Fluid-conducting hot-forging die and method of making the same

Claim 1

A fluid-conducting porous hot-forging die device, comprising a die holder having a bore therein, a porous die body composed of particles of sintered powdered heat-treated tool steel and having a die cavity therein and an outer peripheral surface therearound spaced outward from said die cavity and spaced inward from said die holder bore and defining therewith a fluid chamber, means for supplying a lubricant fluid under high pressure to said chamber, fluid-conducting means in said porous die body consisting of a multiplicity of minute fluid-transmissible passageways formed by the pores between said particles and extending continuously from said fluid chamber outside said outer peripheral surface to said die cavity with their opposite ends open to said chamber outside said outer peripheral surface and to said die cavity respectively, said die cavity having an elongated substantially cylindrical upper cavity portion, a substantially cylindrical lower cavity portion of smaller diameter than said upper cavity portion, and a taperEd intermediate cavity portion connecting said upper and lower cavity portions and merging smoothly at its junctions with said upper and lower cavity portions, and an elongated power-operated substantially cylindrical punch of substantially the same diameter as said upper cavity portion reciprocably movable into and out of closely-fitting but relatively-sliding telescoping relationship with said elongated cylindrical upper cavity portion.