The nap method of CBN emery wheel reachs his to apply

  • Time:
  • Click:243
  • source:EAGLEBURGER CNC Machining
Summary: Commented the plastics of CBN emery wheel and long acute method integratedly, analysed the characteristic of all sorts of methods and application. Emery wheel of 1 foreword CBN is in with its good grinding performance and grinding surface quality the high speed, high-powered grinding that exceeds material of high speed grinding, difficult treatment, efficient shape the treatment domain such as grinding won wide application. In grinding process, wait for action as a result of grinding force and grinding area high temperature, conglutinate, the meeting wearing bead of surface of emery wheel job gradually passivation; In the meantime, because the meeting wearing bead of surface of emery wheel job is inhomogenous wear away and lose correct primitive geometry figure; In addition, as a result of high speed grinding worry bit very petty, jam very easily surface of emery wheel job is interstitial. To make CBN emery wheel holds good grinding position from beginning to end, nap must undertake to emery wheel in grinding process. The plastics of CBN emery wheel, technology that build fighting spirit is domain of application of CBN emery wheel a quite main research task. The nap of CBN emery wheel can be divided for plastic and Xiu Rui two measure. Plastic is the macroscopical appearance through changing emery wheel, make emery wheel achieves the geometrical appearance of the requirement and dimension precision, make wear bead most advanced and imperceptible broken form grind blade tartly; Xiu Rui is to connect the past to grind the bond between bead except emery wheel, make wear a bulgy bond face, form the necessary space that hold bit, make emery wheel has optimal grinding capacity. According to particular case, plastic and Xiu Rui can be united undertake or finish at the same time, also can divide a pace to undertake. The plastic method of the emery wheel of plastic method CBN of 2 CBN emery wheel is more, doctrine of commonly used look of whittle having a car, boil press plastic law, grinding plastics law, report to machine plastic law to wait, appeared again in recent years laser plastics law. Law of turning of turning plastics law is to use odd grain diamond slate pencil of King Kong of pen, pulverous metallurgy or diamond nap piece wait for emery wheel of plastic tool turning, in order to achieve plastic goal. Slate pencil of King Kong of odd grain of plastics of slate pencil of odd grain King Kong has extremely tall hardness and good wearability, the nap because of emery wheel of bond of porcelain of this commonly used Yu Tao or colophony bond CBN. Of diamond pen most advanced because be heated up the concentration with force successive action, wear away acuteness, because answer when this nap,undertake cooling adequately through reasonable supply cooling fluid. After using emery wheel of CBN of bond of pottery and porcelain of nap of slate pencil of odd grain King Kong, condition of emery wheel surface achieves grinding not easily to machine a requirement, the space that hold bit is lesser, cutting blade is wider, grinding blade is not sharp, if be used at grinding directly, earlier grinding force and grinding temperature all bigger, appear easily grinding burn and Zhen Wen, because this must use oilstone,undertake reasonable Xiu Rui to the emery wheel surface after nap. Diamond piece shape nap implement plastic uses pulverous metallurgy method to written guarantee firm of grain of small size diamond go up in hard alloy matrix, make a shape nap implement. With diamond piece shape nap implement the advantage of nap CBN emery wheel is charge inferior, and piece shape nap implement change of the performance after wearing away is not big, bigger nap feed can be used when plastic and the exterior