Method for manufacturing steering device

A method for manufacturing a steering device provided with:

• a gear housing including a pinion shaft accommodation part, a rack bar accommodation part and a rack retainer accommodation part;
• a pinion shaft which is accommodated in the pinion shaft accommodation part, has a pinion tooth, and rotates integrally with a rack bar;
• the rack bar which rotates with a rotation of a steering wheel, is accommodated in the rack bar accommodation part, and has a rack tooth meshing with the pinion tooth;
• a rack retainer accommodated in the rack retainer accommodation part;
• an adjust screw provided in the rack retainer accommodation part;
• and an urging member accommodated in the rack retainer accommodation part so as to be arranged between the rack retainer and the adjust screw, wherein the rack retainer accommodation part includes a cylindrical part, a female screw part formed on an inner peripheral side of the cylindrical part and a taper part provided at an inner peripheral edge portion of the cylindrical part of an outer side end portion of a pair of end portions of the cylindrical part, the outer side end portion being located away from the rack bar accommodation part, and wherein the adjust screw includes an adjust screw main body part and a male screw part provided on an outer peripheral side of the adjust screw main body part and screwed with the female screw part, the method comprising:
• a pinion shaft assembly step of assembling the pinion shaft to the pinion shaft accommodation part;
• a rack bar assembly step of assembling the rack bar to the rack bar accommodation part;
• a rack retainer assembly step of assembling the rack retainer to the rack retainer accommodation part, the rack retainer being provided such that the rack bar is interposed between the pinion shaft and the rack retainer;
• an urging member assembly step of assembling the urging member to the rack retainer accommodation part so as to be positioned on an opposite side of the rack bar with respect to the rack retainer;
• an adjust screw screwing-in step of screwing in the adjust screw to the rack retainer accommodation part such that the male screw part of the adjust screw is screwed with the female screw part of the rack retainer accommodation part and the urging member is compressed;
• a caulking step of caulking and fixing the adjust screw and the rack retainer accommodation part such that a plastic deformation region by caulking straddles both of the female screw part and the male screw part and in a part of the female screw part or a part of the male screw part of the cylindrical part which is exposed on the opposite side of the rack retainer in a direction of a rotation axial line of the adjust screw, an area including a top of the female screw part or a top of the male screw part is caulked and fixed, the caulking step being carried out after the adjust screw screwing-in step;
• and
• a set load adjusting step of adjusting a set load, which is a force by which the rack retainer urges the rack bar, by loosening the adjust screw to reduce a screwing-in amount of the adjust screw to a point where the set load falls within a predetermined range, the set load adjusting step being carried out after the caulking step.