Center frame

Abstract

The invention discloses an automatic-centering center frame. The automatic-centering center frame is characterized by comprising a machine box, a driving device, a translation cam, an upper pressing rod assembly, a lower pressing rod assembly and pressing head assemblies. The translation cam is arranged in the machine box in a left-right sliding mode and driven by the driving device to move left and right. An upper pressing rod of the upper pressing rod assembly and a lower pressing rod are made to swing through the translation cam, so that the pressing head assemblies located on the upper pressing rod and the lower pressing rod and the pressing head assembly on the translation cam are gathered towards the axis of a workpiece to be machined at the same time, the workpiece to be machined issupported, a supporting wheel frame of each pressing head assembly can be automatically rotated according to the shape of the outer edge face of the workpiece to be machined, and it is ensured that two supporting wheels located on each supporting wheel frame are pressed on the workpiece to be machined at the same time.

Description

technical field [0001] The invention relates to the technical field of mechanical processing equipment, in particular to a center frame for auxiliary support for processing long-axis mechanical parts. Background technique [0002] The center frame is an auxiliary support device used in the turning or grinding process of slender shaft parts, which makes it possible for high-precision machining of ultra-thin optical shafts, precision screw rods, ball screws and other parts. The conventional closed center frame used on horizontal lathes or cylindrical grinders is a combined structure of upper and lower two bodies, and three centripetal mandrels support the workpiece. When clamping the workpiece, it is necessary to open the upper body of the center frame, close the upper body after loading the workpiece, rotate the workpiece according to the circular runout value, adjust the axial movement of the mandrel, and achieve the coincidence between the support of the center frame and th...

AI Technical Summary

Problems solved by technology

Using the conventional closed steady rest, it takes a long time to adjust the concentricity of the workpiece, the precision is low, and the efficiency is low

[0003] At present, most of the existing self-centering steady frames use hydraulic cylinders as the driving force, which requires a special hydraulic station. The hydraulic components require high processing accuracy, difficult processing and assembly, limited use of space, and the production environment is prone to oil pollution and other shortcomings.

There are also some self-centering steady rests that use motor direct drive, but only one moving speed can be used during the centering process. If you choose a faster centering speed, it will cause an impact when the centering roller contacts the surface of the workpiece, directly It affects the accuracy and surface quality of the workpiece; if you choose a slower centering speed, the processing efficiency will be significantly reduced, and this method keeps the motor in the working state throughout the processing process, with high energy consumption and high heat generation. Reduced lifespan

At present, whether it is a hydraulic or electric automatic centering center frame or a manual adjustment center frame, it can only be used to support a cylindrical shaft diameter, and cannot solve the support problem of a conical shaft diameter.

For some slender shaft parts, there is no cylindrical shaft section for support at one end (only a long conical surface), and the steady frame cannot be used to improve its rigidity during processing, resulting in very high processing efficiency and processing accuracy for such parts. Low

At present, for the slender shaft parts with conical surface, only one end is clamped, the other end is clamped by the top or both ends are clamped. If the long diameter is relatively large, the rigidity of the workpiece is poor, and the workpiece is subjected to cutting force. It will produce large bending deformation, and only a small cutting amount can be used during processing. Not only the processing efficiency is extremely low, but also it is difficult to obtain high processing accuracy.

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