| 摘要 |
PURPOSE:To make auxiliary parts and an expensive material unnecessary by providing an annular surplus thickness part running along a hole part, on the peripheral edge of the hole part of a casting, and packing up the hole part by melting said surplus thickness part. CONSTITUTION:When casting a casting 21, an annular surplus thickness part 22 running along a hole part 20 is formed as one body with the casting 21. Subsequently, the hole part 20 is closed up by melting the surplus thickness part 22, and a closed-up part 23 is formed. The surplus thickness part 22 is melted by a welding method of a non-consumable electrode type. For instance, it is executed by irradiating an arc to the surplus thickness part 22 from an electrode 25 of a TIG welding torch 24. That is to say, the surplus thickness part 22 is melted extending over the whole periphery by positioning the welding torch 24 in the upper direction of the hole part 20, and moving an aim position of an arc generated from the electrode 25 so as to draw a periphery along the surplus thickness part 22, and the hole part 20 is closed up, and the closed-up part 23 is formed by making a molten metal flow down in the direction A on which gravity works. |
