| 摘要 |
<p>PURPOSE:To mix secondary air with a concentrated gas mixture as uniformly as possible by a method wherein a plurality of auxiliary air intake passages of small sectional area are provided in air intake passages, respectively, and an air intake valve 24 is provided at a concentrated section of the auxiliary air intake passages, in the case of an engine provided with carburetors in each of its air intake passages. CONSTITUTION:In case where the engine is provided with the carburetors 8 in each of its air intake passages 6, the auxiliary air intake passages 21 of small sectional area are attached to the air intake passages 6 and the secondary air intake valve 24 consisting of a negative pressure chamber 28 and etc. is provided at the concentrates section of the passages 21. When the engine speed is suddenly reduced by closing throttle valves 9 during high speed operation of a vehicle, the negative air intake pressure generating in the downstream side of each of the throttle valves acts on the negative pressure chamber 28 in the valve 24 to force a diaphragm 27 downward to thereby open the valve and therefore, the secondary air flows into the passage 22 where the air is mixed with the gas mixture and then flows into a combustion chamber 5. On the other hand, the negative air intake pressure in the negative pressure chamber 28 spreads gradually into a balance chamber 31 through an orifice 29 and after a lapse of a predetermined time, the pressures exerted on both sides of the diaphragm 27 are equilibrated. Consequently, the valve 24 comes to close after a lapse of a predetermined time from the time of reducing the engine speed even during the time when the engine speed continues to be reduced or the engine is braked.</p> |
