ECU Cover Deflection Limiting Structure With Leak Testing Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In sealed engine control units (ECUs) for automotive vehicles, internal pressure buildup at high altitudes causes the cover to deflect outwardly, compromising the sealing arrangement, and existing solutions like vents are not feasible when a sealed ECU is required, with cast covers being expensive and heavy.
Innovation Solution
A support structure is implemented using a stamped metal cover with slots and a fastener that defines an airflow path between the cover and the housing, limiting deflection while allowing for leak testing, and sealant material is used to seal the path after testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealed ECU is used to maintain sealing integrity, then sealing effectiveness is improved, but cover deflection increases under internal pressure at high altitudes
Solution Approach 1:
The cover is segmented by incorporating slots that allow controlled deflection in specific regions while maintaining overall structural integrity. The slots divide the cover into sections that can move independently under pressure, preventing excessive deflection that would compromise the sealing arrangement.
Solution Approach 2:
The cover design incorporates slots with specific dimensions and positions that change the mechanical parameters of the cover structure. These slots allow the cover to accommodate pressure changes by enabling controlled deformation, thereby maintaining sealing effectiveness while managing deflection under internal pressure at high altitudes.
2Shape
If a cast cover is used to limit cover deflection, then cover deflection is reduced, but manufacturing cost and weight increase
Solution Approach 1:
The patent uses a stamped metal cover with integrated slots instead of an expensive cast cover. The stamped design is more cost-effective and easier to manufacture while achieving the same functional outcome of limiting cover deflection through the slot geometry and fastener arrangement.
Solution Approach 2:
By changing the manufacturing method from casting to stamping and incorporating strategic slots, the design achieves comparable deflection control at lower cost. The slots are positioned and dimensioned to provide structural reinforcement where needed while allowing controlled movement elsewhere.
3Ease of manufacture
If a stamped metal cover with slots is used to limit deflection cost-effectively, then manufacturing cost is reduced, but leak testing becomes difficult
Solution Approach 1:
The slots in the cover and circuit board are designed to provide clearances that allow fasteners to pass through while maintaining sealed pathways. These same clearances and pathways are extracted and utilized for leak testing purposes, allowing testing equipment to access the interior space through the existing slot structures without requiring additional openings.
Solution Approach 2:
The slots serve multiple functions: they limit cover deflection structurally, allow fastener passage during assembly, and provide pathways for leak testing. This multi-functionality eliminates the need for separate testing openings and simplifies the overall design while maintaining cost-effectiveness.
4Ease of operation
If slots are provided in cover and circuit board for airflow path, then leak testing is enabled, but sealing complexity increases
Solution Approach 1:
The sealing arrangement is merged with the slot structures and fastener system. The same slots that enable airflow for leak testing are also part of the sealed pathway when properly configured with fasteners and sealant. This integration reduces overall complexity by combining multiple functions into unified structures.
Solution Approach 2:
Sealant material is used as an intermediary substance that seals around the fasteners in the slots, creating a sealed pathway that still allows for leak testing through the slot clearances. The sealant mediates between the need for a tight seal and the need for testing access.
Data Source
AI summary
An engine control unit (ECU) includes a housing; a cover sealingly engaged with the housing so as to define an interior space; a circuit board disposed in the interior space; and a fastener coupling together the circuit board, the housing and the cover, the fastener serving to limit an amount of deflection of the housing relative to the housing. The circuit board and the cover are constructed and arranged to define an airflow path from an outer surface of the cover to the interior space. The airflow path allows for a leak test to be performed on the ECU, wherein upon an affirmative determination that results of the leak test shows no leaks in the ECU, sealant seals the airflow path.