The use of inverter in spindle less veneer peeling machine

Along with the development of economics, people’s requirement for plywood is higher and higher. And the plywood making factories require higher quality and higher precision machines. A few years ago, Spindle veneer peeling machine are widely used by a large proportion of plywood making factories, as it has the characteristic of high production precision and the good quality finished products. But for spindle machine, it can only process the logs with a diameter higher than 200 mm. Moreover, when the diameter of the log is small, the rigidity of the log is reduced, and the quality of the rotary veneer is poor. If the remaining wood core is discarded or processed into a wood core board, the raw material is greatly wasted, thereby increasing the production cost of the veneer. Therefore, manufacturers generally use the spindle-less rotary cutting machine to re-rotate the remaining wood core, so that the raw materials are fully utilized. This article will focus on the application of the inverter control system on the spindle-less veneer  rotary cutting machine.

First, the description of the rotary cutting system

A spindleless veneer peeling machine consists of the following parts: main drive motor, gearbox, pressure gauge, feed motor, reducer, feed screw, passive roller and knife bed, tool bed displacement sensor.

The main drive motor drives the pressure roller to run at a constant speed, and the driven roller and the cutter are driven by the feed motor to operate according to the real-time diameter of the log and the set veneer thickness. The smaller the diameter, the faster the feed motor drives the knife bed, ensuring that the veneer is even and thin.

The control of the traditional veneer rotary cutting machine is mainly to adopt the method of variable frequency speed regulation of the electromagnetic governor, and the speed of the motor is changed by changing the input voltage of the controller by using a manual adjustment knob or by adjusting the cam curve. This rotary cutting method produces a plate thickness error of up to 1 mm. Therefore, it is especially important to design a system that can accurately control the speed of the rotary knife to control the thickness of the rotary cutting plate. The basic idea of system design:

(1) Establish an accurate mathematical model;

(2) Replace the original speed control system to achieve precise speed control.

Second, the advantages of using variable frequency control system

(1) The inverter adopts a 32-bit digital signal processor as the core control unit to achieve high-speed performance control;

(2) According to the detection data of the knife bed displacement sensor, the feed rate of the knife bed is calculated in real time at high speed, the thickness of the sliced veneer is uniform, the precision is high, and the surface is smooth;

(3) The cutting thickness can be set and the thickness error of 0.1 mm can meet the requirements of different specifications;

(4) Excellent speed control accuracy, low frequency torque characteristics, good field weakening control

(5) Automatically identify motor parameters and intelligently adjust to the optimal control mode

(6) Simple structure, low cost, high reliability, simple installation and debugging, and convenient operation for workers;

(7) For complex rotary cutting objects, the starting torque is large, ensuring that the motor has strong cutting force at low speed and heavy cutting and the output is even, ensuring smooth rotation and high speed stopping and restarting;

(8) Wide speed regulation range, fast cutting speed, high production efficiency, and can meet the requirements of higher board speed requirements.

The application of the frequency conversion control system on the rotary cutting machine simplifies the mechanical structure of the traditional rotary cutting machine, eliminates the error caused by the wear of the traditional mechanical equipment, improves the precision of the rotary cutting, improves the efficiency of the mechanical equipment and the utilization rate of the wood, and saves energy. The effect is remarkable and can be widely applied.