Rocker Arm Assembly for Sand Core Fixing in Casting Molds
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Solution Overview
Problem
In semi-permanent mold casting processes, sand cores tend to move during the pouring of molten metal, leading to deviations in the dimensions of the cast component and potential core breakage, which complicates the casting process.
Innovation Solution
A rocker arm assembly is used to fix the sand core within the casting mold, comprising a first lever and a second lever connected such that the movement of the first lever translates into pressure exerted by the second lever on the core, effectively anchoring it in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If sand cores are used to create complex internal structures in cast components, then the manufacturing capability for complex geometries is improved, but core flotation and movement occur during molten metal pouring, leading to dimensional deviations and potential core breakage
Solution Approach 1:
The patent applies preliminary action by pre-positioning support structures (such as chaplets or core anchors) into the mold cavity before pouring the molten metal. These supports are strategically placed to hold the sand core in its correct position, preventing core flotation and movement during the casting process, thereby maintaining dimensional accuracy while enabling complex internal structures
2Reliability
If chaplets are used to anchor the core in place, then core stability is improved, but the metallurgical process becomes complex and casting defects may be introduced
Solution Approach 1:
The patent extracts the core support function from the molten metal chaplet system and implements it through separate, pre-positioned support structures that are mechanically simple and do not require complex metallurgical processes. This separation allows the core to be anchored reliably while avoiding the introduction of chaplet metal into the casting, thereby reducing process complexity and eliminating associated casting defects
3Manufacturing precision
If the core is firmly anchored to prevent movement, then manufacturing precision is improved, but the complexity of the molding process increases
Solution Approach 1:
The patent applies segmentation by dividing the mold assembly into distinct functional components: the mold cavity, the sand core, and separate pre-positioned support structures. This segmentation allows each component to be optimized independently - the supports are simple mechanical elements that can be easily positioned and removed, providing firm core anchorage without complicating the overall molding process
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 rocker arm assembly significantly reduces core movement and prevents core breakage, ensuring that the cast component maintains precise internal dimensions and facilitating a more reliable and efficient casting process.
Implementation Method 1
a second lever (24) that is set up to exert pressure on the (sand) core (6), wherein the second lever (24) is connected to the first lever (22) via a connection (26) such that movement of the first lever (22), in particular a rotation of the first lever (22), in a first direction (P1), leads to transmission of force to the second lever (24) to exert pressure on the core (6)
Data Source
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AI summary
The invention relates to a rocker arm assembly (2) for fixing a core (6), in particular a sand core, inside a casting mold (4), comprising: a first lever (22), and a second lever (24) that is set up to exert pressure on the core (6). The invention also relates to a use of a rocker arm assembly, to a casting mold comprising at least one rocker arm assembly and a casting process using a casting mold with at least one rocker arm assembly.