| 摘要 |
PURPOSE:To have a valve disc of a rotary valve totally closed as well as to aim at reducing the cost of production, by setting up a helical motion conversion mechanism in position between a valve shaft and the holder, in case of a rotary valve which is set in a branch passage divaricated from an inlet passage part of the suction port. CONSTITUTION:A branch passage 14 is made up in a helical type suction port and a rotary valve 18 is inserted into this branch passage 14. A helical motion conversion mechanism composed of a helical groove 30 and a pin 31 is set up in position between a valve shaft 25 and its holder 21 of the rotary valve 18. In case of engine low speed, low laod running, the branch passage 14 can be totally closed thanks to the rotary valve 18 so that powerful turning flow can be produced. What is more, since the helical motion conversion mechanism is able to be designed so simple in structure and subject to miniaturization in size, the cost of manufacturing of the rotary valve may be much reduced and it is mountable on the narrowly spaced cylinder head. |
