Sealing Valve for Marine Engine Water Intrusion Prevention
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Solution Overview
Problem
Marine engine assemblies face water intrusion issues when positioned lower than the water level, as the exhaust gas flow ceases when the engine is stopped, increasing the risk of water entering the engine through the exhaust system.
Innovation Solution
A marine engine assembly with a sealing valve in the gas flow pathway that is controlled by an engine management module (EMM) to close when the engine is stopped, preventing gas flow and thus water intrusion, and opens when the engine is operating or starting, using a combination of a throttle valve and sealing valve actuator to manage airflow and prevent water ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the marine engine is positioned lower relative to the watercraft, then more usable room is available in the watercraft, but water intrusion risk increases when the engine is stopped
Solution Approach 1:
The sealing valve is activated in advance before water intrusion can occur. When the engine stops running, the EMM automatically closes the sealing valve to seal the gas flow pathway, creating a protective barrier against water intrusion before the harmful effect can manifest.
Solution Approach 2:
The sealing valve acts as an intermediary element between the gas flow pathway and the potential water intrusion route. By introducing this intermediate component, the patent creates a controlled barrier that can be dynamically opened or closed to prevent water from reaching the combustion chamber while allowing normal exhaust flow during operation.
2Object-affected harmful factors
If the sealing valve is closed to prevent water intrusion, then water protection is improved, but gas flow through the exhaust system is blocked
Solution Approach 1:
The sealing valve transitions from a static component to a dynamic one controlled by the EMM. The valve automatically changes its state based on engine operation status - remaining open during normal operation to allow gas flow, and closing when the engine stops to prevent water intrusion. This dynamic control resolves the contradiction by adapting the valve's function to the operational context.
Solution Approach 2:
The EMM monitors engine operation status and provides feedback control to the sealing valve. When the engine stops running, the EMM detects this condition and automatically activates the sealing valve to close, creating a feedback loop that ensures the valve state always matches the operational requirements for both gas flow and water protection.
3Object-affected harmful factors
If a sealing valve is added to the gas flow pathway, then water intrusion prevention is improved, but device complexity increases
Solution Approach 1:
The sealing valve is integrated into the existing exhaust system architecture, serving multiple functions: it acts as a normal exhaust passage during operation and transforms into a water prevention barrier when the engine stops. The EMM control system, which already exists for engine management, is extended to also control the sealing valve, making the control system multi-functional without adding separate dedicated control hardware.
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
Effectively prevents water intrusion into the combustion chambers by trapping air as a gas spring, resisting water level increases in the exhaust system, even when the engine is stopped, ensuring the engine remains dry and operational.
Implementation Method 1
When the sealing valve is closed, a pressure differential is created between the upstream and downstream sides of the valve. The trapped air acts as a gas spring, using pressure to resist water level increases in the exhaust system and prevent water intrusion into the combustion chamber.
Implementation Method 2
The air trapped between the sealing valve and the water in the exhaust system acts as a gas spring. When water tries to enter the combustion chamber, the compressed air provides elastic resistance, preventing water intrusion even when the engine is stopped.
Data Source
AI summary
A marine engine assembly for mounting to a watercraft is disclosed. The marine engine assembly has an engine unit, an exhaust system fluidly and a propulsion device. The engine unit includes an engine unit housing, an internal combustion engine and an air intake assembly. The air intake assembly, at least one combustion chamber, and the exhaust system together defining at least in part a gas flow pathway. A sealing valve is provided in the gas flow pathway. The sealing valve has an open position permitting flow of gas therethrough. The sealing valve has a closed position preventing flow of gas therethrough for sealing a portion of the gas flow pathway downstream of the sealing valve from a portion of the gas flow pathway upstream of the sealing valve.