Casting Mold Chill Core for Engine Block Cooling
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Solution Overview
Problem
Casting molds for engine blocks, particularly those made from light metal or light metal alloys, face challenges with high stress concentrations at the transition between formed spaces and mounting surfaces, leading to cracking and fractures due to uneven cooling and solidification processes, which are difficult to manage with existing methods that require preheating and specific structural designs.
Innovation Solution
A casting mold design where the casting core is divided into sections, with a chill mold having high thermal conductivity and molding sand, allowing for targeted, accelerated cooling in specific areas, eliminating the need for preheating and ensuring optimal material properties by controlling heat extraction and solidification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the mold is made from metal with high thermal conductivity to achieve accelerated cooling and improved material structure, then the mechanical and thermal resilience of the cast material is improved, but the risk of rapid solidification causing cracks or material fractures increases
Solution Approach 1:
The invention applies local quality by using a chill mold only in the specific region where improved mechanical and thermal resilience is needed (the region subject to high operational loads), while other parts of the mold remain made of molding sand. This localized application of high thermal conductivity material achieves the desired material structure improvement without subjecting the entire casting to rapid cooling that would cause cracks.
Solution Approach 2:
The chill mold is pre-positioned in the mold cavity before pouring the molten metal. This preliminary placement ensures that when the molten metal contacts the chill mold, the cooling action is immediately controlled and localized, preventing uncontrolled rapid solidification that would lead to cracking while still achieving the desired accelerated cooling in the target region.
2Reliability
If preheating of metal molds is performed to prevent rapid solidification and cracking, then the reliability of the casting process is improved, but the manufacturing cost and process complexity increase
Solution Approach 1:
Instead of preheating the mold to prevent rapid solidification (the conventional approach), the invention inverts the approach by using a material (molding sand) that naturally provides thermal insulation, thereby eliminating the need for preheating while still preventing uncontrolled rapid solidification and cracking.
Solution Approach 2:
The invention replaces expensive, complex preheating equipment and processes with a simple, inexpensive chill mold made of metal that is inserted into the mold cavity. This simple component achieves the desired effect without requiring costly preheating infrastructure or complex process control.
3Adaptability or versatility
If the casting core is divided into sections with different materials (chill mold and molding sand), then targeted cooling control is improved, but the device complexity increases
Solution Approach 1:
The casting core is segmented into two distinct sections: a chill mold section made of metal with high thermal conductivity for targeted accelerated cooling, and a molding sand section for general mold formation and thermal insulation. This segmentation allows independent optimization of each section's function, achieving precise thermal control while keeping the overall structure relatively simple.
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
This design enables cost-effective production of engine blocks with locally resilient structures, particularly in areas like the cylinder chamber, effectively preventing material failure and ensuring the cast parts can withstand operational stresses without preheating the molds, enhancing the mechanical and thermal properties of the cast material.
Implementation Method 1
The section made from a chill mold has a much higher thermal conductivity than the molding sand from which the remaining portion of the casting core is made, so that locally limited, accelerated cooling takes place in the area of the casting mold in which the melt poured into the casting mold comes into contact with the chill mold
Implementation Method 2
The aluminum solidifies faster on the surface of the brass mold than on the surface of the sand mold due to the higher thermal conductivity of the metal in the mold
Data Source
AI summary
The present invention relates to a casting mould for casting a cast part, in particular an engine block for an internal combustion engine, and the use of such a casting mould which is made up of mould parts 1, 2, 3, produced from moulding sand, and casting cores 4, 5, 6, 7, and has at least one casting core 4, 5, 6, 7 for forming a space in the cast part. The casting mould according to the invention makes it possible in a simple way to produce cast parts in which at least one locally confined portion is formed with a different microstructure than the rest of the cast part. This is achieved by a portion of the casting core 4, 5, 6, 7 being formed by a chill 9, which is made from a material of a thermal conductivity that is many times greater than the thermal conductivity of the remaining portion 8 of the casting core 4, 5, 6, 7, consisting of moulding sand.