| 摘要 |
PURPOSE:To obtain a plunger tip which is exerted with compressive stress in its longitudinal direction even at ordinary temperature or operating temperature and is long in service life by using the ceramics of the specific characteristic to the plunger tip of a cold chamber type die-casting machine. CONSTITUTION:With a plunger rod 7 as a guide, a ceramics-made plunger tip 5 is inserted slidably into a pouring sleeve 2. The ceramics comprises forming Al base alloy or the like of superior corrosion and abrasion resisrances to molten metal and small coefficinets of friction and thermal expansion, e. g., Si3N4/Al2O3 base or other. This is sandwiched by a plunger head 6 and plunger rod 7 and is fastened by way of packings 8, 9 such as of graphite films or the like by the female screw 6a of the former and male screw 7a of the latter. These are so constructed as not to directly cool the tip 5 as cooling water is supplied to a pipe 10 and returns from the inside hole 11 of the rod 7. |
