CNC Machining (below)

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The measure that 6 balances handling time improves work efficiency is using lathe of double tool carrier treatment is same kind of workpiece, if use different technology, efficiency can differ a lot of. The core here is cycle time namely the balance problem of handling time. Among this, it is before, hind balance of the handling time between two working procedure, 2 it is every working procedure go up, balance of the handling time between next tool carrier. If step is logical, work efficiency can rise a lot of. If pursue,8-11 and graph 8-12 place are shown is turning of core of a kind of bearing when before, hind two working procedure. Before in working procedure, outfit of knife of T1, T2 is in upper tool post, outfit of T3, T4 is on next tool carrier; Hind working procedure, outfit of knife of T1, T2, T3 is on upper tool post, outfit of knife of T4, T5, T6 is on next tool carrier. Discharge craft by groovy method so, working procedure does not have the T3 knife in the graph before, after that process chart is much mediumer knife of a T7 (actual be before knife of working procedure T3 moves the) that come over, namely share of thick car of big rib ③ is put after working procedure turning. The cycle time of the working procedure before in those days is 61s, the cycle time of working procedure is 89s after. This workpiece is big batch treatment, before ask when working procedure very loose, hind working procedure 1, ministry of cutting of small oily channel and essence of small external diameter cut a ministry; 2, raceway essence cuts a ministry; 3, small end panel is thick cut a ministry; 4, small external diameter and raceway are thick cut a ministry; 5, ministry of lard channel cutting; 6, ministry of big rib cutting and end panel essence cut a ministry. Time is very close, the influence machines efficiency. The first measure is hind the working procedure before working procedure moves to go to the knife, if plan institute is shown. The working procedure before before uses 3 knives, it is stage of a knife holds two knives namely, another knife stage makes up a knife, no matter how be arranged, on, the handling time of next tool carrier cannot be balanced. Go up now, after next tool carrier install two knives each, course of cutting of again reasonable arrangement, make go up, next tool carrier end cutting at the same time almost, retreat a knife at the same time. The cycle time of the working procedure before such making falls to 72s, at this moment hind the cycle time of working procedure is 78s. So far, of foreword of go to work go up, next tool carrier cut work time is a balance, and before, hind the handling time of working procedure still lopsided. Observation is informed, hind of working procedure go up, the time that next tool carrier machine, an end is early, an end differs late very big. Then, after working procedure in 6 knives, 3 outfit are in upper tool post, 3 outfit fall in the premise of next tool carrier, made plan of 4 kinds of cutting, via computation and actual cutting, chose now this plan: Make go up, next tool carrier end basically at the same time cutting and retreat a knife, cycle time also is 72s. So far, not only before, hind working procedure is respective on, next tool carrier handling time achieve a balance, and before, hind the cycle time of working procedure also achieved a balance. A also can say, this is optimal program. If before, hind working procedure forms a product line, that end the cycle time of this a gleam of by original 89s, fall for present 72s, shortened the handling time of 19 ％ , make work efficiency rises apparently. The cutting of problem constant linear velocity that the attention answers when cutting of linear velocity of 7 use constant also calls fixed linear velocity cutting, its implication is to be in turning blame is cylindrical inside, when external diameter, rotate speed of lathe main shaft can change continuously, in order to maintain the cutting linear velocity of position of real time cutting changeless (constant) . The numerical control lathe that above blocks in has this function commonly. Use this function not only can improve work efficiency, still can improve the quality that machines the surface, namely the end panel that cutting gives or cone the consistency of exterior surface roughness that wait is good. 8-13 of to in an attempt to uses the issue that the attention answers when this function for exemple specification here. The cutting tool in graph 8-13 (pointed) orbit dotted line expresses fast feed, solid line expresses working feed, f dot and its size are increased for the specification below. It is to should notice to top rotate speed should be restricted commonly before using this function.

