To restrain the rapid cooling of molten metal for supplying, to prevent the local solidification of the molten metal and to minimize the enclosure of gas generated with the thermal decomposition of lubricant by joining and integrating a two-layer structural cylinder which constitutes an outer casing member with a heat resistant metallic cylindrical body and the whole length or a partial range in the axial direction of an inner casing member with a porous cylindrical body.
The constitution of a plunger sleeve is joined and integrated to the two-layer structural cylinder 3 which arranged the porous cylindrical body 1 as the inner casing member over the whole length of the axial direction and laminating the heat resistant metallic cylindrical body 2 as the outer casing member on the outer periphery of the inner casing member. Further, a ceramic base porous cylindrical body 1A is applied to the rear side range portion of the inner casing member and a metal base porous cylindrical body 1B is applied to the front side range portion. Furthermore, at the one end part of a spiral groove 6 formed in the outer peripheral part of the porous cylindrical body 1, a lubricant press-in hole 7 is bored so as to penetrate the heat-resistant metallic cylindrical body 2. The lubricant is pressed into the spiral groove 6 from the lubricant press-in hole 7 with a lubricant press-in pump and impregnated into the porous cylindrical body 1.
UCHIMURA KATSUJI
MATSUI TETSUJI
Next Patent: VALVE DEVICE FOR GAS VENTING IN DIE FOR DIE CASTING