The analysis that whorl CNC Turning machines

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Thread machining method basically is turning treatment, because whorl structure and cutting tool shift control the characteristic of the requirement, thread machining difficulty is great, tall to handlers technology requirement, technology is sophisticated, precision is not stable, manufacturing efficiency is low. Gain ground along with what a move in chess or a movement in wushu charges a machine tool, use numerical control machine tool already extensively now to machine whorl, gear (discuss and solve positive drive system) wait for each respect, rose to machine efficiency and precision greatly. At present thread machining of numerical control machine tool basically is undertake on numerical control lathe, the method of milling of useful also numerical control machines whorl, it is to use CNC Milling namely system of CNC Machining of 3 axes linkage realizes thread machining. Because itself of numerical control machine tool is in,speed control, position control and precision control the characteristic that waits for a respect, thread machining of numerical control machine tool and photograph of means of traditional thread machining are compared, in treatment the respect such as efficiency of precision, treatment has clear advantage. At present system of mainstream numerical control (FANUC, GSK) offerred onefold thread machining instruction G32, change G33 of instruction of loop of G34 of instruction of pitch thread machining, tap and whorl secure a loop to machine instruction G92, G76.

These instructions, allocate in dosage of means of course taking a knife, feed, cutting wait for a respect to have a characteristic each, apply to different thread machining. In addition, although CNC Machining raised the efficiency of thread machining and precision greatly, but face problem of a few craft as much in specific treatment. These technology issues affected the precision of thread machining and efficiency directly. Accordingly, CNC Machining whorl wants reasonable on process designing instruction alternative not only, and want reasonable on craft arrangement, ability is stable and efficient, high accuracy, reliable the ground machines whorl, produce the advantage of CNC Machining adequately. 1 screw cutting machines what process designing dictates to choose 1.

The comparison that treatment of 1 screw cutting dictates 1.

2 thread machining dictate choose thread machining to point to your format in system of different numerical control somewhat difference, but the principle is identical. In short, what is appropriate to the occasion of small pitch thread machining uses G32 or G92, what is appropriate to the occasion of big pitch thread machining uses G76, change G92, G76 can be used to mix process designing when pitch whorl machines appropriate of whorl of high accuracy small pitch to machine whorl of high accuracy, big pitch with G32, G92; with G34; , use G76 rough machining first, reoccupy G92 finish machining [the whorl inside 2]; axial small diameter can use G33 process designing. Want to wait for an element character according to whorl precision, dimension, material in actual process designing and treatment logical choice, agile use above dictates 4 kinds. Below the premise that makes sure the technology asks, simplify hard program, improve process designing and treatment efficiency. The craft in treatment of 2 whorl CNC Turning is handled 2.

Material of 1 cutting tool and cutting tool structure because the characteristic of CNC Machining, lathe tool of traditional high-speed steel already cannot satisfy the need of CNC Machining. The whorl on material of Che Zhu iron uses YG kind hard alloy, che Gang material uses YT kind hard alloy, be like YT15.

Material of this cutting tool suits rough machining to suit finish machining again already, versatility is stronger. Lead the circumstance with higher demand to machining effect, can choose agree with of high speed turning get together diamond of essence of life (PCD) cutting tool. Whorl lathe tool has integral type and machine clip type, lathe tool dosage is in whorl of machine clip type to be added gradually much. The razor blade of machine clip lathe tool is divided again for hard alloy not coating razor blade and coating razor blade, former and main use treatment nonferrous metal, latter uses material of treatment steel products, cast-iron, stainless steel, alloy to wait, coating can prolong the life of bit substantially.

2.

Appearance of 2 cutting tool and feed of angle thread machining include to be mixed into the law continuously inclined into the law. No matter which are planted method, the treatment of final whorl surface is treatment of figuration cutting tool, no matter be trigonometry whorl, still be echelon whorl, the appearance of lathe tool is duplicated to go up to workpiece directly, accordingly the appearance of cutting tool is made accurate very important. In be being machined actually, particularly right plasticity material, in whorl of high speed cutting when actual tooth role can extend somewhat, so horn of point of a knife of thick lathe tool, half essence lathe tool should be less than part of academic tooth body to be worth certainly, if common thread is OK,control is in 59.

