Long bar stock fixture for lathe

Abstract

The invention discloses a long bar stock fixture for a lathe. The end part of a fixture body is fixedly provided with a spring expanding cover, and the end part of the spring expanding cover is provided with a tapered inner hole. The end part of a pull rod is connected with an outer-cone core shaft, and the end part of the outer-cone core shaft is provided with a tapered head inserted into the tapered inner hole. The other end of the pull rod is connected with a hydraulic cylinder driving the pull rod to stretch out and draw back, and the tapered head of the pull rod is pushed by the hydraulic cylinder so as to open the spring expanding cover. When the fixture clamps a workpiece, the end part of the spring expanding cover is inserted into a shaft hole of the long bar stock workpiece, the hydraulic cylinder is used for driving the pull rod to move, and the tapered head of the end part of the outer-cone core shaft causes the spring expanding cover to be expanded and tightly supported on the inner hole of the workpiece, so that the workpiece is clamped. The fixture is simple and convenient for clamping and is matched with a self-centering center frame and a tailstock with a special cone plug for use. Only the coaxiality of three points, namely the spring expanding cover, the self-centering center frame and the tailstock is ensured, the clamping precision of an overlong bar stock can be ensured, and therefore the processing precision of the workpiece is ensured.

Description

technical field [0001] The invention relates to a workpiece clamping fixture used on a lathe, in particular to a fixture for clamping and processing super-long bar workpieces with shaft holes. Background technique [0002] Large CNC lathes with extended flat bed are especially suitable for processing workpieces with large diameter and super long bar (length-to-diameter ratio exceeding 10 or more). However, it is difficult to clamp such workpieces. To make the clamping of such workpieces stable and reliable, It is the difficulty in the design of special fixtures for this type of lathe. Due to the characteristics of the clamping of super-long bars, the range of the workpiece clamping part is relatively short, the overhang length is long, and the effect of the gravity of the workpiece itself, the farther away from the chuck, the more the workpiece hangs downward, resulting in the size of the processed workpiece. The head is big and the tail is thin and it is difficult to guar...

AI Technical Summary

Problems solved by technology

Due to the characteristics of the clamping of ultra-long bars, the scope of the workpiece clamping part is relatively short, the overhang length is long, and the effect of the gravity of the workpiece itself, the farther away from the chuck, the more the workpiece hangs downward, resulting in the size of the processed workpiece. The head is big and the tail is thin, so it is difficult to guarantee the dimensional accuracy requirements

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