Variable Valve Lift Mechanism for Engine Speed Adaptation
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Solution Overview
Problem
Conventional valve lift apparatuses have a fixed valve lift amount due to fixed cam shapes, making them inadequate for adjusting gas introduction or exhaust at varying engine speeds, as they are either insufficient for low speeds or excessive for high speeds.
Innovation Solution
A continuous variable valve lift apparatus with a cam carrier, input and control shafts, links, and a control motor with a worm gear, allowing for adjustable valve lift through a mirror design that enhances assembly characteristics and reduces production costs by using wall portions to prevent separation and simplify assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed cam shape is used in a conventional valve lift apparatus, then the structure is simple and easy to manufacture, but the valve lift amount cannot be adjusted for different engine speeds
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed cam shape into a variable cam mechanism. The control shaft can rotate to different angles (0°, 45°, 90°, 135°) to change the cam profile, allowing the valve lift amount to be dynamically adjusted according to engine operating conditions. This enables the system to adapt between different engine speeds while maintaining a relatively compact structure.
2Speed
If the valve lift apparatus is designed for low driving speeds, then the structure is simpler, but the valve open time and amount are insufficient for high speeds
Solution Approach 1:
The patent implements dynamics by providing a control shaft that can be positioned at multiple angles (0°, 45°, 90°, 135°) to change the cam profile. This allows the valve lift apparatus to be dynamically adjusted for different engine speeds, ensuring sufficient valve open time and amount at high speeds while maintaining simplicity at low speeds.
Solution Approach 2:
The patent applies parameter changes by varying the cam profile parameters through different control shaft angles. Each angle (0°, 45°, 90°, 135°) corresponds to a different cam profile with specific lift characteristics, allowing the system to optimize valve operation parameters for different engine operating conditions.
3Productivity
If the valve lift apparatus is designed for high speeds, then the valve open time and amount are sufficient, but the structure becomes more complex
Solution Approach 1:
The patent applies dynamics by providing a control shaft that can be positioned at multiple angles (0°, 45°, 90°, 135°) to change the cam profile. This allows the valve lift apparatus to be dynamically adjusted for different engine speeds, ensuring sufficient valve open time and amount at high speeds while maintaining simplicity at low speeds.
4Adaptability or versatility
If a conventional valve lift apparatus is used, then manufacturing is straightforward, but it cannot adjust gas introduction or exhaust amounts at varying engine speeds
Solution Approach 1:
The patent applies the dynamics principle by transforming the fixed cam shape into a variable cam mechanism. The control shaft can rotate to different angles (0°, 45°, 90°, 135°) to change the cam profile, allowing the valve lift amount to be dynamically adjusted according to engine operating conditions. This enables the system to adapt between different engine speeds while maintaining a relatively compact structure.
Solution Approach 2:
The patent applies parameter changes by varying the cam profile parameters through different control shaft angles. Each angle (0°, 45°, 90°, 135°) corresponds to a different cam profile with specific lift characteristics, allowing the system to optimize valve operation parameters for different engine operating conditions.
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
Enables continuous adjustment of valve lift, improving engine operation by allowing for various lift operation ranges, reducing production and maintenance costs, and enhancing engine control through a mirror design that supports mass production without high costs.
Implementation Method 1
a control portion coupled to the control shaft and controlling rotation angle thereof. The control portion may include a control motor and a worm gear, wherein the worm gear is coupled to an end of the control shaft.
Implementation Method 2
a control link, one end of which is rotatably coupled to the input link and the other end of which is eccentrically coupled to the control shaft
Data Source
AI summary
A variable valve lift apparatus includes an input cam disposed to a input shaft, a valve opening unit, a control shaft parallel to the input shaft, an input link rotatably coupled to the control shaft and contacting the input cam, a control link connected with the input link and eccentrically connected to the control shaft, a connecting link connected with the control link, and a lift arm that is rotatably coupled to the control shaft, is connected with the connecting link, and drives the valve opening unit.