Andreas Plöckinger, Bernd Winkler, Rudolf Scheidl,
"Development and Prototyping of a Compact, Fast 3/2 Way Switching Valve with Integrated Onboard Electronics"
: Proceedings of the 11th Scandinavian International Conference on Fluid Power, SICFP'09, 6-2009, ISBN: 978-91-02-7393-588-3
Development and Prototyping of a Compact, Fast 3/2 Way Switching Valve with Integrated Onboard Electronics
Sprache des Titels:
Proceedings of the 11th Scandinavian International Conference on Fluid Power, SICFP'09
Digital and switching hydraulics were successfully established for some special applications
in the automotive area. The valves used in these applications are optimized with respect to cost under the given limited lifetime requirements; their nominal flow rates are very low. This paper gives an overview of the development of a fast 3/2 way solenoid actuated spool
type switching valve. The valve features a very compact design for ease of integration, a nominal flow rate of 10 l/min @ 5 bar pressure loss, a switching time of approximately 1 to 2 ms, a powerful yet compact solenoid, and an integrated wave spring for spool actuation.
The valve’s switching performance, in particular the magnetic force characteristics, were studied by extensive simulations. For a first feasibility check of the design, the valve was manufactured in ABS (Acrylnitril-Butadien-Styrol) by a 3D printer. To check the achievable
switching time, the spool was manufactured in steel and the magnet as a laminated stack with a copper coil. The other valve components, however, were taken from the 3D printer plastic realization. In a next step the valve was produced in steel. Comparing the measurement results for the switching time without and with oil showed that there is a significant potential to reduce oil sticking and switching volume flow. By some modifications of the valve housing
and the armature design the hydraulic switching time has been reduced to approximately 1ms.
For getting such fast switching times a high coil current is needed requiring an advanced
electronics, which for a better usability is integrated part of the valve. The onboard
microcontroller controls the current and measures the voltage of the solenoid. For development purposes a TTL interface is provided, but also CAN interface is implemented. The CAN bus is popular in industrial environment, since in future a bus control of several valves will become more and more standard.