Suction Pressure Casting Decompression Pattern Correction
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Solution Overview
Problem
In suction pressure casting, the conventional method struggles to real-time feedback-control the exhaust valve based on cavity pressure, leading to misruns or gas defects due to variations in core moisture and binder state, which differ by production lot and storage conditions.
Innovation Solution
A suction pressure casting method that measures cavity and core pressures during casting, calculates a corrected decompression pattern by comparing preset and actual patterns, and updates the decompression pattern for subsequent castings to align with the actual gas generation, thereby minimizing misruns and gas defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a preset decompression pattern is used to control the exhaust valve, then the casting process can be carried out with a simple control system, but the system cannot adapt to variations in core moisture and binder state, leading to misruns or gas defects
Solution Approach 1:
The patent implements feedback control by measuring the actual cavity pressure during casting, comparing it with the preset decompression pattern, and using the deviation information to correct the exhaust valve control for subsequent castings. This feedback mechanism enables the system to adapt to core variations while maintaining a relatively simple control structure.
Solution Approach 2:
The system changes the decompression pattern parameters (exhaust valve opening amount and timing) based on measured pressure deviations from previous castings. By dynamically adjusting these parameters in response to actual casting conditions, the system adapts to variations in core moisture and binder state without requiring complex real-time control.
2Adaptability or versatility
If real-time feedback control of the exhaust valve is implemented, then the system can adapt to core variations, but the response delay of the exhaust valve prevents effective real-time control
Solution Approach 1:
The system performs preliminary measurement of the decompression pattern during each casting, then uses this measured data to pre-correct the exhaust valve control parameters for the next casting. This preliminary action approach allows the system to adapt to core variations without requiring fast real-time valve response during the actual pouring process.
Solution Approach 2:
The system uses the measured pressure data from each casting to automatically adjust and improve its own control parameters for subsequent operations. This self-service mechanism enables continuous adaptation to core variations without external intervention, effectively compensating for the valve's response delay through iterative learning.
3Speed
If the exhaust valve opening amount is adjusted using a vacuum tank and exhaust valve, then responsiveness is improved compared to exhaust pumps, but delay still occurs during short pouring times
Solution Approach 1:
The patent uses feedback from pressure measurements to compensate for the valve response delay. By measuring the actual decompression pattern and comparing it with the ideal pattern, the system calculates correction amounts that account for the inherent delay, thereby improving the effective responsiveness of the exhaust control.
4Reliability
If a preset decompression pattern is used, then the control is simple, but the difference between preset and ideal decompression patterns causes misruns or gas defects
Solution Approach 1:
The patent implements feedback control by measuring the actual cavity pressure during casting, comparing it with the preset decompression pattern, and using the deviation information to correct the exhaust valve control for subsequent castings. This feedback mechanism enables the system to adapt to core variations while maintaining a relatively simple control structure.
Solution Approach 2:
The system changes the decompression pattern parameters (exhaust valve opening amount and timing) based on measured pressure deviations from previous castings. By dynamically adjusting these parameters in response to actual casting conditions, the system adapts to variations in core moisture and binder state without requiring complex real-time control.
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 approach effectively reduces the difference between preset and ideal decompression patterns, preventing misruns and gas defects by dynamically adjusting the exhaust valve control based on measured core conditions, ensuring consistent casting quality.
Implementation Method 1
a suction-exhaust means (8) for suctioning and exhausting the inside of the cavity (5)
Implementation Method 2
a molten-metal pressurizing means (7) for supplying pressurizing gas into the holding furnace (3)
Data Source
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AI summary
A suction pressure casting method according to the present invention includes: with use of a casting device 1 that is provided with a holding furnace 3 in which molten metal 2 is accumulated, a metal mold 6 that forms a cavity 5 together with a core 4, a molten-metal pressurizing means 7 that supplies pressurizing gas, and a suction-exhaust means 8 that suctions and exhausts the inside of the cavity 5, a preset decompression pattern that is set in advance according to a casting process is compared with a measured pressure pattern of the cavity and the core that is measured during actual casting, a corrected decompression pattern is calculated based on the difference therebetween, and the preset decompression pattern at the time of the next casting is corrected by using the corrected decompression pattern; even if the amount of water in the core and the hardened state using a binder are different, the occurrence of a misrun or gas defect is suppressed.