A draw bench, firstly used 100 years ago, is a tool used to do cold work on a metal, such as altering the form of the metal without applying heat and applying only pressure. Draw bench machines have various types, automatic draw benches, and semi automatic draw benches. A draw bench often seen in metal wire processing, can draw different ferrous metal and non ferrous metal into the desired form including round, square, rectangle, triangle, half round, L shape, oval, etc. by pushing the piece of metal or wire through a series of dies mounted on a drawplate. The draw benches in factories are classified by different sizes. Often the number of roll cylinders ranges from 6 to 12.
Now commonly roll cylinders and the take-up parts adopt ac variable-frequency to control the speed. The cylinders and dies are cooled with water, and brake devices are installed on each cylinder, to achieve rapid start and stop. According to different process, the drawing speed varies from 6 to 20 m/min. In the drawing system, tension detected devices are used to reconnoiter the real-time tension, so as to change the drawing speed dynamically to ensure high quality finished products.
Drawing speed control: the speed of the cylinder close to the take-up part is treated as speed reference, while other cylinders shall, transmit speed in turn in accordance with their mechanical position (the PID output is also passed on to the next one). The speed relation of the cylinders:
Where K=1,2,3,… Vk is the linear speed of cylinder k. dk is the draw-out diameter of die k.
In a factory usually take-up parts have two kinds of typical control modes：
Cylinders GK820 accepts various types of master command sources (Modbus, Profibus-DP, CAN-Open, Analog input, digital input, etc.) The signal of tension detected device input through analog input terminal, via which the inverter controls the speed of each cylinder via inbuilt PID output as the correction of master frequency command.
Take-up part If the diameter at full-loaded status has no big difference with the its initial status (not loaded), the standard GK820 can work very well just like for cylinders. If the diameter has relatively big change at full-loaded status, specific parameters needs be built in for the application. Contact us today for details if you have the same or similar applications.
GK820 is the high-performance series which covers an entire range of applications, particularly for demanding ones that require precise speed control, torque control and fast response, etc.
