Development of High-Speed On–Off Valves and Their Applications

With the widespread application of the computer and microelectronic technology in the industry, digitization becomes the inevitable developing trend of the hydraulic technology. Digitization of the hydraulic components is critical in the digital hydraulic technology. High-speed on-off valves (HSVs) which convert a train of input pulses into the fast and accurate switching between the on and off states belong to widely used basic digital hydraulic elements. In some ways, the characteristics of the HSVs determine the performance of the digital hydraulic systems. This paper discusses the development of HSVs and their applications. First, the HSVs with innovative structures which is classified into direct drive valves and pilot operated valves are discussed, with the emphasis on their performance. Then, an overview of HSVs with intelligent materials is presented with considering of the switching frequency and flow capacity. Finally, the applications of the HSVs are reviewed, including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.