Vehicle Door Reinforcing Member Fixing Structure
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Solution Overview
Problem
The existing vehicle door structures face issues with insufficient fixing strength of the reinforcing member at the lower end portion, leading to a risk of the reinforcing member falling off during a side collision, which compromises the transmission of collision loads to the side sill and desired collision performance.
Innovation Solution
A vehicle door structure with a reinforcing member integrally formed with the outer door panel, comprising a cylindrical body of fiber-reinforced resin filled with foamed polyethylene and a hat-shaped fixing member made of fiber-reinforced resin, which is sandwiched between the inner and outer door panels, providing enhanced fixation and integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a locking body is used to fix the reinforcing member to the outer door panel, then the structure is simple and easy to manufacture, but the fixing strength is insufficient and the reinforcing member may fall off during side collision
Solution Approach 1:
The reinforcing member is integrally formed with the outer door panel through co-molding, merging two previously separate components (outer door panel and reinforcing member) into a single integrated structure. This eliminates the need for separate locking bodies and achieves superior fixing strength while maintaining manufacturing efficiency through one-step co-molding process
Solution Approach 2:
The outer door panel and reinforcing member are both made of fiber-reinforced resin materials with similar properties, allowing them to be integrally formed. The use of composite materials enables the reinforcing member to be seamlessly integrated with the outer door panel, providing both structural strength and adequate fixing strength
2Reliability
If the reinforcing member is only joined to the outer door panel at one location, then the manufacturing process is simple, but the collision load cannot be reliably transmitted to the side sill
Solution Approach 1:
The reinforcing member is joined to the inner door panel at multiple locations including the first side surface, second side surface, and lower end surface, transitioning from single-point attachment to multi-dimensional distributed attachment. This multi-point joining approach ensures reliable collision load transmission to the side sill while maintaining manufacturing simplicity through integral formation
3Stability of the object's composition
If the reinforcing member is made separate from the outer door panel, then the components can be manufactured independently and assembled, but the integration between the reinforcing member and door is insufficient
Solution Approach 1:
The outer door panel and reinforcing member are integrally formed through co-molding, merging two separate manufacturing processes into a single simultaneous operation. This achieves maximum integration strength while maintaining high productivity through one-step manufacturing
Solution Approach 2:
Both the outer door panel and reinforcing member are made of the same fiber-reinforced resin material, creating homogeneous composition throughout the integrated structure. This material homogeneity ensures consistent mechanical properties and strong integration between the reinforcing member and door panel
Data Source
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AI summary
A vehicle door structure comprising a reinforcing member (8) that is extended along a side sill (6) on an inner door panel (4) side of a lower portion of an outer door panel (5). The reinforcing member (8) has a first side surface (A1) that faces the side sill (6) in the vehicle width direction, and a second side surface (A2) that extends from the first side surface (A1) to the outer door panel (5) side, and the first side surface (A1) and the second side surface (A2) are joined to the inner door panel (4).