Variable Valve Duration Camshaft Mechanism
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Solution Overview
Problem
Existing engine valve systems face challenges in optimally varying valve opening duration based on engine operation conditions, leading to noise and vibration issues, and require complex constructions that increase production costs and reduce productivity.
Innovation Solution
A continuously variable valve opening duration apparatus with a simple construction, featuring a guide rod, bushing, insert, and worm wheel system that adjusts valve opening duration based on engine conditions, reducing noise and vibration by using a plastic insert for damping and bushings for wear prevention, and allowing integration with existing engines without excessive modification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex valve system is used to vary valve opening duration, then valve operation optimization is improved, but device complexity increases
Solution Approach 1:
The camshaft is designed with an adjustable cam position relative to the crankshaft, allowing the valve opening duration to be dynamically varied according to engine operating conditions. This dynamic adjustment capability enables optimal valve operation across different speeds and loads without requiring multiple fixed cam configurations, thereby resolving the contradiction between adaptability and device complexity.
2Adaptability or versatility
If existing engines are modified to achieve variable valve duration, then valve optimization is improved, but manufacturing cost increases
Solution Approach 1:
The adjustment mechanism is segmented into modular components including the adjustable camshaft, timing belt system, and control elements that can be independently manufactured and assembled. This segmentation allows for standardized production of individual modules that can be integrated into existing engines with minimal custom fabrication, reducing overall manufacturing costs while achieving variable valve duration capability.
3Productivity
If a simple construction is used, then productivity is improved, but noise and vibration increase
Solution Approach 1:
A timing belt is introduced as an intermediary element between the crankshaft and camshaft, serving as a flexible connection medium that absorbs vibrations and reduces noise while transmitting rotational motion. This intermediary component enables a simpler overall construction compared to rigid mechanical linkages, maintaining productivity while mitigating harmful noise and vibration effects.
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 apparatus effectively varies valve opening duration to match engine conditions, reducing noise and vibration, enhancing productivity, and lowering production costs by simplifying the design and reducing the valve train height, while maintaining strength and preventing wear.
Implementation Method 1
reducing noise and vibration by using a plastic insert for damping
Implementation Method 2
bushings for wear prevention
Data Source
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AI summary
A continuously variable valve duration apparatus includes a camshaft, a cam unit on which a cam is formed, a guide bracket including an upper guide boss, an internal wheel configured to transmit rotation of the camshaft to the cam unit, a wheel housing in which the internal wheel is rotatably inserted, wherein a guide thread is formed in a portion of the wheel housing, and of which a guide shaft is formed to be movably inserted into the upper guide boss, a worm wheel to which an internal thread engaging with the guide thread is formed in the worm wheel, and to which an external thread is formed thereon, a control shaft on which a control worm engaged with the external thread is formed, and an upper bushing mounted on a lower portion of the upper guide boss to support the guide shaft.