Door Ring Welding Fixture With Backlit Vision Seam Alignment
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Solution Overview
Problem
Existing automatic assembly fixtures for automotive door rings face issues with compact part placement, low positioning accuracy, complex and failure-prone mechanisms, and difficulty in handling coated surfaces, leading to reduced welding quality and increased defects.
Innovation Solution
An alignment clamping fixture with a gripper unit and clamp unit, featuring a gripper frame with vision cameras and suction cups, and clamp mechanisms with backlit illumination, allowing for flexible and accurate alignment of welded seams using a robotic arm, vision cameras, and adjustable light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If all mechanisms and components are fixed on a base plate, then the structure is compact, but the steel plates cannot be placed when assembling door rings with four or more welded seams
Solution Approach 1:
The fixture is divided into a base plate and multiple independently adjustable support modules. Each support module can be positioned and adjusted separately, allowing the fixture to accommodate door rings with different numbers of welded seams (3-10 seams) while maintaining a compact overall structure.
2Length of moving object
If the vision camera is fixed on a rotary driving device which is fixed on a lift driving device (cantilever structure), then the camera can reach the work area, but the repeated positioning accuracy cannot reach 0.02 mm due to cantilever length
Solution Approach 1:
A precision positioning platform is introduced as an intermediary between the drive mechanisms and the vision camera. This platform provides a stable mounting base with high repeatability positioning accuracy (≤0.02mm), eliminating the accuracy degradation caused by the cantilever structure while maintaining the camera's ability to reach the work area.
3Illumination intensity
If an integrated light source is disposed on the vision camera component to directly project light onto the steel plates, then illumination is provided, but the side lines of the steel plates are blurred due to reflection from coated surfaces
Solution Approach 1:
Instead of projecting light from above (causing reflections), the light source is inverted to illuminate the steel plates from below. This bottom illumination approach allows light to pass through the material or reflect from the back surface, eliminating glare and blurred edge lines caused by front surface reflections from coated surfaces, thereby improving edge detection clarity.
4Ease of operation
If a mechanical pushing method is used to implement alignment, then the steel plates are positioned, but the outer contour shape deviations accumulate to the last welded seam, resulting in a gap
Solution Approach 1:
The system uses vision cameras to detect the actual positions and orientations of steel plates, and the control unit calculates precise positioning adjustments based on detected deviations. This closed-loop feedback mechanism compensates for cumulative tolerance accumulation, ensuring the gap at the last welded seam is controlled within 0.05mm without complex mechanical pushing adjustments.
5Ease of operation
If the rotary driving device and lift driving device are used, then the vision camera can be positioned, but the repeated positioning accuracy is low and the structures are complex with high failure rate
Solution Approach 1:
The complex rotary driving device and lift driving device structures are extracted and replaced with a simplified precision positioning platform. This platform achieves the necessary camera positioning capability with reduced structural complexity and lower failure rate, while maintaining or improving positioning accuracy.
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
Improves positioning accuracy to ≤±0.05 mm, reduces defects, and enhances welding quality by uniformly distributing seam tolerances, increasing production efficiency and reducing material waste.
Implementation Method 1
a plurality of suction cup mechanisms (6) are mounted at a bottom of the gripper frame (2) in a fit manner, respectively, the gripper unit sucks up the workpiece (12) by the suction cup mechanisms (6)
Implementation Method 2
a light source (803) is arranged in each individual first alignment mechanism (8), the light source (803) is disposed below the workpiece (12), and the light source (803) illuminates the workpiece (12) from a back surface of the workpiece (12)
Data Source
AI summary
The provided is an alignment clamping fixture for automatic tailor welding of an automotive door ring and a welded seam alignment method therefor. The alignment clamping fixture includes a gripper unit and a clamp unit, where the gripper unit is connected to a working end of a robotic arm; the gripper unit includes a gripper frame, and a plurality of vision camera mechanisms and a plurality of suction cup mechanisms are mounted at a bottom of the gripper frame in a fit manner, respectively; and the clamp unit includes a clamp base, a plurality of first alignment mechanisms are mounted at a top of the clamp base in a fit manner, the first alignment mechanisms are configured to clamp a workpiece, a light source is arranged in an individual first alignment mechanism, and the light source illuminates the workpiece from a back surface of the workpiece.