Variable Valve Lift Apparatus Single Cam Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional valve lift apparatuses have a fixed valve lift, which limits their ability to optimize engine performance across various driving ranges, leading to inefficiencies in gas introduction and exhaust, and often result in increased driving mass and reduced structural rigidity, making them unsuitable for high-speed driving.
Innovation Solution
A single cam type variable valve lift apparatus with a simple structure, low driving weight, and high structural rigidity, utilizing a swing arm scheme with a driving plunger, elastic members, and a hydraulic pressure supply system to adjust valve lift based on engine operational states, allowing for selective fixation and hydraulic pressure control to optimize valve operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional high-low cam separation type variable valve lift apparatus is used, then operational stability and design freedom are improved, but driving mass increases and continuous variable valve lift capability is reduced
Solution Approach 1:
The patent merges the low cam and high cam into a single integrated cam structure with different cam profiles. This single cam can provide both low lift and high lift characteristics by utilizing different portions of the cam profile, thereby reducing the driving mass compared to separate cam systems while maintaining operational stability through the unified structure.
Solution Approach 2:
The single cam structure is designed to perform multiple functions - providing both low lift operation and high lift operation through different cam profiles on the same cam. This multi-functional design eliminates the need for separate cam systems, reducing overall mass while maintaining the ability to provide stable variable valve lift control.
2Adaptability or versatility
If a conventional swing arm type 2-stable variable valve lift is used, then variable valve lift capability is achieved, but driving mass increases and structural rigidity deteriorates
Solution Approach 1:
The patent combines the inner body and outer body into a single integrated swing arm structure. This unified structure eliminates the mass increase associated with dual-body systems while maintaining the variable valve lift capability through the swing arm's rotational motion. The single structure also improves structural rigidity by eliminating the interfaces and connections between separate bodies.
3Device complexity
If a fixed valve lift apparatus is used, then structural simplicity is maintained, but engine performance optimization across various driving ranges is limited
Solution Approach 1:
The patent implements a dynamic valve lift system where the valve lift amount can be varied based on engine operating conditions. The swing arm mechanism allows the valve lift to change dynamically as the cam rotates, enabling the system to adapt to different driving ranges and optimize engine performance while maintaining relatively simple structural 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
The solution enables adjustable valve lift, improving engine efficiency, reducing fuel consumption, and allowing the apparatus to function as a Cylinder De-activation (CDA) system, while maintaining a lightweight and rigid design, thus enhancing engine output and operational flexibility.
Implementation Method 1
a driving plunger portion elastic member disposed in the driving plunger groove for biasing the driving plunger
Implementation Method 2
a stopper pin portion elastic member disposed in the stopper pin groove for biasing the stopper pin into a stopper pin coupling groove formed on the driving plunger
Implementation Method 3
a hydraulic pressure supply unit for selectively supplying hydraulic pressure to the locking unit
Data Source
AI summary
A variable valve lift apparatus is provided comprising: an arm; a valve and valve springs connected to a first end of the arm for controlling an air intake and an air exhaust; a driving plunger disposed in a driving plunger groove formed on a second end of the arm which is opposite to the first end; a driving plunger portion elastic member disposed in the driving plunger groove for biasing the driving plunger; a support coupled to a cylinder head for supporting the driving plunger; a locking unit for selectively fixing the driving plunger; and a hydraulic pressure supply unit for selectively supplying hydraulic pressure to the locking unit.