Engine Leak Test via Crank Angle Valve Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional leak test methods for engines are time-consuming, especially when filling combustion chambers with large inner volumes, as they require rotating camshafts to open and close valves, prolonging the time needed to detect leaks.
Innovation Solution
The method involves setting a specific crank angle where intake or exhaust valves of larger combustion chambers are open, allowing fluid injection through intake and exhaust ports, and measuring pressure post-injection, reducing the need for subsequent rotation and speeding up the leak test process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the camshafts are rotated to open and close the intake or exhaust valve of each of all the cylinders to fill the combustion chambers with fluid, then the leak test can be performed, but it takes a long time before the leak test is started
Solution Approach 1:
The patent applies preliminary action by pre-positioning the crankshaft at a specific phase before fluid injection, where the intake or exhaust valve of each cylinder with a large combustion chamber is already in the open state. This eliminates the need to rotate the camshafts after fluid supply begins, allowing large combustion chambers to be filled promptly while reducing overall test time.
2Quantity of substance
If the camshafts are rotated to open the intake or exhaust valve of each of all the cylinders, then the fluid can be supplied to the combustion chambers, but it takes a lot of time to fill the combustion chambers having a large inner volume
Solution Approach 1:
The patent applies local quality by differentiating the valve states based on combustion chamber characteristics. At the specific crankshaft phase, only the intake or exhaust valve of cylinders with large combustion chambers (those exceeding the average inner volume) are kept open, while other valves may remain closed. This targeted approach prioritizes fluid supply to large chambers without unnecessarily actuating all valves, reducing time while ensuring adequate filling.
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 approach significantly reduces the time required for the leak test while ensuring accurate measurement by keeping larger chambers open for fluid supply and smaller ones closed, minimizing measurement interference, and efficiently filling all chambers with fluid.
Implementation Method 1
injecting, when the crankshaft is at the set crank angle, a fluid for a leak test through intake ports and exhaust ports in which the intake valves and the exhaust valves are respectively disposed
Implementation Method 2
measuring a pressure in the engine after injection of the fluid is completed
Data Source
AI summary
In a leak test method, a crank angle is set to a specific phase. When a crankshaft is positioned in the specific phase, an intake or exhaust valve of each cylinder including a combustion chamber having an inner volume that has become larger than an average value of inner volumes of combustion chambers of all the cylinders is open. When the crankshaft is at the set crank angle, a fluid for leak test is injected through intake and exhaust ports where the intake and the exhaust valves are disposed and that communicate with the combustion chambers, and through an engine opening other than the intake and the exhaust ports, with an opening of the engine other than the intake and exhaust ports and the engine opening to which the fluid is supplied in the leak test sealed. After fluid injection is completed, a pressure in the engine is measured.