Battery Case Insert-Nut Sealing for Waterproof Pinhole Blocking

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Solution Overview

Problem

Existing battery cases suffer from water leakage issues, compromising their waterproof performance, particularly when high waterproof grades are required.

Innovation Solution

A battery case design featuring an insert nut supported by a pin formed in the mold during injection molding, with a pinhole adjacent to the nut, which is sealed using a heating member to form a sealing protrusion, enhancing waterproofing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an insert nut is provided in the battery case for structural assembly, then the ease of manufacture is improved, but a pinhole is formed adjacent to the insert nut which compromises waterproof performance

Engineering Contradiction:

Improveease of manufactureVSAvoidwaterproof performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A protrusion is formed in advance at the location where the pinhole will be created during insert molding. This protrusion serves as a pre-prepared sealing structure that will later be used to block the pinhole, ensuring waterproof performance while maintaining the manufacturing benefits of using an insert nut.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sealing structure is localized specifically at the pinhole location adjacent to the insert nut. By forming a protrusion only where needed and selectively blocking the pinhole, the solution provides waterproof performance exactly where required without affecting other areas of the battery case or compromising the overall manufacturing process.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If a pin is formed in the mold to support the insert nut during injection molding, then the manufacturing precision is improved, but a pinhole is created which harms waterproof performance

Engineering Contradiction:

Improvemanufacturing precisionVSAvoidwater leakage

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The pinhole, which is initially harmful as it causes water leakage, is converted into a beneficial feature by forming a protrusion at that exact location. The protrusion is then blocked to create a sealing structure, transforming the harmful pinhole into a positive waterproofing element that actually enhances the battery case's protective function.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The pinhole is effectively blocked, preventing water leakage and improving the case's waterproof performance, ensuring reliability in demanding conditions.

Implementation Method 1

a heating member heats the protrusion to seal the pinhole

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentEP4322300B1Battery case, battery module, battery pack, and vehicle including the battery case, and method of manufacturing the battery case

Publication Date: 2025.09.10 LG ENERGY SOLUTION LTD

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AI summary

Provided are a battery case, a battery module, a battery pack, and a vehicle including the battery case, and a method of manufacturing the battery case. A battery case according to an embodiment includes a lower case in which a plurality of battery cells are accommodated, and an upper case coupled to the lower case, wherein an insert nut is provided in at least one of the upper case and the lower case, a pinhole is formed at a position adjacent to the insert nut of the at least one of the upper case and the lower case, and the pinhole is blocked.