Impeller brazing method

Patent metadata

Field	Value
Publication number	US-9815134-B2
Application number	US-201715402602-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Feb 22, 2011
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

The present invention relates to an impeller manufacturing method in which a thermal cycle is performed on an assembly body with a brazing material formed of a Ni-containing Au alloy being placed at a bond portion of at least two impeller constituent members. The thermal cycle includes a temperature increasing process with a temperature increasing rate of 20° C./hr. to 100° C./hr., the process including a first intermediate retention and a second intermediate retention each keeping the temperature, the first intermediate retention performed in a temperature range of 500° C. to 850° C. and the second intermediate retention performed in a temperature range of 850° C. to 950° C. (but not including 850° C.). In the thermal cycle, the temperature is increased in a temperature range exceeding 950° C. after the second intermediate retention at a rate lower than that before the second intermediate retention.

First claim

The invention claimed is:

1. An impeller manufacturing method in which a thermal cycle is performed, for bonding, on an assembly body with a brazing material interposed at a bond portion between at least two impeller constituent members, wherein
the thermal cycle includes:
a temperature increasing process of increasing a temperature to a retention temperature;
a retaining process of retaining at the retention temperature in a temperature range equal to or higher than a melting temperature of the brazing material; and
a temperature decreasing process of decreasing the temperature from the retention temperature to a room temperature, and
the thermal cycle is performed with the assembly body being placed with respect to a first heating body heating the assembly body from an inner circumferential side of the assembly body,
wherein, in the temperature decreasing process, a retention is performed in a temperature range of 930° C. to 970° C. for 0.5 to 2 hours,
wherein the first heating body is configured to protrude from a shaft hole of the assembly body such that the first heating body is heated by directly receiving heat generated externally,
wherein the first heating body is integrally provided together with a second heating body supporting the assembly body from below in a vertical direction, and
wherein the first heating body and the second heating body are configured to be a heating jig that is made of a carbon, the heating jig heated by heat generated externally.

2. The impeller manufacturing method according to claim 1 , wherein the first heating body satisfies 0.5 h 2 ≦h 1 ≦20h 2 , where h 1 is a height of the first heating body and h 2 , is a height of the assembly body.

3. The impeller manufacturing method according to claim 1 , wherein the first heating body satisfies h 2 ≦h 1 ≦10h 2 , where h 1 is a height of the first heating body and h 2 is a height of the assembly body.

4. The impeller manufacturing method according to claim 1 , wherein a size of the first heating body in a diameter direction is configured to satisfy 0.4R 2 ≦R 1 <R 2 , where R 1 is a diameter of the first heating body and R 2 is a diameter of a shaft hole of the assembly body.

5. The impeller manufacturing method according to claim 1 , wherein a size of the first heating body in a diameter direction is configured to satisfy 0.8R 2 ≦R 1 <0.95R 2 , where R 1 is a diameter of the first heating body and R 2 is a diameter of a shaft hole of the assembly body.

6. The impeller manufacturing method according to claim 1 , wherein the second heating body is disk-shaped, and is configured to have a diameter equal to or larger than an outside diameter of the assembly body.

7. The impeller manufacturing method according to claim 1 , wherein a spacer is interposed between the second heating body and the assembly body.

8. The impeller manufacturing method according to claim 1 , wherein, in the temperature decreasing process, the retention is performed at a temperature of approximately 950° C.

Assignees

• Mitsubishi Heavy Ind Ltd
• Mitsubishi Heavy Ind Compressor Corp

Inventors

• Yokoo Kazutoshi
• Tanaka Daisuke
• Kawada Daisuke
• Niihara Koshiro
• Takagi Hiroki
• Watanabe Yujiro
• Nakajima Hiroshi

Classifications

• B23K35/3013

  Au as the principal constituent · CPC title

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title

• F05D2230/237

  Brazing · CPC title

• C22C38/48

  with niobium or tantalum · CPC title

• F04D29/023

  especially adapted for elastic fluid pumps · CPC title