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US 4,393,697 AGranted
Air flow rate measuring apparatus
AssigneeHitachi, Ltd.
InventorsKanemasa Sato, Sadayasu Ueno, Kazuhiko Miya
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AssigneeHitachi, Ltd.
InventorsKanemasa Sato, Sadayasu Ueno, Kazuhiko Miya
Estimating the term…
An air flow rate measuring apparatus having an air flow sensor and a temperature sensor which are disposed in a passage for intake air formed in the vicinity of a main air flow guide chamber in an internal combustion engine. The electric characteristics of the air flow sensor vary with the flow rate of air flowing by the sensors. The air flow sensor and temperature sensor have the same shape and the same construction. The temperature sensor is used to compensate the temperature of the air flow sensor so as to maintain the air flow sensor at a predetermined temperature. These sensors are arranged in the same plane that is at right angles to the direction in which said intake air flows. The sensors are extended parallel to each other in symmetrical relationship with respect to the center line in the above-mentioned plane. Conductor support pins to which the sensors are fixed are also arranged symmetrically with respect to the center line in the mentioned plane.
An air flow rate measuring apparatus for internal combustion engines, comprising an air flow sensor disposed in a passage through which intake air flows into said engine, and a temperature sensor disposed in said passage and adapted to compensate the temperature of said air flow sensor with respect to the measurement of the flow rate of said intake air, said air flow sensor and said temperature sensor being arranged in the same plane which is at right angles to the direction in which said intake air flows, wherein said air flow sensor and said temperature sensor are fixed at their respective end portions by conductive support pins having the same surface area and the same heat capacity.
An air flow rate measuring apparatus for internal combustion engines, comprising an air flow sensor disposed in a passage through which intake air flows into said engine, and a temperature sensor disposed in said passage and adapted to compensate the temperature of said air flow sensor with respect to the measurement of the flow rate of said intake air, said air flow sensor and said temperature sensor being arranged in the same plane which is at right angles to the direction in which said intake air flows, wherein said passage is provided with a back fire preventing member positioned to prevent said air flow sensor and said temperature sensor from being exposed directly to backfire.
An air flow rate measuring apparatus for internal combustion engines, comprising an air flow sensor disposed in a passage through which intake air flows into said engine, and a temperature sensor disposed in said passage and adapted to compensate the temperature of said air flow sensor with respect to the measurement of the flow rate of said intake air, said air flow sensor and said temperature sensor being arranged in the same plane which is at right angles to the direction in which said intake air flows, wherein said passage for said intake air is provided with a venturi chamber having an annular recess surrounding the narrowest portion thereof and a by-pass so as to allow a part of said intake air to flow therethrough, said annular recess being positioned at an outlet of said by-pass, and said air flow sensor and said temperature sensor being arranged in said by-pass.
Dependencies are inferred from the claim text.