Vehicle Door Frame Cantilever Protrusion Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vehicle door frame welding process is prone to damage and burn-through due to high heat generated during welding, especially when thin-walled protrusions are involved, which can lead to deformation or damage of the door frame.
Innovation Solution
A vehicle door frame structure with an upright pillar sash and an upper sash that includes a cantilever protrusion, where the welding is performed along the frame body portion and the base portion of the cantilever protrusion, excluding the narrow width portion at the leading end to prevent heat damage, and the cantilever protrusion can serve as a weather strip retaining element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is performed along the periphery of the joined end surfaces of the upright pillar sash and upper sash, then joining strength is improved, but the thin-walled protrusion portions are prone to burn-through and damage due to high heat
Solution Approach 1:
The protrusion is segmented into two distinct portions: a base portion with larger cross-sectional area that is welded, and a leading end portion with smaller cross-sectional area that is not welded. This segmentation allows the welding heat to be concentrated on the more heat-resistant base portion while protecting the thinner leading end portion from burn-through.
Solution Approach 2:
Different portions of the protrusion are given different properties: the base portion has larger dimensions and is designed to withstand welding heat, while the leading end portion has smaller dimensions and is excluded from welding to prevent damage. This local differentiation of properties resolves the contradiction between achieving strong joints and protecting vulnerable areas.
2Device complexity
If the door frame uses thin-walled protrusions for structural features, then device complexity is reduced, but the risk of burn-through during welding increases
Solution Approach 1:
The protrusion design incorporates local quality variation where the base portion has larger cross-sectional dimensions providing heat resistance, while the leading end portion has smaller dimensions maintaining structural simplicity. This allows the overall simple structure to be maintained while specific areas are optimized for welding resistance.
Solution Approach 2:
The protrusion is divided into functional segments: the base portion serves as the welding zone with adequate heat resistance, while the leading end portion serves as a non-welded structural element. This segmentation enables the thin-walled structure to maintain simplicity while avoiding burn-through by excluding the vulnerable leading end from welding.
3Reliability
If the cantilever protrusion base portion has larger cross-sectional area, then welding heat resistance is improved, but the overall door frame weight increases
Solution Approach 1:
Only the base portion of the protrusion, which requires welding, is given larger cross-sectional area for heat resistance. The leading end portion maintains smaller dimensions to minimize weight. This localized increase in material only where necessary resolves the contradiction between welding resistance and weight reduction.
Solution Approach 2:
The protrusion is segmented such that only the base portion承担着 the welding function and requires adequate mass for heat resistance, while the leading end portion is minimized for weight reduction. This functional segmentation allows the door frame to achieve sufficient welding heat resistance without excessive overall weight increase.
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 enhances the prevention of damage to the door frame during welding by managing heat exposure and maintains the structural integrity and joining strength between the sashes.
Implementation Method 1
joining end surfaces of an upright pillar sash and an upper sash are butted and joined together by welding along a periphery of the joining end surfaces
Data Source
AI summary
A door frame structure of a vehicle door which includes an upright pillar sash and an upper sash, wherein joining end surfaces of the upright pillar sash and the upper sash are welded together along a periphery thereof, at least one of the upright pillar sash and the upper sash includes a frame body portion and a cantilever protrusion, the joining end surface of the one of the upright pillar sash and the upper sash partly including the frame body portion and the cantilever protrusion. The upright pillar sash and the upper sash are welded to each other along the frame body portion and a base portion of the cantilever protrusion which is connected to the frame body portion. A leading end portion of the cantilever protrusion which is positioned on the leading end side is not welded.