POWER STEERING DEVICE

PROBLEM TO BE SOLVED: To provide a power steering device capable of accurately detecting a steering input torque via a magnetostrictive film. SOLUTION: This power steering device 10 comprises a torque shaft 30 rotating in communication with a steering wheel, a steering gear mechanism 4 converting a movement direction of the torque shaft 30 to a steering system, a magnetostrictive film 55 provided on a surface of the torque shaft 30, and an electromagnetic coil 51 provided around the magnetostrictive film 55, and detects the steering input torque inputted to the torque shaft 30 based on an inductance change of the electromagnetic coil 51. The device comprises first and second shafts 31, 41 formed by dividing the torque shaft 30 in an axial direction, and a bending stress absorbing joint 35 for engaging the first and second shafts 31, 41 with each other and absorbing a bending stress of the torque shaft 30, and the magnetostrictive film 55 is provided on the surface of the second shaft 41. COPYRIGHT: (C)2008,JPO&INPIT