APPARATUS AND METHOD FOR CHANGING PIERCER ROLL OF VERTICAL PIERCING MILL

摘要

A piercer roll exchanging apparatus for use in a vertical piercing mill, as well as a piercer roll exchange method for use with the apparatus, which can automate the exchange of piercer rolls and which are suitable for flexible manufacture of small quantities of seamless steel tubes of a variety of sizes. The apparatus comprises a traveling carrier car capable of moving while carrying upper and lower cradles thereon, and a cradle shifter mounted on the traveling carrier car. The cradle shifter shifts the upper and lower cradles from a traveling end position to the interior of a piercing mill body. The cradle shifter includes a spacer clamp for damping a cradle-to-cradle spacer and for adjusting the vertical position of the spacer, as well as a lower cradle clamp. According to the present invention, automation of piercer roll exchange work and shortening of the exchange time can be attained by means of a simple structure and without deterioration of workability. <IMAGE>