Parker Hannifin has launched a clean-line pneumatic cylinder featuring a multi-position, programmable stroke-sensing system. Designated the P1D Clean, the cylinder incorporates an internal foil-positioning sensor that eliminates external dirt traps and makes the P1D suitable for applications in the food sector.The potential for remote programming, combined with multi-position sensing of the cylinder rod position, allows food processing and packaging machine builders and end users to improve machine performance.The P1D cylinder has a smooth design that conforms to the criteria established by the European Hygienic Engineering and Design Group and to EN 1672-2:2005. This enables the P1D to be used in areas where equipment has to be suitable for intensive cleaning and resistant to a range of potentially aggressive substances. This has been achieved by the development of sensor technology that allows the sensor system to be integrated into the internal profile of the cylinder. This technology is based on a thin, robust, multi-layer strip running along the length of the cylinder.
The strip comprises a flexible, conductive magnetic foil positioned above, and separate from, a potentiometer formed from two longitudinal circuits. A permanent magnet mounted around the circumference of the piston is then used to draw the conductive layer into contact with the potentiometer so that the exact position the piston can be established as it moves. The sensor strip is fed directly to a logic and software PCB, again positioned within the cylinder profile, with a single stainless-steel M12 connector and food-industry-approved TPE seal providing a link to external control devices.
These include an optional hand-held programming unit or a conventional PLC, enabling the system to set up and be reconfigured remotely without the need to access machine components. The facility to establish up to four position signals can be set anywhere along the stroke length and changed as required; there is also scope to increase this number in future. These presets can be used to determine factors such as piston position or for enhanced control of machine sequences, deceleration of pre-start, or other machine movements. Parker will also supply cylinders preconfigured to further reduce installation times.
The P1D cylinder is fully sealed, has been tested and approved to IP67 and, where applicable, meets IP69K specification. It is also constructed to ISO 15552 dimensional standards, enabling it to be changed for existing devices. Parker has refined the external surface extrusion and end caps to ensure that the P1D is self draining and that the ingress of contamination is prevented, even when subjected to regular washdown. The P1D is available in bore sizes from 32 to 125mm with a stroke length of up to 500mm and can be supplied without the sensor system.
