Flaskless Molding Method with Two-Stage Sand Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flaskless molding methods often result in molds with insufficient hardness due to inadequate molding sand charging, leading to inconsistent mold quality.
Innovation Solution
The method involves defining initial and increased molding spaces within cope and drag flasks using squeezing members, with sequential sand injections to achieve the desired mold hardness, and includes the option of core placement before mold stacking and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional single-stage sand charging is used, then the molding process is simple and fast, but the mold hardness is insufficient and quality is inconsistent
Solution Approach 1:
The sand charging process is divided into two distinct stages: initial sand charging to fill the mold cavity, and supplementary sand charging to add additional sand after the squeezing member retracts. This segmentation allows each stage to serve a specific purpose - the first stage establishes basic mold formation while the second stage ensures adequate sand volume and hardness, resolving the contradiction between simple process and high quality output.
Solution Approach 2:
The squeezing member is inserted to define a restricted molding space before sand charging, and then retracts after initial charging to create additional volume. This preliminary action of restricting and then expanding the molding space enables the two-stage sand charging process, ensuring that sand is properly distributed and compacted to achieve consistent mold hardness without overly complicating the overall process.
2Strength
If insufficient molding sand is charged, then the molding process is faster with less material, but the resulting molds lack desired hardness
Solution Approach 1:
The molding space volume is made dynamic through the retractable squeezing member. Initially, the squeezing member is inserted to create a restricted volume for efficient sand charging. After the first sand injection, the squeezing member retracts to increase the volume, allowing a second sand injection to add more sand. This dynamic volume adjustment ensures adequate sand quantity for hardness while optimizing the charging process efficiency.
Solution Approach 2:
The sand charging is performed in periodic cycles: first sand injection, squeezing member retraction, second sand injection, then squeezing member advancement for compaction. This periodic action pattern ensures that sufficient sand is delivered in controlled increments, achieving the desired mold hardness without requiring excessive sand volume in a single charging operation.
3Manufacturing precision
If the squeezing member is retracted to increase molding space volume, then more sand can be charged for better hardness, but the molding process time increases
Solution Approach 1:
The squeezing member retracts only by a predetermined, optimized length to increase volume just enough for the second sand injection, rather than fully retracting. This partial action provides sufficient additional volume for adequate sand charging while minimizing the time penalty. The retraction distance is carefully controlled to achieve the necessary sand volume for consistent hardness without excessive process time.
Solution Approach 2:
The two-stage sand charging process is integrated into a continuous molding cycle where the squeezing member's insertion, retraction, and advancement actions are seamlessly coordinated with the sand injection operations. The process maintains continuous useful action by ensuring that each movement of the squeezing member is immediately followed by the corresponding sand charging operation, minimizing idle time and maintaining production efficiency while achieving consistent mold hardness.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A flaskless molding method, wherein a match plate (5) is held between an upper flask (2) and a lower flask (3) and squeeze plates (6) and (7) are inserted into the openings of the upper flask (2) and the lower flask (3) to form an upper manufacturing space and a lower manufacturing space with initial volumes. A foundry sand is filled in the upper and lower manufacturing spaces with the initial volumes through the supply ports of the flask (2) and (3) (first filling). Next, the squeeze plates (6) and (7) are retreated to expand the upper and lower manufacturing spaces more than the initial volumes. The foundry sand is filled again in the expanded upper and lower manufacturing spaces through the supply ports (second filling). After the second filling is completed, the squeeze plates (6) and (7) are advanced to compress the foundry sand in the upper and lower manufacturing spaces so as to manufacture the upper and the lower flasks stacked on each other.