Engine intake system

Abstract

An engine intake system is provided that includes a sensor unit () formed by mounting a throttle sensor () and a negative pressure sensor () on a sensor housing () mounted on a mounting face () on one side of a throttle body (), and a negative pressure transmission path () providing communication between an intake path () and the negative pressure sensor () is formed in a crank shape from a first passage () having one end opening on a peripheral face of an upper half of the intake path () in proximity to a horizontal plane (H) containing the axis of the intake path (), a groove-shaped second passage () formed between mating faces of the throttle body () and the sensor housing () so as to extend while bending upward from the other end of the first passage () at substantially right angles, and a third passage () formed in the throttle body () so as to extend from the upper end of the second passage () in a direction opposite to the first passage () and reach the negative pressure sensor (). It is thus possible to prevent fuel, foreign matter such as carbon, or blow-back gas from entering the negative pressure sensor via the negative pressure transmission path.