To improve assemblability of a diaphragm and a case by laser welding, and to improve strength of the diaphragm.
A case body 3 is molded with a laser beam absorbing material, and a cover member 2, respective intermediate passage members 11 and 12, and a resin diaphragm 16 are molded with a laser beam-permeable material. A metal diaphragm 18 is fitted to a recessed part 17 of the resin diaphragm 16 and jointed thereto by an adhesive to form a diaphragm 15 having a two-layer structure. A piezoelectric element 19 is fixed to the upper surface 18a of the metal diaphragm 18. A surplus part 16b projecting from the metal diaphragm 18 is formed in an outer peripheral part of the resin diaphragm 16, and the resin diaphragm 16 is laser-welded to the case body 3 by making a laser beam permeate the surplus part 16b.
URANO SHUICHI
SUGIYAMA SHIGERU
Next Patent: INTERNAL COMBUSTION ENGINE, CONTROL METHOD THEREOF, AND VEHICLE