Continuous Variable Valve Duration Camshaft Mechanism
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Solution Overview
Problem
Existing continuous variable valve systems for internal combustion engines are complex and costly due to their design, which complicates achieving optimal valve operation based on engine rotation speed with fixed valve opening durations.
Innovation Solution
A continuous variable valve duration apparatus with a simplified construction, featuring a camshaft, inner wheel, wheel housing, slider, control shaft, and guide portion, allows for varying valve opening durations based on engine operation conditions by adjusting the relative position of the wheel housing and camshaft, reducing the overall size and complexity of the valve train.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If general CVVT apparatus is used to change valve timing, then valve timing can be adjusted based on engine speed, but the valve opening duration remains fixed and the construction becomes complex
Solution Approach 1:
The patent implements a dynamic valve duration control mechanism where the camshaft's rotational speed can be varied independently from the crankshaft using a variable speed transmission mechanism. This allows the valve opening duration to change dynamically based on engine operating conditions, transforming a static system into a dynamic one that adapts to different requirements.
Solution Approach 2:
The camshaft assembly is designed to perform multiple functions: it provides both valve timing control and valve duration control through a single integrated mechanism. The variable speed transmission mechanism enables the camshaft to simultaneously adjust timing and duration, reducing the need for separate control systems and simplifying the overall construction.
2Adaptability or versatility
If multiple cams and CVVL are used to achieve optimal valve operation, then valve lift can be changed based on engine speed, but the manufacturing cost increases
Solution Approach 1:
The patent combines valve timing control and valve duration control into a single camshaft-driven mechanism with variable speed transmission. This merging of functions eliminates the need for separate CVVL mechanisms or multiple camsets, thereby reducing manufacturing complexity and cost while maintaining the ability to adjust valve operation parameters.
Solution Approach 2:
Instead of using multiple physical cams with different profiles, the system achieves variable valve lift and duration by changing the rotational speed parameter of the camshaft relative to the crankshaft. This parameter-based control approach simplifies manufacturing compared to producing and managing multiple cam components.
3Reliability
If existing engine is modified to achieve optimal valve operation, then valve performance can be optimized, but the modification complexity and cost increase
Solution Approach 1:
The variable speed camshaft mechanism is designed as a universal solution that can be integrated into existing engine architectures with minimal modification. The single mechanism handles both timing and duration control, making it adaptable to various engine types without requiring extensive customizations.
Solution Approach 2:
The valve train is segmented into independent controllable units with the variable speed transmission mechanism allowing individual camshaft control. This segmentation enables modular installation and integration into existing engines, reducing overall modification complexity.
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 solution enables optimal valve operation with reduced manufacturing costs and enhanced productivity by allowing the apparatus to be applied to existing engines with minimal modifications, thereby improving engine performance and reducing production expenses.
Implementation Method 1
an inner wheel configured to transmit rotation of the camshaft to the cam unit
Implementation Method 2
a control shaft on which an eccentric cam inserted into the slider control aperture is formed and a controller configured to selectively rotate the control shaft to move the wheel housing perpendicular to the camshaft via the slider
Implementation Method 3
a camshaft, a cam unit on which a cam is formed and of which the camshaft is inserted thereto
Data Source
AI summary
A continuous variable valve duration apparatus is provided. The apparatus includes a camshaft and a cam unit on which a cam is formed. The camshaft is inserted into the cam unit. An inner wheel transmits rotation of the camshaft to the cam unit. The inner wheel is rotatably inserted in a wheel housing a housing hinge aperture parallel to the camshaft is formed on the wheel housing. A slider hinge aperture and a slider control aperture parallel to the camshaft are formed through a slider. A hinge shaft is inserted into the housing hinge aperture and the slider hinge aperture. An eccentric cam is formed on a control shaft and is inserted into the slider control aperture. A controller selectively rotates the control shaft to move the wheel housing perpendicular to the camshaft via the slider.