Continuous Variable Valve Duration Camshaft Mechanism
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Solution Overview
Problem
Existing continuous variable valve lift (CVVL) and variable valve timing (CVVT) systems are complex and costly, failing to efficiently vary valve opening duration based on engine operation conditions.
Innovation Solution
A continuous variable valve duration apparatus with a camshaft, variable phase cams, sliding brackets, and a controller using an eccentric control shaft and worm gear to adjust the relative positions of slider housings, allowing for simple and efficient variation of valve opening duration based on engine conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If general CVVL and CVVT systems are used to achieve optimal valve operation depending on engine speed, then valve timing and lift can be adjusted, but the construction becomes complicated and manufacturing cost increases
Solution Approach 1:
The patent combines the camshaft and slider housing into a single integrated component, eliminating the need for separate CVVL and CVVT mechanisms. The camshaft directly houses the slider that adjusts valve duration, merging multiple functions into one component and thereby reducing construction complexity while maintaining adaptability.
Solution Approach 2:
The camshaft is designed to perform multiple functions: it provides the primary cam profile for valve actuation, houses the slider mechanism for duration control, and incorporates the eccentric control shaft for timing adjustment. This multi-functional design eliminates the need for separate dedicated mechanisms, reducing overall system complexity.
2Adaptability or versatility
If general CVVL and CVVT systems are used to achieve optimal valve operation depending on engine speed, then valve timing and lift can be adjusted, but manufacturing cost increases
Solution Approach 1:
By merging the camshaft and slider housing into a single component, the number of parts requiring manufacturing, assembly, and quality control is reduced. This integration simplifies the manufacturing process and lowers production costs while maintaining the ability to adjust valve operation parameters.
Solution Approach 2:
The patent uses a single camshaft design where parameter changes (valve duration and timing) are achieved through the position of the slider and eccentric control shaft rather than requiring multiple different camshafts or complex mechanisms. This approach simplifies manufacturing by standardizing the base component while allowing flexible parameter adjustment.
3Adaptability or versatility
If existing engines are modified to implement valve duration control, then optimal valve operation can be achieved, but modification complexity and production time increase
Solution Approach 1:
The integrated camshaft-slider design functions as a complete assembly that can be installed as a single unit in existing engines. This reduces the number of separate modifications required and simplifies the installation process, thereby maintaining production efficiency while enabling valve duration control.
Solution Approach 2:
The camshaft design is made universal by incorporating all necessary adjustment mechanisms within itself, allowing it to be adapted to existing engines without requiring extensive modifications to the engine block or other components. This universality facilitates easier integration and maintains productivity.
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
The solution reduces the size and complexity of the valve train, enhances productivity by allowing application to existing engines with minimal modification, and lowers production costs while effectively varying valve opening duration according to engine operation conditions.
Implementation Method 1
one worm gear engaged with the worm wheel and one control motor selectively rotating the worm gear for changing relative positions of the sliding housings
Implementation Method 2
one eccentric control shaft inserted into the control slot
Data Source
AI summary
A continuous variable valve duration apparatus may include a camshaft, a first and second cam portions, first and inside brackets transmitting rotation of the camshaft to the first and second cam portions respectively, a slider housing of which the first and second inside brackets are rotatably inserted thereto, cam caps of which each cam cap engaging portion is rotatably connected thereto, a connecting bracket connecting the cam caps and of which a guide opening for the guide protruded portion to be inserted thereto for guiding movement of the slider housing is formed thereto, a slider pin rotatably inserted into the first sliding opening and slidably inserted into the camshaft, a cam pin of which a cam opening for the cam to be slidably inserted thereto is formed and rotatably inserted into the second sliding opening and a controller selectively changing a position of the slider housing.