and mouth opening settings. Rotation parameter calibration includes thickness calibration, length calibration, tail extension calibration and wood self-learning functions.
The man-machine interface also supports the switching of two sets of rotary cutting thickness and cutting length, which is more convenient to use.
Step 4: Open the mouth to the maximum, and set the wood self-learning to 2 in the user parameter debugging. After starting, the wood self-learning can be performed, and the wood self-learning is completed after the automatic retraction.
Step 5: Calibration of the tail piece. If there is a deviation between the actual length of the tail piece and the set length, enter the actual length of the tail piece, and the system will automatically calibrate the tail piece compensation to complete the tail piece calibration.

Through the user help interface, the debugging steps are more clear and concise, and it is more convenient for customers to use.
With the development of control technology, Dolycon CT210 series high-performance vector vfd has been successfully applied in medium-sized wood rotary cutting machines, providing a more cost-effective inverter, which not only effectively solves the problem of the entire tail opening, but also provides a more optimized man-machine The operation interface and the more convenient debugging method greatly facilitate the user's use while improving the utilization rate of wood.