Internal Combustion Engine Intake Structure with Oval Tumble Passage
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Solution Overview
Problem
Existing internal combustion engine intake structures face challenges in efficiently guiding intake air flow between the throttle valve and intake valve, leading to interference with the intake valve shaft and suboptimal fuel consumption performance, especially during low-load operations.
Innovation Solution
The intake structure features a partition wall forming a main passage and a tumble passage with a horizontally long oval transverse cross section, guiding intake air into the tumble passage during low-load operations, and includes a reed valve to restrict airflow to the main passage, enhancing tumble flow and reducing collision interference with the intake valve seat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the tumble passage is flattened to improve intake air flow efficiency, then the intake air can better pass through the flat passage between the intake valve and valve seat, but the valve shaft of the intake valve interferes with the intake air flow from the tumble passage
Solution Approach 1:
The intake passage is divided into a main passage and a tumble passage by a partition wall, allowing separate optimization of each passage's function and flow characteristics
Solution Approach 2:
The tumble passage cross-section is designed with asymmetric dimensions where the dimension in the passage width direction is larger than the dimension in the passage height direction, creating locally optimized flow characteristics that avoid valve shaft interference while maintaining efficient air flow
2Productivity
If the tumble passage directly faces the intake valve port to improve flow guidance, then intake air flow efficiency is improved, but the valve shaft of the intake valve interferes with the intake air flow
Solution Approach 1:
The tumble passage is designed with asymmetric cross-sectional dimensions optimized for its specific location and function, allowing it to face the intake valve port effectively while the larger width dimension accommodates the valve shaft without significant flow interference
3Productivity
If a flattened tumble passage is used to improve intake air flow, then passage efficiency is improved, but collision interference with the intake valve seat increases
Solution Approach 1:
The tumble passage cross-section is optimized with larger width than height, creating a flow pattern that reduces collision interference with the intake valve seat while maintaining efficient air flow through the passage
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 strengthens the tumble flow, promoting atomization of the air-fuel mixture, enabling rapid and lean combustion, and improving fuel consumption performance by reducing flow velocity and increasing passage efficiency.
Implementation Method 1
the intake air flow during the low-load operation of the internal combustion engine is rectified along the tumble passage having the transverse cross section formed in a horizontally long oval shape
Implementation Method 2
the longitudinal width w of the transverse cross section of the tumble passage gradually decreases, so that the passage cross-sectional area gradually decreases and the flow velocity gradually increases
Implementation Method 3
atomization of an air-fuel mixture by the tumble flow during the low-load operation is promoted, rapid combustion and lean combustion are possible
Data Source
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AI summary
Provided is an intake structure of an internal combustion engine in which an intake air flow during low-load operation easily flows along a tumble passage provided between an intake valve and an intake valve valve seat, and flows into a combustion chamber to enhance the tumble flow, thereby improving fuel consumption performance. In an intake structure of an internal combustion engine in which a main passage 6B and a tumble passage 6A are formed by a partition wall 65 that partitions an intake passage 6 provided between a throttle valve 62a and an intake valve 73 vertically along the passage direction, and intake air is guided into the tumble passage when an internal combustion engine 4 is in a low-load operation, a transverse cross section 69 of the tumble passage formed by the partition wall is formed in a horizontally long oval shape whose longitudinal direction is a passage width direction, and one end 69a in a longitudinal direction of the tumble passage in the transverse cross section 69 is oriented along a tangential direction of an opening edge 35a of the intake valve port 35, and other end 69b is oriented to gradually narrow a longitudinal width w of the transverse cross section toward the intake valve port.