Method of producing liquid-cooled jacket

摘要

Provided is a method of producing a liquid-cooled jacket wherein deformation of a seal body can be minimized. A method of producing a liquid-cooled jacket constituted by fixing a seal body (30) which seals the opening (12) of a recess (11), by friction stir welding, to a jacket body (10) having a partially opening recess (11) through which heat transport fluid for transporting heat generated by a heat generating body to the outside flows, wherein the seal body (30) is mounted on a supporting surface (15a) which is formed at the peripheral edge (12a) of the opening of the recess (11) in the jacket body (10) and consists of the bottom surface of a step lower than the surface of the jacket body (10), the side surface (15b) of the step of the jacket body (10) and the outer circumferential surface (30b) of the seal body (30) are butted each other, a plasticized region (41) is formed by making one round of a rotary tool (50) which is equipped with a stir pin (52) having a length (L1) greater than the thickness (T1) of the seal body (30) round along the butting portion (40) of the side surface (15b) of the step of the jacket body (10) and the outer circumferential surface (30b) of the seal body (30), and then the seal body (30) is welded to the jacket body (10).