TWO-WAY MAGNETORHEOLOGICAL FLUID VALVE ASSEMBLY AND DEVICES UTILIZING SAME

摘要

A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux phi , a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux phi which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating "rheology" changes causing restriction in flow of MR fluid (44) therethrough. In one aspect, a one-way check valve (34) is operative with a passive passageway (36) which is arranged in parallel relationship to the controllable passageway (42) provides "asymmetric" damping across the controllable valve (18) creating higher pressure differentials in a first direction and a lower in a second direction without "rapidly switching" the current to the coil (46). In another aspect, "asymmetric" damping is provided by a "changeable gap" formed by a moveable wall portion of the controllable passageway (42). In a third aspect, a first controllable passageway provides controllable flow in a first direction and a second controllable passageway provides controllable flow in a second direction, thereby provide "asymmetry." In a fourth aspect, "asymmetry" is provides by a "variable magnetic short" which changes magnetic circuit reluctance dependent on flow direction.