Vehicle Battery Case Side Wall Deformation Control
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Solution Overview
Problem
Existing battery cases for electric vehicles with steel components face challenges in manufacturing cost, weight, and deformation under lateral loads due to the need for spot welding openings and insufficient load transmission to cross-beams, leading to potential battery damage.
Innovation Solution
A battery case design featuring a closed cross-section side wall with inner and outer panels joined by spot welding, where the panels are formed with bulging portions to suppress deformation and eliminate the need for welding openings, using steel or light metal components for reduced costs and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If openings are formed in the outer frame for spot welding, then the side wall can be joined to supporting members, but the strength of the outer frame at the opening portions decreases and additional closing-off members are needed
Solution Approach 1:
Instead of forming openings in the outer frame to access the inner frame for welding, the patent inverts the approach by forming openings in the inner frame. This allows the spot welding gun to access the inner frame from the battery accommodation space side, eliminating the need for openings in the outer frame and preserving its structural integrity.
Solution Approach 2:
The inner frame acts as an intermediary that provides access to the welding zone. By forming openings in the inner frame rather than the outer frame, the design allows welding operations to proceed while maintaining the outer frame's strength. The inner frame openings serve as the intermediary access path for the welding gun.
2Strength
If inner frames are disposed within the tray to suppress side wall deformation, then deformation is reduced, but the space for accommodating the battery is reduced
Solution Approach 1:
The patent extracts the deformation suppression function from the inner frame and transfers it to the outer frame. By forming bulging portions in the outer frame that extend toward the inner frame, the outer frame directly provides deformation resistance, eliminating the need for inner frames and maximizing battery accommodation space.
Solution Approach 2:
The patent introduces a new dimensional feature - bulging portions extending in the width direction of the battery case. These bulging portions create a three-dimensional structural reinforcement that suppresses side wall deformation without occupying vertical space that would reduce battery accommodation volume.
3Strength
If the side wall has a closed cross-sectional shape, then structural integrity is improved, but it is difficult to transmit load to cross beams when the side wall is crushed
Solution Approach 1:
The patent introduces curvature by forming bulging portions in the outer frame. These bulging portions create a curved, arch-like structure that efficiently transmits lateral loads to the cross beams. The curved geometry of the bulging portions allows force to be distributed and transmitted along the arc to the supporting cross beams, maintaining both structural integrity and load transmission capability.
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 design efficiently suppresses side wall deformation under lateral loads without forming welding openings, reduces manufacturing costs, and ensures effective load transmission to cross-beams, enhancing the structural integrity and efficiency of the battery case.
Implementation Method 1
upper portions of the inner panel and the outer panel are joined together by spot welding
Implementation Method 2
at a vertical direction intermediate portion of one of the inner panel or the outer panel, there is formed a bulging portion which bulges out toward another of the inner panel or the outer panel
Data Source
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AI summary
In a battery case (10) for a vehicle that houses a battery, at a vertical direction intermediate portion of one of an inner panel (22) or an outer panel (24), there is formed a bulging portion (26) which bulges out toward another of the inner panel (22) or the outer panel (24) and is joined to the other of the inner panel (22) or the outer panel (24) by spot welding, closed cross-section portions (28, 30) are formed at a side wall (20) at both an upper side and a lower side of the bulging portion (26), respectively, and weld points of the spot welding that join the inner panel (22) and the outer panel (24) are disposed at positions that do not overlap with supporting members (40) as seen from a direction in which the inner panel (22) and the outer panel (24) face one another.