surface roughness that won't increase the emery wheel after nap. Boil press plastic law to boil controlling plastic standard is to use gyral emery wheel and roll the bond of opposite scroll fracture between drum the bridge, make collapse of the surface that wear bead broken appear small blade. Roll drum to be able to be made with hard alloy or hard steel of temper by dipping in water. Rolling the characteristic that controls plastic standard is efficiency of nap pressing muscularity, nap and nap precision surface of the emery wheel after inferior, nap injures a deeper, cutting blade density is inferior, grind bead to wear away more acerbly, easily but jam not easily. Roll pressure to reduce, increase boil press stability, can rolling drum surface to open an inclined chamfer or helix slot. Produce periodic ripple to avoid emery wheel appearance, must control emery wheel axis and the coaxial that roll axle to spend. Law of plastics of grinding of grinding plastics law is to use the as arenaceous as CBN wheel pair such as gyro wheel of common abrasive emery wheel, diamond emery wheel, diamond to grind plastic, or have plastic with mild steel of grinding of CBN emery wheel. Plastics of grinding of common emery wheel uses green carborundum or emery wheel of bond of Baigang jade pottery and porcelain regards plastic as emery wheel, outside using, round filing has plastic to CBN emery wheel. Brake is installed on axis of plastic emery wheel, make opposite rate produces between plastic emery wheel and CBN emery wheel, can improve plastic efficiency, opposite rate is older, plastic efficiency is taller. This method also can use Yu Xiurui, but should use fine size (emery wheel of nap of 150# ～ 220#) . The characteristic of law of plastics of apply the brake is plastic pressure bigger, rigid to grinder demand is high, had produced plastic easily to colophony bond emery wheel. Plastics of grinding of mild steel of plastics of mild steel grinding is to use what form when mild steel of grinding of CBN emery wheel to shed shape to cut bits to blow eliminate bond, achieve plastic goal. This method can part law of the platen that it is sheet and double platen way again. Double platen law is to use the rate difference of two platen to realize smooth plastics, can improve plastic quality. The characteristic of plastics of mild steel grinding is nap efficiency and nap precision inferior, grind bead to fall off quality of more, plastics is flabby calm. The nap of cup form emery wheel that the village of university of Tokyo of Japan of plastics of cup form emery wheel manages Ke Xiong is developed implement turn into nap feed cut feed, raised nap precision. After using plastic of emery wheel of pottery and porcelain of CBN of cup form arenaceous wheel pair, the surface of CBN emery wheel grinds a generation tiny and broken, have the good chamfer that hold bit and acerb cutting blade. The plastic effect excel of emery wheel of CBN of cup form arenaceous wheel pair uses the plastic effect of diamond emery wheel. Gyro wheel of diamond of plastics of diamond gyro wheel is to use eletroplate law or pulverous metallurgy law are in knot of diamond grain firm of metallic matrix circumferential apparently those who make is efficient shape nap tool, its repair whole mechanism is to pass the opposite motion that produces between the whirligig of diamond gyro wheel and CBN emery wheel to realize emery wheel plastics. Nap feed Ar and Q(q=vr/vs of nap speed ratio, vr is linear velocity of diamond gyro wheel, vs is linear velocity of CBN emery wheel) have main effect to the grinding function of emery wheel of the CBN after nap. The force of grinding of CBN emery wheel after using nap of Q= of bigger nap speed ratio is lesser, but workpiece surface surface roughness is bigger. Use bigger nap feed the emery wheel after Ar nap is sharper. S.

