US4214925A
Expired / Lapsed
US
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Method for fabricating brazed aluminum fin heat exchangers
Assignee: Kobe Steel Ltd
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Filing: 1978-10-17
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Granted: 1980-07-29
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Expires: 1998-10-17
Abstract
Abstract In a method for fabricating a brazed aluminum fin heat exchanger comprising a pair of brazing sheets each consisting of a core sheet and a cladding of brazing material disposed on either side of said core sheet and a corrugated fin interposed between the brazing sheets and brazed thereto, an improved process comprises making at least the fin of a heat-treatable (age-hardenable) aluminum alloy in the Al-Mg-Si system containing 0.15 to 0.4% copper, assembling the fin with said brazing sheets into a brazed aluminum fin heat exchanger unit, maintaining the heat exchanger unit at a temperature between 500° C. and 570° C. for a time from 30 minutes to 4 hours, quenching the solution-treated unit to room temperature under cooling conditions which provide a cooling rate between 2.8° C./min. and 50° C./min. down to 200° C. and thereafter, age-hardening the quenched heat exchanger unit. The above heat-treatable aluminum alloy in the Al-Mg-Si system is AA 6951 or AA 6061.
Inventors
- 👤 Koji Arita
- 👤 Masahiro Chiji
- 👤 Takayoshi Asami
- 👤 Yasuhumi Karaki
- 👤 Toshihiko Endo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:17
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/0008; B23K1/0014; B23K1/19; B23P; B23P15/00; B23P15/26; C; C22; C22F; C22F1/00; C22F1/04; C22F1/05; F; F28; F28F; F28F3/00; F28F3/02; F28F3/025; B23K2101/00; B23K2101/04; B23K2101/14; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49393
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
140 words
A method for fabricating a brazed aluminum fin heat exchanger which essentially comprises a pair of brazing sheets each consisting of a core sheet and a cladding of brazing material disposed on either side of said core sheet and a corrugated fin member interposed between brazing sheets constituting said pair and brazed thereto comprising: making at least said fin member of a heat-treatable aluminum alloy in an Al-Mg-Si system containing 0.15-0.4% copper, assembling the fin with said brazing sheets into a brazed aluminum fin heat exchanger unit, maintaining said heat exchanger unit at a temperature between 500° C. and 570° C. for a time from 30 minutes to 4 hours, quenching the solution-treated unit to room temperature under conditions which provide a cooling rate of 2.8° C./min to 50° C./min down to 200° C. and, thereafter, age-hardening the quenched unit.
Claim 2
Independent Claim
140 words
A method for fabricating a brazed aluminum fin heat exchanger which essentially comprises a pair of brazing sheets each consisting of a core sheet and a cladding of brazing material disposed on either side of said core sheet and a corrugated fin member interposed between brazing sheets constituting said pair and brazed thereto comprising: making at least said fin member of a heat-treatable aluminum alloy in an Al-Mg-Si system containing 0.15-0.4% copper, assembling the fin with said brazing sheets into a brazed aluminum fin heat exchanger unit, maintaining said heat exchanger unit at a temperature between 500° C. and 570° C. for a time from 30 minutes to 4 hours, quenching the solution-treated unit to room temperature under conditions which provide a cooling rate of 2.8° C./min to 50° C./min down to 200° C. and, thereafter, age-hardening the quenched unit.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said cooling rate is within the range 2.8° C./min to 20° C./min.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said cooling rate is about 10° C./min
Claim 5
Dependent Claim
64 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 1 wherein said heat-treatable aluminum alloy in the Al-Mg-Si system is AA 6951 alloy which consists of 0.15 to 0.4% Cu, 0.2 to 0.5% Si, up to 0.8% Fe, up to 0.1% Mn, 0.4 to 0.8% Mg, up to 0.2% Zn, up to 0.15% others and the balance Al.
Claim 6
Dependent Claim
68 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 1 wherein said heat-treatable aluminum alloy in the Al-Mg-Si system is AA 6061 alloy which consists of 0.15 to 0.4% Cu, 0.4 to 0.8% Si, up to 0.7% Fe, up to 0.15% Mn, 0.8 to 1.2% Mg, up to 0.25% Zn, up to 0.15% Ti, up to 0.15% others and the balance Al.
Claim 7
Dependent Claim
45 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 4 wherein said agehardening comprises one-step age-hardening comprising maintaining said hat exchanger unit at a temperature between 150° C. and 175° C. for a time not less than 16 hours.
Claim 8
Dependent Claim
63 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 4 wherein said age-hardening comprises incremental age-hardening comprising heating said heat exchanger unit to a temperature between 150° C. and 175° C. over a period of 4 hours and subsequently maintaining said heat exchanger at a temperature between 150° C. and 175° C. for at least 16 hours.
Claim 9
Dependent Claim
62 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 4 wherein said age-hardening comprises two-stage age-hardening comprising maintaining said heat exchanger unit at a temperature between 50° C. and 100° C. for at least 10 hours and subsequently maintaining said heat exchanger at a temperature between 150° C. and 175° C. for at least 16 hours.
Claim 10
Dependent Claim
45 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 5 wherein said age-hardening comprises one-step age-hardening comprising maintaining said heat exchanger unit at a temperature between 150° C. and 175° C. for a time not less than 16 hours.
Claim 11
Dependent Claim
63 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 5 wherein said age-hardening comprises incremental age-hardening comprising heating said heat exchanger unit to a temperature between 150° C. and 175° C. over a period of 4 hours and subsequently maintaining said heat exchanger at a temperature between 150° C. and 175° C. for at least 16 hours.
Claim 12
Dependent Claim
62 words
A method for fabricating a brazed aluminum fin heat exchanger as set forth in claim 5 wherein said age-hardening comprises two-stage age-hardening comprising maintaining said heat exchanger unit at a temperature between 50° C. and 100° C. for at least 10 hours and subsequently maintaining said heat exchanger at a temperature between 150° C. and 175° C. for at least 16 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-29 | 1984-01-28 | 1984-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-29 | 1988-01-28 | 1988-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-29 | 1992-01-28 | 1992-07-29 | $7700.00 | Window Closed / Lapsed |