Intake Variable Valve Device for Combustion Engine Tumble Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine control devices rely on tumble control valves to manage tumble flow strength, which can lead to inefficient tumble flow production and increased friction loss due to biased flow diffusion and pumping loss.
Innovation Solution
A control device that uses an intake variable valve device to control the opening and closing of intake valves, prioritizing flow coefficient enhancement over tumble flow strength, allowing for three distinct drive modes to adjust tumble flow production based on engine conditions without relying on a tumble control valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a tumble control valve is used to produce a biased flow in the intake channel, then the strength of the tumble flow can be controlled, but the biased flow may be diffused before entering the cylinder and it may be difficult to efficiently produce the tumble flow
Solution Approach 1:
The patent removes the tumble control valve from the intake channel and extracts the tumble flow control function to the combustion chamber top surface. By forming intake holes directly on the combustion chamber top surface with specific area relationships (middle intake hole area smaller than the sum of opposite end intake holes), the tumble flow is generated at the source rather than attempting to transport a biased flow through the intake channel, thereby eliminating diffusion losses and improving tumble flow production efficiency.
Solution Approach 2:
The patent introduces the combustion chamber top surface as an intermediary structure between the intake channel and the cylinder. By placing intake holes and variable valve devices directly on this surface, it creates a new interface for controlling tumble flow generation, allowing precise control of flow characteristics at the point of entry into the cylinder without relying on distant valve control mechanisms.
2Measurement precision
If a tumble control valve is used to produce a biased flow in the intake channel, then the strength of the tumble flow can be controlled, but the friction loss may increase on the wall of the intake channel because of the biased flow, and as a result, the pumping loss of the internal combustion engine may increase
Solution Approach 1:
The patent extracts the tumble flow generation point from the intake channel to the combustion chamber top surface. By eliminating the need to maintain a biased flow through the intake channel, it removes the source of friction loss on the channel walls and reduces the pumping work required to overcome these losses, thereby decreasing overall energy loss.
3Measurement precision
If the area of the middle intake hole is made smaller than the sum of the areas of intake holes at opposite ends, then the tumble flow can be optimized, but the flow coefficient of the intake channel may be reduced
Solution Approach 1:
The patent applies dynamic control by equipping each intake hole with independently controllable variable valve devices. This allows the system to adaptively adjust the opening areas of different intake holes based on operating conditions, optimizing tumble flow characteristics when needed while maximizing total intake flow coefficient when required, thereby resolving the static trade-off between tumble flow optimization and flow coefficient.
Data Source
AI summary
Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.