Inside a tube cutting machine
A modern automatic sawing machine, like many other machines, uses many components to control the machine movements. In this article we provide an insight into the components and technology behind the machine.
PLC
Programmable Logic Controller
The heart of the control system is the PLC. Here the commands of the job are converted into signals, the right signal at the right time for the right action. The job orders can be entered by the operator or loaded from an externally linked terminal, for example an ERP (enterprise resource planning) system.
After the order has been entered into the machine, the PLC determines the order in which various actions are performed. The program checks, using sensors if al conditions okayed, before the next step is started. These checks include safety systems and operator confirmations.
Change over
An automatic sawing line is equipped with numerous moving parts to separate, transport, saw and discharge the profiles. The machine is suitable for processing different types and sizes of products and needs various change over adjustments. Most adjustments can be done fully automatically be using electric motors that, for example, adjust the height guidance. Sensors check whether the correct position has been reached, after which the next step is released.
SERVO motor
stepping / stepper motor
To get the most out of the machine, several movements are done by servo motors. A servo motor is very suitable for movements with high dynamics, load capacity, positioning and speed accuracy. The servo motor is controlled by the drive, the built-in encoder can determine its position very accurately, this information is continuously shared with the drive. The result is a system that is powerful, can move at high speed and is very accurate.
An example of the advantages of the servo technic being used, is the infeed gripper system, which feeds the tubes into the saw at a speed up-to 4 meters per second with an acceleration an deacceleration of 40 mm/s² so this is approximately 4g of G-Force when (de)acceleration and stays accurate within 0.01 mm. To put this into perspective, the fastest electric car (1020 hp) achieves ‘only’ 1.4 g at acceleration.
Open TCP/IP
Communication protocol
All movements, sensors and controls must work together in a precisely tuned interplay. For this purpose, all components are connected to the internal network in the machine, this is done by having all parts speak the same language (protocol). The network is already prepared for any external connections. This allows the sawing machine to be effortlessly connected to, for example: a deburrer or robot, all coordinated with each other and can be operated from one panel.
Software
online support
The conversion of the sawing command into the interplay of the movements is done by the software. The Bewo software in the sawing line has been further developed for years and is prepared for all conceivable options and designs. The machine can be updated with the latest software via a connection and adjustments to further optimize the process are continuously being developed.
