Automotive Door Sash Roll-Forming Gap Elimination
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Solution Overview
Problem
The existing door sash for automobile windows experiences rust due to water stagnation in gaps between overlapping plate materials, which is difficult to seal and affects the close contact between welded surfaces, hindering manufacturing efficiency and adhesion of coating materials.
Innovation Solution
A door sash formed by roll-forming with a weather strip, where the end portion of the plate material protrudes inwardly to enhance contact with the overlapping section, reducing gaps and improving weld contact, and is welded close to the center of gravity for easier bending and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is formed between overlapping plate materials and the holder, then the door sash structure is simple, but water stagnates in the gap causing rust
Solution Approach 1:
Instead of adding a separate seal material to close the gap, the invention inverts the approach by making the plate material itself form the seal. The end portion of the plate material is formed to protrude and come into contact with the overlapping section, eliminating the gap without requiring additional sealing components.
Solution Approach 2:
The plate material serves dual functions: structural component and seal. The end portion of the plate material automatically seals the gap through its own deformation and contact with the overlapping section, eliminating the need for separate seal materials or additional sealing steps.
2Reliability
If seal material is applied to the gap, then rust is prevented, but manufacturing process efficiency is reduced
Solution Approach 1:
The plate material self-seals the gap through its own geometric configuration and deformation during roll-forming. The end portion protrudes and contacts the overlapping section, creating a seal without requiring any additional sealing operations or materials, thus maintaining manufacturing efficiency.
Solution Approach 2:
The sealing function is extracted from the separate seal material application process and integrated into the plate material itself. By forming the end portion of the plate material to protrude and contact the overlapping section, the sealing action is built into the manufacturing process rather than being a separate post-processing step.
3Reliability
If seal material is applied to the gap, then rust is prevented, but labor is required due to poor adhesion
Solution Approach 1:
The plate material creates its own seal through mechanical contact. The end portion protrudes and physically contacts the overlapping section, forming a gap-free seal through the plate material's own geometry and deformation rather than relying on adhesive bonding of separate seal materials.
Solution Approach 2:
The sealing function is extracted from the adhesive bonding process and achieved through direct mechanical contact of the plate material with the overlapping section. This eliminates the adhesion problem entirely by using the plate material's own form to create the seal.
4Manufacturing precision
If the end portion of plate material does not protrude, then manufacturing is simpler, but close contact between welded surfaces is poor
Solution Approach 1:
The plate material is pre-formed during the roll-forming process to have its end portion protrude. This preliminary deformation ensures that when the plate material is assembled and welded, the end portion is already positioned to make close contact with the overlapping section, guaranteeing proper welded surface contact.
Solution Approach 2:
The geometric parameters of the plate material are changed during roll-forming to create the protruding end portion. By controlling the deformation and shape of the end portion during forming, the plate material achieves the precise geometry needed for close contact with the overlapping section at the welding interface.
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
Prevents rust by eliminating gaps between plate materials, enhances the close contact between welded surfaces, reduces weight, and simplifies the manufacturing process while improving bending accuracy and reducing labor costs.
Implementation Method 1
the vicinity of an end portion of the plate material forming the overlapping section, in which deformation has occurred during the roll-forming, protrudes to the inside of the tubular section
Implementation Method 2
an overlapping section formed by making the plate materials overlap each other
Data Source
AI summary
A door sash which is formed by roll-forming from a single plate material and in which a weather strip is fitted includes: an overlapping section formed by making the plate materials overlap each other; a tubular section formed to extend from a car-interior-side end portion of the overlapping section; and flange sections and respectively formed to protrude from a car-exterior-side end portion of the overlapping section to both sides, in which a periphery of an end portion of the plate material extending from the tubular section is formed so as to come into contact along a plate material forming the overlapping section on the side on which the weather strip is fitted, and the vicinity of an end portion of the plate material forming the overlapping section, in which deformation has occurred during the roll-forming, protrudes to the inside of the tubular section.