Center

Abstract

The invention discloses a center, which comprises a core rod, wherein the front end of the core rod is provided with a core rod head, the front end surface of the core rod head is provided with a chuck which is closely contacted with the end surface of a shaft piece, an installation hole I which passes through the core rod is arranged inside the core rod in the axial direction, an installation hole II which passes through the core rod head is arranged inside the core rod head in the axial direction, a movable thimble is arranged inside the installation hole II, the movable thimble is matched with the installation hole II and slides freely along the installation hole, the head part of the movable thimble extends out of the chuck, the tail part of the movable thimble extends into the installation hole I, an elastic pushing structure for pushing outwards the movable thimble and a limiting structure which prevents the movable thimble from being pushed out of the installation hole II by the elastic pushing structure are arranged inside the installation hole I. The center has simple structure, convenient installation, fewer components and simple structure, reduces the precision error caused by the assembling of the center, and ensures the processing reliability of the shaft piece.

Description

technical field [0001] The invention relates to a clamping device for machining parts of a lathe, in particular to a tip for clamping the end face of a part when machining a part. Background technique [0002] Nowadays, when many lathes process shaft parts, one end of the shaft is fixed on the chuck, and the other end of the shaft is machined with a center hole corresponding to the top of the lathe, and the other end of the shaft is supported by the top. The chuck clamps the shaft by clamping the outer circle of the shaft head, so that the shaft head part of the shaft cannot be processed, and the shaft cannot be processed at one time, so the shaft needs to be clamped twice. After the second clamping, it is difficult to ensure the concentricity between the size of the processed part and the size of the part to be processed on the shaft. Not only the processing efficiency is low, but also the processing accuracy is low; Design a kind of top for the problems that arise from ti...

AI Technical Summary

Problems solved by technology

[0002] Nowadays, when many lathes process shaft parts, one end of the shaft is fixed on the chuck, and the other end of the shaft is machined with a center hole corresponding to the top of the lathe, and the other end of the shaft is supported by the top. The chuck clamps the shaft by clamping the outer circle of the shaft head, so that the shaft head part of the shaft cannot be processed, and the shaft cannot be processed at one time, so the shaft needs to be clamped twice. After the second clamping, it is difficult to ensure the concentricity between the size of the processed part and the size of the part to be processed on the shaft. Not only the processing efficiency is low, but also the processing accuracy is low; Design a kind of top for the problems that arise from time to time, such as the invention patent named "a kind of top" authorized and announced by the State Intellectual Property Office of China on February 20, 2008, the announcement number is CN201023136Y, and the patent specification discloses a kind of top The top, including the body, is provided with an axial through hole on the body, the sliding top is set in the through hole, a keyway is provided on the side of the sliding top, a positioning hole is opened on the body, and a positioning screw is set in the hole. The claw sleeve is connected to the front end of the body, and a top connecting sleeve is provided at the tail of the sliding top, and the top connecting sleeve is connected to a spring, and finally a nut restricts the spring, the top sleeve and the sliding top in the axial through hole. There are many parts, the overall structure is more complicated, the assembly is inconvenient, and the error of dimensional accuracy will be enlarged. The rotation of the sliding top is limited by the cooperation of the positioning screw and the keyway, and the limit position of the sliding top's up and down sliding is limited, which not only limits the function of the top itself, Moreover, alignment is required when installing the sliding top, which is cumbersome. If there is no center hole on the end surface of the shaft, the sliding top will lose its function; in addition, after being pulled out on the end surface of the shaft by the claw, the shaft will be held firmly by the claw. , the force of the sliding center on the end face of the shaft is far less than the pulling force of the claw, so it is not necessary to limit the rotation of the sliding center

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