| 摘要 |
PURPOSE: To improve machining accuracy in a machining apparatus for a large circular workpiece such as a dragline by supporting the apparatus displacably to a boom, and allowing it to move on an annular reference surface around a swinging axis of the boom so as to perform machining. CONSTITUTION: A spider comprising a girder installed in a workpiece 12 position a swinging support column 18 of an apparatus 10 around the workpiece 12. To the column 18 a boom 20 is attached through a bearing 22 engaged with a collar 24. At an end of the boom 20 a milling machine 34 is disposed with a head 36 directed downward so that it engages with a machine surface 14. Ends of arms 26, 28 are supported by wheel devices 38, 40 connected to brackets 42, 44. Hydraulic actuators 46, 48 raise and lowere the devices 38, 40, 45 to support arms 43, 45 of the brackets 42, 44. A drive wheel 50 is in contact with a work surface 14. In use, a template 52 is detected by a displacement converters 56, 58. |
