Electric heating – Metal heating – Nonatmospheric environment at hot spot
Patent
1992-07-13
1995-02-21
Shaw, Clifford C.
Electric heating
Metal heating
Nonatmospheric environment at hot spot
2191171, B23K 1100
Patent
active
053918517
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method of welding multi-points to be welded for a short time and an object produced thereby, for example, a catalyst support for purifying exhaust gas.
BACKGROUND ART
An example of an object having multi-points to be welded includes a catalyst support for purifying exhaust gas. The catalyst support is composed of a base body formed by alternately laminating a flat sheet and a corrugated sheet and then winding them in a spiral shape, and an outer shell mounted around the outermost periphery of the base body for fixing the base body and enhancing the strength thereof. In such a catalyst support, the flat sheet needs to be welded to the corrugated sheet for preventing separation therefrom. However, there exist a number of contact points of the flat sheet to the corrugated sheet, that is, there exist a number of points to be welded corresponding to the contact points.
For joining the flat sheet to the corrugated sheet, there have been proposed techniques, for example, a brazing method disclosed in Japanese Patent Laid-open No. sho 61-199574 and a laser welding method disclosed in Japanese Patent Laid-open No. sho 63-185627.
Also, there has been proposed a method of joining the outermost periphery of the base body to the outer shell, for example, a caulking method disclosed in Japanese Patent Publication No. sho 57-55886.
However, the above brazing method disclosed in Japanese Patent Laid-open No. sho 61-199574 has a disadvantage that the metal made flat sheet or corrugated sheet is heat-affected in brazing to be deteriorated in its heat resistance.
Also, the above laser welding method disclosed in Japanese Patent Laid-open No. sho 63-185627 is a difficulty of perfectly joining all of the contact points of the flat sheet to the corrugated sheet. Accordingly, for perfect joining of all of the contact points, a laser beam needs to be scanned over the whole range of the end surface of the base body, which causes a problem of taking a long time.
Further, the above caulking method for joining the base body to the outer shell, disclosed in Japanese Patent Publication No. sho 61-199574, has a disadvantage that a joining process for the base body and outer shell must be separated from a base body forming process, thus increasing the time required for production.
Taking the above into consideration, an object of the present invention is to provide a multi-point welding method wherein multi-points to be welded are certainly welded for a short time. Another object of the present invention is to provide a method of producing a catalyst support for purifying exhaust gas wherein a flat sheet is certainly welded to a corrugated sheet for a short time thereby obtaining a catalyst support for a short time. A further object is to provide a catalyst support for purifying exhaust gas wherein a flat sheet is certainly welded to a corrugated sheet for a short time.
DISCLOSURE OF THE INVENTION
To achieve the above object, the present inventors have earnestly studied and noticed the fact that, the electric discharge machining, used in only cutting such as diesinking or wire-cut, functions to generate a large number of instantaneous electric discharges and hence to fuse the surface of the object thereby performing diesinking or wire-cut, and consequently examined the application of the above electric discharge machining to the joining process Of multi-points.
The present inventors have thus found that the above electric discharge machining is applicable to electric discharge welding by interrupting electric discharges existing at a point to be welded before the object is fused and cut, and therefore, have adopted the above technique as a multi-point welding method.
In a first aspect of the present invention, there is provided a multi-point welding method comprising the steps of: bringing points to be welded of an electric conductive first object to an electric conductive second object in contact with each other; mounting an electrode apart from the points to be welded of the fir
REFERENCES:
patent: 1827210 (1931-10-01), Siebs
patent: 2687466 (1964-08-01), Mott
patent: 3098928 (1963-07-01), Wagner
patent: 4123646 (1978-10-01), Keinanen
patent: 4282186 (1981-08-01), Nonnenmann et al.
patent: 4381590 (1983-05-01), Nonnenmann et al.
patent: 4400860 (1983-08-01), Nonnenmann et al.
patent: 4519120 (1985-05-01), Nonnenmann et al.
patent: 4521947 (1985-06-01), Nonnenmann et al.
Hashimoto Ichiro
Ito Keiji
Kawabe Yasuyuki
Matsuo Kiyotaka
Yokoi Masao
Nippon Soken Inc.
Nippondenso Co. Ltd.
Shaw Clifford C.
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