Pour Formulas

The sand casting subprocess Pour relies on the formulas below.

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time is the product of the following:

• Process time (see formula below)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.

Process time = Pour Time per Mold / Number of Cavities

Process time includes the time to pour metal into the crucible, move the crucible, and then pour into the mold. It is the product of the following:

• Pour time per mold (see formula below)

• Number of cavities (see Number of Mold Cavities)

Pour Time Per Mold = Material Coefficient * Sqrt(Pounds Poured Per Cavity * Number of Cavities) +

Ladle Transport Time + Furnace Tap Time

Mold pour time is a function of the following:

• Material coefficient. Looked up by material type in the lookup table tblPouringCoefficients. If the part’s average thickness and weight are not within the ranges handled by the lookup table, a value of 1 is used for the coefficient. Similarly, if the part’s material is not handled by the lookup table, a value of 1 is used for the coefficient.

• Pounds poured per cavity. This is the Mass Poured as calculated for the Melting process (see Melting Formulas for Sand Casting) converted to pounds. Note that this quantity is the number of pounds poured. The formula implicitly converts this quantity to an equal number of seconds, so that the formula as a whole results in a number of seconds.

• Number of cavities (see Number of Mold Cavities)

• Ladle transport time. By default this is the value of the plant variable defaultLadleTransportTime (1 minute in starting point VPEs). Users can override the default with the PSO Ladle Transfer Time—see Pour Setup Options.

• Furnace tap time (see formula below)

Furnace Tap Time = Mass Poured Per Cavity * Number of Cavities / Furnace Tap Rate

Furnace tap time depends on the following:

• Mass poured per cavity. This is the Mass Poured as calculated for the Melting process (see Melting Formulas for Sand Casting).

• Number of cavities (see Number of Mold Cavities)

• Furnace tap rate (specified by the cost model variable furnaceTapRate---121 kg/sec in starting point VPEs)