Lengthen measure of experience of tap service life

The tap collapse tooth, main reason that calls a tooth is in in attacking whorl daily, the tap collapse tooth, main reason general interest that makes a tooth sums up as follows: When ① inverts, cutting root ministry nods what squeeze cutting blade high to say " collapse tooth " . When ② inverts, cutting breaks bead is squeezed in what squeeze cutting blade between tap and workpiece to say " collapse tooth " . ③ pledges as a result of workpiece material too sticky hard, if lubricate bad, stick cutting blade, say " collapse tooth " . ④ pledges as a result of workpiece material too hard, carry the tooth on the head, say " hit a tooth " . ⑤ encounters workpiece to sand holes, material pledges not all nugget, carry the tooth on the head, say " hit a tooth " . The collision that ⑥ unreasonable operation causes, like the speed of interrupted cutting head of fast, discrepancy collides etc, cause drop a tooth to say " hit a tooth " . Because most person does not have disclosure,reason ① is its destroy the seriousness of ability. For example the exercitation factory of institute of technology of power sea profession -- limited company of machinery of day Nuo numerical control, numerical control arbor of production, arbor rear all has opening of a silk, it is respectively: Model M16 of 40 series correspondence, model M20 of 45 series correspondence, model M24 of 50 series correspondence, appeared the problem with tap not chief service life, it is for the most part bring about because of collapse tooth discard as useless. This problem also is generally in other brother unit at the same time, all put in this one problem in countrywide mechanical manufacturing industry even. Because this problem attacks whorl, general accuracy machine tool to attack machine tool of whorl, numerical control to attack whorl to exist in handiwork, great to the destruction of tap, should cause everybody's attention. The reason that problem generation analyses below reachs the way to deal with a situation. 2.

Solve measure shows 1 times through the graph above all undertake demonstrative: Graph 1 in workpiece is fixed, tap rotates, advocate cutting blade mark is E, carry bits blade mark on the back to be F. Graph 1a is tap cutting, tap contrary to reason or one's expectation, break cutting, in order to facilitate eduction; Graph 1c is tap carries bits blade F on the back, cut off cutting, leave high point G, the horn after height is tap needs a value (of EF arc length hind horn needs height) ; Graph 1d is the tap collapse tine that brings about because of nodding G high. Graph the work with 1 major simple material, should carry bits blade F on the back to back down to cutting root ministry around, can carry cutting on the head (1b seeing a picture) , but can stay have high point, if continue to back down, go with the back bits blade F shovels high point short or cut off cutting (1c seeing a picture) , continue to back down again, what be filled with too namely is mandatory regressive, because be to contain 6 ° ～ at the back of tap the cant of the horn after 8 ° , to advocate be filled with too near cutting blade E the biggest, be filled with extruding the most easily too, make advocate cutting blade collapse ages (1d seeing a picture) . Present machine uses tap cutting blade shorter, main with 2 buckle half or so to undertake cutting, especially a bit bigger diametical tap, surplus of odd blade cutting is large, the workpiece material that encounter is qualitative a little sticky hard, nod G high fight force to increase, right now tap dies the most easily tine, because this bit taller top fights the active force when active force and cutting, it is to cutting blade two-way exhaustion is destroyed alternately, dropped the abiding limit of tap blade ministry greatly, the M12 tap that the graph is shown 2 times is sliver (did not attack) , after inverting advocate the photograph with cutting bit more exorbitant blade. Raised place is high point G namely, advocate after cutting blade is bit more exorbitant, high point point has apparent attrition to shine trace, but raised apparent still, create tap collapse a tooth-like part of anything extremely easily. Graph 2 operate through a large number of practice, discovery inverts to be counted less at cutting blade when tap 1/0 when, namely 3 blade tap inverts little invert at tap of 1/3, 4 blade little at 1/4, the probability that tap collapse ages falls for lowest, want tap to invert only, break cutting, easy platoon bits can, can achieve regressive goal, need not let advocate cutting blade is bit more exorbitant G, because nod G extruding high to bring about collapse tine,can prevent tap effectively so. Operate by hand especially, use advocate cutting blade has feel bit higher nevertheless very much, achieve a goal very easily, more awl of not easy fracture of wire. When motor-driven attacks whorl, no matter benchwork or lathe work also had controlled regressive route as far as possible, avoid hard advocate cutting blade declines exorbitant point, can improve the life of tap greatly so. For example, we did not control regressive route before, m12 whorl is attacked on Z512 bench drill (the slide block of F214 boring head that production controls 100 times, every 6 M12 whorl, whorl deep 18mm, via, material qualitative 40G) general need uses 2 above tap, most a long time has used 6 tap, since realising the harm sex that chooses pair of tap high, control regressive route hard, do not let as far as possible advocate cutting blade is bit more exorbitant G (foot switch is controlled) , successive two months produced 3 batches (the first batch 105, the 2nd batch 105, the 3rd batch 103) , result tap life rises greatly, among them the first batch uses 2 tap, the 2nd batch uses 1 only (because do not have collapse tooth, when producing the 70th, tap ground gently before blade) , the 3rd batch used 2 tap, but the first tap does 81, the 2nd tap does 22 only, the tap in this process is in good condition nondestructive. Secure because of the program about numerical control machine tool, common handlers cannot change use course, so inextricability this problem, produce manufacturer to suggest to numerical control machine tool here, undertake adjustment to program of numerical control machine tool, make machine tool handlers can around of own set tap rotates the journey. When motor-driven attacks whorl, also had controlled regressive route as far as possible, avoid hard advocate cutting blade declines exorbitant point, can improve the life of tap greatly so. Show through moving research and development, numerical control machine tool attacks whorl to be collapse tooth for the most part to the attaint of tap, if do not die tooth, blunt can repair simply grind tap front, made sharp reoccupy, if collapse tooth is undeserved,repair grind. 3.

Epilogue did not take afore-mentioned problems seriously before, because book is medium,be after telling us generally tap to every advancement is measured certainly, 1/2 of inverse 1/4 ～ , make cutting breaks, easy eduction can. Through consulting a few books, discovery all attributes this kind of statement to attacking the description of whorl among them. Reason adopts practice, suggest teaching material should change somewhat according to actual condition: 4 blade tap is inverse should little at 1/4, 3 blade tap is inverse should little at 1/3, make cutting breaks, easy eduction but. So, mechanical colleague should arrive use the plant survey with much tap, understand the reason with overmuch attaint of the tap when numerical control machine tool attacks whorl, adjust existing craft hard, improve the service life of tap, for managing model the society contributes a force. Bibliographical reference: [1] Lu Ping.

Benchwork craft learns [M] .

Beijing: Machinist trade publishing house, 1979.

[2] labor and office of teaching material of social security ministry.

Benchwork craft and skill train [M] .

Beijing: Press of Chinese labor social security, 2001.

Unit: Author of institute of technology of power sea profession: At lustre wave Lin Qinggui CNC Milling CNC Machining