Automotive Airbag Cover Weakening Line Milling Process
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing process for manufacturing automobile interior trim parts with airbag covers is costly and slow, with difficulties in regulating residual thickness and achieving the required functional and perceived quality.
Innovation Solution
A milling process using a six-axis milling machine with a stitching axis to create a weakening line by milling holes and slots, optimizing tear resistance and manufacturing speed, where the milling tool moves perpendicularly to the trim part with controlled acceleration and stroke, allowing for adjustable parameters like hole diameter, slot length, and bridge width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If laser with simple on-off control is used to manufacture holes for creating weakening line, then the process is simple to operate, but the manufacturing speed is slow and cost is high
Solution Approach 1:
The patent replaces the laser-based manufacturing process with a mechanical milling process using a CNC machine. The milling tool with diameter of 4-10 mm mechanically removes material to create holes and slots along the weakening line, substituting optical energy-based laser ablation with mechanical cutting. This mechanical approach enables higher manufacturing speed and better control over residual thickness while maintaining operational simplicity through automated CNC programming.
2Ease of operation
If laser with simple on-off control is used to manufacture holes for creating weakening line, then the process is simple to operate, but the manufacturing cost is high
Solution Approach 1:
The patent replaces the expensive laser manufacturing process with a more cost-effective mechanical milling process. The CNC-controlled milling machine uses a simple milling tool to create the weakening line features, eliminating the need for expensive laser equipment and consumables. The mechanical process allows for better material utilization and lower operational costs while maintaining ease of operation through automated control.
3Device complexity
If laser with simple on-off control is used to manufacture holes, then the control system is simple, but the residual thickness regulation is difficult
Solution Approach 1:
The patent replaces laser-based hole manufacturing with mechanical milling using a tool of diameter 4-10 mm. The mechanical milling process provides superior control over residual thickness because the tool geometry and feed rate can be precisely controlled to leave a consistent residual thickness of 0.1-1 mm between holes. The CNC system controls the milling depth and spacing, enabling precise regulation of residual thickness that is difficult to achieve with laser on-off control.
4Productivity
If milling machine with stitching axis is used to create weakening line by milling holes, then the manufacturing speed increases and cost decreases, but the device complexity increases
Solution Approach 1:
The patent introduces a stitching axis W that moves the milling tool substantially perpendicularly to the zone being milled, adding a new dimension of motion to the conventional three-axis CNC machine. This stitching axis enables rapid reciprocating motion (4-8 m/s² acceleration) that dramatically increases manufacturing speed by efficiently creating multiple holes along the weakening line. The additional axis, with stroke of 1-20 mm, complements the existing X, Y, and Z axes to achieve high-speed hole patterning while maintaining precision through coordinated multi-axis control.
Data Source
AI summary
A process to manufacture a vehicle interior trim with an airbag cover, the process including: obtaining an interior trim part; and creating a weakening line around at least a part of a defined area of said interior trim part, said defined area being the airbag cover, characterized in that the weakening line is created by milling along the weakening line a number of holes, the holes being milled by a milling machine having a milling tool and a stitching axis for moving the milling tool substantially perpendicularly to a zone of the trim part to be milled.