The person such as Malkin thinks, the grinding function of the emery wheel after the nap mechanism of law of plastics of diamond gyro wheel and nap basically grinds the included angle between contrail of motion of bead of stone mill of a contrail and King Kong by CBN emery wheel (control of interference horn D) , d is bigger, nap force is smaller, but the emery wheel surface after nap is rougher. The choice limits of speed ratio is Q=0 in.

4 ～ 0.

7, speed ratio Q<-1 should be chosen when accurate grinding.

0, particular numerical value should ask to decide with emery wheel character according to grinding surface roughness, speed ratio Q<-1 can be used when spare parts of grinding nicety zirconia for example.

Emery wheel of pottery and porcelain of 0 nap CBN, can obtain inferior surface roughness so (Ra=0.

06µm) and taller circularity (0.

6µm) . The main good point of law of plastics of diamond gyro wheel is a structure simple, gyro wheel durability is tall, can be at the same time on emery wheel complete width have time of nap, nap force of short, nap can be small, duplicate specific emery wheel outline (be opposite especially complex model face emery wheel has accurate answer look. This method is in have carry or empty all can use below the circumstance, can make nap time and other treatment assist time across coincide. Report machines plastic way cable to machine plastic law to be able to be used at metallic bond emery wheel only, basically electrolysis, electric spark law waits. Electrolysis is used at plastic to compare difficulty relatively. Law of electric spark plastics is to use rotate the electricity that pulse scintilla discharge produces between emery wheel and tool electrode corrodes a phenomenon to come the metallic bond that corrode eliminates emery wheel appearance, in order to achieve plastic and long acute goal. In process of electric spark plastics, the pulse of electric spark discharge of the generation between emery wheel and tool electrode forms discharge indentation in emery wheel surface, in re-ignition process, discharge indentation overlaps each other, want emery wheel nap form to place gradually. The characteristic of electric spark nap is treatment force small, comfortable Yu Xiaozhi the nap of diameter and paper-thin emery wheel; If deserve to be mixed with high accuracy electrode reasonable discharge parameter, can realize plastics of pair of fast, high accuracy that become molding sand annulus conveniently. The CBN emery wheel with the commonly used method building fighting spirit of 3 CBN emery wheel repairs acute method to freedom grinds a Xiu Rui knot of law, solid repairs acute tool to repair acute law, report to machine Xiu Rui law, laser Xiu Rui law. Arenaceous Xiu Rui of gush of gas of law of the free Xiu Rui that wear bead with carborundum, corundum or glass bead wait for free to grind bead to regard Xiu Rui as medium, with compress air to will repair eject of acute medium high speed to arrive surface of rotational CBN emery wheel, with purify part bond, form cutting blade, achieve the goal of the emery wheel that build fighting spirit. When using method of aeriform gush arenaceous Xiu Rui, should choose abrasive bead diameter, spraying pressure and long acute time correctly. The glass that is 100 ～ 150µm with bead diameter for example bead, the pressure with 60 ～ 70KPa (or the WA grain of 50µm of the diameter that use bead, with pressure of 100 ～ 140KPa) undertake gush arenaceous Xiu Rui to CBN emery wheel, need several minutes to be able to achieve the satisfactory result that build fighting spirit only. Supersonic and oscillatory Xiu Rui is rotated with fixed rate by long emery wheel, the will ultrasonic oscillatory device that build fighting spirit adjusts syntonic position, make by certain frequency and amplitude exceed frequency fore-and-aft vibration. Will mix oily abrasive (20# engine oil + carborundum or corundum wear bead) infuse arrives Xiu Rui implement with emery wheel between, use the energy that nap component delivers and active flutter, make free grinds bead to bump emery wheel surface directly, undertake cutting purify to bond, make CBN wears a face of bulgy emery wheel, achieve better nap result. The experiment makes clear, when the obligate clearance between CBN emery wheel and nap component is less than free to grind the 1/2 of an average size, space size does not have an influence to compiling acute result. Stretch Xiu Rui will mix emery wheel of CBN of oily abrasive infuse and nap component between, drive the abrasive that mix oil to pass the space of emery wheel and nap component by gyral emery wheel, free grinds bead to squeeze grind the bond on CBN emery wheel repairs acute purpose with achieving. Grind bead to come up against hard particle when free when CBN wears bead, can change direction or concede, and special cutting and crowded grind soft particle bond, at the same time the natural flutter of component of the nap in nap process also enhanced nap result. Flexibility repairs acute law to be able to repair acute CBN emery wheel effectively, and the appearance precision that won't destroy emery wheel, can wear the average size of bead through choosing nap, well and truly control CBN grinds the bulgy height of bead. Law of stretch Xiu Rui is commonly used the Xiu Rui at emery wheel of colophony bond CBN. Free grinds an extruding to repair acute to use pressure (also but need not pressure) carborundum or corundum the inject that wear bead arrives CBN emery wheel and steel nap annulus