Dimple-forming burnishing tool

Abstract

A dimple-forming burnishing tool allowing easy adjustment of a dimple shape is provided. The dimple-forming burnishing tool has a mandrel attached on a rear-end side thereof to a processing machine for rotation, and a cylindrical frame rotatably externally fitted on a tip side of the mandrel and holding a rolling element and a pressing element that are driven by rotation of the mandrel, for forming dimples in an inner surface of a workpiece by rotating the mandrel with the frame disposed inside the inner surface of the workpiece. The mandrel comprises a rolling element rotating portion causing the rolling element to rotate without moving in and out radially of the frame; and a dimple adjusting mechanism causing the pressing element to rotate while moving in and out radially of the frame.

Description

technical field [0001] This invention relates to polishing tools, and more particularly to polishing tools for forming dimples. Background technique [0002] In general, in sliding parts such as fluid bearing surfaces such as engines and hard disk drives, which are used under severe conditions of high rotation speed and high temperature, it is known to form fine grooves and Dimples to reduce the frictional resistance of the sliding surface technology. Conventionally, as a technique for forming dimples on a sliding surface, techniques such as so-called WPC treatment (fine particle peening), laser processing, or drum grinding have been used. [0003] On the other hand, buffing is a type of plastic processing in which the surface hardness and surface roughness of the workpiece are increased by crushing and deforming the processed surface of the workpiece by rotating the compacting roller while pressing the compacting roller against the workpiece. By polishing the sliding surf...

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Problems solved by technology

[0006] However, in Patent Document 1, since the cross-sectional shape of the mandrel is polygonal, both the rollers and the balls go in and out in the radial direction from the outer peripheral surface of the holder at the same time when the mandrel rotates, and it is difficult to adjust the shape of the dent (groove width). , groove length, groove depth, etc.)

In particular, if the tool is not properly arranged on the inner peripheral surface of the workpiece, the amount of movement of the rollers and balls in the radial direction at the start of dent forming changes, so stable forming processing cannot be performed, and the shape of the dent is more difficult to adjust. difficulty

In addition, in the tool described in Patent Document 1, when the tool is retracted after processing the inner peripheral surface of the workpiece, the diameter of the tool is not reduced, so there is a problem in the process of retracting the tool (so-called tool retraction). Problems with forming dents

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