Magneto-rheological valve-integrated cylinder and its application

Abstract

This paper presents a novel magneto-rheological (MR) valve-integrated cylinder and its use in manipulator operations. Conventional MR valves are flow channels that have magnetic poles and control MR fluid flow by using the apparent viscosity change created by the application of a magnetic field. The proposed MR cylinder consists of an electromagnet-mounted piston with an annular gap, a cylinder made of magnetic material, and an upstream restriction. The MR valve has an electromagnet which controls the differential pressure of a piston and the output force. The MR cylinder features a simple, compact, and low-cost structure, a long stroke, robustness against dispersed particles, a high output force that is sufficient to drive mechanical systems, and easy force control. Furthermore, in this study, to decrease fluid power loss in pipelines, a novel low base viscosity MR fluid is created by the use of low-density ferrite particles. The basic characteristics of an MR cylinder using the new MR fluid are experimentally evaluated utilizing a fabricated MR cylinder mounted onto a manipulator. Based on these results, optimally designed MR cylinders are mounted onto a manipulator and the basic validity of the system is experimentally confirmed.