| 摘要 |
PURPOSE:To obtain required flow-rate controlling characteristics of a valve, by making the sectional areas of valve sheets and the setting angles of stopper plates different from each other, and thereby achieving stepwise operation of the valve sheets. CONSTITUTION:A valve body 7 is formed with a inclined valve seat 7a, on which two valve sheets 8, 9 having different sectional areas are seated. Further, a stopper plate 10 for restricting the deflection of the valve sheet 8 is fixed above the sheet 8 such that its setting angle to the surface of the valve seat 7a is greater than that of a stopper plate 11 for the valve sheet 9. When the negative pressure produced in operating an engine or the like is low, the sheet 9 alone is opened to an angle corresponding to the load since the spring constant of the sheet 9 having a smaller sectional area is small than that of the sheet 8. Along with increasing of the load, the sheet 8 also begins to open, and at a certain load, the sheet 9 comes into contact with the stopper plate 11. With further increasing of the load, the sheet 8 also comes into contact with its stopper plate 10. |
