CN-122007350-A - Device and method for predicting occurrence position of shrinkage cavity of casting

CN122007350ACN 122007350 ACN122007350 ACN 122007350ACN-122007350-A

Abstract

The invention provides a device and a method for predicting occurrence position of shrinkage cavity of a casting, which can increase options of shrinkage cavity countermeasures of the casting. The invention relates to a device for predicting the occurrence position of shrinkage cavity of a casting cast by injecting molten metal into a casting mold, which comprises a measuring point setting part for setting a plurality of measuring points for the casting, a molten metal replenishment limit solid phase arrival time calculation part for calculating the molten metal replenishment limit solid phase arrival time for each measuring point, a solidification path setting part connected with the measuring points selected based on the molten metal replenishment limit solid phase arrival time to set the solidification path of the casting, a surface distance calculation part for calculating the distance from the measuring point to the surface of the nearest casting for each measuring point positioned on the solidification path, and a molten metal replenishment blocking part determination part for determining the molten metal replenishment blocking part for blocking the molten metal replenishment during the solidification of the molten metal.

Inventors

Cheng Cheng Shi
AMANO NORIHIRO

Assignees

丰田自动车株式会社

Dates

Publication Date: 20260512
Application Date: 20251107
Priority Date: 20241112

Claims (2)

1. An apparatus for predicting a position of occurrence of shrinkage cavity of a casting cast by injecting molten metal into a mold, comprising: a measurement point setting unit that sets a plurality of measurement points for the casting; A molten metal replenishment limit solid phase rate arrival time calculation unit that calculates, for each of the measurement points, a molten metal replenishment limit solid phase rate arrival time which is a time until a solid phase rate at which molten metal cannot flow is reached; a solidification path setting unit that sets a solidification path of the casting by connecting the measurement points selected based on the molten metal replenishment limit solid fraction reaching time; A surface distance calculating section for calculating, for each of the measurement points located on the solidification path, a distance from the measurement point to a surface of a nearest casting, and A molten metal supply blocking portion determining portion that determines a molten metal supply blocking portion that blocks the molten metal supply during solidification of the molten metal, based on a distance to a surface of the casting.
2. A method for predicting the occurrence position of shrinkage cavities in a casting cast by injecting molten metal into a mold, comprising: Setting a plurality of measurement points for the casting; calculating a time until the solid fraction at which the molten metal cannot flow reaches the maximum solid fraction arrival time of the molten metal replenishment for each of the measurement points; A step of setting a solidification path of the casting by connecting the measurement points selected based on the arrival time of the molten metal replenishment limit solid fraction; a step of calculating, for each measurement point on the solidification path, a distance from the measurement point to a surface of a nearest casting, and Determining a molten metal supply blocking portion that blocks the molten metal supply during solidification of the molten metal based on a distance to a surface of the casting.

Description

Device and method for predicting occurrence position of shrinkage cavity of casting Technical Field The invention relates to a device and a method for predicting occurrence positions of shrinkage cavities of castings. Background Patent document 1 discloses a method for predicting a position of occurrence of shrinkage cavity in a casting produced by injecting molten metal into a mold, wherein a radius value of a virtual inscribed sphere is obtained for each internal point in the casting, and then a range of internal points having a radius value larger than a reference radius value is obtained, thereby specifying a portion where shrinkage cavity is likely to occur. Patent document 1 Japanese patent application laid-open No. 2021-53662 Disclosure of Invention As a countermeasure for a portion where shrinkage cavity is likely to occur, thinning may be considered, but depending on the performance and the like required for the casting, there may be considered a case where thinning is impossible. Therefore, various options are required for countermeasures for the portion where shrinkage cavity is easily generated. The present invention is to solve the above problems and to provide a device and a method for predicting a position of occurrence of shrinkage cavity in a casting, which can increase options for countermeasure against shrinkage cavity in the casting. The present invention provides an apparatus for predicting the occurrence of shrinkage cavity in a cast by injecting molten metal into a mold, comprising a measurement point setting unit for setting a plurality of measurement points for the cast, a molten metal replenishment limit solid phase arrival time calculation unit for calculating, for each of the measurement points, a molten metal replenishment limit solid phase arrival time which is a time until a solid phase at which molten metal cannot flow, a solidification path setting unit for setting a solidification path of the cast by connecting the measurement points selected based on the molten metal replenishment limit solid phase arrival time, a surface distance calculation unit for calculating, for each of the measurement points located on the solidification path, a distance from the measurement point to a surface of the nearest cast, and a molten metal replenishment blocking position determination unit for determining a molten metal replenishment blocking position for blocking molten metal replenishment during solidification of molten metal based on the distance to the surface of the cast. With this structure, the options for the shrinkage cavity countermeasure of the casting can be increased. A method for predicting the occurrence of shrinkage cavity in a cast by injecting molten metal into a mold, comprising a step of setting a plurality of measurement points for the cast, a step of calculating a molten metal replenishment limit solid phase arrival time, which is the time until the solid phase at which molten metal cannot flow, for each of the measurement points, a step of setting a solidification path of the cast by connecting the measurement points selected based on the molten metal replenishment limit solid phase arrival time, a step of calculating the distance from the measurement point to the surface of the nearest cast for each of the measurement points on the solidification path, and a step of determining a molten metal replenishment interruption point for interrupting molten metal replenishment during solidification of molten metal based on the distance to the surface of the cast. With this structure, the options for the shrinkage cavity countermeasure of the casting can be increased. Effects of the invention The present invention can provide a device and a method for predicting a position of occurrence of shrinkage cavity in a casting, which can increase options for countermeasures against shrinkage cavity in the casting. Drawings Fig. 1 is a perspective cross-sectional view of a cylinder head for predicting a position of occurrence of shrinkage cavity. Fig. 2 is a partial cross-sectional view seen from the direction indicated by II of the cylinder head shown in fig. 1. Fig. 3 is a block diagram showing a shrinkage cavity occurrence position prediction device according to the embodiment. Fig. 4 is an explanatory diagram of a method for predicting a generation position of a shrinkage cavity according to the embodiment. Fig. (a) shows a state in which molten metal is being filled into a cavity. Fig. (b) shows a state in which the filling of the cavity with molten metal is completed. Fig. (c) shows a state where the molten metal starts to solidify. Fig. (d) shows a state in which interruption of molten metal supply occurs as solidification of molten metal proceeds. Fig. 5 is a flowchart showing an example of a method for predicting the occurrence position of a shrinkage cavity according to the embodiment. Fig. 6 is a diagram showing an example of the molten metal replenishment limit solid fract