Continuous Variable Valve Duration Apparatus with Worm Drive Mechanism
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Solution Overview
Problem
Existing continuous variable valve systems for internal combustion engines are complex and costly due to their construction, making them inefficient in varying valve opening duration based on engine operation conditions.
Innovation Solution
A simplified continuous variable valve opening duration apparatus that includes a camshaft, inner wheel, worm wheel, and control shaft, allowing for adjustable valve opening duration through a compact design that can be integrated into existing engines with minimal modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If general CVVT apparatus is used to change valve timing, then valve timing operation can be adjusted depending on engine speed, but the construction becomes complicated and manufacturing cost increases
Solution Approach 1:
The patent extracts the essential function of variable valve timing from complex CVVT apparatus by using a simplified cam unit with a single cam profile that can be rotated relative to the camshaft. This removes unnecessary components while maintaining the core capability to adjust valve timing based on engine speed through the rotation of the cam unit, thereby reducing construction complexity.
Solution Approach 2:
The cam unit is designed to serve multiple functions: it provides valve timing adjustment, controls valve opening duration, and adapts to different engine speeds through a single integrated structure. The cam unit's rotatable design allows it to perform timing adjustment without requiring separate mechanisms for each function, thus reducing overall system complexity.
2Adaptability or versatility
If general CVVT apparatus is used to change valve timing, then valve timing operation can be adjusted depending on engine speed, but manufacturing cost increases
Solution Approach 1:
The patent removes complex and expensive components from traditional CVVT apparatus, retaining only the essential cam unit structure. This extraction of unnecessary elements significantly reduces manufacturing cost while maintaining the capability to adjust valve timing based on engine speed through the simplified rotatable cam unit design.
Solution Approach 2:
The cam unit is designed as a simple, cost-effective component that can be easily manufactured and replaced if needed. Its straightforward structure with minimal parts reduces manufacturing cost compared to complex CVVT systems, while still achieving the desired valve timing adjustment functionality.
3Ease of manufacture
If continuous variable valve opening duration apparatus is designed with simple construction, then productivity enhances and production cost reduces, but valve operation adaptability may be compromised
Solution Approach 1:
The cam unit is designed to be rotatable relative to the camshaft, introducing dynamic adjustability to the otherwise simple structure. This rotation capability allows the system to adapt valve timing and opening duration to different engine speeds and operating conditions, maintaining adaptability while keeping the overall construction simple and cost-effective.
Solution Approach 2:
The patent changes the parameter of cam unit rotation angle to achieve different valve timing and opening duration characteristics. By varying the rotation angle of the cam unit relative to the camshaft, the system can adapt to different engine operating conditions without requiring complex mechanisms, thus maintaining adaptability with simple construction.
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 reduces the size of the valve train, enhances productivity, and lowers production costs by enabling efficient valve operation based on engine conditions without excessive complexity or expense.
Implementation Method 1
a worm wheel (50) to which an inner screw thread (52) configured for engaging with the guide screw thread (130) is formed therewithin and the worm wheel (50) disposed within the wheel housing (90)
Implementation Method 2
a guide shaft (132) on which a guide screw thread (130) is formed and disposed perpendicular to the camshaft (30)
Data Source
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AI summary
A continuous variable valve duration apparatus may include: a camshaft; a cam unit on which a cam is formed, and the camshaft inserted to the cam; an inner wheel for transmitting rotation of the camshaft to the cam unit; a wheel housing into which the inner wheel is rotatably inserted and movable perpendicular to the camshaft; a guide shaft on which a guide screw thread is formed and disposed perpendicular to the camshaft; a worm wheel formed with an inner screw thread for engaging with the guide screw thread, and the worm wheel disposed within the wheel housing; and a control shaft on which a control worm for engaging with the worm wheel is formed.