Welded Structure Cavity Gas Venting Differential Gear
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Solution Overview
Problem
Conventional welding techniques for differential gear components, such as the differential case and ring gear, often result in insufficient weld strength due to compressive and tensile stresses, leading to potential cracks and reduced weld quality, particularly when welding is performed from both sides, causing gas blowholes and non-welded portions that inhibit contraction and create residual tensile stress.
Innovation Solution
A welded structure with a cavity formed between the joint portions of the differential case and ring gear, allowing gas generated during welding to escape, reducing the formation of blowholes and stress at the interface, and incorporating a press-fit portion to maintain alignment and reduce distortion, with welding performed from both ends to form welds along directions inclined relative to the joint surface, enhancing weld strength and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is performed from both sides in the central axis direction of the large gear wheel member, then weld strength is improved, but gas blowholes and non-welded portions are generated causing residual tensile stress
Solution Approach 1:
A cavity is formed in advance at the welding position before welding occurs. This preliminary action provides a predetermined space for gas discharge, preventing gas blowholes and non-welded portions during the welding process while maintaining weld strength and quality
2Stress or pressure
If a groove is provided in the differential case to reduce stress, then stress concentration is reduced, but the groove cannot provide effect at the end on the groove side of the weld beads
Solution Approach 1:
Instead of providing a groove only at one end (one-dimensional solution), the cavity extends in the central axis direction to provide stress relief and gas discharge space at both ends of the weld beads (three-dimensional solution), ensuring comprehensive stress reduction and weld strength improvement
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
The proposed solution improves weld strength and quality by preventing blowholes and residual tensile stress, reducing distortion, and ensuring uniform material distribution, thereby enhancing the durability and reliability of the welded joint.
Implementation Method 1
a cavity which is formed between the first member joint portion and the second member joint portion... allowing gas generated during welding to escape
Implementation Method 2
a welded structure of a first member and a second member joined together by welding... a welded portion which is formed between the cavity and each end in the second direction of a joint surface
Data Source
AI summary
A welded structure and welding method make it possible to improve welding strength and welding quality. A welded structure in which a first member and a second member are joined by welding, wherein the first member comprises a second-member joining part which is joined to the second member, and the second member comprises a first-member joining part which is joined to the first member. If the direction in which the first member and the second member are arranged is the first direction, and the direction intersecting the first direction is the second direction, the welded structure comprises a cavity part which is provided between the first-member joining part and the second-member joining part, and a welded part which is provided between the cavity part and both end parts in the second direction of the joining surface where the first-member joining part and the second-member joining part are joined.