US4083223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nondestructive inspection method for spot-welded joints
Assignee: Nissan Motor Co Ltd
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Filing: 1976-11-10
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Granted: 1978-04-11
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Expires: 1996-11-10
Abstract
Abstract The quality of joints formed by spot welding, particularly the diameters of the individual nuggets, can accurately and nondestructively be inspected by heating or cooling one of the welded members and measuring the distribution of the surface temperature of the other member because of a maximal heat conduction at each nugget. The surface temperature distribution may be measured merely linearly since the width of a peak on the temperature-distance curve depends on the diameter of a nugget.
Inventors
- 👤 Masaru Hashimoto
- 👤 Masaya Ogata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:09
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/72; G01B; G01B11/00; G01B11/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
141 words
A method of inspecting a joint formed by spot-welding of members which comprises the steps of: varying substantially uniformly the temperature of one of the said welded members relative to the other welded members in a region including at least the joint; and measuring the distribution of temperature on a surface of the said other welded members in a region including the joint, said temperature distribution being measured one dimensionally across a parallel projection of a nugget formed in the joint on said surface, said measurement step further comprising the steps of: preparing a temperature-distance curve representing said temperature distribution; measuring the width of a temperature peak on said curve at half of the height of said temperature peak; and estimating the diameter of said nugget from said width based on a preliminarily examined relationship between said width and said diameter.
Claim 2
Independent Claim
141 words
A method of inspecting a joint formed by spot-welding of members which comprises the steps of: varying substantially uniformly the temperature of one of the said welded members relative to the other welded members in a region including at least the joint; and measuring the distribution of temperature on a surface of the said other welded members in a region including the joint, said temperature distribution being measured one dimensionally across a parallel projection of a nugget formed in the joint on said surface, said measurement step further comprising the steps of: preparing a temperature-distance curve representing said temperature distribution; measuring the width of a temperature peak on said curve at half of the height of said temperature peak; and estimating the diameter of said nugget from said width based on a preliminarily examined relationship between said width and said diameter.
Claim 3
Dependent Claim
19 words
A method as claimed in claim 1, wherein the temperature of said one of the welded members is raised.
Claim 4
Dependent Claim
16 words
The process as defined by claim 1 wherein the temperature of said welding members is lowered.
References Cited (Backward Citations)
US3206603A
Cited
US3406272A
Cited
US3434332A
Cited
US3427861A
Cited
US3566669A
Cited
US3599474A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-10 | 1981-10-10 | 1982-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-10 | 1985-10-10 | 1986-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-10 | 1989-10-10 | 1990-04-11 | $7700.00 | Window Closed / Lapsed |