Abstract: A lighting device that allows efficient heat discharge from a light source while avoiding accidents such as firing due to a flammable foreign object in contact with the light source or the like and failures such as reduction in luminous efficiency due to dust or the like adhered to and accumulated on the internal surface of a lens unit.

Abstract: Provided is a method for manufacturing a caulked assembly that is capable of manufacturing the caulked assembly at a low cost, preventing reduction of the strength of a columnar body caused by a circumferential groove, preventing deformation of the columnar body, and assembling a slimmer columnar body with a plate-like body. A mounting hole 10 for inserting and assembling a columnar body 2 is provided in a metallic plate-like body 1, and a thick portion 11 is formed along an inner circumferential edge of the mounting hole 10. Thereafter, as shown in FIG. 1(a), the columnar body 2 is inserted into the mounting hole 10 of the plate-like body 1 so that the plate-like body 1 is set in an assembly position on an outer circumferential surface of the columnar body 2.