Trw Limited

William Neumann

Victor D Levin

Rudy J Heimann, Jr

Roger R Wills

Mohan Kurup

Robert E Southam

Joseph L Palko

Robert J Colo

John C Kosco

A work-hardened poppet exhaust valve for internal combustion engines is obtained from a solutioned work-hardenable austenitic stainless steel coil or bar stock in which chromium is present in the range of 13%-25% by weight, nickel is present in the range of 4%-16% by weight, manganese is present in the range of 0.25%-8% by weight, copper is present in the range of 0.5%-7% by weight, the interstitial elements carbon plus nitrogen are present in a total amount less than 0.45% by nitrogen are present in a total amount less than 0.45% by weight, and at least one refractory metal selected from the group consisting of molybdenum, niobium, vanadium, tungsten and tantalum is present in the range of 1%-5% by weight. The coil or bar stock is extruded to a poppet valve preform configuration at a temperature in the range of room temperature to 1,000&deg; F., and at a true strain of more than 0.8. The parameters of extrusion provide said work-hardened poppet valve with a stem hardness more than R &equals;25.

Work hardened poppet exhaust valve

A first part of an engine valve (10) is centered on an axis (A) and comprises a hollow metal member (100) having an outwardly flared first end portion (102) and a second end portion (104). The hollow metal member (100) has a chamber (106) extending axially throughout the member. The chamber (106) is open at the first end portion (102). A second part of the engine valve (10) is centered on the axis (A) and comprises a metal piece (130) coaxial with the hollow metal member (100). The metal piece (130) has first and second ends (132 and 134). The first end (132) has a first weld connection to the second end portion (104) of the hollow metal member (100). The metal piece (130) has a solid cross-section portion between the first and second ends (132 and 134). The metal piece (130) has a circumferential groove (150) in the solid cross-section portion. A metal cap (160) has a periphery (166) and a second weld connection (172) at the periphery to the outwardly flared first end portion (104) of the hollow metal member (100). The cap (160) closes the chamber (106) of the hollow metal member (110) at the flared first end portion (104). An inner surface (162) of the cap (160) is conical in shape and tapers axially away from the hollow metal member (100) as the inner surface (162) extends from the periphery (166) toward the axis (A). The cap (160) has an outer surface (164) which is conical in shape and tapers axially away from the hollow metal member (100) as the outer surface (164)) extends from the periphery (166) toward the axis (A).

Engine valve and method for making the same

A poppet valve (10) has a disk-shaped head (12), an elongated stem (16), and a tapered neck (24) between the head (12) and the stem (16). The neck (24) has an outer surface (32) with an undulating circumferential contour. The undulating circumferential contour improves component strength and heat transfer efficiency, and may also influence valve rotation and inlet charge swirl.

Poppet valve with embossed neck structure

A poppet valve (10) includes an elongated valve stem (14) with first and second ends (22, 26). A valve head (12) is located at the first end (22) of the stem (14). A valve tip (24) is fixed to the second end (26) of the stem (14). The tip (24) is constructed as an axially compressed piece of steel wire (32).

Poppet valve and method of making the poppet valve

A method of making work-hardened poppet exhaust valves for internal combustion engines comprises the steps of: providing a solutioned work-hardenable austenitic stainless steel coil or bar stock in which chromium is present in the range of 13%-25% by weight, nickel is present in the range of 4%-16% by weight, manganese is present in the range of 0.25%-8% by weight, copper is present in the range of 0.5%-7% by weight, the interstitial elements carbon plus nitrogen are present in a total amount less than 0.45% by weight, and at least one refractory metal selected from the group consisting of molybdenum, niobium, vanadium, tungsten and tantalum is present in the range of 1%-5% by weight; extruding the coil stock to a poppet valve preform configuration at a speed in the range of 60 to 100 strokes per minute and at a temperature in the range of room temperature to 1,000.degree. F.; and heading the preform at the same speed while maintaining the head of the preform at a temperature in the range of room temperature to 2,200.degree.; the parameters of extrusion providing the work-hardened poppet valve with a stem hardness more than R.sub.c =25.

Process for making exhaust valves

A powder composition is suitable for making a valve seat insert having good machinability and high temperature wear resistance. The composition consists essentially of about 0.5%-5% nickel, about 1%-10% molybdenum, less than 0.1% copper, about 0.4%-1.2% carbon, the remainder being iron. The ratio of nickel to molybdenum is about 0.25:1 to 1:1. The nickel and molybdenum are preferably present as a blend of elemental nickel, elemental molybdenum, and a pre-alloyed powder in which nickel and molybdenum are pre-alloyed with iron.

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Lakewood, OH, United States of America

William Neumann