Variable Valve Duration Apparatus Reducing Engine Noise
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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 simplified design, featuring a control shaft, worm wheel, and guide brackets that allow for adjustable valve opening duration, reduced size, and easy assembly, incorporating a wheel elastic portion to mitigate production errors and enhance noise and vibration reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a continuously variable valve timing (CVVT) apparatus is used to change valve timing, then valve timing optimization is achieved, but the valve opening duration remains fixed and noise and vibration reduction is limited
Solution Approach 1:
The patent implements continuous variability in both valve timing and valve opening duration. The valve duration control mechanism dynamically adjusts the opening duration by varying the rotational speed ratio between the camshaft and cam unit, allowing the system to adapt to different engine operating conditions and effectively reduce noise and vibration across various regimes.
Solution Approach 2:
The patent changes the key parameter of valve opening duration by controlling the rotational speed ratio between the camshaft and cam unit. By varying this speed ratio continuously, the system can optimize both valve timing and opening duration, achieving better noise and vibration reduction compared to fixed-duration systems.
2Measurement precision
If a complex construction is used to achieve continuous variable valve duration, then precise control is achieved, but production costs increase and productivity decreases
Solution Approach 1:
The patent merges the valve timing control and valve duration control functions into a single integrated mechanism. The cam unit simultaneously controls both the timing and duration of valve opening by its rotational position and speed ratio relative to the camshaft, eliminating the need for separate control systems and reducing construction complexity.
Solution Approach 2:
The cam unit serves multiple functions: it controls valve timing, valve opening duration, and adapts to different engine operating conditions all through a single mechanism. This multi-functionality reduces the number of components needed and simplifies the overall construction while maintaining precise control.
3Measurement precision
If multiple separate mechanisms are used for valve timing and duration control, then precise control is achieved, but device complexity increases
Solution Approach 1:
The patent combines valve timing control and valve duration control into a single cam unit mechanism. The rotational position of the cam unit controls timing, while the rotational speed ratio controls duration, allowing both functions to be achieved through one integrated component rather than multiple separate mechanisms.
Solution Approach 2:
The cam unit is designed as a universal component that performs multiple control functions simultaneously - adjusting valve timing and valve opening duration based on engine operating conditions. This multi-functional design reduces device complexity while maintaining precise control capabilities.
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 according to engine conditions, reducing noise and vibration, enhancing productivity by simplifying construction and reducing production costs, while being easily applicable to existing engines.
Implementation Method 1
a worm wheel (50) mounted on the first guide bracket and the second guide bracket (120, 130) respectively to engage the wheel housing (90)
Implementation Method 2
incorporating a wheel elastic portion to mitigate production errors and enhance noise and vibration reduction
Data Source
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AI summary
A continuously variable valve duration apparatus may include a camshaft, a cam unit on which a cam is formed, wherein the camshaft is inserted into the cam unit, first and second guide brackets into which the camshaft is inserted, a wheel housing movably mounted to the first guide bracket and the second guide bracket, respectively, an internal wheel rotatably provided on each wheel housing and transmitting rotation of the camshaft to the cam unit, a worm wheel mounted on the first guide bracket and the second guide bracket, respectively to engage the wheel housing, a control shaft which is rotatably mounted on the first guide bracket and the second guide bracket, and engages with the each worm wheel to move the position of the wheel housing according to its rotation, and a connecting member that connects the first guide bracket and the second guide bracket.