Method of producing a hollow poppet valve and an apparatus therefor
OwnerMinoru Noguchi, Hiroyuki Tsuchiyama +1inventors
InventorsMinoru Noguchi, Hiroyuki Tsuchiyama, Masami Yasujima
Life of this patent
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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.
Claims15
A method of producing a hollow poppet valve, the method comprising:
- forming material that has a blind hole which is open at an upper end;
- pressing the material in a shaping hole in a die strongly to allow the material to pass through a downward-tapered squeezing portion of the shaping hole to extrude the material into a smaller-diameter portion of the shaping hole;
- and
- moving a pin down to allow the lower end of the pin to invade into an upper end of the smaller portion of the shaping hole to allow the material to plastically flow through an annular gap between an outer circumferential surface of a lower end of the pin and an inner circumferential surface of the smaller-diameter portion of the shaping hole thereby molding a primary intermediate of the valve, the primary intermediate comprising a stem and a larger-diameter head at an upper end of the stem, the primary intermediate having a cavity that has an opening at an upper end of the head.
A method of producing a hollow poppet valve, the method comprising:
- pressing a cylindrical material disposed in a shaping hole in a die, with a pin strongly to deform the material plastically to move a lower end of the pin into the material to form a blind hole having an opening at a top along an axis of the material;
- pressing the material strongly to allow the material to pass through a squeezing hole which tapers downward of the shaping hole to exclude the material toward a smaller-diameter portion of the shaping hole;
- and
- allowing the material to plastically flow downward through an annular gap between an outer circumferential surface of a lower end of the pin and an inner circumferential surface of the smaller-diameter portion of the shaping hole to mold a primary intermediate which comprises a stem and a larger-diameter head at an upper end of the stem, the primary intermediate having a cavity that has an opening at an upper end.
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.
Dependencies are inferred from the claim text.