Ignition Coil Boot Venting to Reduce Plug Hole Water Entry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face issues with water entry into the plug hole, which can hinder proper combustion, especially when exposed to rain or cleaning water, and existing ignition coils do not effectively prevent water ingress.
Innovation Solution
The ignition coil features a boot with a tubular shape, including a main portion, a distal end portion, a seal portion with a larger outer diameter, and an air passage with a first opening on the outer circumferential surface of the main portion, which reduces water entry by retaining water on the seal portion and preventing it from entering the air passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If an air vent is provided to discharge air from the plug hole, then air pressure inside the plug hole is reduced, but water can enter through the air vent and hinder combustion
Solution Approach 1:
The air passage is provided with a specific opening direction (upward or outward) and positioned above the seal portion, creating different functional zones: the seal portion blocks water while the directed air opening allows air discharge. This local differentiation of quality and function resolves the contradiction between air venting and water protection.
Solution Approach 2:
The seal portion acts as an intermediary element between the external environment and the plug hole interior. It selectively blocks water while allowing the air passage to function, mediating between the need for air discharge and the need to prevent water entry.
2Volume of moving object
If the boot is made compact and bent-shaped to meet space requirements, then the engine and peripheral devices can be arranged more compactly, but water retention and entry risk increase
Solution Approach 1:
The boot is designed with different sections having different diameters: a smaller main portion and a larger seal portion. This local variation in geometry serves dual purposes: maintaining compact overall dimensions while creating a water-retaining seal portion that prevents water from reaching the air passage opening.
Data Source
AI summary
A boot of an ignition coil 2 includes: a main portion 18; a distal end portion 22; a seal portion 24 located between the main portion 18 and the distal end portion 22 and having a larger outer diameter than the main portion 18; and an air passage 28. When the ignition coil 2 is mounted on an internal combustion engine 20, the main portion 18 is exposed to an external environment, the distal end portion 22 is inserted in a plug hole 34 of the internal combustion engine 20, the seal portion 24 separates the external environment and the plug hole 34 from each other, and the air passage 28 connects the external environment and the plug hole 34 to each other. A first opening 44 of the air passage 28 is located in an outer circumferential surface of the main portion 18.