Spare parts of alloy of two kinds of molybdenum (whorl) numerical control car machines methodological pre-test

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The intensity of molybdenum alloy, hardness all taller, tenacity is poor, sexual fragile Yi She is broken, machinability is poor, but because its have melting point tall, density is low bilge with heat the character with small coefficient, commonly used at making all sorts of high temperature parts of aviation and spaceflight. Spare parts of alloy of two kinds of molybdenum is molybdenum bolt and molybdenum bolt respectively, if attached drawing place is shown. Semifinished product supplied materials is steel bar of alloy of molybdenum of hot-rolling Ф 16mm, discover this material density is low in treatment, cuticular hardness is very tall, should be anneal remains hardness. Hardness of surface layer less than is very tall still, tenacity is poor, heat conduction is slow. Use common high-speed steel or hard alloy cutting tool to machine special difficulty. Above all, before cutting tool, hind knife face and point of a knife wear away very fast, add note cutting fluid, different cutting dosage experiments for many times below use normal, all unavailable satisfactory result, general outside treatment of round razor blade needs 4 times to change nevertheless; Next, the spare parts has a bit in cutting tool broken bits blemish appears namely when wearing away, flat end panel, broken bits phenomenon all appears when cutting off the whorl that reach a car. Round treatment reachs end panel treatment to maintain poignant case to fall in lathe tool of essence of life outside can satisfy design requirement basically, but thread machining drops broken bits to cannot avoid from beginning to end. In be machined actually M6 whorl car makes the result poorer, treatment middling produces whorl paragraph break off from ending place phenomenon, cannot avoid. Use screw die to machine only. M12 uses whorl of car of double knife of high speed of numerical control car, the effect is very ideal. As a result of two kinds of spare partses all longer, because this is actual treatment is medium, outside be versed in car whorl the pace is put in the car commonly, round → cuts off → to make the same score overall length to machine the juniorest travel. Because bolt of bolt of the M6 in craft file, M12 all does not allow to stay,have central opening, because treatment of this center lathe is medium,still need to make the same score central aperture finally. Number uses the method that section machines in car treatment, do not drill one center hole. The circle outside 12mm of section treatment Ф (diameter of M12 main aspects) → is cut off; The circle outside 6mm of section treatment Ф (diameter of M6 main aspects) → Che Zhui and → is cut off. The procedure is relatively simple, skip here. Those who require an attention is Ф round dimension treatment reachs Ф outside 6mm 5.

85 ~ Ф 5.

When 93mm, be helpful for covering apparently make thread. The circle is more than Ф outside 5.

93mm is covered control surplus big, easy happening whorl drops broken bits, be short of the tooth such as whorl not whole phenomenon. The circle is less than Ф outside 5.

Deflection of the extruding when 85mm covers silk is finite, if machine tool dimension produces wave motion, make dimension of M6 whorl main aspects is close to the limit or out of tolerance easily. When be being cut off additionally, overall length allowance needs to be more than 1.

5mm above. Cut off a knife to become blunt in case or discharge bits not free squashs, make cone of ministry of spare parts root (bolt) drop broken bits, after making the same score end panel also cannot repair. The spare parts after i.e. makes the same score end panel still has broken bits drawback. When the circle outside machining these two kinds of spare partses and overall length, the material brand of cutting tool of common hard alloy chooses YG6 or YG8, grind make angle can consult angle of cutting tool of stainless steel semifinishing machining is ground make, if use machine clip conditionally effect of cutting tool of knife treatment, use coating is better. Coating cutting tool divides deposit of photograph of the regulating the flow of vital energy and removing obstruction to it that it is content commonly (PVD) and deposit of chemical gas phase (CVD) . Compare with photograph of cutting tool of traditional hard alloy, intensity of coating cutting tool, hardness, wearability has very big rise. To hardness 55HRC the following material can execute high speed cutting, when be being machined to the circle outside these two kinds of spare partses (PVD) or (CVD) all but, use (CVD) razor blade slightly good. Cutting dosage: Rotate speed 600 ~ 900r/min. Back penetration of a cutting tool is measured 0.

3 ~ 0.

6mm. Feed 0.

2 ~ 0.

