Split Rocker Arm Assembly for Variable Valve Timing
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Solution Overview
Problem
Existing variable valve timing mechanisms in engines have complex structures and high costs due to the need for separate electromagnetic control valves for each cylinder, requiring fast on-off responses and precise timing, which complicates manufacturing and increases costs.
Innovation Solution
A valve rocker arm assembly with a split rocker arm design, incorporating a piston chamber, oil inlet and drain paths, and a control valve to achieve variable valve timing through mechanical means, simplifying the structure and improving reliability by changing the rocker arm length through piston extension and retraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an electro-hydraulic control variable valve mechanism with separate electromagnetic control valves for each cylinder is used, then variable valve timing is achieved, but the structure becomes complicated and cost increases
Solution Approach 1:
The patent merges the control valves into a single common rail system that serves all cylinders, rather than having separate control valves for each cylinder. The common rail receives pressurized oil from a single source and distributes it to multiple rockers through individual control valves, significantly reducing the number of control valves needed while maintaining variable valve timing functionality for all cylinders
Solution Approach 2:
The common rail system serves as a universal oil distribution network that can supply pressurized oil to multiple rockers simultaneously. The single common rail structure performs the function of multiple separate oil supply systems, enabling variable valve timing across all cylinders through a unified control architecture
2Adaptability or versatility
If electro-hydraulic control valves are used for variable valve timing, then valve timing control is achieved, but manufacturing difficulty increases due to strict timing requirements
Solution Approach 1:
The control valves are integrated directly into the rocker arm assemblies, where each control valve is positioned to directly control the oil supply to its corresponding piston chamber. This self-contained arrangement eliminates complex external timing mechanisms and allows the system to self-regulate valve timing based on engine operating conditions, reducing manufacturing complexity
3Measurement precision
If separate electromagnetic control valves are provided for each cylinder, then precise valve timing control is achieved, but cost increases
Solution Approach 1:
The patent combines multiple oil supply functions into a single common rail system that serves all cylinders. Instead of having separate electromagnetic control valves for each cylinder, the system uses a common rail with integrated control valves that distribute pressurized oil to multiple rockers, significantly reducing the number of expensive control valves while maintaining precise valve timing control through centralized oil pressure management
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 simplifies the engine's valve train mechanism, reduces costs by eliminating the need for complex electromagnetic control systems, and enhances operation reliability by mechanically achieving variable valve timing and normal/closed valve modes.
Implementation Method 1
a piston chamber (2), an oil inlet path (4), an oil drain path (3) and a piston (1), wherein the piston (1) is slidably arranged in the piston chamber (2), an extension end of the piston (1) is configured to extend out of the piston chamber (2) and push the first rocker arm (7)
Implementation Method 2
a unidirectional communication device (5), which is provided in the oil inlet path (4) and/or the oil inlet hose (13), and an oil-guiding direction of which is toward the piston chamber (2)
Data Source
Figure 1~2
AI summary
A valve rocker arm assembly, a variable air distribution mechanism, and an engine. The valve rocker arm assembly comprises: an oil inlet hose (13); a rocker arm shaft (11), an oil drain channel (10), an oil return groove (8), and a first oil path (9) being provided in the rocker arm shaft (11), the oil drain channel (10) being communicated with the oil return groove (8) by means of the first oil path (9); a first rocker arm (7) and a second rocker arm (6) rotatably connected onto the rocker arm shaft (11), a piston cavity (2), an oil inlet path (4), an oil drain path (3), and a piston (1) being provided on the second rocker arm (6), the extension end of the piston (1) being used for extending out of the piston cavity (2) and being in push contact with the first rocker arm (7), one end of the oil inlet path (4) and one end of the oil drain path (3) being both communicated with the piston cavity (2), the oil inlet path (4) being connected to the oil inlet hose (13), and connection and disconnection occurring alternately between the oil drain path (3) and the oil return groove (8) along with the swing of the second rocker arm (6); a one-way opening device (5) provided in the oil inlet path (4) and/or the oil inlet hose (13); and a control valve connected to the oil drain channel (10). According to the valve rocker arm assembly, a rocker arm is divided into two sections, and the piston (1) is added onto the rocker arm. A valve can be closed at regular time or early on the basis of the change of the length of the rocker arm.