JOINING METHOD FOR PLATE LIKE BODY

PURPOSE:To join the plate material having the thickness in a wide range with high efficiency and high quality by performing the beam welding of both end parts of a plate like body with high energetic density by using a backing plate, then by removing the backing plate by pressing it to a shearing device while under feeding. CONSTITUTION:A backing plate 10 is deposited by welding the terminal side 8A of the preceding coil and the start end side 8A of the succeeding coil which are continuously fed with the high energetic density of an electron beam, etc. by using the backing plate 10. The joined plate like body 8 is fed by being guided with a guide roller 12 from the upper and lower parts and abutted to a backing plate shearing device 11. The shearing device 11 is set up with the inclination theta based on the position at right angles with the plate passing line. The edge side of the backing plate 10 is therefore abutted to the shearing device 11 first and according the progress of the plate pass the shearing is performed in order from the edge side and in case of passing through the shearing device 11 the shearing is completed over the whole width. This junction method can be executed for those which having the thickness in a wide range.