US 12,121,998 B2
Brazing a stacked body with a screen
Masahiro Ariyama, Tokyo (JP); Yohei Hatano, Tokyo (JP); and Hiroshi Kumagai, Tokyo (JP)
Assigned to Mahle International GmbH, (DE); and Mahle Filter Systems Japan Corporation, (JP)
Appl. No. 17/798,069
Filed by Mahle International GmbH, Stuttgart (DE); and Mahle Filter Systems Japan Corporation, Tokyo (JP)
PCT Filed Feb. 5, 2021, PCT No. PCT/EP2021/052765
§ 371(c)(1), (2) Date Aug. 6, 2022,
PCT Pub. No. WO2021/156417, PCT Pub. Date Aug. 12, 2021.
Claims priority of application No. 2020-019366 (JP), filed on Feb. 7, 2020.
Prior Publication US 2023/0080566 A1, Mar. 16, 2023
Int. Cl. B23K 35/02 (2006.01); B23K 1/00 (2006.01); B23K 1/008 (2006.01); B23K 1/19 (2006.01); B23K 1/20 (2006.01); B23K 35/28 (2006.01); B23K 35/38 (2006.01); B23K 101/14 (2006.01)
CPC B23K 35/0238 (2013.01) [B23K 1/0012 (2013.01); B23K 1/008 (2013.01); B23K 1/19 (2013.01); B23K 1/206 (2013.01); B23K 35/286 (2013.01); B23K 35/38 (2013.01); B23K 2101/14 (2018.08)] 20 Claims
OG exemplary drawing
 
1. A brazing method, comprising:
forming at least one brazing sheet into a plurality of plates;
stacking the plurality of plates to form a stacked body of a heat exchanger;
housing the stacked body in a screen to cover and enclose a periphery of the stacked body; and
brazing the stacked body under an atmosphere of inert gas without flux and bonding a portion of the plurality of plates that overlap each other;
wherein:
housing the stacked body in the screen includes forming an overlapping margin between the stacked body and a brim portion of the screen;
at least 70% of a top face of the stacked body is disposed outside of the overlapping margin and defines a heat receiving surface area of the stacked body;
the at least one brazing sheet includes at least three layers;
the at least three layers includes a core material, a brazing material layer, and an intermediate layer;
the at least three layers are cladded with an outermost layer being the brazing material layer;
the intermediate layer is disposed on at least one face of the core material;
the core material is composed of a first aluminum alloy including at least one of (i) 0.20 weight % to 1.0 weight % of Cu, (ii) 0.8 weight % to 1.8 weight % of Mn, and (iii) 0.25 weight % to 1.5 weight % of Mg;
the intermediate layer is composed of a second aluminum alloy including 0.20 weight % or less of each of Si and Fe and 0.10 weight % or less of each of Cu, Mn, and Cr;
the brazing material layer is composed of a third aluminum alloy including 10 weight % to 15 weight % of Si and 0.25 weight % to 1.5 weight % of Mg, the third aluminum alloy having a melting point of 575° C. or less according to a DSC method;
at least one of the second aluminum alloy and the third aluminum alloy include 0.02 weight % to 0.25 weight % of Bi; and
a fluid coefficient of the brazing material layer on a side on which the intermediate layer is disposed is, according to a drop type flow test, in a range of 0.40 to 0.60.