If cutting tool wants to advance to leave workpiece centre of turning circle very close, must restrict top rotate speed before constant linear velocity dictates so, can appear otherwise " flying car " . By us the manual of the machine tool reachs particular installation case in this exemple, decide top rotate speed does not exceed 3000r ／ Min. According to workpiece material and the case that use cutting tool, cutting linear velocity decides to choose 200m ／ Knin. Following program is the effective machine program that graph A shows a part. 0123; T0100 of ～ of Z of ～ of N1 G50 X: N2 G97G00Xa Za S1000 M04; N3 Xb Zb S1061 T0101 M08; N4 G50 S3000: N5 G96G01Xc ZcF0. 2$200; N6 G97G00 Zd$746; N7 Xe N8 G96G01 Xg$200; N9 G97 COO Xh Zh S1500 M09; N10 G28 U0 W0 M05; N11 M02: Enroll speed limit of 3000r ／ Min here N4 paragraph inside. This " G50S3000; " the instruction also can arrive ahead of schedule in front any positions, should be in only in this exemple N5 paragraph before OK. Such result is: In the process of cutting of constant linear velocity that makes end panel, f dot and his upside cent are cutting of $200 constant linear velocity, from F the dot begins rotate speed to increase no longer, turn into constant angular velocity namely (cutting of 3000r ／ Min) , till G dot. If do not have N4 paragraph rotate speed qualifies a statement, so rotate speed continues to increase under F dot, when be being nodded to G theoretic should achieve 6366r ／ Min, this is breakneck. 2 it is to should notice this function cannot be used in speed commonly (inside G00) block. In other words, begin to reach in G96 block under, before G97 block, cannot appear commonly COO block. In this exemple, if mix the G97 in N6 the G96 take out in N8, although cone and end panel still can make cutting of constant linear velocity, but carrying out N7 paragraph arrive at the main shaft in E point process to be able to be quickened suddenly quickly from D dot namely, rise 909r ／ Min urgently from 530r ／ Min. If cutting tool already arrived,main shaft has not rise 909r ／ Min, so cutting tool can await in E dot, rise end panel of resumptive cutting of 909r ／ Min till main shaft. The 3 main shaft rotate speed that are initial drop of G96 of best cipher out, in the COO block that reachs share of volume of rotate speed change next in front. In this exemple, the rotate speed that can calculate so that B, E nods is 1061r ／ Min and 909r ／ Min respectively. Visible, the rotate speed variation before B is nodded is 1061r ／ Min. Because initial drop arrives,A is apart from between the dot longer, arrange the variation of 1000r ／ Rain before A is nodded, give only variation of 61r ／ Min stays between A, B. N2 paragraph if medium this S value wants more accurate, can leave according to span of afore-mentioned distances and A, B than coming cipher out. Additional, can calculate so that C point point is 530r ／ Min, such C are 379r/min to the rotate speed variation between E, it is than making an appointment with as a result of the length of CD and DE 4: 3, so we arrange CD to ask ascendant 216r ／ Min, 163r ／ Min rises between DE, can decrease to eliminate the latency time of cutting tool even so, improve treatment efficiency then. The circle of the spare parts of CNC Turning skill that 8 circles pour wine cup pours horn to have 3 sort commonly model, graph 8-14 is a the commonnest kind. The dotted line in the graph is face of semifinished product outline. Specific part drawing can give out the numerical value of A, B and R dimension. When treatment, first selection 80. Knife of external diameter of end panel of equilateral lozenge razor blade, the R of radius of circular arc of point of a knife of bit but the basis machines circumstance make choice of. Here selects the delegate site of the T that it is a knife with the fictitious point of a knife with left razor blade. Discuss turning plan now. Assume first car end panel, hind car external diameter. From A the dot begins, enter with labour be down cutting end panel. After cutting end panel, make cutting tool fast reach B point, cutting of interpolation of anticlockwise circular arc goes to reoccupy C dot, enter external diameter of cutting of towards the left with labour then. According to A, B, R the value begs B to nod the order that chooses coordinate at O relatively to be: First the coordinate that H of cipher out the centre of a circle nods, reoccupy R transfers through M dot but the coordinate that cipher out B nods. Basis already the coordinate that the H dot coordinate of cipher out can reach N is nodded, next the coordinate that C nods came out. This kind of advantage that machines a method is province time, grain eats to pull one knife up again after end panel need not be down cutting, 2 it is process designing simple: G03 of circular arc interpolation paragraph the I inside is 0 (can omit) , k is negative (R+r) value, need not make geometrical calculation. If change first end panel of the car after car external diameter, usable also and similar afore-mentioned method comes turning. The circle pours place of the 2nd sort of horn 8-15 that be like a graph to show. Buccal A, B, R, A, β gives out to be worth in the graph, r of radius of circular arc of point of a knife by craft make choice of. To look clearly, of semifinished product outside outline was not drawn in the graph. Choose here first external diameter of the car after car end panel. From the A besides semifinished product the dot begins, after cutting end panel downward, make cutting tool fast reach B point. The distance L of B dot and end panel can be decided oneself. The skill of this plan depends on adding to be apart from end panel L to be apart from namely this transfers line. Cutting tool enters C by B labour, interpolation of again anticlockwise circular arc walks along D, be versed in again enter E, finally - external diameter of cutting of towards the left. The B in the graph, C, D, E is worth at the coordinate 0 o'clock relatively, can use 6 datum to beg, here no longer expatiatory. The circle pours the 3rd kind of type of horn, it is to ask round horn parts with addition of end panel, external diameter, if pursue,8-16 place is shown. If precision requirement is general, what razor blade of usable and average level shows a method to machine by Zun Tu. From the A of semifinished product external diameter the dot begins, cut end panel to arrive downward B. A very small amount takes between AB and 0C, like 0.

