超磁歪アクチュエータの磁気回路設計およびダイレクトドライブサーボ弁への応用

抄録

At present, nozzle-flapper-type servovalves are capable of being used for a wide range of flow rate control and quick response control systems for many fluid power applications. However, the users must always keep contamination levels low, due to first-stage flow leakage which has a detrimental effect upon these valves. The DDV (direct-drive servovalve) utilizing a GMM (giant magnetostrictive material) has no first-stage leakage. This paper describes the FEM (finite-element method) analysis and experimental results of a magnetic bias of the GMM, using permanent magnets to produce linear operation under an AC field. Furthermore, it is shown that the DDV exhibits high performance as a new servovalve.