# US 2014/0191150 A1 · Poppet valve with a formed seat, and method of making

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- Number: US 2014/0191150 A1
- Document ID: US20140191150A1
- Status: Published application
- Kind: A1
- Application number: 14/208,822
- Filed: 2014-03-13
- Published: 2014-07-10
- Earliest claimed: 2012-06-14
- Assignees: Nittan Valve Co., Ltd.
- Applicants: Nittan Valve Co., Ltd.
- Inventors: Maiku MIKAMI; Kazunori KURAHASHI
- Web page: https://patentgrep.com/patent/US20140191150A1

## CPC

- F16K 1/42: Valve seats (for double-seat valves F16K1/44)
- B21K 1/22: poppet valves, e.g. for internal-combustion engines
- B23P 15/002: {poppet valves}
- F01L 3/00: Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
- F01L 3/04: Coated valve members or valve-seats
- F01L 2303/00: Manufacturing of components used in valve arrangements
- Y10T 137/0491: Valve or valve element assembling, disassembling, or replacing
- Y10T 137/0497: Fluid actuated or retarded
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}
- B21K: MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES, RIVETS, BOLTS OR WHEELS (making particular articles by working sheet metal without essentially removing material B21D; processing wire B21F; making pins, needles or nails B21G; making particular articles by rolling B21H; forging machines, pressing machines, hammering machines, in general B21J; making chains B21L; plating B23K)
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method of forming a poppet valve having a stem, a valve head and a valve seat while concurrently maintaining compressive residual stress without grain coarsening on both the valve body and the valve seat. The method includes forming a rounded cladded part on the valve head of the poppet valve by welding and forming a valve seat surface at a predetermined aperture angle and cutting the cladded part to form a smooth surface which is subjected to uniform contact pressure at a temperature less than the recrystallization temperature of the base material or cladding material, whichever is lower, to enhance the durability of the valve seat.

## Claims

### Claim 1

A method of forming a valve seat of a poppet valve comprised of a stem and a valve head formed at one end thereof, said method comprising:
forming a rounded cladded part on the valve head by welding; and
forming a valve seat surface having a predetermined aperture angle on the cladded part,
wherein the outer circumference of the valve head is cut into a predetermined dimension, the surface of the cladded part is cut to form a smooth surface thereon, and said smooth surface is forged by applying a uniform contact pressure at a temperature range possible for cold or warm forging while being less than the recrystallization temperature.

### Claim 2

A method of forming a valve seat of a poppet valve comprised of a stem and a valve head formed at one end thereof, said method comprising:
forming a rounded cladded part on the valve head by welding; and
forming a valve seat surface having a predetermined aperture angle on the cladded part,
wherein the surface of the cladded part is cut to form a smooth surface thereon, said smooth surface is applied plastic working, and
the plastic working is conducted by applying a uniform contact pressure at a temperature range possible for cold or warm forging while being less than the recrystallization temperature onto the region from the rounded cladded part to the inner circumference thereof to form a second smooth surface, in the same way as the first smooth surface is formed, said second smooth surface being integral with the first smooth surface to form an enlarged valve seat surface while having an aperture angle which is larger than the aperture angle of the first smooth surface.

### Claim 3

A poppet valve comprised of a stem and a valve head formed at one end thereof,
said valve head being provided with a rounded cladded part by welding so that a valve seat with a valve seat surface having a predetermined aperture angle is formed thereon, wherein
the outer circumference of the valve head being cut into a predetermined dimension, and
the surface of the cladded part being cut to form a smooth surface thereon to be forged by applying a uniform contact pressure at a temperature range possible for cold or warm forging while being less than the recrystallization temperature.

### Claim 4

A poppet valve comprised of a stem and a valve head formed at one end thereof,
said valve head being provided with a rounded cladded part by welding so that a valve seat with a valve seat surface having a predetermined aperture angle is formed thereon, wherein
the surface of the cladded part being cut to form a smooth surface thereon to be applied plastic working by applying a uniform contact pressure at a temperature range possible for cold or warm forging while being less than the recrystallization temperature onto the region from the rounded cladded part to the inner circumference thereof, so that a second smooth surface is formed in the same way as the first smooth surface is formed, said second smooth surface being integral with the first smooth surface to form an enlarged valve seat surface while having an aperture angle which is larger than the aperture angle of the first smooth surface.