Throttle unit of engine

摘要

A bypass passage includes an inlet in communication with the upstream sides of first and second throttle valves of first and second suction passages. One valve body receiving chamber is coaxial with the inlet. First and second upstream side branch passages extend from the valve body receiving chamber. Downstream side branch passages extend from the end portions of the upstream side branch passages and are in communication with the downstream sides of the first and second throttle valves of the first and second suction passages. One bypass valve is movably received in the valve body receiving chamber and can open the first and second upstream side branch passages to be at the same opening. Reducing the number of bypass valves to one can reduce the manufacturing costs and the number of man hours for assembly of the throttle unit and can equalize the rate of air flowing through the respective bypass passages.