# US 10,480,399 B2 · Structure and method for joining nozzle vane and lever, and variable geometry turbocharger

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- Number: US 10,480,399 B2
- Document ID: US10480399B2
- Status: Granted
- Kind: B2
- Application number: 15/039,278
- Filed: 2013-12-16
- Published: 2017-01-26
- Granted: 2019-11-19
- Earliest claimed: 2013-12-16
- Assignees: Mitsubishi Heavy Industries Engine & Turbocharger, Ltd.
- Applicants: Mitsubishi Heavy Industries Engine & Turbocharger, Ltd.
- Inventors: Takashi Arai; Hitomi Otsubo
- Web page: https://patentgrep.com/patent/US10480399B2

## CPC

- F02B 37/24: by using pumps or turbines with adjustable guide vanes
- B23K 15/0053: {Seam welding}
- B23K 15/0093: {characterised by the properties of the materials to be welded}
- B23K 26/28: of curved planar seams
- B23K 26/323: involving parts made of dissimilar metallic material
- B23K 31/003: {relating to controlling of welding distortion}
- F01D 5/04: for radial-flow machines or engines
- F01D 9/02: Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)}
- F01D 17/16: by means of nozzle vanes
- F02B 33/40: of non-positive-displacement type
- F02B 39/00: Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00
- F02C 6/12: Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
- B23K 2101/001: {Turbines}
- B23K 2103/05: {Stainless steel}
- B23K 2103/18: Dissimilar materials
- B23K 2103/26: {Alloys of Nickel and Cobalt and Chromium}
- F01D 17/165: {for radial flow, i.e. the vanes turning around axes which are essentially parallel to the rotor centre line (F01D17/167 takes precedence)}
- F05D 2220/40: in turbochargers
- F05D 2230/232: by welding
- F05D 2300/177: Ni - Si alloys
- Y02T 10/12: Improving ICE efficiencies
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An object is to provide a structure and a method of joining a nozzle vane and a lever, and a variable geometry turbocharger, capable of reducing breakage of a welded part between a shaft portion of the nozzle vane and the lever during usage of the same by reducing generation of a hot crack in weld metal at the welded part. A joint structure includes: a nozzle vane 2 disposed in an exhaust passage for guiding exhaust gas to a turbine wheel 34 of a variable geometry turbocharger 500, and including a shaft portion 2a; and a lever 1 including a fitting surface 42a fitted with a peripheral surface 72 on one end side of the shaft portion, for transmitting torque to the shaft portion to adjust a vane angle of the nozzle vane. Weld metal 50 at a welded part 40 between the lever and the nozzle vane is formed so that a center position 64 of the weld metal is disposed inside a position 17 of the fitting surface with respect to a radial direction of the shaft portion.

## Claims

### Claim 1

A joint structure of a nozzle vane and a lever, comprising:
a nozzle vane to be disposed in an exhaust passage for guiding exhaust gas to a turbine wheel of a variable geometry turbocharger, the nozzle vane including a shaft portion; and
a lever including a fitting surface to be fitted with a peripheral surface on one end side of the shaft portion, for transmitting torque to the shaft portion to adjust a vane angle of the nozzle vane,
wherein the lever and the one end side of the shaft portion are joined to each other by welding, and
wherein weld metal at a welded part between the lever and the one end side of the shaft portion is formed so that a center position of the weld metal is disposed inside a position of the fitting surface with respect to a radial direction of the shaft portion, and
wherein the lever includes
a first contact surface formed to extend inward in the radial direction of the shaft portion from a first end of the fitting surface with respect to the axial direction of the shaft portion, and to contact the shaft portion from the axial direction of the shaft portion, and
a second contact surface formed to extend outward in the radial direction of the shaft portion from a second end of the fitting surface with respect to the axial direction of the shaft portion, and to contact the shaft portion from the axial direction of the shaft portion.

### Claim 2 (depends on 1)

The joint structure of a nozzle vane and a lever, according to claim 1,
wherein an outer position of the weld metal is formed inside the fitting surface with respect to the radial direction of the shaft portion.

### Claim 3 (depends on 1)

The joint structure of a nozzle vane and a lever, according to claim 1,
wherein the variable geometry turbocharger is for a gasoline engine, and
wherein the nozzle vane is composed of nickel-based alloy, and the lever is composed of stainless steel.

### Claim 4 (depends on 1)

A variable geometry turbocharger, comprising:
the joint structure of a nozzle vane and a lever according to claim 1;
the turbine wheel; and
a compressor driven by the turbine wheel.

### Claim 5

A joint structure of a nozzle vane and a lever, comprising:
a nozzle vane to be disposed in an exhaust passage for guiding exhaust gas to a turbine wheel of a variable geometry turbocharger, the nozzle vane including a shaft portion; and
a lever including a fitting surface to be fitted with a peripheral surface on one end side of the shaft portion, for transmitting torque to the shaft portion to adjust a vane angle of the nozzle vane,
wherein the nozzle vane is composed of nickel-based alloy,
wherein the lever is composed of stainless steel, and
wherein the lever and the one end side of the shaft portion are welded to each other, and a radiation-center position radiated by heat for welding is disposed outside a position of the fitting surface with respect to a radial direction of the shaft portion, and
wherein an expression of D/S≥0.25 is satisfied, where D is a distance between the radiation-center position and the position of the fitting surface with respect to the radial direction of the shaft portion and S is a width of weld metal with respect to the radial direction of the shaft portion.

### Claim 6 (depends on 5)

A variable geometry turbocharger, comprising:
the joint structure of a nozzle vane and a lever according to claim 5;
the turbine wheel; and
a compressor driven by the turbine wheel.

### Claim 7

A method of joining a nozzle vane and a lever by welding, comprising:
providing
a nozzle vane to be disposed in an exhaust passage for guiding exhaust gas to a turbine wheel of a variable geometry turbocharger, the nozzle vane including a shaft portion and being composed of nickel-based alloy, and
a lever including a fitting surface to be fitted with a peripheral surface on one end side of the shaft portion, for transmitting torque to the shaft portion to adjust a vane angle of the nozzle vane, the lever being composed of stainless steel; and
welding the lever and the one end side of the shaft portion by radiating heat to the lever and the one end side of the shaft portion so that a radiation-center position is disposed outside a position of the fitting surface with respect to a radial direction of the shaft portion, and
wherein heat is radiated so that an expression of D/S≥0.25 is satisfied, where D is a distance between the radiation-center position and the position of the fitting surface with respect to the radial direction of the shaft portion and S is a width of weld metal with respect to the radial direction of the shaft portion.