Variable Valve Duration Cam Mechanism for Engine Adaptability
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Solution Overview
Problem
Existing engine technologies face challenges in optimizing valve operation based on engine speed, particularly in varying valve opening duration efficiently, which affects engine performance and efficiency.
Innovation Solution
A variable valve duration system that includes a camshaft, a first cam with a variable phase angle, a slider housing, a solenoid valve, and a position controller to adjust the relative position of the slider housing, allowing for hydraulic pressure control to change the valve opening duration based on engine operation conditions.
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 device complexity increases
Solution Approach 1:
The patent implements dynamic adjustability of the valve opening duration by allowing the camshaft to rotate relative to the cylinder head through a variable duration mechanism. This enables the system to adapt valve duration to different operating conditions, transforming a static system into a dynamic one that can optimize both timing and duration independently.
Solution Approach 2:
The patent separates the control of valve timing and valve duration into independent mechanisms. The CVVT apparatus controls timing while the variable duration mechanism controls duration, allowing each function to be optimized independently without interfering with the other, thus resolving the contradiction between adaptability and complexity.
2Adaptability or versatility
If multiple components are added to achieve variable valve duration, then valve operation adaptability is improved, but engine weight and driving resistance increase
Solution Approach 1:
The patent integrates the variable duration mechanism within the existing camshaft assembly, merging multiple functions into a unified structure. The camshaft itself serves as both the timing control element and the duration control element through its ability to rotate relative to the cylinder head, reducing the need for separate heavy components.
Solution Approach 2:
The camshaft is designed to perform multiple functions: it provides timing control through its rotation and simultaneously controls valve duration through its relative rotation with the cylinder head. This multi-functionality reduces the number of separate components needed, thereby reducing overall engine weight while maintaining adaptability.
3Productivity
If a complex valve control system is implemented, then engine performance is improved, but manufacturing cost and production complexity increase
Solution Approach 1:
The patent employs a dynamic variable duration mechanism that allows the camshaft to rotate relative to the cylinder head, enabling the system to adapt to different performance requirements. This dynamic capability is achieved through a mechanically straightforward implementation that avoids excessive complexity in manufacturing.
4Device complexity
If valve duration is kept fixed for simplicity, then device complexity is reduced, but engine efficiency across different operating conditions deteriorates
Solution Approach 1:
The patent implements a dynamic variable duration mechanism that allows the camshaft to rotate relative to the cylinder head, enabling the system to adapt valve duration to different operating conditions. This dynamic capability significantly improves engine efficiency across various speeds and loads while maintaining relatively simple construction through mechanical implementation.
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
This system reduces engine weight and driving resistance, enhances productivity, and lowers production costs by allowing for a simple and compact design that adapts valve operation to engine conditions without excessive modification.
Implementation Method 1
a solenoid valve configured to selectively supply hydraulic pressure, and a position controller configured to selectively change a position of the slider housing according to the selective supplying of the hydraulic pressure from the solenoid valve
Data Source
AI summary
A variable valve duration system may include a camshaft, a first cam portion including a first cam, into which the camshaft is inserted and of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing into which the inner bracket is rotatably inserted, a first rocker arm having a first end contacting the first cam and a second end connected to a first valve, a rocker shaft to which the first rocker arm is rotatably connected, a solenoid valve to selectively supply hydraulic pressure, and a position controller to selectively change a position of the slider housing according to the selective supplying of the hydraulic pressure from the solenoid valve.