Battery Housing Lid Bolt Assembly for Airtight Impact Resistance

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Solution Overview

Problem

Current bolt fixation methods for vehicle battery lids, such as welding and adhesive attachment, fail to ensure optimal airtightness and can cause deformations or detachment under impact, leading to potential installation errors and airtightness issues.

Innovation Solution

A bolt design with a grooved intermediate portion and a widened head, using a water-based or toluene-based microencapsulated adhesive for secure yet controlled attachment to the lid, ensuring airtightness and resistance to impacts without deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If welding is used to fix the bolt to the lid, then the attachment strength is improved, but the airtightness deteriorates due to perforations and deformations

Engineering Contradiction:
Improveattachment strengthVSAvoidairtightness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent replaces the welding process with a mechanical press-fit system. The bolt features an intermediate portion with external threading that engages with internal threading in the lid, eliminating the need for welding. This mechanical engagement provides both attachment strength and maintains airtightness by avoiding thermal deformation and perforations associated with welding.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The bolt is segmented into distinct functional portions: a head for tool engagement, an intermediate portion with external threading for mechanical engagement, and a body for structural support. This segmentation allows each portion to perform its specific function optimally - the intermediate portion provides secure mechanical attachment while the design maintains airtightness without welding.

Inventive Principle:
Principle #1Segmentation

2Reliability

If adhesive is used to fix the bolt to the lid, then the airtightness is improved, but the attachment strength deteriorates under impact

Engineering Contradiction:
ImproveairtightnessVSAvoidattachment strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent merges two fixation mechanisms: press-fit mechanical engagement and adhesive bonding. The intermediate portion of the bolt provides mechanical press-fit attachment through external threading engagement, while adhesive is applied to seal and reinforce the connection. This combination achieves both high attachment strength under impact and maintained airtightness.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the bolt head is placed on the upper face of the lid, then the assembly is simplified, but the airtightness deteriorates due to leakage risk

Engineering Contradiction:
Improveassembly simplicityVSAvoidairtightness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent inverts the conventional bolt orientation by placing the threaded intermediate portion on the upper face of the lid instead of the head. The bolt is inserted from below, with the head remaining on the lower face and the threaded portion engaging with internal threading in the lid from the upper face. This inversion maintains airtightness while simplifying the assembly process.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4283141B1Vehicle battery housing lid systems
Publication Date: 2025.01.15 SERVICES FRANCE AGENCE SFA
  • EP4283141B1 patent drawingFigure 1~2
  • EP4283141B1 patent drawingFigure 3~5
  • EP4283141B1 patent drawingFigure 6~8

AI summary

Bolt (15) for vehicle battery housing lids (1) including an elongated body (16) extending in a longitudinal direction and a head (17) arranged at a lower end of the body (16), further having an intermediate portion (18) arranged in the lower part of the body (16), where the lower part of the intermediate portion (18) contacts the upper part of the head (17) of the bolt, and where the outer lateral surface of the intermediate portion (18) is provided with grooves in its outer lateral surface and is configured to contact a part of the inner surface of the passage through the lid (1).