| 摘要 |
PURPOSE:To remove a riser by gas cutting in short time with good operability by providing a core consisting of a heat insulating material in the neck part of the riser so that the tip of of a torch for gas cutting can be inserted thereto. CONSTITUTION:A core 10 consisting of a heat insulating material is formed to have the thickness T1 enough for the tip of a torch for gas cutting to be inserted between the riser 1 and a casting body 2. Even if the thickness T1 is made 1.5-2.5 times the thickness of the conventional sand mold core, feeding of the molten metal from the riser 1 to the body 2 is thoroughly accomplished by making the diameter N in the neck part of the core 10 the same as in the prior art. The casting surface is improved if a sand mold 12 is adhered to the body 2 side of the core 10 and a mold coating material is applied thereto. The operation of removing the riser from the body 2 is executed economically in short time by the above-mentioned method. |
