| 摘要 |
<p>PURPOSE:To aim at enhancement in engine output by not only providing the secondary valve which under a high load of engine on the lower course side from a throttle valve located inside an intake passage, but also providing an low speed air passage bypassing this secondary valve and installing, in this passage, an intake air switching valve which closes when the intake valve opens. CONSTITUTION:A carburettor 50 interposed in an intake passage 2 is formed with provision of a throttle valve 5 consisting of an artificially controlled throttle valve 5a and an automatic valve 5b in a piston shape which closes under a low load of engine. In this case, not only the secondary valve 6 which opens under a high-load of engine is provided but also a load speed air passage 7 of a small sectional area which bypasses this secondary valve 6 is provided. And an intake air switching valve 9 which is driven under interconnection to a crank shaft via a time adjusting chain etc. by means of a valve system can shaft for driving intake/exhaust valve is interposed in this low speed air passage 7. The switching timing of this intake air switching valve 9 is to be set in such a manner as opening when the intake valve 3 closes and closing when it opens.</p> |
