Dissimilar-Metal Junction Structure With Weld Exhaust Grooves
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Solution Overview
Problem
Conventional methods for joining different types of materials, such as spot welding, are limited by high production costs, time-consuming processes, and design restrictions, particularly when combining light metals and steel, leading to inefficient joining and potential defects like uneven melting and current diversion.
Innovation Solution
A rivet-joined structure featuring a weld zone with exhaust grooves or holes around the weld area, allowing for the use of laser, arc, or plasma welding, which enables the reliable joining of dissimilar materials by managing heat and gas exhaust, reducing misalignment issues and improving design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spot welding is used to join different types of materials, then joining strength is achieved, but production time increases due to pressurization, energization, cooling, and transfer steps
Solution Approach 1:
The patent replaces the mechanical pressurization system of spot welding with a laser-based thermal welding system. The laser beam delivers energy directly to the weld zone without requiring mechanical contact or pressurization, eliminating the time-consuming steps of pressurization, energization, and cooling while maintaining joining strength between different materials
2Reliability
If conventional rivets are used to join different types of materials, then misalignment protection is provided, but manufacturing cost increases due to high precision processing requirements
Solution Approach 1:
The patent extracts the misalignment protection function from the complex rivet structure and implements it through the laser welding process itself. The laser beam's inherent precision and the weld zone's design provide automatic alignment tolerance, eliminating the need for expensive precision-machined rivets with radius-chamfered parts or annular grooves
3Strength
If adjacent rivets are placed close to each other to improve joining stiffness, then design flexibility increases, but current diversion occurs during spot welding
Solution Approach 1:
The patent replaces the electrical resistance welding process with laser welding, which does not suffer from current diversion effects. The laser beam can weld adjacent points without the electrical interference that plagues spot welding, allowing rivets to be placed closer together to improve joining stiffness without compromising welding quality
4Weight of moving object
If light metal materials are used to reduce vehicle weight, then fuel efficiency improves, but joining difficulty increases when combining with steel
Solution Approach 1:
The patent changes the welding parameters by using laser welding instead of spot welding. This allows for precise control of heat input and welding speed, enabling reliable joining of dissimilar materials like light metal and steel without the limitations of conventional resistance welding methods
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 significantly reduces production cycle time, enhances joining stiffness, and increases design freedom while preventing defects like uneven melting and current diversion, resulting in a more efficient and reliable joining process.
Implementation Method 1
at least one weld zone where the at least one similar metallic material is melted and joined together by using laser, arc, or plasma as the heat source
Implementation Method 2
at least one weld zone where the at least one similar metallic material is melted and joined together by using laser, arc, or plasma as the heat source
Implementation Method 3
at least one weld zone where the at least one similar metallic material is melted and joined together by using laser, arc, or plasma as the heat source
Implementation Method 4
at least one exhaust groove or at least one exhaust hole around the at least one weld zone, the at least one exhaust groove or the at least one exhaust hole extending along a thickness of the at least one similar metallic material
Data Source
AI summary
A junction structure includes a first material that is a metallic material, a third material that is a metallic material and is weldable to the first material, and a second material which is a nonferrous metallic material or a nonmetallic material. The second material is sandwiched and fixed between the first material and the third material by lap joining. At least one of the first material or the third material has a weld zone where the first material and the third material are melted and joined together, and at least one exhaust groove or at least one exhaust hole around the weld zone. The at least one exhaust groove or the at least one exhaust hole penetrates a thickness of the at least one of the first material or the third material.