Double-Walled Boom Segment With Stiffening Boxes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Long articulated masts in mobile truck-mounted concrete pumps face challenges in achieving increased reach without compromising torsional rigidity and adhering to weight limits, particularly due to the weakening effect of immersion areas for hydraulic cylinders.
Innovation Solution
The incorporation of laterally spaced stiffening boxes formed by web plates and reinforcement plates, which enhance torsional rigidity without significantly increasing weight, and the extension of these stiffening boxes along the mast segment, especially around the hydraulic cylinder immersion areas and articulated joints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the sheet thickness is increased in the immersion areas of hydraulic cylinders, then the torsional rigidity is improved, but the weight increases
Solution Approach 1:
The patent applies local quality by providing reinforcement plates only in specific immersion areas where hydraulic cylinders penetrate the mast segment, rather than uniformly thickening the entire structure. The reinforcement plates are strategically positioned at locations experiencing highest stress concentrations, allowing localized strengthening without global weight increase.
Solution Approach 2:
The mast segment is divided into distinct functional zones: reinforced immersion areas with reinforcement plates, and non-reinforced areas with standard wall thickness. This segmentation allows the structure to have varying thickness profiles optimized for different functional requirements, maintaining torsional rigidity where needed while minimizing weight elsewhere.
2Length of moving object
If the mast length is increased to achieve greater reach, then the outreach is improved, but the torsional rigidity decreases
Solution Approach 1:
Reinforcement plates are applied selectively at critical immersion areas along the mast segment, providing localized torsional reinforcement that compensates for the overall reduction in rigidity caused by increased mast length. This allows longer masts to maintain sufficient rigidity at stress-critical locations without uniformly increasing the entire structure's weight.
3Strength
If the wall thickness is increased to improve torsional rigidity, then the strength is improved, but the weight increases
Solution Approach 1:
Instead of uniformly increasing wall thickness throughout the mast segment, the patent uses reinforcement plates only at specific immersion areas where hydraulic cylinders are mounted. This localized approach provides the necessary torsional reinforcement at stress-critical locations while maintaining standard wall thickness in non-critical areas, thereby minimizing weight increase.
4Strength
If the mast segment is strengthened to increase torsional rigidity, then the structural integrity is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The reinforcement structure is segmented into discrete reinforcement plates that can be manufactured separately and then attached to the mast segment. This modular approach simplifies manufacturing compared to creating a monolithic thick-walled structure, as the reinforcement plates can be produced using standard sheet metal fabrication processes and joined using conventional welding or fastening methods.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a boom segment (1) having a top flange (2), a bottom flange (3) and two lateral web plates (4, 5), wherein the web plates (4, 5), together with the top flange (2), the bottom flange (3) and reinforcement plates (7, 8) spaced laterally from the web plates (4, 5), each form strengthening boxes (9, 10) located laterally on the boom. The invention further relates to an articulated boom (50) having a boom segment (1) of this kind and to a large manipulator (100) having an articulated boom (50) of this kind.