Screen manufacturing method and welding apparatus thereof

Abstract

The present invention relates to a method for manufacturing a screen and welding apparatus thereof, putting a metal filter net around the outside of a support sheath and fixing the metal filter net to the outside of the support sheath by way of welding, such that the metal filter net completely covers all filter holes of the support sheath to form a filter sheath with; fixing the filter sheath to the outside of the base pipe and the filter sheath completely covering all penetrated holes on the base pipe; putting a jacket around the outside of the filter sheath and fixing it to the outside of the base pipe such that the jacket completely covers the outside surface of the filter area of the filter sheath. The present invention uses direct spot welding and seam welding technology to fix the metal net to the outside of the support sheath directly, eliminates leakage hole phenomena appearing on jointing parts of the metal net and forms the screen with multi-layer metal nets with improved sand control capability and life time. The present invention also discloses the apparatus for above-said screen to realize penetrated welding of the filter sheath so as to improve the welding quality of the metal net and lower the factory cost of the screen.

1 . A welding apparatus for the screen, characterized in that said welding apparatus comprises a welding machine and a screen drive unit; wherein the welding machine comprises at least a basal body, an arm, an inner welding head and an outer welding head; the outer welding head is mounted on the basal body and can be driven to move by an outer welding head drive unit; the inner welding head is mounted on the arm corresponding to the outer welding head, and when the outer welding head is moved in the direction to the inner welding head, they press the filter sheath of the screen from their own sides respectively; the inner welding head and outer welding head are connected with a welding power supply for supplying welding current to welding part of the filter sheath of the screen;
 a holder and a shifting device are set on the screen drive unit; the holder thereof is used for clamping the filter sheath of the screen, and the shifting device is used for moving or rotating the filter sheath of the screen in welding direction.   
   
   
       2 . The welding apparatus for the screen as claimed in  claim 1 , wherein a position limitation supporter, outside the screen, is set on the other side relative to the weld point side of the arm, which is used for preventing the displacement between the inner welding head and the outer welding head caused by deformation of the arm when the inner welding head and the outer welding head press against each other. 
   
   
       3 . The welding apparatus for the screen as claimed in  claim 1 , wherein said shifting device is to move the filter sheath of the screen to be welded along its axial direction. 
   
   
       4 . The welding apparatus for the screen as claimed in  claim 1 , wherein said shifting device is to rotate the filter sheath of the screen to be welded around its axis center. 
   
   
       5 . The welding apparatus for the screen as claimed in  claim 1 , wherein said arm is made of non-magnetic metal so as to prevent heating of the filter sheath and the arm as well as weakening of welding strength. 
   
   
       6 . The welding apparatus for the screen as claimed in  claim 1 , wherein said arm is placed upward for eliminating moving or rotating resistance of the filter sheath of the screen when moving or rotating said filter sheath of the screen.