Wheel Arch and Front Side Member Structure for Collision Energy Absorption

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Solution Overview

Problem

Existing vehicle designs with single-piece casting members having an open cross-section structure face challenges in achieving both sufficient energy absorption and stiffness due to the open structure, which compromises the vehicle's ability to manage frontal collisions effectively.

Innovation Solution

The vehicle design incorporates a single-piece casting member with right and left wheel arches and a cross member connected by a side member, where the side member is fixed to the wheel arches, forming a closed cross-section structure to enhance stiffness and energy absorption, and includes a front side member with a closed cross-section to improve impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the wheel arches and cross member are molded as a single-piece casting member with an open cross-section structure, then the manufacturing complexity is reduced and production efficiency is improved, but the stiffness of the structure is lowered

Engineering Contradiction:
Improveproduction efficiencyVSAvoidstiffness
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The single-piece casting member is divided into multiple sections along the vehicle width direction, with coupling parts provided at predetermined locations. This segmentation allows the structure to maintain the benefits of single-piece casting while introducing reinforcement elements that improve stiffness without requiring a complete redesign to closed cross-section.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Reinforcement ribs are strategically positioned at specific locations within the open cross-section structure, particularly at the coupling parts and high-stress areas. This local reinforcement approach maintains the overall open cross-section design for manufacturing efficiency while providing targeted stiffness enhancement where most needed.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the front side members are designed with open cross-section structure to simplify manufacturing, then the ease of manufacture is improved, but the energy absorption capability during frontal collision is reduced

Engineering Contradiction:
Improveease of manufactureVSAvoidenergy absorption capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The front side members maintain open cross-section for manufacturing ease, but reinforcement ribs are strategically positioned at high-stress zones during collision. This localized reinforcement provides the necessary energy absorption capability while preserving the manufacturing advantages of the open cross-section design.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The reinforcement ribs are pre-positioned within the casting structure to prepare for collision loads. These ribs are formed during the manufacturing process itself, so no additional assembly steps are needed, and the structure is ready to absorb energy when collision occurs.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the single-piece casting member uses an open cross-section structure, then the device complexity is reduced, but the structural deformation resistance during collision is compromised

Engineering Contradiction:
Improvestructural complexityVSAvoiddeformation resistance
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

Rather than redesigning the entire cross-section to closed form, reinforcement ribs are selectively added at critical locations within the open cross-section. This maintains the simplicity of the overall design while providing targeted deformation resistance where collision forces are most concentrated.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The open cross-section is divided into multiple segments by reinforcement ribs, creating a more complex internal structure that resists deformation while maintaining the external simplicity of an open cross-section design. This segmented approach provides deformation resistance without requiring a complete structural redesign.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4578765A1vehicle
Publication Date: 2025.07.02 TOYOTA JIDOSHA KK
  • EP4578765A1 patent drawingFigure 1
  • EP4578765A1 patent drawingFigure 2
  • EP4578765A1 patent drawingFigure 3

AI summary

A front side member (38) is provided as a separate body from a single-piece casting member (24) including a wheel arch (12). Thus, even when the wheel arch (12) itself has an open cross-section structure, a lower part of the wheel arch (12) can have a closed cross-section structure by fixing the front side member (38) to the lower part of the wheel arch (12). For this reason, even with a configuration including the single-piece casting member (24) having a so-called open cross-section structure, which makes it possible to improve stiffness in the wheel arch (12) including the front side member (38), an energy absorption amount can be ensured.