between, both clearance should is less than grind an average diameter. Free grinds bead to squeeze grind the bond on CBN emery wheel, make emery wheel wears a bulgy bond face, achieve the goal that build fighting spirit. When repairing emery wheel of CBN of acute colophony bond with this law, initiative wear away bigger, grinding is lower. Arenaceous Xiu Rui of hydraulic pressure gush this method is to use high-pressured liquid and the end that grind the motion of bead to obtain bond of surface of purify emery wheel. High-pressured pump outputs cooling fluid with restricting the flow of the pressure of 15MPa and 20 L/min, cooling fluid enters vortical room to form negative pressure, and from side aperture inspiratory and much air is mixed the medium that build fighting spirit (carborundum or corundum dissociate grind a) , after mixing with cooling fluid, arrive with fixed rate and obliquitous A eject through nozzle of pottery and porcelain surface of rotational CBN emery wheel. Arenaceous Xiu Rui of gush of hydraulic pressure of travel of the reentry after rolling plastics of emery wheel of wheel pair CBN with diamond (the time that build fighting spirit is 30 seconds) , can achieve the favorable result that build fighting spirit. If emery wheel has plastic only, surface roughness of emery wheel surface is 10 ～ 15µm; If arenaceous Xiu Rui of hydraulic pressure gush undertakes again after plastic, criterion surface roughness of emery wheel surface can increase 30 ～ 35µm. The exterior surface roughness after comparing Xiu Rui and CBN grind the average diameter of bead, surface of knowable CBN emery wheel grinds the bond purify quantity between bead to occupy CBN to grind the half of a diameter about. If increase the time that build fighting spirit alone, can bring about more bond by purify, make CBN grinds bead to fall off easily, because this long acute time is unfavorable,exceed the limit to build acute time. Arenaceous Xiu Rui of hydraulic pressure gush is a kind of efficient method that build fighting spirit, the satisfactory result that build fighting spirit can be achieved inside short time. With plastics of diamond gyro wheel while undertake arenaceous Xiu Rui of hydraulic pressure gush can reduce diamond gyro wheel wear away. Undertake in grinding process arenaceous Xiu Rui of hydraulic pressure gush can increase metallic excision to lead at the same time. Tool of solid knot Xiu Rui repairs acute law carborundum or corundum piece cuts Xiu Rui to repair acute piece to go up to be pressed in order to cut to CBN emery wheel to undertake Xiu Rui into speed Vfr in radius direction, xiu Rui piece grinds the hardness enough of bead to excise CBN to grind the bond between bead. Grind when CBN bead and when repairing acute piece to grind bead encountering, because CBN grinds a hardness taller, xiu Rui piece grinds bead to will happen broken. The cram in repairing acute piece to obliterate a gap is broken grind bead to conduce to pair of bond undertaking cutting, make thereby on CBN emery wheel more shallow grind bead to fall off. By the effective surface roughness of nap emery wheel and corundum piece bulk of unit width wear and tear and cut speed Vfr to concern, will be tended finally by the effective surface roughness of nap emery wheel one limiting value, this limiting value follows the accretion of Vfr and increase. Grinding of common emery wheel repairs acute to use nap annulus (carborundum emery wheel or corundum emery wheel) make grinding of the circle outside cutting pattern, repair acute CBN emery wheel. The relation of Vr of nap annulus speed and Vs of speed of CBN emery wheel should be Vr ≈ Vs-1(m/s) . Oilstone repairs acute oilstone to build fighting spirit is the method building fighting spirit with wider application, it basically passes a contact the area is broken those who wear bead is crowded grind the bond of emery wheel of action purify CBN. The bulgy height that bead wears after the oilstone that uses distinct size builds fighting spirit all is in 6 ～ 10µm. Because oilstone Xiu Rui is unavailable bigger grind a bulgy height, because this cannot be used at big cutting dosage,grinding uses the Xiu Rui of CBN emery wheel. Use oilstone to write acute law to eletroplating CBN emery wheel has minim plastic but the CBN with exorbitant or not firm union wears purify film face grain, improve those who wear bead to wait for tall sex thereby, decrease eletroplate the on size error of emery wheel face. Outside removing afore-mentioned meanses that build fighting spirit, still the club that build fighting spirit, Xiu Rui creams, tinsel is brushed, hard alloy piece, law of Xiu Rui of law of Xiu Rui of mild steel grinding, magnetic abrasive. Electric treatment repairs the report with acute commonly used law to machine the law that build fighting spirit to have electroanalysis online nap law (ELID) , electric spark Xiu Rui law, electroanalysis electric spark is compound Xiu Rui law. The efficiency that report machines the law that build fighting spirit is taller, can undertake online, v/arc be on the throne builds fighting spirit. Electroanalysis online Xiu Rui (Fakeshi shows ELID) to written guarantee to steel of monocrystalline silicon, pottery and porcelain the nicety that wait exceeds hard alloy accurate mirror grinding. Respect of round outside bearing steel grinding also obtained favorable result. Use the circle outside steel of bearing of ELID law grinding for example, use emery wheel of CBN of 4000# cast-iron bond, exterior surface roughness is Ra0 about.

