Modern servo-pneumatic systems offer the same functions as their system alternatives. This is demonstrated by demanding applications such as automated mirror image welding in the production of polymer cylinders.
The strengths of the new generation of pneumatic positioning technology are made plainly apparent in applications such as automated hot plate welding. With the help of this joining technology, end caps are welded onto the ends of cylinders in the polymer cylinder manufacturing process. During an initial process step, the two plastic parts are heated up uniformly by placing them in close proximity to the hot plate. As soon as the plastic has reached the right temperature, the plate is quickly withdrawn and the two parts are joined in a controlled fashion. These two movements place exacting, but plainly different demands upon the utilized drives.
The positioning module CMAX from Festo can control pneumatic drives both with respect to position as well as the force with which they advance into the end position.
Force/position control and soft-stop
A type DGCI drive retracts the hot plate at high speed from the joining zone, but decelerates it gently when the motion sequence is completed in order to avoid damaging the delicate hot plate. The new CMPX controller is “responsible” for gentle travel into the end-position. In addition to its new option for fast, vibration-free travel between two fixed limit-stops, this controller module also makes travel to two additional positions possible without fixed limits. Two further DGCI drives are used to join the components. They have to be controlled with regard to position, as well as to the amount of force with which they travel into the end-position. A newly developed CMAX controller ensures this function. Pressure sensors in the new VPWP proportional valves continuously read out data from the cylinder chambers to the system.
Proportional valves from Festo’s VPWP series are equipped with pressure sensors. They constantly report back diagnostic data to the system. This makes monitoring the condition of servo-pneumatic drive technology easy.
The CMPX and CMAX controller modules exploit the CPX unit for valve terminals. Function integration within the electrical periphery for valve terminals provides users with many advantages. They no longer have to select, order, install and configure components and their functions separately. Instead, they receive integrated solutions from Festo. With the CPX as a central unit, price per channel is reduced by up to 50 % — and cost reductions for ordering, setup and configuration amount to more than 60 % in some cases.
In general, simplified commissioning is a significant benefit of the new servo-pneumatic systems. Additional drives can be placed into service directly via the fieldbus without third-party software. Additionally, for the first time ever an auto-identification function facilitates simple, error-free detection of interconnected system components.
Data for condition monitoring
A further important advantage of the new servo-pneumatic generation is the fact that each device within the control circuit reads out differentiated diagnostic data. The entire system can thus be efficiently monitored, and the user’s maintenance department is provided with numerous hints, indicating how they can optimize machine availability, and above all avoid unnecessary downtime.
Filed Under: Motion control • motor controls, Pneumatic equipment + components