Continuous Variable Valve Duration Apparatus for Engine Noise Reduction
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Solution Overview
Problem
Existing engine valve systems struggle to optimize valve operation based on engine rotation speed, leading to inefficiencies, noise, and vibration, particularly due to manufacturing tolerances and fixed valve opening durations.
Innovation Solution
A continuous variable valve duration apparatus featuring a camshaft, guide shaft, worm wheel, and elastic components, allowing for adjustable valve opening duration and reduced noise and vibration through a double torsion spring mechanism, enabling optimal valve operation based on engine conditions without extensive modification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed valve opening duration system is used, then the structure is simple, but the valve operation cannot be optimized based on engine rotation speed
Solution Approach 1:
The patent implements a continuous variable valve duration system where the wheel housing can move axially along the camshaft, changing the effective cam profile and valve opening duration dynamically. The worm wheel mechanism allows continuous adjustment of the wheel housing position, enabling the valve duration to vary continuously with engine operating conditions rather than being fixed.
2Object-affected harmful factors
If manufacturing tolerances are not compensated, then the structure is simple, but noise and vibration increase
Solution Approach 1:
The patent introduces a spring mechanism that applies pre-compression force to the wheel housing, creating a cushioning effect that compensates for manufacturing tolerances and clearance variations in the mechanical components. This spring cushioning reduces impact and vibration caused by tolerance accumulation while maintaining reliable mechanical engagement.
3Productivity
If the valve train size is reduced, then productivity increases, but the mechanism becomes more compact and complex
Solution Approach 1:
The patent combines multiple functions into integrated components: the wheel housing serves both as a structural support and as the moving element that changes valve duration; the worm wheel integrates both the actuation mechanism and the position adjustment function; the spring mechanism provides both force application and tolerance compensation. This functional integration reduces the overall number of separate components and compactness the valve train.
4Adaptability or versatility
If continuous variable valve duration is implemented, then valve operation optimizes based on engine conditions, but the mechanism complexity increases
Solution Approach 1:
The patent uses the wheel housing as an intermediary element between the camshaft and the valve train. By moving the wheel housing axially, the effective cam profile changes, providing continuous variable valve duration control. The worm wheel acts as an intermediary mechanism to convert rotational motion into the axial displacement of the wheel housing, enabling smooth and continuous adjustment without complex control systems.
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 based on engine operation conditions, reduces noise and vibration, and minimizes the size of the valve train, enhancing productivity and reducing production costs by applying a wheel elastic portion to manage tolerances.
Implementation Method 1
an wheel elastic portion providing elastic force to the worm wheel to bring the worm wheel into close contact with the guide shaft and the control shaft
Implementation Method 2
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
Data Source
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AI summary
A continuous variable valve duration apparatus may include a camshaft, a cam unit including a cam, and the camshaft inserted into the cam, a guide shaft on which a guide screw thread is formed and disposed perpendicular to the camshaft, a guide bracket on which the guide shaft is mounted, an inner wheel configured to transmit 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, and the wheel housing disposed within the guide bracket, a worm wheel to which an inner screw thread configured to engage with the guide screw thread is formed therewithin, and to which an outer screw thread is formed thereon, and the worm wheel disposed within the wheel housing, a control shaft on which a control worm configured to engage with the outer screw thread is formed.