Method and apparatus for multiple cutoff machining of rare earth magnet block, cutting fluid feed nozzle, and magnet block securing jig

摘要

In a method for multiple cutoff machining a rare earth magnet block, a cutting fluid feed nozzle having a plurality of slits is combined with a plurality of cutoff abrasive blades coaxially mounted on a rotating shaft, each said blade comprising a base disk and a peripheral cutting part. The slits in the feed nozzle into which the outer peripheral portions of cutoff abrasive blades are inserted serve to restrict any axial run-out of the cutoff abrasive blades during rotation. Cutting fluid is fed from the feed nozzle through slits to the rotating cutoff abrasive blades and eventually to points of cutoff machining on the magnet block.

主权项

1. A method for multiple cutoff machining a rare earth magnet block, said method comprising the steps of:
providing a multiple blade assembly comprising a plurality of cutoff abrasive blades coaxially mounted on a rotating shaft at axially spaced apart positions, each said blade comprising a core in the form of a thin disk or thin doughnut disk and a peripheral cutting part on an outer peripheral rim of the core, providing a cutting fluid feed nozzle having a cutting fluid inlet at one end and a plurality of slits formed at another end and corresponding to the plurality of cutoff abrasive blades such that an outer peripheral portion of each cutoff abrasive blade may be inserted in the corresponding slit, combining said feed nozzle with said multiple blade assembly such that the outer peripheral portion of each cutoff abrasive blade is inserted into the corresponding slit in said feed nozzle, feeding a cutting fluid into said feed nozzle through the inlet and injecting the cutting fluid through the slits, and rotating the cutoff abrasive blades to cutoff machine the magnet block while the slits in said feed nozzle into which the outer peripheral portions of cutoff abrasive blades are inserted serve to restrict any axial run-out of the cutoff abrasive blades during rotation, wherein the cutting fluid reaching the slits and coming in contact with the outer peripheral portion of each cutoff abrasive blade is entrained on surfaces of the cutoff abrasive blade being rotated and transported toward the peripheral cutting part of the cutoff abrasive blade by the centrifugal force of rotation, whereby the cutting fluid is delivered to points of cutoff machining on the magnet block during multiple cutoff machining, wherein at an initial stage of cutoff machining of the rare earth magnet block, either one or both of said multiple blade assembly and the magnet block are relatively moved from one end to another end of the magnet block in its longitudinal direction, thereby machining the surface of magnet block to form cutoff grooves of a predetermined depth in the magnet block surface, the cutoff abrasive blades are further rotated to further cutoff machine the magnet block while the cutoff grooves into which the outer peripheral portions of the cutoff abrasive blades are inserted serve to restrict any axial run-out of the cutoff abrasive blades, the cutting fluid flowing in the cutoff groove including the cutting fluid flowing from each slit in said feed nozzle and across the surfaces of the cutoff abrasive blade is entrained on surfaces of the cutoff abrasive blade being rotated whereby the cutting fluid is delivered to points of cutoff machining on the magnet block during multiple cutoff machining.