| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of defective operation of an idle rotation speed control valve due to the presence of oil mist and a moisture content by a method wherein a discharge passage for oil mist and a moisture content is formed, during operation of an internal combustion engine, oil mist and a moisture content are always discharged togetherwith a part of air, and oil mist and a moisture content is prevented from being stored at the idle rotation speed control valve. SOLUTION: In an idle rotation speed control valve, an atmosphere chamber 42 and a negative pressure chamber 44 are formed in a valve housing 43, and flow rate regulating valves 74 and 75 which regulates flow rates of passages 69 and 70 and through which the atmosphere chamber 42 and the negative chamber 44 are intercommunicated are disposed. An auxiliary chamber 77 is formed between the atmosphere chamber 43 and the negative pressure chamber 44, the upper end part of the auxiliary chamber 77 is communicated with the negative pressure chamber 44, and the lower end part of the auxiliary chamber 77 is communicated with the atmosphere chamber 42 through a communication passage 78. |
