| 摘要 |
An improved boring bar for machining bearings in an engine block or the like includes a plurality of circumferentially spaced wear pads which extend radially beyond the surface of the bar and form the sole points of support between the bar and the inner race of a bearing in which the bar is slideably received. Preferably, at least two of the wear pads are radially displaceable within slots on oposite circumferential sides of longitudinally aligned cutting tools which are secured to the bar. The pads are removably mounted in the slots within the bar by screws to allow rapid replacement of the pads due to wear. A thin layer of resilient material, such as neoprene rubber, is captured between the radially displaceable pads and the bottom of the slot, and urge the pads away from the bar, thereby biasing the bar in a direction away from the cutting tools and toward one side of the inner race of the bearing. The constant lateral biasing of the bar eliminates tool chatter and improves machining accuracy. Existing bars may be retrofitted with the wear pads. The bar may be made of soft steel so as to flex rather than break or crack when subjected to extraordinary bending forces.
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