DISSIMILAR MATERIAL JOINING DEVICE AND RESISTANCE-WELDING DEVICE USED THEREFOR

To provide a dissimilar material joining device which can weld tabular members to be joined having different melting points even in mass production resistance-welding equipment with use of a robot.SOLUTION: A tabular second members 2 to be joined having a low melting point is pinched by tabular first members 1 to be joined such as a steel plate having a high melting point, a pinch part is pinched by opposite electrodes 7, 8 as a junction, and pressurization and electric conduction are performed, thereby joining both members 1, 2. At that time, the first member 1 to be joined itself is plastically deformed to previously form a small protrusion 4 at the junction of the first member 1 to be joined. Consequently, when the junction including the small protrusion 4 is pinched by the opposite electrodes 7, 8, and pressurized and electrically conducted in the state that a projection tip of the small protrusion 4 is brought into contact with the second member 2 to be joined, a large electric current flows to the projection tip of the small protrusion 4 having a small contact area to rise a temperature thereof, the second member 2 to be joined having a low melting point is molten by a heat quantity thereof, and the first members 1 to be joined are molten and solidified through a molten part thereof, and are welded.SELECTED DRAWING: Figure 1 【課題】ロボットを用いた量産抵抗溶接設備でも融点の異なる板状の被接合部材を溶接することが可能な異材接合方法及び抵抗溶接装置を提供する。【解決手段】鋼板のような融点の高い板状第１被接合部材１でアルミ板のような融点の低い板状第２被接合部材２を挟み、その挟み込み部位を接合部位として対向する電極７、８で挟んで加圧通電し、両接合部材１、２を接合する。その際、第１被接合部材１の接合部位に、第１被接合部材１そのものを塑性変形して小突部４を予め形成しておくことにより、小突部４の突出先端部が第２被接合部材２に当接された状態で、その小突部４を含む接合部位を対向する電極７、８で挟んで加圧通電すると、接触面積の小さい小突部４の突出先端部に大きな電流が流れて大きく昇温し、その熱量で、融点の低い第２被接合部材２が溶融し、その溶融部分を通じて第１被接合部材１同士が溶融・固化して溶接される。【選択図】図１