Joining method of dissimilar metal plates and dissimilar metal joined body

• US 8,502,105 B2
• Filed: 10/21/2010
• Issued: 08/06/2013
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Klaus Schmidt, Mazda Motor Corporation
• Original Assignee: Kobe Steel Limited, Mazda Motor Corporation
• Inventors: Sasabe, Seiji, Tanaka, Koujirou, Nishiguchi, Katsuya
• Primary Examiner(s): Yuen, Henry
• Assistant Examiner(s): Tran, Thien S
• Application Number:
  US12/909,610
• Publication Number:
  US 20110097594A1
• Time in Patent Office: 1,020 Days
• Field of Search: 219/86, 219/86.4, 219/89, 219/91, 219/91.1, 219/91.21, 219/92, 219/108, 219/109, 219/110, 219/111, 219/117.R, 428/594, 428/600
• US Class Current: 219/86.22
• CPC Class Codes: B23K 11/115 by means of two electrodes placed opposite one another on both sides of the welded parts
• CPC Class Codes: B23K 11/166 of galvanized or tinned materials
• CPC Class Codes: B23K 11/185 of aluminium or aluminium alloys
• CPC Class Codes: B23K 11/20 of different metals
• CPC Class Codes: B23K 11/24 Electric supply or control circuits therefor
• CPC Class Codes: B23K 2101/006 Vehicles
• CPC Class Codes: B23K 2101/18 Sheet panels
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2103/20 Ferrous alloys and aluminium or alloys thereof
• CPC Class Codes: C09J 2400/163 in the substrate
• CPC Class Codes: C09J 5/10 Joining materials by welding overlapping edges with an insertion of plastic material
• CPC Class Codes: Y10T 428/12347 Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]

Abstract

The joining method includes a step of lapping the aluminum alloy plate and the plated steel plate via adhesive, a pre-heating step of clamping both metal plates lapped in the lapping step between a pair of electrodes for spot welding and applying pressure thereto, and applying a current between the pair of electrodes, a cooling step of pressurizing both metal plates at a pressing force higher than that at the start of the pre-heating step in a state where conduction between the electrodes is stopped, and continuing this pressurization over a predetermined cooling time, and a welding step of pressurizing both metal plates at a pressing force higher than that at the start of the pre-heating step, and welding both of the metal plates by applying a current higher than the conduction current value in the pre-heating step between the pair of electrodes.

Claims

1. A method of joining dissimilar metal plates of an aluminum alloy plate and a plated steel plate by means of adhesion of an adhesive and spot welding,

the method comprising:

a lapping step of lapping the aluminum alloy plate and the plated steel plate via the adhesive;

a pre-pressuring step of clamping the aluminum alloy plate and the plated steel plate between the pair of electrodes and applying pressure therebetween;

a pre-heating step of clamping both of the metal plates that have been lapped in the lapping step between a pair of electrodes for spot welding and applying pressure thereto, and applying a current between the pair of electrodes;

a cooling step of pressurizing, after the pre-heating step, where both of the metal plates are pressed between the pair of electrodes at a pressing force which is higher than that at the start of the pre-heating step in a state where conduction between the electrodes is stopped, and continuing this pressurization over a predetermined cooling time; and

a welding step of pressurizing, after the cooling step, where both of the metal plates are pressed between the pair of electrodes at a pressing force which is higher than that at the start of the pre-heating step, and both of the metal plates are welded by applying a current which is higher than the conduction current value in the pre-heating step between the pair of electrodes,

wherein the pressing force of the electrodes is set to a first pressing force during a predetermined period from the start of the pre-heating step, the pressing force is increased to a second pressing force that is greater than the first pressing force in the middle of or at the end of the pre-heating step, and the pressurization is continued with the second pressing force until the completion of the cooling step and the welding step; and

wherein the pressing force in the pre-pressurization step is set to be greater than the first pressing force.

2. The joining method of dissimilar metal plates according to claim 1,

wherein as the lapping step, in addition to lapping the aluminum alloy plate and the plated steel plate via the adhesive, a steel plate that is separate from the plated steel plate is lapped on an opposite surface of the plated steel plate to the aluminum alloy plate, and

in the foregoing state, the aluminum alloy plate, the plated steel plate and the separate steel plate are mutually joined by performing the respective steps of the pre-heating step, the cooling step and the welding step.