Six-Cycle Engine Valve Timing to Reduce Pumping Loss
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Solution Overview
Problem
Conventional six-cycle internal combustion engines suffer from pumping loss due to energy losses in intake and exhaust strokes, leading to inferior engine output compared to four-cycle engines.
Innovation Solution
The engine operates by combining four-cycle and two-cycle strokes, with specific valve opening and closing sequences and fuel ignition stages, including a first-stage and second-stage ignition with different fuels, and a valve opening/closing mechanism that adjusts with rotation speed, utilizing an external supercharger and EGR device to optimize intake and exhaust processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If six-cycle operation is implemented by adding intake and exhaust strokes after four-cycle strokes, then the engine can operate with six strokes, but pumping loss increases and engine output deteriorates
Solution Approach 1:
The engine implements periodic action by alternating between four-cycle operation (at low load) and six-cycle operation (at high load). The control unit switches between these two operational modes based on load conditions, allowing the engine to achieve high output when needed while maintaining efficiency at lower loads, thereby resolving the contradiction between engine output and pumping loss.
Solution Approach 2:
The invention changes operational parameters by adjusting valve timing and injection timing based on the operational mode. During six-cycle operation, the intake valve opens earlier and closes later, and the injection timing is advanced, which optimizes combustion efficiency and reduces pumping loss while maintaining high output. This dynamic parameter adjustment resolves the contradiction between productivity and energy loss.
2Power
If six-cycle operation is implemented, then the engine can increase power output, but fuel consumption increases due to additional strokes
Solution Approach 1:
The invention applies dynamics by making the engine operational characteristics variable rather than fixed. The control unit dynamically switches between four-cycle and six-cycle modes based on load requirements, and adjusts valve timing and injection timing in real-time. This dynamic adaptation allows the engine to achieve high power when needed while minimizing fuel consumption during normal operation, resolving the contradiction between power and fuel consumption.
Solution Approach 2:
The invention implements preliminary action through early injection timing and early intake valve opening in six-cycle mode. By preparing the air-fuel mixture earlier and initiating combustion at optimal timing, the engine achieves more efficient energy utilization during high-power operation, reducing the fuel consumption penalty associated with increased power output.
3Loss of energy
If early intake valve closing is implemented to reduce pumping loss, then pumping loss decreases, but intake charge volume is reduced
Solution Approach 1:
The invention uses periodic action by implementing different valve timing strategies for different operational modes. In four-cycle mode, conventional valve timing is used to ensure sufficient intake charge. In six-cycle mode, early intake valve closing is applied to reduce pumping loss. This periodic switching resolves the contradiction between reducing pumping loss and maintaining adequate intake charge volume.
Solution Approach 2:
The invention changes the intake valve timing parameter dynamically based on operational mode. During six-cycle operation, the intake valve closes earlier to reduce pumping loss, while during four-cycle operation, the valve timing is adjusted to ensure adequate charge volume. This parameter change strategy resolves the contradiction between energy loss reduction and substance quantity maintenance.
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 configuration reduces pumping loss, increases output, and improves thermal efficiency, making it suitable for gasoline and diesel engines, with enhanced fuel efficiency and reduced friction and emissions.
Implementation Method 1
an external supercharger and EGR device are provided
Implementation Method 2
an external supercharger and EGR device are provided between the exhaust valve and the intake valve
Implementation Method 3
a first-stage ignition stroke in which first-stage ignition is performed when the piston reaches a top dead center
Implementation Method 4
a common rail diesel injection device for supplying common rail diesel to injection nozzles
Implementation Method 5
a first-stage compression stroke in which compression is performed by moving up the piston
Data Source
Figure 1~1(C)
Figure 2~2(F)
Figure 3~3(H)
AI summary
[Object] To reduce pumping loss in a six-cycle internal combustion engine and increase the output. [Solution Means] Exhaust is performed by opening an exhaust valve 30 when a piston 14 moves down after intake, compression, first-stage ignition, and combustion, and an intake valve 20 is also opened before the piston 14 reaches a bottom dead center, and scavenging and intake are performed until the piston 14 moves up again. Then, by closing both of the valves 20 and 30 and moving up the piston 14, compression is performed, and fuel is injected from a fuel nozzle 40. Then, when the piston 14 reaches a top dead center (or the vicinity of the top dead center), second-stage ignition is performed by an ignition plug 12. The piston 14 moves down in response to combustion, and the exhaust valve 30 is opened for exhaust. By combining an intake stroke → a compression stroke → a combustion stroke → an exhaust stroke in a four-cycle internal combustion engine with an intake and compression stroke → a combustion and exhaust stroke in a two-cycle internal combustion engine, pumping loss is reduced, the output is increased, and thermal efficiency is improved.