Jig for holding thin cylindrical work, method for processing thin cylindrical work, and sheet film forming roll

Abstract

A holding jig (1, 2, 3) for a thin cylindrical work (W) includes a holding member (10, 10A, 10B) which holds the work (W) from an inner peripheral side and a diameter changing unit (25, 27) which changes a diameter of the holding member (10, 10A, 10B). The holding member (10, 10A, 10B) is made of metal and has a cylindrical shape and an elastically expandable or contractible diameter. The holding member (10, 10A, 10B) is configured with an outside diameter of the holding member (10, 10A, 10B) being held smaller than an inside diameter of the work (W) at the time of insertion into an inner periphery of the work (W) and being expanded after inserted into the inner periphery of the work (W) to hold the work (W) from an inner peripheral side of the work (W) with an outer peripheral surface in close contact with an entire inner peripheral surface of the work (W). The diameter changing unit (25, 27) applies at least one of an axial external force in a compressing direction or an axial external force in a tensile direction to both ends of the holding member (10. 10A, 10B) to change the diameter of the holding member (10, 10A, 10B).

Description

technical field [0001] The present invention relates to a holding jig for a thin-walled cylindrical workpiece used when machining a thin-walled cylindrical workpiece, a processing method using the holding jig, and a sheet / film forming roll. Background technique [0002] As one of the forming rolls for forming plastic sheets, films, etc., as described in Patent Document 1, it is known that in the inside of a flexible thin-walled metal outer cylinder, through the circulation space of the cooling medium, it is connected with the above-mentioned thin-walled metal outer cylinder. Forming rolls with a double-tube structure in which a high-rigidity metal inner tube is arranged coaxially on the tube. [0003] In Patent Document 1, the wall thickness of the thin-walled cylindrical body used as the thin-walled metal outer cylinder of such a forming roll is an extremely practical range, with an upper limit of 5 mm and a lower limit of 2 mm due to constraints during machining. [0004]...

AI Technical Summary

Problems solved by technology

[0012] However, if an elastic member made of a soft material such as rubber is interposed between the workpiece and the holding member, there is a high possibility that the elastic member will be deformed by the pressure during processing, so there is a problem that it cannot meet strict processing expectations.

In addition, when the elastic members are arranged alternately with the spacers, since the parts supporting the inner circumference of the workpiece are intermittent, the elastic members are likely to be further deformed by the pressure during processing, and there is a possibility that they cannot sufficiently respond to severe processing. expected question

For example, in the case of processing thin-walled rolls for extrusion molding, recently it is necessary to finish the outer peripheral surface of the workpiece at the level of micron (cylindricity) and submicron (surface roughness), and it is difficult to maintain the desired Possibility of machining accuracy

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