DESIGN AND EXPERIMENTAL INVESTIGATION OF AN ADDITIVELY MANUFACTURED HIGH-SPEED SWITCHING VALVE

Digital hydraulic technologies represent innovative developments in fluid power research with the prospect of replacing loss-heavy resistance-controlled valve systems and thus improving the energy efficiency of hydraulic systems. High-speed switching valves sit at the core of digital hydraulic systems. The characteristics of the valve have a dominant influence on the overall system energy efficiency and performance. Current state-of-the-art switching valve designs require a compromise on either valve resistance, maximum switching frequency, compact and lightweight design or efficient actuation. This paper presents the design and experimental analysis of a novel, additively manufactured (AM) high-speed, high-performance switching valve for the use in digital hydraulic applications. The AM-based design allows flow-optimized internal galleries for high flow rates at minimized pressure drops. An innovative valve controller operates the valve at optimal frequencies to minimize energy losses. Experimental steady-state and dynamic valve responses are presented. Flow rates of up to 90 L/min at a pressure drop of 2.3 bar were achieved. The valve was tested with switching frequencies up to 139 Hz, and the switching control algorithm was validated. Two test rig configurations were constructed to investigate the valve characteristics. Simulated and experimental results showed excellent steady-state and promising dynamic performance of the valve. The work constitutes an important contribution to the field of high-speed switching valves in presenting a high-performing AM-based design with the potential to enable viable efficient digital hydraulic systems.