(1) Quantity restriction of mold module division
In order to ensure the assembly accuracy between the divided mold modules, it is necessary to restrict the division number of mold modules. In the actual molding process, enterprises usually reduce unnecessary mold blocks according to the structural characteristics of castings. Therefore, in the forming of Dieless composite mold, the division number of mold modules must be less than the maximum allowable division number of mold. This constraint can be expressed as the formula:
Where G1 (XI) is the quantity constraint of mold module division; Mn (XI) is the actual mold module division quantity of process scheme Xi; Mnmax is the maximum allowable number of mold blocks.
(2) Mold wall thickness constraint
The design of mold wall thickness needs to fully consider the heat storage capacity of the mold and the strength of the mold, so as to avoid casting defects such as insufficient pouring after liquid metal solidification, as well as irreparable damage such as cracking and sand collapse during transportation and pouring. The wall thickness of the mold shall be designed to be greater than the allowable minimum wall thickness. This constraint can be expressed as the formula:
Where G2 (XI) is the constraint of mold wall thickness; MT (XI) is the mold wall thickness of process scheme Xi; Fmin is the allowable minimum wall thickness.
(3) Mold forming time constraints
The forming time of the mold is related to the selection of the forming method of the mold, the size and wall thickness of the mold. Combined with the requirements of the enterprise for production efficiency in actual production, the forming time of the mold should be less than the maximum rated production time to ensure the value balance between input and output. This constraint can be expressed as the formula:
Where G3 (XI) is the constraint of mold forming time; St (XI) is the mold forming time of process scheme Xi; Stmax is the maximum rated mold production time.