To the efficient nap of diamond and CBN millstones

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  • source:MOMEYER CNC Machining
Processing technique and machine tool institute (IFW) the agglutinate model that introduces all sorts of differring is mixed to tall hardness CBN all sorts of nap craft of diamond millstones undertook study. Conduce to the nap of pair of tall hardness abrasive tool to the acknowledge of these craft, reduce modelling round screw die wear away, generate the efficiency that improves nap flow in the light of the small outline face of miniature grinding. To improve efficiency, people uses the efficient part that makes by tall hardness and wear-resisting caustic material increasingly. To the efficient treatment of these components, the market rolled out abrasive tool of tall hardness of numerous diamond and CBN. Ensure to realize lesser sum of errors a large number of components reach even mass, abrasive tool must accept nap regularly. According to millstones agglutinate model different, need uses different nap technology. Below nap of will broken to appearance nap, dot, outline and contact come off wait for craft to undertake introductory, introduce the emphasis the outline reforming technology of millstones. Nap flow continuity expands the applied scope that enlarged all sorts of nap craft, if contact abrasion nap, it can is opposite in limits of hundreds of micron multilayer the structure of metallic agglutinate millstones undertakes figuration nap serves as abrasive tool, the diamond millstones of CBN and synthetic resin or agglutinate of pottery and porcelain all acceptability appearance nap. Nap tool assembles those who have diamond to rotate modelling round screw die, pass radial feed and axial feed, match at the same time with orbit pilot nap, can receive wants outline external form. The characteristic of nap of this kind of appearance and outline nap is flexibility tall, interface is small, nap force is lesser, but higher cost needs in process designing respect. Because kind of compensatory of nap geometry appearance was taken on outline circumgyrate dot, outline error is accordingly dinky. In addition, still need to concern the information of respect of nap of appearance of real time outline. Because repair entire plant to exist to wear away continuously, because this needs very much capital,just come true likely. We meet precision of outline of nap strategy influence the appearance according to outline precision and millstones, make an assessment to the result of nap. The nap that undertakes to develop range of millstones miniature outline studies its make clear as a result, besides nap parameter, nap is politic (groovy type, epispastic type or press type) it is likewise one affects very big factor to outline precision. When using groovy nap strategy, shape round screw die according to successive axial feed means, mobile on millstones (graph 1) . If be a kind of section that pours V form, criterion flank should use epispastic type to shape, another flank is used press type to shape. When adopting epispastic strategy, two side that pour V form outline are used epispastic shape, shape round screw die won't move on millstones with the means of successive axial feed. Pressing type nap strategy also is such, two flank are used press type to shape. The appearance of the smallest coping of the section that can create, accept the impact of millstones granularity and adhesive strength continuously. In addition, according to millstones adhesive strength different, the outline side point of view when nap the stability to the outline in grinding process, also be a critical factor. The outline with side old point of view, its wear away the trend should be less than the rough sketch with side little point of view. According to different nap, the appearance of millstones is overlaped on one hand the influence of coefficient Ud, also get on the other hand the influence of rate Qd. The taller jackknife coefficient when nap and negative rate can bring about diamond layer appearance happening closes. Nap implement wear away to accentuate as the addition of rate Qd=1 deviation. Nextpage orders system of agglutinate of brittleness of be confined to of bureau of craft of the nap that press type, be like pottery and porcelain or fragile bronze, the tall hardness millstones that is used at containing diamond or CBN especially (graph 2) . Regard nap as the tool, used those who contain different diamond material to shape round screw die, the quality coefficient of nap (shape namely the scale between the millstones makings quantity that round screw die and grinding come down) depend on round screw die is circumferential the diamond content that go up and material are qualitative. Contain content of CVD coating, diamond to be of 100% shape round screw die can achieve the biggest quality coefficient. A of craft of this kind of nap main feature is millstones the synchronism of circumferential speed changes the rate with Qd=1. This means the contact between millstones and round screw die speed did not move relatively on the dot, achieve thereby reduce shape purpose of tatty of round screw die. To the appreciably deviation of Qd=1 rate, can bring about quality coefficient to drop quickly. If rate Qd=1 deviation is ± 4% , criterion quality coefficient basis shapes what the diamond of round screw die changes rate is different, can reduce at most 60% . When the dot presses exercise to damage brittleness adhesion key is using a dot to press craft, through by shape the regular contact force between round screw die and millstones gasket is destroyed to what brittleness adhesion bolts between abrasion grain, realize the grinding of pair of millstones material. Be based