5 the left and right sides. The point of view that at the same time the angle of thick lathe tool wants to compare lathe tool of essence of life is small. Horn of point of a knife of lathe tool of essence of life also cannot be more than theoretical value. About before horn, thick lathe tool can take a little bit big (5 ~ 10) . The crucial point is sharp, facilitating platoon bits and reduce cutting resistance, cutting is light. Lathe tool of essence of life, face of the knife before must assuring and horizontal are parallel, namely the horn before radial is 0, in order to make sure tooth shape role is proper [2] .

To inside the horn before whorl takes upper limit cost. In thread machining, because helix raises horny presence, the horn after making the horn before the job when actual cutting is mixed produced a change, if pursue,1 is shown. Theoretic and character, of front cutting direction hind horn should add a helix to promote role, and front already cutting carries hind horn should subtract a helix promotes role. In actual production, when whorl of general turning small pitch, promote role because of the whorl helix of small pitch very small, change of the character after the job is not big, the horn after wanting a static state only is in normal limits (3 ~ 5) is OK and normal cutting, reason need not consider helix to promote role. But if turning is big pitch whorl or bull whorl, helix promotes role big, the horn after the horn after the job is relatively academic changes too old saying, need to do opposite attune to rectify. Nextpage can change the point of view that hold a knife, will change the character before real work. Some enterprises use a method in treatment the method to outfit knife, although the tool reference plane of cutting tool and axes become helix to promote horny point of view, traditional thread binding coming back places the planar and perpendicular Yu Luo that makes blade of two side cutting comprises lathe tool. At this moment the horn before the job of two side edge is 0, can eliminate whorl to rise horny influence, maintain two side cutting smooth, if pursue,2 are shown. Can affect a tooth so apparently model accuracy, also do not use when finish machining. 2.

3 cutting dosage maintains strict speed ratio relationship between the feed speed of rotate speed of main shaft of thread machining requirement and cutting tool. Namely main shaft every turn, cutting tool should move equably the distance of a lead. When the circle outside because general pitch is far,be more than a car every turn feed value, so main shaft rotate speed cannot optional, s of main shaft rotate speed and the product that F is worth must not be more than axial feed to restrict a cost. Once exceed, some systems can call the police [some systems meet 3]; lead decrescent, the spare parts discards as useless; more some systems can produce risk even, tool carrier bumps to chuck. On the other hand, the job of cutting tool cutting part when thread machining the condition is very abominable, not only cutting muscularity, and attrition is acuteness, calorific and serious, itself of cutting tool material also has certain restriction to cutting linear velocity. The thread machining of average size, control of S of main shaft rotate speed is in 60~ 200 R/m In can. Whorl of special large size, be necessary checking computations linear velocity (formulary V= S? D, v is linear velocity, d is the diametical) that cutting is in, no longer give uncecessary details. The machine tool that has whorl cutting function contains main shaft coder, by systematic interior parameter installs the drive of main shaft and coder to compare. When cutting whorl, the system receives main shaft coder to turn signal just moves X axis or Z axis, begin thread machining, because this wants not to change main shaft rotate speed only, can distribute car of thick car, essence of life for many times the treatment that cutting completes same whorl. Quantity of thread machining feed can consult function of material of whorl bottom diameter and cutting tool, workpiece will decide. Old way of whorl trail = - tall =0 of tooth of tall; of 2 times tooth.

54P (P is pitch) . At present the penetration of a cutting tool on average data measures data, the least value is 0.

1 Mm, this is to common thread character. But to transmission whorl, want to ask to wait for circumstance choice according to cutting tool, precision. 2.

4 workpiece and installation of workpiece of clip of cutting tool outfit want firm and smooth, consider the tigidity of workpiece itself even. Tigidity is insufficient, cannot bear the cutting force when turning, had produced big deflection, changed the centre height of lathe tool and workpiece, workpiece by drive up, form cutting deepness dash forward add, appear the phenomenon that plunge into a knife. Answer to originally workpiece outfit clip right now, can use tailstock tip to wait, in order to increase workpiece tigidity. Should decrease as far as possible when installing whorl lathe tool extend length, prevent to arbor tigidity is not worth and produce vibration. Arbor wants perpendicular at main shaft direction, assure tooth accurate semmetry. Theoretic, installation of whorl lathe tool wants to wait with rotor line highly tall. Exorbitant or too low metropolis appears the phenomenon that plunge into a knife. Installation is exorbitant, criterion penetration of a cutting tool arrives when certain deepness, knife face withstands after workpiece, increase attrition power, bend workpiece top even, cause the; that plunge into a knife to had been installed low, cut bits not easy eduction, the direction of lathe tool radial load is work center, add a horizontal stroke to take the effect of guide screw and nut clearance, cause deepness of penetration of a cutting tool ceaseless and automatic incline to is deepened, have workpiece tip thereby, appear plunge into a knife. Practical experience makes clear, is the place of good point of a knife when thick car, half fine vehicle to compare work center slightly tall 0? 1 ~ 0? 3 Mm [4] , or position of point of a knife is controlled than the 1% D of central tower above of workpiece (D expresses to be machined workpiece diameter) . Do one's best answers to make when fine vehicle point of a knife and whorl center tall. 2.

