EV Front Structure With Graded Tunnel Nose for Battery Protection
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Solution Overview
Problem
The existing front structure of electric vehicles is vulnerable to frontal collisions, as the tunnel nose can be pushed downwards during a crash, potentially breaching the battery pack and posing safety hazards due to the absence of an exhaust system, which requires innovative design to absorb energy and protect the battery pack.
Innovation Solution
A front structure design featuring a tunnel nose with a rear portion having a higher ultimate tensile strength-to-thickness product than the front portion, made from high-strength materials like press-hardened or cold-stamped steel, with geometrical alterations to control deformation and absorb energy, preventing the rear portion from breaching the battery pack during a collision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the tunnel nose is made from uniform thickness material, then the manufacturing process is simple, but the rear portion cannot resist the downward force during frontal collision
Solution Approach 1:
The tunnel nose is designed with varying thickness: the rear portion has greater thickness than the front portion. This local quality differentiation allows the rear portion to resist the downward force during frontal collision while keeping the front portion lighter for energy absorption, resolving the contradiction between strength and complexity.
Solution Approach 2:
The thickness parameter of the tunnel nose is changed along its length, with the rear portion having greater thickness. This parameter change enables the structure to provide adequate strength at the rear to resist downward force during collision without requiring uniform thickness throughout, thus avoiding excessive complexity.
2Use of energy by moving object
If the tunnel nose is made from high-strength material, then the energy absorption capacity is improved, but the material cost and manufacturing difficulty increase
Solution Approach 1:
High-strength material is applied locally to the rear portion of the tunnel nose where it is needed to resist downward force, while the front portion uses standard material for energy absorption. This local quality approach improves energy absorption capacity without requiring high-strength material throughout, reducing manufacturing difficulty and cost.
Solution Approach 2:
The tunnel nose is constructed as a composite structure combining different material properties in different regions - high-strength material at the rear and standard material at the front. This composite approach optimizes energy absorption while managing manufacturing complexity and cost.
3Volume of moving object
If the lower dash panel is inclined for space optimization, then the passenger cabin space is optimized, but the tunnel nose is pushed downwards during collision
Solution Approach 1:
The reinforced rear portion of the tunnel nose is designed in advance to counteract the downward force that will be generated during frontal collision. This preliminary anti-action prevents the battery pack from being compromised while maintaining the inclined lower dash panel configuration for space optimization.
Solution Approach 2:
The tunnel nose structure is differentiated with a reinforced rear portion that has greater thickness to resist the downward force generated by the inclined lower dash panel during collision. This local quality enhancement provides the necessary strength without changing the overall inclined configuration for space optimization.
4Use of energy by moving object
If the front portion has high fracture strain, then the energy absorption is improved, but the structural integrity may be compromised
Solution Approach 1:
The front portion of the tunnel nose is designed with high fracture strain material properties to maximize energy absorption during collision, while the rear portion uses greater thickness to maintain structural integrity and resist downward force. This local quality differentiation resolves the contradiction between energy absorption and structural integrity.
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 design effectively controls the deformation of the tunnel nose during a frontal crash, preventing battery pack damage and optimizing energy absorption, thereby enhancing passenger and rescue team safety while adhering to crash test standards like FMVSS 208.
Implementation Method 1
the front portion is made from a material having a fracture strain of at least 0,6 and a critical bending angle of at least 75°
Implementation Method 2
the front portion is made from a material having a fracture strain of at least 0,6
Implementation Method 3
the product of the ultimate tensile strength by the average thickness of the rear portion is greater than the product of the ultimate tensile strength by the average thickness of the front portion
Data Source
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AI summary
Front structure for an electric vehicle comprising a lower dash panel, a seat cross-member and a tunnel nose, such that the tunnel nose is designed to absorb energy in its front portion while resisting intrusion in its rear portion, optimizing the energy absorption in the part during a front crash and protecting the battery pack from being breached by the downward pushing effect of the lower dash panel.