Weight-Optimized Articulated Boom with Closed Indented Wall Elements
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Solution Overview
Problem
Large manipulators face weight limitations due to dead weight, and existing weight reduction methods, such as open framework structures, lead to dirt and water ingress, rust issues, and increased weight, compromising strength and stability.
Innovation Solution
The use of wall elements with indentations that are closed on the inside, forming a framework-like structure with webs and compartment surfaces of reduced material thickness, providing protection against water and dirt while maintaining stability and allowing for significant weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If open framework structures are used on mast segments to reduce weight, then weight is reduced, but dirt and water can penetrate and build up on the surface, leading to rust and increased weight
Solution Approach 1:
The patent applies a closed shell structure (the mast segment wall) that encloses the internal framework, creating a protective barrier against dirt and water while maintaining the weight-reducing framework design. The wall acts as a thin film shell that seals the structure.
Solution Approach 2:
The mast segment is divided into a framework structure with discrete members connected by joints, allowing weight reduction through selective material placement while maintaining structural integrity. The framework is segmented into load-bearing elements and non-load-bearing spaces.
2Stability of the object's composition
If sheet metal of different thicknesses is used to reduce load moment, then structural efficiency is improved, but a large number of butt joints or welded connections are required, increasing production complexity
Solution Approach 1:
The patent applies varying material thicknesses at specific locations within the mast segment - thicker material where structural strength is needed and thinner material where less strength is required. This localized quality variation optimizes the load moment while reducing the need for complex joints.
Solution Approach 2:
The mast segment combines different material thicknesses in a single integrated structure, creating a composite construction that optimizes both weight and strength. The framework members may also combine different materials to achieve optimal structural properties.
3Ease of manufacture
If greater material thicknesses are provided at the mast tip to ensure weldability, then weldability is maintained, but weight increases unnecessarily from a static point of view
Solution Approach 1:
The patent provides greater material thicknesses only in specific areas of the mast tip where weldability and structural strength are critical, while using thinner materials in other areas where less strength is required. This localized thickening maintains manufacturability without unnecessarily increasing overall weight.
Solution Approach 2:
The patent varies the material thickness parameter along the length of the mast segment, particularly at the mast tip, to optimize both weldability and weight. By changing this physical parameter locally, the design achieves manufacturability without excessive weight gain.
Data Source
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AI summary
Large manipulator (1) with a fold-out articulated boom (2) which has a turret (4) which can be rotated about a vertical axis (3) and a plurality of boom segments (5, 5a, 5b, 5c), wherein the boom segments (5, 5a, 5b, 5c) are pivotable at articulation joints (6, 6a, 6b, 6c) about respective articulation axes with respect to an adjacent boom segment (5, 5a, 5b, 5c) or to the turret (4), wherein at least one boom segment (5, 5a, 5b, 5c) is formed by a hollow structure (7) made up of interconnected wall elements (8, 8a, 8b, 8c). It is an object of the invention to reduce the weight of such a large manipulator. For this purpose, the invention proposes that a depression (11) is incorporated in at least one of the wall elements (8, 8a, 8b, 8c), wherein the depth of the depression is less than the material thickness of the wall element (8, 8a, 8b, 8c) such that the wall element (8, 8a, 8b, 8c) is closed in the region of the depression (11).