A modern hardening machine with high frequency currents require
A modern hardening machine with high frequency currents requires high degree of automation. This can be achieved only by use of modern technical decisions based on programmable logic controllers (PLCs).
Standard requirements for elements of displacement and rotation in a modern hardening machine:
– horizontal and vertical move of the upper center;
– horizontal move of the table with the bottom center;
– horizontal and vertical move of the transformer with inductor;
– remote control of the position of the transformer with inductor “right-left”, “forward-backward”, “up-down”;
– remote control of the upper center position “right-left”, “forward-backward”, “up-down”;
– move and rotation must be provided by synchronous or stepper motors;
– motion system drives must have feedback on their position.
To fulfill above conditions, the PLC must be able to control 8 motors for displacement and 1 motor for rotation.
А servomotor’s driver needs a high-speed impulse control (STEP / DIR protocol). 8 high-speed PLC outputs are required for implementation of the machine control system with 8 high-precision servo motors. And 8 high-speed countable PLC inputs are required for the servomotor’s position track via the encoder.
It is possible to use a servomotor driver with an analog input for the bottom center rotation, since there’s no need in precise positioning of the motor shaft, but only required rotation speed is enough to set up.
In the summer of 2016, it was decided to find a cheap, reliable and efficient PLC with a good operator panel, free software that allows you to control at least 4 servomotors, in perspective eight ones and with the option of connecting expansion modules with analog outputs.
The choice was made. The PLCs (LX3VP-2416MT4H-A), the operator panel (LEVI700EL) and the communication cable to connect the operator panel with the PLC were bought, alltogether with the first purchase.
The first start-up showed that the equipment is in working order.
While there was an introduction to the PLC, an order was placed for an automated machine for hardening couplings. The decision was taken to create a control system for the hardening machine, based on the purchased set.
Basic requirements for the machine for hardening couplings:
– hardening is performed by inductor-sprayer and the coupling mutual displacement.
– the machine must be equipped with a device for automatic feeding couplings from the tray to the hardening position, removing the couplings after hardening and moving them to the packaging in bulk.
– after setting the machine for hardening a specific size of the couplings (installing the appropriate holder and loading the appropriate hardening program), on the operator’s command, the machine consistently hardens all couplings on the tray.
– in the absence of couplings on the tray, the machine turns off and starts only on the operator’s command.
– machine operation modes: automatic (according to the program), adjustment, manual.
Below pictures show the control system panel inside and outside, as well as an example of the screen for setting the control and heating parameters.
This set of equipment allowed to solve all tasks for automation of the machine for hardening couplings.
Control panel of the hardening machine (inside).
Control panel of the hardening machine (outside).
An example of the screen for setting heating parameters.