on the imitate that distributings to stress of gasket of the millstones below mechanical load, millstones gasket is more deep-seated the adhesion key of place also gets bigger load, the diagnostic nondestructive that gave dot of a kind of description to press exercise to be affected to millstones gasket for this researcher development hurts a method. When using this kind of method, press gasket with diamond needle a few micron, show the volume of force at the same time. Begin to wear away in grinding process to pressing force and millstones normally the research of the relation between makes clear as a result, both between concern for linear. Control power lesser, criterion the beginning of millstones wears away bigger, of gasket suffer an effect rate is older. Can reach from this decide simply the method of feature of millstones gasket condition, carry technological process of this kind of nap, generate be helpful for accepting refrigeration lubricant and agree with the apparent millstones gasket surface of the space that discharge bits feature. The hot load that can shun work from this is damaged, if be lighted since grinding. Shape in orbit pilot after process of nap of round screw die, can use appearance outline roller to have observation to the nap state of millstones. This kind of craft basically uses at pottery and porcelain and synthetic resin stick receive. Right now, radial of gyral round screw die stands by the millstones that rotates likewise, the appearance outline of round screw die namely impress is on millstones. The preparation of the abrasive tool when processing work of complex outline face in the light of large quantities of quantities works, suit to use this kind of technology very much. The most important adjustment of craft of this kind of nap parameter is rate Qd, millstones rotates the radial feed Frd of a week and grind control rotate speed (burnish) . Be aimed at miniature outline generate, IFW development went strategy of nap of motivation of a kind of drift (graph 3a) . Generate outline pointed radius to be on millstones the sharp contrast outline of 20 μ M, the sunken form radius that is less than 20 μ M must be machined on appearance of nap round screw die. The demand of this kind of measure on processing technique is very high. In addition, wear away in the appearance of nap device achieve most hour, wants pointed shape external form cannot be generated. To avoid this kind of problem, we used new-style nap strategy. Construct only through grooving above all on millstones an edge that gives place to want an external form (graph 3b) . Continue through the means with Z of axial amlposition Δ grooving, generate margin of the 2nd appearance, the appearance fastigium on implementation abrasive tool (graph 3c) . Require two grooving action only from this, many pointed ministry appearances can be made on whole millstones width. This kind of method has been succeeded to apply the CBN millstones at agglutinate of pottery and porcelain to go up. Another advantage of this kind of method is to shape only the is used at generating appearance fastigium brim area of round screw die gets load force. The appearance stability that this means nap round screw die is taller, the stability that works because of this nap is taller also. Method of nap of pilot of another kind of contrail is nap of osculatory electric spark. Agglutinate of electric conduction of be confined to of bureau of this kind of craft (be like agglomeration bronze) , a kind of option that it is electrochemistry nap (ECD) . The element that nap process place requires can be installed inside the machine tool, because this is OK and direct,nap undertakes to millstones on grinding axis, and need not disassemble millstones. Undertake grinding to agglutinate material through heating means, requires electric energy is generated by circuit. To this, an electrode in circuit passes contact and millstones and metallic join. The 2nd electrode is qualitative electrode of black lead electrode or copper, it is in nap process by millstones cutting (graph 4) . Millstones agglutinate purify carries non-conductive n grinding grain matter, between electrode surface and metallic joint place generation is equivalent to grain exceeding the clearance of the quantity. The grinding process that the joint on millstones manages basically can be divided for 4 measure. Above all, cut bits to make electric field raise on the clearance between electrode and millstones joint place from what generate. As the growth of cutting length, degree of electric field heighten is strengthened, at the same time cutting pointed ministry and metallic joint are in the span between to shorten. Once achieve enough field strength, clearance is eliminated through discharge. When discharge, cut bits to be evaporated, joint place generation is local and fused. Below the action of the centrifugal force of the refrigerant that shedding classics clearance and rotating millstones, fused cement material is gone by the platoon. Below the joint action that holds voltage Ud in the sky that sets, nap of osculatory report corrode can be used at grinding the exercise such as acute and modelling. Rate of nap report corrode can get if flow parameter carries the influence of the element such as electric current of voltage, open circuit and electrode pass rate for nothing. When reaching limiting value, electric corrode rate rises along with the accretion of flow parameter. When modelling, appearance outline is generated through orbit control, because electrode appearance is umbriferous on millstones,do not meet. Study the result makes clear, electrode journey and generated appearance present sexual relationship of a kind of line between outline. CNC Milling