Patent ID: 6706991
Filing Date: 2004-03-16
Classification: B23K

Abstract:
A welding method for a projection bolt for welding the projection bolt having a shank, a flange, and a welding projection formed on the surface of the flange opposite to the shank side, to a plate shape work, comprising the following steps of:supporting the projection bolt by a holding head provided on a moving-back-and-forth feed rod in a state that the shank of the bolt is projected from the holding head; positioning the projection bolt on the axis of a movable electrode for moving back and forth by moving the feed rod; moving forward the movable electrode having a receiving hole with a motor, which is provided with a changing mechanism changing rotation into back-and-forth movement, for receiving the shank of the projection bolt and stopping the movable electrode from moving forward at the point that the shank is inserted into the receiving hole; retreating the holding head from the axis of the movable electrode for moving back and forth while the electrode is still; and moving forward the movable electrode again and welding the projection bolt to the work after the retreat of the holding head.