05mm or 0.

1mm. Cutting of reoccupy small feed arrives C, labour is entered pull D up, again cutting round horn arrives E, again external diameter of cutting of towards the left. If the precision demand of round horn is high, answer to increase the accuracy class of bit accordingly. If this kind of precision demand that the circle pours wine cup is not high, the method that can show by right plan institute is machined. The relative position that the skill here is pair of end panel and round horn makes a few craft amend, in order to achieve end panel need not turning two purpose. Specific cutting measure is: From the A besides semifinished product external diameter the dot begins, after cutting end panel downward, d of fast fall back on, again cutting circular arc arrives E, again external diameter of cutting of towards the left. Those who notice correction L choose. After wanting turning end panel only end panel is not helped when be being retreated quickly, l value should be obtained as far as possible a few smaller. This basically depends on the tigidity of the clearance of machine tool slideway and tool carrier, particular value can cut a decision through trying. 9 before, hind the note when working procedure uses same program is when treatment of turning of spare parts of some axial semmetry, before, hind working procedure can be used with foreword. Lift especially below one nonstandard scroll bearing outer shroud is exemple, before the specification, hind the note when working procedure uses same program, if pursue,8-17 place is shown. Graph 8-17 place shows the periphery of section plane to need turning, it is to arrange treatment of two working procedure to finish of course. If the place in the graph is shown,the outfit of working procedure gets stuck before, working procedure wants tune after, clip is in already on the external diameter with good turning. Two working procedure use 3 same knives. Before introducing to be made early or late on lathe of a numerical control below, hind working procedure treatment. The node of the end panel of semifinished product of A since part in the graph and axes line, it is the node of transverse plane of fixed position piece and line of main shaft centre of turning circle. Because one Cheng uses same table lathe, the channel rolling a word on workpiece external diameter and small internal diameter are advanced working procedure car or hind working procedure car is OK. If this two place decide advanced process car, so the skip switch that gets on operation face plate when the working procedure before the car is pulled " OFF " side, turn this switch when the working procedure after the car " ON " side. Conversely same also. Before, hind working procedure is used same an advantage of the program not only it is OK little input and memory a program, more important is to add man-hour to be able to bring many convenience. Still be with this spare parts exemple. After the program is inputted, should debug (try treatment) , it is to debug 0P-I first of course. Test-drive gives the first, get off measure. The cutting tool that after contrasting with blueprint, decide and revises every knife compensates a value. We discover the dimension of the age of a draught animal as shown by its teeth and raceway is abhorrent, can differ sometimes 0.

08, be about to make relevant data adjust to the program at this moment: Perhaps move the measure of raceway, perhaps move the measure of the age of a draught animal as shown by its teeth. If be moved well, workpiece of the 2nd test-drive can achieve blueprint completely to ask (it is a) of course. When a batch of workpiece a car is over hind, the working procedure after tune car, open outside Shanghaiguan besides the skip that pulls face plate to go up at this moment, the knife fills and the program need not make any changing. Want the first to achieve blueprint requirement only, these another also can achieve blueprint to ask certainly. Use this kind of method to want to note a problem: Z Xiang Yuan is nodded advanced, hind working procedure is different. The origin of working procedure is nodded in A before, the origin of working procedure is nodded in B after. The distance Z between this 2 o'clock is allowance of end panel turning. The program processing of this problem is such: In N1 paragraph below add a N2 beforehand buy check block " G50 Wl " , and in this Duan Zhi head adds " ／ ' accord with. If oversight this, the work that working procedure car gives after can ask to grow a ι than blueprint, and end panel is worn basically without the car. Also can use the Z that adjusts every knife to replace program processing to knife filling value, but rise quite or program processing way is convenient, make mistake not easily also. CNC Milling