Broach for multi-head inner spiral groove of slender pipe

Abstract

The invention discloses a broach for a multi-head inner spiral groove of a slender pipe, which is applied to the field of machining of inner spiral grooves of heat exchange pipes and mainly comprises a broach body, rough broaching section broach teeth, finish broaching section broach teeth, chip containing grooves and chip breaker grooves. The broach is of a layered multi-tooth structure, the tool teeth at the same position between the layers are collinear, and the independent cutting machining removal amount can be configured for each section of the tool teeth; the structure and the size of a cutter tooth cutting edge are designed and calculated according to an internal thread groove and a back engagement parameter; one chip containing groove axially penetrating through the broach body is designed between every two adjacent broach teeth on each layer; finally, one chip breaker groove extending from the front cutter face of each cutter tooth to the boundary of the chip pocket in an unequal-width mode is designed at the front end of each cutter tooth; when the broach is used for machining the multi-head inner spiral groove of the slender pipe, one-time rough and finish machining broaching forming can be achieved, efficiency is high, the stable consistency of the forming shape and the size is good, the chip containing groove is in an axial straight-through mode, the problems that cutting chips are prone to blocking and the broach is cooled are solved, and the service life of the broach is prolonged.

Description

technical field [0001] The invention belongs to the field of processing spiral grooves in heat exchange tubes, in particular to a multi-head internal spiral groove broaching tool for slender tubes and its design technology. Background technique [0002] Adding internal spiral grooves in the pipe can improve the flow stability and speed of gas or liquid medium. Nowadays, when processing the multi-head internal spiral grooves of slender tubes, the internal spiral extrusion molding method is usually used. The extrusion molding tools generally have low service life, poor shape and size consistency, and large residual stress of the workpiece, which requires additional heat treatment for stress relief. process, resulting in increased cost and poor environmental compatibility. There is also a process of using a planer to plan a number of inclined grooves on the flat strip, and then crimping and welding the strip to form a multi-head internal thread grooved pipe. However, this meth...

AI Technical Summary

Problems solved by technology

However, it is difficult for ordinary broaches to process dozens of lines of internal spiral grooves at the same time. If the traditional small number of teeth broach is used to broach multiple internal spiral grooves with multiple positions, it is easy to cause the error of the helix angle between multiple heads, and it is necessary to complete it at one time. In multi-head internal spiral groove processing, the number of teeth of the broach is too large, the chip space between the cutting teeth is extremely small, it is difficult to remove chips during processing, and it is also difficult to provide good cooling performance for the tool

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