Patent ID: 7010972

Claim:
A thermal type flow measuring instrument comprising a sensing element for sensing an air flow, an electronic circuit electrically connected to said sensing element, and a frame- or box-shaped plastic casing component for accommodating and protecting said electronic circuit, said plastic casing component being a housing constructed from plastic as an injection molded part formed by integral molding together with a connector terminal which is extended from an inside to an outside of said plastic casing component while penetrating therethrough for electrical connection of said electronic circuit to an external device, said housing further including a fixing portion molded from plastic with a metal plate inserted therein for attachment to a duct component serving as a passage through which a fluid to be measured flows, said metal plate being entirely or partially covered with the plastic, and said metal plate having an opening formed adjacent a corner of said metal plate in a plastic-covered portion thereof at a part of the corner portion where a temperature stress is larger than a temperature stress at other portions of said metal plate, said opening being filled with said plastic to thereby join the plastic on one surface of said metal plate with the plastic on an opposite surface of said metal plate.