INTAKE DUCT

摘要

An intake duct is adapted to be connected to an intake port of a cylinder head. A branch pipe of the intake manifold has in it a partition extending in a direction of intake air flow, a main passage and a tumble flow passage serving as an auxiliary passage that are defined by the partition, and a valve that opens and closes the main passage. A restrictor that minimizes the cross-sectional area of the tumble flow passage is formed between the upstream end and the downstream end in the direction of intake air flow of the tumble flow passage. The cross-sectional area of the tumble flow passage decreases from the upstream end toward the restrictor and increases from the restrictor toward the downstream end.

主权项

1. An intake duct adapted to be connected to an intake port of a cylinder head, the intake duct comprising therein:
a partition extending in a direction of intake air flow; a main passage and an auxiliary passage that are defined by the partition; and a valve that opens and closes the main passage, wherein a restrictor that minimizes a cross-sectional area of the auxiliary passage is formed between an upstream end and a downstream end in the direction of intake air flow of the auxiliary passage.