| 摘要 |
<p>PROBLEM TO BE SOLVED: To restrain generation of abnormal sound caused by supply of air to a secondary chamber by differing the valve opening pressure between a first check valve and a second check valve constituting two supply passages extending from a primary chamber to the secondary chamber. SOLUTION: Taking the valve opening pressure of a first check valve D1 connected to a primary chamber A1 through an orifice E1 as a reference, the valve opening pressure of a secondary check valve D2 connected to the primary chamber A1 through a second orifice E2 is set about 150% to 500%. Thus, the supply of air from the primary chamber A1 to the secondary chamber A2 is concentrated on the first check valve D1. Accordingly, the supply of air to the secondary chamber A2 is mainly performed through the passage with the first check valve D1. When the supply flow rate of the first check valve D1 is short, the second check valve D2 is opened to secure the supply of air. Therefore, two check valves are alternately opened to restrain generation of abnormal sound.</p> |
