Patent ID: 8814027
Filing Date: 2014-08-26
Classification: B23K

Abstract:
1. A rotation tool for joining a pair of metal members which form an inner corner by abutting the pair of metal members against each other by performing friction stir welding on an inner corner portion formed by abutting the pair of metal members against each other comprising: a stirring pin to be inserted into the inner corner portion, including a tapered stirring pin portion; and a base block for supporting the stirring pin and to be brought into contact with both of the pair of metal members respectively, wherein the base block includes: a body portion having a tapered body hole that becomes thinner towards a tip of the body portion and a bearing disposed on an inner circumferential surface of the tapered body hole; and a shoulder portion mounted detachably at the tip of the body portion, wherein a tapered shoulder hole is formed at a center space inside the shoulder portion such that the tapered stirring pin portion is disposed inside the tapered body hole and the tapered shoulder hole, wherein the body portion has an opposing face, opposite to the inner corner portion, formed on the tip of the body portion, and a tip of the shoulder portion projects towards a tip side of the stirring pin beyond the opposing face.