3mm/r. Because the heat in metal cutting of generation is very big, add man-hour to use the water-solubility cutting liquid that gives priority to with refrigeration. After machining appearance and overall length dimension, want to begin to machine whorl namely, when machining M6-6h whorl, chuck centering beard is accurate. Do not use screw die to wear as far as possible, use a silk implement treatment is better, because material is hard, fragile. Screw die wearing places the central line that holds screw die and work center line to have deflection a bit, the spare parts breaks off extremely easily or drop broken bits. Cover silk implement the deviation that can compensate both center line appropriately, when covering silk, use the cutting oil that gives priority to in order to lubricate is industrial soya-bean oil. When machining M12-6h whorl, the torque when because cover silk,be being machined is big, not easy clamp, bring about workpiece revolve. More serious is, as a result of the characteristic of material, whorl can arise to drop broken bits blemish badly, tooth not complete. Use front tooth cannot process the product that gives qualification. Whorl of whorl knife car is used on center lathe, use high-speed steel (cutting of W18Cr4V) cutting tool, use low speed (50r/min) treatment, reach cutting tool wear limit very quickly, cutting effect special also not ideal. And hard alloy YG8 is used on several cars, YG6, YW1 solder cutting tool and PVD of coating cutting tool, each rotate speed experiments under CVD use 1200r/min, the effect all also is paid no attention to want. Be aimed at experimental result and material character, the new treatment on decision use international is academic -- go high speed, quickly, law of fastfood knife cutting experiments. Be aimed at material character and cutting tool wear out condition, car whorl uses the high speed with greater difficulty (2100r/min) , double knife divides treatment of standard of vehicle of thick, fine. Pass the comparison of forms of pair of thread machining statement, washed out G34(to change above all pitch whorl dictates) with G32(onefold whorl cutting dictates, knife of advance and retreat must be appointed additionally, too trival) , decide use G92 and G76 process designing experiment respectively. Machine program is as follows: In treatment, knife of a whorl uses rough machining to be the water-solubility cutting fluid of the purpose in order to cool; What when the knife works, 2 whorl use finish machining to be a purpose in order to lubricate is industrial soya-bean oil, brush with wool dip in. Process designing explains: (Two programs O0001 mixes 1) above O0002 is to be based on send that division 0, T system work out, among O0001 program although omited very a paragraph long, still can see with G92 process designing far trival at using G76 process designing. (2) characteristic of form of statement of loop of cutting of two kinds of whorl: G92 whorl cutting uses means of the straight feed that take form circularly, as a result of cutting tool two side edge at the same time cutting workpiece, cutting power is greater, and the difficulty that discharge bits, because this is when cutting, two cutting blade wears away easily. It is when the whorl with cutting bigger pitch, because cutting deepness is bigger, edge wears away faster, cause screw center diameter to produce an error thereby. But the tooth that machines as a result of its precision is taller, because this is general and multi-purpose the treatment at whorl of small pitch, high accuracy. As a result of its cutting of cutting tool shift all relies on process designing to finish, machine program is so longer. Because edge wears away easily in treatment, because this is in treatment,want to often be measured. G76 whorl cutting uses means of the inclined feed that take form circularly, as a result of workpiece of cutting of odd side edge, edge is injured easily and wear away, make the whorl face of treatment not straight, horn of point of a knife produces change, and cause tooth precision poorer. But work for odd side edge as a result of its, cutting tool load is lesser, platoon bits is easy, and cutting deepness is degressive type, accordingly, this treatment method applies to the treatment of whorl of big pitch, low precision commonly. Bits of platoon of this treatment method is easy, edge treatment operating mode is better, ask in whorl precision not high case falls, this machines a method more forthright is convenient. If need to machine the whorl of high accuracy, big pitch, can use G92, G76 to mix used method, undertake whorl rough machining with G76 first namely, reoccupy G92 has precision work. Those who need an attention is the dot removing a knife when thick finish machining wants identical, in order to prevent the generation that whorl chaos buckles. (Heavy and complicated of 3)O0001 to program, make mistake easily. But coordinating a test try the base that cuts treatment to go up, serious work out, debug, finalizing the design can machine an eligible spare parts completely after the program. Be aimed at cutting tool easy the defect that wears away to drop broken bits easily with the spare parts, the measure that the knife has to choose the place through changing whorl knife in rough machining program will change cutting tool and spare parts to accept strength condition, in order to improve the working environment of both, achieve thereby lengthen cutting tool life and the effect that reduce broken bits. Use treatment of knife of the 2nd whorl to be able to win measure of stable screw center diameter additionally, assure whorl precision, amended G92 statement form effectively be short of regret. In finish machining, the knife since change whorl knife chooses the place, it is to be what two flank place has the thread that repair light " drive a knife " , whorl is actual the effect is very ideal. (4)O0002 program is concise make up easily, also can machine an eligible spare parts in practice. But in big batch production, finished product percent of pass relatively treatment of use O0001 procedure is low, main show is in from time to tome surface roughness of two flank surface differs the slight phenomenon that drop broken bits and whorl a bit. Because G76 dictates format characteristic decides,analysing a reason is, although use two knives to divide vehicle of thick, fine to avoid cutting tool likewise,wear away the influence of pair of whorl dimension precision, g76 format cannot undertake repetition the treatment of dimension of on one knife however, namely middling of our turning treatment says " the circle is full " machine abbreviation " round knife " , and in the treatment in this spare parts, must undertake however " round knife " , drop broken bits phenomenon otherwise more serious. Although G76 dictates of the format " inclined take a way " the condition getting power that feed means can improve workpiece and cutting tool, reduce workpiece to drop broken bits phenomenon, but cannot put an end to broken bits at all, and undertake in finish machining to raise place of whorl surface quality must " drive a knife " G76 format undertakes very hard also. Because this O0002 program is abandoned. And with program of rough machining of G76 work out, the methodological effect that uses program of G92 staff precision work also not beautiful. Because of the phenomenon dropping broken bits that produces from time to tome in rough machining, arrive when finish machining cannot repair. Can produce tooth not complete limitation, will bring about a spare parts to discard as useless. Reason uses O0001 program in be machined actually. Program brief introduction: (X of 1) spare parts joins to dimension. In rough machining cutting tool already machined X11.

