| 摘要 |
PROBLEM TO BE SOLVED: To permit a wide range of variable control of the swirl ratio for a swirl intake system of diesel engines employing single helical port. SOLUTION: An intake port 33 which is made of a helical port consists of a port entrance portion 18 in the inlet side, a spiral scroll portion 13 located above an intake valve 15, a throat portion 12 from the scroll portion 13 via a valve seat 19 to a cylinder 20. The scroll portion 13 and the throat portion 12 are communicated by a throat opening portion 21. The throat portion 12 consists of a throat lower wall portion 22 and a throat upper wall portion 11. The throat upper wall portion 11 is movable vertically along a valve stem 14. When the throat upper wall portion 11 moves vertically, distance T from the bottom of the valve stem boss to the valve seat 19 changes. And when the ratio T/R defined by the distance T and radius R changes, swirl ratio changes greatly. |
