Mechanical transmission technology group

The capture broken bolts job Guide

1 、目的：

Broken bolt removal method introduced to improve efficiency.

2 , the scope of

Apply to Jiujiang workshop staff.

3, specific regulatory requirements

3.1 using chisel method, the broken Stud out

Broken Stud slightly above the substrate, the usual approach is to use a chisel from bolt breakage along the bolt carefully chisel in the opposite direction of the precession through chisel the torque and the power generated will be broken when the bolt to rotate out. This method as applied to the bolt tie not too tight for the occasion.

3.2 using a screwdriver pull the broken Stud out

Matrix method is used for the broken Stud out join, just broken studs exposed portion of the end file, then sawed it out or cross recessed and can spin out of the broken stud with a screwdriver. If the exposed portion of a longer, you can also use pliers or pipe wrench will be trapped in the broken Stud and rotate out.

3.3 borehole method combined with wedge pull the broken Stud out

This method is the use of drilling damaged Stud, thus remove the stub. M18broken studs, for example: first of all, take a length of round bar, in the drill press to drill a12 mmbore, made into a sleeve. The break position of the sleeve on the bolt and vise clamping it by hand (easy), then

Choose after10 mmdrill bit, insert the sleeve with the hand drill hole drill (drill purpose of using this method is and ensure the drill hole is not skewed, thus ensuring drilling does not hurt and the threads of the bolt holes as well as loosen broken bolts torqued evenly). Drilled holes, choose the appropriate square taper wedge hits

Into the hole in the clamp wrench head reverse wedge twists, you can spin out the broken bolt.

3.4 the decapitation with a tapped hole welding studs removed

It harder to spin the Act's severed head studs with large diameter is very effective, especially the broken Stud does not outcrop.

(1) based on the broken Stud size suitable hex nut or nut, taking note of nut thread diameterd(thread major diameter) must be less than the broken Stud pitch diameterd, designed to prevent arcing from molten metal fused into one stud and the matrix, but unable to remove broken studs. General access to smaller nuts than the broken stud with a specification, such as: studsM20, you can useM16nuts.

(2) according to common Stud and nut material (usually a35#structural steel), use of low carbon structural steel electrode can be, such asE4303, electrodes should not be too large in diameter, usually the2.5mmelectrode for welding electrodes when working in the round hole in the running.

(3) the purposes of plug hole weld. Operation shí will nut put yú matrix shàng and guarantee and broken screw column concentric; first in nut within broken screw column end head Center at, with low arc, and short shí asked intermittent spot, each spot once cleanup once welding slag and splash, after repeatedly spot, in its end Department heap welding into a round bottom diameter slightly is less than broken screw column thread trail of convex type round head. Bald head after welded, tilt rod along the bottom edge of the hole and the symmetry between the head spot. Still be spot-low arc, for a short time, uniformly continuous spot welding a week cleared after welding slag, filled spot weld parts is then closed so that the stud head and the nut hole wall is fused into one. In order to ensure adequate torsional strength, turned up bore welding the welding current. Sometimes, in order to prevent the stud tip and substrate fused into one, available diameterl 2 mmof wire volume one is slightly smaller than the nut the pitch diameter of the ring, placed studs that screw on the end hole in bottom spot.

Rotary take the broken Stud. Broken stud welding head and nut after as a whole later along with a wrench while still hot out the orientation of the spin gently twists, screw the broken Stud from the matrix. Broken Stud for larger size, suitable pipe may be used instead of the nuts, weld broken stud with a pipe wrench and rotate the pipe to rotate out.

Figure1tapped hole welding remove screws

3.5 the broken stud with a broken bolt Extractor for removal

(1) introduction to tools

Currently marketed by a broken bolt Extractor-a set of drill bits, Extractor (see figure2Ashows), sometimes accompanied by a hinge in the tool box or a set of drill bushings. The twist drill bit is the General, decollation bolt drilled out from the center of the body is made of alloy tool steel and heat treatment process with a reverse spiral, cone-shaped object.

Figure2screw Extractor

(2) using the method

First according to was broken of bolt of diameter selected suitable of bit, in broken bolt of Center drill a blind hole (as Figure2Bby shows), then selected suitable of take device body into has drill good of holes (as Figure2cby shows), with activities wrench or hinge hand frame clip live removed device body tail, inverse clockwise turned, can will fracture in body in the of bolt removed. In addition, Hexagon or a hexagon bolt failure, unable to come out, you can also use this tool to remove it.

(3) precautions for use

Often appear broken bolt Extractor Extractor for failure phenomena such as body break, cutting edge, note the rotating Extractor out broken studs are strictly forbidden to overexert in case the extractor was broken. Subject to their working conditions, remove the body of a smaller diameter (especially small Extractor body) with a Groove, easy to produce stress, unable to bear a greater torque. Remove broken bolt work, if turning resistance larger of the extractor body, must not attack, but should be taking, first of all to find out why, usually due to corrosion caused by the serious, loosening agent infiltration or shaking and other methods should be adopted, removal of rust resistance, and then remove the broken bolt.

3.6 a few pieces of advice

(1) the above methods should be selected according with flexible, composable applications.

(2) spin out broken studs should be drip before a moderate amount of lubricating oil, it is best to spray specialized loosen fluid.

(3) after spin out the broken Stud should thread to process it again with a suitable tap to remove rust in the screw hole and cán residue.

(4) before screwing the new Stud should be in the screw holes or studs put on the right amount of grease, can be effective in preventing Stud breaks.