AIR SUCTION PASSAGE WITH AIR FLOWMETER

• Main Authors: USUI TOSHIBUMI, KONO HIROTOSHI
• Format: Patent
• Language: English
• Published: 16.07.1990
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; MECHANICAL ENGINEERING; METERING BY VOLUME; PHYSICS; TESTING; WEAPONS

PURPOSE:To improve the measurement accuracy of a hot-wire type air flowmeter and the product yield in die-cast formation by providing a plate type rib on the external wall surface of a subordinate flow passage, constituting an L-shaped conduit, which contacts the upstream side of a main flow passage and adjusting the flow passage resistance in the subordinate flow passage. CONSTITUTION:The rib 11 is provided between wall parts 3d and 3e of the L-shaped subordinate flow passage 3 and the internal wall 2a of the main flow passage 2 in parallel to the flow direction of the main flow passage 2, so the rib 11 serves to straighten the air in the main flow passage 2. An eddy flow is therefore prevented from being generated nearby the exit 302 of the subordinate flow passage 3 and the discharge of the flow at the subordinate flow passage exit 302 is made smooth, so that turbulent variation variation of the output of a hot-wire element 30 is suppressed. Further, when the main flow passage 2 and subordinate flow passage 3 are formed by die casting in one body, a flow molten metal becomes smooth because of the presence of the rib 11 to prevent a blow hole from being formed. Further, the air flow velocity at the arrangement part of the hot-wire element 30 is optionally adjustable by an adjusting screw 12 which varies the sectional area of the subordinate flow passage 3.