Patent attributes
In a variable damper using magneto-rheological fluid that comprises a cylinder (12) filled with the fluid, a piston (16) slidably received in the cylinder and including an inner yoke (32; 62; 126), an outer yoke (31; 64, 65; 140) and a coil (34; 130), a piston rod (13) having an inner end attached to the piston and an outer end extending out of the cylinder and a magnetic valve formed in a gap between the inner and outer yokes, at least one of the outer yoke and inner yoke consisting of at least two parts that are joined to each other in an axial direction. The two piece arrangement of the inner yoke or outer yoke allows the end plates to be omitted because the gap spacer can be installed without requiring end plates, and this contributes to a compact design and a favorable damping property. Also, the manufacturing and servicing of the damper can be simplified. When end plates (134) are used, the freedom in the positioning of the coil is increased.