020µm, the surface after grinding presses stress to be 150 ～ 400MPa. Electric spark repairs acute method to include electric spark discharge to repair nap of discharge of acute law, contact (ECDD) law, its job principle and electric spark plastics are identical. ECDD repairs acute technology to be able to make grind a bulgy quantity to be constant, can achieve high material purify rate. Apply grinding of ECDD online Xiu Rui, can reduce grinding force, prolong emery wheel life, improve grinding quality. Laser of the new-style method that build fighting spirit repairs acute law to will stimulate beam of light perpendicular illuminate go up at emery wheel, the quantity of heat that uses laser generation makes the bond portion of emery wheel surface melts evaporate or vaporization, increase emery wheel surface to grind bead to be mixed highly thereby wear a number effectively, improvement holds bit space and grind the tall sex such as bead. When scanning energy density is certain, the pulse frequency of laser and occupy sky comparing to have certain effect to compiling acute result, among them the effect of laser frequency is more distinct, frequency is taller, the effect that build fighting spirit is poorer; Increase occupy sky comparing to be helpful for improving the result that build fighting spirit; Increase laser power to conduce to increase grind a bulgy height. High-pressured water jet builds fighting spirit water column of law general high pressure is perpendicular eject at emery wheel surface, of the face of emery wheel of high-pressured wallop purify that uses water column grind bits and partial bond, increase thereby grind a bulgy height, form the enough space that hold bit. Reasonable control spraying pressure and eject are apart from, can achieve the favorable result that build fighting spirit. When grinding Ti6Al4V alloy with essence of 325#CBN emery wheel for example, use 107.

The eject distance of the spraying pressure of 1MPa and 20mm undertakes Xiu Rui, can lengthen nap significantly cycle and reduce workpiece surface surface roughness, but exorbitant spraying pressure can cause emery wheel loss. The characteristic that high-pressured water jet writes acute law is need not consider those who build acute tool to wear away, the device that build fighting spirit is simple, be controlled easily and operate. The plastic method of emery wheel of 4 epilogue CBN is more, among them better with effect of law of plastics of diamond gyro wheel, appropriate plastic method can choose according to need in be operated actually. The characteristic that CBN emery wheel repairs acute method is the action that keeps away from to wear bead to CBN, undertake in the light of bond corrode is divided directly, because this is in methods of all sorts of long acute of CBN emery wheel, effect of law of the free Xiu Rui that wear bead is better. To raise the nap technology level of CBN emery wheel, should accelerate pair of new-style nap principles and the research that its use a technology. The development of nap system should the design of the efficient nap system with first current consideration and application. At present northeast university is undertaking exceeding the research of high speed grinding and intelligent grinding technology, to it the research of relevant nap technology and intelligent nap system also afoot. CNC Milling CNC Machining