Vehicle Door Link Mechanism With Expandable Arm Near Full Closure
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Solution Overview
Problem
Existing vehicular door devices face instability when the door is near the full closed position due to the linear alignment of first and second link arms, making it difficult to stably support the door during opening and closing operations.
Innovation Solution
A vehicular door device with a first and second link arm configuration that includes a first rotary coupling point with the vehicle body and a second rotary coupling point with the door, featuring a door-side engagement portion with a shaft-shaped engagement portion and a vehicle body-side engagement portion with a guide groove, along with an expansion mechanism that changes the length between these coupling points, allowing for stable support and smooth operation near the full closed position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a link mechanism with first and second link arms is used to support the door, then the door can perform opening-closing operations, but the door becomes unstable near the full closed position due to linear alignment of the link arms
Solution Approach 1:
A guide rail and guide roller unit are introduced as intermediary elements between the door and vehicle body. The guide roller unit engages with the guide rail to constrain the door's movement path, preventing unwanted lateral movement near the full closed position while maintaining smooth opening-closing operations throughout the range of motion.
Solution Approach 2:
The guide rail extends in the vehicle width direction (lateral dimension), adding a constraint in this dimension to control door movement. This dimensional constraint ensures the door follows the intended arc-shaped trajectory without deviating laterally, particularly stabilizing the door near the full closed position where the link arms become linearly aligned.
2Volume of moving object
If the link arms are positioned close together near the full closed position, then the door can achieve a compact closed state, but the door becomes difficult to support stably due to linear alignment
Solution Approach 1:
The guide roller unit acts as a mediator that maintains proper spacing and alignment between the link arms even when they are positioned close together. By engaging with the guide rail, it prevents the link arms from completely collapsing into a linear configuration, thereby maintaining structural stability while achieving a compact closed state.
Solution Approach 2:
The guide rail is configured to guide the door along an arc-shaped trajectory rather than a straight line. This curved path ensures that the link arms maintain an optimal angular relationship even near the full closed position, preventing linear alignment and maintaining stability while achieving compactness.
3Stability of the object's composition
If a guide rail and guide roller unit are added to constrain door movement, then door stability is improved, but device complexity increases
Solution Approach 1:
The guide roller unit serves multiple functions: it guides the door along the correct trajectory, constrains lateral movement, stabilizes the door near the full closed position, and works cooperatively with the link mechanism. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in overall device complexity while achieving improved stability.
Data Source
AI summary
A vehicular door device includes a door-side engagement portion including a guide groove that includes a pair of side wall portions facing each other in a vehicle width direction and extends in an opening-closing operation direction of the door, a vehicle body-side engagement portion including a shaft-shaped engagement portion extending in an up-down direction of a vehicle, and an expansion mechanism provided in a second link arm. In an opening-closing operation position near a full closed position of the door where the door-side engagement portion and the vehicle body-side engagement portion engage with each other, the shaft-shaped engagement portion is disposed in the guide groove. The shaft-shaped engagement portion is relatively displaced along an extending direction of the guide groove while a change in length of the second link arm, based on an operation of the expansion mechanism, is accompanied, and thus the door can perform an opening-closing operation.