Valve Timing Controller Reed Valve Segmentation
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Solution Overview
Problem
Existing valve timing controllers face challenges in maintaining accurate control of intake and exhaust valve timing due to variations in working oil flow rates, leading to either increased pressure loss or reduced responsivity.
Innovation Solution
The valve timing controller incorporates a reed valve system with multiple supply passages and reed parts of different lower limit pressures, allowing for secure oil supply at varying flow rates, ensuring quick control of valve timing by connecting and disconnecting passages based on flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the cross-sectional area of the oil passage connected to the reed valve is made smaller, then the valve opening speed of the reed valve is made faster, but a large pressure loss is generated when a large amount of working oil flows through the oil passage, so the responsivity becomes worse
Solution Approach 1:
The single oil passage is segmented into multiple oil passages (first oil passage and second oil passage). The reed valve is also segmented into multiple reed valves (first reed valve and second reed valve). This segmentation allows the oil flow to be distributed across multiple paths, reducing pressure loss while maintaining fast opening speed through the multiple smaller passages working in parallel.
Solution Approach 2:
The reed valves are disposed inside the housing in a nested arrangement within the available space. The multiple reed valves are positioned such that they occupy different spatial locations within the housing structure, allowing compact integration of multiple flow paths without increasing the overall device size.
2Loss of energy
If the cross-sectional area of the oil passage is made larger, then the valve opening speed of the reed valve becomes slow when a small amount of working oil flows through the oil passage, but in this case the reed valve cannot work as the check valve and the responsivity becomes worse
Solution Approach 1:
The oil passage system is segmented into multiple passages with different characteristics. When oil flow is small, the system can utilize passages with larger effective area for faster response. When oil flow is large, multiple passages work in parallel to handle the increased flow with reduced pressure loss. This segmentation allows the system to adapt to different flow conditions.
Solution Approach 2:
The system dynamically adapts its effective oil passage area based on flow conditions. The multiple reed valves open at different pressures, creating a dynamic response where the effective flow area changes with the oil flow rate. This dynamic behavior allows optimal performance across varying operating conditions.
3Device complexity
If a single reed valve is used in the oil passage, then the structure is simple, but the valve cannot maintain accurate control when working oil flow rate varies, leading to either increased pressure loss or reduced responsivity
Solution Approach 1:
The single reed valve is segmented into multiple reed valves with different characteristics. Each reed valve can be optimized for different flow rate ranges, allowing the system to maintain accurate control across a wide range of operating conditions. The segmented structure handles different flow scenarios more reliably than a single valve design.
Solution Approach 2:
The system changes parameters such as reed valve thickness, passage cross-sectional area, and passage length for different oil passages. These parameter variations allow each passage-reed valve combination to be optimized for specific flow rate ranges, improving overall control accuracy and reliability while adapting to varying working oil flow rates.
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 design enables accurate and responsive control of valve timing across varying working oil flow rates, ensuring reliable operation by securely supplying oil and maintaining high switching speed when needed.
Implementation Method 1
Each of the reed parts is formed to extend from an edge of the corresponding hole to cover the corresponding hole so as to open or close an open end of the corresponding first supply passage
Implementation Method 2
The spool slidably moves in the sleeve in an axial direction among an advance position at which the supply port is connected to the advance port, a retard position at which the supply port is connected to the retard port, and a shutoff position at which the supply port is shutoff from the advance port and the retard port
Implementation Method 3
The vane rotor rotates on an advance side or a retard side relative to the second housing based on a pressure of working oil in the advance chamber and the retard chamber
Data Source
AI summary
A valve timing controller includes a reed valve interposed between an end surface of a vane rotor and an end surface of a driven shaft. The reed valve has a fixed part, a first reed part and a second reed part. Each of the first reed part and the second reed part has each lower limit pressure for allowing working oil to flow from a first supply passage to a second supply passage. The lower limit pressure of the first reed part is different from the lower limit pressure of the second reed part.