Automotive Lighting Unit Laser Welding for Vibration-Resistant Assembly
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Solution Overview
Problem
The assembly of automotive lighting units is laborious and costly due to the use of self-threading metal screws, which also lead to tool jamming and production line standstills, and existing centring and snap-on locking systems are not robust enough to withstand mechanical vibrations.
Innovation Solution
A method and machine for laser welding internal components directly to the rear casing of automotive lighting units, eliminating the need for self-threading screws and simplifying the assembly process by using laser welding joints to securely fix components made of opaque polymeric material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If self-threading metal screws are used to fix internal lighting components to the rear casing, then the components are securely fixed, but the assembly process becomes laborious and costly, and tool jamming occurs leading to production line standstills
Solution Approach 1:
The patent replaces the mechanical screw-fixing system with a laser welding system. The laser welding apparatus welds the holding components directly to the rear casing, eliminating the need for self-threading screws and manual assembly tools. This substitution resolves the contradiction by providing secure fixing through welding while dramatically improving assembly efficiency and eliminating tool jamming issues.
Solution Approach 2:
The patent changes the fixing method from mechanical (screws) to thermal (laser welding). By using laser beams to melt and fuse the holding components to the rear casing, the process achieves both secure fixation and high-speed automation. This parameter change from mechanical fastening to thermal joining resolves the productivity issue while maintaining reliability.
2Reliability
If self-threading metal screws are used to fix internal lighting components, then secure attachment is achieved, but the weight and cost of the lighting unit increase
Solution Approach 1:
The patent replaces metal screws with laser welding, eliminating the need for additional metal fasteners. The holding components are made of opaque polymeric material that is welded directly to the rear casing, significantly reducing the weight compared to metal screw assemblies while maintaining secure attachment through welding.
Solution Approach 2:
The patent uses holding components made of opaque polymeric material instead of metal screws. These polymeric components are designed to be welded to the rear casing, combining the benefits of lightweight material with strong welding attachment, thus reducing overall weight while maintaining reliability.
3Ease of manufacture
If centring pins and snap-on locking tabs are used to retain internal components, then assembly is simplified, but the system is not robust enough to withstand mechanical vibrations
Solution Approach 1:
The patent replaces the mechanical snap-on locking system with laser welding. The holding components are welded directly to the rear casing, creating a permanent and robust connection that can withstand mechanical vibrations. This substitution maintains ease of manufacture through automated laser welding while dramatically improving vibration resistance.
4Reliability
If multiple fixing elements (screws, centring pins, locking tabs) are used, then components are securely retained, but the device complexity and assembly time increase
Solution Approach 1:
The patent extracts and eliminates the need for multiple fixing elements (screws, centring pins, locking tabs) by using a single laser welding process. The holding components are designed to be directly welded to the rear casing, removing unnecessary intermediate fixing elements and simplifying the overall assembly system while maintaining secure retention.
Solution Approach 2:
The patent merges multiple fixing functions into a single laser welding operation. Instead of using separate centring pins, locking tabs, and screws, the laser welding process simultaneously achieves alignment and secure attachment of the holding components to the rear casing, reducing device complexity while maintaining reliability.
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 approach reduces the weight and cost of the lighting units, eliminates the need for automatic screwdrivers, and simplifies the assembly line by securely fixing components without the need for shoulders, centring pins, or snap-on locking tabs, thereby improving production efficiency.
Implementation Method 1
making at least one laser welding joint (106) at said contact area (105), wherein said making of said at least one laser welding joint (106) comprises directing at least one laser beam (r) towards said outer surface (101e) of said rear casing (101), so that said at least one laser beam (r) passes through a local thickness of said rear casing (101) and heats up to a melting temperature only the opaque polymeric material in the neighbourhood of said contact area (105)
Implementation Method 2
heats up to a melting temperature only the opaque polymeric material in the neighbourhood of said contact area (105)
Implementation Method 3
directing at least one laser beam (r) towards said outer surface (101e) of said rear casing (101), so that said at least one laser beam (r) passes through a local thickness of said rear casing (101)
Data Source
AI summary
An assembly method of an automotive lighting unit and an automotive lighting unit that includes one or more internal components made of opaque polymeric material, which are fixed in abutment on the inner surface of the rear casing at respective contact areas or zones; the assembly method comprising the steps of realizing the rear casing; realizing at least one internal lighting component having at least one portion made of opaque polymeric material; placing said at least one internal lighting component inside the rear casing, with said portion made of opaque polymeric material resting on the rear casing, in at least one contact zone; and making at least one laser welding joint at said contact area, so as to rigidly secure said at least one internal lighting component to the rear casing.