Intake control apparatus of engine

Abstract

An induction system for an internal combustion engine having both main and auxiliary induction passages serving a given cylinder. The auxiliary induction passage has a substantially smaller sectional area so that a charge delivered to the cylinder through this passage will enter the cylinder at a substantially higher velocity to improve combustion and efficiency. The flow ratio between the respective passages is controlled by a throttle valve arrangement. In accordance with an embodiment of the invention, the throttle valve arrangement consists of a pair of throttle valves positioned in a common passage and rotatable in opposite directions relative to each other. This opposite rotation increases turbulence and further aids in improving combustion. In accordance with another disclosed feature, a hot spot is provided for heating both the main and auxiliary induction passages. As a still further feature, the throttle valve that controls and directs the flow into the auxiliary induction passage is disposed in such a way as to insure complete diversion of fuel into the auxiliary induction passage during this phase of the operation.