Hydraulic Lost-Motion Valve Control for Low-Vibration Engine Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large diesel engines experience excessive vibrations during shutdown due to residual cylinder compression pressures, which can cause wear on starter components and are often addressed separately by decompression and cylinder deactivation systems, increasing cost and complexity.
Innovation Solution
A method using hydraulically controlled lost motion components with a pressure maintenance system to maintain hydraulic pressure during engine shutdown, ensuring cylinder deactivation and decompression without separate hardware for both functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If separate decompression and cylinder deactivation systems are deployed independently, then engine shutdown vibrations are minimized, but device complexity and cost increase
Solution Approach 1:
The patent combines decompression and cylinder deactivation functions into a single integrated system. The lost motion component serves dual purposes: it acts as a decompression device by allowing exhaust valve operation while blocking intake valve operation during shutdown, and simultaneously functions as a cylinder deactivation mechanism. This merging eliminates the need for separate hardware systems while achieving both vibration reduction and decompression objectives.
Solution Approach 2:
The lost motion component is designed with multi-functionality to perform both decompression and cylinder deactivation roles. By controlling the intake valve through the lost motion mechanism while allowing exhaust valve operation, the system achieves decompression (preventing high compression pressures) and cylinder deactivation (preventing power generation) simultaneously, making the component universal in its application.
2Adaptability or versatility
If hydraulically controlled lost motion component is used for cylinder deactivation, then valve actuation motions are absorbed, but hydraulic fluid pressure decrease during shutdown can cause locking mechanism to re-lock
Solution Approach 1:
The system dynamically adapts the state of the lost motion component during shutdown. The hydraulic control allows the component to transition from its normal locked state (transmitting valve motions) to an unlocked state (absorbing valve motions) during shutdown, and then return to locked state after shutdown. This dynamic state change enables the system to accommodate the temporary loss of hydraulic pressure while maintaining reliable operation throughout the shutdown sequence.
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
Reduces engine vibrations and wear by maintaining cylinder deactivation and decompression during shutdown, simplifying engine design and reducing hardware requirements.
Implementation Method 1
when pressurized hydraulic fluid is applied to the locking mechanism as a control input, the locking mechanism assumes an unlocked state
Implementation Method 2
Decompression systems cause intake and/or exhaust valves to be maintained in an open state in unfueled cylinders during the engine shutdown process, thereby preventing the generation of high cylinder pressures
Data Source
AI summary
Control of engine shutdown of an internal combustion engine comprising a plurality of cylinders and, for each of the plurality of cylinders, a hydraulically controlled lost motion component operatively connected to an engine valve corresponding to the cylinder, is achieved when an engine controller determines that shutdown of the internal combustion engine has been requested. Responsive to the request for shutdown, the engine controller initiates or continues cylinder deactivation operation for each of at least one cylinder of the plurality of cylinders. The initiation or continuation of the cylinder deactivation operation for each of the at least one cylinder comprises, for an input to the hydraulically controlled lost motion component for each of at least one engine valve corresponding to the cylinder, operating the input to provide the cylinder deactivation operation for a duration at least long enough to complete shutdown of the internal combustion engine.