| 摘要 |
<p>PURPOSE:To prevent binarization of output voltage of a flow meter due to intake pulses generated in a downstream engine and change in the output voltage of the flow meter due to a drift generated in an upstream air cleaner and a duct when a thermal air flow meter is mounted on an intake system. CONSTITUTION:In a sub flow path 4 formed in a block 3 radially crossing a main flow path 2 formed in a body 1, an inlet 4a and an outlet 4c opening are placed within a half of a radius from the center of a main flow path axis while at least one or more bent parts 4e for changing a direction of the flow by 180 deg. are provided in the radial sub flow path. Since full length of the sub flow path can be sufficiently longer than length between the inlet and the outlet of the sub flow path, intake pulses in the sub flow path can be sufficiently attenuated to prevent binarization. In addition since an interval between the inlet and the outlet of the flow path is placed within a half of the radius from the main flow path axis, influence of a drift from the upstream is not likely to be given.</p> |
