BigPatents India

A throttle valve and a throttle shaft are welded to each other. Here, the throttle valve is made of resin material having a transmission property for a laser beam and includes a convex portion on a surface thereof irradiated by the laser beam. By contrast, the throttle shaft is made of resin material having a absorption property for a laser beam. The throttle valve and the throttle shaft are disposed so that their mutual portions to be welded face each other. Laser beams are radiated from the surface of the throttle valve to the mutual portions to be welded so that the convex portion is included in a part of an irradiated region.