Center Pillar Reinforcement with Welding Projections Against Springback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle center pillars face challenges in achieving high surface positional accuracy and bending strength due to springback issues in press forming, particularly with high-strength steel hinge reinforcements used in side collisions.
Innovation Solution
A vehicle reinforcement member with a U-shaped cross section, featuring welding projections that protrude outward over the entire width of the reinforcement lateral walls, providing improved surface position accuracy and bending strength by reducing springback and facilitating press forming efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-strength steel sheet with thickness of 1 to 2 mm and tensile strength of 980 MPa or more is used for hinge reinforcement, then bending strength is improved, but springback increases and surface position accuracy decreases
Solution Approach 1:
The patent applies preliminary action by forming the hinge reinforcement at high temperature before final assembly. The high-temperature press forming process (hot stamping) is performed prior to welding and installation, allowing the material to be shaped while more formable, and then cooled to lock in the desired geometry with reduced springback. This sequential timing of operations resolves the contradiction between achieving high strength and maintaining surface accuracy.
Solution Approach 2:
The patent changes the temperature parameter during the forming process. By heating the high-strength steel sheet to austenite transformation temperature range before press forming, the material becomes more ductile and easier to form complex shapes. After forming, rapid cooling transforms the microstructure and locks in the shape with minimal springback. This parameter change (temperature) enables both high strength and high surface position accuracy.
2Strength
If cross-sectional size of hinge reinforcement is increased to improve bending strength, then strength against side collision is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent changes the material parameter (temperature) to enable formation of complex cross-sectional geometries. By performing hot stamping, the high-strength steel sheet can be formed into intricate U-shaped or hat-shaped cross sections that would be difficult or impossible to achieve at room temperature. The heated material flows more easily into complex die cavities, and upon cooling, retains the complex shape with minimal springback, thus resolving the contradiction between strength and geometric complexity.
3Productivity
If joining projections are arranged at intervals along vehicle height direction, then welding efficiency is improved, but structural continuity and strength are reduced
Solution Approach 1:
The patent applies local quality by varying the distribution and configuration of joining projections along the height of the hinge reinforcement. Rather than uniform spacing, the projections are strategically positioned with different spacing intervals in different zones (e.g., closer spacing in high-stress regions, wider spacing in lower-stress regions). This localized optimization allows efficient welding while maintaining structural continuity where needed, resolving the contradiction between welding efficiency and structural strength.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments include an elongate vehicle reinforcement member having a U-shaped cross section, wherein the vehicle reinforcement member is disposed inside a vehicle structural member and welded to the vehicle structural member, wherein the vehicle structural member comprises opposite base lateral walls, the vehicle reinforcement member comprising: opposite reinforcement lateral walls extending in vehicle height and width directions, each having an outward edge on an outer side in vehicle width direction and an inward edge on an inner side in vehicle width direction, wherein the reinforcement lateral walls are placed along inner sides of the base lateral walls of the vehicle structural member; and a reinforcement connecting wall connecting the outward edges of the reinforcement lateral walls, each reinforcement lateral wall together with the reinforcement connecting wall forming a ridge, each reinforcement lateral wall comprising a row of welding projections, each welding projection protruding outward over the entire width of the reinforcement lateral wall from the ridge to the inward edge of the reinforcement lateral wall, each welding projection having a raised welding surface at which the reinforcement lateral wall is welded to the base lateral wall, the welding projections in each row being arranged at intervals along vehicle height direction.