PURPOSE: To provide a short length of the axial direction within a valve box by allowing the end diameter of the driving axis to press in the inner diameter of a valve body and to incorporate the valve body and the driving axis as one body.

CONSTITUTION: The end of a driving axis 4 is fitted in the press fit section of a ring shape sleeve 3 positioned at the bottom of the valve body, allowing said end section to act as a sleeve, and incorporating said valve body 1 and a driving axis 4 as one boby fitted by press-in force. Besides, the fitted end section of said driving axis 4 may be used as an oil sealing material of the end of the valve body 1, allowing the length of axial direction within the valve chamber to make short, and enabling to facilitate the power steering to mount on the car.