1, and finish machining however from X11. 3 begin feed, it is to consider error, thick to the knife lathe tool wears away wait for a circumstance and the surplus of obligate, because this is in,lathe tool of thick, essence did not wear away, below accurate to the knife circumstance, lathe tool of essence of life begins a few knives is not of cutting, can use brush for workpiece wool dip in soya-bean oil ready-made. (Dot of the knife since 2) begins in Z15 surely, because machine tool rotate speed and tool carrier move quickly,be rate is very high, must give coder enough reaction time, make the machine tool is in in rotate speed and corkscrewed yarn contrail achieve the ability when was worth surely to begin to undertake whorl interpolation. Dot of the knife since knife of the whorl when beginning trial-produce is Z5. But already reached tolerancepublic errand floor level in dimension of screw center diameter in the discovery when self check, and go up endlong in whorl whorl old way and in diameter falls without taper circumstance, ring gauge person coming back comes the 3rd, when 4 whorl, have apparently abrupt ' hair is acerbity ' phenomenon, and after passing this to nod, come back very relieved. Via analysing reason hind, after be worth dot removing a knife instead Z15, the phenomenon disappears. Although wear away in cutting tool, value of screw center diameter is in just took noncombatant duty 0.

Person of the ring gauge when 05mm coming back is very relaxed still. (3) improves efficiency, reduce sheet working hours. The instruction shifts to an earlier date to quit main shaft movement namely after retreating knife U20, set M5. When tool carrier fall back on is far from workpiece, main shaft stops basically already, can begin to detect, assemble and unassemble workpiece. When detecting, give priority to with ring gauge, every detect whorl is integrated dimension, connect with ring gauge, end stop assures. From beginning to end of every 5 means in be being measured with micrometer of screw center diameter needs a value, master cutting tool wear out condition. Treatment 20mm whorl directly when, the workpiece when holding clip extends chuck length to be 26mm, decide Z0 for knife of program origin hencoop with workpiece end panel, machine another 14mm, when whorl, need a workpiece intermediate to give length instead 20mm to be able to begin to machine only, do not need to be opposite afresh knife, avoided to adapt program and wrong to knife happening possibility thereby. If be chosen conditionally,be the same as two factory, cutter hub that approve production together and razor blade, be in right the first time after the knife, changing every time wear away knife a short while can restore an ox quickly to produce, and do not need to be opposite afresh knife. Make to knife and cutting tool: With standard razor blade left Xiaoping and for fiducial to the knife, decide Z0 with workpiece end panel. Because be the same as the razor blade that the factory approves together,left facet and distance of point of a knife agree, the corkscrewed yarn that because of point of a knife of these two knives treatment gives is coincide, satisfied double knife car to make the demand of whorl. Choose 14 teeth like razor blade of conditional thick lathe tool / In, namely angle of horn of point of a knife 55 ° , pitch 1.

815mm razor blade, razor blade of lathe tool of essence of life chooses actor of point of a knife 60 ° , pitch 1.

75mm razor blade, criterion effect of whorl surface surface roughness is better. PVD of use coating razor blade or CVD all but, CVD effect slightly good. If do not have standard cutting tool and razor blade, usable YG8, YG6, YW1 solder cutting tool is cut by line cut machine tool make, in point of a knife left about 1.

5mm is in treatment to give one facet, use at to the knife. Point of a knife of lathe tool of thick, essence and control of facet distance public errand are in ± 0.

01mm, the horn after horn of whorl knife point of a knife is mixed is cut at the same time. The horn before manual blade grinds a whorl knife (the horn before big circular arc, cut bits glomerate, life is a bit good) , with before oilstone is abrade, hind the reuse after horn, also can satisfy treatment requirement, but cutting tool life is poorer. Double knife car formulates pair of knife methods of whorl, the person that have fun at can be contacted with the author, communication, discuss. Because material is machined hard really, although adopted all sorts of measure, cutting tool consume still taller, nevertheless product percent of pass can get basically assuring however, can achieve 95 % above. CNC Milling CNC Machining