5 treatment process controls system of mainstream numerical control, in whorl pitch affirmatory condition falls, the floating rate of axis of the X when whorl cutting, Z axis is decided by main shaft rotate speed, have nothing to do with fold of cutting feed speed, namely the feed control pushbutton on machine tool face plate is invalid when thread machining, control of main shaft times is effective [5] .

When main shaft rotate speed produces change, because X axis, Z axis adds decelerate to agree completely hard, can make pitch produces an error, accordingly, cannot undertake main shaft rotate speed is adjusted when whorl cutting, should not stop main shaft more, main shaft stops to cause the likelihood cutting tool and workpiece damage. Reduce cutting tool to wear away to make sure exterior cutting quality is mixed, should use commonly in thread machining the liquid cools and lubricate. The common problem in 3 whorl process designing and treatment 3.

Chaos of 1 multi-line whorl buckles multi-line thread machining, have two kinds of cases. If the process designing of some system dictates to there is whorl head to count parameter or initiative horn parameter in the format, define a number with process designing parameter, won't appear to smash a case in disorder. If do not have, can use Z of start of process designing of deflection thread machining the method to the value, use G32 to machine bull whorl. But want to notice right now, be in every time when thread machining start locates, had better join T0200 block first (set whorl knife to be 02 knives) , cleared knife fills, call a knife to fill with T0202 afresh again next. Otherwise most system produces chaos possibly to discount an appearance. 3.

Because whorl majority is plasticity material,2 thread outside diameter are controlled, need to consider thread machining tooth model expand quantity. The workpiece diameter before general join thread machining is equal to whorl nominal diameter to subtract 0.

1P, namely whorl old way is decreased 0.

1 pitch, be out of shape according to material ability size takes older than whorl way commonly small 0.

1~ 0.

5 Mm. To cast-iron wait for brittleness material, need not consider commonly. To the transmission whorl with tall precision, want to be measured in time in treatment, cannot control dimension by experience formula. 3.

3 common to the knife thread machining can try with cutting tool directly cut pair of knives, set work with G50 at 0 o'clock. With workpiece shift cooperates G50 to set work when many treatment at 0 o'clock. General thread machining is not very tall to knife requirement, especially Z to do not have rigid limitation to the knife. But when demand of screw center diameter is high, x axis wants accurate to the knife, and X axis should leave surplus appropriately. Can fill in X axis knife in overlay is proper filling to the knife, so that control diameter dimension fills through changing a knife in treatment, had avoided to cut. 3.

When start of 4 thread machining installs car whorl, the feed of direction of whorl of cutting tool edge should rotate with workpiece main shaft the speed ratio that keeps strict concerns. And cutting tool from stop condition to arrive at designation feed speed or fall from designation feed rate for 0, drive system must have to transfer process, outside because the treatment course length of feed of this edge axial is divided,assuring to machine whorl length, still should increase cutting tool to introduce a distance 1 cut a distance with cutting tool 2. General 1&2 = P can. Accept restriction of machine tool function, when cheap machine tool is using the statement of the radial and fast feed such as G92, G76 in majority, x to should keep the distance that has a few millimeter commonly, with benefit at falling fast. Otherwise whorl radial dimension assures hard. Treatment of 4 epilogue screw cutting has specialty, want injunction of logical choice process designing not only, and should mix in parameter of angle of cutting tool material, cutting tool, cutting the many sided such as treatment process control takes step, ability assures thread machining quality and efficiency. Thread machining instruction is in different system its format somewhat difference, but the principle is identical. The basis machines the characteristic of the object and processing technique requirement, choose proper process designing way, take logical craft step, it is to obtain what ideal machines quality and treatment efficiency to assure. CNC Milling CNC Machining