Apparatus for producing a hollow poppet valve

Abstract

A method of producing a hollow valve comprises the step for forming material having a blind hole along its axis, the step for extruding the material in a shaping hole in a die downward and the step for lowering a lower part of a pin to an upper part of a smaller-diameter portion of the shaping hole to allow the material to plastically flow downward through a gap between the lower part of a pin and the smaller-diameter portion of the shaping hole thereby molding a primary intermediate of the hollow valve having a stem and a head at the upper end of the stem through which a hole is formed.

1 - 11 . (canceled) 
     
     
         12 . An apparatus for producing a hollow poppet valve, the apparatus comprising a first press that comprises:
 a die having a shaping hole that comprises a larger-diameter portion into which material can be inserted, a squeezing portion which communicates with the larger-diameter portion and tapers downward, and a smaller-diameter portion which communicates with the squeezing portion to form a stem of the poppet valve;   a ram that rises and lowers above the die;   a punch attached to the ram, a lower end of the punch being capable of moving into the larger diameter portion of the shaping hole in the die; and   a pin disposed to move up and down in a vertical guide hole along an axis of the punch and connected to the ram, a smallest portion at a lower end projecting from the punch downward to put into the smaller-diameter portion of the shaping hole.   
     
     
         13 . The apparatus of  claim 12 , further comprising pressing means for forcing the punch downward to press the primary intermediate downward until the pin moves up. 
     
     
         14 . The apparatus of  claim 13 , wherein the pressing means comprise a compression spring. 
     
     
         15 . The apparatus of  claim 12 , further comprising a second press disposed near the first press, the second press comprising:
 a die holder;   a ram above the die holder to rise and lower;   a die in a recess in the die holder having a shaping hole; and   a punch in a recess in the ram and having a projection at a lower end, the head of the primary intermediate being forged and molded between the projection of the punch and the shaping hole of the die by the second press to form a head of the secondary intermediate of the hollow poppet valve.