Crane Girder Splice Joint Using Reversed Tongue-and-Groove Web
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Solution Overview
Problem
Conventional splice joints for cranes, such as flange and strapped joints, are complex, costly, and prone to deformations due to high heat input during welding, requiring extensive machining and precise alignment of numerous bolts, which complicates the manufacturing and assembly process.
Innovation Solution
A tongue-and-groove joint system is implemented on both sides of the central web, with reversed tongue-and-groove configurations to simplify alignment and assembly, and a lower flange joint to manage bending forces, utilizing fewer joining elements and minimizing heat input, allowing for easier manufacturing and assembly without extensive machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a flange joint with multiple bolts is used to connect main girder parts, then the connection strength is improved, but the device complexity and manufacturing cost increase due to the large number of joining elements and alignment requirements
Solution Approach 1:
The connection is segmented into two functional parts: a tongue-and-groove joint for shear forces and a flange joint for bending forces. This segmentation allows each connection element to be optimized for its specific function, reducing the overall complexity while maintaining strength.
Solution Approach 2:
The invention merges two traditional connection methods (tongue-and-groove and flange joint) into a single hybrid system. The tongue-and-groove joint handles shear forces with minimal alignment requirements, while the flange joint handles bending forces, combining the advantages of both approaches.
2Strength
If welding is used to join main girder parts, then the connection strength is improved, but manufacturing precision deteriorates due to deformations caused by large local heat input
Solution Approach 1:
The connection is segmented into two functional parts: a tongue-and-groove joint for shear forces and a flange joint for bending forces. This segmentation allows each connection element to be optimized for its specific function, reducing the overall complexity while maintaining strength.
Solution Approach 2:
The invention merges two traditional connection methods (tongue-and-groove and flange joint) into a single hybrid system. The tongue-and-groove joint handles shear forces with minimal alignment requirements, while the flange joint handles bending forces, combining the advantages of both approaches.
3Strength
If a strapped joint with multiple bolts is used to connect main girder parts, then the connection strength is improved, but the ease of manufacture deteriorates due to demanding alignment procedures and high manufacturing costs
Solution Approach 1:
The connection is segmented into two functional parts: a tongue-and-groove joint for shear forces and a flange joint for bending forces. This segmentation allows each connection element to be optimized for its specific function, reducing the overall complexity while maintaining strength.
Solution Approach 2:
The invention merges two traditional connection methods (tongue-and-groove and flange joint) into a single hybrid system. The tongue-and-groove joint handles shear forces with minimal alignment requirements, while the flange joint handles bending forces, combining the advantages of both approaches.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a splice joint (5) of a main girder (1) of a crane, whereby the main girder (1) comprises at least two longitudinal main girder parts (la) to be connected to each other by their ends and each having a central web (2) which comprises at least one web plate (2a), a longitudinal upper flange (3) or top plate arranged to the top part of the central web (2) as well as a longitudinal lower flange (4) which is arranged to the bottom part of the central web (3) and which protrudes from the central web (2) to its both sides. The splice joint (5) comprises, on both outer sides of the central web (2), a plate-like tongue- and-groove joint (6) receiving its the shear forces, the tongue-and-groove joint (6) in each case comprising a tongue (7) fixed to the central web (2) of a main girder part (la) to be joined, and a groove (8) fixed to the central web (2) of a second main girder part (la) to be joined; and a lower flange joint (9) receiving the bending forces of the splice joint (5), whereby the tongue-and-groove joints (6) on opposite outer sides of the web (2) are arranged reversed in relation to each other, and whereby the location of the tongues and grooves (7, 8) on opposite sides of the web (2) is reverse in relation to each other.