Sector gear combined machining device and machining method

The invention belongs to the field of gear machining, and particularly relates to a combined machining device and method for a sector gear. The device comprises a gear shaping cutter handle, a fan-shaped gear shaping cutter, a base, a clamp cone, a positioning expansion sleeve, a cover plate and a compression bolt. The base is arranged on a machine tool, the clamp cone is arranged in the center of the base, the outer side face of the clamp cone is a conical face, a threaded hole is formed in the center of the upper end face of the clamp cone, an inner hole of the expansion sleeve is a conical hole matched with the conical face, the clamp cone is sleeved with the expansion sleeve, and the cover plate is arranged above the expansion sleeve. A part to be machined is arranged outside the expansion sleeve in a sleeving mode and placed on the base. The compression bolt penetrates through the cover plate and is screwed in the threaded hole of the clamp cone, so that the expansion sleeve and the clamp cone are compre