Battery Pack Case Assembly Using Plastic Composite
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery pack case assemblies for electric and hybrid vehicles face challenges in reducing weight while maintaining structural stiffness, collision characteristics, and dimensional stability, particularly due to the use of steel materials which increase vehicle weight and are prone to shrinkage and distortion.
Innovation Solution
A battery pack case assembly formed partially from a plastic composite with reinforcing fibers, specifically long fibers or a blend of long and continuous fibers, is used for the case body and separate reinforced members, which are bonded to side bracket parts for improved structural integrity and weight reduction, employing extrusion-compression molding to minimize residual stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If steel materials are used for the lower case and structure-reinforcing members, then structural stiffness and durability are ensured, but the total weight of the battery pack case assembly increases
Solution Approach 1:
The patent applies composite materials by combining plastic matrix with long fibers (aspect ratio ≥ 100) to create a fiber-reinforced plastic composite for the lower case and structure-reinforcing members. This composite structure provides steel-level structural stiffness and durability while significantly reducing weight, as the high aspect ratio fibers efficiently carry loads without requiring the thick steel sections traditionally needed
Solution Approach 2:
The patent changes the material parameters by using plastic composite with high aspect ratio fibers (≥100) instead of steel materials. This parameter change in fiber aspect ratio enables the plastic composite to achieve sufficient structural stiffness and durability while reducing density from steel levels (≈7.8 g/cm³) to plastic composite levels (≈1.5-2.0 g/cm³), thereby reducing total weight while maintaining strength
2Weight of moving object
If plastic composite is used for the lower case, then weight is reduced, but shrinkage and distortion occur due to molding conditions and temperature fluctuations
Solution Approach 1:
The patent changes the fiber aspect ratio parameter to ≥100, which fundamentally alters the composite's thermal and dimensional behavior. Long fibers act as rigid scaffolds that constrain polymer matrix shrinkage during cooling and limit thermal expansion/contraction variations, thereby improving dimensional stability while maintaining the weight advantages of plastic composite
Solution Approach 2:
The patent uses fiber-reinforced plastic composite where long fibers (aspect ratio ≥100) embedded in the plastic matrix create a hybrid structure that combines the low density and moldability of plastics with the dimensional stability and rigidity of fiber reinforcements, effectively suppressing shrinkage and distortion issues inherent in plain thermoplastics
3Strength
If steel reinforced material is inserted into plastic composite, then structural integrity is improved, but manufacturing complexity and part quantity increase
Solution Approach 1:
The patent merges the reinforcement function and case structure into a single integrated plastic composite component. By incorporating long fibers (aspect ratio ≥100) directly into the plastic matrix during molding, the structure-reinforcing members and lower case become one unified part, eliminating the need for separate steel reinforcements and reducing assembly steps
Solution Approach 2:
The patent uses fiber-reinforced plastic composite as a monolithic material that combines structural integrity and reinforcement functions within a single moldable material system, replacing multi-component steel-plastic hybrid constructions with a unified composite part that is manufactured in one molding operation
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 solution achieves a significant reduction in weight, enhances structural stiffness and collision characteristics, and improves dimensional stability, allowing for the omission of additional steel reinforcing members and reducing manufacturing costs.
Implementation Method 1
the case body is formed of a plastic composite in which a reinforcing fiber is provided in a plastic matrix
Implementation Method 2
employing extrusion-compression molding to minimize residual stresses
Data Source
AI summary
Disclosed is a battery pack case assembly for an electric or hybrid vehicle and a method for manufacturing the same. The battery pack case assembly includes a case body and a cover. The case body receives a battery pack, and the cover is coupled to the case body. The case body is formed of a plastic composite in which a long fiber or a blend of a long fiber and a continuous fiber is used as a reinforcing fiber in a plastic matrix. A separate reinforced member is bonded to both side bracket parts for coupling to a vehicle body, and is formed of a plastic composite in which a long fiber, a continuous, or a blend of a long fiber and a continuous fiber is used as the reinforcing fiber in the plastic matrix.