Reverse Deformation Apparatus for Plastic Battery Pack Case
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Solution Overview
Problem
Plastic battery pack cases for electric or hybrid vehicles deform after compression molding due to uneven heat transfer and crystallization, leading to reduced internal space for battery packs, making it difficult to mount them properly.
Innovation Solution
An apparatus that includes a base with a case insertion space, a fixing portion to prevent inward contraction, and a reverse deformation producing portion that applies a rotational force to convert into a linear motion to press the case's side outwardly, ensuring the internal space is maintained by using a combination of link members, ratchet handles, and bolt portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If compression molding process is used to form plastic battery pack case, then weight reduction is achieved by replacing steel with plastic composite material, but deformation occurs after molding due to uneven heat transfer and crystallization, reducing internal space and making mounting difficult
Solution Approach 1:
The patent applies preliminary action by performing reverse deformation on the case sides before the natural contraction deformation occurs. The reverse deformation producing portion pre-applies outward deformation to compensate for the expected inward contraction, ensuring the case maintains proper dimensions after cooling and crystallization.
Solution Approach 2:
The patent implements preliminary anti-action by applying reverse deformation (outward force) to counteract the expected harmful contraction (inward force). The reverse deformation producing portion generates forces that oppose the natural contraction tendency of the semi-crystalline polymer matrix, preventing dimensional inaccuracies before they fully develop.
2Ease of manufacture
If compression molding is performed without reverse deformation, then manufacturing process is simple, but the case contracts in longitudinal and width directions, reducing internal space for battery packs
Solution Approach 1:
The reverse deformation is applied as a preliminary action immediately after molding while the case is still warm and pliable. This timing allows the deformation to be effectively applied before the material fully crystallizes and contracts, preserving the internal volume needed for battery packs.
Solution Approach 2:
The patent changes physical parameters by applying mechanical force (reverse deformation) to alter the case dimensions. By controlling the magnitude and direction of the reverse deformation, the internal volume is maintained despite the natural contraction tendency of the polymer material during cooling.
3Volume of moving object
If reverse deformation is applied to prevent contraction, then internal space is maintained, but additional apparatus and process steps are required
Solution Approach 1:
The patent replaces complex mechanical deformation systems with a simpler approach using reverse deformation producing portions that generate controlled forces. Instead of using elaborate heating or cooling systems to control crystallization, the invention uses direct mechanical reverse deformation to counteract contraction, simplifying the overall system.
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 apparatus effectively prevents deformation of the plastic battery pack case by allowing it to expand outwardly, ensuring a stable internal space for battery packs and maintaining the case's dimensions, thus facilitating easier mounting and reducing the risk of deformation.
Implementation Method 1
a deformation producing portion inserted into the battery pack case and preventing the case from being deformed by pressing the inside of the case to be reversely deformed in the lateral direction
Implementation Method 2
the polyamide and polypropylene mainly used in the matrix are semi-crystalline polymers and deformed by contraction of the polymer matrix after molding. Such deformation is related to the degree of crystallization of the material depending on the thermal history
Implementation Method 3
After compression molding, heat transfer does not occur uniformly in the plastic battery pack case, and thus a difference in cooling rate occurs to produce a tension in the cooling solid, thereby causing deformation
Data Source
AI summary
Disclosed is an apparatus and method for preventing deformation of a plastic battery pack case for a vehicle, in which the side of the battery pack case is subjected to reverse deformation to absorb the deformation occurring after compression molding and to ensure the dimensions of a mounting portion of various components including battery packs, thereby ensuring an internal space of the battery pack case. To this end, the present invention provides an apparatus for preventing deformation of a plastic battery pack case for a vehicle, the apparatus including: a base having a case insertion space; a fixing portion for fixing a battery pack case inserted into the case insertion space; and a deformation producing portion inserted into the battery pack case and preventing the case from being deformed by pressing the inside of the case to be reversely deformed in the lateral direction.