ELECTRIC HEATING UNIT AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide an electric heating unit capable of exposing the surface of a heating element to the outside of a heat insulating main body to prevent the overheated heating element without reducing the efficiency and easy to manufacture at a low cost. SOLUTION: A heating element 3 machined from a wire into a wave-form with the amplitude larger than the width of grooves 2 is provided in the grooves 2 formed on the surface of a heat insulating main body 1 mainly made of a heat insulating material, curve sections 3a on both sides in the width direction of the heating element 3 are inserted into the heat insulating main body 1 from both side faces 2 a of the grooves 2, thus the heating element 3 is integrally supported on the heat insulating main body 1 in this electric heating unit. Part of the whole surface of linear sections 3b of the heat element 3 in the grooves 2 is buried in the heat insulating main body 1 from the bottom faces 2b of the grooves 2. The remaining portion of the heating element 3 exposed to the spaces in the grooves 2 becomes heat radiation portions 3c capable of preventing the overheated heating element 3.