Patent ID: 8820131

Claim:
A shot peening apparatus for hitting shot media against a welded part for applying a compressive stress to the welded part, the shot peening apparatus comprising: a kinetic-energy applying unit that applies kinetic energy to the shot media by an oscillator; and a surrounding unit that surrounds both a worked portion including the welded part and surroundings of the oscillator, and that confines the shot media within the surrounded region while changing a state to correspond to a shape of the worked portion, wherein the surrounding unit is configured as a rod member which is movable forward and backward in a direction from the oscillator toward the worked portion and a tip end of the rod member faces the direction from the oscillator toward the worked portion, the rod member is configured to surround both the worked portion including the welded part and the surroundings of the oscillator, a plurality of the rod members are arranged in such a manner as to prevent the shot media from passing through the surrounded region and spreading out of the surrounded region, and a forward or backward state of the surrounding unit changes to correspond to the shape of the worked portion.