Resin-Coated Crash Box Structure for Stronger Axial Energy Absorption
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Solution Overview
Problem
Existing automotive crashworthiness energy absorption parts, such as front side members and crash boxes, face challenges in improving crashworthiness energy absorption due to insufficient adhesive strength between the parts and the foamed filler or foaming body, leading to potential separation during crashes.
Innovation Solution
The solution involves coating or patching the outer surfaces of tubular members with a resin of thickness 8 mm or less, ensuring an adhesive strength of 10 MPa or more, and optionally using a separation prevention member to prevent resin separation during axial crush.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the inside of automotive parts is filled with foamed filler or foaming body, then the strength and crashworthiness energy absorptive property are improved, but the adhesive strength between the part and filler is insufficient causing the filler to blow out during crash
Solution Approach 1:
The patent applies composite materials by combining metal automotive parts with resin materials (foamed resin or solid resin) to create a hybrid structure. The resin is coated on the inner surface of the metal part, forming a composite structure that leverages the strength of metal and the energy absorption properties of resin, resolving the contradiction between improving crashworthiness and maintaining adhesive strength.
Solution Approach 2:
The patent changes the physical and chemical parameters of the resin material, including its thickness (controlled to be 3mm or less), density (through foaming ratio control), and adhesive properties. By optimizing these parameters, the resin achieves sufficient adhesive strength to prevent blowout while maintaining crashworthiness energy absorption capabilities.
2Reliability
If the resin coating thickness is increased to improve adhesive strength, then the adhesive strength is improved, but the weight of the automotive part increases
Solution Approach 1:
The patent optimizes the resin thickness parameter to be 3mm or less, which is sufficient to provide the required adhesive strength (10 MPa or more) while minimizing weight increase. This parameter optimization resolves the contradiction between achieving sufficient adhesive strength and controlling part weight.
Solution Approach 2:
The patent employs foamed resin with controlled porosity to reduce density and weight. The foamed structure provides adequate adhesive strength and energy absorption properties while significantly reducing the weight compared to solid resin of the same thickness.
3Strength
If the resin is coated on the outer surface of tubular members, then the buckling strength is enhanced and fractures are prevented, but the manufacturing complexity increases
Solution Approach 1:
This principle is not applicable to this patent as it deals with mechanical properties rather than optical properties.
Solution Approach 2:
The resin coating is applied to the tubular member outer surface during the manufacturing process before the part is assembled into the vehicle. This preliminary action ensures the coating is already in place to provide buckling strength and fracture prevention, simplifying the overall manufacturing process by combining coating and forming operations.
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
This approach enhances the buckling strength of the tubular members, prevents fractures during bellows-shaped buckling deformation, and improves crashworthiness energy absorption properties while also serving as a damping material to absorb vibrations.
Implementation Method 1
bonded to the outer surfaces with an adhesive strength of 10 MPa or more
Implementation Method 2
capable of functioning as a damping material that absorbs vibrations
Implementation Method 3
absorbs crashworthiness energy by undergoing axial crush when receiving input of a crashworthiness load
Data Source
Figure 1~2
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Figure 5~6
AI summary
An automotive crashworthiness energy absorption part 1 according to the present invention is provided at a front part or a rear part of an automotive body and absorbs crashworthiness energy when receiving input of a crashworthiness load from the front or the rear of the automotive body and includes: a tubular member 3 configured to absorb crashworthiness energy by undergoing axial crush and including a top portion and side wall portions continuous with the top portion; and resin 9 coated or patched on at least outer surfaces of the top portion and the side wall portions of the tubular member 3. The coated or patched resin 9 has a thickness of 8 mm or less after being heated, forms at least part of a peripheral wall portion of a closed cross section space, and is bonded to the outer surfaces with an adhesive strength of 10 MPa or more.