Battery Top Cover Pole Assembly With Variable-Section Pressing Hole

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Solution Overview

Problem

The existing top cover assembly for batteries faces challenges in controlling the gap between the pole and the pressing plate, leading to deformation and increased assembly difficulty due to either clearance or interference fits, which affects the quality and production cost.

Innovation Solution

A top cover assembly with a cover plate, pressing plate, and pole, where the pressing plate features a variable-section through-hole that allows for a clearance fit with the pole, reducing the risk of deformation and assembly complexity by ensuring accurate fitting without gaps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a clearance fit is defined between the pole and the pressing plate, then the assembly is easier to manufacture, but the gap between the pole and the pressing plate cannot be controlled, resulting in large product differences

Engineering Contradiction:
Improveassembly easeVSAvoidgap control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The through-hole in the pressing plate is designed with a variable cross-sectional area along its length. The first cross-sectional area (at the opening facing the cover plate) is larger than the second cross-sectional area (at the opening facing the battery shell). This parameter change in hole geometry allows the pole to be easily inserted while ensuring precise gap control at the critical welding interface.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If an interference fit is defined between the pole and the pressing plate, then the fit is tight, but the pressing plate is compressed and deformed, increasing assembly difficulty

Engineering Contradiction:
Improvefit tightnessVSAvoidassembly difficulty
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The variable cross-sectional area of the through-hole (larger at the top, smaller at the bottom) creates a transition from clearance fit to interference fit along the insertion path. This allows easy assembly through the larger opening while achieving the required tight fit at the welding interface without deforming the pressing plate.

Inventive Principle:
Principle #35Parameter changes

3Strength

If a tight fit is made between the pole and the pressing plate, then the connection is secure, but the pressing plate deforms under compression

Engineering Contradiction:
Improveconnection strengthVSAvoidpressing plate deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

By designing the through-hole with a variable cross-sectional area that is larger at the opening facing the cover plate and smaller at the opening facing the battery shell, the structure achieves secure connection through controlled interference fit at the critical interface while distributing compression forces to prevent pressing plate deformation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4481912A1Top cover assembly and battery
Publication Date: 2024.12.25 EVE POWER CO LTD
  • EP4481912A1 patent drawingFigure 1~2
  • EP4481912A1 patent drawingFigure 3~4
  • EP4481912A1 patent drawingFigure 5~6A

AI summary

The application discloses a top cover assembly and a battery. The top cover assembly includes a cover plate, a pressing plate and a pole. The cover plate is provided with a first through-hole. The pressing plate includes a first end surface and a second end surface oppositely arranged, and a variable-section through-hole. The pole sequentially passes through the first through-hole and the variable-section through-hole, and the first end surface faces the cover plate. An opening area of an end of the variable-section through-hole toward the first end surface is a1, an opening area of another end of the variable-section through-hole toward the second end surface is a2, and a cross-sectional area of the pole is A, where a1, a2 and A satisfy with: a2≤A<a1.