| 摘要 |
<p>A contact tip for use in an electric welding torch includes an electrically conductive component or tube including a mounting end and a distal contact end extending along a longitudinal wire feed axis. The conductive component is made of copper, copper alloys or mixtures of copper powder and conductive ceramic materials synthesized by powder metallurgy methods. The size of the conductive component has been enlarged to minimize operating temperatures. The mounting end of the conductive component includes a high heat transfer mounting surface. The conductive component includes a through-bore having a large diameter portion extending from the mounting end and a small diameter portion, sized for guiding the welding wire, proximate to the distal end and extending along the wire feed axis. The outlet of the small diameter portion has no chamber but clean right-angle corners around the outlet. An elongated high temperature resistant, ceramic insert is coaxially mounted in the large diameter portion of the electrically conductive component and includes a corresponding through-bore also sized for guiding the welding wire. The insert through-bore and conductive component small diameter portion define a wire feed passageway for supporting the welding wire.</p> |
