| 摘要 |
PURPOSE:To miniaturize an oxygen sensor element itself and prevent cracking thereof by securing the element to the end of a ceramic insulator, and fitting an annular body made of a heat resisting material on the periphery said ceramic insulator. CONSTITUTION:The element 21 is provided with electrodes 21b and 21c on the inside and outside surfaces of the solid electrolyte container, a protecting porous coating layer 21d provided on said electrode 21c, and a shoulder portion 21d provided on the periphery near the container opening. The inside insulating tube 22 made of ceramic insulator has a through hole serving as both an air intake hole and a lead wiring hole in the center and an end so shaped as to closely contact with the inner surface of the opening in the element 21. Moreover, an annular body 26 made of a heat resisting material such as ceramic is fitted on the periphery of the outside insulating tube 25 made of ceramic insulator, and a housing 28 is connected to the outside of said annular body 26 by caulking. By said constituion, the caulking force is not directly applied to the element in assembly. Accordingly, the defective rate lowers. |
