抄録
Gating systems commonly used for automobile castings are mainly composed of linear runners, such as L-shaped or reverse T-shaped runners. A stuby has been made on the amount of flow through multi-ingates in these gating systems using Bernoulli’s theorem.
When the gaing systems can be considered to be filled with molten metal, the amount of flow through each gate can be calculated from the theory that the sum of losses, including the loss by friction, the loss at bending, the loss due to the cross sectional area change and the velocity heads of metal flow through gates, will be equal to the energy determined by the height of the sprue.
The loss coefficients of bending and choking were obtained by measuring the pressure loss of water flow poured into a plastic tube. These loss coefficients can be used as the loss coefficients of the flow in calculating the amount of flow of molten metal.
The loss coefficient of bending at the sprue bottom and that on the horizontal plane take the values of 1 to 4 and 1 to 2.5, respectively. The loss coefficient at 50% stepwise areal reduction takes the value of 0.2.
