| 摘要 |
PURPOSE:To enable to simultaneously machine a couple of arc-shaped port-grooves successively by making rocking motion of a couple of cutters, in the machining method and its device for port-groove of cylindrical sleeve for a power steering device of an automobile and the like. CONSTITUTION:Rotation of the crank 24 of a crank device 22 forces the rank arm 25 to make reciprocating slide motion through the sliding sleeve 29, thereby, each of the cutters 33, 34 positioned at the top end of the arm draws a circular locus, around 2 rocking supporting point 30 acting as a fulcrum. Depths and length of the port-grooves are determined through the crank radius R of the crank device 22, the length of the crank arm 25 and the position of the rocking supporting point 30 of the rocking sleeve 29. While the crank device 22 rotates one cycle in the arrow direction, the cutter 33 draws a locus 33a-33b to machine a work in the going path and a cutter 34 draws a locus 34a-34b to machine it in the returning path. As the machining cycle proceeds, the crank radius R is increased steadily every cycle to give additional depth of cut through a spindle unit operation, two port-grooves are made up through 40 cycles, an indexing device 42 indexes the following positions of the grooves, and thus the work machining is continued. |
