Robot Coupling Element with Pneumatic Compliance for Casting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current metallurgic robots lack the accuracy and dexterity to handle heavy, large, and deformable metal elements in casting processes, requiring human intervention that is hazardous and prone to errors due to the limitations of existing compliant coupling elements which fail to withstand high loads and temperatures.
Innovation Solution
A coupling element with a tool interface rigidly coupled to the handling tool and a robot interface, featuring an adjustable compliance mechanism with an inflatable chamber and anchor rods, allowing translation, rotation, and self-centering capabilities to compensate for misalignment and provide variable stiffness, enabling precise handling of metal elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid coupling element is used to connect the robot arm to the handling tool, then the structural strength and stability are improved, but the positioning precision and ability to compensate for misalignment deteriorate
Solution Approach 1:
The coupling element is divided into multiple functional segments: a rigid base component for structural strength, a compliant component with pneumatic chamber for positioning precision, and shoulder bolts for alignment. This segmentation allows each part to fulfill its specific function while working together as an integrated system.
Solution Approach 2:
The compliant component acts as an intermediary element between the rigid robot arm and the handling tool. It mediates the connection by providing both mechanical support and positional compliance, allowing the system to achieve both strength and precision through this intermediate compliant layer.
2Manufacturing precision
If a compliant coupling element is used to improve positioning precision and compensate for misalignment, then the positioning precision is improved, but the load-bearing capacity deteriorates
Solution Approach 1:
The coupling element employs a composite structure combining rigid materials (base component, shoulder bolts) for load-bearing with compliant materials (pneumatic chamber, elastic elements) for positioning precision. This composite design allows the system to simultaneously achieve high load-bearing capacity and fine positioning accuracy.
Solution Approach 2:
The compliant component incorporates a pneumatic chamber that can dynamically adjust its stiffness characteristics. By varying the pneumatic pressure, the coupling element can adapt its compliance level to match different operational requirements, providing both precision and strength as needed.
3Ease of operation
If springs are used to provide compliance and enable return to reset position, then the compliance and self-return capability are improved, but the reliability under high temperature and wear conditions deteriorates
Solution Approach 1:
The invention replaces mechanical springs with a pneumatic chamber for providing compliance and the self-return function. The pneumatic system is significantly more reliable than springs in high-temperature metallurgical environments, as pneumatic components do not suffer from thermal degradation or wear in the same way mechanical elastic elements do.
Solution Approach 2:
The patent substitutes the mechanical spring-based compliance mechanism with a pneumatic compliance mechanism. This replacement eliminates the wear and thermal degradation issues inherent in mechanical springs, thereby improving reliability while maintaining the desired compliance and self-return capabilities.
4Manufacturing precision
If shoulder bolts with conical surfaces are used to define reset position, then the transverse and rotational alignment are improved, but the compliance under tensile stress deteriorates
Solution Approach 1:
The coupling element implements different compliance characteristics in different directions and loading conditions. The shoulder bolts with conical surfaces provide precise alignment in transverse and rotational directions, while the pneumatic chamber provides compliance specifically under compressive loads. This local differentiation of mechanical properties allows the system to achieve both precision and adaptability.
Solution Approach 2:
The pneumatic chamber provides dynamic compliance that can adapt to different loading conditions. Under tensile stress, the system maintains alignment through the shoulder bolts, while under compressive stress, the pneumatic chamber provides the necessary compliance. This dynamic response to different stress states resolves the contradiction between alignment precision and compliance versatility.
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 solution enables precise handling and positioning of metal elements by allowing the handling tool to move relative to the robot arm, maintaining accuracy and safety while withstanding high loads, thus reducing human error and improving operational efficiency in metallurgic casting.
Implementation Method 1
The compliance of the coupling element is provided by a piston pushing against the base component and disposed in a chamber having a pneumatic port, and the compliance level can be changed by varying the pneumatic pressure in the chamber behind the piston.
Implementation Method 2
Springs are indeed inserted between the base component and and the compliance component so as to push the conical surfaces of the compliance component against the shoulder portion of the bolts fixed to the base component.
Data Source
AI summary
A metallurgic casting installation comprises a robot. The robot comprises a handling tool coupled to an arm of the robot by a coupling element. The coupling element comprises a tool interface rigidly coupled to the handling tool, and a robot interface rigidly coupled to the arm of the robot. The compliance of the coupling element can be controlled such that upon application of a load onto the tool interface, the tool interface can be moved relative to the robot interface, by translation along and/or rotation about one or more of a first, second and third orthogonal spatial axes X1, X2, X3. The coupling element is resilient in that upon release of the load, the tool interface returns to a reset position relative to the robot interface corresponding to a reset distance Dr separating the tool interface and the robot interface.