Hydraulic switching valves are vital components commonly used in hydraulic applications. In a simple configuration, the valve has two states, open and closed. A spring pushes a spool into its first position and typically an electro-magnetic actuator working against the spring force is used to pull the spool into its second position.
Shape Memory Alloys (SMA’s) are known as actuators with very high energy density. This fact allows for the construction of very light weight and compact systems. The focus of this work is to replace the traditionally used electro-magnetic actuator in a hydraulic switching valve with an SMA wire actuator. This will allow for a reduction in the construction space and weight of the switching valve.
This work begins with an evaluation of the force and stroke requirements of a commercially available magnetic valve. Based on this information a new valve design using SMA wires is constructed to meet the same performance requirements. Once designed and fabricated, the SMA based valve is evaluated with respect to force and stroke. Finally both valves are arranged with other hydraulic components in a test station for direct performance comparison. The results concerning the hydraulic parameters like pressure and flow rate are compared to the conventional valve. In conclusion, the experimental results are displayed and an outlook on future work and possible application scenarios is given.
