Torque sensor for steering device

A torque sensor for a steering system, comprising:

• a first magnetic body having an open region and an unopened region facing a magnet having N and S poles arranged in an alternating manner in a circular shape in only one row to produce and absorb magnetic force lines, the magnet connected to one end of a torsion bar, wherein the first magnetic body allows the magnetic force lines to pass through the open region and induces the magnetic force lines through the unopened region, and the first magnetic body is connected to the other end of the torsion bar;
• a second magnetic body which induces the magnetic force lines having passed through the open region and transmits the magnetic force lines to the open or unopened region;
• a third magnetic body which transmits the magnetic force lines induced at and transmitted from the second magnetic body to the first magnetic body, and the magnetic force lines induced at and transmitted from the first magnetic body to the second magnetic body;
• and
• a magnetic sensing member placed between the second magnetic body and the third magnetic body to sense a change in the magnetic force lines.