Laser welded tube fitting structure and gas generator with the tube structure

• US 20050095061A1
• Filed: 03/07/2003
• Published: 05/05/2005
• Est. Priority Date: 03/08/2002
• Status: Abandoned Application

• Current Assignee: Nippon Kayaku Company Limited
• Original Assignee: Nippon Kayaku Company Limited
• Inventors: Aoki, Yasuhiro, Murai, Yasuo
• Application Number:
  US10/505,887
• Publication Number:
  US 20050095061A1
• Time in Patent Office: Days
• US Class Current: 403/272
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 26/28 of curved planar seams
• CPC Class Codes: B23K 26/282 of tube sections
• CPC Class Codes: B23K 33/006 for cylindrical workpieces
• CPC Class Codes: B60R 2021/26076 characterised by casing
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

There is provided a laser welded joint structure for a flare groove joint, wherein a flat portion 4 for forming a square-like groove in the flare groove is formed at a beam-injected portion of the flare groove on at least one side of welded members 1 and 2. There is also provided a gas generator comprising the above-described laser welded joint structure.

Claims

1. A laser welded joint structure for a flare groove joint, wherein

a flat portion for forming a square-like groove in the flare groove is formed at a beam-injected portion of the flare groove on at least one side of welded members.

2. The laser welded joint structure according to claim 1, wherein

a width of the flat portion for forming a square-like groove is 0.5 mm or more to 2.0 mm or less.

3. The laser welded joint structure according to claim 1, wherein

a width T [mm] of the flat portion for forming a square-like groove satisfies the following expression:

T≧

Q/1500

where Q represents “

laser output [W]/welding speed [m/min]”

, and is referred to as a weld-heat input or a heat input.

4. The laser welded joint structure according to claim 1, wherein

in respect of a cross-sectional microstructure of a weld metal at a laser-welded portion of the flare groove joint, a width of a surface of the weld metal is equal to or larger than a width of a portion of the weld metal just under the surface of the weld metal.

5. The laser welded joint structure according to claim 1, wherein,

in respect of a longitudinal-sectional solidification microstructure of a center of a weld metal at a laser-welded portion of the flare groove joint, a solidifying point of a surface comes in a position equal to a solidifying point of an underlayer portion located under the surface, or the solidifying point of the surface comes most behind in a processing direction of welding.

6. A gas generator comprising the laser welded joint structure according to claim 1.

7. A gas generator comprising the laser welded joint structure according to claim 2.

8. A gas generator comprising the laser welded joint structure according to claim 3.

9. A gas generator comprising the laser welded joint structure according to claim 4.

10. A gas generator comprising the laser welded joint structure according to claim 5.