Magnetorheological damper

A magnetorheological (MR) damper, which includes a cylinder filled with an MR fluid, a piston rod extending to an outside of the cylinder, and a magnetic generator partitioning an inside of the cylinder into a compression chamber and a rebound chamber in a state of being connected to the piston rod and generating an electromagnetic force to the inside of the cylinder, the MR damper comprising:

• a magnetic core connected to a lower end of the piston rod;
• a flux ring connected to an edge of the magnetic core, such that a side surface of the flux ring tightly contacts an inner peripheral surface of the cylinder, the flux ring being formed to vertically penetrate through a main passage between the flux ring and the magnetic core;
• a cutaway groove concavely formed at a side surface of the magnetic core and preventing a magnetic force from being unnecessarily formed at a setting portion of the main passage, such that the MR fluid is vertically bypassed during compression and rebound strokes;
• and
• a ring-shaped connection groove at the edge of the magnetic core,
• wherein the cutaway groove vertically penetrates and is formed at upper and lower sides of the magnetic core and a vertically extending side surface of the connection groove.