Asymmetric Intake Port Structure for Engine Combustion
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Solution Overview
Problem
When two intake ports in an internal combustion engine are both in a tumble port shape, the collision of swirl components can decrease the intensity of the tumble flow, interfering with combustion efficiency.
Innovation Solution
The intake port structure includes two intake ports arranged next to each other, with specific inner wall surface orientations that guide intake air to flow in opposite directions, breaking the intensity balance between swirl components and reducing the collision's impact on tumble flow intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If two intake ports are both in the tumble port shape to increase tumble flow intensity, then the combustion speed can be increased, but the swirl components from both ports collide and interfere with the tumble flow
Solution Approach 1:
The patent applies asymmetry by configuring the first and second intake ports with different orientations. Specifically, the first intake port is oriented in a first direction while the second intake port is oriented in a second direction that is different from the first direction. This asymmetric arrangement causes the swirl components generated by each port to have different characteristics, preventing them from colliding and interfering with each other, thereby maintaining high tumble flow intensity and combustion speed
2Speed
If intake air inflow speed is increased to increase tumble flow intensity, then the combustion speed increases, but the swirl flow intensity also increases causing stronger collision between swirl components
Solution Approach 1:
By orienting the intake ports in different directions, the patent creates asymmetric swirl patterns that do not collide even at high inflow speeds. The different orientations cause the swirl components to follow different flow paths, allowing high intake air speeds to be maintained without the harmful collision effects that would normally occur
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration suppresses the decrease in tumble flow intensity due to swirl component collisions, enhancing air-fuel mixture combustion speed and engine compression.
Implementation Method 1
the intensity of turbulence of intake air can be increased, and therefore, the combustion speed can be increased
Implementation Method 2
a swirl flow along an inner peripheral surface of the cylinder might be also generated
Data Source
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AI summary
In an engine (1), when an intake valve (16) opens, a downstream end portion (61) of a first intake port (6) extends to direct to between a shade back (162a) positioned on a cylinder axis (C) side with respect to a valve stem (161) and a ceiling surface (51) facing the shade back (162a). As viewed in a section perpendicular to a direction perpendicular to an intake air flow direction, a second intake port side inner wall surface (61a) at the downstream end portion (61) of the first intake port (6) curves apart from a second intake port (7) in a direction from an exhaust side to an intake side as compared to the shape of an opposite second intake port side inner wall surface (61b) mirror-reversed to a second intake port (7) side.