摘要 |
PURPOSE:To attempt to improve the heat efficiency of a torpedo to resin flow and a resin in a gate part without changing the open angle of the gate part, by making the apex part of the torpedo faced to the gate part to be a sharp angle being 30 deg. or less. CONSTITUTION:A torpedo 14 running through a runner bush 11 from a nozzle 8a of a sprue part 12 to a gate 12 of a mold 4 is provided in a manifold 5 and this torpedo 14 has therein a built-in heater 15. The apex part of the torpedo facing to a funnel-shaped gate 12a of the gate part 12, namely, a gate chip part 14a is formed to be a sharp shape and the apex angle theta1 of the apex gate chip part 14a of this torpedo 14 is 30 deg. or less and it is formed to be a reverse conical shape. The open angle theta2 of the gate 12a of the mold 4 is formed to be 60 deg.-120 deg., which is the same as the conventional ones. |