| 摘要 |
PURPOSE:To increase the curvature radius of the bent section on the external surface of sealing parts that are sealed vacuum-airtightly in a flange provided at the peripheral section of a cylindrical anode by providing an annular protrusion. CONSTITUTION:A magnetic pole 3 is inserted in a flange section 1a and sealing parts 2' provided at the cylindrical anode 1 of a magnetron and the peripheral section 2'a of the sealing parts 2' is bent along the peripheral edge 3a of the magnetic pole 3 and is sealed vacuum-airtightly together with the flange section 1a of the anode 1 by arc welding. In addition, an annular protrusion 2'a whose radial width is 0.5-2mm. and whose axial protrusion height is less than 0.5mm. is provided inside it abutting to a bent section 2'b provided at the peripheral section 2'a of the sealing parts 2' and the curvature radius of the bent section 2'b of the sealing section 2' is increased. As a result, the generation of the crevices in the production process of the sealing parts 2' and the cracks while they are being used is eliminated and a fault such as faulty vacuum can be prevented. |
