Variable Valve Apparatus Load Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable valve apparatuses for internal combustion engines face excessive load on the oscillating fulcrum and control shaft at high valve lift and high speed operations, leading to deformation and inconsistencies in valve characteristics across cylinders, causing engine vibration, output degradation, and increased fuel consumption.
Innovation Solution
The arrangement of the oscillating fulcrum and rotation center of the control shaft between the maximum load directions during valve opening and closing operations alternates the load direction, preventing excessive torque and deformation, and allowing for a simpler and more compact structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a transmission arm is used to vary valve characteristics continuously, then valve opening period and valve lift amount can be varied continuously, but excessive load works on the oscillating fulcrum at high valve lift and high speed operation
Solution Approach 1:
The invention changes the spatial arrangement from a conventional single-plane configuration to a three-dimensional configuration where the oscillating fulcrum is positioned above the camshaft axis. This dimensional change allows the load vector to be distributed differently, reducing the excessive load on the oscillating fulcrum while maintaining continuous valve characteristic variability through the transmission arm mechanism
2Strength
If a strong oscillating fulcrum and highly rigid control shaft are used to withstand excessive load, then deformation is prevented, but the structure becomes complicated and larger
Solution Approach 1:
By repositioning the oscillating fulcrum in the vertical dimension above the camshaft axis, the invention reduces the load on the oscillating fulcrum to normal levels. This eliminates the need for overly strong, complex, and large-scale fulcrum and control shaft structures, achieving the required strength with a simpler and more compact design
3Strength
If a large capacity actuator is used to overcome excessive torque, then the control shaft deformation is prevented, but the actuator size and cost increase
Solution Approach 1:
The vertical repositioning of the oscillating fulcrum reduces the excessive torque to normal levels by changing the load distribution geometry. This allows the use of a smaller, lighter actuator with reduced capacity while still preventing control shaft deformation and maintaining the required torque resistance
Data Source
AI summary
A variable valve apparatus is employed a configuration in which, at a high valve lift and high speed operation of an internal combustion engine, an oscillating fulcrum of a transmission arm and a rotation center of a control shaft are arranged between a direction of a component rotating a control shaft of a maximum load which occurs in the oscillating fulcrum of the transmission arm when an oscillating cam oscillates in a valve opening direction and a direction of a component rotating a control shaft of a maximum load opposite thereto which occurs when the oscillating cam oscillates in a valve closing direction.