Honda uses single-sided spot welding to strengthen the body of the 'Accord'

Honda adopted the single-sided spot welding technology on the new 'Accord/Accord Tourer' which began to be sold in Japan on December 5, 2008. It is possible to directly weld each part of the closed section to produce a lightweight and strong car body. With the continuous enhancement of the strength and rigidity requirements of the car body, even the car body that usually adopts spot welding of thin plates has more and more closed sections. If two steel plates are bonded and a space is created between the two steel plates, the part surrounded by the walls can move like a box or a steel pipe, and the strength and rigidity can be improved. However, even if a closed-section structure is partially realized, it is difficult to make the entire vehicle body a closed section. To make the whole into a closed section, the parts must be welded. The inner and outer skins, and the outer and outer skins, are welded, respectively, in the closed section. However, spot welding is generally performed by clamping the workpiece through 2 joints. Most of the space between the inner skin and the outer skin is only a few centimeters. Since the larger welding torch cannot enter, it is difficult to weld the inside and outside separately. Therefore, in many cases, the inner and outer skins are flattened at the joints and then welded. It was difficult to make a closed section, but this part became one piece. Parts of 1 block are easily deformed, thereby losing the advantage of a closed section. Therefore, the auxiliary struts are often mounted with bolts from the rear. In addition, for welding, a work hole extending into the welding torch is sometimes drilled. The closed section is deformed from the opening. Honda has developed a technique for spot welding by pressing the electrode only from one side. The electrode inserted from the other side has the function of applying a pressing reaction force and flowing an electric current. By improving the cross-sectional shape, welding sequence, etc., the fixture can basically bear the reaction force. For example, in Fig. 3, the four lower panels (members on the side of the vehicle body) are welded by normal two-side spot welding to form a solid closed-section member. In this way, even if the strength of one-side spot welding is increased, large deformation will not occur. In addition, the robot has been improved to allow current to flow to other contacts.