Air flow measuring device for internal combustion engines

摘要

A gas flow measuring mechanism having a feedback control mechanism comprising a flow detection valve and a flow control valve which are in series with each other and placed in a channel, an area flowmeter for keeping constant the difference in the pressures existing on opposite sides of said flow detection valve and determining the amount of incoming air by the opening area of the flow detection valve, a pressure-sensitive amplifier mechanism for sensing the deviation of the difference in the pressures existing on opposite sides of the flow detection valve from a set pressure difference on the basis of the displacement of a pressure setting diaphragm, and a valve opening mechanism for controlling the opening and closing of the flow detection valve, wherein a bellows enclosing a gas at a reference temperature and under a reference pressure and having an effective area equal to (effective area of pressure difference setting diaphragm)x(reference pressure difference at a reference temperature and under reference pressure) DIVIDED (pressure of enclosed gas) is interlocked to the pressure difference setting diaphragm so as to make density compensation.